GB2604430A

GB2604430A - Tie down arrangement

Info

Publication number: GB2604430A
Application number: GB2118226.6A
Authority: GB
Inventors: Phillips Martin; Evans Andrew; Saunders Stephen
Original assignee: Safety Belt Solutions Ltd
Current assignee: Safety Belt Solutions Ltd
Priority date: 2020-12-18
Filing date: 2021-12-16
Publication date: 2022-09-07
Also published as: GB202020172D0

Abstract

Tie down arrangement for restraining a mobility vehicle, e.g. wheelchair, relative to a mounting surface e.g. in a vehicle, comprises: frame 24 mountable to the surface; spool 16 rotatably mounted relative to the frame 24 for paying out and retracting webbing 14 carried by the spool 16; locking arrangement 30 moveable between unlocked and locked configurations; and webbing clamp 40, 42 for clamping the webbing 14. The clamping and locking may prevent unintentional webbing pay-out. The clamp may have two parts 40, 42 moveable with respect to each other. One clamping part 40 may include projections to engage or pass through the webbing 14. One clamping part 40 may move linearly relative to the other part 42. The clamping parts 40, 42 may be padded. An actuator may simultaneously operate the locking arrangement 30 and clamp 40, 42. There may be two spools 16 mounted to the same frame and axially spaced apart.

Description

Tie Down Arrangement The present invention relates to a tic down arrangement suitable for restricting movement for example of a mobility vehicle when being carried in a vehicle.

Mobility vehicles are generally utilised for transportation of a passenger over relatively short distances, and it is often necessary to transport the mobility vehicle itself between locations. Such mobility vehicles can be heavy and occupy a large volume and are thus difficult to transport. Vehicles are therefore either adapted or designed to transport mobility vehicles, often through the provision of a retractable ramp allowing access through a tailgate boot lid that enables the mobility vehicle to enter into the vehicle without disassembly or a passenger having to disembark the mobility vehicle. The passenger can then remain in the mobility vehicle inside the vehicle and therefore be transported over longer distances as required. A motorised retractor arrangement comprising a winch may be provided having a distal end for securing to the mobility vehicle and drawing the mobility vehicle up the ramp and into the vehicle. Alternatively, the mobility vehicle may enter the vehicle via its own power source.

A typical arrangement is presented in Figure la and b where in Figure la a mobility vehicle 2 with an occupant 4 seated thereon is drawn onto a vehicle 6 to be safely transported where the mobility vehicle 2 is drawn up a ramp 8 through the action of a forward tie down 10 comprising a retractor arrangement 12 drawing webbing 14 onto a spool. The mobility vehicle is then further secured by rearward tic downs 15 as shown in Figure lb, and the retractor arrangement 12 is then tensioned to restrict forward and rearward movement of the mobility vehicle. A further occupant belt (not shown) is then secured across the body of the occupant providing further restriction on movement.

A problem exists as the mobility vehicle must be safely tied down inside the vehicle in a manner that ensures the mobility vehicle will not move uncontrollably in the event of a sudden acceleration or deceleration of the vehicle. This is achieved through the provision of one or more tie downs. A tie down is an arrangement that enables securing of an object such as a mobility vehicle to a structure such as the bed of a vehicle. The bed of the vehicle may comprise mounting points specifically designed for this purpose. When securing a mobility vehicle, multiple tie downs are typically provided and having securing formations for securing to the mobility vehicle at the forward corners and rearward corners thereby ensuring secure fixing. The rearward tie downs 15 are typically of a fixed length and connect to rearward corners of the mobility vehicle. A pair of forward tie downs are generally provided typically each comprising a spool carrying webbing that has a distal end for connection to forward corners of the mobility vehicle. The forward tie downs may also comprise retractor arrangements for retraction of the webbing onto the spool to ensure tension the webbing. The motorised winch ensures enough tension in the webbing of each tie down such that the mobility vehicle is sufficiently restrained by the four fixings. A locking arrangement is provided for locking the spool of the forward tie downs to prevent unintentional release of webbing from the spool. The locking arrangement may be remotely operated and may be deployed once sufficient tension in the winch cable is achieved. The mobility vehicle is then provided in a secured configuration.

