Description of Invention

This invention relates to an apparatus for transporting a load.

More particularly, this invention relates to an apparatus for transporting a load by pushing or pulling the load over a ground surface. Such apparatus typically include a ground engaging wheel or wheels which are driven by a common electric motor or by respective electric motors to effect said movement. The apparatus is connectable to or engageable with the load so as to move it.

According to a first aspect of the invention, we provide an apparatus for transporting a load including: a main body; a ground engaging wheel positioned at or towards an end of the main body and supported for rotation about a generally horizontal axis A; a motor supported on or by the main body and within a motor housing, the motor being drivingly connected to the wheel so as to rotate the wheel about the axis A and move the apparatus over a ground surface, wherein the motor is an electric motor with a rotor which is caused to rotate by a stator when the latter is electrically powered, wherein the motor includes a rotor brake which is moveable between a braked condition which, when the stator is not electrically powered, prevents or at least inhibits the rotor from rotating, and an unbraked condition which, when the stator is not electrically powered, permits the rotor to rotate, wherein the apparatus includes a rotor brake actuation device having a user actuatable member which is accessible from outside the motor housing, which rotor brake actuation device is moveable between a first condition, which corresponds to the rotor brake being in a braked condition, and a second condition, which corresponds to the rotor brake being in an unbraked condition.

According to a second aspect of the invention, we provide an apparatus for transporting a load including: a main body; a ground engaging wheel positioned at or towards an end of the main body and supported for rotation about a generally horizontal axis A; first and second motors supported on or by the main body and within a motor housing, the motors being drivingly connected to respective wheels so as to rotate the wheels about a common wheel axis A, wherein the motors are electric motors, each with a respective rotor which is caused to rotate by a respective stator when the latter is electrically powered, wherein each motor includes a rotor brake which is moveable between a braked condition which, when the stator is not electrically powered, prevents or at least inhibits the rotor from rotating, and an unbraked condition which, when the stator is not electrically powered, permits the rotor to rotate, wherein the rotor brake actuation device is moveable between a first condition, which corresponds to the rotor brakes of both motors being in a braked condition, and a second condition, which corresponds to the rotor brakes of both motors being in an unbraked condition.

The user actuatable member may be accessible from outside the motor housing.

Further features of the various aspects of the invention are set out in the claims appended hereto.

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 perspective view of an embodiment of an apparatus according to the invention;

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

Figure 3 is a perspective view of the end of the apparatus of figure 2 with a cover member removed showing internal components;

Figure 4 is a further perspective view of the end of the apparatus of figure 2 with a cover member removed showing internal components;

Figure 5 is a perspective view of a motor of the apparatus;

Figure 6 is a perspective view of components parts of a motor braking device of the apparatus;

Figure 7 is a perspective close-up view of component parts of the motor braking device of figure 6;

Figure 8 is a further perspective close-up view of component parts of the motor braking device of figure 6;

Figure 9 is a front view of the apparatus with the motor braking device in a motor braked condition;

Figure 10 is a perspective close-up view of the motor braking device in a motor braked condition;

Figure 11 is a front view of the motor braking device in a motor braked condition; Figure 12 is a front view of the apparatus with the brake release device in motor unbraked condition; and

Figure 13 is a front view of the brake release device in a motor unbraked.

Referring to the figures, these show a load transporting apparatus 10 including a main body 12, which in this example is fabricated from metallic sheet material, although it could be made by any suitable means and from suitable materials. The main body 12 supports a pair of ground engaging first wheels 20a, 20b positioned at or towards a first, front, end 13 of the main body 12 which rotate about a common generally horizontal axis A. Inside the main body 12 is positioned a drive system including one or more motors and suitable gearing for driving the wheels 20 in both rotational directions to as to move the apparatus 10 forwards or rearwards. Positioned at or towards an opposite, rear, end 14 of the main body 12 is a wheel assembly (not shown) which includes a wheel supported for rotation about a generally horizontal wheel axis. The orientation of the wheel of the wheel assembly is moveable relative to the main body 12 so as to effect or assist with steering of the apparatus 10, as is well known in the art.

The main body 12 includes a number of panels 16a, 16b, 16c. The panels 16a, 16b are mirror images of each other and are positioned generally to each side of the main body 12. The panels 16a, 16b surround and cover a portion of each of the wheels 20a, 20b and wrap around the front end 13 of the apparatus 10 where they meet a front panel 16c. The panels 16a, 16b may be removed to as to unbrace one or both of the motors, as discussed in detail later. Figure 2 shows the panels 16a, 16b, 6c in situ, whilst in figure 3 they have all been removed.

The apparatus 10 includes a user graspable handle 15 which is connected to the main body 12 at the end 14 of the main body 12 and generally above the wheel assembly. The handle 15 includes a graspable part at its upper free end which includes controls for controlling the forwards/rearwards movement of the apparatus 10 in use, again as is well known in the art.

