FIELD OF INVENTION

This invention relates to a cam mechanism. Mofe particularly, this invention relates to a cam mechanism with a biased catch mountable to a handtruck or other structure or transport for securing a lid, closure, gate or load. More particularly, this invention relates to a cam mechanism with a a biased catch for a handtruck, the biased catch being a securing device for handtruck loads of stackable containers, such as crates, totes or drums.

BACKGROUND ART

The following references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part.

The prior art and the invention will be discussed with reference to handtracks and the application of an biased catch thereto. However, the cam mechanism iwtli biased catch of the invention may be applied to other devices and be employed in other applications, such as load restraints in general transport, catches for gates, and the connection of adjacent containers or packages etc.

Handtracks are known that are adapted to carry general loads, such as boxes, furniture and the like. Stackable containers, however, create particular problems in load securement and also present opportunities to configure a handtruck to the specific sizes and shapes of stackable containers.

Generally, stackable containers, such as crates and 4.5 gallon or 20T drums, may be loaded onto a trolley and secured by straps or belts. However, workers who are prone to non-compliance in relation to occupational health and safety practices may attempt to shift such loads that are precariously balanced on the foot of a handtruck, rather than take the time and effort required to adjust, fit and attach the strap. Such operators may also over-reach and/or bend forward to secure the load whilst pulling it back to a transporting position.

The frame of a generic style handtruck generally consists of three basic elements : a handle, a frame (forming a vertical load platform) and a toe (also known as a nose) forming a horizontal platform). The size of the toe is selected based on the type of loads carried and requiring support. Loads can vary between soft bagged items (sacks) and rigid containers, such as crates or totes. Loads are generally positioned on- the toe by one of 4 methods:

1. Manually lifted and placed on the toe and also removed using a similar method;

2. ^' The load stack is tilted forward on its front edge to create space under to allow the toe to be slid under the load;

3. The load package is stabbed, for example where a thin toe is driven between the floor surface and the load with speed and/or force; and

4. A special load pallet is used that provides a space for the toe to be slid under without the action in item 2 above.

Also where appropriate, there is the necessity to secure the load with straps o other devices, most requiring a reasonable amount of time and effort to do so.

Each method has its own particular risks with regard to both worker safety and stack stability, including product security and damage, and involve relatively high levels of user force and stress, including museuloskeletal-based bending and lifting actions.

In the case of crates, totes and drums, all of these type of containers tend to have their own structural integrity comprising a substantially rigid outer skin or skeleton enabling them to maintain their shape, whilst supporting their own weight, as well as loads above them. Such rigid containers also are adapted to nest against or in one to impart additional load stack stability,

^" While the industry generall use generic handtrucks for such rigid containers, there is a substantial need in the industry for an easier, safer and faster {more productive) method of handling loads generally and, in particular, crates/totes and drums, which may ameliorate the need to bend, grab, lift or secure such containers.

Containers, particularly stackable containers, such as tote crates are used in the manual and bulk handling of goods, such as milk, bread, and other bottled or cartoned products. Tote crates may be carried in bulk, i stacked form, on pallets or maybe transported in stacked form, for example for local distribution. To assist in the handling of tote crates where individual handling of tote crates is required, the use of a handtruck negotiated by a pedestrian user may be required, Tote crates are generally stackable in stacks of two or more crates, typically 2 - 5 crates, but in some applications such as the st cking of bread crates, can be as man as 15 crates. It has been found that an intermediate crate in the stack is more unstable and likely to dislodge leading to a collapse or disturbance of the stack during transit by a handtruck. Whilst hooks extending from a handtruck have been described as useful in holding a tote crate in position on a handtruck, there are problems with poor or ineffective engagement of the hook with the tote crate, including poor engagement with tote crates stacked higher up the stack in an intermediate position.

In some arrangements, a handtruck having an attachment mechanism for a stack of tote crates would be advantageous to accommodate different sized tote crates.

Most attempts revolve around using hooks that engage and lift the stack— usually at the first or base crate, With static systems, engagement can be difficult or uncertain, depending on wheel position, frame rotation and upper level load security. In prior handtrucks, upper load security is minimal and generally requires the load to be secured manually by hand, particularly during pull back or an inclined surfaces, or by fixing a security strap or restraint prior to travel.

It is desirable to minimise over-reaching or bending of the operator, to minimise tilting of an unsecured load forward during loading or unloading, or to minimise tilting of the handtruck forward to fully engage the load with the nose, toe or foot plate.

Biased catches have use in a variety of applications, such as gate open and closure, refrigeration open and closure and load securemeiit on transport. In particular, a catch that may be deflected from a closed position to an open position and optionally releasably locked in an open position would be particularly advantageous. Furthermore, a catch that is adjustable in position so that the catch can accommodate different sized or positioned objects for retention would also be advantageous.

An object of the present invention is to ameliorate the aforementioned disadvantages of the prior art or to at least provide a useful alternative thereto,

STATEMENT OF INVENTION

The invention according to one or more aspects is as defined in the independent claims. Some optional and/or preferred features of the invention are defined in the dependent claims.

Accordingly, in one aspect of the invention there is provided :

A cam mechanism for controlling the operation of a deflectable retaining member, the cam mechanism comprising:

at least one cam and one slider to ride over a cam surface of the cam,

said cam and said slider aligned, the cam surface aligned, opposing and abutting said slider, one of said cam and said slider fixed against rotation relative to said retaining member and each of said earn and said slider having corresponding cam and slider centre points,

the other of said cam and said slider not fixed against rotation relative to said retaining member being rotatable component that is rotatable relative to the fixed one of said earn and said slider so that said slider rides against said cam surface, said cam and said slider move axially relative to one another from an axial resting position in which said cam and slider centre points lie at a first distance relative to each other, to a Spaced position in. which said cam and slider centre points arc axially spaced apart a greater second distance compared to the first distance and relative to one another; and

a bias urging said cam or said slider towards said resting position, said deflectable retaining member operatively connected to said rotatablc component so that relative axial movement of said cam centre point away from said slider centre point corresponds to deflection of said retaining member.

The slider preferably ha a surface that may be any one or more of ramped, inclined, sloped and curved . The slider preferably has a complementary and corresponding surface to the cam. The slider may be in the form of a smooth knob or protrusion. The slider may have a ramped cam-contacting surface. The slider may have another wall to support the cam-contacting surface. Preferably, the slider is another cam component.

In another aspect of the invention, there is provided:

A cam mechanism for controlling the operation of a deflectable retaining member, the cam mechanism comprising:

first and second cam components,

said first and second cam components aligned, each cam component having corresponding first and second cam surfaces that oppose and abut each other, aid first cam component fixed against, rotation relative to the retaining member and each of said first and second cam components having corresponding first and second centre points,

said second cam component rotatable relative to said first cam component so that said second cam component's cam surface rides against said first cam component's cam surface from an axial resting position in which said first and second centre points lie close to each other, to a spaced position in which said first and second centre points are axially spaced further apart relative to one another; and

a bias urging said second component towards said resting position, said deflectable retaining member operatively connected to said second component so that axial movement of said second cam component away from said first centre point corresponds to deflection of said retaining member.

In discussing the attributes of the cam, reference to the cam will also be taken to be reference to the first cam component. The cam may include a travel control key. The travel control key may restrict or prevent rotation of the cam. The travel control key may restriet or prevent rotation of the cam about the longitudinal axis of the slider or the cam component. The travel control key may be a keyed radial travel control device on the cam and may comprise a gap that may cooperate with a key in a cam bousing containing the cam. The gap may be an arc gap of a wall recess. The arc gap may be defined by an incomplete cylindrical wall forming part of the cam. The incomplete cylindrical wall defining the gap or wall recess may form part of an outer cylindrical body of the cam. The cam mechanism may include a single retaining member. The retaining member may be provided as one of a plurality of retaining members . The retaining members may be operable to move together. The retaining members may be operable to move independently.

The retaining member may one of a plurality of retaining members actuated b the cam. The cam mechanism may actuate separate rows of retaining members. The rows may be corporately or separately height adjustable. Where one or more of the rows are separately height adjustable, the adjustment mechanism may require each row to have its own spring mechanism.

The cam mechanism may include a release mechanism to disengage or remove the retaining member from the load. The release mechanism may include the use of a cable to connect multiple, or upper and lower, rows so that they act in synchronisation. The release mechanism itself ma include a cable connection operably connected to a lever or other hand operable device.

The cam mechanism may include a cam housing. The cam housing may provide a travel chamber. The second cam component may be at least partially reciptOcatabiy moveable in said travel chamber. The second component ma be trapped in the cam housing against rotation relative to the cam housing.

The firs and second cam surfaces may each have a cam surface ridge. The cam surface ridge may enable said first and second surfaces to move from a first stable position and to ride against each other up and over the ridge and down into a second stable position. In the second stable position, the force required to return the second component part back off the cam surface ridge is greater than a returning force applied b the bias.

