AU727345B2 - Collapsible chair - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Address for service is: LENDAL PTY LTD WRAY ASSOCIATES 239 Adelaide Terrace Perth, WA 6000 Attorney code: WR c r Invention Title: "Collapsible Chair" Details of Associated Provisional Application No: PN5132 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- THIS INVENTION relates to chairs. More particularly, the invention relates to collapsible chairs which have an assembled condition for normal use and a collapsed condition for transportation and storage.

The invention has been devised particularly, although not solely, for wheelchairs.

It is common for chairs, and in particular wheelchairs, to be of a collapsible construction to allow the chairs to be collapsed for ease of transportation and storage.

A common way for a chair to be collapsible is to construct the chair in detachable upper and lower portions. The upper portion provides support for an occupant of the chair and generally includes a seat and backrest. The lower portion provides a base onto which the upper portion is detachably mountable. In the case of a wheelchair, the lower portion includes wheels to provide mobility to the chair.

With such a collapsible chair, it is highly desirable that the upper portion can be quickly and conveniently attached to the lower portion for assembling the chair and detached from the lower portion for collapsing the chair.

The present invention seeks to provide such a chair.

The present invention provides a collapsible chair comprising an upper section, a lower section, and a securing means for detachably securing the upper section onto the lower section, the securing means including an upper means on the upper section for co-operating with a lower means on the lower section upon relative displacement therebetween to secure the upper and lower sections together against separation, and a restraining means operable between the upper and lower sections for selectively restraining the upper and lower sections against relative displacement in a reverse direction which would allow separation therebetween, the restraining means being operable between the upper and lower sections to bias them in the direction of the relative displacement for maintaining the upper and lower sections in a condition in which they are secured together.

The upper section preferably forms part of an occupant supporting portion of the chair. The lower section preferably forms part of a base for carrying the occupant supporting portion.

The restraining means may comprise an engaging element mounted on one of the upper and lower sections for guided movement relative thereto into and out of an engaging position whereby in the engaging position the engaging element is adapted to engage with the other of said upper and lower sections for biasing the two sections in the direction of said relative displacement, and means for selectively moving the engaging element into and out of the engaging position.

The engaging element may comprise a resiliently flexible pad.

The means for moving the engaging element into and out of engaging position may comprise an extensible mechanism so arranged that extension thereof effects movement of the engaging element towards the engaging position.

The extensible mechanism may comprise an articulated linkage and a control handle operably connected to the linkage for causing angular movement thereof.

The control handle may extend beyond said one of the upper and lower sections when the engaging element is out of the engaging position. This facilitates ease of access to the handle.

The handle may be configured such that the outer end thereof projects further beyond the upper and lower sections when the engaging element is out of the engaging position as compared to when it is in the engaging position. This is of benefit as it provides a visual indication of whether the engaging element has been moved into the engaging position.

-4- A locking device may be provided for releasably locking the handle in a position corresponding to the engaging position of the engaging element. The locking device may comprise a detent against which the handle is releasably locatable when the engaging element is in the engaging position.

The lower means of said securing means may comprise a recess configured to receive the upper means upon said relative displacement between the upper and lower sections. The recess may have an opening transverse to the direction of relative displacement between the upper and lower sections such that the upper means can enter the recess on said relative movement and leave the recess on reverse relative movement.

The upper means of said securing means may comprise a portion of a frame structure of the upper section, such as a frame section or a tab on the frame structure.

Conveniently, there are several of such upper and lower means. An ancillary locking means may be provided for releasably locking the or at least one of the upper means in the or a respective one of the lower means.

The invention will be better understood by reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which: 20 Fig. 1 is a schematic side view of a collapsible wheelchair according to the embodiment shown in an assembled condition; 2 is a view similar to Fig. 1 with the exception that the wheelchair is shown in a collapsed condition; Fig. 3 is a schematic view of upper and lower sections of a frame structure forming part of the wheelchair, the upper and lower sections being adapted to be detachably secured together and being shown in the detached condition; Fig. 4 is a schematic front view of the upper and lower sections shown in the detached condition; Fig. 5 is a schematic side view of the upper and lower sections shown in the detached condition; Fig. 6 is a perspective view of the upper and lower sections in a condition in which they are attached to each other; Fig. 7 is a schematic front view of the upper and lower sections in the attached condition; Fig. 8 is a schematic side view of the upper and lower sections in the attached condition; Fig. 9 is a schematic plan view of the upper and lower sections in the attached condition; and Fig. 10 is a sectional side view of the upper and lower sections in the attached condition.