Although not shown, the apparatus 10 may include a coupling or the like at the front end 13 of the apparatus 10 adjacent the wheels 20a, 20b for coupling to a load to be transported.

The apparatus 10 includes first and second motors 30a, 30b supported on or by the main body 12 and within a motor housing 32. The motor 30a is drivingly connected to the wheel 20a so as to rotate the wheel 20a about the axis A. The motor 30b is drivingly connected to the wheel 20b so as to rotate the wheel 20b about the axis A. The motors 30a, 30b are positioned adjacent each other within the motor housing 32.

The motors 30a, 30b are electric motors, each with a respective rotor which is caused to rotate by a respective stator when the latter is electrically powered. Thus, the apparatus 10 includes one or more suitable power units, e.g. one or more batteries, to provide electric power to the motors, as required. In the present example, the rotor of each motor 30a, 30b is connected directly to its respective wheels 20a, 20b, although in other examples that need not be the case. For example, the connection might be made by way of suitable gearing. The axis of the rotor may therefore not need to be coaxial with the wheel axis.

In examples, the apparatus may have only one motor which is configured to provide drive to both wheels, e.g. through suitable gearing. In other examples, the apparatus may have only one driven wheel, which wheel may be generally centrally located. In examples, the driven wheel or wheels of the apparatus may be steerable relative to the main body. Each motor 30a, 30b includes a rotor brake which is moveable between a braked condition which, when the stator is not electrically powered, prevents or at least inhibits the rotor from rotating, and an unbraked condition which, when the stator is not electrically powered, permits the rotor to rotate. Motors with such rotor brakes are well known. An example (there are other types) of such a rotor brake includes a first friction plate mounted onto the motor rotor which is able to move (although only a small distance, e.g. a millimetre) along the rotor, but rotates with the rotor. A second friction plate is provided connected to the motor housing. When no electrical power is supplied to the motor, springs act on the first friction plate and press it against the second friction plate. This means that the motor rotor cannot rotate. When electrical power is supplied to the motor, the stator produces an electromagnetic field which overcomes the spring force and separates the first and second friction plates from each other, thus permitting the rotor to rotate. This means that in the braked condition, with the plates frictionally engaged, the wheels 20a, 20b cannot freely rotate about their shared axis A.

If electrical power is not provided to the stator, but it is desired to rotate the rotor, each motor is advantageously provided with a lever member 35a, 35b connected to the rotor brake for moving the rotor brake between its braked and unbraked conditions. This lever 35a, 35b is moveable so as to mechanically overcome the spring force holding the first and second friction plates in contact, thus permitting the rotor to rotate. Figure 5 shows the lever 35b got the motor 30b and the direction 35 in which the lever 35b need to be moved so as to disengage the friction plates.

Advantageously, the apparatus 10 includes a rotor brake actuation device 50 having at least one user actuatable member 60 which is accessible from outside the motor housing 32. The rotor brake actuation device 50 is moveable between a first condition, which corresponds to the rotor brake of both motors 30a, 30b being in a braked condition, and a second condition, which corresponds to the rotor brake of both motors 30a, 30b being in an unbraked condition. Advantageously, the rotor brake actuation device 50 is configured to synchronously move the rotor brakes of both motors 30a, 30b to their braked conditions and configured to synchronously move the rotor brakes of both motors to their unbraked conditions. However, in other envisaged embodiments, the apparatus may include a first rotor brake actuation device for moving the rotor brake of the first motor 30a between its braked and unbraked conditions and a second rotor brake actuation device for moving the rotor brake of the second motor 30b between its braked and unbraked conditions.

The rotor brake actuation device 50 is positioned inside the motor housing 32, generally behind the panel 16c and in front of the motors 30a, 30b, although it could be positioned elsewhere. The device 50 includes a rotationally movable shaft 51 which is supported at its opposite ends by support parts 17a, 17b. The supports parts 17a, 17b are positioned inside the motor housing 32 and are connected to opposing walls of the motor housing 32. Each free end of the shaft 51 is connected to a user actuatable member 60, which in this example is square in cross-section, permitting it to be grasped by a spanner or the like to effect rotation of the shaft about its axis B (which axis is substantially parallel to the wheel axis B, although it not need be). Each user actuatable member 60 extends through an aperture 63 in a respective side wall of the motor housing 32. As seen in figure 7, the apparatus includes a safety device 61 which is releasably connectable to an outwardly facing surface of the motor housing 32 around the aperture 63. The device 61 includes an aperture which is square in cross-section through which the square-shaped portion of the user actuatable member 60 extends. When connected to the motor housing wall 32, by removable fasteners 62, the device 61 ensures that the shaft 51 cannot be rotated. The shaft 51 is threaded along most of its length with there being two distinct threaded sections 51a, 51 b which are separated by a non-threaded section (in the middle of the shaft 51 ). The threads 51a and 51b are oppositely threaded, meaning that one is a left-hand thread and the other a right hand thread, the purpose of which will become clear later.