The respective first and second cam surfaces may have complementary troughs in which the opposed cam surface may rest. When the ridges of one earn member are in the opposed troughs of the opposed cam member, the retaining member is in a stable position. The stable position may correspond to the retaining member position being either open or closed. When the opposed ridges of the corresponding first and second cam surfaces are riding over one another, the first and second centrepoints are axially spaced further apart against the force of the bias than in a stable or resting position corresponding to an open or closed position of the retaining member. The deflectable catch is in an unstable transitional state when moving between an open and a closed position.

The cam, slider and/or cam components and the deflectable catch may be mounted on a shaft such as an axle. The cam or the slider, or one of the First and second cam components, may be mounted for reciproeatable travel on the axle. One of the cam components may be fixed laterally relative to the axle so that it does not rotate with the axle or the axle rotates whilst it is fixed laterally. The deflectable retaining member is preferably mounted on the axle for rotation about the axle's longitudinal axis. The retaining member preferably extends normally from the shaft. The engaging member may be spaced from the rotatable shaft by a distance corresponding to approximatel the length of an elongate body of the retaining member.

The cams may comprise inside and outside cams. They may be in pairs, Preferably, the eammechanism comprises a pair of outsi de cams and a pair of inside sliders or second c components. The cam face or faces of the second inside cam are preferably fixed in the same latitudinal alignment or radial spacing and alignment with respect to th axle only allowing it to travel longitudinally on the axle, but fixed against rotation relative to the axle. This can be achieved in many ways, including providing a second cam outer surface profile that includes keys, splines, hex or other profiles so that the second cam slides reciprocally on the axle and rotates relative to the axle.

The first and second cam components may be axially aligned. The first and second cam components may be mounted on a first rotatabie shaft. The cam mechanism may include a second rotatabie shaft aligned so that it is spaced and parallel relative to the first shaft. The first shaft is adapted to rotate about the first shaft's longitudinal axis. The second shaft is preferably rotatabie about the longitudinal axis of said first shaft. The first and second shafts preferably each extend through the same cam housing.

The bias may be a spring. The spring is preferably mounted on or in the cam housing. The bias is preferably mounted on or about the first shaft. The bias preferably is adapted to axially urge the second component towards the centre point of the first component.

The retaining member may present a narrow bearing or supporting surface. The retaining member may present a broad supporting or bearing face to support or hold a load. The broad surface may contact the load at spaced positions to stabilise the load. The retaining member may comprise a single engaging member that engages the load. The retaining member may be a hook, latch or catch.

The retaining member is preferably a catch. The deflectable eatch may be for securing an object or load which may have an engageable member. The eatch may comprise an elongate body extending in a first direction and terminating in a catch member at a first end and a leverable end at a second opposed end. The catch member may have a remote detent member and a body wall that together define a recess for receiving the object's or load's engageable member. The elongate body may have a pivot point between the body wall. The second end may extend transversely to the first direction across the elongate body. The pivot point and the leverable end ma lie in a first plane parallel to or includin an axis of the pivot point. The recess may be positioned outside the first plane.

Preferably, a centre point of the recess is positioned at an angle of between 25 and 75°, more preferably 35 to 65 ^° , still more preferably 50 to 60°, and most preferably about 55°, relative to the first plane, taken from the pivot point. The advantage of off-setting the recess relative to the pivot point and the first plane is mechanical and enables improved leverage as the recess is located close to the pivot point and remote from the second end.

^" he relationship of the connection of the catch to the first shaft providing the pivot point for the catch relative to the position o the hook or recess provides mechanical synergy in the securement of an object engagement means, such as the object, load item or bar of the item to the catch. As the engagement means is received in the recess, pressure is applied to the inside face of the hook and the engagement means pulls into the inside hook surface, rather than away, thereby reducing risk of the catch disengaging under load.

The pivot point may include a shaft extending therethrough. Most preferably, the pivot point comprises a transverse bore, that is a bore transverse to the general longitudinal axis of the catch, extending through the catch for receiving a shaft about which the deflectable catch rotates about the longitudinal axis of the shaft. Similarly, the leverable end may comprise a transverse bore for receiving a handle shaft, or may include a handle or the like that can be manipulated by an operator pivot the deflectable catch. The handle shaft can be a plain round, splined, hex or keyed shaft for different purposes of positioning the one or more catches. In a preferred form, roll pins may be. used to fix and orientate the catch on the shaft. This provides a fixed position or orientation of the catch both radially and longitudinally in relation to the first shaft, The first outer cam is preferably longitudinally fixed in relation to the cam housing, but ma be radially or circumferentially positioned on the shaft using keys, matching spline or hex bore.

The deflectable catch ma be 'adapted to operate with the recess facing in any required orientation, down, up, sideways, etc., so that the deflectable catch may be biased to a latched position by means other than gravity, for example by a spring mounted on the shaft.

The catch body may include clamping or securing means for tying the rotation of the catch to the first shaft. For example, the catch may include a protruding lug or locating pin for insertion into a corresponding aperture in the first shaft. The catch body ma include an aperture or groove through or in which a pin may be inserted for location on the first shaft. In either case, preferably the catch moves with the first shaft, so that as the first shaft rotates about its axis, the catch pivots. Regarding the radial and longitudinal positioning of the catch, it may be advantageous to be able to move the catch longitudinally along the first shaft, with its radial or circumferential position fixed relative to the first shaft. This may be achieved with collars, clamps and the like. Preferably, such radially fixed arrangements are fixed with corresponding profiled bores on the shaft and catches (and the cam rotatably linked therewith) require only longitudinal moveable positioning. Hex, keyed or splined shafts are preferred for setting radial, relativity of the catch and the outer first cam component to fix the catch relative to the shaft radially. The catch may be secured against axial travel along the shaft by longitudinal stop or clamping means, for example by pinning or clamping.

Similarly, the first cam component may include clamping or securing means for tying the rotation of the first cam component to that of the first shaft. For example, the first cam component may include a protruding lug or locating pin for insertion into a corresponding aperture in the first shaft. The first cam component may include an aperture or groove through or in which a pin ma be inserted for location on the first shaft. In either ease, preferably the first shaft moves with the first cam component, so that as the first shaft rotates, the first cam component correspondingly rotates about its, and the first shaft's, axis. The catch will rotate due to interference, e.g. on being deflected by the bar of the crate, causing the shaft, and hence the first cam component, to rotate against a radially or circumferentially static slider or second cam component which pushes against the bias providing resistance and preference to return to the original resting position.

The second cam member may be trapped in the cam housing. The second cam component may include a key feature to ensure that the second cam member is fixed for rotation with the cam housing. The key feature may include a profile that restricts radial movement, such as a spline, hex profile, radial key o groove that cooperates with a corresponding groove or key in a travel chamber of the cam housing. The longitudinally aligned key features may permit the second cam member to move reciprocally and axially (longitudinally) within the travel chamber, but rotating relative to the first shaft.

The cam housing may be fixed to a structure to prevent rotation thereof relative to the structure. The first cam component may be fixed to a structure by itself. When the first cam component is fixed to a structure, the second shaft may not be required other than for ancillary needs, such as cable holder.

The cam housing may house a first outer pair of cams and a second inner pair of cam components. The second cam components are preferably adapted to axially slide relative to the rotatable shaft and the cam housing against the bias. The inner and outer pairs of components are preferably coaxially aligned.

The cam mechanism may be mountable to structure such as a guide in the form of a rail or track. The cam mechanism may be adjustable in position along the length of the guide. The guide may be linear or curved. The guide may form part of a transport device, Other mounting plates or structures may be provided to allow the cam mechanism to be fixed or attached to various structures. The transport device may be a handtruck or other device for transporting discrete objects. The objects may be stackable. The objects may be containers, totes, crates, cartons, boxes or the like.

The engageable member of the load object may be a flat bar, beam or other elongate member that can be engaged by the deflectable catch. Alternatively, the engageable member may be a custom formed pocket or recess.

The rotational or pivotal travel of the retaining member may be limited to be capable of rotating through an angle of 10 - 70 ^° , more preferably 30 - 60°, still more preferably 45 - 55 ^° , and most preferably 50 ^° . The rotational or pivotal travel of the retaining member preferably corresponds to the angle of the centre point of the recess relative to the first plane, taken from the pivot point.

The rotational travel of the retaining member may be limited by any of a variety of suitable mechanisms. For example, limited rotational and reciprocal travel of the retaining member may be effected by a butterfly groove arrangement, by a combination of a suitably position lug or lugs on the shaft, or limited in its travel by a detent or detents on the structure. Such an arrangement may provide a fail-safe, should the load slip off or fail to be fully supported underneath. For example, the load may be supported by a toe of a handtruck and the travel of the retaining member may be limited rotationally by a radial control mechanism so that the retaining member is prevented from full rotating through the vertical, which would otherwise permit a situation in which the load objects could fall off.

