GB2581302A - Disability vehicle hoist - Google Patents

Abstract

A carrier vehicle 12 has a hoist 2 for lifting a disability vehicle into the carrier vehicle 12, the hoist 2 having a support arm 4 for supporting the weight of the disability vehicle, a four-bar linkage 16, and a linear actuator 18. The support arm 6 is mounted to the carrier vehicle to rotate about a vertical axis, and the linear actuator assembly 18 actuates the four-bar linkage 16 to rotate the support arm 4 to swing into/out of the carrier vehicle 12. A second body 16b of the linkage does not rotate with respect to the carrier vehicle 12, and a first body 16a is V-shaped. The linear actuator 18 has an electric motor 20 and hand-held controller.

Description

DISABILITY VEHICLE HOIST

The present invention relates to a hoist apparatus for lifting a disability vehicle into a carrier vehicle, such as a car or van.

In our current society, technology is often used to assist those who suffer disabilities. One example of this is the rise in usage of disability vehicles such as disability scooters or buggies (often referred to as short distance mobility vehicles). These devices allow those that would otherwise be immobile or have difficulties with mobility to take part in everyday life. Disability vehicles are relatively heavy, typically weighing between 75 kg to 125 kg. There are many manufacturers of such disability vehicles, including Sunrise Medial of Fresno California, and Prestige Mobility of Bangor, Wales. Since these vehicles are intended for limited range transport only, for longer journeys it is still necessary to transport the disabled person in a car or other carrier vehicle. Such carrier vehicles may have modifications made to them to allow the disabled person to drive them, such as the fitting of hand controls rather than foot pedals etc. When the disabled person gets to their destination, it is desirable for them to have the use of their disability vehicle at the destination. Thus there is a requirement to transport the disability vehicles in the vehicle with the disabled person. However, because of the weight of such scooters, it is beyond the safe weight for a person to safely lift into the carrier vehicle, and certainly beyond the range that the disabled person is likely to be able to lift. Thus there are a range of hoists for disability vehicles available on the market to allow the automated lifting of disability vehicles into and out of carrier vehicles. Such systems have been available for many years, such as those made by the applicant, Brig-Ayd Controls Ltd of Welwyn Garden City, England, and by AutoChair Ltd of Kirkaldy, Fife, Scotland.

One such system is described in GB 2423294 A and is illustrated in Figure 1. The hoist 2 includes of a 'crane like' lifting arm 6, the base of which is fitted securely to the structure of the carrier vehicle 12. Typically the lifting arm 6 is pivotally moved by electric motors powered, for example, by the battery of the carrier vehicle 12. To use the hoist 2, the lifting arm 6 is swung out of the back of the carrier vehicle 12, which is usually an estate-style car or a hatchback, into a first lifting position. The lifting arm 6 is lowered down by a telescopic actuator arm 8, and the disability vehicle 10 is attached to the end of the lifting arm 6. The lifting -2 -arm 6 is lifted back up to raise the disability vehicle 10 to a height above the ground sufficient to allow the disability vehicle 10 to be loaded into the carrier vehicle 12 and the lifting arm 6 is then swung back into the carrier vehicle 12 to a second lifting position. In the second lifting position, the disability vehicle 10 is lowered onto the floor of the carrier vehicle 12. During transit, the disability vehicle 10 is not normally detached from the lifting arm 6 as it is often not easy to attach or detach the disability vehicle 10 in situ, particularly for a person with limited mobility.

Problems that occur in the above system are known. In many cases the carrier vehicle used will be the 'family' car, used also by healthy members of the family, rather than just for the transportation of the disabled person. It is therefore desirable that the hoist does not interfere with the normal usage of the carrier vehicle, so as to avoid the need to purchase a larger or more expensive vehicle than would otherwise be required. However, the operation of the hoist still needs to be simple and one should not have to be a skilled crane driver or mechanic to operate such a system.

The present invention therefore provides a hoist apparatus for lifting a disability vehicle into a carrier vehicle; the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle, the support arm being pivotally moveable from a first rotational position for deploying the disability vehicle onto the ground, through a second rotational position for stowing the disability vehicle within the carrier vehicle, to a third rotational position for stowing the lifting arm within the carrier vehicle, the first, second and third rotational positions being different; and a first rotation limiting means configured to prevent the lifting arm from pivoting beyond the second rotational position, the first rotation limiting means including an override to disable the first rotation limiting means responsive to an override condition being met so that the lifting arm can rotate to the third rotational position.