Under conditions of sudden deceleration as a result of sudden vehicle braking the momentum of the mobility vehicle is forwardly and the rearward tie downs resist. this continued forward movement. As the rearward tie downs are in tension before deceleration commences, there is little unwanted forward movement of the mobility vehicle relative to the vehicle. In addition, the passenger restraints safely hold the passenger in the mobility vehicle. When the deceleration stops, which again is likely to be suddenly, the forward restraints act to prevent significant rearward movement of the mobility vehicle. Due to the forces involved however resulting from the combined weight of the mobility vehicle and the passenger, there is some movement of the mobility vehicle and passenger, which in current systems can be significant.

The applicant has realised that a significant disadvantage of such a system is that the rearward motion of the mobility vehicle and the passenger after sudden deceleration is significant. A similar effect occurs if the vehicle is hit from behind and thereby undergoes sudden acceleration. Although the webbing of the forward tic downs is in tension, there is some inherent payout of webbing from the spool in the event of sudden tension on that webbing. This is caused by the webbing compressing onto the spool, meaning that even though the spool does not rotate to pay out webbing, there is effective payout resulting from this webbing compression onto the spool. The effective length of payout can be 10cm depending on the length of webbing wound around the spool, where it will be apparent that a greater amount of webbing wound onto the spool results in a greater effective payout. This effect is demonstrated in Figure 2a which shows a known forward tie down 10 in a pre-crash configuration which incorporates a retractor arrangement (not shown) for retracting webbing 14 onto a spool 16. The webbing extends to a distal end 18 where it is secured to a mobility vehicle (not shown). Following a crash where there is sudden tension applied to the webbing 14 the webbing 14 is pulled tightly onto the spool 1() 16 as shown in Figure 2b. Under these conditions, the distal end 18 of the webbing 14 has been effectively payed out from the spool 16 due to the compression of the webbing 14 onto the spool 16 meaning the distal end 18 is further away from the spool 16 thereby allowing further movement of the mobility vehicle from the forward tie down 10. The difference in movement is shown by arrow 20.

The present invention addresses the abovementioned problem, or at least provides a viable alternative.

According to the present invention there is a tie down arrangement for restraining a 20 mobility vehicle relative to a mounting surface, the tie down arrangement comprising: - a frame arranged to be mounted to the surface; - a spool rotatably mounted relative to the frame, the spool rotatable in a payout direction and a retraction direction; - a webbing for communicating with a mobility vehicle to restrict movement of 25 the mobility vehicle, the webbing carried by the spool and having a proximal end held relative to the spool and extending to a distal end for securing to a mobility vehicle; - a locking arrangement moveable between an unlocked configuration where rotation of the spool in the payout direction is enabled and a locked configuration where rotation of the spool in the payout direction is prevented to restrict payout of the webbing 30 from the spool; and -a webbing clamp for clamping the webbing intermediate the proximal and distal ends of die webbing and being configurable between a clamped configuration and an unclamped configuration.

According to an alternative definition of the present invention there is a tie down arrangement for restraining a mobility vehicle relative to a mounting surface, die tie down arrangement comprising a frame arranged to be mounted to the surface, a spool rotatably mounted relative to the frame, the spool rotatable in a payout direction and a retraction direction, and a webbing for communicating with a mobility vehicle to restrict movement of the mobility vehicle, the webbing carried by the spool and having a proximal end held relative to the spool and extending to a distal end for securing to a mobility vehicle; the tic down arrangement further comprising a webbing clamp for clamping the webbing intermediate the proximal and distal ends of the webbing and being configurable between a clamped configuration and an undamped configuration.

An advantage of the present invention is that the effect of payout of webbing (even though the spool is locked as the mobility vehicle moves rearwardly in the vehicle during either a rear impact or after sudden deceleration) is mitigated. The security of the tie down arrangement is twofold as the locking arrangement ensures the spool will not rotate and the webbing clamp prevents any payout occurring resulting from compression of the webbing onto the spool as this effect is mitigated. Accordingly, the tiedown arrangement provides an extremely safe tiedown arrangement.

