EP2906171B1

EP2906171B1 - Quick release device for a wheelchair

Info

Publication number: EP2906171B1
Application number: EP12797974.8A
Authority: EP
Inventors: Simon Brenner; Bernard Nicolas
Original assignee: Invacare International SARL
Current assignee: Invacare International SARL
Priority date: 2012-10-09
Filing date: 2012-10-09
Publication date: 2016-12-07
Anticipated expiration: 2032-10-09
Also published as: EP2906171A1; WO2014057306A1

Description

Technical Field

The present invention relates to a quick release device adapted to removably connect together a first and a second longitudinal tubes of a wheelchair.
The present invention relates also to a wheelchair that can be easily and quickly dissociated so as to permit it to be easily placed inside an automobile or other suitable conveyance.

Prior Art and the Problem Underlying the Invention

The portability of a wheelchair is an important consideration to many wheelchair users. In particular, it is often desirable that a wheelchair be easily broken down so that it can readily and conveniently transported in an automobile or other suitable conveyance. One known solution to this problem consists in assembling different parts of the wheelchair with quick release assemblies that can be locked and unlocked without any tools, thereby allowing the user to easily make such a disassembling operation. However, such quick release assemblies do not securely connect together the different parts of the wheelchair. Indeed, a risk exists that the user inadvertently forgets to position the quick release assemblies in their locking position. In this case, two parts connected by such quick release assemblies may therefore be disconnected when the user is sitting in the wheelchair. If such a disconnection occurs when the wheelchair is running fast and if said parts correspond to frames which are supported on the ground by the rear wheels and the caster wheels respectively, such an event may lead to dramatic consequences for the user.
US 2009/194974 discloses a foldable wheelchair comprising a locking mechanism.
Thus, a first objective of the present invention is to provide a quick release device specifically designed so as to prevent an accidental disengagement of the parts of the wheelchair that are connected together by said quick release device.
A second objective of the present invention is to provide a quick release device that can be adapted to various wheelchair configurations without significant modification of the wheelchair.
A third objective of the present invention is to provide a wheelchair in which two frames supported on the ground by the rear wheels and the caster wheels respectively are removably and securely connected together.

Summary of Invention

In an aspect, the present invention provides a quick release device adapted to removably connect together a first and a second longitudinal tubes of a wheelchair, said quick release device comprising:

a first tubular element fixedly connected to said first longitudinal tube;
a second tubular element fixedly connected to said second longitudinal tube, said second tubular element being adapted to be telescopically received inside said first tubular element;
a clamping assembly adapted to clamp said first tubular element on said second tubular element to prevent an axial movement of said second tubular element relative to said first tubular element, said clamping assembly comprising:
a C-shaped ring integral with or adapted to house an end portion of said first tubular element through which is inserted said second tubular element, said ring having two opposite projections delimiting a longitudinal slit extending along its whole length, said projections being provided with through-holes defining a first axial direction;
a locking rod extending through said through-holes and having a first and a second ends extending outside said ring, said first end being fixedly connected to a nut and said second end being fixedly connected to a pivot element defining a second axial direction;
a lever having a handle end and a pivot end, said pivot end having a cavity adapted to receive said pivot element and being configured so as to pivotally connect the lever to the locking rod around said first and second axial directions;
wherein said pivot end is configured so as to force said projections toward one another when said lever pivots around said second axial direction from an open position to a closed position, thereby clamping said first tubular element against said second tubular element;
wherein said locking rod is configured so as to be positioned, in a locking position of said lever, at least partially inside a groove provided in the outer surface of said second tubular element, thereby preventing the axial movement of said second tubular element relative to said first tubular element, and, in an unlocking position of said lever, outside said groove, thereby permitting the axial movement of said second tubular element relative to said first tubular element, whereby the second tubular element has a conical-shaped end adapted to bear against a conical-shaped shoulder of a flexible sleeve provided with a plurality of longitudinal slits, said sleeve being slidably received inside said first tubular element and urged against said conical-shaped end by resilient means, thereby limiting or, preferably, eliminating the play between said first tubular element and said second tubular element.