The rotation limiting means ensures simple operation of the hoist when loading the disability vehicle into the carrier vehicle, whilst minimising the impact of the hoist when the carrier vehicle is used for purposed other than transporting the disability vehicle.

When loading the disability vehicle, the rotation limiting means stops further rotation of the hoist once it reaches the second position within the carrier vehicle. In that position, the disability vehicle can be lowered safely into the back of the carrier vehicle. The second position is selected, typically during installation, so as -3 -to avoid the disability vehicle contacting, for example, the back of the rear seats or the sidewalls of the carrier vehicle. Accordingly, the position limiting means allows simple operation of the hoist because a user simply rotates the hoist to its maximum rotational position (the second position, when the rotation limiting means is not overridden) and lowers the hoist. There is thus no complex control required to manoeuvre the disability vehicle sufficiently far into the carrier vehicle, whilst simultaneously avoiding impact between the disability vehicle and the interior of the carrier vehicle. This is important as even minor impacts can damage either the carrier vehicle or the disability vehicle.

It has been found, however, that in the second position the hoist can obstruct the rear view of the driver of the carrier vehicle. The second position is dictated by the size and shape of the space within the carrier vehicle and the size and shape of disability vehicle, and typically cannot be changed. Accordingly, this obstruction is unavoidable whilst the disability vehicle is being transported.

However, in accordance with the hoist apparatus described herein, when the carrier vehicle is not being used to transport the disability vehicle, the first position limiting means can be overridden to allow the hoist to be rotated beyond the second position and into a stowed position. Thus, the obstruction caused by the hoist can be minimised when the carrier vehicle is being used for other purposes.

In certain embodiments, the hoist apparatus may include a load sensor for sensing a load carried by the lifting arm. The override condition may then be that the lifting arm is carrying below a threshold load.

The load carried by the arm is indicative of whether the disability vehicle is being carried by the hoist. Thus, in this embodiment, the override may be automatic and will allow the hoist arm to be further rotated, beyond the second position, when the disability vehicle is not being carried. In some embodiments, the first limiting means is completely overridden when the hoist is carrying below the threshold load such that the hoist arm does not stop in the second position but freely rotates through it, i.e. without the need for input from the user.

Although any suitable threshold may be selected, the threshold load would typically be less than 75 kg (although higher thresholds may be used where the hoist is intended for lifting larger disability vehicles). This ensures that the threshold is below the expected weight of the disability vehicle so that the override is not inadvertently actuated when the disability vehicle is loaded. Preferably the threshold is some way below the expected load of the disability vehicle (e.g. less -4 -than 40kg) so that even if the disability vehicle is for some reason lighter, e.g. if the battery is removed, the override is still not activated.

In an alternative embodiment, the override condition may be the receiving of a manual input from a user to override the first rotation limiting means.

This may take various forms, for example a lever on the hoist, or the like.

This manual input allows a user to decide specifically when to override the rotation limiting means.

In one arrangement, the lifting arm is rotatable responsive to a user actuating a control, such as a button on a controller, and the first rotation limiting means stops further rotation of the lifting arm responsive to the lifting arm reaching the second rotational position. The actuating of the control may include, for example, a single press of the control or continuously holding of the control. The manual input to override the first rotation limiting means can then be the user releasing the control and re-actuating the control when the lifting arm is in the second rotational position.

Such an arrangement is simple and intuitive to operate and does not add additional complexity to the controller for the hoist.

In further embodiments, the manual override may be combined with the load sensor discussed above such that the manual override is only effective when a load of less than the threshold load is being carried by the hoist arm.

The hoist apparatus preferably further comprises a second rotation limiting means configured to prevent the lifting arm from rotating beyond the third rotational position. Similar to as discussed above, the provision of a second rotation limiting means ensures simple operation of the hoist because, when the first rotation limiting means is overridden, the use simply rotates the hoist to its maximum position, which in this case is then the third position.

Preferably, the lifting arm is rotatable by an electric motor and the rotation limiting device prevents the lifting arm from pivoting beyond the second rotational position by stopping supply of electricity to the electric motor.

The use of an electric motor, rather than for example a mechanical rotation limiter, allows for the second position to be easily set when the hoist is installed into the vehicle.

Preferably the hoist further comprises a four-bar linkage and a linear actuator arrangement, wherein the support arm is connected to a first body of the linkage, the first body being adapted to be connected to a second body of the -5 -linkage which, in use, does not rotate with respect to the carrier vehicle; and wherein the linear actuator is arranged to actuate the four bar linkage to rotate the support arm. The linear actuator may comprise the above mentioned electric motor.

