GB2551309A - System for drawing a wheeled passenger support into a vehicle - Google Patents

Abstract

A system for drawing a wheeled passenger support 16 into a vehicle comprising first 24a and second winches each with a spool 28, a winch cable 30a which can be wound round the spool 28 and coupled to a passenger support 16 and a motor to drive the spool wherein a control system 34 is provided which employs sensors which can monitor rotation of the two winch spools 28 to control the motors to provide an even pull on the passenger support in use. The sensors may measure the number of revolutions or rate of revolution and use magnetic indicators as part of a Hall effect arrangement. A locking arrangement may utilise a ratchet and pawl mechanism and the winches may be pivotally mounted. The device may be used to pull a wheelchair up a ramp and restrain it against further movement.

Description

SYSTEM FOR DRAWING A WHEELED PASSENGER SUPPORT INTO A

MEHIGLE

The present invention relates: to a system for drawing a wheeled passenger support into a vehicle and selectively inserting the passenger support against movement. In particular, hut not exclusively, the present invention relates to a system for drawing a wheeled passenger support such as a wheelchair, wheeled bed or stretcher into a vehicle and selectively restraining the support against movement

It is common practice in modern vehicle design; to modify standard road-going vehicles to include equipment which provides access for a; wheeled passenger support, such as a wheelchair, eta wheeled bed/stretcher, into the vehicle. Typically, the modification process involves installing a lowered floor, and an inclined;ramp along which the passenger support can travel toaeeess theveblcle. The ramp is usually either powered and retractable into the body of the vehicle, or provided as a separate component which can be stored in the vehicle and manually deployed when required.

Manually manoeuvring a passenger support and its occupant along the ramp and into the vehicle can be challenging. Accordingly, a number of different types of powered systems have been developed, tor drawing the passenger support into the vehicle with minimal attendant assistance.

One such System comprises a win# having: a cable whieiis coupled to the passenger support, for drawing the support up the ranip and into the vehicle, and a pair of restraining devices known as ‘electric reefs’. The electric reels are used to restrain the passenger support against movement within the vehicle during transit. Electric reels comprise a reel or spool, a strap fofi the type found in vehicle seatbelt assemblies! wound on to the spool, a; sprung retracting mechanism for the strap, and an eleertiGaily-operated lock. 1'he electric reels are usually positioned at spaced locations within the vehicle, with the Wihch at a central position between the electric feels. Most systems of this type are rear-loading, in Which the passenger support is drawn--in through a rear door of the vehicle. In this situation, the;;;wineh is usually positioned on or sear tie centre-line of the vehicle, with the electric reels disposed laterally either side of the winch, at equidistant sppings.

When it is desired toi draw the passenger support into the vehicle, the winch cable and the electric reel Straps are paid out and coupled tootle passenger support. At this time,: the; electric reel locks are deactivated. The: winch is then activated, drawing the passenger support up theiraiup and into the vehicle interior. During this movement, the retracting; mechanisms of the electric reels automatically reel the straps; back on to their spools, maintaining tension in the straps. When the passenger support has been located at a desired position within the vehicle, the electric reel locks are actuated. This restricts payout of the straps; from the spools, exerting restraining forces on the passenger support, to resist movement during transit. The electric reels are activated/energised to pay out the strap, The eleetie reefs are deactivated/de-energised whilst the winch pulls the wheelchair into the vehicle, so that they will not pay the strap out; This is to make sure that, if the winch fails or the assistant slips, the wheelchair will be securely held. A simplified version of the system described above dispenses with the winch, and includes a pair of modified electric reds. The modified electric reels incorporate a motor, which drives; the spool to reel in the strap. In this wav, the electric reel straps can be used to draw the passenger support, into the vehicle. Following draw-in, the electric reels perform their conventional function of restraining the passenger support against movement during transit. Λ significant problem flat can lx? experienced with simplified systems of this type is that the eleetrie reel spools are driven separately, by their respective motors. This can result in an uneven pull on the passenger support, if the motors; reel in their respective straps it different rates, This causes the passenger support to twist, making it difficult to manoeuvre it into the vehicle, it can also make it difficult to wind the straps back on to the reds, as the straps can hunch or ride up on an end plate of the spool. In extreme situations, the passenger support earn become jammed against internal parts of the vehicle, Even if draw-in can be completed, it is undesirable for the passenger support to; be in a twisted position in the vehicle, as this ean resnli in uneven restraining loads being imparted on the support, putting the passenger at risk of injury in the event of a sudden deceleration of the vehicle.

Similar problems can occur if the: passenger support is positioned slightly off-centre, relative to the electric reels. In parieirlar, a passenger support that is positioned off-centre is effectively further away from one of the electric reels than the other, so that a greater length of strap is paid out from the reel that is further away. As a consequence, when the motors are activated to reel in the straps, an uneven pull is exerted on the passenger support, causing it to twist.

It is amongst the objects of the present invention to obviate or mitigate at least one of the foregoing disadvantages.

According to a first aspect of the pteseht inventiofo® for drawing a Wheeled passenger support into a vehicle and selectively restraining the passenger support against: movement, the system comprising: timl and second winches, each Wmch comprising a spool, a flexible elongate winch element which can be wound on to the spool and which is adapted to be coupled to the passenger support, and a motor for driving the spool to reel in the winch element; and a Control system for controlling operation of the first and second winches; in which the first and second winches afeiiadapted to be mounted within the vehicle and are operable to draw the passenger support into the vehicle, via the flexible elongate winch elements; and in which the control system comprises a first sensor for monitoring:rotation of the first winch spool, a second sensor for monitoring rotation of the second winch spool, and a controller which is arranged so that it can operate the first and second winch motors independently, based on information relating to rotation of the first and second winch spools provided by the first and second sensors; to maintain a substantially even puli on the passenger support during draw-in.

