This invention relates to a trolley design for handling materials and in a particular but not exclusive aspect, relates to a trolley suitable for handling heavy drums. BACKGROUND OF THE INVENTION

Numerous trolley designs have been proposed for materials handling. Perhaps the most common of these is the simple hand trolley which consists of a carrier frame terminating at one end in a handle and at the other in a lifting shoe. The lifting shoe is generally perpendicular to the carrier frame and a pair of wheels are provided at or near the join between the carrier frame and lifting shoe in order that the trolley can be allowed to stand up right with the lifting shoe resting flat on the ground. It may be tilted from the upright position with the axle joining the wheels acting as a pivot axis about which the trolley and any object or materials held on the trolley carrier may be tilted.

Generally speaking trolleys of this design have been successfully employed in many applications. However, they do suffer from a number of deficiencies when they need to be used in specialised materials handling situations. For example, when removing heavy drums from pallets, one must work the shoe underneath the drum. The trolley is then tilted so that the drum falls back on the carrier and remains resting on a shoe. This can be very difficult when 200 litre drums containing in excess of 200 kg of material are being handled.

Once the drum has been tilted on the trolley, the trolley can be wheeled along. However, the stability of the tilt position depends on maintaining the centre of gravity of the drum immediately above the axis of the wheels of the trolley. Thus, when the trolley needs to be stepped down from a pallet, extreme caution must be exercised to maintain the drum in the correct orientation for the jump down step or disastrous consequences can result. This operation requires a considerable degree of skill and brute strength and also involves substantial risk. Unfortunately, incorrect handling can result in serious injury to the operator and/or damage to the drum and its contents.

Consequently, there is a need for an improved trolley design which facilitates the handling of large objects such as drums in difficult situations such as removal of drums from pallets. DISCLOSURE OF THE INVENTION

In one aspect the invention provides a trolley including a carrier and a first wheel means attached to the carrier said first wheel means being movable between a first and a second position with respect to the carrier, said trolley including biasing means arranged to urge said first wheel means into the first position.

The first wheel means may include a first pair of front wheels. The first pair of front wheels may be mounted on a wheel assembly. The wheel assembly may include a pair of arms. The wheel assembly may also include a front axle. The arms may be mounted on the front axle. One front wheel may be mounted on each arm. The front axle

5 may be mounted on the carrier. The wheel assembly may be pivotable with respect to the carrier. Pivoting of the wheel assembly with respect to the carrier may cause the wheel means to move between said first and second positions. Preferably the wheel assembly may pivot with respect to the front axle. Stop means are preferably provided to prevent the front wheels pivoting beyond the first or second positions.

₁₀ Movement of the wheel means between the first and second position may cause the arms to pivot with respect to the carrier. Preferably the arms are arranged so that they are held in either the first position or the second position depending on whichever is their initial position, by the weight of a drum or other heavy object held on the carrier when the trolley is laid flat to rest on the ground. _j 5 The front wheels may pivot over an arc defined by a straight line forming the radius of the arc, movable over the arc and joining each axis of each front wheel and the point about which the respective arms pivot. The arcs preferably include a position where the straight line joining the axis of the respective front wheel to the pivot point makes a right angle generally defined with respect to the carrier. Preferably the straight line

20 makes an angle of between 1 and 20°, more preferably 5 and 10° with respect to and forward of said right angle when the wheel means are in the first position.

The carrier may include a frame. It may be of generally square or rectangular configuration. It may have sides defined by a pair of parallel frame members. The parallel frame members may be joined by one or more cross members. One of the cross

2 members may form a handle for the trolley. Alternatively and/or additionally, the parallel frame members may themselves form handles for the trolley. The handles may be formed at ends of the parallel frame members.

Preferably there are at least two cross members. More preferably there are three cross members.

30 The trolley may include rotation means. The rotation means may be adapted to facilitate rotation of a circular object such as a drum, supported by the trolley. Preferably the rotation means are mounted on one or more cross members. Most preferably the rotation means are mounted on two cross members. Alternatively and/or additionally, the rotation means may be mounted on one or both of the parallel frame members.