By the above arrangement the support arm can be rotated so as to align with the forward-rearward direction of the carrier vehicle using a linear actuator assembly that also extends approximately in the forward-rearward direction. This in turn allows the hoist to be positioned closer to the sidewall of the carrier vehicle because the actuator arrangement does not need to be positioned between the hoist and the sidewall of the carrier vehicle, thus minimising obstruction of the rearward view of a driver of the carrier vehicle.

Indeed, this arrangement is not limited to the above specified hoist and thus, viewed from another aspect, the present invention can be seen to provide a hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle; a four-bar linkage; and a linear actuator arrangement, wherein the support arm is connected to a first body of the linkage, the first body being adapted to be connected to a second body of the linkage which, in use, does not rotate with respect to the carrier vehicle; and wherein the linear actuator is arranged to actuate the four bar linkage to rotate the support arm.

In some embodiment, the first body of the linkage may have a V-shape comprising two diverging legs, a first of the legs including the connection to the support arm and the pivotal connection to the second linkage.

This V-shaped body allows the support arm 4 to be rotated further than would have been possible with a straight body, thus further reducing obstruction of the rearward view of a driver of the carrier vehicle.

The hoist preferably comprises a lifting arrangement for lifting the disability vehicle, wherein the lifting arrangement comprises: a motor-driven spool about which is wound a lifting line, and the lifting arrangement is mounted to the support arm such that, when the support arm is installed in a carrier vehicle, the rotational axis of the spool is substantially horizontal, wherein the lifting arrangement further comprises a guide member located such that, in use, when the line is unwound from the spool, the line passes from the spool and over the guide member; and wherein the guide member is located such that, in use, a top surface of the guide member is vertically higher than the level of a bottom surface of the spool. -6 -

This lifting arrangement assembly is contrary to the conventional arrangement of such motor-driven lifting arrangement, in which the lifting line would be allowed to run approximately vertically downward. This configuration effectively allows an attachment at the end of the line to be lifted higher than in those previous configurations. This provides two main advantages.

The first is that, when the carrier vehicle is used for purposes other than the transport of the disability vehicle, having the attachment as high as possible minimises obstruction of the rearward view of the driver of the carrier vehicle. Secondly, the ability to raise the attachment even slightly higher allows either a larger disability vehicle to be moved through the opening of the carrier vehicle, or a disability vehicle of a given size to be loaded into a carrier vehicle having a smaller opening.

Indeed, this lifting arrangement gives rise to such advantages even without the use of the position limiting means discussed above. Thus, viewed from another aspect, the present invention may also be seen to provide a hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle; and a lifting arrangement for lifting the disability vehicle, the lifting arrangement comprising a motor-driven spool about which is wound a lifting line, and the lifting arrangement being mounted to the support arm such that, when the support arm is installed in a carrier vehicle, the rotational axis of the spool is substantially horizontal, wherein the lifting arrangement further comprises a guide member located such that, in use, when the line is unwound from the spool, the line passes from the spool and over the guide member; and wherein the guide member is located such that, in use, a top surface of the guide member is vertically higher than the level of a bottom surface of the spool.

The hoist apparatus may comprise an attachment for attaching the line to the disability vehicle. This may for example be a hook or similar. Advantageously, the hoisting apparatus may enable the attachment to be lifted, when the line is fully retracted, to a position higher than if the guide member were not located at the specified higher level.

Preferably the guide member is located such that, in use, an upper part of the lifting line as it passes over the guide member is below the level of a top surface of the spool. The reason for this is that if the line passes above this level then the whole apparatus must be mounted lower in its carrier vehicle in order to avoid -7 -interference with the roof of the vehicle. This means that the advantage of increased lifting height for the attachment/disability vehicle will not be increased when the guide member is moved higher than that point.

The present invention may also be seen to provide a carrier vehicle comprising a hoist apparatus in accordance with either or both aspects as discussed above. In a carrier vehicle with a hoist apparatus as in the first aspect the lifting arm preferably obstructs the rear view of a driver of the carrier vehicle less in the third position than in the second position.

Certain preferred embodiments of the present invention will now be described in greater detail by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a schematic view showing an exemplary hoist; Figure 2A and 2B show a four-bar linkage arrangement for rotating the hoist in accordance with an embodiment of the present invention; Figures 3A to 30 show plan views of the hoist installed in a vehicle illustrating an embodiment of the present invention; Figure 4 is a schematic view showing an alternative exemplary hoist; Figure 5A shows a prior art arrangement of a lifting motor; and Figure 5B shows the arrangement of the lifting motor in accordance with another embodiment of the present invention.