The effect of the webbing clamp on the webbing is to prevent or at least significantly 25 restrict movement of die distal end of the webbing in the clamped configuration.

A portion of the webbing intermediate the webbing clamp and the distal end can beneficially only extend to the extent that the webbing deforms when in the clamped configuration.

It will be appreciated that the webbing clamp acts to clamp the webbing directly. Thus, the webbing is beneficially locked by the webbing clamp and is secured to the mobility vehicle at a distal end.

hi the undamped configuration the webbing clamp beneficially does not materially affect payout of the webbing from the spool.

The webbing clamp is beneficially mounted to the frame.

The distal end of the webbing preferably comprises a formation for connecting to a mobility vehicle. The formation may comprise a fixing arrangement (such as for example a karabiner). The formation may alternatively comprise for example a loop for cooperating with a suitable formation on the mobility vehicle.

The webbing clamp is preferably arranged to clamp the webbing at a location intermediate the distal end of the webbing and a location where the webbing leaves the spool. The webbing clamp is preferably secured to the frame. The webbing clamp preferably comprises first and second clamping elements for clamping the webbing therebetween. The first clamping element preferably comprises an engagement formation for engaging with the webbing. The engagement formation preferably comprises a plurality of projections for engaging with the webbing. The first clamping element preferably comprises a pad having the plurality of engagement formations projecting from the pad.

The plurality of projections and webbing cooperate such that. the plurality of projections extend through the webbing in the clamped configuration. This provide significant benefits over simply 'squashing' the webbing between opposing clamping elements which results in the need to provide massive clamping force to ensure slipping is prevented. The webbing preferably comprises a plurality of first strands aligned in a first direction and a plurality of second strands aligned in a second direction generally perpendicular to the first direction, where the first and second plurality of strands are interwoven.

The first clamping element preferably comprises a pad defining a webbing contact surface having the plurality of engagement formations projecting from the webbing contact surface. The second clamping element preferably comprises a second pad defining a second webbing contact surface, wherein the first and second webbing contact surfaces are substantially parallel to one another.

The first and second clamping elements are preferably moveable relative to one another for clamping the webbing therebetween. It will be appreciated that for simplicity only one of the clamping elements is moveable relative to the other clamping element that remains stationary. At least one of the first and second clamping elements preferably moves linearly relative to the other of the first and second clamping elements. This is beneficial as the webbing is clamped better than for example if one of the clamping elements rotates onto the webbing to clamp the webbing between the first and second clamping elements.

The tic down arrangement preferably further comprises a motor for driving rotation of the spool. It will however be appreciated that a spring biases the spool to retract the webbing meaning that the mobility vehicle is pushed into position in the carrying vehicle and the spring automatically retracts the spool thereby taking in excess webbing onto the spool.

The tie down arrangement may comprise a locking arrangement moveable between an unlocked configuration where rotation of the spool in the payout direction is enabled and a locked configuration where rotation of the spool in the payout direction is prevented to restrict payout of the webbing from the spool.

An actuator arrangement is preferably provided for causing movement of the locking arrangement between, and preferably from, the locked and unlocked configuration. Whilst it is possible to prevent retraction of webbing from the spool using the motor, for increased tension in the webbing and prevention of unintentional webbing payout a locking arrangement is preferably provided. The actuator arrangement may comprise a locking pawl for engaging with teeth of the spool and a linear actuator such as a solenoid.

The actuator arrangement is preferably further arranged to switch the webbing clamp between the clamped and undamped configurations.

The actuator arrangement preferably comprises a user operable input for effecting 5 switching between a locked and an unlocked configuration.

