GB2425943A

GB2425943A - Collapsible chair with mechanism to prevent unwanted collapse

Info

Publication number: GB2425943A
Application number: GB0601197A
Authority: GB
Inventors: Ming-Tai Huang
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-20
Filing date: 2006-01-20
Publication date: 2006-11-15
Anticipated expiration: 2026-01-20
Also published as: GB2425943B; GB0601197D0

Abstract

A collapsible chair includes two front legs (11, Fig. 1) two rear legs (12), two armrests (15), a seat frame 13, and backrest frame 14. A linking member 40 is mounted on each rear leg and includes a first end pivoted to an associated backrest frame and a second end pivoted to an associated rear leg. Each linking member is not located on a side of the associated rear leg that faces the associated front leg. One of the linking members includes a stop face 46. A positioning member 50 and a spring 52 are mounted on one of the rear legs. When the collapsible chair is in an extended status, the positioning member is biased by the spring such that a stop (56, Fig. 4) on the positioning member comes into contact with the stop face, preventing collapse of the collapsible chair. The positioning member may be moved against the force of the spring, such that the stop disengages from the stop face, therefore allowing the chain to be collapsed.

Description

1 2425943 Collapsible Chair with Minimized Collapsed Height

Field of the Invention

The present invention relates to a chair, and more particularly to a collapsible chair.

Background of the Invention

A collapsible chair may be collapsed when not in use. A user might be injured when he or she sits in an extended collapsible chair and leans backward, as the front legs of the chair might be moved above the ground to a status allowing collapse of the chair. Further, the user might be injured when collapsing the collapsible chair, as the fingers of the user are placed on the pivotal sections of the collapsible chair. GB Patent No. 2361633 discloses a pinch preventing mechanism for a collapsible chair to prevent injury to the user.

However, the collapsible chair still occupies a considerable space even fully collapsed.

More specifically, referring to Figs. 9 and 10, the collapsible chair disclosed in GB Patent No. 2361633 comprises a pair of front legs 11, a pair of rear legs 12, two armrests 15, a seat frame 13, and a backrest frame 14. The collapsible chair further comprises a pinch preventing mechanism 20 on one of the rear legs 12. The pinch preventing mechanism 20 comprises a sleeve 21 mounted around one of the rear leg 12 and including a locking member 22 that is biased by a spring 25 to securely yet releasably engage with an upper end of an engaging device 30 when the collapsible chair is in an extended status, thereby preventing collapse of the collapsible chair. When collapsing the collapsible chair, the sleeve 21 is manually moved upward, and the spring 25 exerts a downward force to retain the sleeve 21 at a level in which the locking member 22 of the sleeve 21 disengages from the upper end of the engaging device 30, thereby allowing collapse of the collapsible chair. However, the overall height H' of the collapsed chair could not be minimized, as the sleeve 21 is mounted around one of the rear legs 12. More specifically, the thickness of a portion of the sleeve 21 facing the associated front leg 11 prohibits further reduction of the collapsed height H' of the collapsible chair, as shown in Fig. 11.

An object of the present invention is to provide a collapsible chair that has a minimized collapsed height while providing a pinch preventing function.

Summary of the Invention

A collapsible chair in accordance with the present invention comprises: a backrest frame including two lateral sides; a seat frame including two lateral sides each having a rear end pivotally connected to a lower end of an associated one of the lateral sides of the backrest frame, two armrests each comprising a front end and a rear end, the rear end of each armrest being pivotally connected to an intermediate portion of an associated one of the lateral sides of the backrest frame; two front legs each having an upper end pivotally connected to the front end of an associated one of the armrests; two rear legs each having an upper pivotally connected to an intermediate portion of an associated one of the armrests; two linking members respectively mounted on the rear legs, each linking member comprising a first end pivotally connected to the lower end of an associated one of the lateral sides of the backrest frame and a second end pivotally connected to an associated one of the rear legs; characterised in that: each linking member is not located on a side of the associated rear leg that faces the associated front leg; one of the linking members comprises a stop face; a positioning member is mounted on one of the rear legs and comprises a stop, the positioning member is slidable along a longitudinal direction of one of the rear legs; and a spring mounted on the one of the rear legs; wherein when the collapsible chair is in an extended status, the positioning member is biased by the spring to cause the stop to come into contact with the stop face of the one of the linking members, thereby preventing collapse of the collapsible chair; and wherein collapse of the collapsible chair is allowed when the positioning member is moved in a direction such that the stop of the positioning member is disengaged from the stop face of the one of the linking members.

