This invention relates to a load transporting apparatus. Such apparatus are used to push or pull heavy loads over a ground surface and typically include ground engaging wheels which are driven by a motor to effect said movement. In order to ensure efficient drive, it is desirable to transmit some of the weight of the load to be moved on to the ground engaging wheels, to ensure a good grip with the ground surface during movement.

One prior art such apparatus includes a pair of driven ground engaging wheels which permit the apparatus to pivot about the contact point of the wheels with the ground surface. Such pivoting permits a coupling connected to a front of the apparatus to be positioned under a load. A user then manually pivots the apparatus to lift the coupling, and thus the, or a portion of the, load, which ensures a transfer of a portion of the weight of the load onto the wheels. One disadvantage with this and other forms of such apparatus is that they can be difficult to manoeuvre, not only when engaged with a load, but also when being moved into position adjacent a load. Particularly, due to the pivoting configuration of the apparatus, the user graspable handle thereof is often in an inconvenient (e.g. low) position when the user commences use of the apparatus.

According to a first aspect of the invention we provide a load transporting apparatus including:

a main body;

at least one ground engaging wheel positioned at or towards one end of the main body and supported for rotation about a generally horizontal axis;

H13127WO at least one wheel assembly positioned at or towards an opposite end of the main body and including a wheel which is supported for rotation about a generally horizontal wheel axis, wherein said wheel assembly permits the wheel to swivel about a swivel axis which is substantially perpendicular to the wheel axis and off-set therefrom;

wherein the wheel assembly is connected to the main body by connection means which permits movement of the main body towards and away from the wheel assembly, and there being biasing means for biasing the main body away from the wheel assembly,

wherein the connection means is configured such that the swivel axis of the wheel assembly is maintained substantially vertical as the main body moves towards and away from the wheel assembly.

The connection means is prefereably configured to cause the wheel assembly to follow an arcuate path as it moves towards and away from the main body.

The arcuate path may be a portion of a circumference of a circle, preferably with its centre being substantially coinciding with or near the axis of rotation of the at least one ground engaging wheel.

The connection means may include at least one arcuate guide along which a guide member is moveable.

One of the arcuate guide or guide member may be connected to the wheel assembly and the other of the arcuate guide or guide member may be connected to the main body.

The connection means may include a pair of arcuate guides, one positioned at each side of the wheel assembly, and each having a respective guide member moveable therealong.

H13127WO The connection means may include a pair of arcuate guides at each side of the wheel assembly, and each having a respective guide member moveable therealong. Two or more guide members may be moveable along each arcuate guide.

At each side of the wheel assembly one of the arcuate guides may support more guide members than the other of the arcuate guides. At each side of the wheel assembly one of the arcuate guides may support two guide members and the other of the arcuate guides may support three or more guide members.

The or each arcuate may have an opening at one end, which is closed by a removable closing member.

The opening may face downwardly away from the main body.

The or each guide member may be rotatable about a respective axis.

The axis may be substantially parallel with the axis of rotation of the at least one ground engaging wheel.

The or each guide member may be cylindrical.

At least a portion of the or each guide member may be arcuate.

The biasing means may be connected at one end to the main body and at its opposite end to the wheel assembly.

H13127WO The biasing means may be pivotally connected to the main body about an axis which is substantially parallel with the wheel axis.

The biasing means may be pivotally connected to the wheel assembly about an axis which is substantially parallel with the wheel axis.

The biasing means may be positioned in between a pair of arcuate guides.

The biasing means may include a piston / cylinder arrangement

The biasing means may include a spring and a damper.

The apparatus may include drive means for effecting rotation of the at least one ground engaging wheel about its rotational axis.

The apparatus preferable includes a pair of ground engaging wheels positioned at or towards the end of the main body opposite the wheel assembly, said pair of wheels being rotatable about a common axis. The apparatus may include a pair of said wheel assemblies. The pair of wheel assemblies may be positioned adjacent each other.

By way of example, the apparatus may include one ground engaging wheel positioned at or towards one end of the main body and a pair of wheel assemblies positioned at or towards an opposite end of the main body. Alternatively, the apparatus may include a pair of ground engaging wheels positioned at or towards one end of the main body and one wheel assembly positioned at or towards an opposite end of the main body. Alternatively still, the apparatus may include a pair of ground engaging wheels positioned at or towards one end of the main body and a pair of wheel assemblies positioned at or towards an opposite end of the main body.

