EP1127516A1

EP1127516A1 - Folding chair

Info

Publication number: EP1127516A1
Application number: EP00306998A
Authority: EP
Inventors: Shing Chi Tsang; Sing Tak Tsang; Shing Yip Tsang
Original assignee: B T Furnishing Sdn Bhd
Current assignee: B T Furnishing Sdn Bhd
Priority date: 2000-02-28
Filing date: 2000-08-16
Publication date: 2001-08-29
Anticipated expiration: 2020-08-16
Also published as: EP1127516B1; AU3632401A; ATE280524T1; WO2001064077A3; WO2001064077A2; DE60015290T2; DE60015290D1

Abstract

A folding chair includes a locking mechanism (10, 12, 15) for improved user safety. A locking bar (10) is mounted for limited movement on the underside of a seat panel (3). In the operation of opening the chair for use, the locking bar (10) automatically assumes a locking position in which it is located in a notch (15) formed in one leg frame (5). In order to close the chair, the user must first deliberately and manually dislodge the locking bar (10) from the notch (15). In another embodiment, a pair of folding leg frames (21, 22) are coupled together by a slotted sliding bar (27). A pin (29) which pivotally connects the seat panel (23) to one of the leg frames rides within the slot (28). The slot includes an angled locking portion (32) at one end which traps the pin (29) and thereby locks the leg frames in the open position. The lock is released by manually lifting the sliding bar so that the pin (29) re-enters the sliding portion (31) of the slot (28).