Further aspects and preferred embodiments are provided in the appended claims.
Thus configured, the quick release device according to the invention permits to removably connect together the first longitudinal tube and the second longitudinal tube and prevents an accidental disengagement of said tubes when the user forgets to position the lever in its closed position. Indeed, if the lever is maintained in its locking position, the locking rod prevents an axial movement of the second longitudinal tube, fixedly connected to the second tubular element, relative to the first longitudinal tube, fixedly connected to the first tubular element.

Brief Description of the Drawings

The wheelchair of the present invention will be described in further detail further below, when useful with reference to the attached drawings, which show an exemplary wheelchair frame according to the invention.

Figure 1 is a perspective view of a wheelchair according to an embodiment of the present invention, the wheelchair being in its normal position of use.
Figure 2 is a similar view to that of Figure 1, the front frame being disconnected from the seat frame.
Figure 3 is a similar view to that of Figure 1, the wheelchair being in its position of transport.
Figure 4 is an exploded perspective view of the quick release device that connects the front frame and the seat frame of the wheelchair of Figure 1 at their right side.
Figure 5 is a longitudinal sectional view of the quick release device of Figure 4, in the locking and closed position of the lever, when connected to the first longitudinal tube.
Figure 6a is a perspective view of the quick release device of Figure 4, in the locking and closed position of the lever, the second tubular element being not shown.
Figure 6b is a similar view to that of Figure 6a, the C-shaped ring and the first tubular element being not shown.
Figure 7a is an end view of the clamping assembly of the quick release device of Figure 6a.
Figure 7b is an enlarged view of the detail A of Figure 7a.
Figure 8a is a perspective view of the quick release device of Figure 4, in the unlocking and open position of the lever, the second tubular element being not shown.
Figure 8b is a similar view to that of Figure 8a, the C-shaped ring and the first tubular element being not shown.
Figure 9a is an end view of the clamping assembly of the quick release device of Figure 8a.
Figure 9b is an enlarged view of the detail A of Figure 9a.
Figure 10 is an enlarged perspective view of the lever of the quick release device of Figure 4.
Figure 11 is an enlarged perspective view of the spacer ring of the quick release device of Figure 4.