The tie down arrangement preferably further comprises a second spool rotatably mounted relative to the frame, rotatable in a payout direction and a retraction direction, and a second webbing for communicating with the mobility vehicle to restrict movement of the mobility vehicle, the second webbing carried by the second spool and having a proximal end held relative to the second spool and extending to a distal end; a second locking arrangement moveable between an unlocked configuration where rotation of the second spool in the payout direction is enabled and a locked configuration where rotation of the second spool in the payout direction is prevented to restrict payout of the second webbing from the second spool, the tic down arrangement further comprising a second webbing clamp configurable between a clamped configuration to further restrict payout of second webbing from the second spool when the second spool is in the locked configuration and an undamped configuration whereby payout from the second spool in the unlocked configuration is enabled.

The first and second spool are preferably spaced apart. across the frame. The first and second spool are preferably axially spaced.

Illustrative embodiments of the present invention will now be described by way of 25 example with reference to the accompanying figures where: Figures la and b are schematic side views of a mobility vehicle in a loading position and a transport position with respect to a vehicle.

Figures 2a and I) are schematic side views demonstrating the problem associated with prior art tie down arrangements before and after a crash situation.

Figure 3a is a schematic perspective view of a tie down arrangement according to an illustrative embodiment of the present invention including a housing, and Figure 3b is a schematic perspective view of the same tie down arrangement with the housing removed.

Figure 4a is a schematic cross-sectional side view of a tie down arrangement, Figure 4b a perspective representation, Figure 4c a side view showing the actuator arrangement for the webbing clamp, and 4c1 an enlarged side view showing the webbing clamp in more detail all according to an illustrative embodiment of the present invention. Figure 4e is a schematic representation of how the webbing clamp interacts with the webbing according to an illustrative embodiment of the present invention.

Figure 5 is a schematic representation of a tie down arrangement according to an illustrative embodiment before and after a crash situation.

Referring to Figures 3a and b there is an illustrative perspective representation of a tic down arrangement according to an illustrative embodiment. The tie down arrangement 10 is utilised as a forward tie down arrangement in order to address the problem as described with respect to Figure 2 of compression of the webbing 14 on the spool 16. The tie down arrangement 10 comprises a frame in the form of a housing 24 to which is mounted one or more spools 16 each carrying webbing 14. In the illustrative embodiment the tie down arrangement 10 comprises two individual axially spaced spools 16 for securing a mobility vehicle at two separate locations. It will be appreciated however that independent housings 24 each carrying a single spool 16 and webbing 14 may be provided for individual positioning in a vehicle. The benefit of combining two spools into a single housing 24 is that a single motor 22 may be utilised to drive rotation of each respective spool 16. The motor may therefore be disposed between the two spaced apart spools 16. The webbing 14 is drawn from each spool 16 and extends outwardly such that the webbing 14 from a first spool 16 is generally parallel to the other webbing 14 from the second spool 16.

Figure 3b is a schematic perspective view of the same tic down arrangement 10 as shown in Figure 3a with the housing 24 removed. Wound onto the spools 16 is the webbing 14 fixed at one end to the spool 16 and releasable from the spool 16 to a distal end 18, where at the distal end there is a connector 26 configured to enable releasable connection to a mobility vehicle 2. Adjacent to the location at which the webbing 14 leaves the spool 16 there is a webbing clamp 22 configurable between a clamped and an undamped configuration. The webbing clamp 22 acts to clamp the webbing 14 at a location between the distal end 18 of the webbing 14 and the point at which the webbing 14 leaves the spool 16, where this location is as close to the point at which the webbing 14 leaves the spool 16 as practicable.

Referring to Figure 4a, a tie clown arrangement 10 is presented in side view and comprises the housing 24 for securing to the load bed of the carrying vehicle. Shown is the spool 16 and webbing 14 arranged to be retractable from and onto the spool 16 extending to the distal end 18. A locking arrangement 30 is provided in the form of a locking pawl 31 which is biased to a locked configuration as shown in Figure 4a and an actuator 32 as best shown in Figure 4b. The locking pawl 31 can be biased to the locked configuration under the action of gravity for example. As shown in more detail in Figure 4b, the locking pawl 31 can be actuated by means of actuator 32 such as a solenoid which acts to force the locking pawl 31 to disengage with corresponding teeth 36 of the spool 16 thereby allowing payout of the webbing 14 from the spool in order to payout webbing for connection to a mobility vehicle 2. It will be appreciated that the locking arrangement 30 is always biased to the locked configuration unless payout of the webbing 14 is explicitly required. A controller (not shown) is provided for operation of the actuator 32, the motor 26 and the actuator arrangement 50 for the webbing clamp 22.