These radial controls may be configured to modify' the system for various scenarios of travel, including multiple selectable static positions in which the retaining member may be set at one of a number of optional angular positions.

In another aspect, there is provided;

a handtruck for handling a load of one or more stackable containers, the handtruck including:

a frame;

a wheel base attached to a base of the frame, the wheel base having at least one set of multiple directional wheels sharing a main axle;

a stackable container base support extending forward of the base of the frame that is adapted to support at least part of a base of a lowermost one of the containers;

a releasablc retaining means adapted to cooperate with an element of one of the containers to prevent the container from falling forward relative to the frame.

The rcleasable retaining means may be any suitable solid or rigid retaining member. The retaining member may be movable from a retaining position to a release position. The retaining member may be deflectable, slidable or rotatable. The retaining member may have an arm or shaft having a detent to cooperate with the container element. The arm or shaft may terminate in the detent. The detent may be a catch, barb, stop or hook. The retaining member may comprise a curved or concave hook. The retaining member may include a head portion with a leading ramped or cammed surface.

In another aspect, the invention provides:

a handtruek for handling a load of one or more stackable containers, the handtruek including:

a frame generally lying in a first plane and including handles for manipulation by an operator;

a wheel base attached to a base of the frame, the wheel base having at least one set of multiple directional wheels sharing a main ax le, each wheel in the set including multiple peripheral rollers adapted to travel diagonally and laterally with reference to the main direction of travel of the wheel base normal to the main axle;

a base support extending forward of the base of the frame that is adapted to support a lowermost one of the containers by engaging a downward facing surface of the lowermost container, the side of the container adjacent the frame resting on the frame;

a hook adapted to ride passed or to clear an element of one of the containers and to engage with an internal surface of the element not facing the frame to secure the load of containers against forward movement away from the frame, the hook adapted to operate in combination with the base support by extending past the container element to retain same behind the hook and the base support vertically holding the base of the lowermost container to secure the stack of containers, the hookmanipulatable by the operator to release the container element and the container load.

The retaining member, such as a hook, may ride over or under the container element. The element may be upper element of the container, for example, above the centre of gravity of the container.

The wheelbase may include a front set of multiple directional wheels. The wheelbase may include a larger rear set of uni-directional wheels. Each multiple directional wheel may comprise two or more rows of peripheral rollers. The rollers may be adapted to rotate about axes normal to the main axis of the main axle and be radially spaced therefrom.

The main front and rear axles of the wheelbase may lie in a second plane that determines the plane in which the wlieelbase generally lies. The wheelbase is generally set at an angle between 50 and 60 degrees relative to the first plane of the frame, so that the frame angle to the vertical when the handtmck rests in the self supporting position is about 30 to 40, and preferably 32 degrees.. The angle may be determined by the likely location of the centre of mass of the load. This may be to ensure that the centre of mass of the load is within the footprint of the wheelbase.

The base support may include one or more toes, feet or tynes. The toe may comprise a flat blade extending substantially normal to the first plane. The toe may include two or more blades adapted to support the base of the lowermost container. The toe may cover only a small portion of the base of the lowermost container. The toe may be a small ledge extending a small distance out from plane or line of the frame. The toe may comprise spigots adapted to engage base elements of the lowermost container close or adj acent the base of the lowermost container.

The toe may include lateral side supports to restrict the lateral movement of the load, for example, where the containers are cylindrical drums. The toe may support the lower most containers base and additional lateral guides may cradle the container against the frame.

In a particularly preferred arrangement, the toe comprises a back support and a base. The face of the back support: facing a drum is preferably marginally recessed to a radius corresponding to a drum load to permit better purchase and engagement of the handtruck with the drum load. The base and the back support are preferably set at an angle of about 90° . The base is preferably wedge shaped to assist in extending the toe under a l oad. The leading portion of the toe is preferably tapered to facilitate penetration of the toe under the load and angling of the handtruck over-centre so that the top of the load may be tipped forward to expose a gap under the front of the base of the load. The underside of the base may have formed thereon one or more lateral barb ridges that allow the toe to slide over a pallet or other supporting surface and to grip its surface, as the top of the handtruck at its handles is levered forward to tilt the load forward. The handtruck may have a frame that includes load engagement means, such as an adjustable and/or ratchet strap. However, preferably, the engagement means is a set of one or more magnets for ferris metal loads . The set of magnets may secure the load against the frameas the handtruck is tilted forward. As the handtruck, with the load, is tilted back, the load may drop onto the base. Preferably, the base is mounted on the frame with shock absorbing means to dampen the effect of the dropped down load.

The inventive arrangement may he advantageously applied to drums (e.g.20 ltr), crates or totes, where the engagement hole, rim or engagement surface of the engagement means between or at or near the top of vertically stacked items does not provide sufficient room, space or access for the lower catch(es) when stacked. Therefore, providing a side engaging catch may Still operate effectively. This can be achieved through the cam mechanism alone or the radial travel control mechanism, or a combination of these mechanisms.

In many workplaces several type of containers may be used where one or more containers and types of containers may be stacked and required to be moved at any point in time. In this instance, a vertical adjustment mechanism may be advantageously used to ensure alignment of the catch and its engaged catch point with the height of the uppermost container.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be better understood from the following non imiting description of preferred embodiments, in which:

Figure la is a perspective exploded view of a spring cam housing assembly according to one embodiment of the present invention;

Figure l b is a sectional end view of the spring cam housing shown in Figure 1 a;

Figure lc is a side elevation sectional view of the spring cam mechanism mounted to twin parallel shafts shown in Figure la;

Figures 2a-2e show, respectively, a top plan, ripper perspective, lower perspective, side elevation and sectional side elevation views of an external fixed spring return cam component according to the embodiment shown in Figures la-2;

Figures 2f-2j are respectively, top perspective, lower perspective, side elevation and sectional side elevation of an internal cam component adapted to be housed in the housing assembly shown in Figures la-2;

Figures 2k-2q are, respectively, top plan, top perspective, side elevation, sectional end elevation, sectional bottom plan, sectional side elevation and lower perspective views of one half of the housing for the spring cam mechanism shown in Figures la-2;

Figure 3 is a perspective exploded view of a spring cam and hook engaging mechanism; Figure 4 is an assembled spring cam and catch assembly similar to that shown in Figure 3;

Figure 5a is an exploded perspective view of a spring cam bo mechanism and hook mechanism according to a preferred embodiment of the invention;

Figure 5b-5f are respectively, side elevation, bottom perspective, upper perspective, top plan and end views of a backing plate for a mounting block;

Figures 5g-5i are, respectively, top plan, side elevation and lower sectional plan views of a mounting block for mounting the parallel shafts for mounting the catch spring return box to side rails;

Figures 5j-5m are, respectively, end sectional elevations of sectional views Λ, B, C and D as shown in Figure 5i;

Figures 5n and 5o are, respectively, lower perspective and upper perspective views of the mounting block shown in Figures 5g-5i;

Figure 6a is an exploded perspective view of a rotatahle latch mechanism according to one embodiment of the present invention;

Figures 7a-7d are, respectively, perspective, end elevation, sectional end elevation of A- section shown in Figure 7c, Fig. 7c being a side elevation of a pivoting hook according to a preferred embodiment of the invention;

Figure 8 is a side view of a toe for a base for a handtruck;

Figures 8a - 8e are side, front and plan views of the toe shown in Fig. 8;

Figures 9a and 9b are perspective views of the toe shown in Figure 7;

Figure 10a is an exploded perspective view of a handtruck comprising multiple directional wheels in one of the wheel sets of the wheel base and a spring biased latch mechanism attachable to the side rails of the frame;

Figure 1 Ob is an exploded perspective view of a handtruck comprising a simple deflectable latch according to the invention;

Figure 10c is an exploded perspective view of the wheel base assembly of the handtruck shown in Figure 10a;

Figure 11 is a front elevation view of the handtruck, in assembled form, shown in Figure 1 Ob;

Figure 12 is a side elevation view of the handtruck, in assembled form, shown in Figure 1.0b;

Figure 13 is a side elevation view of a crate that is shown together with other crates in stacked formation in Fig. 12;

Figure 14 is a perspective view of a handtruck according to another embodiment;

Figure 15 is an exploded view of the handtruck shown in Fig, 14;

Figure 16 is a perspective view of a catch mechanism comprisin multiple rows of catches included in the embodiment shown in Figs. 14 - 15; Figure 17 is a perspective view of a handtruek according to another embodiment;

Figure 18 is an exploded view of the handtruek shown in Fig. 17;

Figure 19 is a perspective view of a cam mechanism comprising multiple rows of catches and included in the embodiment shown in Figs, 17— 18;