Detailed Description of the Preferred Embodiment

For the purpose of the present specification, situations and directions of elements of the wheelchair of the present invention are determined by the perspective of a user seated in the wheelchair. Accordingly, the rear side of the wheelchair corresponds to the top right side of Figure 1. The situations or directions "up" or "top" and "down" or "bottom", "rear" or "back" and "front", "behind" and "in front", "upper" and "lower", "lateral" and "central" follow the same rule. A longitudinal direction corresponds to a back-to-front direction and a lateral direction corresponds to a left-to-right direction. The terms "forward" or "forwardly" and "rearward" or "rearwardly" refer to the direction of motion of the wheelchair. The horizontal corresponds to the plane tangential to the rear and front wheels and positioned under said wheels when the wheelchair is its normal position of use. A horizontal plane corresponds to a plane parallel to the horizontal. The vertical, or a vertical plane, corresponds to a plane perpendicular to the horizontal.
Figure 1 shows a wheelchair according to the present invention. Apart that the wheelchair 100 comprises a quick release device 10 according to the present invention, said wheelchair 100 is almost identical to the wheelchair that was disclosed in the European patent application no. 11194954.7 filed by the Applicant, the content of which is integrated by reference into the present application. The wheelchair 100 comprises a main frame 110 and a front frame 120 removably connected thereto. The main frame 110 is supported on the ground by left and right rear wheels 111a and 111b and the front frame 120 is supported on the ground by left and right front wheels 121a and 121b. The front wheels 121a, 121b are preferably casters and the rear wheels 111a, 111b are preferably drive wheels, which may be manually driven or power driven. The main frame 110 includes a seat frame 112 and a backrest frame 114. The seat frame 112 includes longitudinally extending frame profiles, such as left and right tubes 118a and 118b, for supporting a seat plate 116, which may preferably be in the form of a semi-rigid or rigid pan integral with said tubes 118a and 118b, as shown. Said left and right tubes 122a and 122b of the front frame 120 are removably connected to said left and right tubes 118a and 118b of the seat frame 112 via left and right quick release devices 10.
As shown in Figures 4 and 5, each quick release device 10 comprises a first tubular element 12 slidably received inside and fixedly connected to one of the tubes 118a or 118b of the seat frame 112, preferably via screws (not shown) adapted to be received inside bores of the first tubular element 12 and the tube 118a or 118b respectively. In particular, the first tubular element 12 may advantageously comprise a first series of spaced-apart, longitudinally extended bores 13 disposed along the left side thereof and a second series of spaced-apart, longitudinally extended bores 13 disposed along the right side thereof, said bores 13 being adapted to be aligned with corresponding spaced-apart, longitudinally extended bores 113 provided in the tube 118a or 118b and receive the threaded rod of a screw such that said first tubular element 12 can be fixedly connected to said tube 118a or 118b. The quick release device 10 comprises also a second tubular element 14 fixedly connected to one of the tubes 122a or 122b of the front frame 120, said second tubular element 14 being adapted to be telescopically received inside said first tubular element 12. To limit or, preferably, eliminate the play between the first tubular element 12 and the second tubular element 14, said second tubular element 14 has a conical-shaped end 14a adapted to bear against a conical-shaped shoulder 16a of a flexible sleeve 16 provided with a plurality of longitudinal slits 16b extending along a portion of its length, said sleeve 16 being slidably received inside said first tubular element 12 and urged against said conical-shaped end 14a by resilient means. In the embodiment shown, the resilient means consists in a coil spring 18, one rear end thereof abutting against an abutment provided inside the tube 118a or 118b and one front end thereof abutting against a rear end 16c of the flexible sleeve 16. The second tubular element 14 has also a thin annular portion 14c disposed along its length, said annular portion 14c having a higher outer diameter relative to the outer diameter of the front end of said tubular element 14 so as to define an abutment against which abuts that the second longitudinal tube 122a or 122b when said second tubular element 14 is correctly positioned inside said second longitudinal tube 122a or 122b.