Typically lie vehicle will be of a type which has beep modified ip provide access for the wheeled passenger support into the vehicle, for example by installing a lowered floor, and £tn ihefihed ramp along which the passenger support can travel to access the vehicle.

The ability to operate the first and second winch motors independently, based on information relating to rotation of the first and second winch spools provided by the: first and second sensors, may mitigate at least some of the problems which have been experienced with prior systents discussed above.

Ip particular^: in prior systems: incorporating modified electric-reels, it was found that an uneven pull can be exerted oh the passenger support, in a situation where the motors reeled In the straps at different rates, resulting in twisting of the support. In addition, it was not possible to account for off-centre location of the passenger support. In the system of the present invention,.an uneven pull can he restricted, and potentially avoided, by monitoring rotation of the winch spools and independently operating the winch motors. This may also account for the passenger support being positioned pfTeenire.

Specifically, in the event that one winch motor is found to befotfeing its winch spool at a fester rate than the motor of the pfijer wdnch - a situation which could lead to an uneven pull on the passenger support --- such is detected by the controller, based on the information provided by the first and second sensors. This cap be corrected by appropriate control of the winch motors. For example^ the winch motor which has been rotating i ts spool at a higher speed may be briefly paused.

An off-centre positioning of the passenger support can be detected by the controller, as a greater length of winch clement is paid out from one of the spools during coupling tp the passenger support. This is recognised by the controller because the spool from which the greater length of winchelement is: paid out will be rotated further than the spool of the other winch. This can fee accounted: for by the Controller during: draw-in. by appropriate control of rotation of the winch spools, to avoid twisting of the passenger support.

The first and second sensors may fre arranged to monitor one or more parameter! Which may be selected from the group comprising: a number of revolutions (or part-revolutions as appropriate) performed by the respective winch spools: and a rate of rotation of the respective winch spools. The first and second sensors may be arranged to output data relating to the one Of mom parameter to the controller. The controller may be arranged to process tbedata, to determine any adjustment to a number of revolutions (or part revolutions) to he peiformed by at least one of the winch spools, and/or a rate of rotation of at least one of the winch spools, that is required to maintain the substantiafly even pull.

The controller may comprise a pMCesSdf for processing the data. The controller may be arranged to vary a number of revolutions (or part-revolutions) performed by a selected one qf the: winch spools by stopping rotation of said winch spool whilst allowing the other to continue to rotate. The controller may be arranged to vary a rate of rotation of a selected one of the winch spools by stopping rotation of said winch spoof or by restricting the power supplied to said winch. The winch may be electrically powered Jh which case power restriction may involve restrictingdleettieal power supply to the winch.

The first and second sensors may be arranged to detect at least one indicator element associated with the respective spool. Detection of the at least one indicator element may provide an indication of anunrfeer of revolutions (or part^foVolutions as appropriate) performed by the respective winch spools, and/or a rate of rotation of the respective winch spools: The at least one indicator element may be provided: integrally With the spool. The at least one indicator element may be provided as a separate component, and may be coupled to the spool.

The winch spools may each comprise end plates, and an end plate of each winch spool may comprise the at least one indicator element. The end plate may be circular, and the at least one indicator clement may be povided at of substantially adjacent to a radial edge of the end plate. There may be a plurality ofindicator elements, which may be arranged at spaced locations around a eireumiercnce of the end plate. The indicator elements May tale the form of casteliations or teeth.

The first and second singers may be Hail effect sensors. T he at least indicator element may be a magnetic indicator element. Ihe Hall effect sensors may be arranged to output a voltage signal in responseto defection Of the magnetic indicator elements. The Hall effect SeiSors may comprise circuitry which is arranged so that the sensors act as Hall switches» arranged to output a digital signal on detection of the at least one magnetic iniieator element. The Hall switches:«lay be arranged to output a digital On’ signal on detection:of the presence oftie at least one magnetic: indicator element. The Hall switches may be arranged to output a digital ‘off signal Wien the presence of the at leasf one magnetic,: indicator element is not detected:.

Where the first and second sensors are Mali effect sensors, and the at least one indicator element is a magnetic indicator element, the sensors may comprise a slotfeffehahttei and may be arranged relative to ffaei spool end plates so that the at least one magnetic indicator element passes through: said s|n& TheHall sensors may be arranged to output» signal on detection of the magnetic indicator element within said slot.

Where the winch spools comprise end plates, the end plates may be magnetic and may define the at least one magnetic indicator element. The end plates may be non-magnetic, and the at least one magnetic indicator element may be couples! to file end plate.

The System ihay COtipfise a piyoting mounting for the first winch. The system may comprise a pivoting mounting for the second winch. The winch or winches may be pivotal ly mountable to the vehicle via the pivoting mounting. The pivoting mounting may permit pivoting of the winch about an axis which is substantially vertical and/or which is substantially perpendicular (in use) to a floor of the vehicle; The pivoting mounting may facilitate reeling-in (if the flexible elongate winch elements in a situation where the passenger support is positioned off-centre relative to the winches, by allowing pivoting of the winch or winches; about Said axis/axes. The first and/or second winch may comprise a mounting member for the winch spool, which may be a mounting frame,: the spool being rotatably mounted to the mounting member, the pivoting mourning being coupled to the mounting member so that the;mon«ting member can pivot relative to the vehicle. TOb system may be arranged to selectively restrain theipassenger support against movement relative to the vehicle.

The system:; in particular the; first and second winches, may comprise locking arrangements for selectively locking or securing the winch spools against rotation. The locking arrangements may prevent pay-out of the flexible elongate winch elements from the spools and so restrain the: passenger support, 'the locking arrangements may prevent pay-in or draw-in of the flexible elongate winch elements on to the spools.

Tie locking arrangements may coifipfse at least one locking element for locking the winch spools. T he at least one locking element may have a fail-safe stale, in which it is urged: towards a locked position. The locking element may be electrically actuated, and may bp solenoid actuated.