Figure 1 shows a hoist 2 for loading and unloading a disability vehicle 10, into and out of carrier vehicle 12 through an opening of the carrier vehicle 12, such as a door or hatchback. For simplicity, the present invention will be described with reference to the hoist described in GB 2423294 (illustrated in Figure 1). However, it should be understood that the present invention is not limited to this hoist, but is applicable to many other pivotal hoist arrangements. A further example of a pivotal hoist 102 is shown in Figure 4 and will be discussed in greater detail below.

The hoist 2 comprises a support member 4, which is mounted to the carrier vehicle 12 in a vertical orientation, for example by bolting mounting plates 5a, 5b to a side wall inside the carrier vehicle 12. The mounting plates 5a, 5b extend from the upper and lower ends of the support arm 4 respectively. The support member 4 is configured in such a way as to allow it, and the body of the hoist 2 attached to it, to rotate about a vertical axis. A lifting arm 6 is mounted to the end of the support member 4 adjacent the floor of the carrier vehicle so as to be pivotable about a horizontal pivot axis extending parallel to the side wall of the carrier vehicle. -8 -

The lifting arm 6 comprises an upwardly extending arm terminating in a suitable attachment, shown schematically at 14, for holding the disability vehicle 10. The attachment 14 may, for example, comprise slings that can be attached around the disability vehicle 10, which are connected to a 'spreader bar', which is in turn attached to the end of the lifting arm 6. The attachment of the spreader bar to the lifting arm 6 is usually permanent, as it is highly undesirable for the disability vehicle to fall off the hoist 2; the weight of the disability vehicle 10 could cause substantial damage to the carrier vehicle 12 and/or persons involved. An alternative attachment 14 may include, for example, a hook 24 (shown in Figures 5A and 5B) for engaging a corresponding eye on the disability vehicle 10.

The hoist 2 further comprises a lifting arrangement 8 for lifting the disability vehicle 10 via the attachment 14. The lifting arrangement 8 may include, for example, a telescopic actuator arm having one end pivotally attached to the upper end of the lifting arm 6 and the other end pivotally attached to the support member 4 at a point vertically above the lower end of the support member 4. The actuator arm acts to pull the upper end of the lifting arm 6 towards the support member 4 when the actuator arm is retracted, so as to pivot the lifting arm 4 upwardly (in the clockwise direction as seen in Figure 1) thus raising the disability vehicle 10. When the actuator arm is extended, it ads to push the upper end of the lifting arm 6 away from the support member 4 so as to pivot the hoist arm 10 downwardly On the anticlockwise direction as seen in Figure 1) thus lowering the disability vehicle 10. Figures 2A and 28 show a four-bar linkage arrangement 16 for rotating the support arm 4 of the hoist 2 during operation. A four-bar linkage comprises four rigid bodies (also known as links) connected in a loop by four pivotal joints so that the bodies move in parallel planes.

The support arm 4 of the hoist is connected at its lower end to a first body 16a of the linkage 16, so as to rotate with the first body 16a. The first body 16a is pivotally connected to a second body 16b of the linkage 16.

The second body 16b of the linkage 16 is mounted to the carrier vehicle 12 so as not to rotate relative to the carrier vehicle 12. The axis of the second body 16b (i.e. the direction between the pivotal connections to the second and fourth bodies 16b, 16d) is substantially aligned with a forward-rearward direction of the carrier vehicle 12.

In some arrangements, the second body 16b may not be provided as part of the hoist 2 but may instead be provided by the body of the carrier vehicle 12, for -9 -example the first body 16b may be pivotally connected to one location on the carrier vehicle 12 and the third body 16c may be pivotally connected to another location on the carrier vehicle 12. This does not affect the operation of the linkage 16.

The second body 16b is pivotally connected to a third body 16c of the linkage, which is in turn pivotally connected to a fourth body 16d of the linkage 16, which is in turn pivotally connected to the first body 16a.

A linear actuator assembly 18 controlled by an electric motor 20 is arranged so as to actuate the four-bar linkage 16. The actuator assembly 18 is connected at one end to the second body 16b (this could be via carrier vehicle 12) and at the other end to the pivotal connection between the third body 16c and the fourth body 16d.

