GB2446286A

GB2446286A - Tongue and buckle arrangement for restraining a wheelchair

Info

Publication number: GB2446286A
Application number: GB0801681A
Authority: GB
Inventors: Stephen Johnston
Original assignee: CN Unwin Ltd
Current assignee: Braunability UK Ltd
Priority date: 2007-01-30
Filing date: 2008-01-30
Publication date: 2008-08-06
Anticipated expiration: 2028-01-30
Also published as: GB2446286B; GB0801681D0; GB0701726D0

Abstract

A wheelchair restraint strap 100 is disclosed. The strap includes a vehicle floor or chassis fixing 40 at one end and a loop 110 at the other end. The loop 110 includes a releasable fastener 10 which can close and secure the loop 110 around a wheelchair frame or the like in use. The strap may include a length adjuster 50. The fastener 10 has generally two parts: a tongue 20 and a buckle 30, which snap fit together their allowing relative rotation, preferably in three degrees of rotational freedom, so as to mitigate the risk of the two parts separating when the fastener is shock loaded. The buckle can be used with different straps or without the strap.

Description

Tongue and buckle arrangement for restraining a wheelchair The present

invention relates to the restraint of a wheelchair or the like, e.g. during transit of the wheel chair.

Many types of commercially available straps are commonly used to secure wheelchairs when the chairs are transported in a vehicle.

For example the applicant produces a commercially available adjustable length wheelchair restraint strap, one end of which attaches to a rail, in turn attached to the chassis of a vehicle, and the other end of which includes a loop or hook for attaching to a wheelchair frame. The loop includes a buckle and * *I tongue similar to that used conventionally in vehicle seat belts. The tongue has a **** square aperture and snap- fits into the buckle. The buckle has a sprung locking piece which fits within the aperture preventing its withdrawal. The loop can be *** attached to a wheelchair frame by enclosing the frame in the loop and fastening **** * the buckle and tongue together, adjacent the frame. However, tests have shown that, if the buckle and tongue impact against a wheelchair frame in the wrong orientation, then there is a possibility that the tongue will come adrift from the buckle, and thus the wheelchair may come loose during an accident.

Additionally the known tongue and buckle, when brought together, do not permit their relative movement. Thus, when restraining certain wheelchairs there will often be twisting of the strap. Twisted straps distribute their load to a smaller area of wheelchair frame when they are wrapped around the frame which is undesirable. Also a twisted strap is more difficult to fit and remove and is able to carry less load.

Embodiments of the invention address at least the problems mentioned above The present invention according to a first aspect, provides a wheelchair restraint strap comprising a flexible strap element, at one end having means for securing the strap to a vehicle, at the other end having a loop of said material for enclosing a frame member of the wheelchair, the loop being closable by a releasable two part fastener in the form of a buckle and tongue pair attached to said material, the strap being characterised in that the tongue has a spherical or part spherical head for being captively held in an aperture in the buckle, and a neck narrower than the head, such that the tongue can move within the aperture with at least one degree of rotational freedom relative to the buckle.

Thus the strap has a loop section which can be fitted to most frames. Any accidental impact of the fastener with the frame will not release the pair because II.. 0 there are no parts that can be slapped out of engagement. There is no need to 1 twist the strap or loop because the parts are relatively rotatable.

According to another aspect the loop mentioned above could be replaced such that one of the parts is held by the frame of the wheelchair and the other part is attached to a strap. In this case the buckle or tongue can be attached to the wheelchair and no loop of material would be required. There will be no twisting of the strap because the parts can rotate relatively.

Preferably, means for adjusting the length of the strap may be provided.

This adjusting means may be provided intermediate the ends.

According to yet another aspect it is possible to hold the buckle or tongue to a vehicle (e.g. directly to a rail secured to the floor of a vehicle), the other part the being held by the wheelchair frame. In this instance no strap is required and the wheelchair can dock securely so that the parts come together.

Preferably the aperture in the buckle is formed by the inner surface of a cylindrical sleeve having also a wall and an outer surface, the wall containing one or more openings and at least one member associated with one or more of the openings, the or each member in use moving radially outwardly to accept the head and radially inwardly to contact the head in the region of its neck to prevent release of the head from the cylindrical sleeve.