H13127WO The apparatus may include coupling means connected to the main body for coupling to a load to be transported. Embodiments of the invention will now be described by way of examples only with reference to the following drawings, of which:

Figure 1 is a rear perspective view of a first embodiment of an apparatus in accordance with the present invention;

Figure 2 is a front perspective view of the apparatus of figure 1 ;

Figure 3 is a side view of the apparatus of figure 1 in first and second operative conditions;

Figure 4 is a cross-sectional view of the apparatus of figure 1 in the second operative condition;

Figure 5 is a cross-sectional view of the apparatus of figure 1 in the first operative condition;

Figure 6 is a rear perspective view of a second embodiment of an apparatus in accordance with the present invention; Figure 7 is a front perspective view of the apparatus of figure 6;

Figure 8 is a cross-sectional view of a first embodiment of a wheel assembly for use in either the first and second embodiments of the invention shown in a first operative condition;

Figure 9 is a side view of the wheel assembly of figure 8;

H13127WO Figure 10 is a cross-sectional view of the wheel assembly of figures 8 and 9 shown in a second operative condition; Figure 1 1 is a side view of the wheel assembly of figure 10, again shown in a second operative condition;

Figure 12 is a perspective view of the first embodiment of the wheel assembly shown in a first operative condition;

Figure 13 is a further perspective view similar to figure 12 but with certain component parts removed;

Figure 14 is a cross-sectional view of a second embodiment of a wheel assembly for use in either the first and second embodiments of the invention shown in a first operative condition;

Figure 15 is a side view of the wheel assembly of figure 15; Figure 16 is a cross-sectional view of the wheel assembly of figures 14 and 15 shown in a second operative condition;

Figure 17 is a side view of the wheel assembly of figure 16, again shown in a second operative condition;

Figure 18 is a perspective view of the first embodiment of the wheel assembly shown in a first operative condition; and

Figure 19 is a further perspective view similar to figure 18 but with certain component parts removed.

H13127WO Referring firstly to figures 1 to 5, these show a first embodiment of a load transporting apparatus 10 in accordance with the present invention. The apparatus 10 includes a main body 12 which houses the internal working components of the machine, e.g. motor, drive assembly, differential. Connected to the main body is a pair of ground engaging wheels 14a, 14b which are positioned towards a front end of the main body 12 and supported for rotation about a generally horizontal axis 15.

A rear end of the main body 12 is supported by a wheel assembly 20, which in this example is a castor wheel assembly. In other words, the wheel 21 of the wheel assembly is supported for rotation about its own generally horizontal axis 22, but is also permitted to swivel about a generally vertical swivel axis 23 which is substantially perpendicular to the wheel axis 22 of offset therefrom. The wheel assembly 20 will be described in greater detail hereinafter.

The apparatus 10 includes a handle/control 50 which serves to provide a user graspable handle to control the direction in which the apparatus 10 moves. The handle 50 includes controls for controlling the speed of rotation of the pair of ground engaging wheels 14a, 14b which are driven by an appropriate motor 16. A front end of the apparatus 10 includes a coupling 60 for engaging with or coupling to a load to be transported (either pushed or pulled by the apparatus 10).

Referring to figures 6 and 7, these show a second embodiment of an apparatus 10' in accordance with the present invention. Features of the apparatus 10' in common with the apparatus 10 are shown with the same reference numerals. Instead of a fixed coupling 60 for engaging with or connecting to the load to be transported, the apparatus 10' includes a hydraulically operable coupling 70 having a coupling arm 62 which is pivotally connected to an upper part of the main body 12. The arm 62 is moveable upwardly and downwardly in the direction of the arrow 64 so as to lift/lower a

H13127WO load to which it is connected. In addition, the arm 62 can be rotated about a generally vertical axis 63 in either of the directions of the arrow 65a or 65b. This positioning of the arm 62 relative to the main body 12 can be used for connecting to a load which is positioned to either side of the apparatus 10'.