Since each linking member is not located on a side of the associated rear leg that faces the associated front leg, a minimized collapsed height of the collapsible chair can be obtained.

Preferably, each linking member is substantially U-shaped and comprises two arms respectively on two sides of the associated rear leg and an intermediate section between the arms.

Preferably, the intermediate section of each linking member includes a through-hole, and a pin is extended through the through-hole of the intermediate section and through the lower end of the associated lateral side of the backrest frame.

Preferably, the stop face of the one of the linking members extends from the intermediate section and between the arms.

Preferably, the positioning member is fixed by a rivet to the one of the rear legs. The positioning member comprises a wall with a slot. The rivet extends through the slot and the one of the rear legs. The rivet comprises a head locate din the positioning member and spaced from the wall of the positioning member, allowing the positioning member to slide along the longitudinal direction of the one of the rear legs.

Preferably, a spring-abutting member is fixed to the one of the rear legs, and the spring is mounted between the spring-abutting member and an end wall of the positioning member.

Preferably, the positioning member comprises two lateral walls between which the spring-abutting member is located.

Preferably, the stop of the positioning member comprises an inclined face.

Preferably, the positioning member further comprises a thumb-piece for manual operation.

Other objectives, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

Fig. 1 is a perspective view of a collapsible chair in accordance with the present invention.

Fig. 2 is a side view of the collapsible chair in an extended status.

Fig. 3 is a side view, partly sectioned, of a portion of the collapsible chair in accordance with the present invention in the extended status.

Fig. 4 is a perspective view, partly exploded, of the portion of the collapsible chair in Fig. 3.

Fig. 5 is an enlarged view of a portion, partly sectioned, of the collapsible chair being collapsed.

Fig. 6 is a side view similar to Fig. 4, wherein the collapsible chair is being collapsed.

Fig. 7 is a side view of the collapsible chair in a fully collapsed status.

Fig. 8 is a view similar to Fig. 6, illustrating unfolding of the collapsible chair.

Fig. 9 is a perspective view of a conventional collapsible chair.

Fig. 10 is a side view, partly sectioned, of a portion of the conventional collapsible chair in Fig. 9.

Fig. 11 is a side view of the conventional collapsible chair in a fully collapsed status.

Detailed Description of the Invention

Referring to Fig. 1, a collapsible chair in accordance with the present invention comprises a pair of front legs 11, a pair of rear legs 12, two armrests 15, a seat frame 13, and a backrest frame 14. Upper ends of the front legs 11 are pivotally connected to front ends of the armrests 15, respectively. Upper ends of the rear legs 12 are pivotally connected to intermediate portions of the armrests 15, respectively. Rear ends of the armrests 15 are pivotally connected to intermediate portions of two lateral sides of the backrest frame 14, respectively.

Rear ends of the seat frame 13 are pivotally connected to the lower ends of the lateral sides of the backrest frame 14 by pivotal devices 36. A collapsible chair is thus provided.

Still referring to Fig. 1 and further to Figs. 2 through 4, the collapsible chair further comprises a linking member 40 mounted on each rear leg 12. The linking member 40 comprises a first end 43 pivotally connected by a pin 41 to a lower end of an associated lateral side of the backrest frame 14. The liking member 40 further comprises a second end 44 pivotally connected by a pin 42 to an associated rear leg 12.

In this embodiment, the linking member 40 is substantially U-shaped and comprises two arms 45 respectively on two sides of the associated rear leg 12 and an intermediate section 47 that is between the arms 45 and that has a through-hole (not labeled), with the pin 41 pivotally extending through the through- hole of the intermediate section 47 and through the lower end of the associated lateral side of the backrest frame 14. Further, one of the linking members 40 comprises a stop face 46 adjacent to the first end 43 of the linking member 40. The stop face 46 extends from the intermediate section 47 and between the arms 45.