The quick release device 10 comprises also a clamping assembly 20 adapted to clamp the first tubular element 12 on the second tubular element 14, thereby preventing an axial movement of said second tubular element 14 relative to said first tubular element 12, and, thus, preventing an axial movement of the tube 122a, respectively 122b, of the front frame 120 relative to the tube 118a, respectively 118b, of the seat frame 112. In the embodiment shown, this clamping assembly 20 comprises a C-shaped ring 21 integral with an end portion 12a of the first tubular element 12 through which is inserted the second tubular element 14, said ring 21 having two opposite projections, respectively an upper projection 21a and a lower projection 21b, delimiting a longitudinal slit 21c extending along its whole length, said projections 21a, 21b being respectively provided with through-holes 21e, 21f defining a first axial direction XX'. In the embodiment shown, said first axial direction XX' is vertical or substantially vertical. Furthermore, the end portion 12a is advantageously provided with a longitudinal slit 12a₁ substantially aligned with the slit 21c so that the internal diameter of the end portion 12a can be reduced when the projections 21a, 21b are forced toward one another. In a further embodiment (not shown) of the present invention, the ring 21 may be separate from the first tubular element 12. In this case, the ring 21 may be adapted to house the end portion 12a of the first tubular element 12 and the end portion 12a may be provided with upper and lower through-holes aligned with the through-holes 21e, 21f of the ring 21 when said ring 21 is correctly positioned relative to said end portion 12a.
The clamping assembly 20 comprises also a locking rod 22 extending through said through-holes 21 e, 21f and having an upper and a lower ends 22a, 22b extending outside the ring 21, said upper end 22a being threadedly connected to a nut 23, said nut 23 abutting against an upper face of the upper projection 21a, and said lower end 22b being fixedly connected to a cylindrical-shaped pivot element 24 defining a second axial direction YY', said pivot element 24 being received into a cylindrical-shaped cavity 25a₁ provided in a pivot end 25" of a lever 25 and said locking rod 22 extending through an arc-shaped aperture 25a₂ provided in said pivot end 25" and leading to said cavity 25a₁. In the embodiment shown, said second axial direction YY' is horizontal or substantially horizontal. Thus configured, the lever 25 can pivot around the first and second axial directions XX' and YY' when the user moves the lever 25 via its handle end 25'. In particular, and as better explained in the following paragraphs, several successive movements of the lever 25 can be done so as to disengage the second tubular element 14 from the first tubular element 12. The user can firstly pivot the lever 25 around the second axial direction YY' in the clockwise direction (when seen from the left side of the wheelchair) from a closed locking position (as illustrated in Figures 1 and 6a), in which its handle end 25' is substantially horizontal and rearwardly oriented, the upper face 25b thereof being upwardly oriented, to an open locking position (not shown), in which said handle end 25' is substantially vertical and downwardly oriented, said upper face 25b being rearwardly oriented. During this movement, the lever 25 pivots by an angle substantially equal to 90° around the second axial direction YY'. Thereafter, the user can pivot the lever 25 around the first axial direction XX' from said open locking position to an open unlocking position, as illustrated in Figure 8a, in which its handle end 25' is substantially vertical and downwardly oriented, the upper face 25b being forwardly oriented. During this movement, the lever 25 pivots by an angle substantially equal to 180° around the first axial direction XX'. Finally, the user can pivot the lever 25 around the second axial direction YY' from said open unlocking position to a closed unlocking position, as illustrated in Figure 2, in which its handle end 25' is substantially horizontal and forwardly oriented, the upper face 25b being upwardly oriented. During this movement, the lever 25 pivots by an angle substantially equal to 90° around the second axial direction YY'. In the open unlocking position of the lever 25, the second tubular element 14 is disconnected from the first tubular element 12 and is free to move along the longitudinal direction, as illustrated in Figure 2, thereby permitting the disassembling of the front frame 120. Thereafter, the wheelchair 100 can be positioned in its position of transport, as illustrated in Figure 3, in which the drive wheels 111a and 111b are disconnected from the main frame 110 and the backrest frame 114 are folded so as to be positioned parallel and close to the seat frame 112. In this position, the front frame 120 can be positioned under the seat frame 112 so that the dimensions of the wheelchair 100 are highly reduced.