The webbing clamp 22 as shown most clearly in Figure 4a and 4d comprises first and second clamping elements 40, 42 preferably in the form of first and second pads where the first clamping element 40 is moveable relative to die second clamping element 42 for clamping the webbing 14 therebetween. The first clamping element 40 comprises an first webbing contact surface having multiple protrusions 44 as best shown in Figure 4c1 and 4e extending therefrom. The webbing 14 is thereby clamped between the first and second clamping elements 40,42 through the effect of the protrusions extending between the gaps between adjacent strands of the webbing. The protrusions therefore effectively displace adjacent strands and project through the webbing meaning that the webbing is very effectively clamped. This is clearly represented in Figure 4e where the individual strands oldie webbing are visibly push apart and the protrusions 44 can be seen to eb extended between adjacent strands. The protrusions then abut against the second webbing contact surface of the second pad which forms part of the second clamping element 42 meaning that the webbing has no chance of slipping when tension is applied to the webbing in a crash situation. It will be appreciated that in the illustrative embodiment the first clamping element 40 is moveable whilst the second clamping element 42 remains stationary and is moveable via actuator arrangement 50 most. clearly shown in Figure 4c.

The actuator arrangement 50 is operable under operation of the controller (not shown). In this embodiment, the actuator arrangement 50 comprises a linear actuator 52 which acts upon a linking cable 54 in the direction indicated by arrow 56 to force the first clamping element 40 into engagement with the webbing 14. The first clamping element 40 is biased to the undamped configuration.

A mobility vehicle can be safely loaded and unloaded utilising the tie down arrangement and subsequently secured in position in a carrying vehicle. Under loading conditions, the connectors 26 in the form of hooks are withdrawn as the motor unwinds the webbing 14 as the locking pawl 31 is withdrawn from engagement from the teeth 36 of the spool 16. The motor is halted at the appropriate extension and the connectors 26 are attached to the mobility vehicle 2. The motor is then activated, the locking pawl re-engages with the teeth 36 and the webbing 14 drawn back onto the spool(s) 16 thereby dragging the mobility vehicle 2 into the transportation vehicle. Rear tie down(s) 15 are then attached to the rearward end of the vehicle 2 and the tie down arrangement 10 is re-engaged to tension the vehicle between the forward 10 and rearward 15 tie down arrangements. Once enough tension is applied to the webbing 14 through actuation of the motor. the spool 16 is held in place with the locking pawl 31 engaging a tooth 36. The controller then deploys the actuator arrangement 50 and thus effects switching of the webbing clamp from the undamped to the clamped configuration whereby clamping the webbing 14. Accordingly, once in this secured configuration both the webbing clamp 22 and the locking arrangement 30 are deployed meaning that compression of the webbing 14 onto the spool 16 is prevented by the webbing clamp 22 and deployment of webbing from the spool 16 itself is prevented by die locking arrangement 30 being in the locked configuration.

Referring to Figure 5, there is a schematic representation of a forward tie down 10 and webbing clamp 22 according to an illustrative embodiment of the present invention in an unlocked configuration (Figure 5a) whereby webbing 14 is unimpeded by the webbing clamp 22 either leaving or being wound onto the spool and a clamped configuration (Figure 5b) whereby webbing compression onto the spool 16 as shown in Figure 2b is prevented. I()

hi the event of a crash where there is sudden tension applied to the webbing 14 the webbing 14 is pulled tightly against the opposing first and second clamping elements 40,42 of the webbing clamp 22 as shown in Figure 5b. Under these conditions, the distal end 18 of the webbing 14 has extended to a nominal degree indicated by arrow 20 due to the deformation in the webbing itself between the distal end 18 and the webbing clamp 22 however it will be appreciated that this displacement is minimal. Importantly, there is no compression of the webbing 14 onto the spool 16 in such a scenario. As such, rearward movement of the mobility vehicle 2 in a crash situation is significantly restricted.