It will be apparent that the actuator may be connected instead to the third or fourth bodies directly, and the invention is not limited to specific connection location. That is to say, the actuator assembly 18 must simply be arranged so as to actuate the four-bar linkage 16 by rotating the third body 16c with respect to the second body 16b.

The actuator assembly 18 is shown in a retracted configuration in Figure 2A and in an extended configuration in Figure 2B. As can be see, when the actuator assembly 18 extends, the hoist 2 is rotated from a position within the carrier vehicle 12 towards a position extending out of the carrier vehicle 12.

As can be seen from the drawings, the first body 16a is approximately "V-shaped", i.e. having two diverging legs (preferably separated by between 45° and 135°). The first leg is pivotally connected to the second body 16b and the second leg is connected to the fourth body 16d. The support arm 4 of the hoist 2 is connected to the leg of the second body 16b that connects to the second body 16b.

By this configuration, in the retracted configuration, the first leg can extend substantially parallel with the first body 16a, whilst the second leg extends away from the first body 16a to provide a moment arm. This V-shaped body thus allows the support arm 4 to be rotated further than would have been possible with a straight body. Also, the moment arm increases the torque applied to the support arm 4, particularly when moving it from the retracted position.

By the above arrangement the support arm 4 can be rotated so as to align with the forward-rearward direction using an actuator assembly 18 that also extends approximately in the forward-rearward direction. This in turn allows the hoist 2 to be positioned closer to the sidewall of the carrier vehicle 12 because the actuator -10 -arrangement 18 does not need to be positioned between the hoist 2 and the sidewall of the carrier vehicle 12, thus minimising obstruction of the rearward view of a driver of the carrier vehicle 12.

The hoist 2 includes movement limiters to simplify operation of the hoist 2.

A rotation limiter is used to stop further rotation of the hoist 2 once it reaches a position within the carrier vehicle 12 that the disability vehicle 10 can be lowered safely into the back of the carrier vehicle 10, thus prevent the disability vehicle 10 from hitting, for example, the back of the rear seat of the carrier vehicle 12. The rotation limiter is important, as some parts of disability vehicles 10 are relatively fragile, such as plastic mudguards. Even only minor impacts with rigid surfaces can crack or otherwise damage these plastic items. Furthermore, contact between a rigid part of the disability vehicle 10, such as the wheels, with the back of the back seats (or any other predominantly vertical planes) can cause damage to occur to the vehicle linings or trim. This in turn diminishes the resale value of the carrier vehicle 12.

Thus, the rotation limiter allows an operator to simply pivot the hoist 2 between its maximum positions to load or unload the disability vehicle 10 without fear of contact between the carrier vehicle 12 and the disability vehicle 10 (when in its fully lifted position). Therefore, the disability vehicle 10 can be easily loaded or unloaded without risk of causing damage to the carrier vehicle 12 or to the disability vehicle 10, even when the safe operational margins are small.

Similarly, the hoist 2 may include a vertical lifting limiter to prevent further lifting by the lifting arrangement 8 when a maximum lifting position limit is reached. This limiter allows the operator to simply actuate the lifting arrangement 8 until it reaches its maximum lift position, in which the hoist 2 will not, for example, contact the roof of the carrier vehicle 12 when being rotated between the lifting positions. In the present embodiment, the hoist 2 is rotated about the vertical axis by an electric motor 20 and the lifting arrangement 8 is actuated by another electric motor (not shown). The rotation limiter and lifting limiter may therefore be implemented electronically by stopping the respective electric motor from further movement in one direction in response to a limit switch indicating that the lifting arm 6 has reached a target rotational position or the lifting arrangement 8 has reached a target lift position.

The positioning of any limit switches and the adjustment of any limits are set during installation of the hoist 2 because they are dependent on the size and shape of the carrier vehicle 12 opening, the size and shape boot floor that the disability vehicle 10 is loaded onto, and the size and shape of disability vehicle 10.

A typical operation sequence to load a disability vehicle 10 into the carrier vehicle 12 is as follows.

Firstly, a rear door (not shown) of the carrier vehicle 12 is opened to allow access to the hoist 2. The hoist 2 is then pivoted about the vertical axis of the support member 4 to cause the end of the lifting arm 6 to extend out of the opening of the carrier vehicle 12 in the first lifting position (see Figure 3A). This may be achieved, for example, by the operator pressing an 'out' button on the hand controller, which then rotates the lifting arm 6 in a horizontal plane out of the carrier vehicle 12.