Preferably the or each member comprises a ball and the or each opening has an axis which is oblique to the axis of the cylindrical sleeve. More preferably,

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S... . . . . adjacent the inner surface of the cylindrical sleeve, the or each opening is tapered such that the or each opening has a diameter which is less than the diameter of the or each ball to inhibit the ball's movement toward the axis of the

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cylindrical sleeve.

1 Preferably the buckle includes a collar disposed around the outer surface of the cylindrical sleeve, the cylindrical sleeve being positionable along its axis relative to the collar to allow or inhibit said radial movement of the or each member.

Preferably said radially outward movement of the ball(s) is effected by forcing the head into the aperture so that the member(s) force the cylindrical sleeve into a position relative to the collar such that the member(s) can move radially outwardly and capture the head.

Preferably said radially outward movement of the ball(s) is effected also by moving the cylindrical sleeve into the position relative to the collar such that the member(s) can move radially outwardly to release the head. Preferably the cylindrical sleeve is resiliently biased when captured.

Preferably when captured the head is resiliently biased towards the members/balls.

Preferably as a result of the biasing of the head and its capture in the aperture the tongue is restrained from moving in a linear manner relative to the buckle.

Preferably said one at least one degree of is rotational freedom is rotation about a first axis passing through the centre of the spherical or part spherical head.

More preferably, in addition to said rotation, the tongue is permitted to move in a *: further two degrees of rotational freedom about mutually orthogonal axes, each S..

* of which are perpendicular to the first axis.

I... * The invention extends to any novel or inventive combination of features * described herein. To illustrate the invention by way of example only, various embodiments are described below with reference to the drawings, wherein: Figure 1 shows a fastener for use with the invention; Figure 2 shows a strap according to the invention; Figure 3(a) shows one part of the fastener used with the invention: Figures 3 b&c show sections through a second part of the fastener used with the invention; Figures 4(a) to (e) and 5(a) to (e) show the parts shown in figures 3(a),b&c; and Figure 6 shows a modified version of the part shown in figure 3(a).

Figure 1 shows a fastener for use with the invention. The fastener comprises two parts: a tongue 20; and a buckle 30. The tongue 20 is a snap-fit within the buckle 30. Each part of the fastener has an aperture 22, 32, for a restraining belt e.g. a flexible webbing belt to be passed therethrough.

Figure 2 shows a restraining belt 100 having a floor attachment 40, a fastening loop 110 which loops around a wheelchair frame and is secured by the buckle 10 of Figure 1. The restraining belt 100 can be shortened or lengthened by means of an adjuster 50.

Figure 3(a) shows the tongue 20 in more detail. The tongue comprises * ** the belt aperture 22 and a spherical head portion 24 which is adapted for fitting *** within the buckle 30. Also shown is a necked portion 26 which has a smaller diameter than the spherical head 24.

* Figure 3(b) shows a section through the buckle 30, ready to receive the *.s* * spherical head 24 of tongue 20 within an aperture 36 in the buckle 30. Buckle * 1 30 has a cylindrical sleeve 33 which has openings 38 in its wall. These openings house balls 31 such that the balls 31 are housed individually around the axis A of the sleeve 33. The openings 38 extend to a collar 39 which is connected to buckle body 35. Spring 37 forces the sleeve 33 in direction towards the top of the page of the drawing. In use balls 31 are kept in a radially inward position by the force of spring 37. The radially inner portion of the openings 38 narrows so that the balls are prevented from falling into the aperture 36. A further race of balls 41 limits the movement of the sleeve with respect to the body 35.

Figure 3(c) shows a section through the buckle 30 with a cover 34 forced in the direction of arrows B. In this position the sleeve 2 is forced downwardly (as shown in the drawing). This causes the openings 38 in the sleeve and the body 35 to align such that balls 31 can move radially outwardly so as to accept the head 24 of the tongue 20. When the head 24 has moved past the balls 31, the force in the direction of arrow B can be removed so that the cover 34 moves resiliently to a position as shown in Figure 3(b) but with the head 24 held captive within the buckle 30.