The wheel assembly 20 is connected to the main body 12 by connection means (not shown in figures 1 to 7) which permits movement of the main body 12 towards and away from the wheel assembly 20. This connection ensures that the apparatus 10, 10' can be pivoted generally about the axle 15 downwardly at its rear end (as shown in figure 3). As can be seen from figure 3, this pivoting about the axis 15 of the ground engaging wheels 14a, 14b lifts the coupling 60, 70 upwardly in order to apply a lifting force to the load. This lifting force ensures that at least a portion of the weight of the load is transferred through the coupling 60, 70 to the ground engaging wheels 14a, 14b, to ensure that they have enough grip during use. Position A shown in figure 3 corresponds to an operative configuration of the apparatus, where the apparatus is engaged with/connected to a load. Configuration B corresponds to a non-operative condition, where the apparatus is not engaged with/connected to a load.

Advantageously the connection means of the apparatus 10, 10' is configured such that the swivel axis 23 of the wheel assembly 20 is maintained substantially vertical as the main body 12 moves downwardly towards to the wheel assembly 20 and the ground (i.e. as it moves between positions A and B). Ensuring that the swivel axis 23 of the wheel assembly 20 is maintained substantially vertical during this movement is beneficial as it ensures that the castor wheel 21 is free to swivel about its swivel axis 23 in all in use conditions - i.e. either in position A, position B, or any position therebetween. The maintenance of the swivel axis 23 is achieved by virtue of the connection means which is configured to cause the wheel assembly 20 to follow

H13127WO substantially an arcuate path as it moves towards and away from the main body 12.

Figures 8 to 13 show various views of a first embodiment of a wheel assembly 20 for use with either the first or second embodiments of the apparatus 10, 10'. Figures 14 to 19 show various views of a second embodiment of a wheel assembly 20', which, again, can be used with either the first or second embodiments of the apparatus 10, 10'. It is important to highlight that both of these configurations of wheel assembly 20, 20' ensure that the swivel axis 23 of the wheel assembly 20, 20' is maintained substantially vertical as the main body 12 moves towards and away from the wheel assembly 20, 20'. In both wheel assemblies 20, 20' the arcuate path which the connection means is configured to cause the wheel assembly to follow is a portion of a circumference of a circle, with its centre being substantially coinciding with or near the axis of rotation 15 of the ground engaging wheels 14a, 14b. Whilst it is not essential for the arcuate path to have its centre exactly coinciding with the axis 15, the closer the centre of the arcuate path is to the axis 15 ensures a better vertical alignment of the swivel axis 23 during movement. Both embodiments of wheel assembly 20, 20' including arcuate guides along which guide members are moveable in order to control the relative positioning of the castor wheel 21 and its swivel axis 23 relative to the main body 12.

Referring firstly to figures 8 to 13, these show the castor wheel 21 being connected in a conventional manner to a support frame 29 which supports at one end thereof, three cylindrical guide members 33, each of which is rotatable about a respective axis which is substantially parallel to the wheel axis 22. An opposite end of the support 29 supports a pair of further guide members 34 which are, again, supported for rotation about respective axes which are substantially parallel with the wheel axis 22.

H13127WO The guide members 33, 34 are substantially identical to each other and extend through spaced apart upright extensions of the support 29 such that free ends of the guides 33, 34 extend outwardly therefrom. These free ends of the guide members 33, 34 engage with respective arcuate guides or channels in a connection part 27.

The connection part 27 is, in this example, a fabricated metal housing which includes an opening at its lower end to receive the support 29. Its upper end includes apertures for connecting the connection parts 27 to the main body 12. The connection member 27 includes four arcuate guides/channels 31 , 32, two provide it at each side thereof. A forwardly located pair of arcuate guides 32 support the free ends of the guide members 33. A rearwardly located pair of guides 31 support the free ends of the guide members 34. The arcuate guide/channels 31 , 32 are configured such that they follow a portion of a circumference of a circle, with its centre being substantially coinciding with or near the axis 15 of the wheels 14a, 14b. The arcuate guides 31 , 32 each terminate downwardly at an opening which is closed by a removable closing member 40. The member 40 is connected to the connection member 27 by appropriate fasteners and ensures that the guide members 33, 34 are retained in their respective guides 31 , 32.

