Field of the Invention The invention relates to a manually driven carriage, for transporting infants or the disabled, and/or items or goods and the like. It is particularly applicable to a manually driven carriage with interengageable ground engagement means.

Background of the Invention

Pushchairs provide a useful way for safely securing and transporting infants and all the necessary items one would need to look after and cater for a child. The most common pushchair designs have 3 or 4 wheels for engaging the ground and providing movement. A wheelchair for disabled person tends to have 4 wheels although these may be provided in two pairs of different sizes. A shopping cart, trolley or basket used for transporting items or goods would tend to have 2 or 4 wheels. These wheel arrangements are convenient for the user when the manually driven carriage is being used on a single level, solid, flat surface. However, such traditional wheel arrangements are difficult if not impossible to use, either with or without assistance, when faced with an obstacle such as a flight of stairs, uneven ground or soft ground such as sand or snow.

In most situations the user would need to carry the pushchair, wheelchair, shopping cart or basket in order to traverse a set of stairs. This can be quite difficult if the user is not assisted and can be quite dangerous if, for example, an infant is present in the pushchair whilst being carried or if the infant is removed from the pushchair and carried separately as they will inevitably be left unattended. Furthermore the wheels on a conventional manually driven carriage tend to have difficulty generating friction with sand/snow/mud, and as such the wheels are likely to get stuck or sink which would result in the manually driven carriage being very difficult to manoeuvre in any direction. A number of attempts have been made to solve these problems. WO2007/023277 describes a pushchair with a continuous track wrapped around the main drive wheels on each side of the pushchair, to provide support on uneven surfaces. However, this is not practical in normal use due to the reduced mobility of the track compared with traditional wheels. The continuous track would generate large amount of friction when changing direction during normal everyday use. This would result in it being very difficult for the user to undertake even simple manoeuvres.

Furthermore, if this continuous track system were to be used for traversing stairs which were both high rise and narrow then problems would be encountered when changing direction through a number of flights for example. In addition the low height of the continuous track coupled with a straight nature of the continuous track would result in an unstable ride for both the user and passenger. Such a system is only really suitable for use on a single flight of stairs.

More recently WO2010/034963 describes a manually propelled vehicle with a plurality of wheels secured high up around the outside of a frame, which has an extendable stretching track, as to extend down into a position lower than the main wheels for contact with a surface, and retract back up into its casing. One of the main disadvantages with this system lies with the extendable stretching belt, which is under tension even before it is stretched far lower into position to engage with the ground. This would leave the belt very susceptible to damage through contact with sharp objects whilst stretched under this further tension. Another disadvantage is an inability to change direction quickly without resorting to changing modes back and forth, for example whilst traversing multi level flight of stairs. The very bulky size and possible unnecessary extra weight would also make the use the pushchair quite difficult for the user, as well as being obtrusive to others passing by including the time to fully engage into and out of the two drive modes.

GB2327643 describes a different approach which includes a set of tracks attached the rear wheels via a lever which enables the tracks to slide under the pushchair. This has the disadvantage that the pushchair would be rather unstable with a substantial weight resting upon only one joint. It would also be difficult for the user to traverse stairs or obstacles safely, due to the weight, angle of incline and the angle of the pushchair. Another disadvantage lies in the difficulty in judging the correct time to deploy and un-deploy the tracks on approach to and after encountering an obstacle respectively. Furthermore, it would not be practical to manually force the tracks into place, whilst holding the pushchair both stable and in situ at the desired angle, at the same time as trying to keep the passenger and any items loaded onto the pushchair or held by the use in position.

Summary of the Invention

According to an aspect of the present invention there is provided a manually driven carriage comprising a frame and a plurality of wheels connected to the frame wherein the manually driven carriage further comprises an interengageable ground engagement means moveable from a stowed position to a deployed position and back again.

Preferably the plurality of wheels comprises two front wheels located at the front of the frame and two rear wheels located at the rear of the frame, although other arrangements of wheels are also applicable to the present invention. In an alternative the plurality of wheels comprises one front wheel located at the front of the frame and two rear wheels located at the rear of the frame. In a further alternative the plurality of wheels comprises two front wheels located at the front of the frame and one rear wheel located at the rear of the frame. In yet a further alternative 3, 4 or 5 wheels are provided.

In one alternative the ground engagement means is moveable from the stowed position to the deployed position by raising the rear wheels from a ground engaging position to a non-ground engaging position. In this alternative the ground engagement means is moveable from the deployed position to the stowed position by lowering the rear wheels from a non-ground engaging position to a ground engaging position. Furthermore in this alternative the ground engagement means is fixedly connected to the frame via a connection means and the rear wheels are moveably connected to the frame. In another alternative the ground engagement means is moveable from the stowed position to the deployed position by raising the front wheels from a ground engaging position to a non-ground engaging position. In this alternative the ground engagement means is moveable from the deployed position to the stowed position by lowering the front wheels from a non-ground engaging position to a ground engaging position. Furthermore in this alternative the ground engagement means is fixedly connected to the frame via a connection means and the front wheels are moveably connected to the frame.