Figure 20a is a perspective view of a handtruek according to another embodiment;

Figure 20b is an exploded view of the handtruek shown in Fig, 20a;

Figure 21a is a perspective view of a cam mechanism comprising multiple rows of catches and a cable actuator mechanism included in the embodiment shown in Figs. 20a - 20b;

Figure 21b is a perspective view of the cable actuator mechanism included in the embodiment shown in Figs. 20a - 21 :

Figure 22a is a perspective view of a handtruek according to another embodiment;

Figure 22b is an exploded view of the handtruek shown in Fig. 22a;

Figure 22c is a perspective view of a cam mechanism comprising multiple rows of catches and a cable actuator mechanism included in the embodiment shown in Figs. 22a - 22b;

Figure 22d is a perspective view of the cable actuator mechanism included in the embodiment shown in Figs. 22a - 22c;

Figures 22e - 22f are side views of a catch system similar to the catch systems shown in Figs. 21 a - 2 lb and 22c - d;

Figure 23a is a perspective partial view of a single upturned catch arrangement;

Figure 23b is a perspective partial view of an upturned multiple catch arrangement;

Figure 23c is a perspective partial view of a single downwardly orientated catch arrangement;

Figure 23d is a perspective partial view of a downwardly orientated multiple catch arrangement;

Figure 24a is a perspective schematic partial view of variously orientated catches engaging or releasing from a wall panel that would form part of a container;

Figure 24b is a perspective schematic partial view of variously orientated, catches engaging crate or tote container;

Figure 25a is a schematic sectional side elevation of a toe and lower catch arrangement;

Figure 25a is a magnified view of the toe shown in Fig. 25a; and

Figures 26a - 26d are perspective views of part of a handtruek demonstrating a height adjustment mechanism that provides infinite adjustment.

DETAILED DESCRIPTION OF THE DRAWINGS

Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that tbe features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention, In the first embodiment shown in Fig. 1, the inventive device provides a spring action catch system 40 (optionally including a sprung action lever) with controlled positioning and movement range within the one simple device. It encapsulates both spring and internal cams while combining with external cams with movement range control.

Referring to Figs. 10a - 12, there is shown a frame 30, wheel base 70 and overall structure 100 for a crate carrying handtruck 100. The handtruck 100 comprises a catch arrangement 40, and the wheel base 70, similar to that described in US patent publication No. 2010140888, the entire contents of which are herein incorporated by reference.

The frame 30 preferably includes an Aluminium (Aluminum) or other light alloy frame 30 comprising side rails 31 a,b with three lateral bars 32a-c extending therebetween at vertically spaced positions, includin an upper bar 32a, an intermediate bar 32b and a lower bar 32c. At the base 33 of the frame, a toe bar 34 extends between the lower ends of the side rails 31a-b. The toe bar 34 is adapted to support an edge of a base of a crate 111 as described below.

With regard to the shape and configuration of a drum load support or toe 34, the use of tines to engage under a drum rim and on either side of the drum has been described for the handling of large or single drums (e.g. 200 Litre or single drums). In a preferred embodiment, the catch arrangement 40 may be engaged with the drum upper rim so that the drum is pulled back onto its rim at the rear, allowing downwardly angled tines to be rolled or pushed forward under the lower rim on either side. This action is fairly Simultaneous and quite efficient. This arrangement also works well on smaller drums of single unit loads. However, for stacked loads, on attempting to load a stack of drums onto a hand or motorised transport device such as a truck, the upper drum tends to pull back while the bottom drum remains flat on the floor, pallet or ground. To engage multiple stacked drum loads one must use the truck to push and tilt the stack forward opening up the lower rear rim for insertion of the tines thereunder so that the tines can engage under the rim at each side or closest to the truck.

However, hi some transport devices, the tines are angled downwards so that they tend to be scraped or pushed across the floor. Accordingly, the tines may be configured to be more horizontal to allow the front wheels of the truck to maintain contact with the floor and to roll forward. To be able to efficiently handle both single and multiple drums stacks on the one handtruck it is necessary to use a hinged toe that has a neutral or resting position in the downward angle, and be able to articulate (hinge, sprung or otherwise) to the horizontal as the frame is rotated forward. In a further iteration, the toe 34 could be locked in either position to better facilitate unloading or loading of pallets.

In Figs. 8, and 8a ~ 8e, a particularly preferred embodiment of a toe 340 for supporting a drum (not shown) is shown. The toe 340 comprises a back support 350 and a base 360. The frame 30 comprises side rails 51 and side brackets 3 1 to secure the toe 340 to the frame 30 by bolts 352. The frame 30 comprises magnets 353 facing the drum to be received to magnetically attract the drum into adjacency against the frame 30 in a loading phase. The back support 350 has a face facing a drum which preferably has a horizontal recess defined by thinked lateral wall areas 355,356 that provide rigidity for the mounting of the toe 340 by bolts or other fasteners to the frame 30.

The base 360 and the back support 350 are preferably set at an angle of about 90". The base 360 is preferably wedge shaped to assist in extending the toe 340 under a load. The leading portion 361 of the toe is preferably tapered with its upper surface marginally angled downwardly relative to the substantially horizontal plane in which the remainder of the upper base 360 surface lies to facilitate penetration of the leading portion 361 under the load. The underside surface 363 of the base 360 is angled upward towards a front narrow edge 36, whilst the base 360 top surface 365 includes a downwardly sloped surface 366. The web shaped base 360 enables a handtruck 100 to which the toe 340 is fitted to achieved optimal tilting about its wheel base 70 in a forward and downward rotation to an angle 0 of a magnitude of about 5 - 10", and preferabl about 6 ^° , relative to the floor or ground. The pivotal point P of of rotation is optimally governed by the radius R of the main standard wheel 3 about which the handtruck 100 pivots (see Fig. 10b). This enables angling of the handtruck over-centre so that the top of the load (before it has been mounted onto the toe 340 of the: handtruck 100) may be tipped forward to expose gap under the front of the base of the load.

The underside 363 of the base 360 may have formed thereon one or more lateral barb ridges 367 that allow the toe 340 to slide over a pallet or other supporting surface and to grip its surface, as the top 30 of the handtruck 100 at its handles is levered forward to tilt the load toward,

The handtruck frame 30 includes load engagement means, in this case a set of magnets position strategically at spaced vertical and lateral points on the back support 350 and the frame 30. The set of magnets 353 is clearly suitable only for for fcrris metal loads. Non-ferris metal loads may be secured by a ratchet buckle and strap in the customary manner. The set of magnets 353 may secure the load against the frame as the handtruck 100 is tilted forward. As the handtruck 100, with the load now position in a footprint over the base 360, is tilted back, the load may drop onto the base 360. Preferably, the toe 340 is mounted on the frame 30 with shock absorbing means to dampen the effect of the dropped down load. To release and unload the load a mechanical or electromagnetic separator device is employed to separate the load from the magnetic engagement with the magnet 3 3.

As best shown in Fig. 8e, the leading portion 361 comprises a central recessed region 368 to facilitae centring of the drum load and allow a wide contact area of the leading portion 361 to penetrate and to permit better purchase and engagement of the handtruck 100 with the drum load under the dram on initial tilting prior to loading.

Referring to Figs, la— lc and 3 to 4, there is shown a part of the catch mechanism 1, illustrating the way that a spring cam box 6 is mounted to a pair of parallel shafts lOa-b, a pair of retaining members in the form of catches 41 ,42 being mounted onto the upper shaft 10a as illustrated in Figs 6a and 6b.

The spring cam box 6 is preferably made of nylon or any suitable plastic or metal material and may be moulded or cast in manufacture, The: spring cam box 6 comprises a housing formed by two mirror image half components 12, 13. Each housing component 12, 13 includes three horizontal and substantially cylindrical through-chambers 121a,b,c. The uppermost chamber 121a of each half 12,13 is a large travel chamber and is adapted to receive, in axial alignment, a pair of cam members, including a first outer cam or cam member 15 and a slider or second inner cam component 14, an axial spring 16 and a section of the shaft 10a,

The two half housing components 12,13 neatly attach together by the insertion of standard bolt 18, washer 11 and hex nut 19, The bolt 18 is inserted through the counter- bored chamber 12lb. The lower shaft 10b extends through the lower chamber 121c and is fixed to the side rails 31 a,b of the frame 30 by engagement to a mounting bracket 2, as shown in Figure 5a, to prevent the spring cam box 6 from rotating relative to the frame 30.

The single axial compression spring 16 is placed over the aperturcd shaft 10a between the most central of a plurality of transverse shaft apertures 4a. The pair of inner cam components 14 each comprise internal cylindrical recesses 161 that are adapted to receive the ends of the spring 16. The inner cam components 14 slide reciprocally and axially within the large chamber 121 a and are able to rotate about the shaft 10a.