As shown more clearly in figure 8 and 10 the wheel assembly 20 includes biasing means 36 for biasing the connection part 27 away from the support 29. In use the biasing means 36 biases the main body 12 away from the wheel assembly 20. In more detail the biasing means includes a piston/cylinder arrangement including a spring and damper one end of which is pivotally connected at 37 to the connection member 27 and an opposite end of which is connected at 38 to the support 29. Advantageously the piston/cylinder 36 is positioned in between the upright extension parts of the support 29 and thus is contained within the envelope of the wheel assembly 20. It should be appreciated that other forms of biasing means can be used in place of the

H13127WO piston/cylinder 36. All that is required is that the biasing means urges the wheel assembly 20 away from the connection, at connection part 27 and thus the main housing 12 when it is connected thereto. Figure 8 and 9 show the wheel 21 in an extended, first operative condition which corresponds to the position of the apparatus 10 indicated at B in figure 3. It can be seen that in this configuration the swivel axis 23 of the wheel assembly is substantially vertical. Figures 10 and 1 1 show the wheel assembly 20 in a retracted, second condition which corresponds to the apparatus 10 indicated with a reference A in figure 3. It can be seen that even though the connection member 27 has moved towards the wheel 21 , the swivel axis 23 is still maintained substantially vertical.

As mentioned above, figures 14 to 19 show a second embodiment of a wheel assembly 20' in accordance with the present invention. Features and component parts in common with the first embodiment 20 are shown with the same reference numeral and will not be described in any further detail here. The wheel assembly 20' also relies on two pair of guides/channels 31 ', 32' positioned at each stage of the connection member 27, but rather than each guide supporting a plurality of guide members, as it the case in the first embodiment, here only a single guide member 33', 34' is supported and moveable along each channel 31 ', 32'. In addition, the arcuate guides 31 ', 32' do not have a lower open end, but are rather formed completely in downwardly extending side walls of the connection member 27. The guides 33', 34' are generally cylindrical and each has a respective axis which is substantially parallel with the wheel axis 22. However, these guide members 33', 34' are not of themselves rotatable, although they could be. They act as brushings which slide along the guides 31 ', 32'.

H13127WO In order to ensure a smooth travel of the wheel 21 towards and away from the connection member 27 a further arcuate guide 39 is provided on an inwardly facing surface of the downwardly extending walls of the connection member 27 (see figure 19 for more detail). This guide 39 is provided by the space between a pair of arcuate members 36', 37' which are fastened to the inwardly surface of the wall. This guide 39 receives a plurality (three in this example, although there could be more or fewer) rotatable guide members 35', e.g. bearings, which are each rotatable about an axis which is substantially parallel with the wheel axis 22.

Figures 14 and 15 show the wheel assembly 20' in its extended position which corresponds to the position of the apparatus indicated by reference B in figure 3. Figures 16 and 17 show the wheel assembly 20' in a retracted position which corresponds to the position of the apparatus indicated by reference A in figure 3. It will be seen that in all four figures, the swivel axis 23 is maintained substantially vertical.

Whilst in the above examples the guide members are shown as generally cylindrical members which are either fixed or rotatable about an axis, it is possible to use guide members of other shapes whilst still providing the required functionality. For example, the guide members may of themselves be arcuate in shape such that they can slide along their respective guide/channel. In addition, whilst embodiments of the wheel assembly 20, 20' show a plurality of arcuate guides/channels, it is possible to configure the wheel assembly such that it includes only a single arcuate guide and a single arcuate guide member. In addition, greater or fewer guide members can be used.

In the above examples the apparatus 10, 10' includes a pair of ground engaging wheels positioned towards the front of the main body 12 and a single castor wheel 20, 20' positioned towards a rear of the main body 12. An alternative configuration is envisaged where a single drivable ground engaging

H13127WO wheel is positioned towards the front of the main body and pair of castor wheel assemblies is provided towards a rear of the main body. Each of said wheel assemblies is configured such that it functions as the first and/or second embodiments of the wheel assembly 20, 20' discussed above.

In a further alternative embodiment it is envisaged that a pair of wheel assemblies are provided at a rear end of the main body in combination with a pair of driven ground engaging wheels positioned at the front end of the main body.

In yet a further embodiment it is envisaged that an apparatus in accordance with the present invention may include a single ground engaging wheel positioned towards the front of the main body and a single castor wheel assembly positioned towards a rear of the main body. In such an embodiment, in order to ensure that the apparatus is laterally stable, the width of the single driven ground engaging wheel may be increased (as compared with the examples shown in the figures) to provide lateral stability or alternatively additional supports e.g. smaller castor wheels, could be positioned at either side of the driven ground engaging wheel.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

H13127WO