Further in the alternative the ground engagement means is moveably connected to the frame via a connection means and the plurality of wheels are fixedly connected to the frame.

In one alternative the front wheels, rear wheels or ground engagement means are pivotally connected to the frame.

In another alternative the front wheels, rear wheels or ground engagement means are telescopically connected to the frame.

Preferably the manually drive carriage further comprises a foot controlled lever adapted to operate the connection means. In one alternative the foot controlled lever acts as a switching mechanism. The foot controlled lever may in one alternative have a solid piece of material or in another alternative be a flexible piece of material that operates the switching mechanism. In the alternative a hand controlled lever may be provided that is adapted to operate the connection means and thus the switching mechanism if provided.

Preferably the connection means comprises a spring or hydraulic assembly.

According to another aspect of the present invention there is provided a manually driven carriage comprising a frame, front wheels located at the front of the frame and rear wheels located at the rear of the frame and an interengageable ground engagement means moveable from a stowed position to a deployed position preferably by raising or lowering the rear wheels and/or the front wheels from a ground engaging position to a non-ground engaging position.

Preferably the ground engagement means comprises a substantially flat surface which contacts the ground when the ground engagement means is in the deployed position. Preferably the substantially flat surface of the ground engagement means contacts the ground substantially at the same height as the wheels located at the front of the frame such that the substantially flat surface and front wheels are all in contact with the ground when the ground engagement means is in the deployed position, and the rear wheels are in the non-ground engaging position. In the alternative the substantially flat surface of the ground engagement means contacts the ground at substantially the same height as the rear wheels located at the rear of the frame such that the substantially flat surface and rear wheels are all in contact with the ground when the ground engagement means is in the deployed position, and the front wheels are in the non-ground engaging position. Preferably the substantially flat surface of the ground engagement means does not contact the ground when the ground engagement means is in the stowed position.

Preferably the manually driven carriage comprises a plurality of ground engagement means, most preferably two sets of ground engagement means.

The ground engagement means may be for example a runner or bracket assembly. Preferably the runner or bracket assembly, or other ground engagement means is connected to the frame of the manually driven carriage separately from both the front wheels and the rear wheels, preferably the ground engagement means and the front wheels are fixedly connected to the frame, whereas the rear wheels are movably connected to the frame so that the position of the rear wheels can move whilst the front wheels and the ground engagement means remain fixed in their position with respect to the frame. Preferably when the rear wheels are moved from a ground engaging position to a non-ground engaging position this results in the whole frame of the manually driven carriage being lowered at the rear of the frame which in turn moves the ground engagement means from the stowed position to the deployed position. In the alternative the ground engagement means and the rear wheels are fixedly connected to the frame, whereas the front wheels are movably connected to the frame so that the position of the front wheels can move whilst the rear wheels and the ground engagement means remain fixed in their position with respect to the frame. In this alternative preferably when the front wheels are moved from a ground engaging position to a non-ground engaging position this results in the whole frame of the manually driven carriage being lowered at the front of the frame which in turn moves the ground engagement means from the stowed position to the deployed position.

Further in the alternative the front wheels and the rear wheels are fixedly connected to the frame, whereas the ground engagement means is moveably connected to the frame so that the position of the ground engagement means can move whilst the front wheels and the rear wheels remain fixed in their position with respect to the frame.

In this alternative preferably when the ground engagement means is moved from the stowed position to the deployed position this results in the whole frame of the manually driven carriage being raised at the front and/or rear of the frame which in turn moves the front and/or rear wheels from their ground engaging position to their non-ground engaging position.

Preferably the ground engagement means are located towards the rear of the frame and extend towards the front of the frame in both the stowed and deployed positions. The ground engagement means preferably takes the place of the rear wheels and/or the front wheels when these wheels are moved to their non-ground engaging position. The ground engagement means may extend to the front wheels.

In one alternative the ground engagement means has a hinge or tongue which when the ground engagement means is in the deployed position is located at the rear of the front wheels to create one single continuous surface between the ground engagement means and each of the front wheels.

The ground engagement means in one alternative are located outside of each of the rear and/or front wheels and in another alternative the ground engagement means are located in between the rear and/or front wheels, inside the wheels. In one alternative the ground engagement means may be located centrally within the frame in between the rear and/or front wheels. It is preferred that the stowed position of the ground engagement means is located high enough above the level of the ground such that it does not contact the ground, more preferably the stowed position of the ground engagement means is not so high that when the ground engagement means is moved to its deployed position it has a large distance to travel to ensure comfort to any passenger and goods in the manually driven carriage.

