GB2495484A

GB2495484A - Portable auxiliary drive unit for a wheeled load

Info

Publication number: GB2495484A
Application number: GB1117292.1A
Authority: GB
Inventors: Shahid Saleem; James Thomas Mason
Original assignee: Ferno UK Ltd
Current assignee: Ferno UK Ltd
Priority date: 2011-10-07
Filing date: 2011-10-07
Publication date: 2013-04-17
Also published as: GB201117292D0

Abstract

A portable auxiliary drive unit for wheeled loads, such as wheelchairs and stretchers, comprises drive means, e.g. a pair of independently driven wheels 12, and means 40,42 to engage and raise at the wheels at one end of the load off the ground so that the drive means can then be used to drive the load. Preferably, the drive unit has a ramp surface 40 that engages a cross member 104 of, for example, a stretcher. Movement of the drive unit towards the stretcher causes the cross bar 104 to travel up the ramp 40 whereupon it can be engaged in a recess 42. A hand-held control connected by a lead 38 is then used by an operative to drive the stretcher. Each driven wheel 12 of the power unit may include its own drive motor 32A, 32B. A pair of front wheels [16, Fig. 9] may be coupled to an actuator [52, Fig. 9] which causes the wheels to move towards/away from the drive wheels 12 of the drive unit, thus causing the front of the unit to dip or lift to assist in the coupling or uncoupling of the unit with the wheeled load.

Description

DRIVE UNIT

The present invention relates to a drive unit, a drive unit and a load and a method of operating a drive unit. The present invention is particularly, although not exclusively, applicable for a drive unit for a stretcher or wheelchair.

Stretchers are used to transport patients and they have a raised position, in which an upper frame is spaced from a lower frame in which operatives are able to pull the stretcher along, and a lowered position in which the upper frame is directly supported by the lower frame. In the lowered position the stretcher is more stable and it is generally in this position that the stretcher is occupied when located in an ambulance.

Driven stretchers are known. However these are expensive and the weight is considerable. This has a disadvantage when the stretcher has to be lifted in and out of ambulances. In addition, should the battery driving stretchers fail the extra weight to be pulled by the operatives is dangerous for the operatives.

It is an object of the present invention to attempt to overcome at least one of the above or other problems.

According to one aspect of the present invention a drive unit includes drive means arranged to drive the unit, the drive unit, in use, being arranged to cause a load supported by wheels at each end region to raise the or each wheel at one end region off the ground, the drive unit being arranged to be driven to drive the load with the drive means.

According to another aspect of the present invention a method of operating a drive unit and a load comprises causing the drive unit to raise the load so that the wheels at one end region of the load are raised off the ground with the other end region of the load being supported by at least one wheel and driving the load by the drive means.

According to one aspect of the present invention a drive unit includes a drive means arranged to drive the unit and an upwardly facing ramp whereby, in use, relative movement of the drive means towards a load supported by wheels at each end region is arrange to cause the or each wheel at one end of the load to be raised off the ground, the drive unit then being arranged to be driven to drive the load.

According to a further aspect of the present invention a drive unit and a load are provided in which the drive unit includes drive means arranged to drive the drive unit and an upwardly facing ramp whereby, in use, relative movement of the drive means towards the load is arranged to cause at least one wheel of the load at one end region of the load to be raised off the ground by engagement of the ramp with said one end region of the load with the drive unit then being arranged to drive the load, with the load being supported at the other end region of the load by at least one wheel.

Accordingly to a further aspect of the present invention a method of operating a drive unit and a load comprises causing relative movement of the drive unit and the load towards each other to cause an upwardly facing ramp of the drive unit to raise at least one wheel of the load at one end region off the ground by the load rising up the ramp at said one end region of the load and driving the load with the drive means of the drive unit, the load being supported at the other end region of the load with at least one wheel.

The present invention includes any combination of the herein referred to features.

The present invention is further defined in the claims.

The present invention can be carried into practice in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawings, in which: Figures 1 to 4 are a perspective, plan, side and rear view respectively of a drive unit 10; FigureS is an exploded view of the drive unit 10; Figure 6 is a plan view of the drive unit 10 engaged with the front of a load that may comprise a stretcher 100; Figure 7 is a section view of the front of the stretcher 100 with the drive unit along the line 7-7 of Figure 6; and Figure 8 is a perspective view of the drive unit 10 and the front of the stretcher 100; Figures 9 and 10 are side views of an additional embodiment showing the drive unit 10 in a raised and a lowered position respectively.