It will be apparent to the skilled reader that when the spherical head 24 is held by the balls 31 within the aperture 36 the tongue can rotate about axis A to give a rotational degree of freedom RI as shown in Figure 1. Additionally, it will be apparent that the tongue can pivot to a limited degree in the directions of R2 and R3 as shown in Figure 1 to give two further degrees of rotational freedom which each have rotational axes which are perpendicular to axis A. When * 1 fastened, the tongue is urged against moving in a linear manner because the head abuts a cup 42 (Figure 3b) which is in turn urged against the head 24 by the spring 43 and which also ensures that the head 24 is held firmly against the balls 38. Thus, there are no linear degrees of freedom in the fastening.

Figures 4(a) to (e) show the fastening of the fastener in more detail. As can be seen from Figure 4(a) tongue 20 is aligned with the aperture 36 of the buckle 30. Figure 4(b) shows the entry of the head 24 of the tongue into the aperture 36. Figure 4(c) shows the compression of spring 37 as the sleeve 33 is forced downwardly by the head 24. Figure 4(d) shows the head passing the balls 31. Figure 4(e) shows the balls moving inwardly to surround the head 24 and capture it within the aperture 36. Figure 4(f) shows the sleeve 33 returned to its rest position by spring 37 so that the head 24 of the tongue 20 is captured within the buckle 30. It is noted that the cup 42 is urged against the head 24 by means of spring 43 to prevent the tongue moving linearly within the aperture 36.

Figures 5(a) to (f) show the release of the tongue 20 from the buckle 30.

Figure 5(a) is the same Figure as Figure 4(f). Figure 5(b) shows load being applied to cover portion 34 so that sleeve 33 is moved to a retracted position which allows baIls 31 to move outwardly. Figure 5(c) shows the head 24 being retracted from the aperture 36 whilst the cover 34 is held down. Figure 5(d) * SI shows the retraction of the head 24. Figures 5(e) and (f) show partial and SS*4 complete retraction of the head from the aperture 36 to quickly release the tongue from the buckle 30. I.

* Figure 6 shows a modification 120 of the tongue 20 shown in the previous Figures. In this embodiment the tongue has a head 124 and a neck 126 which operate in the same manner as the head 24 and neck 26 described above.

However, in this embodiment the neck 126 is attached to a clamp device having two halves 121 and 122 which together can be used to secure the tongue 120 to a wheelchair frame by means of restraint bolts 128. The tongue has a squared aperture 130 which is used to clamp around a circular or other shaped wheelchair frame. In this embodiment a restraining strap which has at one end a floor fixing 40 (as shown in Figure 2) can be used and at the other end a buckle 30 is secured. Optionally a length adjuster device 50 can be disposed along the length of such a strap.

In a further embodiment the tongue 120 can be used with a modified buckle 30 attached directly to the floor of a vehicle or the like such that the wheelchair having tongue 120 can dock with the buckle 30. One or more further docking points can be provided and the wheelchair can be pivoted about the first fastening to dock at a second because the first fastening allows rotation.

Specific embodiments of the invention have been described but it will be apparent to the skilled addressee that modifications, variants, and alterations can be made to those embodiments without departing from the invention set out.

In particular, whilst the invention has been applied to a wheelchair it will be understood that the embodiments could be employed to secure other moveable patient supporting means such as hospital beds, and other wheeled patient supports.

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The head 24 is described as having a spherical form, but it will be apparent that a part spherical form, for example a head having its end flattened or having a hemispherical form, will be equally effective.

Claims

Claims 1. A wheelchair restraint strap comprising a flexible strap

element, at one end having means for securing the strap to a vehicle, at the other end having a loop of said material for enclosing a frame member of the wheelchair, the loop being closable by a releasable two part fastener in the form of a buckle and tongue pair attached to said material, the strap being characterised in that the tongue has a spherical or part spherical head for being captively held in an aperture in the buckle, and a neck narrower than the head, such that the tongue can move within the S.. * aperture with at least one degree of rotational freedom relative to the S.....