However, the inner cam components 14 are radially keyed with longitudinally aligned radial keys 1 2 that are received within and travel reciprocally along longitudinally formed grooves 122 formed in the walls of the chamber 121a, The housing 6 is therefore not rotatable relative to the cam member 14, but rather stays fixed. By contrast, the cam members 15 and the shaft 10a fixed thereto rotate relative to the housing 6.

The opposed pair of half housing components 12,1.3 are slid onto the shafts 10a,b and encase the inner cam components 14 either side of the spring 16, The spring 16 is axially compressed therebetween, noting that, with reference to Figure lc, the inner cam components 14 have axial space within the travel chamber 121a to travel toward or away from the centre of the housing 6, with the spring 16 urging the inner cam components 14 apart. .

Half of the cam mechanism 1 , each half comprising an inner cam component 131 and an outer cam 132, can be used in a similar fashion on one side or each side of the frame.30. The housing 6 can be mounted, on to a support bracket 2 and affixed to a variety of different types of supports such as handtruck frame rails 13 la,b.

Λ remote end of each catch 41a,b may be joined by a a handle shaft 7.

On to ile ends of the shaft 10a are placed the pair of outer cam members 15 having internal cam surfaces 1,30 that are adapted to bear against the external facing cam surfaces 131 of the inner cam components 14. The outer cam members 15 are seated partially within the chamber Ola in a counterborc and in an external annular flange 132 that rests against an outer rim 123 of the upper chamber 121a. Formed in the external flange 132 is a transverse groove 133 that receives a roll pin 4 that is trapped in the groove 133 and the aperture 4a to lock the outer cam member 15 against rotation relative to the shaft 10a, Consequently, the outer cam member 15 rotates with the shaft 10a,

Referring to Figures 2a-2e, there is shown in detail the outer cam member 15. To receive the shaft 10a, the cam member 15 has a central bore 134 that is adapted to co- axialiy receive the shaft 10a as a snug fit with minimal play. Referring to Figure 2d, the transition from the external flange 132 to a counter sunk, partially cylindrical wall 135 includes a step or shoulder 136 that rests against the outer rim 123 of the housing 6. The partially cylindrical wall 135 is adapted to nestle snugly in a counter-bore 124 at each outer end of the chamber 121a and ensures that the cam surface 130 remains coaxially aligned, despite transverse or torsional forces at work as the respective cam surfaces 130, 31 ride over each other. Accordingly, combined with the snug-fit of the axial bore 134 on the shaft 10a and the partially cylindrical all 135 in the counter-bore 124, the cam member 15 is extremely axially stable whereby to maintain consistent axial alignment. Thus the cam mechanism 1 is robust and resistant to torsional forces, maintaining coaxial alignment and therefore resi sting the knocking of the catches 41a-b out of alignment or registration. The securing of heavy loads, such as crates 111 full of product, can be successfully managed and the catches kept in alignment on the shaft 10a.

The cam surface 130 comprises a pair of shallow ridges 137, circumferentially interposed by a pair of diametrically opposed valleys or troughs 138 , Combined with the cams surfaces 131 of the inner cam components 14, the ridges 137 represent an unstable transition state between the engaged and the disengaged positions of the catch 41 a-42b, whereas the troughs 138 rq>rcsent the stable locked positions in either the engaged or the disengaged position when the spring 16 is least compressed and the respective centre points 151 , 152 of the outer cam member 15 and the inner cam components 14 of each pair of cam members 14,15 are closest together. A pair of gaps 150a,b in the cylindrical wall 135 cooperate with a lug or key 126 in housing counter bore 124. The gaps 150a,b limit the range of rotational travel and the pivotal range of the catches 41 a,41b as well as the rotation of the shaft 10a. The gaps 150a.b span arcs extending about 50° around the periphery between the wall 135 arc segments. The resultant extent of travel of the catch 41a,b is. about 30'. The catches 41 a,b are preloaded at about 5 degrees and unloaded in the up (or down when reversed) position. This embodiment therefore has a total rotational limited travel range of about 30 degrees (5 ^° + 25 ^° ).

The inner cam component 14 comprises a main cylindrical body 140 that rests snugly in a counter sunk cylindrical bore 125 formed internally in the upper chamber 121 a, so that the inner cam component 14 is able to travel axially along the counter-bore 125, prevented from rotation relative to the housing 6 by the operation of the combination of the keys 162 and grooves 122 and permitted to rotate relative to the shaft 10a. The shaft 10a extends co-axially through a central bore 166 formed through the longitudinal axis of the main body 140. The cam surfaces 131 of the inner cam component 14 comprise a pair of diagonally opposed tall ridges 167 that are circumferentially interposed by diagonally opposed troughs 168. The troughs 168 transition into a narrow shoulder 169 extending annularly around the upper rim of the main body 140, The cam surfaces 130, 131 are abutted in their lowest energy state with the ridges 137 of the external cam member 15 resting in the troughs 168 of the inner cam component 14. and the ridges 167 ofthe inner cam component 14 resting in the valleys 138 ofthe outer cam member 15, so that the respective shoulders 136, 169 arc adjacent or abutted, with the respective centre points 151 , 152 positioned as close as possible.

One ofthe benefits of the present invention is the flexibility to be able to readily design and interchange different cam faces 130,13 l and travel control recesses 150a,b in the housing 6. These can be combined in a variety of different iterations to achieve the required catch 41a,b positioning and spring 16 return functions for particular applications, the described cam surfaces and travel control recesses being exemplary. With reference to Figures 2k-2q, the component parts 12, 13 of the housing 6 are shown, in detail. The facing rims 170 include correspondin ; pronounced peripheral ribs 171 and corresponding peripheral recesses 172 to ensure easy registration, of the component parts 12,13 when assembling the housing 6. This allows the use of two identical half housing parts 12,13 to form the housing 6. Clearly, the skilled person will appreciate that the housing could be made with two asymmetrical parts.

In Figures 5a~5e, there is shown a support bracket or backing plate 3 that is adapted to be mounted on the side rails 3 la,3 lb, having a deflectable tab 3a that optionally permits the support bracket 3 to be disengaged from the side rail 31 a,3 lb to enable height adjustment of the assembly 40 relative to a container 1 1 3, so that the assembly 40 can be adjusted to secure different sized containers 1 11 . The support bracket 3 includes outwardly extending teeth 174 that are adapted to be captively received within corresponding slots 175 in a mounting bracket 2 shown with reference to Figures 5 - 5m, the slots 175 adapted, to receive a plurality of deflectable prongs, preferably four deflectable teeth 174, the teeth 174 having terminal barbs 1 6 that are adapted to be caught at shoulders 177 in the respective slots 175, as best seen in Figure 5k. The mounting bracket 2 comprises a pair of upper and lower bores 178a,b that are adapted to respectively receive the ends of the shafts I0a,b.

The method of installing the backing plate 3 in the catch assembly 41 is shown in Fig. 5a. The backing plate 3 engages with the mounting bracket 2 to minimise sideways play of the shafts 10a and to stop them from rattling, hanging and in the case of the height adjustable arrangements, scraping against side rails 31 a,b. The deflectable tabs 174 provide constant engagement with mounting bracket 2 so that it moves with it. The sloped tooth or engagement end (clip end) 176 is sloped or ramped 174a to allow it to move away under load from the shafts 10a,b but not to disengage due to the limit of room between the race of the rail 31 a.b whereby backing plate 3 will hit the rail 31 a,b prior to full disengagement.

The mounting bracket or block 2 provides the structural support for the cam mechanism 1. The backing plate 3 is adapted to stop the metal shafts 10a,b from rattling against the supporting frame member 31a.b and to prevent the shafts 10a,b from interfering with the face of the rails 31 a,b in an embodiment where the cam mechanism 1 is height- adjustable and/or vertically siidable relative to the rails 3 la,b. As the backing plate 3 is spaced from the back wall of the support frame 30 slightly, tlie barbed heads of the deflectable tabs 3 a are ramped slightly to allow the backing plate 3 to move slightly without disengaging as they would otherwise need to allow over-travel and are permitted to be a little loose. In Fig. 3, the assembly 40 is shown with a height adjustment device 180 that represents a number of different releasable fixing means to enable the assembly 40 to be moved up and down the rails 3 la,b. The height adjustment device 180 may include a biased plunge bolt that enables the assembly 40 to be adjustably mounted to the side rails. The plunge bolt head may be encased in a knob handle 181. To provide an adjustable height locating system, one option providing a number of fixed or defined locations is shown in Fig.3 where the bolt shaft preferably bears against one of the side rail 31 a,b. to lock the assembly into one of a range of height positions on the rails 31 a,b. The handle 181 is mounted on. an L-shaped bracket 1 82 that receives each of the shafts 10a,b and the mounting block 3 to provide a movable carriage therefor up or down the rails 31a,b, as required. The skilled person will appreciate that other height adjustment mechanisms may be employed to move the assembly up and down the rails 3 ta,b to suit various sized containers 1 1 1. Other options for an adjustable height locating system are described with reference to Figs. 4 and 14 - 24b.