As shown in Figure 8, the drive unit 10 supports the front 102 of a load such as a stretcher 100. The drive unit 10 includes steering means that such as comprise driven steering means such as wheels 12 that may be driven.

In use, the drive unit is driven to cause the stretcher to move forwards or backwards or around a bend or any combination thereof.

The drive unit includes a housing 14 that supports the spaced, forward driven wheels 12, a rear support such as a rotatable support that may be a rotatable wheel that may be a freely rotatable wheel such as a pair of wheels 16 mounted on a common axle 18.

The housing may include at least one handle and preferably includes two handles 20 and 22 which allow an operative to manoeuvre or lift the drive unit manually, possibly off the ground to port the drive unit.

The drive unit 10 includes a power source that may comprise a battery 24 which may be located in the housing 14.

The housing 14 may support the battery 24, the driven wheels 12 and the freely

rotatable wheels 16.

The housing 14 may include a lower housing part 26 and an upper housing part 28.

The freely rotatable wheels are attached to the underside of the lower housing pait 26 and the battery is supported on the upper surface 30 of the lower housing part 26.

Each driven wheel 12 may be supported on the lower housing part 26 and may have its own power source that may comprise a drive motor 32A, 32B. Each drive motor 32A, 32B drives its associated driven wheel 12 through a gear mechanism 34A, 34B. A bearing (not shown) of each driven wheel is supported by the lower housing.

The drive unit 10 also includes a control 36 which may effect the drive of the drive unit.

The upper housing part 28 is attached to the lower housing part by means (not shown).

Operation of the drive unit will now be described.

The drive unit may receive a command from a controller which may be a remote control that may be hand-held and that may transmit a command such as by radio communication or the remote control may comprise a hand-held control, connected to the drive unit by a cable 38.

The drive unit is then manoeuvred and driven such that the rearward upper surface 40, which may be provided on the housing 14, approaches a cross member 104 of the stretcher 100. The upper surface 40 of the drive unit is inclined such that the surface 40 comprises a ramp that first engages with the cross member 104 and, upon further driving of the drive unit 104 under the cross member, then raises the cross member and thereby raises the front wheels 106 of the stretcher off the ground.

Further driving of the drive unit 10 under the cross member 104 results in the cross member 104 engaging with the drive unit such as by the cross member resting in a recess 42 of the drive unit 10. The cross member is thereby constrained to move as one with the drive unit and is not able to rotate relative to the drive unit. Furthermore, the cross member may be the same length or slightly longer than the length of the recess 42 such that there can be no or little side to side relative movement of the recess and cross member.

The ramp and the recess 42 are arranged such that the front wheels 106 of the stretcher remain off the ground when the drive unit and the stretcher are engaged.

The rear wheels of the stretcher are engaged. The rear wheels of the stretcher still provide support.

The control 36 can then receive a command to drive the drive unit, forwardly, rearwardly or around a bend with the motors 32A and 32B being separately controlled. For instance to drive the stretcher forwardly both motors drive the wheels 12 in the same direction at the same rate. To power the stretcher around a bend one motor may drive its associated wheel at a greater rate than the other motor with both motors driving their associated wheels in the same direction or with one wheel being stationary such as by being held stationary by its associated motor or by the wheels being driven in alternate directions which may be driven at different rates in alternative directions.

The slope of the ramp 40 may be such that the stretcher does not have to be held to stop it moving rearwardly as the drive unit is being driven into engagement with the stretcher, for instance the slope may be less than 20° or less than 150 or in the region of 5° in the horizontal.

The recess 42 is such that less than half of the cross member 104 may be surrounded for instance in the region of a third only of the surface of the cross member may be surrounded. Alternatively or additionally the recess may comprise a curve or arcuate recess that may extend through less than 180° or less than 160° or in the region of 120°. Alternatively or additionally, at least one forward or rearward facing exit from the recess may be curved such as by an arcuate curve. This allows engagement or disengagement of the cross member with the recess to be smooth with a reduction in shock movement to any patient on the stretcher.

To disengage the stretcher from the drive unit the stretcher may be held still and the drive unit 10 may be driven away from the stretcher. Alternatively or additionally the stretcher may be pulled or pushed rearwardly. Alternatively or additionally the front handle 22 may be pulled forwardly. Alternatively or additionally the front handle may be raised to lift the drive wheels 12 off the ground. The drive wheels 12 may be forward of the stretcher front wheels 106 and the wheels 16 may be rearward of the wheels 106. From Figure 7 it can be seen that the wheels 106 are only a short distance off the ground. The drive wheels 12 may be driven forwardly up a ramp (not shown) to cause the wheels 106 to engage with the ground to assist in or cause disengagement possibly without an operator having to pull or push or lift any part of the drive unit or stretcher. Any combination of the above may be used to effect disengagement. The drive wheels 12 may be held against rotation during disengagement. The drive wheels may be driven during disengagement.