Description

This invention relates to a folding chair of the type comprising a pair of leg frames that are hinged together so that the chair may be folded substantially flat when not in use.
In one chair of this general kind, a seat panel has one end hinged to one of the frames with the opposite end supported by the other frame when the chair is open for use. In another chair of this general kind, a seat panel and back support are hinged together to form a seat assembly that may be folded substantially flat, and the seat assembly is supported by the pair of leg frames.
By their very nature, chairs of this type are inevitably prone to collapse during use. This can cause serious bodily injury. Additionally, the chair often collapses when it is lifted to be moved to another location. This is naturally inconvenient. Therefore, the aim of the invention is to realise a folding chair offering improved safety and/or convenience to the user.
According to a first aspect of the invention, a folding chair comprises a first frame that forms the rear legs of the chair and a second frame that forms the front legs of the chair, the first and second frames being pivotally connected so as to enable the chair to be folded substantially flat when not in use, and further comprises a seat panel that has one end pivotally connected to one of the frames and an opposite end engagable with the other of the frames whereby said other frame supports said opposite end of the seat panel when the chair is open for use. The chair is characterized in that a locking member is mounted on one of said other frame and said opposite end of the seat panel for limited movement relative thereto, and the other of said other frame and said opposite end of the seat panel includes a locking formation for receiving the locking member to lock the chair in the open condition, the limited movement of the locking member enabling the locking member to assume a locking position in which the locking member is located within the locking formation, and a release position in which the locking member is located outside the locking formation. The arrangement is such that the locking member automatically assumes the locking position in the action of opening the chair whereas the locking member must be manually moved into the release position in order to unlock and fold the chair.
The above features ensure that the chair is locked automatically upon opening while, in order to collapse the chair, the user must first manually operate the locking member to unlock the chair. As a. result, the folding chair of this first aspect of the invention incorporates a highly effective and safe locking mechanism whose operation is not dependent on the user remembering to lock the chair and which has a low probability of being accidentally released while the chair is in use.
In a preferred embodiment, the locking member comprises a bar extending laterally across the width of the chair, and the locking formation comprises a groove or notch adapted to locate an edge of the bar. In order to achieve the required limited movement of the locking member, the opposite ends of the bar may be loosely trapped in respective recesses of a shape which permits movement of the bar between the locking position and the release position. These recesses may have a substantially triangular shape whereby the bar rests against one inclined side of the triangle in the locking position.
The locking member is preferably biased into the locking position. The bias may arise under the action of gravity on the locking member or under the action of resilient means such as at least one spring element, or both. In the action of opening the chair for use, the locking member may be temporarily and automatically displaced from its bias position into the release position before being returned, by virtue of the biasing action, into the locking position in which the locking member engages the locking formation.
In one design, the seat panel is hinged to the second frame that forms the front legs of the chair. In this design, the locking member is mounted on the seat panel and the locking formation is formed at the end of the first frame that forms the rear legs of the chair and supports the front edge of the seat panel. In this design, the first frame may engage the seat panel by means of pins that extend outwardly from the frame and slide within respective grooves formed at each side of the seat panel.
Alternatively, the seat panel may be hinged to the first frame that forms the rear legs of the chair. In this case, the locking member is mounted on the second frame that forms the front legs of the chair and the locking formation is formed at the rear edge of the 0 seat panel. The rear end of the seat panel is supported by the second frame when the chair is open for use.
According to a second aspect of the invention, a folding chair comprises a pair of leg frames that are pivotally connected together so as to enable the chair to be folded substantially flat when not in use, and further comprises a seat panel supported by said pair of leg frames, characterized in that the opening and closing of the pair of leg frames is governed by a sliding bar that connects the two leg frames, the sliding bar having one end pivotally coupled to a first said leg frame and including an elongate slot, a pin mounted on a second said leg frame being arranged to ride within said elongate slot, and in that said elongate slot includes an angled locking portion at an end of the slot, the arrangement being such that said pin automatically enters the locking portion of the slot in the action of opening the chair whereas the pin must be manually released from the locking portion, by manipulating the sliding bar, in order to unlock and fold the leg frames.
The above features ensure that the chair legs are automatically locked upon opening while, in order to collapse the chair, the user must first manually operate the or each sliding bar to unlock the legs. As a result, the folding chair of this second aspect of the invention incorporates a highly effective and safe locking mechanism whose operation is not dependent on the user remembering to lock the chair and which has a low probability of being accidentally released while the chair is in use.
In a preferred embodiment, the locking portion of the sliding bar slot extends generally upwardly when the chair is open for use, so that the pin enters the locking portion as the sliding bar drops under the action of gravity. The locking portion of the slot may, for example, extend at approximately 90° to the main portion of the slot. These features contribute advantageously to the automatic locking operation.
In a chair according to this second aspect of the invention, the seat panel may be pivotally connected to the second leg frame by means of said pin. A back support may be hinged to the seat panel to form a collapsible seat assembly. The hinge connection may be of such a type that the angle between the seat panel and the back support is adjustable to a plurality of settings that provide different degrees of repose. The chair may thus be a multi-position, for example 5-position, folding chair.
The sliding bar is preferably provided on only one side of the chair in order to simplify the unlocking operation.
According to both aspects of the invention, the folding chair does not collapse when lifted up to be moved to a new location. This adds to the chair's convenience in everyday use.
The invention is illustrated, but not limited, by the following description of preferred embodiments, given by way of example only, with reference to the accompanying drawings, in which:
Figs 1 to 8 relate to a folding chair according to a first embodiment of the invention, wherein:
Fig. 1 is a side view of the folding chair in its open state,
Fig. 2 is a side view of the chair in its folded state,
Fig. 3 shows a rear leg frame of the chair,
Fig. 4 is an end view of the seat panel,
Fig. 5 is an internal side view of the seat panel,
Fig. 6 is a view of the locking mechanism with the locking bar in its locking position,
Fig. 7 is a view of the locking mechanism with the locking bar in its release position, and
Fig. 8 shows a modification of the locking mechanism; and

Fig. 9 is a side view of the folding chair in its open state, and
Fig. 10 shows detail of a sliding bar adapted for use in locking the leg frames.