There are numerous methods for mechanically releasing and securing the mounting block 2 and bracket 3 in position on the rail 31a,b. There may be considered two scenarios:

a) Where there are a number of predefined positions such as for a handtruck adapted to carry various specific sized containers 1 11. In such an arrangement, sprung plunge type fixing such as a plunge bolt may be adapted to cooperate with predrilled holes. The plunge bolt may be fixed to the moveable assembly with holes in the support frame 30 in, for example, either the rear face or side of the rail 3 l a,b. Alternatively, the mounting block 2 may be fixed so as to be static on the frame 30 with the block 2 predrilled and fixed in position to the moveable catch assembly,

b) Where random and variable positioning is required to secure loads of container sizes requiring a large range of finely separated incremental positions, one solution is to use two abutting and releasable saw tooth or serrated plates. At least one plate may be elongate to cover the range of position adjustments required. One of the serrated face plates may be attached to the frame and the other to the moveable assembly. A spring mechanism preferably biases the facing serrated plates towards each other to keep them together in the selected position. A handle or pull knob may be used to allow the plates to be separated and moved relative to each other to move the catch assembly to a different position. As the assembly 1 is snugly contained in the support rails 31 a,b the facing plates only have to provide vertical positioning. Reverse saw tooth engagement surfaces may provide advantageous protection against separation of the plates under load in the downward direction. Referring to Figure 5a. it can be seen how the assembly 41 fits together to achieve a pair of deflectable catches 41a,b.

Referring to Figs, lOa - 10b, the catch arrangement 40 includes one or more sets of catches 41,42, each set comprising one or more (preferably two) catches 41 ,42.

However, it will be appreciated that in some applications, the catch arrangement 40 may comprise only one catch 4 land that may be satisfactory or desirable. The sets of catches 41,42 comprise an upper set of catches 41 a,b and a lower set of catches 42a,b. Each set of catches 41 ,42, is pivoted about a horizontal axle 43a,b. Each catch 41a-42b comprises a broad and solid main body 44 defined by a pair of side walls 46 substantially lying in parallel planes spaced by a contoured wall 47. The body 44 tapers rearwardly to a second or remote end that is a radiused or rounded rear end 45. The radiused end 45 of each catch 41a-42b has a rear aperture 45a to receive a rear catch axle 48 that acts as a handte for releasing the catches 41 a-42b. The handle 48 is pulled up or pushed down, depending on catch orientation, by an operator, to release the catches 41a-42b from the load items 1 1 1. The handle 48 visually assists the operator to ensure that the catches 41a-42b are correctly oriented. The radiused end 45 of each member of the lower set of catches 42 to move together, and the radiused end 45 of each member of the upper catches 41 to move together. The broad central portion 49 of each catch 41a-42b includes a central aperture 49a that receives the central horizontal axle 43a,b about which the catches 41 -42b rotate.

The central axles 43a,b extend through the central apertures 49a and are journaled for rotation in journal or mounting brackets 2,50 mounted on the inside faces 51 of the side rails 31a,b. The journal brackets 50 are preferably mounted together with a mounting plate 3that is sliable up and down the side rails 3 la,b by various friction or positive clamp and release mechanisms, such as grub screws, threaded axially displaceable hand- operated knobs, spring loaded plunge bolts, rack and pinion mechanisms, deflectable tabs 3a, or dual spring loaded plates with mating profiles, and the like.

The journal brackets 50 may have a rocking arrangement comprising a butterfly groove/cam 91 located in the rear of each bracket 50 in which a roll pin travels reciprocally through a limited arcuate pathway defined by the butterfly groove. The roll pin 92 can rotate about the axles 43a,b, but the amount of travel is limited. This may restrict the rotation of the catches l,41a-42b within a certain limit and may act as a fail safe should the container load bounce or be moved off the toe/nose 34, therefore providing support of the load in an emergency. It may also restrict the upward travel of the catches 41 a - 42b to keep them positioned to allow them to properly engage and not run into the back of an engaged container or the bottom of the container above the catch l ,41 a-42b. However, an improved means of controlling the rotational travel of the axles 10a, 43a,43b is described with reference to the earn mechanism 6 inter alia shown in Figs, la - 5a.

Extending vertically between the upper and lower sets of the catches 41 a-42b is a control rod 60 that causes the upper and lower sets of catches 41-42 to rotate about their respective central axles 43a,b together. The control rod 60 is rotatably mounted at each end to respective upper and lower vertically in-line catches 41b, 42b main bodies 44 by bolt means 61 extending through an eyelet 62 at each end of the rod 60 in to an aperture 49b in the main body 44. More than one control rod 60 might be incorporated in the arrangement, for example to control sets of catches adapted to fit different sized staekable containers.

The orientation of the mounting block 2 can be varied to accommodate different mounting constraints with regard to the positioning of the side rails 31 ,b and the engagement elementl 15 of the load. Mounting screws may be used to mount the mounting block 2 to the rails 1a,b in defined locations according to pre-formed apertures 205 (see Fig. 19a) in the rails 31a,b.

As best shown in Figs. 7a - 7d. extending forward from the main body 44 of each catch 41a-42b is an arm 54 with a linear underside wall 52 terminating in an upwardl extending hook 55 , The parts of the contoured wall 47 of the main body 44 and the inside surface 56 of the hook 55 facing each other, together with the inside wall 57 of the arm 54 continuous therewith, define a recess 58.

In Fig, 10a, the toe 34 is shown mounted to the rails 3 la,b. The rails 31 a,b are for a handtruek that is typical of a modular aluminium handtruck/trollcy but with a narrow toe 34 according to one embodiment of the invention.

With reference to Fig. 12, the recess 58 of the catch 41 ,42 is adapted to receive an engagement means or element 1 14 of a container such as a crate container 1 1 1. The container 11 1 may be any sort of container wdth a suitable engageable element 114. Preferably, a plurality of like containers l l la-c are staekable as shown in Fig. 12d. The container 1 11 may be a milk crate formed of a molded lattice or grid of bars and beams, whereby one of the bars or beams performs as the element 114. The container 111 is preferably of reproducible, consistent and predictable shape. The element 1 14 may comprise a tab or a bar 115 extending horizontally across an upper portion of the container 11 1. A recessed or hollow portion 1 16 may permit one of the upwardly turned hooks 55 to extend through the portion 116 so that the bar 1 15 engages with or is retained within the hook's catchment area 59.

As shown in Fig, 4, there is shown a preferred catch system including another option for the height adjustment mechanism comprising a plunge bolt arrangement similar to that described with reference to Figs. 20a - 22d. The rear axle 48 of the upper set of catches 41 is concentrically covered by a broad sleeve forming a handle bar 53 for an operator to control the pivoting of the catches 41a-42b. The handle bar 53 is mechanically connected to the remainder of the catch arrangement 40 by the rod 60, whereby upward pressure on the handle bar 53 causes the upper catches 41 to rotate about the upper axle 43a and, through the operation of the rod 60, the lower catches 42, so that the hooks 55 move downwardly to a disengaged position to enable the hook 55 to travel into the hollow portion 1 16. As a fall back provision, the handle bar 53 may be released or pushed downward to its original bar 116 engaging position in which the linear surface 52 is substantially horizontal, should the following described automatic engagement fail for any reason, for example because of misalignment or spring 16 pressure.

The pressure on the nose of the catch 1 from the crate 111 causes it to move out of the way as it i pushed into the engagement opening 116 and it then springs back up (or down, a the case may be), securing the crate 1 11 to the handtruck. The relationshi of the connection of the catch 1 to the first shaft 10a that provides the pivot point 45a for the catch 1 relative to the position of the hook 55 or recess 59 provides mechanical synergy in the securement of the load item 111 or bar 115 to the catch 1.

As the engagement means is received in the recess 59, pressure is applied to the inside face 56 of the hook 55 and the engagement means pulls into the inside hook surface 56, rather than away, thereby reducing the risk of the catch 1 disengaging under load. To disengage the hooks 1 it is then necessary to manually pull the handle 48 upward (or push downward in a reverse fitting in which the hook 55 points downwards) to disengage the catches 1, thereby using the handle 48 to simultaneous retract the handtruck 100 from the load stack 1 1 la-c.

In the engaged position, the hooks 55 trap the bar 15 in the catchment area 59 so that the crate 11 1 is locked in place on the handtruck 100. The hook 55 comprises a forward face 55a that presents are ramped, cammed or convex surface tapering upwardly to a tip 55b that assists in allowing the hook 55 to deflect past a lower edge of the bar 115 and through the hollow portion 116.