The stretcher descends the ramp 40 to allow the stretcher to be lowered gently to the ground once the cross member 104 is disengaged from the recess 42.

The rearwardly facing side surfaces 46 of the ramp 40 diverge rearwardly and outwardly to assist in the alignment of the drive unit 10 with the stretcher. For instance, one of the side surfaces may abut with an upright member (not shown) of the stretcher which may support the cross member 104 such that, with or without the front wheels 106 being off the ground relative movement of the drive unit towards engagement with the stretcher may cause relative sideways movement of the stretcher and the drive unit. The side surfaces 46 may be at an angle to the vertical and may be curved.

The cross member 104 may comprise a handle for the stretcher which can assist in an operative manoeuvring the stretcher when the stretcher is in the raised position.

The embodiment shown in Figure 9 can operate as previously described.

However, the wheels 16 are pivotally mounted above a horizontal axis 50. An actuator 52 which may be hydraulic, pneumatic or electrically drive, is shown in dashed tines. The actuator cooperates with the housing 54 from which the wheels 16 depend at a location spaced from the axis 50.

Retraction of the actuator causes the housing 54 and thereby the wheels 16 to move upwardly and reawardly relative to the drive wheels 12 to cause the housing to dip down as shown in Figure 10.

This dipping movement may assist in locating the cross number 104 in the recess 42. For instance, less force may be needed to allow the cross member 42 to rise over the forward edge 56 into the recess 42. Alternatively, the height of the edge 56. when dipped, may be the same as or lower than the lower edge of the cross member 104.

The height of the reward edge 58 of the recess may be greater than the height of the lower edge of the cross member 104. Consequently the cross member 104 may abut the reaward edge to ensure that the two parts are aligned. Alternatively the operator may observe when the two parts are aligned. When the unit is positioned correctly beneath the cross member 104 the actuator may be activated to move the wheels downwardly and forwardly back to the position shown in Figure 9. This movement raises or further raises the cross member 104 to lift the front of the stretcher off the ground. The unit then operates as previously described. The unit 10 has all of the same features as previously described in addition to the operation of the ramp and thus may offer two alternatives for raising the front of the stretcher.

The actuator may be the activated by the controller as previously described.

Whilst the drive unit has been described as driving the stretcher in the lowered position alternatively or additionally the drive unit may engage with the stretcher such as by engaging with a cross member of the stretcher when the stretcher is in a raised position to drive the stretcher in the raised position or the drive unit may drive a stretcher or patient support that is not able to be raised or lowered.

Furthermore, whilst the drive unit has been described as driving a stretcher it will be appreciated that the drive unit could engage with any load having forward and rearward wheels that support a load with engagement of the drive unit raising the front wheels off the ground. Such a load may comprise a load supporting a person such as a wheelchair, in which case the power unit may engage with a cross bar of the wheelchair.

Whilst the present invention has been described as lifting the front of a load it will be appreciated that the rear of the load could easily be supported and accordingly when the front is referred to herein it covers and is interchangeable with lift the rear of the load.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