TfeeToeking arrangements may be selectively operable or activatable to secure the winch spool against rotation. The Spoking arrangements may be movable between:a release configuration in which rotation of the spool is permitted; and a locking configuration in which rotation of the spool is restricted.

Tie looking arranpments m a ratchet, and at least one pawl wfheh is operable to engage the ratchet and thereby secure the winch against rotation. The at least one pawl may be movable between: a release position in which the pawl is disengaged from the; ratchet, permitting rotation of the spool; and a locking position in which the at least one pawl is engaged with the; ratchet restricting: rotation of the spool. In the release configuration ofthe loeiing arrangement, the at least one pawl may be in its release position. In the lock ing configuration of the locking arrangement, the at least one pawl may be in its locking position. The at least one pawl may be biased towards its release position.

The ratchet may be a ratchet rings which may be generally annular. The ratchet may comprise a plurality of ratchet teeth, which may be on a radially inner surface of the ratchet ring. Said pawl may comprise at least one tooth for engaging the ratchet teeth. 'the; locking arrangements may comprise a mounting member for the at least one pawl, whiehmay he a Glinting disc, wheel, plate or ring. The mounting member may be coupled to the msfc and may be mounted on a shaft of the motor. The mounting member: may fee rotatably mounted on the motor shaft. The locking arrangement may he arranged to rotate the mduntntg member with foe motor when the locking arrangement is in the release configuration. The locking arrangement may be arranged so that the mounting member is secured against rotation When the locking arrangement is in the locking: configuration.

The locking arrangement may comprise a looking element for selectively securing the mounting member against rotation in at least one direction, lire at least one direction may be a direction which eoffesponds to paying-out of the flexible elongate winch element on the spool. Rotation in both directions may be restricted, and so also in a direction which corresponds to drawingun or paying-in of the flexible elongate winch element.

The locking element may feemoyable between a release position where it permits rotation of the mounting member, and a locking position where it restricts rotation of the mounting member. The mounfing member may comprise a plurality of locking teeth, and the locking: element may be arranged to engage teeth of the mounting member to restrict rotation of the mounting member. The locking element may be a locking arm or finger, which may carry one or more teeth for engaging teeth of the mounting ring,: The locking element may be pivotally movable between its positions. The locking element may be urged or biased (e.g. under the action of gravity) towards the locking position. The locking element:may be moved towards the release position by an actuator, which may Hi a solenoid operated actuator,

The locking arrangemem may eompriSesan activation element for operating the ratchet assembly. The activation element may fee coupled to the motor, and may be mounted on a shaft of the motor. The activation element may be mounted on the motor shaft so that it rotates with the motor shaft, The activation element may be a bobbin. The activation element may serve for moving the ratche|assembly between the release and locking configurations. T he activation element may serve; for moving the at least one pawi between the release and locking positions. The activation element may comprise a cam Surface which cooperates with a corresponding earn surface on the at least one pawl, for urging the pawl to the locking; position. The activation element may urge the at least one pawl to the locking position only when the pawl mounting Member is re§tmiued:;against mnatioh. The activation element; may be rotatable relative to the pawl mounting; member when the pawl mounting member is restrained against rotation, to bring the activation element into contact with the at least one pawl. This may serve to impart a force on the at least one pawl to urge it to its locking position. Rotation of the activation element in a first rotational direction may move them least one pawl to the locking configuration. Rotation ofthe activation element in a second, opposite rotational direction may move the at least one pawl to the release configuration.

Reference is made in this document to a; wheeled passenger support. The wheeled passenger support may le of any suitable type, including but not limited to: a wheelchair; a wheeled bed; a wheeled stretcher; a mobility vehicle; and a child’s buggy, pram or pushchair.

The system may have a; use both in the; dfawing-in of a passenger support and so loading of the support into the vehicle, and for controlling movement of the passenger support dufpg unloading from the vehicle. During unloading; the wihbhes may be; operable to impart a restraining load on the passenger support, to control movement of the Support Tie flexible; elongate elements may be paid-out from Ife; spools during unloading. The; winches may be operable; to arrest movement of the; passenger support.

The flexible elongate wiiteh elements may be selected from the group comprising: a strap; a tie: a cable; a chain; and a combination of two or more thereof. T he elongate winch elements may be webbings or of a webbing material, in particular a safety belt webbing material.

The system may comprise a remote control, for controlling operation of at least one of the winch and the locking assembly, from a remote location. Tie remote location may be external of the vehicle.

The system may be ait assisted system, which may require an attendant dbassistabt:Tor aiding and/or controlling loading and unloading of the passenger support into and out of the vehicle.

Theswinehes may be electrically operated winches, and the system may comprise limiters which limit driving power of the motors, for example in the event of the passenger support becoming obstructed, particularly during drawing-in to the vehicle. This may serve to restrict injury to a passenger. The limiter may be arranged to limit the current Ihafeanbe drawn by the winch motors,::

The system may comprise aluriher winch and associated sensor, the controller arranged to operate a motor of said winch based on information relating to rotation, of a spool of the wineh, to praintaih the substantially even pull.

According to a second aspect of the present invention, there is provided a vehicle comprising a system for drawing a wheeled passcngerrsuppOrt into the vehicle and selectively restraining the passenger support against movement according to the first: aspect; of the invention.