When the rear and/or front wheels are moved from their ground engaging position to their non-ground engaging position they may move directly upwards relative to the frame and come up either inside the frame or across the frame, or in the alternative may move out or along sideways inside or outside the frame, and/or backwards or forwards relative to the frame. If for example the ground engagement means is located inside the rear and/or front wheels then the ground engagement means cannot move out sideways inside the frame for example.

In the alternative when the ground engagement means is moved from its stowed position to its deployed position it may move directly downwards relative to the frame, or in the alternative may move down sideways inside and outside the frame, backwards or forwards relative to the frame.

Either the front wheels, the rear wheels or both may be able to rotate through 360 ⁵ to enable change of direction of the manually driven carriage. In one alternative the front wheels can rotate through 360 ⁵ , thus in this alternative to change direction when the ground engagement means is in the deployed position the manually driven carriage would need to be tilted onto the front wheels. In a preferred alternative the rear wheels can rotate through 360 ⁵ , in this alternative the rear wheels are moved into a ground engaging position by reverse tilting which enables them to make contact with the ground, to allow for changes in direction when the manually driven carriage is tilted backwards. This is preferred so that items are not inadvertently tilted out of the manually driven carriage, which is particularly applicable in the case of a pushchair or wheelchair when the passenger could be tilted out of the manually driven carriage.

In a further alternative either both or either of the front wheels and the rear wheels may be motorized. Preferably the raising and lowering of the rear and/or front wheels or the ground engagement means is operated by a foot controlled lever located at the bottom of the frame near the rear wheels which would be operated in much the standard way as brakes currently offered on pushchairs and the like.

The foot controlled lever is connected to the rear and/or front wheels or the ground engagement means such that the movement of the foot controlled lever results in the raising or lowering of the rear and/or front wheels or the ground engagement means respectively.

It is convenient to have a foot controlled level as people operating pushchairs are used to operating foot controlled levers for the engagement of wheel brakes, and it would be located close to the rear wheels meaning that moving parts are confined to a relatively small area of the manually driven carriage.

In the alternative a hand controlled level may be provided located on the handlebars for example.

In one alternative the foot controlled level operates solely by depressing the foot controlled lever in a single direction. The first depression resulting in the contraction of a spring assembly or hydraulic assembly or combination thereof resulting in the raising of the rear and/or front wheels to a non-ground engaging position and thus lowering of the frame and the ground engagement means to their deployed position.

In another alternative the final depression results in the expansion of a spring assembly or hydraulic assembly or combination thereof resulting in the lowering of the ground engagement means from the stowed position to the deployed position and thus raising of the frame and the front and/or rear wheels to their non-ground engaging position.

Instead of or in combination with the spring or hydraulic assembly there may be provided a telescopic arrangement with a series of interlocks rather like an umbrella or telescopic handle on pieces of luggage wherein the depression of the foot controlled lever causes the removal of the interlocks (by moving protrusions from a position where they engage apertures in the telescopic members to a non-engaging position) at the same time as the spring or hydraulic contraction to compress or expand the telescopic arrangement, depending on the alternative being employed. On the second depression of the foot controlled lever in the same direction or the opposite direction the spring or hydraulic arrangement would be allowed to expand resulting the lowering of the rear and/or front wheels back to their ground engaging position, resulting in the raising of the frame and thus the ground engagement means back to the stowed position.

In the alternative on the second depression of the foot controlled lever the spring or hydraulic arrangement would contract resulting the raising of the ground engagement means to its stowed position, resulting in the lowering of the frame and thus the rear and/or front wheels back to their ground engaging position.

If a telescopic arrangement is also provided the same action would result in the expansion of the telescopic arrangement and the interlocks between the telescopic arrangement being re-established.

If a hydraulic or compressed air arrangement is employed this would allow for the smooth movement of the relative components, this would allow for a smooth transition between the two modes. In the alternative any other suitable slow release mechanism such as using friction, windings and pulleys or tension may be employed.

Preferably the mechanism employed to move the relative components comprises a locking mechanism able to lock and release when desired the relative components in both their raised and lowered positions or stowed and deployed positions respectively. The locking mechanism may be an automatic process in the raising or lowering process and operate in conjunction with the foot controlled lever, or may in the alternative be a separate operation and operated by a second lever which may also be foot operated or in the alternative hand operated and located on or about the handlebars.

The locking mechanism may be for example a gear fixing, a series of brake teeth, a friction lock or the use of protrusions and aperture or other interlocking system.

Preferably the front and rear wheels incorporate standard barking systems. These standard braking systems may be operable in conjunction with any additional braking system provided for the ground engagement means or may be operable separately there from.