Next, the lifting arrangement 8 lowers the attachment 14 and the disability vehicle 6 is attached to the hoist 2. An operator then actuates the lifting arrangement 8, for example using a hand-held control panel, to lift the disability vehicle 12 from the ground to a height required to load it into the carrier vehicle 10.

To do this, the operator continuously actuates the lifting arrangement 8 until the lifting arrangement 8 reaches the lifting limit and the lifting limiter causes the lifting arrangement 8 stops lifting. This may be achieved, for example, by pressing an 'up' button on the hand controller until lifting stops. The stopping function may be triggered by the disability vehicle 10 being lifted to a height where it operates a limit switch, which in turn disables the motor from lifting any further.

Once the disability vehicle 10 has been lifted from ground to the maximum lifting position, the hoist 2 is pivoted back about the vertical axis of the support arm 4 to move the disability vehicle 10 into the carrier vehicle. This may be achieved, for example, by the operator pressing an In' button on the hand controller, which then rotates the lifting arm 6 in a horizontal plane into the carrier vehicle 12 to the second lifting position (see Figure 3B). Again, the operator holds down the 'in' button until the lifting arm 6 stops rotating.

The operator then lowers the disability vehicle 10 onto the floor of the carrier vehicle 12. The attachment means 14 remains attached to the disability vehicle 10 to simplify unloading (it is often difficult to attach and detach such attachment means in situ) and to provide additional restraint against movement of the disability vehicle 10 during transit.

The same process is performed in reverse in order to unload the disability vehicle 10 from the carrier vehicle 12.

-12 -When the carrier vehicle 12 is used to transport the disability vehicle 10, the lifting arm 6 is often in a position that at least partially blocks the vision of the driver of the carrier vehicle through the rear view window. Whilst the carrier vehicle 12 is used to transport the disability vehicle 10, there is little that can be done to avoid this problem. However, it is desirable that the view is not obstructed during use of the carrier vehicle 12 for purposes other than transport of the disability vehicle 10. Accordingly, responsive to an override condition being met, the position limiter is disabled to allow the hoist 2 to be further rotated into a stowed position (see Figure 3C) within the carrier vehicle 12. A second position limiter, similar to the first position limiter described above but without an override, is provided to prevent rotation of the hoist 2 beyond the stowed position. It has been found that this further rotation is generally sufficient to move the lifting arm out of the rear view of the driver, making driving experience easier and safer.

In one embodiment, the hoist 2 described above is configured so that after the position limiter stops the motor from further rotating the hoist 2, when the user releases and again presses the 'in' button, the motor restarts allowing the lifting arm 6 to retract further into the vehicle towards the stowed position. In due course, the lifting arm 6 will reach a second position limiter, which will further disconnect the power to the electric motor. As above, the second position limiter may include a limit switch, the positioning of which is again performed during installation of the hoist 2.

In an alternative embodiment, a load sensor is provided, which is configured to detect whether a minimum threshold weight is being carried by the lifting arm 6. When more than the threshold weight is being carried (i.e. the disability vehicle 10 is being lifted), the load sensor is triggered and the lifting arm 6, when being retracted into the carrier vehicle 12, will be stopped at the first rotation limiter. However, when less than the threshold weight is being carried (i.e. the disability vehicle 10 is not being lifted) and the lifting arm 6 is being retracted into the carrier vehicle 12, a signal from the load sensor unit will override the rotational position limiter, thus allowing the lifting arm 6 to rotate until it reaches the second rotational limiter in the stowed position.

It will be appreciated that the embodiment described above is a preferred embodiment only of the invention such that various changes could be made thereto which would fall within the scope of the invention as defined by the appended claims.

-13 -For example, an alternative embodiment of the hoist 2 may use Hall Effect sensors, rotating disc sensors, or other similar rotational counting systems to determine when to limit rotation of the lifting arm 6. In this case, the setup procedure may not involve a limit sensor, but instead an arrangement that counts pulses. For example, it may be determined that for the rotational travel in a given system, the range of full in' to 'full out' is 536 pulses. For the override mode (when the disability vehicle 10 is not in use), the hoist 2 may then be allowed to rotate the arm back in for 733 pulses from the 'full out' position to move to the stowed position. In such an implementation, the positions (full out, full in with disability vehicle 10, and full in without disability vehicle 10) may be programmed at installation by the installer, for example by pressing a certain combination of buttons on the handset. In one implementation this could be effected by depressing the 'in' and 'out' buttons simultaneously, which would be detected by the system controller as activating a 'programming' mode.