- ₅ Preferably the rotation means include rotation wheels arranged to support a drum or other object on the carrier. The rotation wheels may be mounted to rotate with their axes generally parallel to the parallel frame members. Preferably the rotation wheels

are mounted in wheel pairs. Individual wheel pairs may be mounted for rotation on common axles. The common axles may be mounted on the cross members. Preferably two wheel pairs are mounted on each of two cross members.

The trolley preferably includes a rear wheel assembly. The rear wheel assembly may be mounted on an intermediate position on the carrier. Suitably, the rear wheel assembly includes a pair of rear wheels. The rear wheel assembly may include a rear axle joining the pair of rear wheels. It may also include mounting members. The mounting members may support the rear axle. The mounting members may be secured to the carrier. Most suitably there are two mounting members. They may be secured to the 0 parallel frame members.

Support shoe means may be provided on the trolley. They may include a pair of shoes extending from one end of the trolley. Said one end is preferably the end to which the front pair of wheels is closest. The shoes may extend or curve in a direction substantially perpendicular to the parallel frame members. They may be mounted on the 5 carrier. Preferably the shoes are mounted on respective mounting plates. The mounting plates may in turn be mounted on the parallel frame members.

Load retaining means may be provided in association with the trolley. The load retaining means may be mounted on the carrier. Preferably, the load retaining means include a pair of retainers slidably mounted on the parallel frame members. The retainers ϋ may each include a downwardly extending tongues and/or clamps adapted to fit over the lip of a drum. The retaining means may also include additional and/or alternative devices for securing a load to the trolley. For example, a strap or clamp may be used to assist with securing a load.

The trolley may include brake means. The brake means may suitably be 5 arranged to brake rotation of one or both of the first pair of front wheels. The brake means may include a brake lever. It may also include a brake cable, a brake bolt and spring means. Preferably the spring means are arranged to urge the brake bolt into braking engagement with one of the front wheels causing that wheel to act as a braking wheel. 0 The braking wheel may include engagement means for engaging the brake bolt.

The brake lever may be arranged to move the brake bolt into and out of engagement with the engagement means. The engagement means preferably include a plurality of projections extending from the side of the braking wheel. Suitably, the projections may take the form of a series of nuts and/or bolts. These may be arranged in circular fashion 5 around the braking wheel.

The biasing means may include a spring. The spring may be arranged to rotationally urge the front axle in such a fashion that the wheel means tend to assume the

first position. Preferably, the spring encircles the front axle. Any other method of pushing the axle to the first position may be used e.g. gas strut, leaf or coil spring pushing directly or indirectly on the axle or axle plate.

Preferably, the trolley is constructed in such a way that it can hold an object on the carrier in a generally horizontal position when the trolley is laid flat and the wheel means are in the first position. Thus, when the object concerned is a drum, the axis of the drum may be held substantially horizontal making it possible to rotate the drum on the rotation wheels. Rotation of the drum makes it possible to move the bung on the drum into a pouring position should this be required. Another benefit is to be able to rotate the drum into a position where leakage from a bung or damaged drum skin is avoided.

In order to facilitate handling of heavy objects such as 200 litre drums, it is preferably that the trolley be able to hold such objects both at an angle to the horizontal and also vertically ie. there should be stable rest positions in both the vertical configuration and in a configuration where the object is tilted with respect to the horizontal. Whilst a vertical position is a naturally stable position for an upright object such as a drum, such is not normally the case with a tilted configuration using conventional trolleys. By having a stable tilted position it is relatively easy to manipulate and move the drum particularly when the drum or object is to be moved from a pallet.

Applicants have found that a tilted stable rest position which holds the object at 15° to 50° to the horizontal is preferred. An inclination of 20° to 40° to the horizontal is more preferred and about 30° to the horizontal is particularly advantageous. Preferably the trolley assumes the stable lilted position when the wheel means are in the second position and the trolley has both the front and rear wheels resting on the ground.