The ground engagement means may comprise runners or brackets, these runners or brackets may comprise a solid plate or skis or in the alternative may comprise a plurality of wheels, gears or spokes which are connected together in order to create a substantially flat ground engaging surface. In one alternative where wheels, gears or spokes are provided they may be spaced apart or may be connected such that they are effectively continuous. The substantially flat ground engaging surface in one alternative is curved upwards towards either both or either of the part of the ground engaging surface closest to the rear or front of the frame. This arrangement allows for smooth movement of the ground engagement means, when deployed, onto the relevant obstacle without having to physically lift the manually driven carriage into position about the obstacle. In a further alternative the ground engagement means may comprise a combination of a solid plate or ski and a plurality of wheels, gears or spikes.

In one alternative the ground engagement means comprises a belt which moves about the ground engagement means, in an alternative the belt is fixed to the ground engagement means such that it cannot move.

The belt if one exists is preferably made from a rubber or plastics material. The belt may be provided with grooves or apertures for providing traction on either its outer ground contacting surface or on its inner ground engagement means contacting surface or both or in the alternative may be smooth and frictionless on its outer ground contacting surface to enable a smooth gliding movement over the relevant obstacles. In a further alternative the belt may comprise a caterpillar track rather like a bike chain. The belt may be provided with a series of ball bearings or the like located between the belt and the ground engagement to assist in the movement of the belt.

In the alternative to a belt a coating may be provided on the ground engaging surface of the ground engagement means formed of a frictionless or friction reducing material such as ceramics, polymeric, metallic or polished wood. The belt, if one is provided may be a continuous belt wrapped around the whole peripheral circumferential surface of the ground engagement means from the front to the rear of the ground engagement means be this a solid plate, ski, wheels, gears or spokes. This is particularly important in the alternative where the belt moves about the ground engagement means. In the alternative the belt may only be provided on the ground engaging surface of the ground engagement means which is most applicable in the case of solid plates or skis where the belt may be fixed.

In a further alternative where two ground engagement means are provided one at either side of the frame they may be connected by one or more cylinders. The belt if one is provided would then rotate about the cylinder.

In one alternative the ground engagement means comprises a braking system which stops the belt from moving about the ground engagement means.

In the alternative where the belt can move about the ground engagement means the braking system may comprise apertures in the belt through which protrusions located on the ground engagement means are adapted to locate and align within the apertures when activated.

In a further alternative the ground engagement means comprises a braking system comprising an anchor means moveable from a stowed position which is not in contact with the ground to a deployed position which is in contact with the ground Preferably the anchor means is adapted to be deployed to a position below the surface of the ground. In one alternative the anchor means comprises a spike. The anchor means holds the manually driven carriage in place whilst the ground engagement means is deployed. Preferably the anchor means when deployed embeds itself between steps, grooves, patches, paving and the like. It may be operable in conjunction with or separately from any other braking system which may be provided.

Preferably the manually driven carriage comprises a harness to connect the manually driven carriage to a user. The harness may be fixed at the top and bottom, and at multiple points of the frame to enable even leverage.

The harness will be made out of any suitable material that is weatherproof, extremely tough and durable fabric or plastic. The need for the harness is to enable the user to have an added connection of themselves to their child/items in the manually driven carriage. This may be very important whilst traversing downwards against gravity, for that extra safety measure and means of lower the carriage without losing one's own balance and control of the situation. It may have connections to fix around the users wrists, legs or waist, or possibly in the alternative is connectable to items of clothing they may be wearing. It could also incorporate full or tightening controls, for the wrists or handles for example.

In a further alternative the harness may in addition be provided with a platform, the platform being adapted for holding a child either standing or seated on the platform or items of goods. This is beneficial in the event that you have 2 children, one of whom insists they can walk, but gets tired along the way and can then "ride" at the back of the pushchair in the harness to avoid the need for a "double buggy" or in the event that only one user is available so 2 pushchairs cannot be taken out.

The harness will aid the user in everyday use so they will not lose connection to the manually driven carriage. Mainly when traversing down inclines and letting it lead by means of gravity. The harness may be permanently attached or it may be detachable such that it can be detached and replaced if needed. The platform may be removable, for multiple positions both front and back facing, and may encompass one, two or more seats.

Preferably the manually driven carriage comprises a seat. The seat may be adjusted to a number of different heights or tilting angles as is known in the art.

In a further alternative telescopic extending or adjustable angled handlebars may be provided so that their height and angle can be adjusted to suit the user between different operating modes. Further in the alternative a second pair or handlebars may be provided mid way up the frame to further provide for ease of use between the different operating modes. These handles would also assist in carrying the manually driven carriage if folded during transportation and storage.

The manually driven carriage may be static or may be adapted to fold away for storage and transportation or the like.