<claim-text>CLAIMS1. A drive unit including drive means arranged to drive the uit, the drive unit, in use, being arranged to cause a load supported by wheels at each end region to raise the or each wheel at one end region off the ground, the drive unit then being arranged to be driven to drive the load with the drive means.</claim-text> <claim-text>2. A drive unit as claimed in claim 1 in which the drive means comprise a pair of spaced drive members.</claim-text> <claim-text>3. A drive unit as claimed in claim 2 in which each of the drive members are operable separately from each other.</claim-text> <claim-text>4. A drive unit as claimed in claim 3 including two drive members, one for each drive member.</claim-text> <claim-text>5. A drive unit as claimed in claims 2 to 4 in which each drive member is arranged to be driven in a first direction and a second, opposite direction.</claim-text> <claim-text>6. A drive unit as claimed in claims 1 to 5 including control means arranged to control the drive means.</claim-text> <claim-text>7. A drive unit as claimed in claims I to 6 including the drive means comprise drive wheels.</claim-text> <claim-text>8. A drive unit as claimed in any preceding claim including a hand-held control arranged to control the drive means.</claim-text> <claim-text>9. A drive unit as claimed in claim 8 in which the hand-held control is connected via a cable.</claim-text> <claim-text>10. A drive unit as claimed in claim 8 in which the hand-held control comprises a remote control arranged to transmit a signal to control the drive means.</claim-text> <claim-text>11. A drive unit as claimed in any preceding claim including engagement means arranged, in use, to engage with a load when the or each wheel of a load has been raised off the ground.</claim-text> <claim-text>12. A drive unit as claimed in claim 11 in which the engagement means include a recess on an upwardly facing surface of the drive unit.</claim-text> <claim-text>13. A drive unit as claimed in claim 12 in which the recess extends across the drive unit.</claim-text> <claim-text>14. A drive unit as claimed in claim 12 or 13 in which the recess is curved.</claim-text> <claim-text>15. A drive unit as claimed in claims 12 to 14 in which the recess is arcuate.</claim-text> <claim-text>16. A drive unit as claimed in claims 12 to 15 in which the recess extends through less than 160°.</claim-text> <claim-text>17. A drive unit as claimed in any preceding claim including an upwardly facing ramp whereby, in use, relative movement of the drive unit towards a load is arranged to cause the or each wheel at said one end region to be raised off the ground by the load riding up the ramp.</claim-text> <claim-text>18. A drive unit as claimed in claim 17 and any of claims 12 to 15 in which a surface that extends from the ramp to the recess is curved.</claim-text> <claim-text>19. A drive unit as claimed in claim 18 in which the surface that extends from the ramp to the recess is curved in the opposite direction to that of the recess.</claim-text> <claim-text>20. A drive unit as claimed in claim 17 and any of claims 18 or 19 in which the ramp extends outwardly.</claim-text> <claim-text>21. A drive unit as claimed in claim 20 in which the angle of the ramp in the hoiizontal is less than 30° or less than 20° or 10°.</claim-text> <claim-text>22. A drive unit as claimed in any preceding claim in which the drive unit is portable by being lifted manually.</claim-text> <claim-text>23. A drive unit as claimed in any preceding claim in which the drive unit includes at least one wheel spaced from the drive wheels arranged to assist in supporting the drive unit.</claim-text> <claim-text>24. A drive unit as claimed in claim 22 in which the at least one wheel spaced from the drive unit is arranged to be at least partly co-extensive with a wheel of a load that has been lifted off the ground when viewed from the side.</claim-text> <claim-text>25. A drive unit as claimed in claims 22 or 23 in which the at least one wheel is pivotally mounted about an upwardly extending axis.</claim-text> <claim-text>26. A drive unit as claimed in any preceding claim including an actuator whereby, in use, when at least a part of the drive unit is located to under a part of the load the actuator is activated to cause at least a part of the load to be raised to cause the or each wheel at said one end region to be raised off the ground.</claim-text> <claim-text>27. A drive unit as claimed in claim 26 when dependent on any preceding claim including claim 23 in which at least one of said wheels is mounted on a portion that is movable between a lowered position and a raised position in which, in the raised position, at least part of the drive unit is at a greater elevation than that part is when the portion is in the lower position.</claim-text> <claim-text>28. A drive unit as claimed in claim 27 in which the portion is pivotally mounted on the drive unit about an axis extending at an angle to the vertical.</claim-text> <claim-text>29. A driver unit as claimed in claim 28 in which the axis is horizontal.</claim-text> <claim-text>30. A drive unit as claimed in any of claims 27 to 29 in which the or each wheel that is mounted on the portion has a diameter that is less than the diameter of the other spaced wheel.</claim-text> <claim-text>31 A drive unit and a load, the drive unit including drive means and means to cause a load supported by wheels at each end region to be raised off the ground at one end region, the drive unit then being arranged to drive the load with the drive means.</claim-text> <claim-text>32. A drive unit and a load as claimed in claim 31 in which the drive unit includes an upwardly facing ramp where, in use, relative movement of the drive means towards the load is arranged to cause at least one wheel of the load at one end region to be raised off the ground by engagement of the ramp with said one end region of the load with the load being supported at the other end region of the load by at least one wheel.