Further features of the system forming part of the vehicle of the second aspect of the invention may be derived from the text set out above relating to the first aspect of the invention.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: fig, 1 is a perspective view of a vehicle of a type which has been modified to provide access: for a wheeled passenger support;

Fig. 2 is a side view of the vehicle of Fig. 1, incorporating a system for drawing a wheeled passenger suptort into the vehicle and selectively mstraiiiing the passenger support against mbvmneMyrn accordance with an embodiment of the present invention, the vehicle being: shown in partial longitudinal cross-section;

Fig. 3 is a perspective view of the system shown in Fig. 2, taken from above and shown in use, during the drawing-in of a Wheeled passenger support on to a test rig representing part of a vehicle of the type shown in Fig. 1:

Figs. 4, 5, 6 and 7 are enlarged side, front, plan and perspective views, respectively,, of a winch, which can form part of the system shown in Figs. 2 and 3:;

Itgs. 8, 9 and 10 arc enlarged perspective, front and side views, respectively, of an alternative winch, which can form part of the sptem shown in Figs. 2 and 3;

Fig. I f is a cross-sectional side view of the winch shown in Fig. 8, taken about the line A-A in Fig, 9.

Turning firstly to Fig. L there is shown a perspective view oia vehicle, indicated generally by reference numeral 10, of a type which has been modified to provide access for a Wheeled passenger support. The wheeled passengersupport can include, but is not restricted to, a wheelchair, a wheeled bed or stretcher, a mobility vehicle, or a child’s buggy, pram or pushchair. The vehicle 10 has been modified, to include a specially lowered floor portion 12, and includes a hinged ramp 14 which can be folded-up and stored in the vehicle 10 when not required. The ramp can be powered or may be manually deployable. A wheeled passenger support cap pass along the ramp 14 ani on to the lowered floor 12, and so enter and exit the vehicle 1.0.

Fig. 2 is a side view of the vehicle 10, incorporating a system for drawing a wheeled passenger 16 support into the vehicle and selectively restraining the: passenger support against movement, in; accordance with an embodiment of the present invention, the system indicated generally by reference numeral 18. In the illustrated embodimsnfrfhe passenger support 16 takes the torn': of a wheelchair. It will be understood Siat the invention encompasses a vehicle 1G comprising the system 18; Hae vehicle 10 is shown in partial longitudinal cross-section in the drawing, illustrating an internal part of a rear section 20 of the vehicle.

The system 18 is alsoishown in the perspective view of Fig. 3, taken from above and shown in use, during Ifie drawing-in of a wheeled passenger support on to a test rig 22 representing pari of the vehicle 10 shown in Figs. 1 and 2. The test rig 22 comprises a simulated lowered vesicle floor portion 12, and illustrates the system 18 during an Operation to draw-m the wheelchair 16.

The system 18 comprises first and second winches 24a and 24b, which are shown; in more detail in the enlarged side, froht, plan and perspeetive; views; of Figs.4, 5,6 and 7, respectively. The Winches 24a; arid 24b are of ike construeion and operation, and so only a single wineh i| shown inPigs. 4 to 7. Like components of the winches 24a and 24b share; the same references numemls, with the appropriate suffix;

The winchesJ4a, 24b::eaeh comprise a spool (or reel) 28, aJ&Xili&Jlongate wineh element 30 which ean he wound or: to the spool 28 and which is adapted to be coupled to the wheelchair 16, mi $ motor 32 for driving the spool 28 to reel in the winch element 30. The system also comprises a control system, indicated generally by reference humeral 34, for controlling operation Of the first and second wiidhis 24 and 26.

The flexible elongate winch elements 30a, 30b are typically straps, and in particular are straps formed of a webbing material, such as a safety belt webbing material. Materials of this %pe provide a degree of extensibility under load, reducing shock loads on a passenger in the wheelchair 16 in the event of a sudden deceleration of the vehicle 10. The straps 30a, 30b carry suitable fixings (nof shown) for seeuring the straps to the wheelchair; The; fixings may take the form of a seatbelt buckle provided at a position spaced a short distance from an end of the strap, and a latch member on the strap end which can be looped around m frame of the wheelehair and secured to the; buckle.

The first and second winches 24 and 2§ are mounted within the vehicle 10, suitably ai a location abpye the lowered floor 1 % and are operable: to draw the wheelchair 16 into the vehicle 10, via the straps 30, The control system 3d comprises a first sensor 36a for monitoring rotation of the first winch spool 28a, a secon# sensor 36b for monitoring rotation of the second winch spool 28 b, and a controller 40 which is arranged so that it can operate the: first anisseeond winch rhOtofs 32a and 32b independently, based on information relating to rotation of the first and second winch spools 28a and 28b provided by the first and: second sensors 36a and: 3ib.: M this way, it is possible to maintain a: substantially even pill on the wheelchair 16 during draw-in to the vehicle 10, using the system 18.

The ability to operate the first and second winch motors 32a and 32b independently, based on information relating to rotation of the first and second winch spools 28a and 28b provided by the first and second sensors 36a and 36b, may mitigate at least some of the problems which have been experienced with prior systems discussed above.

In particular, in prior systems incorporating modified electric-reels, it was found that an uneven pull can be exerted on a wheelchair, in a situation where the motors reeled in the straps at different rates, resulting in twisting. In addition, it was not possible to account:for off-centre location of a wheelchair. In the system 18 of the present invention, ah uneven pul 1 can be: restricted^ and potentially avoided, by monitoring rotation of the: winch spools 28a and 28b, and independently operating the winch motors 32a and 32b. This may also account for the wheelchair 16 being positioned off-centre.

Specifically, in the event that one of the winch motors: 32a or 32b is found to bedwtating its winch spool 28a or 28b at a fester rate: than the: motor Of the other winch, such is defected by the controller 40, based on the information provided by the first and second sensors 36a and 36b. This can be corrected by appropriate control of the winch motors 32a and 32b. For example, the winch motor which has been rotating its spool at a higher speed may be briefly paused.