As shown in Figs. 10a - 1 Oe, the wheel base 70 comprises a rear set of standard, large diameter directional wheels 71 mounted to the wheel base 70 by a first set of elongate brackets 173 that has apertures that arejournaled to receive a main standard axle 81 and a front axle 76 and curved side edges along its intermediate beam to save weight and materials, whilst each end has first and second broad head 178,177 to respectively attach the front axle 76 and inter alia the rear axle 81. The underside curve of the brackets 173 allows better engagement of front wheels 25 on an upper surface when traversing a kerb or getting onto or off a pallet, by allowing better clearance of the bracket 173 passed the kerb, etc.

A second L shaped set of brackets 72 having a pair of arms 73a is attached to and extends from the first head 178 to welded or bolted spaced mounting brackets 74a,b on the side rails 31 a,b. The wheelbase 70 further includes a front set of multiple directional wheels 80 mounted on a front wheel axle 76 joumaled for rotation in the lower mounting brackets 173. The front wheel axle 76 extends adjacent and rearward of the side rails 3 la,b. Alternatively, the rear wheel set may be of the multiple directional type and the front set of wheels may be standard wheels or also of the multiple directional type. The multiple directional wheels 80 are of the type supp lied by the applicant, Rotacaster Wheel Limited, and are described in International publication Nos. WO0224471 and WO2004014667, the entire contents of which are herein incorporated by reference.

The broad head 177 of the bracket 173 fixes the wheel base 70 relati ve to the side rails 31a,b. Although the upper brackets are attached to the second head 178 by a single bolt, 179, the upper brackets 72 are not pivotable but fixed to the side rails 31 a,b at a position on the side rails 31 a,b higher up the rails 31 a,b and act as braces to support the load 112 of the handtruck 100 bearing on the side rails 31a,b.

Referring to Figs. l ^' Qa - 12, extending forward of the side rails 3 1 a,b and the front wheel mounts 74b is the toe bar 34 which is mounted by bolts or welded to the side rails 3 la,b. The toe bar 34 provides a shallow ledge 35 on which the base 117 of the container 111 may rest. In operation, the handtruck 100 is pushed with a load of up to one to five stacked crates 1 12, oriented so that the frame 30 is substantially vertical as shown in Fig. 12d, nudged so that the toe bar 34 slides in underneath the bottommost crate 11 lc. There is a section of this that shows some serrations 38 (see Fig. 25b) to provide better grip on the edge of a pallet when unloading or loading.

With reference to Fig. 3, the catch arrangement 40 is moved to a disengaging position by lifting the handle bar 53 so that the hooks 55 of the catches 41 a-42b can be slid in under the container elements 15 of the lowest 111 c and third lowest 111 a crates 1 11 whereby to lock same 1 11 into an engaged position on the handtruck 100 by the handle bar 53 moving downwardly to the engaged position shown in Fig, 12. The catches 41a move automatically which is the purpose of the cam/spring box 6 design. Correctly setup and positioned, the catches 41a should only need to be disengaged manually by raising or pulling u on the handle 48 as engagement should be automatic. As discussed below, the cam spring device 6 may provide a bias towards and to the closed or locked position so that the operator need only lift the handle 53 to the disengaged position, the spring cam device 6 urging the catches 41 back to the closed position when the hooks 55 have cleared the lower edge of the bar 115.

The catches 41 -42b can also be deflected to the disengaged or an open, deflected position by simply applying pressure through the frame 30 to catches 41 and hence to the leading cam surface 55a that abut against the bar elements 15 of the containers l l la,c in the stack 1 12.

With reference to Fig. la lc, and 5a and 6, the catches 41a-b may be retained in the engaged position in which, the linear surface 52 is substantially horizontal. The resultant extent of travel of the catch 41a,b is about 30°, governed by the key 126 trapped in one of the gaps 150a,b. The catches 41 a,b are preloaded at about 5 degrees and unloaded in the up (or down when reversed) position. This embodiment therefore has a total rotational limited travel range of about 30 degrees (5 ^° + 25") The catches 41 a-b may be biased to the engaged position by a spring 16 contained in a spring cam box housing 6. Against the force of the spring 16, the catches 41 a-b are deflected by the container element such as the crate beam 1 5 and the hooks 41 a-b move down under the opening 116 below the container element 1 15. Through the transition from the closed to the ope positions, a pair of qiposed cam membersl4, 15 axialiy aligned and having opposed cam surfaces, ride one against the other to lock into an open position. To move the catches41a-b back to a closed position, the direction of rotation of the hooks 55 is reversed and the hooks 55 are rotated in the direction that the spring 16 force urges, the cam surfaces of cam elements 14,15 riding one against the other back over a cam ridge or ridges for the catches 41 a-b to engage the element 115.

The embodiment shown in Fig. 6 may be used with either an independent spring bias mechanism 249 such as that shown in Figs. 14 - 16, or a remote spring/bias mechanism 6 such as that shown in Figs. 21 a - 21c. A roll pin 4 can be used at the end of the shaft 10a using the butterfly recess 175b shown in Fig. 5i to restrict rotation of the shaft 10a to a limited range, or a remote travel control employing a combination of ga 150a,b and lug 126 of the cam/spring box 6 may be used.

There may therefore be no the need for the operator to activate handle 53 to engage the element 1 15. However, the handle 53 will need to be activated to release the container 1 1 1 ready for unloading from the handtruek 100. The frame 30 may then be tipped to an angled orientation of, say about 30 to 45 degrees, depending on the centre of mass of the load 1 12 so that the wheel basc 70 lies flat on the ground and the handtruek 10 is self- supporting with all four wheels 71,80 in ground contact, The angle of the frame 30 at rest may, for example for a milk crate track, be fixed at about 32 degrees, or may be adjustable to accommodate different angles. In providing a self-supporting handtruck 100 of very light construction, with minimalist load 1 12 support structures such as the toe bar 34, and with the versatility and manoeuvrability of a truck with a front set of multiple directional wheels 80, the handtruck 100 provides a dramatic improvement in materials handling equipment to reduce operator strain and injury, and increase productivity. The other advantage of the 4 wheeled wheel base 70 with a front and a rcarset of wheels 70,80 is it allows the truck 100 to be levered off the back or the front wheels 70,80 which allows the handtruck 100 to negotiate, step over or clear obstructions, for example on and off pallets or up a single step or change of level with relative ease, both with and without a load 112.

The orientation of the catches 41 a-b may be flipped upside down to engage with other shaped containers having an upwardly extending lip, such as is found in cylindrical drums, such as 20L drums.

Referring to Figs. 14 - 16, there is shown a crate carrying handtruck 200 similar to that shown in Figs. 10 - 1 1 and demonstrates a simple embodiment using a single externally mounted spring 249 in lieu of the spring earn box 6 and is not height adjustable. . The handtruck 200 has a catch mechanism comprising an upper row 241 and a lower row 242 operably joined by a rod 260. so that the rotation of the upper row of catches 241 is coupled to the rotation of the lower row of catches 242, in terms of extent and direction. Each end of each first shaft 210a of each row 241 ,242 is mounted to the side rails 231a,b by a mounting block 202 and bracket 203 (similar in structure and function to the mounting block 2and bracket 3) which is attached to the rail 231 a,b at a required height by a bolt 208 that extends through an aperture 205 in the side of the rails 2 1a,b and is threadably received in a hex nut residing in a central bore 204 in the mounting block 202 and bracket 203. By providing multiple spaced apertures 205 along the length of the rail 231a,b, the height of the upper and lower rows 241,242 might be adjusted to suit crates or other containers having different dimensions and engagement features or means, but this arrangement is primarily a static model with fixed row positions. To be height adjustable, it would require the rod 260 to be lengthened or shortened as appropriate and the following embodiment shown in Figs 20a-d and 22a-d using a cable 460,560 addresses the need for a flexible multiple row control means.

The rows 241,242 include a handle 248 that is rotatable upwardly against the bias of a spring 249 that is attached to the lower one of the catches 41 a at or near the handle 248 end 245 in an aperture 244 (see Fig. 6e) and extends to a mounting point on the frame 230. the catches 41a are prevented from rotating so that the handle 248 travels only down to a level in which the catches 6 are substantially horizontal by means of a detent in the aperture 49a (see Fig. 6c) or on the frame 230. In this way, the hook 55 of the catch 6 can deflect downwardly to receive engagement means 1 15, but cannot deflect upwardly. In this embodiment , bias is provided by an external spring 249 at the base of the frame 30. Rotation and travel control is effected by the roll pin 4 extending through the end of (he axle shaft 10a and located in the butterfly openin 175b in back or rail side of the m ounting block 2.