The embodiment shown in the drawings is directed to a collapsible wheelchair having an occupant supporting portion 11 which is detachably mounted on a mobile base structure 13.

•ell 20 The occupant supporting section 11 comprises a seat 15, a backrest 17 and armrests 19. The seat 15 comprises a cushioned seat portion 21 supported on a seat frame structure 23.

The mobile base structure 13 comprises a base frame structure 25 supported on wheels 27.

A securing arrangement 30 is provided for releasably securing the occupant supporting portion 11 onto the mobile base structure 13. This provides the wheelchair with an assembled condition (as shown in Fig. 1) in which the occupant supporting portion 11 is secured onto the mobile base structure 13, and a collapsed condition (as shown in Fig. 2) in which the occupant supporting portion 11 is detached from the mobile base structure 13. The collapsed condition facilitates transportation and storage of the wheelchair.

The securing arrangement 30 comprises an upper section 31 forming part of the seat frame structure 23 and a lower section 32 forming part of the base frame structure 25 of the mobile base structure 13.

The lower section 32 comprises a generally rectangular frame 33 having two longitudinal side frame sections 35, a transverse front section 37 and a transverse rear frame section 39. The rectangular frame 33 includes a generally horizontal peripheral web 41 surrounding a central opening 43, and a generally upstanding peripheral web 45 surrounding the horizontal web 41. This arrangement provides the frame 33 with a base 51 defined by the horizontal web 41 and a surrounding wall 53 defined by the upstanding web 45. The surrounding wall 53 includes a front wall section 55, a rear wall section 57 and two side wall sections 59. The side wall sections 59 are higher than the front and rear wall 20 sections 55 and 57 respectively. The rear wall section 57 merges with the base .ooo 51 in a curved fashion which presents an arcuate inner surface 61, as best seen in Fig. 10. The rear wall section 57 also has an outwardly extending flange 61 at itsupperend.

A plate 65 is mounted on the rear wall section 57 and extends inwardly thereof, as best seen in Figs. 6 and 10. The inner end of the plate 65 has an upturned section 67.

The lower section 32 includes a rear recess 71 and two front recesses 73, one in which side wall section 59. The rear recess 71 comprises a channel 74 extending across the frame 33 between the side wall sections 59 and is defined between -7the plate 65, rear wall section 57 and the base 51. This provides the rear recess 71 with a forwardly facing opening Each front recess 73 comprises a slot 77 having an entry 79 at the forward end thereof which opens onto the top edge of the respective side wall section 59.

A spring-loaded locking element 81 is associated with each slot 77 at the entry 79, the purpose of which will be explained later. Each locking element 81 is pivotally mounted on the respective side wall section 59 and has an extension section 82 to allow it to be manually manipulated.

The upper section 31 comprises a frame 83 forming part of the seat frame structure 23. The frame 83 is of generally rectangular configuration and includes a transverse front frame section 85, a transverse rear frame section 87, and two longitudinal side frame sections 89 extending between the front and rear frame sections. The frame 83 also includes an intermediate longitudinal frame section 91 extending between the front and rear frame sections.

The frame further comprises two engaging tabs 93, each projecting outwardly sideways from a respective one of the two side frame sections 89. Each tab 93 is dimensioned to be received in the entry 79 of one of the front recesses 73 and to slide sideways alongthe slot 77 thereof, as will be explained later.

This arrangement provides a securing means 95 for releasably securing the upper and lower sections 31,32 together. The securing means 95 comprises an upper means defined by the rear frame section 87 and the tabs 93 on the upper section 31, and a lower means defined by the rear recess 71 and two front recesses 73 on the lower section 32. The rear frame section 87 is adapted to be received in the rear recess 71, and the two tabs 93 are adapted to be respectively 25 received in the two front recesses 73, thereby securing the upper section 31 to the lower section 32. This is achieved by relative displacement of the upper and lower sections 31, 32 along the fore-and-aft direction of the wheelchair.

Specifically, the upper section 31 is secured to the lower section 32 by first -8positioning it on the lower section such that the frame 83 rests on the base 51 with each of the tabs 93 received in the entry 79 of its respective recess 73 and the rear frame section 87 aligned with the rear recess 71. The spring-loaded locking elements 81 deflect downwardly to permit the tabs 93 to enter the slots 77. The upper section 31 is then displaced rearwardly with respect to the lower section 32 so as to move the rear frame section 87 into engagement with the rear recess 71 and slide the tabs 93 sidewardly along the slots 77 to effect engagement with the front recesses 73.