Figure 4 shows an alternative hoist 102 that may be used in combination with the movement limiters discussed above. The hoist 102 shown in Figure 4 is similar to the hoist 2 shown in Figure 1, and only the differences between the hoists 2, 102 will be discussed. Unchanged components have been labelled using the same reference signs in both figures.

The hoist 102 uses an alternative lifting arrangement 108. In this embodiment, two fixed lifting arms 6a, 6b are each mounted at one end to the support member 4 and at the other end to a motor-driven lifting arrangement 108. Suitable motor-driven lifting arrangements 108 are known.

The details of the lifting arrangement 108 are shown in Figures 5A and 5B.

Figure 5A illustrates the lifting arrangement 108 mounted in a known orientation.

Figure 5B illustrates the lifting arrangement mounted in a new orientation.

The lifting arrangement 108 comprises a spool 20, driven by a motor (not shown). About the spool 20 is wound a lifting line 22, which is of at least sufficient strength to carry the weight of a disability vehicle 10. The line 22 is fixed to the spool 20 at one end and to an attachment hook 24 at the other, although other attachments 14 may be used, such as those discussed above.

The lifting arrangement 108 is enclosed by a housing 26 defining a guide opening 28, through which the line 22 is let out. The guide opening 26 is defined by two guide members 30a, 30b.

-14 -In the past, as illustrated in Figure 5A, the lifting arrangement 108 was mounted to the hoist 102 so that the spool 20 would rotate about a substantially horizontal rotational axis. The guide opening 26 was oriented downward, which is the most natural orientation for lifting a load vertically.

In use, the motor would rotate the spool 20 so as to unwind the line 22. The line would run out of the guide opening 26 and over one of the guide members 30a. The guide member 30a in the past therefore served to centre the loading applied to lifting arrangement 108.

In accordance with an embodiment of the present invention, illustrated in Figure 5B, the lifting arrangement 108 has been rotated so as to move the guide member 30a, over which the line 22 runs, upwards with respect to the spool 20. In particular, the lifting arrangement 108 has been rotated so that the upper surface of the guide member 30a, over which the line 22 runs, is vertically above the level 32 of the lower surface of the spool 20.

As will be apparent, the rotated arrangement allows the attachment hook 24 to be lifted higher than in the prior art arrangement shown in Figure 5A. The arrangement shown in Figure 5B provides two main advantages over the prior art arrangement. The first is that, when the carrier vehicle 12 is used for purposes other than the transport of the disability vehicle 10, having the attachment hook 24 as high as possible minimises obstruction of the rearward view of the driver of the carrier vehicle 12. Secondly, the ability to raise the attachment hook 24 even slightly higher allows either a larger disability vehicle 10 to be moved through the opening of the carrier vehicle 12, or a disability vehicle 10 of a given size to be loaded into a carrier vehicle 12 having a smaller opening.

These two advantages offer enormous benefits to users of disability vehicles and carrier vehicles 12. For example, replacing a carrier vehicle 12 because the opening is slightly too small to fit a user's disability vehicle 10 could cost thousands of pounds. Similarly, downsizing to a smaller disability vehicle 10 may also be expensive and will probably have less range. By way of summary, this arrangement seeks to allow the biggest possible disability vehicle 10 in the smallest carrier vehicle 12 that can carry it.

The following clauses set out features of the disclosure which may or may not presently be claimed, but which may form the basis for future amendment or a divisional application.

-15 - 1 A hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle, the support arm being pivotally moveable from a first rotational position for deploying the disability vehicle onto the ground, through a second rotational position for stowing the disability vehicle within the carrier vehicle, to a third rotational position for stowing the lifting arm within the carrier vehicle, the first, second and third rotational positions being different; and a first rotation limiting means configured to prevent the lifting arm from pivoting beyond the second rotational position, the first rotation limiting means including an override to disable the first rotation limiting means responsive to an override condition being met so that the lifting arm can rotate to the third rotational position.

2. A hoist apparatus according to clause 1, further comprising: a load sensor for sensing a load carried by the lifting arm, wherein the override condition is that the lifting arm is carrying a load that is below a threshold load.

3. A hoist apparatus according to clause 2, wherein the threshold load is less than 75 kg, and more preferably less than 40kg.

4. A hoist apparatus according to clause 1, wherein the override condition is receiving a manual input from a user to override the first rotation limiting means.