As better explained in the following paragraphs, when the lever 25 pivots around the second axial direction YY' from the open locking, respectively unlocking, position to the closed locking, respectively unlocking, position, the pivot end 25" is configured so as to force the projections 21a, 21b of the ring 21 toward one another, thereby clamping the first tubular element 12 against the second tubular element 14. Furthermore, when the lever 25 pivots around the first axial direction XX' from the open locking position to the open unlocking position, the locking rod 22 moves from a first position, in which it is positioned at least partially inside a groove 14b₁ provided in the outer surface of an annular portion 14b of the second tubular element 14, thereby preventing the axial movement of the second tubular element 14 relative to the first tubular element 12, to a second position, in which it is positioned outside said groove 14b₁, thereby permitting the axial movement of the second tubular element 14 relative to the first tubular element 12. Thus configured, the quick release device 10 permits to removably connect together the tube 122a, respectively 122b, to the tube 118a, respectively 118b, and prevents an accidental disengagement of said tubes 118a, 122a, respectively 118b, 122b, when the user forgets to position the lever 25 in its closed locking position illustrated in Figure 6a. Indeed, if the lever 25 is maintained in its open locking position, the locking rod 22 prevents an axial movement of the tube 122a, respectively 122b, fixedly connected to the second tubular element 14, relative to the tube 118a, respectively 118b, fixedly connected to the first tubular element 12.
Further details relative to the clamping assembly 20 are illustrated in Figures 6a to 11.
As illustrated in Figures 6a, 6b and 7a, 7b, when the lever 25 is in its closed (as shown) or open locking position, a recess 22c₁ provided in a central section 22c of the locking rod 22 extends at least partially inside the slit 21c separating the projections 21a and 21b of the ring 21, said central section 22c being positioned at least partially inside an approximately cylindrical aperture 21g of the ring 21, said aperture 21g being adapted to receive the annular portion 14b of the second tubular element 14 that is provided with the groove 14b₁. Therefore, when the second tubular element 14 is correctly positioned inside the first tubular element 12, said groove 14b₁ is positioned in front of the slit 21c, thereby permitting to position the central section 22c of the locking rod 22 inside said groove 14b₁ when the lever is in its closed or open locking position. Thus, in said closed or open locking position of the lever 25, the second tubular element 14 can not be disengaged from the first tubular element 12.
As illustrated in Figures 8a, 8b and 9a, 9b, when the lever 25 is in its closed or open (as shown) unlocking position, the recess 22c₁ extends at least partially inside the aperture 21g, said central section 22c being positioned outside said aperture 21g. Therefore, when the lever 25 is in its open unlocking position, nothing prevents the second tubular element 14 to axially move relative to the first element 12. Thus, in said open unlocking position of the lever 25, the second tubular element 14 can be disengaged from the first tubular element 12.
As illustrated in Figure 10, the pivot end 25" of the lever is shaped like a clevis and comprises two opposite wings 25 "a, 25 "b provided with through-holes 25"a₁, 25"b₁ so as to allow the positioning of the pivot element 24, said wings 25"a, 25"b having an approximately oblong shape and said pivot element 24 being positioned relative to said wings 25 "a, 25 "b so as to define an eccentric. Thus configured, the pivot end 25" defines a cam surface that causes the nut 23 to be pulled toward the lever 25 as the lever 25 moves from its open locking, respectively unlocking, position to its closed locking, respectively unlocking, position, thereby forcing the projections 21a, 21b toward one another. The wings 25"a, 25"b are rounded at their periphery and resting on a spacer ring 26, illustrated in Figure 11, positioned between the lever 25 and the C-shaped ring 21 along the locking rod 22, the surface of said spacer ring 26a which is in contact with said wings 25 "a, 25"b having a rounded profile adapted to receive said wings and permit the pivoting movement of said lever around the second axial direction YY' between its open locking, respectively unlocking, position and its closed locking, respectively unlocking, position.
The above detailed description with reference to the drawings illustrates rather than limit the invention. There are numerous alternatives, which fall within the scope of the appended claims.