The rotor brake actuation device 50 includes a pair of moveable member 52a, 52b which are supported by the rotatable shaft 51. Each moveable member 52a, 52b includes a threaded recess or passage 53 through which the shaft 51 passes. This means that as the shaft 51 is rotated, each moveable member 52a, 52b translates towards or away from its respective user actuatable member 60. Because the threaded sections 51 a, 52b are oppositely threaded, as the shaft 51 rotates, the moveable members 52a, 52b either move towards or away from each other.

Each moveable member 52a, 52b is connected to a respective connection member 54a, 54b which extends generally vertically away therefrom and towards the ground surface.

The connection member 54a is connected at or near its first (upper) end 55 to the moveable member 52a and at or near its second, substantially opposite, lower end 56 it is supported for pivotal movement about an axis C relative to the main body 12. The pivotal connection is provided by an axle 74 supported relative to the main body 12. The lower end 56 of the connection members 54a is positioned further away from the wheel 20a than the upper end 55 of the connection member 54a.

The connection member 54b is connected at or near its corresponding first (upper) end 55 to the moveable member 52b and at or near its corresponding second, substantially opposite, lower end 56 it is supported for pivotal movement about an axis D relative to the main body 12. The pivotal connection is provided by a respective axle 74 supported relative to the main body 12. The lower end 56 of the connection members 54b is positioned further away from the wheel 20b than the upper end 55 of the connection member 54b.

Therefore, the lower ends 55 of the connection members 54a, 54b are positioned closer to each other than are the upper ends 55 of the connection members 54a, 54b.

Each connection member 54a, 54b is dogleg shaped in that it includes three sections connected to each other in the following order: a) A first section 71 which includes the pivotal connection to the main body; b) A second, middle, section 72 which includes a connection to a portion of the lever member 35a, 35b (discussed later); and c) A third section 73 which includes the connection to its respective moveable member 52a, 52b.

Each section may be substantially linear (although they may be curved), with the first section 71 being inclined at an angle 75 relative to the second section 72. The third section 73 may be inclined at an angle 76 relative to the second section 72. In embodiments the first and third sections 71 , 73 may be substantially parallel to each other, e.g. angles 75 and 76 may be the same or substantially the same.

The connection between the first end 55 of each connection member 54a, 54b and its respective moveable member 52a, 52b is provided in the form of an opening or slot 58 in the connection member and a projection 59 on the moveable member 52a, 52b which is positioned in and slidably moveable along the opening 58. The lever members 35a, 35b are connected to or engageable by a respective one of the connection members 54a, 54b at a position between its first and second ends 55, 56. In embodiments, the second section 72 of each connection member 54a, 54b includes an opening or slot 57 which receives the free end of a respective one of the lever members 35a, 35b, with the slot being longer than the width of the received part of the lever member 35a, 35b such that slidably movement can occur.

The rotor brake actuation device 50 works as follows. Figure 11 shows the device 50 in a position corresponding to rotor brakes of both motors 30a, 30b being in a braked condition. Here, it can be seen that the lever members 35a, 35b have not been moved towards each other (see figures 9 and 10).

If a user requires the brakes of the motors 30a, 30b to be released, e.g. if there has been a malfunction or failure in one or both motors, then the user firstly has to remove the panels 16a, 16b at each side of the apparatus 10. The user then removes the safety devices 61 which permit the shaft 51 to rotate. The user then attaches a suitable tool, e.g. a spanner, to one of the user actuatable members 60 and rotates the shaft 51 such that the moveable members 52a, 52b move towards each other in the direction of arrows Y in figure 13. This translational movement causes the connection members 54a, b to pivot inwardly towards each other about the axles 74. In turn, the slots 57 are also moved towards each other which moves the levers members 35a, 35b towards each other, thus disengaging the rotor brakes of both motors 30a, 30b (see figures 12 and 13).

If a user desires to reapply the rotor brakes, the shaft 51 is simply rotated in the opposite direction until the moveable members again adopt the positions shown in figure 11 . Whilst in the above embodiments, the apparatus 10 includes a rotor brake actuation device 50 which engages or disengages both rotor brakes synchronously, embodiments are envisaged where two separate rotor brake actuation devices are provided. For example, as shown in figure 11 , then shaft 51 could be separated at plane Z into two separate shafts which could then be rotated independently. This may be advantageous where only one motor has malfunctioned or failed and where being able to apply forward/rearward drive to one wheel might be advantageous.

Embodiments are also envisaged where the apparatus includes only a single motor driving one or both (or more) wheels, e.g. via suitable gearing/differential. In such an embodiment, the apparatus may include a rotor brake actuation device of identical or similar construction/operation to that shown in the figures. For example, as shown in figure 11 , the rotor brake actuation device may include only the components to one side of the plane Z, but operate in substantially the same way, moving the lever member of the motor between its braked and unbraked conditions.

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.

Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.