In order to facilitate removal of objects from platforms including pallets, it is preferred that the lowermost point of an object held on the trolley in its stable tilted position be greater than the height of the platform from which the object is being removed. Thus the carrier and object can clear the platform when the object has been tilted. As pallets are typically 150 mm in height, it is preferred that the lowermost point of the carrier when the trolley is in the stable tilted position, clears the pallet and is therefore higher than 150 mm. Preferably the trolley is constructed so that the height of the lower most point is between 150 mm to 180 mm. Generally speaking a height of 155 mm to 170 mm is most preferred.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THF. DRAWINGS

FIGURE 1 is an isometric view of a trolley constructed in accordance with the invention;

FIGURE 2 is a side on elevational view of the trolley of FIGURE 1 loaded with a drum; and

FIGURE 3 is a detailed sectional view of the brake assembly of the trolley shown in FIGURES 1 and 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to Figures 1 and 2, there is shown a trolley generally designated 1 which includes a carrier 2. The carrier includes a pair of parallel frame members 3 which may suitably be of tubular steel or other strong material.

The frame members 3 terminate in handles 4. Cross members 7, 8 and 9 are IQ secured to the frame members 3 in the manner illustrated forming part of the overall carrier portion of the trolley. Cross member 7 may be shaped so that it can form a handle in addition to handles 4.

The carrier 2 includes two plates 15 which are secured to the frame members 3 at the bottom of the carrier. The plates 15 act as mounting points for the spring axle 16 _j 5 rotatably mounted thereon.

A coil spring 17 wound around the spring axle 16 is arranged to urge the front wheels 18 in a direction opposite to that shown by the arrow 20 in order that the front wheels 18 may assume the configuration shown in Figure 1.

The front wheels are mounted on the spring axle 16 by way of the arms 19. 2 Thus, the front wheels are pivotable between first and second positions with respect to the carrier.

In Figure 1, the wheels are shown as being in the first position with the sides of the arms 19 abutting against the ends of the drum locating shoes ie. the drum locating shoes limit the extent of pivoting of the front wheels with respect to the carrier in the

2 clockwise direction. The limit of this pivoting will be slightly beyond the position where the arms are perpendicular to the frame members.

Similarly, the anticlockwise pivoting of the front wheels may be limited by an abutment with the rear edge of the respective plates 15. An abutment member is provided on each of the arms 19 to abut with the respective plate 15. In the illustrated example, the 3 abutment member is the axle joining the front wheels. The position of each abutment or axle on the arm 19 may be adjustable to limit the extent of anticlockwise movement of the wheels 18 as required. Alternatively the dimensions of the plate may be varied to provide adjustment.

The trolley also includes a pair of fixed rear wheels mounted on an intermediate 3 position along the carrier.

The drum locating shoes 26 are provided on the bottom of the carrier and are shaped so that they can readily be worked under a drum to support the drum by its

peripheral edges on opposite sides of the drum. Preferably, the drum locating shoes are curved in the manner illustrated and are attached to the plates 15.

The trolley is fitted with a brake assembly 15 (shown in Figure 3) which includes a brake lever 29 and brake cable 30 extending through the hollow frame member 3 and exiting at a point near the front wheels. The centre of the brake lever may include a tightening nut or other locking device to frictionally to hold the brake lever and hence the brake in any set position. The cable may be arranged to operate the brake assembly provided in association with front wheel 18 shown on the right hand side of FIGURE 1. A series of drum rotating wheels 34 mounted in pairs on the cross members 8 and 9 are provided to present a plurality of rotatable surfaces to any drum or similar round object supported by the carrier in order that the object can be rotated as necessary.

This is particularly useful when the carrier is used to support a drum holding liquid in the horizontal position as the drum may be rotated to a point where the bung on the drum can be opened and liquid dispensed from the drum or the drum needs to be rotated to prevent leakage.

As can be seen in the drawings, the drum rotating wheels 34 are provided in pairs. These are mounted on the cross members through a common axle held in a bushing. The bushings are welded to the cross members 8 and 9. Four such pairs of drum rotating wheels will generally suffice for the purposes described above.

Referring to Figure 2, there is shown a drum 40 which is supported on the carrier of the trolley at an angle of about 30° to the horizontal. The drum is firmly secured to the carrier by the drum retainers 27 which are slidably mounted on the frame members 3. The drum retainers 27 include tongues 28 which are adapted to fit over the rim provided at the top of a drum in order to secure the drum firmly to the carrier.