Referring firstly to Figs. 1 to 7, a first embodiment of the folding chair will be described. Fig. 1 shows the chair in its open condition and Fig. 2 in its closed or folded state. The chair comprises a pair of leg frames 1, 2 which are coupled together by means of a pivot connection, such as a hinge, at a point remote from the ends of the frames. The first leg frame 1 forms the rear legs of the chair and the second frame 2 forms the forward legs of the chair. In this embodiment, the second frame 2 also extends upwardly to form the back support of the chair. The back of the seat panel 3 is pivotally connected by means of a hinge to the second frame 2. The front of the seat panel 3 is supported by the upper end of the first frame 1 when the chair is open for use.
Figs. 3 to 5 illustrate how the rear leg frame 1 is coupled to the seat panel. As shown in Fig. 3, the frame 1 comprises a pair of mutually parallel side members 5 that form the rearwardly extending legs. The side members 5 are connected together by a pair of cross bars 6. The upper ends of the side members 5 (as viewed in Fig. 1) include respective laterally outwardly extending pins 7, each of which may take the form of a screw or cylindrical stud or the like. As seen in Figs. 4 and 5 the seat panel 3 comprises a seating board 8 and a pair of side timbers 9. The inward faces of the side timbers 9 include a groove 11 that extends substantially the length of the side timber 9.
The pins 7'of the leg frame 1 ride in the respective grooves 11 of the seat panel as the chair is opened and closed. When the chair is open for use, the pins 7 reside in the leftmost ends of the grooves 11, as viewed in Fig. 5. On the other hand, when the chair is fully folded, the pins 7 are located at the rightmost ends of the grooves 11, as viewed in Fig. 5. The chair is closed by lifting the front edge of the seat panel 3 upwardly and moving the same in the direction of the arrow 4 shown in Fig. 1. As the seat panel 3 moves towards the back support portion of the frame 2, the shorter frame 1 rides in the grooves 11 of the seat panel as the frames 1 and 2 close together in a scissors-like action.
The locking mechanism in this embodiment comprises a locking bar 10 which is mounted on the underside of the seat panel towards the front edge thereof. In the locked condition, the locking bar 10 is located in notches 15 formed in the upper edges of the side members 5 of the shorter leg frame 1. The locking bar 10 extends laterally across the width of the seat panel. Its ends are located loosely in substantially triangular-shaped recesses 12 formed in the side members 9 of the seat panel. The locking bar is biased into the locking position shown in Figs. 5 and 6 under the action of gravity, as represented by the arrow 13 in Fig. 6. In this state, the locking bar rests on the inclined edges of the triangular recesses 12.
In the operation of opening the chair, the leg frame members 5 slide along the grooves 11 in the seat panel, moving in the left direction as viewed in Figs. 5 to 7. As the ends of the leg frame members 5 approach the final position at the leftmost ends of the grooves 11, the locking bar 10 is temporarily moved upwardly being dislodged by the upper ends of the frame members 5. Immediately thereafter, the locking bar 10 drops down to the locking position in which the lower edge of the locking bar is located within the triangular notch 15 of each frame member 5. The chair is now in the locked condition shown in Fig. 6. The leg frame 1 is prevented from moving upwardly by the location of the pins 7 at the ends of the grooves 11 and to the left by the stop block 17.
Movement of the leg frame members 5 in the rightward direction (as seen in the drawings) in an attempt to close the chair is prevented by the locking bar being located in the notches 15. The chair is thus locked automatically in the course of opening the chair for use.
In order to close the chair, the user must temporarily dislodge the locking bar 10 from the notches 15 by moving the locking bar 10 into the release position, as shown by the arrow 14 in Fig. 7. The leg frame members 5 are then free to travel along the groove 11 to close the chair. Once the upper ends of the frame members 5 have passed the locking bar 10, the latter will drop back under the action of gravity to the bias position shown in Fig. 5.
Fig 8 shows a modification of the locking mechanism in which resilient means are employed to bias the locking bar into the locking position. For this purpose, an angled plate 18 formed of spring steel sheet is mounted at each end of the locking bar 10. The plate 18 may be secured to the locking bar by means of one or more screws. Each plate 18 is arranged as shown whereby the bar 10 is moved to the release position against the spring action and returns to the biased position upon release.
Referring now to Figs. 9 and 10, a second embodiment of the folding chair of the invention will be described. Fig. 9 is a side view of the chair in its open condition while Fig. 10 shows detail of the sliding bar that forms a key part of its locking mechanism.