The manually driven carriage may be provided with baskets for storage of items or the like. The manually driven carriage could be used solely for infants/people, solely for goods, or multi capable for the benefits of both. Therefore the manually driven carriage can include child seats, with a shopping basket, together within the frame of the manually driven carriage. It may further comprise a fully encompassing goods basket or the like. The manually driven carriage has the capabilities of a modern wheeled transportation system, but also when needed, a quick interengageable system by means of shifting the position of the main drive wheels relative to the ground engagement means. This will enable a smooth, quick way of traversing obstacles, such as stairs, steps, escalators, or manoeuvring through soft terrain, previously very difficult to accomplish. With this system, the manually driven carriage can be used exactly the same way as with all modern pushchairs, but also with an added mode, easily and quickly transferable, for access across obstacles and multi level access points i.e. snow, mud, steps, stairs, stairways and escalators. This may also include a tilt adjustable seat with the necessary belts, and a safety pulley strap attached to the back of the chassis. The differentials of this manually driven carriage could be 2, 3, 4 or more wheels, with one or more seats and/or a goods basket, and is not limited by any desired design modifications to the rest of frame.

This invention in one alternative relates to a manually controlled carriage, comprising a frame, a set of wheels for one mode of operation, and a set of runners or stabilisers for the second mode of operation. With this system, the manually driven carriage can be used exactly the same way as with all modern pushchairs, but also with an added mode, easily and quickly transferable, for access across obstacles and multi level access points i.e. snow, mud, steps, stairs, stairways and escalators. This may also include a tilt adjustable seat with the necessary belts, and a safety pulley strap attached to the back of the chassis. The differentials of this carriage could be 2, 3 or 4 wheels, with one or two seats and or baskets, and is not limited by any desired design modifications to the rest of frame.

Whilst the main driving wheels are used in normal everyday mode, the ground engagement means will have a clearance away from contact with the ground, thus keeping normal full mobility achievable. They however will make contact with a surface, whilst slightly tilting the frame forwards or backwards when there's a need for a slight change of height for access, i.e. a kerb. The ground engagement means will also help in this case also by leveraging and gliding over the obstacle comfortably, and taking on some of the extra weight and weight distribution. Thus a use even when in normal mode of drive without any adjustments needed to switch between.

The rear wheels will act to enable the ground engagement means clearance from, and contact with the ground when required, i.e. in normal driving mode. In this embodiment the rear wheels when displaced will lower the frame and ground engagement means into making contact with the ground. The weight of the frame and what it's carrying will help enable to make this shift automatic. However to counter the directness and harshness of this weight shift, a suspension or hydraulic system may be an aid for comfort and safety.

Once access has been accomplished, and there is a need for a switch back to the normal mode of driving, the rear wheels are pushed back down displacing the frame and fixed stabilisers back upwards and above from contact with the ground. Due to the weight this may need to be done in conjunction with the user's hands to lift the weight of the frame upwards as the wheels are pushed lower.

All the above movement applies for the wheels as well, i.e. the wheels are in a fixed position, and instead it's the rear end of the runners that move (engage) in and out of position vertically when needed for traversing verses normal road uses. So the front end would still be fixed in position with respect to the chassis or front driving wheels. And the back end of the stabilisers will shift vertically upon an axis, so what would lead to an angled shift of the whole system, into and out of contact with the ground. The back of the stabilisers will shift above and below the rear wheels along a vertical axis, instead of the rear wheels shifting. So, this could either be the front wheels fixed with the back raising/lowering. Or the back wheels fixed with the front lowering/raising.

According to a second aspect of the present invention there is provided an interengageable ground engagement means for a manually driven carriage comprising a frame and a plurality of wheels connected to the frame wherein the interengageable ground engagement means is moveable from a stowed position to a deployed position and back again. This is particularly important if someone has already spent a considerable amount of money on a manually driven carriage which does not have such functionality as it enables the user to conveniently retro-fit such an interengageable ground engagement means to their existing manually driven carriage.

In this aspect of the present invention the when the interengageable ground engagement means is retro-fitted to the manually driven carriage and when the interengageable ground engagement means is moved from the stowed position to the deployed position this results in the whole frame of the manually driven carriage being raised at the front and/or rear of the frame which in turn moves the front and/or rear wheels from their ground engaging position to their non-ground engaging position.

Furthermore in this aspect of the present invention the interengageable ground engagement means may have individually or in combination any of the features described above in relation to interengageable ground engagement mean described in respect of the first aspect of the present invention.

According to a third aspect of the present invention there is provided a harness. The harness is preferably located at the rear of the frame and may be connected to the top and or bottom of the frame and/or multiple points there between. The harness is provided as an additional point of storage of items, or in the alternative may be adapted to hold an additional child.