* * buckle. *1*

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S... S
2. A wheelchair restraint comprising a flexible strap element, at one end it having means for restraining the strap to a vehicle and at the other end having either the buckle or the tongue of a releasable two part fastener pair, the other of the two parts of the fastener being securable to a wheelchair frame, the restraint being charactensed in that the tongue has a spherical or part spherical head for being captively held in an aperture in the buckle, and a neck narrower than the head, such that the tongue can move within the aperture with at least one degree of rotational freedom relative to the buckle.
3. A wheel chair restraint strap or restraint as claimed in claims 1 or 2 wherein, intermediate the ends, means for adjusting the length of the strap is provided.
4. A wheelchair restraint comprising a releasable two part fastener, one part in the form of a buckle and the other part in the form of a tongue, one part being clampable to a wheelchair frame and the other part being securable to the floor of a vehicle, the restraint being charactensed in that the tongue has a spherical or part spherical head for being captively held in an aperture in the buckle, and a neck narrower than the head, S.. * such that the tongue can move within the aperture with at least one *555*5 * degree of rotational freedom relative to the buckle. *5*

S *.* .
5. A wheelchair restraint strap or restraint as claimed in any preceding claim wherein the aperture in the buckle is formed by the inner surface of a cylindrical sleeve having also a wall and an outer surface, the wall containing one or more openings and at least one member associated with one or more of the openings, the or each member in use moving radially outwardly to accept the head and radially inwardly to contact the head in the region of its neck to prevent release of the head from the cylindrical sleeve.
6. A wheelchair restraint strap or restraint as claimed in claim 5 wherein the or each member comprises a ball and the or each opening has an axis which is oblique to the axis of the cylindrical sleeve.
7. A wheelchair restraint strap or restraint as claimed in 6 wherein, adjacent the inner surface of the cylindrical sleeve, the or each opening is tapered such that the or each opening has a diameter which is less than the diameter of the or each ball to inhibit the ball's movement toward the axis of the cylindrical sleeve. I...
8. A wheelchair restraint strap or restraint as claimed in any one of claims 5,6 or 7 wherein the buckle includes a collar disposed around the S..

outer surface of the cylindrical sleeve, the cylindrical sleeve being *5*S S positionable along its axis relative to the collar to allow or inhibit said radial movement of the or each member or ball.
9. A wheelchair restraint strap or restraint as claimed in any one of claims to 8 wherein, said radially outward movement of the member(s)Iball(s) is effected by forcing the head into the aperture so that the member(s)/ball(s) force the cylindrical sleeve into a position relative to the collar such that the member(s)/ball(s) can move radially outwardly and then inwardly capture the head
10. A wheelchair restraint strap or restraint as claimed in 9 wherein, said radially outward movement of the member(s)/ball(s) is effected by moving the cylindrical sleeve into the position relative to the collar such that the member(s)/ball(s) can move radially outwardly to release the head.
11. A wheelchair restraint strap or restraint as claimed in any one of claims 9 or 10 wherein the cylindrical sleeve is resiliently biased when captured.
12. A wheelchair restraint strap or restraint as claimed in claim 11 wherein, when captured the head is resiliently biased towards the member(s)/ball(s). * .
13. A wheelchair restraint strap or restraint as claimed in claim 12 ** * wherein, as a result of the biasing of the head and its capture in the S... * aperture the tongue is restrained from moving linearly relative to the : it buckle.
14. A wheelchair restraint strap or restraint as claimed in any one of the preceding claims wherein said one at least one degree of rotational freedom is rotation about a first axis passing through the centre of the spherical or part spherical head.
15. A wheelchair restraint strap or restraint as claimed in claim 14 wherein, in addition to said rotation, the tongue is permitted to move in a further two degrees of rotational freedom about mutually orthogonal axes, each of which are perpendicular to the first axis.
16. A wheelchair restraint strap or restraint substantiafly as described herein with reference to the drawings. * * * * S * ** * *** * * * ***

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****.* * * a a.. a * * * *.

a... * a. ** S* S * S