As seen in Fig. 9, the chair includes a pair of leg frames consisting of a front leg frame 21 and a rear leg frame 22. The two leg frames 21, 22 are hinged together at their upper ends. The chair further includes a seat assembly consisting of a seat panel 23, a back support 25 and a pair of arm rests 26. The seat panel 23 and back support 25 are connected together at the rear of the chair by means of hinges on either side. When the chair is open for use, the seat assembly is supported by the leg frames. The seat panel is coupled to the legs of the frame 21 towards the front of the seat panel by means of respective pins 29 which pivotally connect each side of the seat panel to the adjacent front leg. The back support 25 is coupled to the pair of leg frames by the arm rests 26. In this embodiment, the pivot connections between the arm rests and the back support and the couplings between the arm rests and the leg frames permit limited movement of the back support 25 relative to the seat panel 23 when the chair is in its open state. This enables the inclination of the back support 25 to be adjusted to any of a number of preset positions corresponding to different degrees of repose. However, this feature is not essential and the back support may alternatively have a single, fixed angle relative to the seat panel when the chair is open for use.
The respective connections between the seat panel and back support, back support and arm rests, and arm rests and leg frames are already known in the art and do not form any part of the invention. Therefore, these connections will not be described in further detail herein. When the chair is in its folded state, the leg frames 21, 22 are brought together, as shown by the arrows 30, so as to be substantially flat. Similarly, the seat panel and back support are brought together, as shown by the arrows 24, so as to be substantially flat.
In accordance with this embodiment, the opening and closing of the chair is governed by a sliding bar 27 which links the front and rear leg frames. In this embodiment, a single sliding bar 27 is provided on the right hand side of the chair. It will be obvious that the sliding bar could alternatively be provided on the left hand side of the chair or, less preferably, on both sides. One end of the bar 27 is pivotally connected to the rear leg 22 so that the bar may rotate about the pivot connection. As best seen in Fig. 10, the bar includes an elongate longitudinal slot 28 which extends inwardly a predetermined distance from the other end of the bar. The pin 29 which couples the seat panel 23 to the front leg 21 rides within the slot 28. The inner end 33 and the outer end 34 of the slot 28 determine the limits of the travel by the pin 29.
As seen in Fig. 10, the outer end 34 of the slot includes a locking portion 32 which, in this embodiment, extends at approximately 90° to the main portion 31 of the slot. When the chair is folded, the pin 29 rests at the inner end 33 of the slot. As the chair is opened for use, the pin travels outwardly towards the end 34 of the slot. Upon the pin 29 reaching the outer end 34 of the slot 28, the sliding bar 27 drops down under the action of gravity since, at this time, the locking portion 32 is disposed generally vertically. In this way, at the end of its travel, the pin 29 automatically enters the locking portion 32 and comes to a rest at the end 35 of the slot 28. in this condition, the chair is locked due to the pin 29 being trapped within the locking portion 32 of the slot.
It will be noted that, in this condition, the chair cannot be collapsed simply by moving the legs. Additionally, lifting the chair to move it to another position by grabbing hold of the seat panel or arm rests does not result in the chair collapsing. In order to close the chair, the pin 29 must be released from the locking portion 32 of the slot by lifting up the outer or forward end of the sliding bar 27. At this time, the pin 29 reaches the end 34 of the linear portion 31 of the slot and may therefore slide to the other end 33 of the slot.
The invention may be embodied in numerous other ways without departing from the scope thereof. As an alternative to the described mounting arrangement for the locking bar of the first embodiment, the upper edge of the bar may be pivotally connected to the leg frame or seat panel. The movement of the locking bar between the locking and release positions may then be controlled by means of suitably positioned stopping members. In the described first embodiment, the second frame extends upwardly to form a back support for the chair. However, the principles of the invention are applicable equally to a chair in the form of a stool which has no back support. In regard to the second embodiment, the seat assembly may comprise a seat panel without any back support. A seat assembly that includes a back support may have a single opening angle or may be of the multi-position type. The sliding bar may be provided respectively on both sides of the chair, although such a design is less convenient in use. A chair in accordance with either aspect of the invention may also incorporate arm rests that are hinged to one or more of the leg frames, seat panel and/or back support in a manner that is known per se in the art.