Still referring to Figs. 1 through 4, the collapsible chair in accordance with the present invention further comprises a positioning member 50 for retaining the collapsible chair in an extended status to provide a pinchpreventing effect. Referring to Figs. 3 and 4, the positioning member 50 is mounted on one of the rear legs 12 and slidable relative to the rear leg 12. In this embodiment, the positioning member 50 is mounted on a side of the rear leg 12 that faces away from the front leg 11. The positioning member 50 comprises a slot 55 in a wall 57 thereof and a rivet 60 is extended through the slot 55 of the positioning member 50 and a radial through-hole 12a in the rear leg 12. The rivet 60 includes a first end on which a head 61 is formed and a second end 62. The diameters of the head 61 and the second end 62 are greater than the radial through-hole 12a of the rear leg 12, preventing the rivet 60 from disengaging from the rear leg 12. Further, the diameter of the head 61 is greater than a width of the slot 55, and the head 61 is spaced from the wall 57 of the positioning member 50, allowing the positioning member 50 to slide along a longitudinal direction of the rear leg 12.

A spring-abutting member 63 is fixed on the rear leg 12 on which the positioning member 50 is mounted. In this embodiment, a rivet 64 is extended through the spring-abutting member 63 and a radial through-hole 1 2b in the rear leg 12 to fix the spring-abutting member 63 on the rear leg 12 at a level spaced from the wall 57 of the positioning member 50. Preferably, the radial through-hole 12b is below the above-mentioned radial through-hole 12a.

Preferably, the positioning member 50 comprises two lateral walls 58 between which the spring-abutting member 63 is located. Hence, the springabutting member 63 can be used as a guiding member for guiding the sliding movement of the positioning member 50 along a longitudinal direction of the rear leg 12.

The positioning member 50 further comprises a thumb-piece 54 for manual operation. Further, the positioning member 50 comprises a stop 51 on an end thereof. A spring 52 is mounted in the positioning member 50 and between the spring-abutting member 63 and an end wall 59 of the positioning member 50.

Referring to Figs. 3 and 4, when the collapsible chair is in an extended status, the positioning member 50 is biased upward by the spring 52 such that the stop 51 of the positioning member 50 is in contact with the stop face 46 of the associated linking member 40. Hence, collapse of the collapsible chair is prevented. This is because collapse of the collapsible chair requires forward movement of the rear legs 12, and which forward movement of one of the rear legs 12 is stopped by the stop face 46 of the linking member 40 due to provision of the stop 51 on the positioning member 50. A pinch-preventing effect is thus provided.

When collapsing the collapsible chair, the user grips the thumb-piece 54 and moves the positioning member 50 downward, as indicated by the arrow in Fig. 2. Referring to Fig. 5, the stop 51 of the positioning member 50 is disengaged from the stop 46 of the linking member 40, allowing subsequent collapse of the collapsible chair, as shown in Fig. 6.

Fig. 7 shows the collapsible chair in a fully collapsed status. As compared to the conventional collapsible chair comprising a sleeve 21 mounted around one of the rear legs 12, the overall height H of the fully collapsed chair in accordance with the present invention is smaller than that H' of the conventional collapsible chair (see Fig. 11). This is because the linking member 40 is not mounted to a side of the rear leg 12 that faces the front leg 11.

Referring to Fig. 8, when unfolding is required, the front legs 11 and the rear legs 12 are moved away from each other, and the stop 51 of the positioning member 50 slides across the stop face 46 of the associated linking member 40.

Preferably, the stop 51 of the positioning member 50 includes an inclined face 56 to allow smooth movement of the stop 51. After the stop 51 of the positioning member 50 moves across the stop face 46 of the associated linking member 40, the stop 51 of the positioning member 50 is biased by the spring 52 to a position shown in Fig. 3 preventing undesired collapse of the collapsible chair, as mentioned above.

Although a specific embodiment has been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.