An oil-centre positioning of the passenger support may also be detectable by the controller 40, as a greater length of flexible winch element 30a, 30b is paid out from one of He spools 28a, 28b during eotipling to the wheelchair 16. This is recognised by the controller 40 because the spool 28a, 28b Hi which the greater length of winch element 30a, 30b is paid out will be rotated furtherlhan the spool of the other winch during: umeeing flsifi the: spool. This fan be accounted for by the controller 40 during draw-in, by appropriate control of rotation of the winch spools 28a;and 28;b, to avoid iwisting5©##^«#^&i2r 16,

Whilst the system 18 has been described primarily in relation to the drawingun of the wheelchair 16 into the vehicle 10, the system 18 can also serve for controlling movement of the wheelchair 1:6 during unloading from the vehicle 10. Accordingly, the system 18 has a use both in the drawing-in of the wheelchair 16 and so loading; of the; wheelchair into; the vehicle 10, and for controlling movement of the wheelchair 16 during Unloading from the vehicle 10. Ifi particular, the system 18 is operable to control descent of the wheelchair 16 down the ramp 14, and can control operation of the winches 28a, 28b to ensure substantially even passage of the wheelchair 16 without twisting.

The system 18, and: its method of operation, will now be described in more detail.

The first and second sensors 36a and 36b are arranged to monitor one or more parameter, which may be a number of revolutions (or part-revolutions as appropriate) performed by the respective winch spool 28a or 2|b, and/or a rate; of rotation of the respective winch spool. 1 he sensors 36a and 36b are: arranged to;output data relating to the measured parameter(s) to the controller 4Θ. The controller 40 is arranged to process the data, suitably via an appropriate built-in processor (not shown), to determine any adjustment to a number of revolutions (or part; ;revolutions) to be performed by a selected one of the winch spools 28a or 2 8b, and/or a rate o f rotation ope of the wineisspnols, so as to maintain a substantially1 even pull.

The controller 40 can vary a number of revolutions (or part-revolutions) performed by the selected winch spool 28a or 28b by stopping rotation of the selected spool whilst allowing;; the other to continue to rotate. Addidonafly Ur alternatively, the controller can vary a rate of rotation of a selected one of the winch spools 28a or 28b. by stopping rotation of the selected spool, or by restricting the power supplied to the winch 32a, 32b associated with the spoof Xhe winches 32a. 32b will typically be electrically powered, via a suitable battery 4lj powersfesiriction thus involving restricting :®:;Shpply Of electrical power to the appropriate winch.

To facilitate determination of a number of revolutions (or pari-rcvoliiions) performed by the winch spools 28a and 28b, and/or a rate of rotation of the spools, the system 18 comprises at least One indicator element 44a* 44b'associated with each spool 28a, 28b, In the illustrated embodiment, the spools 28a, 28b comprise a plurality of respective indicator elements 44a, 44b. The first and second sensors 36a, 3:6b are arranged to detect the respective indicator elements 44a, 44b, detection of the indicator elements providing ah indication pf a number of revolutions (or part-revolutions as appropriate) performed by the respective winch spool 28a, 28b and/or a rate of rotation of the respective spool.

Specifically, the number of indicator elements 44a, 44b and their positions on the spools 28a, 28b is knowhi Consequently,The number of revolutions or part revolutions: performed by the winch spools 28a, 28b can be; determined by ‘counting’ the number of indicator elements detected:by the sensors 36a, 36b during reeling-in (or indeed paying-out) of the flexible elongate straps 30a, 30b.

In the illustrated embodiment/ the winch spools 28a, 28b comprise respective; hubs 45a, 45b and spaced end plates 46a, 48a and 46b, 48b. The indicator elements 44a and 44h are provided on the end plates 46a and 46b nearest the motors 32a and 32b. As cup: be seen frbtn the drawing, the end plates 46a and 46b are circular, and the indicator elements 44a, 44b are provided a radial edge of the plate. Thoindicaior elements44a, 44b are arranged at spaced locations around a circumference of the end plates 46a, 46b, and optionally take the ifbrm of castellations or teeth, in the illustrated embodiment, the first and second sensors 36a and 36b are Hall effect sensors, and the castellations 44a and 44b are magnetic. This can suitably he achieved by construciingsthe; spool end plates 46a and :46b/of aimagnetic material. Alternatively, the magnetic indicator elements 44a, 44b eati be provided ai Separate components, coupled n> the; end plates 46a and 46b, which will then be nommagnetie. The sensors 36a and 36b ares arranged to oufpuia voltage^ignaito liiecontrolier 40 in response to; detection bfth&i castellations 44a and 44b. Tite sehSdrs 36a and 36| comprise suitable circuitry (not shown) which |s arranged so that the: sensors act as Hal] switches, outputting a digital signal on detection of the castellations 44a. 44b. The switches 36a, 36b output a. digital ‘on’ signal oh detection of the presence of castellations 44a, 44b, and a digital ‘off signal when the presence of castellations is not detected. Accordingly, a number of revolutions (or part-revolutions) performed by the winch spools 28a and 28b, andfor a rate of rotation of the spools, can be determined by counting the number of 'on5 signals (which may be referred to as ‘clicks’) supplied by the switches 36a, 36b to the controller 40. A Si best: shown in Flgi. 5, the Hall switches 36a, 36b comprise slots or channels iOa, 50b whiefesare arranged relative to the spool end plates 46a, 46b so that the castellations 44a, 44b:pass through the slots. The Hall sensors 36a, 36b arc thus arranged to outfota signal on detection of a castellation 44a, 44b within the slot 50a, 50b. 'Hte system 18 also comprises; pivoting mountings fohite first and: second winches 24a, 24% the mountings shown schematically in Fig; f and given the reference numeral 52a, 52% The pivoting mountings 52a, 52b are single point; mountings which serve for pivotally mounting the winches 24a, 24b to the vehicle; 10. The mountings 52a, 52b permit pivoingiOf the winches 24a, 24b about axes 5lai Sib"WhicEare substantially vertical:: and/pr; which are substantially perpendicular (in use) to the floor 12 of the vehicle 10.