5 A hoist apparatus according to clause 4, wherein the lifting arm is rotatable responsive to a user actuating a control, wherein the first rotation limiting means stops further rotation of the lifting arm responsive to the lifting arm reaching the second rotational position, and wherein the manual input is the user releasing the control and re-actuating the control when the lifting arm is in the second rotational position.

6. A hoist apparatus according to any preceding clause, further comprising: a second rotation limiting means configured to prevent the lifting arm from rotating beyond the third rotational position.

7. A hoist apparatus according to any preceding clause, wherein the lifting arm is rotatable by an electric motor and the rotation limiting device prevents the lifting arm from pivoting beyond the second rotational position by stopping supply of electricity to the electric motor.

8. A hoist according to any preceding clause, further comprising a four-bar linkage; and a linear actuator arrangement, wherein the support arm is connected to a first body of the linkage, the first body being adapted to be -16 -connected to a second body of the linkage which, in use, does not rotate with respect to the carrier vehicle; and wherein the linear actuator is arranged to actuate the four bar linkage to rotate the support arm.

9. A hoist apparatus according to clause 8, when dependent on clause 7, wherein the linear actuator comprises the electric motor.

A hoist apparatus according to clause 8 or 9, wherein the first body of the linkage has a V-shape comprising two diverging legs, a first of the legs including the connection to the support arm and the pivotal connection to the second linkage.

11. A hoist apparatus according to any preceding clause, further comprising a lifting arrangement for lifting the disability vehicle.

12. A hoist apparatus according to clause 11, wherein the lifting arrangement comprises: a motor-driven spool about which is wound a lifting line, and the lifting arrangement being mounted to the support arm such that, when the support arm is installed in a carrier vehicle, the rotational axis of the spool is substantially horizontal, wherein the lifting arrangement further comprises a guide member located such that, in use, when the line is unwound from the spool, the line passes from the spool and over the guide member; and wherein the guide member is located such that, in use, a top surface of the guide member is vertically higher than the level of a bottom surface of the spool.

13. A carrier vehicle comprising the hoist apparatus of any preceding clause 14. A carrier vehicle according to clause 13, wherein the lifting arm obstructs the rearward view of a driver of the carrier vehicle less in the third rotational position than in the second rotational position.

15. A hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle; a four-bar linkage; and a linear actuator arrangement, wherein the support arm is connected to a first body of the linkage, the first body being adapted to be connected to a second body of the linkage which, in use, does not rotate with respect to the carrier vehicle; and wherein the linear actuator is arranged to actuate the four bar linkage to rotate the support arm.

16. A hoist apparatus according to clause 15, wherein the first body of the linkage has a V-shape comprising two diverging legs, a first of the legs including the connection to the support arm and the pivotal connection to the second linkage.

-17 - 17. A hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle; and a lifting arrangement for lifting the disability vehicle, the lifting arrangement comprising a motor-driven spool about which is wound a lifting line, and the lifting arrangement being mounted to the support arm such that, when the support arm is installed in a carrier vehicle, the rotational axis of the spool is substantially horizontal, wherein the lifting arrangement further comprises a guide member located such that, in use, when the line is unwound from the spool, the line passes from the spool and over the guide member; and wherein the guide member is located such that, in use, a top surface of the guide member is vertically higher than the level of a bottom surface of the spool.

18. A hoist apparatus according to clause 17, further comprising an attachment for attaching the line to the disability vehicle.

19. A hoisting apparatus according to clause 18, wherein the guide member causes the attachment to be lifted, when the line is fully retracted, to a position higher than if the guide member were not present.

20. A carrier vehicle comprising the hoist apparatus of any of clauses 17 to 19.

Claims (3)

1. -18 -CLAIMS1. A hoist apparatus for lifting a disability vehicle into a carrier vehicle, the hoist apparatus comprising: a support arm for supporting the weight of the disability vehicle; a four-bar linkage; and a linear actuator arrangement, wherein the support arm is configured to be mounted to the carrier vehicle so as to be rotatable about a vertical axis; wherein the support arm is connected to a first body of the linkage, the first body being adapted to be connected to a second body of the linkage which, in use, does not rotate with respect to the carrier vehicle; and wherein the linear actuator is arranged to actuate the four bar linkage to rotate the support arm about the vertical axis.
2. 2. A hoist apparatus according to claim 1, wherein the first body of the linkage has a V-shape comprising two diverging legs, a first of the legs including the connection to the support arm and the pivotal connection to the second linkage.
3. 3. A carrier vehicle comprising the hoist apparatus of any preceding claim.