Claims

Claims: 1. A collapsible chair comprising: a backrest frame including two

lateral sides; a seat frame including two lateral sides each having a rear end pivotally connected to a lower end of an associated one of the lateral sides of the backrest frame, two armrests each comprising a front end and a rear end, the rear end of each said armrest being pivotally connected to an intermediate portion of an associated one of the lateral sides of the backrest frame; two front legs each having an upper end pivotally connected to the front end of an associated one of the armrests; two rear legs each having an upper pivotally connected to an intermediate portion of an associated one of the armrests; two linking members respectively mounted on the rear legs, each said linking member comprising a first end pivotally connected to the lower end of an associated one of the lateral sides of the backrest frame and a second end pivotally coimected to an associated one of the rear legs; characterised in that: each said linking member is not located on a side of the associated rear leg that faces the associated front leg; one of the linking members comprises a stop face; a positioning niember is mounted on one of the rear legs and comprises a stop, the positioning member is slidable along a longitudinal direction of one of the rear legs; and a spring mounted on said one of the rear legs; wherein when the collapsible chair is in an extended status, the positioning member is biased by the spring to cause the stop to come into contact with the stop face of said one of the linking members, thereby preventing collapse of the collapsible chair; and wherein collapse of the collapsible chair is allowed when the positioning member is moved in a direction such that the stop of the positioning member is disengaged from the stop face of said one of the linking members.
2. The collapsible chair as claimed in claim 1 wherein each said linking member is substantially U-shaped and comprises two arms respectively on two sides of the associated rear leg and an intermediate section between the arms.
3. The collapsible chair as claimed in claim I wherein the intermediate section of each said linking member includes a through-hole, and wherein a pin is extended through the through-hole of the intermediate section and through the lower end of the associated lateral side of the backrest frame.
4. A collapsible chair substantially as hereinbefore described with reference to and as shown in Figures 1 to 8 of the accompanying drawings. ( ( (

4. The collapsible chair as claimed in claim 3 wherein the stop face of said one of the linking members extends from the intermediate section and between the arms.

5. The collapsible chair as claimed in claim 4 wherein: the positioning member is fixed by a rivet to said one of the rear legs; the positioning member comprises a wall with a slot; the rivet extends through the slot and said one of the rear legs; and the rivet comprises a head locate din the positioning member and spaced from the wall of the positioning member, allowing the positioning member to slide along the longitudinal direction of said one of the rear legs.

6. The collapsible chair as claimed in claim 5 further comprising a spring-abutting member fixed to said one of the rear legs, the spring being mounted between the spring-abutting member and an end wall of the positioning member.

7. The collapsible chair as claimed in claim 6 wherein the positioning member comprises two lateral walls between which the spring-abutting member is located.

8. The collapsible chair as claimed in claim I wherein the stop of the positioning member comprises an inclined face.

9. The collapsible chair as claimed in claim I wherein the positioning member further comprises a thumb-piece for manual operation.

10. The collapsible chair substantially as hereinbefore described with reference to and as shown in figures 1 through 8 of the accompanying drawings. i)

Amendments to the claims havébeen filed as follows: Claims: 1. A collapsible chair comprising: a backrest frame including two lateral sides; a seat frame including two lateral sides each having a rear end pivotally connected to a lower end of an associated one of the lateral sides of the backrest frame, two armrests each comprising a front end and a rear end, the rear end of each said armrest being pivotally connected to an intermediate portion of an associated one of the lateral sides of the backrest frame; two front legs each having an upper end pivotally connected to the front end of an associated one of the armrests; two rear legs each having an upper end pivotally connected to an intermediate portion of an associated one of the armrests; two linking members respectively mounted on the rear legs, each said linking member comprising a first end pivotally connected to the lower end of an associated one of the lateral sides of the backrest frame and a second end pivotally coimected to an associated one of the rear legs; each said linking member not being located on a side of the associated rear leg that faces the associated front leg; one of the linking members comprising a stop face; a positioning member being mounted on one of the rear legs and comprising a stop, the positioning member being slidable in a longitudinal direction relative to one of the rear legs; and a spring being mounted on said one of the rear legs; wherein, when the collapsible chair is in an extended status, the positioning member is biased by the spring to cause the stop to come into contact with the stop face of said one of the linking members, thereby preventing collapse of the collapsible chair; and wherein collapse of the collapsible chair is allowed when the positioning member is moved in a direction such that the stop of the positioning member is disengaged from the stop face of said one of the linking members; an intermediate section of each said linking member including a through-hole, a pin being extended through the through- hole of the intermediate section and through the lower end of the associated lateral side of the backrest frame; the stop face of said one of the linking members extending from the intermediate section and between the arms; characterized in that: the positioning member is fixed by a rivet to said one of the rear legs; the positioning member comprises a wall with a slot; the rivet extends through the slot and said one of the rear legs; and the rivet comprises a head located in the positioning member and spaced from the wall of the positioning member, allowing the positioning member to slide longitudinally relative to said one of the rear legs.

2. A collapsible chair as claimed in claim 1, further comprising a springabutting member fixed to said one of the rear legs, the spring being mounted between the spring-abutting member and an end wall of the positioning member.

3. A collapsible chair as claimed in claim 2, wherein the positioning member comprises two lateral walls between which the spring-abutting member is located.