Any mounting which facilitates pivoting of the winches 24a, 24b relative to the vehicle 10 may be; employed. Indeed, the skilled person will be aware of alternatives to the mountings disclosed herein. In the illustrated embodiment, the pivoting mountings bia, 52b comprise threaded bolts 54a, 54b; Which pass through bores 56a, 56b in mounting; frames 58a, 58b of the winches 24a, 24bi The bolts 54a, 54b arc secured to the vehicle 10, such as via a corresponding nut, pr |y engagement in a threaded bore (not shown), and effectively clamp the mounting; frames lla, 58b ίο the vehicle. Upper and lower washers 60a, b and iia, b may be provided, to facilitate rotation of the frames 58a, ||b relative; to the vehicle 14 Suitably, tftiw&Shers·· 6f)a, b ancbi2%:::| are of a low friction material, for example a plastics material siteh as PTFE.

When the wheelchair 16 is drawn-in to the vehicle 1% the:flexible elongate straps 30a, 30b are reeled on to their respective spools 28a, 28b. As a result, the angles which the Straps 30% 30b adopt, relative to a centreline 62 of the vehicle 10 (Fig. 3) progressively changes. The pivoting mountings 52a* Mb accommodate such changes by allowing pivoting of the winches 14% 24b about their axes 53a, 53b. Ih addition, the pivoting mountings 52a, 52b can accommodate variations in said angle which occur in a situation where the wheelchair 18 is positioned off-centre relative to the winches 28a, Mb*

The winch motors 32a, 32b are coupled to the spools 28a, life Via worm and wheel gearboxes 60a, 60b, for imparting a drive force on the Spool hubs 45a, 45b. The system 18 is operable to restrain the wheelchair 16 against movement during transit within the vehicle 14 T his can fee achieved by providing locking arrangements (not: shown) for locking the winch spools 2:8% 28b against rotation, to prevent: pay-out of the straps 30a, 30b front the Spools and so restrain the wheelchair 16. The locking arrangements can comprise: at: least one locking element for locking the Winch spools, which may have a fail-safe sfat% In which it is urged towards a locked position. The locking element may be electrically actuated, and may be solenoid:: actuated. In a variation, locking of the winch spools 28% 28b can be achieved fey securing the motors 32a, 32b against rotation, optionally by locking Jlfe gearboxes 6()% 60b against movement.

Turning now to Fig. 8, there is shown a perspective view of an alternative winch, which can form part of the system 18 shown in figs. 2 and 3, the Winch indicated generally by reference numeral 124. It Will be understood that the system 18 would include two such Winches, given the reference numerals 124a and 1241, respectively. The winches 124a/124b are of similar construction: and operation:to the winches 24a/24h:shown in Pigs. 4 to 7 and discussed above. Lile ebmpOnents of the winches 124a/124b with the winches :2'4a/24b share the same reference numerals, incremented by 1 ()0,

The winches 124a/b are also shown in the frhit and side views of Figs, 9 and 10., and in the cross^seetidhal side view of Fig. 11, which is taken about the line A-A in Fig. 9. The winches 124a% differ from the winehosdda/b primarily in terms of locking arrangements 64®% of the winches* best shown in Fig. 11, which serve for selectively locking spools 128a/b of the winches against rotation. Inclusion of the locking arrangements 64a/b has the result that a sensor 136a/b for monitoring rotation of the spool 128a/b is associated with M bid plate !48|/h of the spool 128a b. rather than end plates 146a/b closest to a motor 132a/b of the winch. Accordinglf, in this embodiment the end plate Td8a/b carries indicatornfements 144Λ.

The locking arrangements 64a/b are selectively operable to secure the winch spool 128a/b against rotation. The locking arrangements 64a/b are movable: between a release conftgnratidn* shown in F|g. 11, in which rotation of the spool 128a/b is permitted, and a locking eonfigiratidn in whieh rotation of the spool is restricted.

The loekihg arrangements 64a/b comprise a ratchet assehihly 66a/b, including a ratchet 70a/b. The ratchet 70a/b takes the form of an annular ratchet ring comprising a plurality of ratchet teeth 72a/b.. winch are arranged around a radially inner sur&ee of the fihg, The ratchet assembly also comprises at least one pawl 74a/b. which is operable to engage the ratchet ring 70a/b and thereby secure the spool liia/b against rotation. In the illustrated embodiment, the ratchet assembly 66a/b comprises first pawls 74a/b and second pawls 76A:,:

The: ratchet ring 70a/b is secured to a mounting frame 158a/b of the winch 124a/b. and so secured: against rotation. The pawls 74a/b and 76a/b are movable between release positions (Fig. 1 lj in which they are disengaged from the ratchet ring 7§a/b. permitting rotation: of the spools 128a/b, and a locking position in which they are engaged with the ratchet ring, restricting rptation of the spools. In the release configuration of the locking arrangement 64a/b, the pawls 74a/b and ?6atb are in their mlease positions, whilst in the locking configuration Of the locking arrangement, the pawls are in their locking positions;

Tie pawls 74a/b and 76a/b are pivotally mounted to a mounting member 86a/b of the ratchet assembly 66a/b, via mounting pins i2a/b and:$4i/b, for movement between their release'and locking positions. In the illustrated embodiment* the mounting member 86a/te takes the fonnsof a disssor wheel. The pawls 74a/b and 76a/b comprise respective teeth 78a/b and 8Qa/fe for engaging the ratchet ring 70a/b, in particular ratchet teeth 72a/b of the ratchet ring. The pawls 74a/b and 76a/b are biased towards their release position, and so to: the position of Fig. 11. Suitably, this can be achieved Via torsion springs (not shown), located on the pins 82am and 84ariv

The imounting disc 86a/b is rotatably mounted Oh a shaft |7|7b of the motor 132a/h. The mounting disc 86a/b is arranged so that it can rotate with the motor shaft 87a/b (relative to the ratchet ring ?0a/b) when the locking arrangement 64a/b is in the release configuration, but is secured against rotation relative to the raMtet ring when the locking arrangement:: 6|a7h is in its locking configuration.