Once the tabs 93 have moved along the slots 77 away from the entries 79 thereof, the spring-loaded locking elements 81 return to their uppermost position to prevent return movement of the tabs 93. The spring-loaded locking elements 81 must be manually deflected downwardly before the tabs 93 can be released from engagement with the front recesses 73.

The spring-loaded locking elements 81 provide safety-catches which serve to releasably maintain the upper and lower sections 31, 32 in engagement with each other. This supplements, and indeed is secondary to, a restraining means 101 which is operable between the upper and lower sections 31, 32 for selectively restraining them against relative movement in the reverse direction (which in this case is forward movement of the upper section 31 relative to the lower section 20 32) The restraining means 101 comprises an engaging element 103 in the form of a rubber pad. The engaging element 103 is mounted for guided movement into and out of an engaging position. More particularly, the engaging element 103 is mounted on the outer end of a shaft 105 which is slidably supported in a sleeve 107 mounted on the front frame section 85 of the frame 83. The shaft 105 is mounted for reciprocal movement in the sleeve 107 under the control of an extensible means 109 which is operably connected between the inner end of the shaft 105 and the intermediate longitudinal frame section 91 of the frame 83. The extensible means 109 comprises an articulated linkage having a first link 111 and 30 a second link 112 pivotally connected together at 113. The first link 111 is -9pivotally connected at 115 to the rear end of the shaft 105 and the second link 112 is pivotally connected at 117 to a bracket 119 mounted on the intermediate longitudinal frame section 91. With this arrangement, angular movement of the articulated linkage causes reciprocal movement of the shaft 105 with respect to the sleeve 107 and thereby moves the engaging element 103 into and out of the engaging position.

A handle 121 is attached at one end thereof to the second link 112 such that manipulation of the handle effects angular movement of the articulated linkage.

The handle 121 extends forwardly beyond the front frame section 85 and is curved to provide a lateral portion 123 at the outer end thereof. A knob 125 is fitted onto the free end of the handle to make the handle easier to grasp.

The orientation of the lateral portion 123 is such that the knob follows an arcuate path from an outermost position away from the frame 83 (as best seen in Fig. 3) which position corresponds to the rearward most position of the engaging element 103 away from the engaging position and an innermost closely adjacent the frame 83 (as best seen in Figs. 6 and 9) which position corresponds to the engaging position of the engaging element 103.

The upper surface of the front wall section 55 of the frame 33 is provided with a detent 127 for releasably securing the handle 121 in the position corresponding to 20 the engaging position of the engaging element 103.

S.:2 The engaging element 103 is adapted to engage against the front wall section of the rectangular frame 33 provided by the lower section 32 when it is in the engaging position. This provides a reaction for between the upper and lower sections 31, 32 in the direction of the relative displacement so as to maintain the upper means defined by the rear frame section 87 and the tabs 93 on the upper section 31 in securing engagement with the lower means defined by the rear recess 31 and the two front recesses 73 on the lower section 32.

S

When the upper section 31 is positioned on the lower section 32, it is visually apparent whether the engaging element 103 is in the engaging position by the relative position of the handle 121. If the handle is not in the position closely adjacent the frame 83 retained by the detent 127, it is then apparent that the engaging element 103 is not properly in the engaging position.

The securing means 95 provides an effective yet convenient way for releasably securing the upper and lower sections 31 and 32 together. To secure the upper section 31 onto the lower section 32, all that is necessary is to position the upper section 31 on the lower section 32 such that the frame 83 rests on the base 41 with each of the tabs 93 received in the entry 79 of its respective recess 73 and the rear frame section 87 aligned with the rear recess 71. As the upper section 31 is located into such a position, the spring-loaded locking elements 81 deflect downwardly to permit the tabs 93 to enter the slots 77. The upper section 31 is then displaced rearwardly with respect to the lower section 32 so as to move the 15 rear frame section 87 into engagement with the rear recess 71 and simultaneously slide the tabs 93 along the slots 77 to effect engagement with the front recesses 73. The handle 121 is then operated to move the engaging element 103 towards the engaging position at which it engages against the front wall section 55 of the rectangular frame 33 of the lower section 32. Such 20 engagement urges the upper section 31 rearwardly with respect to the lower ~section 32 so as to maintain engagement between the tabs 93 and respective slots 77 and the rear frame section 87 with the rear recess 71. The handle engaging element 103 is locked into the engaging position by securing the handle in position against the detent 127. The chair is now in the assembled, condition ready for use. To collapse the chair, the handle 121 is operated to move the engaging element 103 out of engagement with the lower section 32. The springloaded locking elements 81 are manually operated to move them into their downward position so as to allow the tabs 93 to slide along the slots 77 and move out of engagement with the front recesses 73 on displacement of the upper section 31 in the forward direction with respect to the lower section 32. At the same time, the rear frame section 87 moves out of engagement with the rear -11 recess 71. This releases the upper section 31 from the lower section 32, thereby allowing the occupant supporting portion 10 of the wheelchair to be separated from the mobile base structure 13.