Preferably the harness may in addition be provided with a platform, the platform being adapted for holding a child either standing or seated on the platform or items of goods. This is beneficial in the event that you have 2 children, one of whom insists they can walk, but gets tired along the way and can then "ride" at the back of the pushchair in the harness to avoid the need for a "double buggy" or in the event that only one user is available so 2 pushchairs cannot be taken out.

The harness may be permanently attached or it may be detachable such that it can be detached and replaced if needed. The platform may be removable, for multiple positions both front and back facing, and may encompass one, two or more seats.

Brief Description of the Drawings Figure 1 is a side view of a manually driven carriage according to the present invention in un-deployed mode;

Figure 2 is a side view of a manually driven carriage according to the present invention in deployed mode;

Figure 3 is a rear side perspective view of a manually driven carriage according to the present invention in deployed mode;

Figure 4 is a rear view of a manually driven carriage according to the present invention in deployed mode;

Figure 5 is a side view of a manually driven carriage according to the present invention in deployed mode traversing a set of stairs; and Figure 6 is a side view of an alternate embodiment of a manually driven carriage according to the present invention in deployed mode.

Description of Preferred Embodiments Referring to Figures 1 to 5 there is provided one alternative of a manually driven carriage which is a pushchair 10. The pushchair 10 has a frame 12, four wheels 14, 16, 18, 20 and two ground engagement means 22, 24. The ground engagement means 22, 24 are provided separately from the wheels 14, 16, 18, 20. The ground engagement means 22, 24 are connected to the frame 12 of the pushchair 10. The ground engagement means 22, 24 are either wheels, gears, spokes, a set of plates, or the like which are connected to create a flat surface. The ground engagement means 22, 24 are each provided with a belt 26, 27. The belt 26, 27 is adapted to circumferentially surround at least a portion of the each of ground engagement means 22, 24. In one alternative the belt 26, 27 is adapted to circumferentially surround each of the ground engagement means 22, 24. In one alternative the belt 26, 27 is formed from a plastics material. In one alternative the plastics material is a polymeric material such as a rubber or elastomeric which is capable of having traction with both the ground engagement means 22, 24 and the ground. In another alternative the belt 26, 27 is formed from a non-plastics material which is capable of having traction with both the ground engagement means 22, 24 and the ground. The belt 26, 27 in one alternative may be provided grooves or a thread to enable the belt 26, 27 to have traction with both the ground engagement means 22, 24 and the ground. The ground engagement means 22, 24 in one alternative may be provided with grooves or a thread or joints to enable the belt 26, 27 to have traction with the ground engagement means 22, 24.

In a further alternative wherein each of the ground engagement means 22, 24 are formed from a set of spokes then the ground engagement means 22, 24 in one alternative are provided with a chain which is adapted to circumferentially surround each of the ground engagement means 22, 24 to which the belt 26, 27 is connected. In this alternative the chain and thus the belt 26, 27 can move around the ground engagement means 22, 24.

The belt 26, 27 may be provided with apertures to allow for fixing means to be used to fix the belt 26, 27 to the chain, if provided, or directly to the ground engagement means 22, 24. In one alternative the belt 26, 27 is removable and replaceable in the event that the belt 26, 27 becomes damaged.

In a further alternative shown in Figure 6 the ground engagement means 122, 124 are skis which in one alternative are provided with a coating on the surface which contacts the ground. The coating in one alternative is a material with a low coefficient of friction to allow smooth running of the ground engagement means 122, 124 over the surface of the ground.

The ground engagement means 22, 24 are connected to the frame 12 of the pushchair 10 such that they move from a stowed position where the ground engagement means 22, 24 make no contact with the ground or any obstacles on the ground to a deployed position where the ground engagement means do make contact with the ground or any obstacles on the ground. The movement of the ground engagement means 22, 24 from the stowed position to the deployed position is controlled by the user by raising or lowering the two rear wheels 18, 20. In the embodiment shown the rear wheels 18,20 are pivotally connected to a lower bar of the frame 12 of the pushchair 10. The pivotal connection means comprises a foot controlled lever such as kick levers 30, 32. The two rear wheels 18, 20 are connected to the respective kick levers 30, 32 and the kick levers 30, 32 are pivotally connected to the lower bar. Movement of the kick levers 30, 32 up or down translates to pivotal movement of the kick lever 30, 32 about the lower bar which in turn raises or lowers the two rear wheels 18,20. In order that both the two rear wheels 18, 20 are raised or lowered at the same time the kick lever 30, 32 are connected via a connection bar 28. In this alternative (as shown) the two rear wheels 18,20 are connected to the respective kick levers 30, 32 and the kick levers 30, 32 are connected to the connection bar 28, the connection bar 28 is then pivotally connected at each of its ends to the frame 12 of the pushchair 10 such that the connection bar 28 can axially rotate in situ. The kick levers 30, 32 and associated apparatus which assist in the movement of the two rear wheels 18, 20 from the ground engaging position to their non-ground engaging position and back again may be provided with springs, stops, catches, locks and the like as known to the skilled person to assist in the movement and to retain the two rear wheels 18, 20 in either the ground engaging or non-ground engaging position as desired by the user. The movement of the two rear wheels from their ground engaging position to their non-ground engaging position results in the lowering of the frame 12, and thus the ground engagement means 22, 24 which are connected to the frame from their stowed position to their deployed position. In an alternative a slow release mechanism may be provided utilising compressed air, friction, winding, grippers or the like to slowly move the two rear wheels 18, 20 from their ground engaging to their non ground-engaging position and back again.