The locking arrangement 64afo comprises a separate locking element l8a/b tor selectively securing the mounting disc 86a/b against rotation. The locking element 88a/b takes the fernfefa Socking arm, which is pivotally mophe! % the frame 158a/b so that itscan move between a release position where it permits rotationsof the mounting disc 86a/b, and a locking position (Fig. 11) where it restricts rotation of the mourning disc, the locking element 88a/h must be released from the mounting: disc 86a/b, in order to permit rotation of the disc relative to the ratchet ring 70a/b. in at least one rotational direction (which will be described below).

The mounting disc 86a/b comprises a plurality of locking teeth, shown in phantom outline at 90a/b in the drawing. The locking arm 88a/b is arranged to engage the teeth 90a/b of the mounting disc 8|a/b to restrict rotation of the disc, suitably via one or more tooth, shown in phantom outline at 92a% which engages the teeth of the mounting disc. The locking arm 88a/b is urged or biased towards the locking position, suitably under the: action of gravity. The locking arm 88a/b is moved to the release position under the action of an actuator which, in the illustrated embodiment, takes the form of a solenoid actuator 94a/b. ύ pd 96a/b of the solenoid acfuator 94a/b engages: the locking arm 88a/bto move it fan) its locked position to its release position.

The locking arrangement 64a/b also comprises an activation element 98;a/b for operating the locking arrangement. The activation element ff|i% takes the form of a bobbin, and is mounted on the motor shaft 87a/b for rotation with the shaft. The bobbin 98a/b serves: for moving the locking arrangement 64a/b bet ween its release and locking configurations, and in particular for moving the pawls 74a/b and 7iafb between their release and looking positions. The bobbin 98a/b comprises a pair of protections or lobes 65afo, which define camsiirfoees Wafo that cooperate with corresponding cam surfaces 69a/b on the pawls 74a/|, aiioasi surfaces 71a/b on the pawls 76a/h, for urging the pawls to: their locking positions.

In tise^ the winch !24a/b is initially in a rest position, in which the ratchet pawls 74a/b and 7b:a/b are disengaged from the ratchet rings 70a/b, and the locking arm 88a#is engaged with the pawl mounting disc 86a/b In this position, the winch spools 128a/b are ‘faihsaife5 locked against rotation in the direction of the arrow7 C {Fig. 11), which would pay-out the flexible winch straps; (not shown) wound on the spools. This resists movement of the wheelchair 16 away ftorn the winch 124a/h.

The shape of the teeth 90a/b on the mounting disc 86a/b, and of tire tooth 92a/b on the locking arm 88a/b does, however,: allow the winch strap to be paid-in, and so the Wheelchair to be drawn closer to the; winch 12%% Specifically, the angle of the teeth 90a/b and 92a/b is such that rotation: of the spool 128a/b in the direction B (to pay in the Strap) acts to lilt the locking arm 88a/b up, so that the mounting disc 86a/b can rotate ardund to a position where the tooth 92a/b engages the next-most tooth 90a/b of the disc. liken it: is desired to pay-out the Witlch strap, it is necessary |p operate the solenoid actuator 94a/b, to move the locking arm 88a/h to its release position, where the tooth 92a/b is disengaged from the teeth :90a/b of the mounting: disc 86a/b. This frees the mounting disc 86a/b for rotation relative to the ratchet ring ?0a/b, under the; action of the bobbin 98a/b contacting the pawls 74a/b and 76a/b, as shown in Fig. 11. This allows the motor shall 87a/b to rotate the spool 128a/h in the direction C, to pay-ont the winch strap.

When the winch strap has been paid-out a desired distance, for example for coupling to the wheelchair 16 Ideated outside the vehicle 10, the winches 124a/b are then operated to rotate the spools 128a/t):in the direction B, drawing the wheelchair 16 into the vehicle lf| lit the event of a power failure to the winches 124a/b at this time, the solenoid actuator ®4h;b would be deactivated. A rotation of the spool 128a/b in ! he direction € would then be prevented. This is because deactivation of the actuatopf4|$b: j^^isilhedoc^ig arm 88a/b, which engages the mourning disc 86a/b, preventing the dise:foom rotating in the direction C. Specifically, when the mounting disc 86a/b is stationary (held by the locking arm 8ia/b|, ahi the spool 128a/b caused to rotate in direction C*the pawls 74a/b and 76a/b are forced to engage: Mo the ratchet 70a/b by the cam faces 69a/b and 71a'b. This presents further rdtatioh oi the spool 128a/b in the direction C. This ensures that the wheelchair 16 eanndt layel back down the ramp 14 in an uncontrolled manner during a power failure. V\ hen the wheelchair 16 has been drawn-into the vehicle 10 and located in a desired position, the lociing arrangements 64a/b are operated to secure the wheelchair against movement away from thwwinehes 124a/b. This is achieved by deactivating the solenoid actuators 94a/b, so that the arms 88a/b engage the mounting disc 86a/b. Rotation of the bobbin 98a/b in the direction C (for example, due to a force imparted on the spools 128a/b by foe Wheelchair 16) causes the bobbin to urge the pawls 74a7b and 7|a/b to their locking: positions, where they engagedhe ratchet ring 70a/b. This is due to contact between the earn surfaces 67a/b on the bobbin 98a/b and the cam surfaces 69a/b and 71 fob on the pawls 74a/h and 76a/b.