Claims

A folding chair comprising a first frame (1) that forms the rear legs of the chair and a second frame (2) that forms the front legs of the chair, the first and second frames (1, 2) being pivotally connected so as to enable the chair to be folded substantially flat when not in use, and further comprising a seat panel (3) that has one end pivotally connected to one of said frames and an opposite end engagable with the other of said frames whereby said other frame supports said opposite end of the seat panel when the chair is open for use, characterized in that a locking member (10) is mounted on one of said other frame and said opposite end of the seat panel for limited movement relative thereto, and the other of said other frame and said opposite end of the seat panel includes a locking formation (15) for receiving said locking member (10) to lock the chair in the open condition, said limited movement of the locking member enabling the locking member to assume a locking position in which the locking member (10) is located within the locking formation (15), and a release position in which the locking member is located outside the locking formation, the arrangement being such that the locking member (10) automatically assumes the locking position in the action of opening the chair whereas the locking member must be manually moved into the release position in order to unlock and fold the chair.
A folding chair according to claim 1, wherein said locking member comprises a bar (10) extending laterally across the width of the chair, and said locking formation comprises a groove or notch (15) adapted to locate an edge of said bar.
A folding chair according to claim 2, wherein the opposite ends of said bar (10) are loosely trapped in respective recesses (12) of a shape which permits movement of the bar between said locking position and said release position.
A folding chair according to claim 3, wherein each of said recesses (12) has a substantially triangular shape and said bar (10) lies adjacent one side of the triangle in said locking position.
A folding chair according to any one of claims 1 to 4, wherein said locking member (10) is biased into said locking position under the action of gravity.
A folding ohair according to any one of claims 1 to 4, wherein said locking member (10) is biased into said locking position under the action of resilient means (18).
A folding chair according to any one of claims 1 to 6, wherein said other frame (1) engages said seat panel (3) by means of pins (7) that extend laterally outwardly from the frame (1) and slide within respective grooves (11) formed at each side (9) of the seat panel.
A folding chair according to claim 7, wherein said first frame (1) constitutes said other frame.
A folding chair comprising a pair of leg frames (21,22) that are pivotally connected together so as to enable the chair to be folded substantially flat when not in use, and further comprising a seat panel (23) supported by said pair of leg frames, characterized in that the opening and closing of the pair of leg frames (21, 22) is governed by a sliding bar (27) that connects the two leg frames, the sliding bar (27) having one end pivotally coupled to a first said leg frame (22) and including an elongate slot (28), a pin (29) mounted on a second said leg frame (21) being arranged to ride within said elongate slot, and in that said elongate slot (28) includes an angled locking portion (32) at an end of the slot, the arrangement being such that said pin (29) automatically enters the locking portion (32) of the slot in the action of opening the chair whereas the pin must be manually released from the locking portion, by manipulating the sliding bar (27), in order to unlock and fold the leg frames.
A folding chair according to claim 9, wherein the locking portion (32) extends generally upwardly when the chair is open for use, so that said pin (29) enters the locking portion as the sliding bar (27) drops under the action of gravity.
A folding chair according to claim 9 or claim 10, wherein said seat panel (23) is pivotally connected to said second leg frame (21) by means of said pin (29).
A folding chair according to any one of claims 9 to 11, wherein a back support (25) is hinged to the rear of the seat panel (23).