From the foregoing description of the embodiment, it is evident that the present invention provides a chair which can readily be assembled and collapsed in a convenient manner.

It should be appreciated that the scope of the invention is not limited to the scope of the embodiment described.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims (17)

1. A collapsible chair comprising an upper section, a lower section, and a securing means for detachably securing the upper section onto the lower section, the securing means including an upper means on the upper section for co-operating with a lower means on the lower section upon relative displacement therebetween to secure the upper and lower sections together against separation, and a restraining means operable between the upper and lower sections for selectively restraining the upper and lower sections against relative displacement in a reverse direction which would allow separation therebetween, the restraining means being operable between the upper and lower sections to bias them in the direction of the relative displacement for maintaining the upper and lower sections in a condition in which they are secured together.

2. A collapsible chair according to claim 1 wherein the upper section forms part of an occupant supporting portion of the chair.

3. A collapsible chair according to claim 1 or 2 wherein the lower section forms part of a base for carrying the occupant supporting portion.

4. A collapsible chair according to any one of the preceding claims wherein the restraining means comprises an engaging element mounted on one of the upper and lower sections for guided movement relative thereto into and out of an engaging position whereby in the engaging position the engaging element is adapted to engage with the other of said upper and lower sections for biasing the two sections in the direction of said relative displacement, and means for selectively moving the engaging element into and out of the engaging position.

A collapsible chair according to claim 4 wherein the engaging element comprises a resiliently flexible pad. -13-

6. A collapsible chair according to claim 4 or 5 wherein the means for moving the engaging element into and out of engaging position comprises an extensible mechanism so arranged that extension thereof effects movement of the engaging element towards the engaging position.

7. A collapsible chair according to claim 6 wherein the extensible mechanism comprises an articulated linkage and a control handle operably connected to the linkage for causing angular movement thereof.

8. A collapsible chair according to claim 7 wherein the control handle extends beyond said one of the upper and lower sections when the engaging element is out of the engaging position.

9. A collapsible chair according to claim 8 wherein the handle is so configured that the outer end thereof projects further beyond the upper and lower sections when the engaging element is out of the engaging position as compared to when it is in the engaging position.

10. A collapsible chair according to any one of claims 7, 8 or 9 wherein a locking device is provided for releasably locking the control handle in a position corresponding to the engaging position of the engaging element.

11. A collapsible chair according to claim 10 wherein the locking device comprises a detent against which the control handle is releasably locatable when the engaging element is in the engaging position.

12. A collapsible chair according to any one of the preceding claims wherein the lower means of said securing means comprises a recess configured to receive the upper means upon said relative displacement between the upper and lower sections.

13. A collapsible chair according to claim 12 wherein the recess has an opening transverse to the direction of relative displacement between the upper and -14- lower sections such that the upper means can enter the recess on said relative movement and leave the recess on reverse relative movement.

14. A collapsible chair according to any one of the preceding claims wherein the upper means of said securing means comprises a portion of a frame structure of the upper section, such as a frame section or a tab on the frame structure.

A collapsible chair according to any one of the preceding claims comprising a plurality of the upper and lower means.

16. A collapsible chair according to claim 1 or 15 wherein a locking means is provided for releasably locking the or at least one of the upper means in the or a respective one of the lower means.

17. A collapsible chair substantially as herein described with reference to the accompanying drawings. DATED this TWELFTH day OCTOBER 2000 LENDAL PTY LTD Applicant WRAY ASSOCIATES Perth, Western Australia Patent Attorneys for Applicant