The kick levers 30, 32 which operate to move the two rear wheels 18, 20 from their ground engaging position to their non-ground engaging position and back again in one alternative are operated by the user's feet. In another alternative the kick levers 30, 32 are connected via levers and pulleys to a lever or levers (not shown) on one or other or both of the handlebars 34, 36 of the pushchair 10 and are operated by the user's hands. The mechanism used to move the two rear wheels 18, 20 from their ground engaging position to their non ground engaging position and back again in one alternative has a locking mechanism to retain the two rear wheels 18, 20 in either their ground engaging position to their non ground engaging position as desired by the user.

In the alternative shown the ground engagement means 22, 24 are in line with the front wheels 14, 16, with the rear wheels 18, 20 not being in line with the front wheels 14, 16. In an alternative the front wheels, 14, 16, rear wheels 18, 20 and ground engagement means 22, 24 are all in line with the ground engagement means 22, 24 being located in-between the respective front wheels 14, 16 and rear wheels 18, 20.

During normal everyday use the wheels 14, 16, 18, 20 are used to contact the ground and the ground engagement means 22, 24 remain in the stowed position. This allows for full mobility of the pushchair 10, or other manually driven carriage. The ground engagement means 22, 24 will only come into use in the stowed position when slight tilting of the pushchair 10 or other manually driven carriage occurs when there is a slight change in height from a first ground level to a second ground lever, such as traversing a kerb. The ground engagement means 22, 24 would come into contact with the kerb when in the stowed position and assist and stabilise the movement of the pushchair 10 or other manually driven carriage from the first ground level to the second ground level.

In one alternative the pushchair 10 or other manually driven carriage may be provided with a suspension system or a hydraulic system to assist in the movement of the two rear wheels 18, 20 from their ground engaging position to their non ground engaging position and back again.

In an alternative rather than the two rear wheels 18, 20 moving relative to the frame 12 and the two front wheels 14, 16 and thus the ground engagement means 22, 24 of the pushchair 10 or other manually driven carriage it may be the wheels 14, 15, 18, 20 remain fixed and it is instead the ground engagement means 22, 24 which move relative to the frame 12 and wheels 14, 16, 18, 20 of the pushchair 10. Further in the alternative it may instead be the front wheels 14, 16 which move relative to the frame 12 and ground engagement means 22, 24 of the pushchair 10, or in the alternative it may be all the wheels 14, 16, 18, 20 which move relative to the frame 12 and ground engagement means 22, 24 of the pushchair 10.

Although the ground engagement means 22, 24 described are formed from wheels, gears, spokes, a set of plates, or the like which are connected to create a flat surface, the ground engagement means 22, 24 may in one alternative by adapted to be semi-flexible to allow for smooth engagement between the ground engagement means 22, 24 and the ground when the ground engagement means 22, 24 are in the deployed position and the manually driven carriage is traversing obstacles on the ground which may be curved or have edges or the like.

Further in the alternative the ground engagement means 22, 24 instead of being solely provided parallel with the intended general direction of movement may in addition be provided parallel with the intended general direction of movement as well connecting the ground engagement means 22, 24 by means of cylinders for example.

The length of the ground engagement means 22, 24 needs to be sufficient to span across a minimum of 2 stairs of a staircase, preferably a minimum of 3 stairs of a staircase.

In one alternative both the front 14, 16 and rear wheels 18, 20 incorporate brakes.

In another alternative the ground engagement means 22, 24 also incorporate brakes. In one alternative where the ground engagement means 22, 24 have spokes or the like which they are provided with 'teeth' or 'holes' which when the brake is applied are adapted to engage with protrusions which prevent the spokes or the like from rotating. In the alternative the belt 26, 27 is provided with a plurality of apertures which are adapted to engage with protrusion which prevents the belt from rotating. In a further alternative as shown in Figures 1 to 5 there are also provided anchors 38, 40 which are adapted be moveable from a stowed position to a deployed position to engage with crevices or gaps or the like in the ground to assist in retaining the pushchair 10 in a fixed relationship with the ground when desired by the user. The ground engaging portions of the anchors 38, 40 are adapted to deploy to a position lower than the wheels 14, 16, 18, 20 and the ground engagement means 22, 24 so that the anchors 38, 40 are capable of embedding either directly into the ground or into cracks, crevices, grooves and the like. In a further alternative only one anchor is provided, and in yet a further alternative 3 or more anchors may be provided such as 4 anchors, each one located about a wheel for example.