Claims

A quick release device (10) adapted to removably connect together a first and a second longitudinal tubes (118a, 122a; 118b, 122b) of a wheelchair (100), said quick release device comprising:
- a first tubular element (12) fixedly connectable to said first longitudinal tube (118a, 118b);

- a second tubular element (14) fixedly connectable to said second longitudinal tube (122a, 122b),
said second tubular element being adapted to be telescopically received inside said first tubular element;

- a clamping assembly (20) adapted to clamp said first tubular element (12) on said second tubular element (14) to prevent an axial movement of said second tubular element (14) relative to said first tubular element (12), said clamping assembly comprising:
- a C-shaped ring (21) integral with or adapted to house an end portion (12a) of said first tubular element (12) through which is inserted said second tubular element (14), said ring having two opposite projections (21a, 21b) delimiting a longitudinal slit (21c) extending along its whole length, said projections being provided with through-holes (21e, 21f) defining a first axial direction (XX');

- a locking rod (22) extending through said through-holes (21 e, 21f) and having a first and a second ends (22a, 22b) extending outside said ring (21), said first end (22a) being fixedly connected to a nut (23) and said second end (22b) being fixedly connected to a pivot element (24) defining a second axial direction (YY');

- a lever (25) having a handle end (25') and a pivot end (25"), said pivot end (25") having a cavity (25a₁) adapted to receive said pivot element (24) and being configured so as to pivotally connect the lever (25) to the locking rod (22) around said first and second axial directions (XX', YY');
wherein said pivot end (25") is configured so as to force said projections (21a, 21b) toward one another when said lever (25) pivots around said second axial direction (YY') from an open position to a closed position, thereby clamping said first tubular element (12) against said second tubular element (14);
wherein said locking rod (22) is configured so as to be positioned, in a locking position of said lever (25), at least partially inside a groove (14b₁) provided in the outer surface of said second tubular element (14), thereby preventing the axial movement of said second tubular element (14) relative to said first tubular element (12), and, in an unlocking position of said lever (25), outside said groove (14b₁), thereby permitting the axial movement of said second tubular element (14) relative to said first tubular element (12),
characterised in that the second tubular element (14) has a conical-shaped end (14a) adapted to bear against a conical-shaped shoulder (16a) of a flexible sleeve (16) provided with a plurality of longitudinal slits (16b), said sleeve (16) being slidably received inside said first tubular element (12) and urged against said conical-shaped end (14a) by resilient means (18), thereby limiting or, preferably, eliminating the play between said first tubular element (12) and said second tubular element (14).
The quick release device (10) of claim 1, wherein the movement of the lever (25) from its locking position to its unlocking position occurs when it pivots around the first axial direction (XX') from its open position.
The quick release device (10) of claim 2, wherein the movement of the lever (25) from its locking position to its unlocking position occurs when it pivots by an angle substantially equal to 180 degrees around the first axial direction (XX') from its open position.
The quick release device (10) of any one of the preceding claims, wherein the ring (21) comprises an approximately cylindrical aperture (21g) adapted to receive the second tubular element (14) and wherein the locking rod (22) comprises at least one central section (22c) having a recess (22c₁), said central section (22c) being configured so as to be positioned, in the locking position of the lever (25), at least partially inside said aperture (21g), said recess (22c₁) extending at least partially inside the slit (21c) separating the projections (21a, 21b) of the ring (21), and, in the unlocking position, outside said aperture (21g), said recess (22c₁) extending al least partially inside said aperture (21g).
The quick release device (10) of any one of the preceding claims, wherein the pivot end (25") of the lever (25) defines a cam surface that causes the nut (23) to be pulled toward the lever (25) as said lever (25) moves from its open position to its closed position, thereby forcing said projections (21 a, 21 b) toward one another.
The quick release device (10) of claim 5, wherein the pivot end (25") is shaped like a clevis and comprises two opposite wings (25"a, 25"b) provided with through-holes (25"a₁, 25"b₁) so as to allow the positioning of the pivot element (24), said wings (25"a, 25"b) having an approximately oblong shape and said pivot element (24) being positioned relative to said wings (25"a, 25"b) so as to define an eccentric.
The quick release device (10) of claim 6, wherein the wings (25"a, 25"b) are rounded at their periphery and resting on a spacer ring (26) positioned between the lever (25) and the C-shaped ring (21) along the locking rod (22), the surface (26a) of said spacer ring (26) which is in contact with said wings (25"a, 25"b) having a rounded profile adapted to receive said wings (25"a, 25"b) and permit the pivoting movement of said lever (25) around the second axial direction (YY') between its open position and its closed position.
The quick release device (10) of claim 1, wherein the resilient means (18) consist in a coil spring, one rear end thereof abutting against an abutment provided inside the first longitudinal tube (118a, 118b) and one front end thereof abutting against a rear end (16c) of the flexible sleeve (16).
The quick release device (10) of any one of the preceding claims, wherein the first tubular element (12) comprises a first series of spaced-apart bores (13) and a second series of spaced-apart bores (13), said bores (13) being adapted to be aligned with corresponding bores (113) provided in the first longitudinal tube (118a, 118b) and receive the threaded rod of a screw such that said first tubular element (12) can be fixedly connected to said first longitudinal tube (118a, 118b).
The quick release device (10) of any one of the preceding claims, wherein the end portion (12a) of the first tubular element (12) is provided with a longitudinal slit (12a₁) substantially aligned with the slit (21c) separating the projections (21a, 21b) of the ring (21) so that the internal diameter of said end portion (12a) can be reduced when said projections (21a, 21b) are forced toward one another.
The quick release device (10) of any one of the preceding claims, wherein the second tubular element (14) has a thin annular portion (14c) disposed along its length, said annular portion (14c) having a higher outer diameter relative to the outer diameter of the front end of said second tubular element (14) so as to define an abutment against which abuts that the second longitudinal tube (122a, 122b) when said second tubular element (14) is correctly positioned inside said second longitudinal tube (122a, 122b).
A wheelchair (100) comprising:
- a seat frame (112) supported on the ground by left and right drive wheels (111a, 111b), said seat frame (112) including first left and right longitudinal tubes (118a, 118b),

- a front frame (120) supported on the ground by left and right caster wheels (121a, 121b), said front frame (120) including second left and right longitudinal tubes (122a, 122b),
wherein said first left and said second left, respectively said first right and said second right, longitudinal tubes (118a, 122a; 118b, 122b) are removably connected together by a left, respectively a right, quick release device (10) according to any one of the preceding claims.
The wheelchair (100) of claim 12, wherein the seat frame (112) supports a rigid or semi-rigid seat plate (116).
The wheelchair (100) of claim 13, wherein the seat plate (116) is integral with the first left and right longitudinal tubes (118a, 118b).