</claim-text> <claim-text>33. A drive unit as claimed in claims 31 or 32 including an actuator whereby, in use, when at least part of the drive unit is located under a part of the load the actuator is activated to cause at least part of the load to be raised to raise the or each wheel at said one end region of the ground.</claim-text> <claim-text>34. A drive unit and load as claimed in any of claims 31 to 33 in which the load and drive unit are arranged to be engaged when the at least one wheel is raised off the ground.</claim-text> <claim-text>35. A drive unit and a load as claimed in any of claims 31 to 33 in which the drive unit includes at least two wheels spaced from each other in a direction between their rotational axes.</claim-text> <claim-text>36. A drive unit and load as claimed in claim 35 in which the at least one wheel of the drive unit is co-extensive with at least one wheel of the load when the at least one wheet of the toad is raised off the ground, when the load and drive unit are viewed from the side.</claim-text> <claim-text>37. A drive unit and load as claimed in any of claims 35 or 36 in which the axes of at least two wheels are arranged either side of where the load is supported by the drive means.</claim-text> <claim-text>38. A drive unit and load as claimed in any of claims 31 to 37 in which the drive unit is as claimed in any of claims ito 30.</claim-text> <claim-text>39. A method of operating a drive unit and a load comprising causing the drive unit to raise the load so that the wheels at one end region of the load are raised off the ground with the other end region of the load being supported by at least one wheel and driving the load by the drive means.</claim-text> <claim-text>40. A method as claimed in claim 30 in which an upwardly facing ramp of the load is moved relative to the load towards the load to cause the wheel or wheels at said one end region to be raised off the ground by the load riding up the ramp.</claim-text> <claim-text>41 A method as claimed in claim 39 or 40 in which the drive unit includes an actuator and when at least part of the drive means is located under at least part of the load the actuator is activated to raise at least part of the drive means upwardly thereby raising the or each wheel at said one end region off the ground.</claim-text> <claim-text>42. A method of operating a drive unit and a load as claimed in any of claims 39 to 41 comprising controlling the drive means of the drive unit with a hand-held control.</claim-text> <claim-text>43. A method of operating a drive unit and a load as claimed in claim 31 or 32 comprising causing the drive unit to engage with the load by movement of the drive unit and load towards each other.</claim-text> <claim-text>44. A method of operating a drive unit and a load as claimed in claim 40 or any claim when dependent on claim 40 comprising causing the drive unit to engage within a recess towards a top region of the ramp.</claim-text> <claim-text>45. A method of operating a drive unit and a load as claimed in any of claims 39 to 44 comprising causing the drive unit and load to engage such that relative pivotal movement of the load and drive unit is prevented.</claim-text> <claim-text>46. A method of operating a drive unit and a load as claimed in any of claims 39 to comprising causing the drive unit and the load to engage such that relative transverse movement of the load and the drive unit is prevented.</claim-text> <claim-text>47. A method of operating a drive unit and a load as claimed in any of claims 39 to 46 in which the drive unit is driven by at least one wheel of two wheels of the drive unit that are spaced from each other in the direction between their rotational axes.</claim-text> <claim-text>48. A method of operating a drive unit and a load as claimed in claim 47 in which the drive unit comprises causing at least one wheel of the drive means to be at least partially co-extensive with at least one raised wheel of the load when viewed from the side.</claim-text> <claim-text>49. A method of operating a drive unit and a load as claimed in claim 47 or 48 comprising driving at least the wheel that is furthest from the other end region of the load that is supported by at least one wheel when said one region of the load is raised.</claim-text> <claim-text>50. A method of operating a drive unit and a load as claimed in any of claims 31 to 39 comprising supporting the end region of the load at a location between the rotational axes of said wheels of the drive unit.</claim-text> <claim-text>51. A method of operating a drive unit and a load as claimed in any of claims 39 to comprising causing the drive unit and the load to move towards each other to raise the at least one wheel of the load and also causing the load and the drive unit to cooperate with each other such that they move laterally relative to each other should they be misaligned.</claim-text> <claim-text>52. A method of operating a drive unit and a load as claimed in claim 40 or any claim when dependent on claim 40 comprising driving the drive unit with the drive means to cause the at least one wheel of the load to be raised up the ramp.</claim-text> <claim-text>53. A method of operating a drive unit and a load as claimed in claim 40 or any claim when dependent on claim 40 to 52 comprising lowering the at least one wheel of the load onto the ground by raising one end of the drive unit to increase the angle of the ramp to the horizontal and causing the load and drive unit to move away from each other.</claim-text> <claim-text>54. A method of operating a drive unit and a load as claimed in claim 41 or any claim dependent on claim 41 comprising lowering a part of the drive unit to return the or each wheel at said one end region of the load back onto the ground.</claim-text> <claim-text>55. A method of operating a drive unit and a load as claimed in any of claims 39 to 54 comprising manually lifting the drive unit.</claim-text> <claim-text>56. A method of operating a drive unit and a load as claimed in any of claims 39 to using the drive unit as claimed in any of claims ito 31.</claim-text> <claim-text>57. A method of operating a drive unit and a load as claimed in any of claims 39 to comprising operating the load and drive unit as claimed in any of claims 32 to 38.</claim-text>