In the configuration shown in Figure 2, the front wheels 18 of the trolley are shown as being pivoted to the most rearward position in order that the carrier is tilted at about 30° to the vertical. Experience has shown that having a stable tilt position of such a magnitude makes it easier to manoeuvre the trolley and heavy drum. The front wheels also have a second position where they are tilted forward in a clockwise manner. As indicated previously, in this position the arms extend at an angle forward of the vertical when the trolley is laid down horizontally.

By having the clockwise forward tilt of the wheels 18 limited to a position where the arms 15 are slightly forward of the vertical position with respect to the carrier, the carrier will also have a second stable rest position in which the carrier can hold the drum in a generally horizontal plane. Thus, the trolley which is shown in the vertical position in Figure 1 can assume a horizontal configuration in which the front wheels of the

trolley are actually held in the generally upright position shown in Figure 1 by the weight of the drum mounted on the carrier working to urge the front wheels in the clockwise direction. This occurs because the arms on which the front wheels are mounted have a stop position which is slightly forward of the vertical. Referring to Figure 3, the brake assembly 50 shown therein includes a housing 51 which is mounted by a way of lock nuts 52 on the plate 15. A brake bolt 53 is slidably located within the brake housing 51 and is connected to the cable 30 which is in turn operated by the brake lever 29.

A spring 53 is mounted in the housing 51 and is arranged to urge the brake bolt 53 in the direction of the front wheel 18 shown in fragmentary form. A series of bolts and nuts 57 and 58 are mounted in circular fashion around the wheel 18 in order that they can come into impingement with the end of the brake bolt 53 when the brake is applied by manipulating the brake lever 29.

In a typical sequence of operations for removing a drum from a pallet using a trolley of the type described with reference to Figures 1 to 3, the trolley will initially be raised to the level of the pallet with the front wheels in their raised position as urged by the coil spring 17 and the trolley being vertical as illustrated in Figure 1.

The tongues 28 of the drum retainers 27 are located over the drum rim. The drum is tilted by pulling back slightly on the drum handles. The drum locating shoes 26 may then be worked underneath the drum using force on the lower axle to push the shoes forward so that they support opposite sides of the bottom of the drum until the sides of the drum come into alignment with and are close to the frame members 3 of the carrier.

An operator may then tilt the trolley backwards with the drum thereon by pulling back on the handles 4. Once tilted to a stable position, the shoes and drum will clear the pallet and the trolley can simply be pulled away. When the front wheels are moved to the stable position by tilting the trolley the coil spring 17, by virtue of the fact that it urges the front wheels 18 in the counterclockwise direction, will act to absorb the shock of the front wheels moving to a lower position. Thus, the trolley can assume the position shown in Figure 2 and it can be readily wheeled around without the operator having to exert any upward or downward pressure to support the weight of the drum.

If it is desired to bring the trolley to a horizontal position, downward pressure may be exerted on the handles thereby causing the front wheels 18 to assume their forward position and bring the carrier and hence drum to a horizontal position. The brake may then be applied to prevent the trolley from moving.

Conversely, if it is desired to bring the drum and trolley from the horizontal to a vertical position, the brake may be applied and forward pressure applied to the handles

to move the wheels to the tilted configuration. Subsequently, upward pressure may be exerted on the handles to tilt the assembly to the vertical position as shown in Figure 1 during which at some point along the arc of tilt, the base of the drum and shoes will contact the floor. The trolley is preferably constructed so that the lower most portion of the carrier when it is in the stable configuration shown in Figure 2 is able to clear a pallet. Thus, it is preferred that the shoes 26 which represent the lower most position of the carrier can clear a typical pallet height in this configuration ie. the lower most edge of the drum locating shoes 26 should be greater than 150 mm which is the normal height associated with pallets. For this purpose, it is preferred that the drum locating shoes be curved in the manner illustrated in order to ensure that there are no projecting parts of the drum locating shoes which extend below the height of a pallet and to assist in locating the drum during placement and removal of the drum to and from the trolley.

While it has been convenient to describe the invention herein in relation to particular preferred embodiments, it is to be appreciated that other constructions and arrangements are also considered as falling within the scope of the invention. Various modifications, alterations, variations and/or additions to the constructions and arrangements described herein are also considered as falling within the ambit and scope of the present invention.