Aspects of the present invention have been described by way of example only and it will be appreciated by the skilled addressee that modifications and variations may be made without departing from the scope of protection afforded by the appended claims.

Claims

Claims 1. 2. 3. 4. 5. 6.A tie down arrangement for restraining a mobility vehicle relative to a mounting surface, the tie down arrangement comprising: - a frame arranged to be mounted to the surface; -a spool rotatably mounted relative to the frame, the spool rotatable in a payout direction and a retraction direction; -a webbing for communicating with a mobility vehicle to restrict movement of the mobility vehicle, the webbing carried by the spool and having a proximal end held relative to the spool and extending to a distal end for securing to a mobility vehicle; - a locking arrangement moveable between an unlocked configuration where rotation of the spool in the payout direction is enabled and a locked configuration where rotation of the spool in the payout direction is prevented to restrict payout of the webbing from the spool; - a webbing clamp for clamping the webbing intermediate the proximal and distal ends of the webbing and being configurable between a clamped configuration and an undamped configuration.
A tie down arrangement according to any preceding claim wherein the distal end of the webbing comprises a formation for connecting to a mobility vehicle.
A tie down arrangement according to any preceding claim wherein the webbing clamp is arranged to clamp the webbing at a location intermediate the distal end of the webbing and a location where the webbing leaves the spool.
A tie down arrangement according to any preceding claim wherein the webbing clamp is secured to the frame.
A tie down arrangement according to any preceding claim wherein the webbing clamp comprises first and second clamping elements moveable relative to one another for clamping the webbing therebetween.
A tie down arrangement according to claim 5 wherein the firs( clamping element comprises a plurality of projections for engaging with the webbing.
7. A tie down arrangement according to claim 6 wherein the plurality of projections and webbing cooperate such that the plurality of projections extend through the webbing in the clamped configuration.
8. A tie down arrangement according to any of claims 5-7 wherein at least one of the first and second clamping elements moves linearly relative to the other of the first and second clamping elements.
9. A tie down arrangement according to claim 8 wherein the firs( clamping element comprises a pad defining a webbing contact surface having the plurality of engagement formations projecting from the webbing contact surface.
10. A tie down arrangement according to claim 9 wherein the second clamping element comprises a second pad defining a second webbing contact surface, wherein the first and second webbing contact surfaces are substantially parallel to one another.
11. A tie down arrangement according to any preceding claim further comprising an actuator arrangement for causing movement of the locking arrangement between the locked and unlocked configuration
12. A tie down arrangement according to claim 11 where the actuator arrangement is further arranged for switching the webbing clamp between the clamped and undamped configuration.
13. A tie down arrangement according to claim 12 wherein the actuator arrangement comprises a user operable input for effecting operation of the actuator arrangement.
14 A tie down arrangement according to claim 13 wherein the actuator arrangement is arranged to simultaneously cause movement of the locking arrangement between the locked and the unlocked configuration and also switching of the webbing clamp between the clamped and unclamped configuration.
15. A tie down arrangement according to any preceding claim further comprising a second spool rotatably mounted relative to the frame, the second spool rotatable in a payout direction and a retraction direction, and a second webbing for communicating with the mobility vehicle to restrict movement of the mobility vehicle, the second webbing carried by the second spool and having a proximal end held relative to the second spool and extending to a second distal end for securing to a mobility vehicle; the second tie down arrangement further comprising a second webbing clamp for clamping the second webbing intermediate the proximal and distal ends of the second webbing and being configurable between a clamped configuration and an undamped configuration.
16. A tie down arrangement according to claim 13 wherein the first and second spool are spaced apart across the frame.
17. A tie down arrangement according to claim 14 wherein the first and second spool are axially spaced.