The anchors 38, 40 may be operated in the same way as the ground engagement means 22, 24 as described above. The anchors 38, 40 are moveably connected to the frame 12 of the pushchair 10 such that they move from a stowed position where the anchors 38, 40 make no contact with the ground to a deployed position where the anchors 38, 40 means do make contact with the ground and embed themselves therein. The movement of the anchors 38, 40 from the stowed position to the deployed position is controlled by the user. In one alternative the anchors 38, 40 are pivotally connected to a lower bar of the frame 12 of the pushchair 10. The pivotal connection means comprises kick levers. The anchors 38, 40 are connected to the respective kick levers and the kick levers are pivotally connected to the lower bar. Movement of the kick levers up or down translates to pivotal movement of the kick lever about the lower bar which in turn raises or lowers the anchors 38, 40. In order that both the anchors 38, 40 are raised or lowered at the same time the kick levers are connected via a connection bar. In this alternative the anchors 38, 40 are connected to the respective kick levers and the kick levers are connected to the connection bar, the connection bar is then pivotally connected at each of its ends to the frame 12 of the pushchair 10 such that the connection bar 28 can axially rotate in situ. The kick levers and associated apparatus which assist in the movement of the anchors 38, 40 from the stowed position to the deployed position and back again may be provided with springs, stops, catches, locks and the like as known to the skilled person to assist in the movement and to retain the anchors 38, 40 in either the stowed or deployed positions as desired by the user. In an alternative a slow release mechanism may be provided utilising compressed air, friction, winding, grippers or the like to slowly move the anchors 38, 40 from the stowed position to the deployed position and back again. The kick levers which operate to move the anchors 38, 40 from the stowed position to the deployed position and back again in one alternative are operated by the user's feet. In another alternative the kick levers are connected via levers and pulleys to a lever or levers on one or other or both of the handlebars 34, 36 of the pushchair 10 and are operated by the user's hands.

In one alternative the anchors 38, 40 may be arranged such that when the ground engagement means 22, 24 are deployed the anchors 38, 40 are also automatically in the deployed position and need to be raised and held in the raised position, rather like starting a lawnmower or the like when a secondary lever has to be held at all times when the lawnmower is in the on position.

The mechanism used to move the anchors 38, 40 from the stowed position to the deployed position and back again in one alternative has a locking mechanism to retain the anchors 38, 40 in either the stowed position or the deployed position as desired by the user.

In a further alternative the ground engagement means 22, 24 are each provided with a hinge or tongue 50 adapted to bridge the gap between the ground engagement means 22, 24 and the front wheels, 14, 16 and engage with the front wheels 14, 16 to create a continuous surface between the front wheels 14, 16 and the ground engagement means 22, 24.

In a further alternative as shown the pushchair 10 further incorporates a harness 42 connected to the back of the frame of the pushchair 10. The harness 42 in the embodiment shown is connected to the top and the bottom of the frame as well as at a number of points there between.

The harness 42 is adapted to connect the user to the pushchair. The harness 42 has connecters adapted to connect around the users wrists, ankles or waist. The harness 42 when connected to the user makes the user feel safe that the pushchair will not slip out of their grasp when traversing a steep slope such as a set of stairs. In a further alternative the harness 42 has connectors adapted to connect to parts of clothing that the user is wearing or in another alternative to connect to a secondary harness worn by the user. The connectors can clip into place and the harness and connectors may be adjustable.

The harness 42 in another alternative includes means for attachment of an additional seat or standing platform at the back of the pushchair.

In a yet a further alternative the main seat 44 of the pushchair 10 is adapted to move from a first angled position to a second angled position. The main seat 44 includes a twist gearing mechanism as used in manually controlled adjustable car seats for example to move the main seat 44 from a first angled position to a second angled position. In a further alternative the pushchair has two or more harnesses.

In another alternative the pushchair is provided with tilting vertical extendable handle bars which run the full height of the frame. These tilting handle bars, would be adapted to tilt forwards and backwards at the user requires, depending on whether the user is traversing up or down an obstacle. The tilt in the handle bars in one alternative is accomplished by using a twist gearing mechanism as used in manually controlled adjustable car seats for example to move the tilting handlebars from a first tilted position to a second tilted position. In another alternative as shown the pushchair is provided with secondary handles 46, 48.

The heights of the handlebars are adjustable and can be locked into position at a height and or angle to suit the user.

In a further alternative instead of a pushchair a trolley or the like may be provided which is provided with a basket instead of a seat for transportation of goods and the like.