If it is desired to pay foe winch straps out following operation of the locking arrangements 64a/b, by rotating the spoofs 128a/b in the direction C, then it is first necessary to rotate the bobbin OSafousmall distance in foe oppositedireetion B, so that the pawls 94a/b and 96a/b release from foe ratchet ring: 7ia/b, under the action of the pawl springs. This frees the mounting disc 8|a/b for rotation relative to the; ratchet ring 70a/b, so that foe spool 128¾ can in turn rotate and pay out foe winch strap.

Various modifications pas be made to the foregoing, without departing from the spirit or scope of the present indention.

For example, the system may comprise a remote control, for controlling operation of at least one of the winch and the locking assembly* from a remote location. The remote location may be external of the vehicle.

The system may bi ah assisted system, which may require art attendant or assistant for aiding and/or controlling loading and unloading of the passenger support into and out of the vehicle.

The winches may be electrically operated winches, and the System may comprise limiters which limit driving power of the motors, for example in the event of the passenger support: becoming ohsfrueted, particularly during drawing-in to the vehicle. This may serve to restrict in jury to a passenger. The limiter Pay be arranged to limit the current that can be drawn bydte winch motors.

The system may comprise a further winch and associated sensor, the controller arranged to operate a motor of said winch based on infonnation relating to rotation of a spool of the winch, toipaintam the substantially even pull.

Claims (15)

1, A system for drawing;» wheeled passenger support into a HMele and seleptAely restraining: the passenger support against movement, the system comprising: first and second winches, eaefe winch comprising a spool, afiexible elongate winch element which can be wound on to the spool and which is adapted to be coupled to the passenger support, and a motor for driving die spool to reel in the winch element; and a control system for controlling operation of the first and second winches; in which the first and second Winches are adapted to he mounted within the vehicle and are operable: to draw the passenger support into the vehicle, viathe fieidblc elongate winch elements; and in which the control system comprises a first sensor for monitoring rotation: of the first winefi spool, a second sensor for monitoring rotation Of fie second winch spool, arid a controller which is arranged so that it can operate the first and second winch motors Independently, based on information relating to rotation of the first and second winch spools provided by the first anti second sensors, to maintain a substantially even pull on the passenger support during draw-in. J* A system as claimed in claim 1, in which the first and second sensors are arranged to monitor one or more parameter selected from the group comprising: a number of revolutions performed by the rPSpetive winch spools; and a rate of rotation of the respective vrinch spools.

3. A system as claimed in claim 2, in which the first and second sensors are arranged to output data relating to the one or more parameter to the controller.

4. A system as claimed in claim 3, in Which the: controller is arranged to process the data, to determine any adjustment to a number of^revolutions to he performed by at least one of the winch spools that is required to maintain the substantially even pul. S* A system as claimed in claim 3 or 4, in which the controller is arranged to process die data, to determine any adjustment to a rate of rotation of at least one of the winch spools that is required to maintain the substantially even pull,

6. A system as claimed in any preceding claim, in which the first aiil second sensors are arranged to detect at least one magnetic indicator element associated with the respective spool.

7. A system AS Claimed in claim 6, in Which the at least one indicator element is provided integrally with the spool.

8. A system assclaimed in claim 9, in which the at least one indicator element is provided as a separate component. fi A system as claimed in any one of claims 6 to 8,, in which the winch spools each comprise end plates, the end plates comprising the at least one indicator element. If. A system as claimed in claim 9, in which there are a plurality of indicator elements arranged at spaced locations around a circumference of the end plate.

11. A system as Claimed in any one of claims 6 to 10, in which the first and second sensors are Hall effect sensors arranged to output a voltage signal in response to detection of the magnetie indicator elements,

12. A system as claimed in any preceding Claim, comprising pivoting mournings for the winches, by Which the winches can. pivot about substantially vertical axes. 13¾ A systemas claimed in any preceding Claim, comprising locking arrangements for selectively locking the winch spools against rotation.

14. A system as churned in claim 13, in which the locking arrangements each comprise a ratchet and at least one pawl which is operable to engage foesratehef and therebysecure the wihch spool against rotation, the at least one pawl being movable betweeni a release position in which the pawl is disengaged from the ratchet, permitting rotation of the spoolf and a Peking position in which the at least one pawl is engaged with die ratchet, restricting rotation of the spool

15, A system as claimed in claim 14, in which the locking arrangements each comprise a mounting member for the at least one pawl, the mounting member being coupled to the motor and rotatable with the motor Wien the Socking arrangement is in its release configuration.

16. A system as claimed in claim 15, in which the locking arrangements each compise a locking element for selectively securing the mounting member against rotation in a; direction which corresponds to paying-out of the flexible elongate winch element on the spool

17. A system as claimed in Claim 16, in which the locking element is movable betwe@t%iiiease 'piiiMliriilliiife it permits rotation of the mounting member, and a locking: position where it restiiets rotation of the mounting member.

18, A system: as claimed in claim 17, in which the locking element is moved towards the release position by a solenoid operated actuator. P. A system as claimed in any one of claims 14 to 18, in which the locking arrangements each comprise an activation element for operating the ratchet assembly, the activation element being mounted on a shaft of the motor so that it rotates with the motor shaft.

20. A system as claimed in claim 19, in which the activation element serves for moving the at: least one pawl between the release aid locking positions. 21. h system as claimed in claim 20, in which the activation element comprises a cam surface which cooperates with a corresponding cam surface on the at least one pawl. for urging the pawl to the locking position.

22. A system as claimed in claim 21, in which the activation element urges the at least one pawl to the locking position only when the pawl mounting member is restrained against rotation. ||; A system as claimed in claim 21 or 22, in which: rotation of the activation element in a first: rotational direction moves the at least one pawl to the locking configuration, and fetation of the activation element in a second opposite rotational direction moves the at least one pawl to the release configuration. 2¾ A vehicle comprising a system for drawing a wheeled passenger support into the vehicle and selectively restraining the passenger support against movement according to any one of the preceding claims.