Figures 17 - 19 illustrate a handtruck 300 similar to the handtruck 200, but instead of the spring 249 effectin bias on the catch rows 341,342. the handtruck 300 includes a spring cam mechanism 6 that provides the rotation limiter and bias required for the control of the movement of the catches 41a. This embodiment uses a single spring cam unit 6 to provide spring bias 16 and radial travel range 1503,^126 and positioning of the catches 41 . It uses a tie rod 60 to transfer/control the rotation and operation of one or more subsequent rows of catches 42. It is used where vertical positioning of rows 41,42 is fixed or static.

Figs. 20a - 21b show a handtruck 400 similar to the handtruck 300, but includes an enhanced height adjustment mechanism 480 and a sheathed cable 460 similar to a brake or gear cable that is commonly used for bicycles. This embodiment utilises the spring/cam unit 6 to allow one or more rows 441,442 to be adjustable/relocated vertically to cater to different sized crates 1 ll a-e. Each adjustable row 441,442 should have its own spring/cam unit 6, and at least one of an array of statically located rows 441,442 must have a spring/cam box 6, (or a separate bias 249 as shown in Figs. 14 - 16). Subsequent static rows can be linked by a tie rod 60.

The height adjustment mechanism 480 comprises a sprun plunge bolt having a knob handle 481 that provides a quick and convenient release means attached by the bolt bearing on a front flange wall of the rails 431 a,b. The height adjustment mechanism 480 includes an L-shaped bracket 482 that carries the catch mechanisms 441,442 and the height adjustment mechanism 480, so that the catch mechanisms 441 ,442 can be height adjusted in an unlimited range of positions along the length of the rails 431 a,b.

The rotational movement of the upper and lower catch rows 441 ,442 are coupled by the sheathed cable 460, so that if the upper or lower handle 448 is lifted, the other handle is caused to lift as well by the operation of the cable 460. The respective ends of the cable are mounted by rigid steel, aluminium or plastic brackets 461 against the internal face 179 (see Fig. 5o) of the mounting block 2 and held firm against rotation by receiving both the upper and lower shafts 10,b through corresponding apertures 462. The respective ends of the cable 460 are fixed to pins 463 that are received in the apertures 49b of the catches 1. The catches 1 on each row 441,442 are moved closer together on the shafts 10a,b. The cable holder 461 fits, but can be located on the other side of the catch 441a,b, if necessary. The particular positioning of the catches and the cable holder is container-dependent, but there is flexibility of where it goes.

Figs. 22a - d shows a handtruck 500, similar to the handtruck 400, except that the toe 534 is narrower to improve manoeuvrability in tight spaces, such as between stacks of crates 111. It demonstrates a narrow isle truck 400 that can travel between stacks of crate/totes. It accommodates a single cateh 542a in the bottom row 542 and uses one half 506a of a cam/spring unit 6 modified to fit within and to the rails 53 la,b. It is an example of the flexibility and adaptability of the cam/spring unit 6.

The toe 534 is a L-shaped plate mounted to a telescopic rack 580 comprising a pair of stationary rails 581 attached by bolts, rivets or welding to the inner walls of side rails 53 la,b via intermediate spacers 583. The lower part of the rack 580 includes slidable rails 584 carrying the toe 534. The slidable rails arc height adjustable along the racks 580 by means such as pin or bolt and aperture combinations,

.Referring to Figs. 22e - f, the operation of the cable system 460 (and 560 in Figs. 22a - d) is shown in more detail, with the top catch row 441 shown in Fig. 22e and the lower catch row 442 shown in Fig. 22f. The wire cable 464 is attached at either end to the cable aperture 49b . Each of the catches 441b-442b are pivotally mounted to a shaft 10a through its aperture 49a. The cable sheath 465 is fixed at each end to the cable mounting bracket 461 (in turn fixed to the frame 30), so that the effect oF the axial movement of the cable in the sheath 465 cable 460 is to coordinal and synchronise the rotation of the respect catches 441 b,442b.

Figs. 23a d illustrate a variety of different positions and orientations that the catch 1 may be placed in to suit different applications. For example, many European crates and many totes have a single centred opening (lifting point or engagement element or bar 115) rather than a pair of spaced access points. This is likely to be common. Milk crates mostly have two, but not always and bread crates require more than one due to the width and flexibilit of the engaged edge.

Fig. 23a shows that a single catch 1 may be adequate in certain situations, such as where stable and rigid loads are involved or the catch is used to secure an engagement means associated with, a gate or other closure. Fig. 23b is similar to arrangements found in various embodiments of the handtruck 100, 200, 300 and Figs. 23c and 23d show the orientation of the catches 1 when an upward deflection of the hook 55 is required to engage the engagement means.

Fig. 24a shows how the catch 1 can engage a side panel or wall of a load item 1 1 Id by deflecting the hook 655 upwardly in directio D, or laterally by orienting the catch mechanism la on its .side. Similar orientations of the catches 1,1 a are show with respect to the sceurement of a crate 11 lc are shown in Fig 24b. Optionally, the container includes a recess 1 14 configured to register and locate the hook 55, whether the hook 55 is inserted through a hole 116 or engages from above the bar 115. Lateral securement of a load 11 lc can be enhanced by providing lateral catches l a that engage the side of a load stack 112 and engage a vertical rib on the container 11 lc. The lateral catch la orientation incorporated on a catch mechanism 41 turned on its side so that the shaft 10a is substantially vertical and suitably mounted to a handtruck or other device can be used on its own to secure a load.

With reference to Figs 25a - b, the method of engaging a tote or crate 11 lc on a handtruck 100 can be described. The handtruck 100 is tilted forward so that the handtruck 100 rides on its multidirectional wheels 26toe 34 ledge is oriented horizontally and approaching the underside edge of the crate 1 11c. On this tilled orientation, the catch hook 55 approaches the hole 1 16 in the crate 11 lc, on abutting the bar 115 deflects downwardly against the bias 249 (or if the spring cam box 6 is utilised, spring 16), and the hook 55 rides passed the bar 115 so that the lower edge of the bar 1 15 locates in the recess 59 and the catch 42a springs back to the engaged position. At this stage the crate is fully engaged by resting on the toe 34 ledge and secured by the catch's 42a hook 55. The handtruck 100 may then be pivoted backwards on to its 4 wheels 25,26 for excellent manoeuvrability in congested places and over difficult obstacles using the lateral movement capacity of the multidirectional wheels 26 and the stability of the 4-wheel base 70. This arrangement is self-supporting and enables the operator to simply push and direct the handtruck 100, rather than be required to pariially support its load 111.

The toe 34 comprises an L-shaped plate with a mounting plate 36 bolted on to a toe mounting L-shaped plate 38 that, in turn, is mounted on to the rails 31 ,b to provide a strong supporting structure.

Referring to Figs 26a - d, Fig. 26a shows a. catch assembly 600 using an independent spring 249 (not shown) in which the hooks 55 are mounted for upward deflection to engage the upper surface of an engagement element 115 (not shown). The eatch assembly 600 is so-called infinitely height adjustable in that it allows for a large number of small incremental position changes within a range defined by the length of a pair of serrated strips 90 fastened to the front panel 91 of the rails 31 a,b. The catch assembly 600 is mounted on a travelling L-shaped bracket 92 (which may be any suitable configuration, such as channel shaped or have a lateral arm extending from ) having a front plate 92a having an inside serrated surface that is adapted to cooperate with the serrations 93 on the strip 90, The travelling plate 92 is lightly biased towards the serrated strip 90 by a leaf spring 94 to which it is fastened by a screw 95 and wire loop 95a, The screw 95 is adapted to travel reciprocally in a small slot 95b formed in a side plate 96c of the travelling plate 92, to adjust the height of the assembly 600, the knob handle 97 is pulled out against the bias 94 a small distance sufficient to disengage the serrations on the strip 90 and the front plate 92a, so that the front plate 92a can be moved up or down as desired as indicated by arrows U,D in Fig. 26d. On releasing the knob 97, as shown in Fig. 26c, the front plate moves back into engagement with the strip 90. This arrangement is particularly advantageous as it is mechanically vertically capable of supporting large loads whilst only requiring a small force to pull the knob 97 out to make a height adjustment.

Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary i expressly stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

In the present specification, terms such as "component", "apparatus", ''means", "device" and "member" may refer to singular or plural items and are terms intended to refer to a set of properties, functions or characteristics performed by one or more items having one or more parts. It is envisaged that where a "component", "apparatus", "means", "device" or "member" or similar term is described as being a unitary object, then a functionally equivalent object having multiple components is considered to fall within the scope of the term, and similarly, where a "component", "apparatus", "assembly", "means", "device" or "member" is described as having multiple items, a functionally equivalent but unitary object is also considered to fall within the scope of the term, unless the contrary is expressly stated or the context requires otherwise.

Orienlational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the handles uppermost.

It will be appreciated by those skilled in the art that many modifications and variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention.