GB2302562A

GB2302562A - A pivot mechanism

Info

Publication number: GB2302562A
Application number: GB9613083A
Authority: GB
Inventors: Sheldon King
Original assignee: Sebel Furniture Ltd
Current assignee: Sebel Furniture Ltd
Priority date: 1995-06-23
Filing date: 1996-06-21
Publication date: 1997-01-22
Also published as: KR970000126A; GB9613083D0; JPH09140501A; AUPN376695A0; TW300847B; ZA965314B

Abstract

In a snap engageable pivot mechanism (9) for stadium seats the fixed part of the seat carries a circular aperture (18) in a resiliently displaceable cantilever arm which includes a lead-in ramp (20). The pivotable seat (7) carries a boss 25 having an inclined upper surface. Engagement of the inclined surface and lead-in ramp (20) displaces the arm to permit the aperture (18) to rotatably engage the boss (25) which thereby forms a stub axle. A release hole adjacent the boss permits insertion of an instrument to effect disengagement by displacing the cantilever arm. Surfaces (13, 14) cooperate respectively with surfaces (29, 28) to limit pivoting.

Description

A PIVOT MECHANISM The present invention relates to a pivot mechanism, and in particular, to a pivot mechanism suitable for seating.

It is well known that some types of seating, particularly seating used in stadia and auditoria. are provided with a rigid backrest and a pivoted seat which is able to be tilted between a substantially horizontal use position and a substantially vertical access position. There are many various types of pivot mechanism which allow such tilting seats to be pivoted.

However, in order to produce a low cost stadium seat it is desirable that both the seat and the backrest be able to be produced by a low cost method such as injection moulding. Furthermore, if the pivot mechanism can also be injection moulded into the parts of the seat arrangement. then this also substantially reduces the cost of the components of the seating arrangement.

Another substantial cost is the cost of assembling or erecting the seating arrangement in their final position. Normally such a seating arrangement is fabricated in a factory some distance from its intended final destination. The parts are shipped to that destination in a IcnocE;4own condition. With stadium seats, it is normally necessary for the fixed portion of the seat, including the seat pivot supports, to be positioned in their final location, and then the individual seats are installed. This installation requires not only that the sear pivots as desired. but also that the seats cannot be disengaged from the pivot mechanism and thereby stolen or otherwise vandalised by members of the audience.

It is the object of the present invention to provide a snap engageable pivot mechanism which enables the seats of such stadium seating to be quickly and easily installed.

In accordance with one aspect of the present invention there is disclosed a snap engageable pivot mechanism comprising a substantially cylindrical boss having a top face with a ramp surface inclined relative to the longirudinal axis of said cylindrical boss and forming a stub axle. said boss being carried bv a first part and a circular aperture in a cantilever arm resiliently displaceable in a direction away from said boss and having a lead-in ramp on the free end of said ann and facing said boss. said arm being carried by a second part, and said first and second parts being engageable by sliding said boss ramp surface over said lead in ramp to resiliently move said ann free end away from said boss until said boss is engaged with said aperture, said boss being rotatable relative to said aperture to allow relative pivoting motion between said first and second parts.

Preferably, the first and second parts are each provided with a pair of stops to limit the arc through which said first and second parts pivot with respect to each other.

In accordance with a second aspect of the present invention there is disclosed a method of installation of the tilting seats of a stadium seating arrangement.

An embodiment of the present invention will now be described 'itl1 reference to the drawings in which: Fig. 1 is a perspective view of a row of stadium seats in their final assembled state: Fig. 2 is a perspective view of one of the seats of Fig. 1 showing the seat in its substantially horizontal use position; Fig. 3 is a view similar to Fig. 2, but showing the seat in its raised access position; Fig. 4 is a perspective view of the pivot aperture carried by the yoke which supports the bacle rest of the seat; Fig. 5 is a plan view of the pivot aperture of Fig. 4; Fig. 6 is a transverse cross-sectional view through the pivot aperture along the line VI-VI of Fig. 5; Fig. 7 is a perspective view of the stub axle mechanism carried by the seat; Fig. 8 is a plan view of the stub axle mechanism of Fig. 7:: Fig. 9 is a transverse cross-sectional view along the line IX-IX of Fig. 8; Fig. 10 is a composite view juxtaposing the cross-sectional views of Figs. 6 and 9 and showing the first step in the assembly procedure: Fig. 11 is a view similar to Fig. 10 but illustrating an intermediate stage in rhe assembly procedure; Fig. 12 is a view similar to Fig. 11 but showing the final step in the assembly procedure; Fig. 13 is a schematic plan view illustrating the assembly procedure; and Figs. 14 and 15 are views similar to Fig. 13 but illustrating the assembled pivot mechanism and illustrating the extremes of pivoting motion.

As seen in Fig. 1 a row 1 of stadium seats 2 is formed by mounting a number of the stadium seats 2 along a rail 3. As seen in Fig. 2 each of the stadium seats 2 talces the form of a backrest 6 and a seat 7. As seen in Fig. 3, the seat 7 is pivotal form a substantially horizontal use position illustrated in Fig. 2. to a substantially vertical access position illustrated in Fig. 3. The backrest 6 is supported by a two armed yoke 8 and each arm of the yoke 8 carries a pivot mechanism 9 (only one of which is visible in Figs. 2 and 3).

Turning now to Fig. 4, the interior of the yoke 8 Is illustrated to reveal that pan of the pivot mechanism 9 carried by the yoke 8. This takes the form of generally cylindrical upstand 11 having a triangular portion 12 with two flats 13,14. Formed on the outer face of the upstand 11 is a cantilever arm 16 which is separated from the remainder of the upstand 11 by means of t'vo slots 17. The cantilever arm 16 carries a circular aperture 18 which is to form one of the bearing surfaces. The free end 19 of the cantilever arm 16 is provided with a lead-in ramp 20.It will be appreciated from Figs. 44 that the entire structure is able to be injection moulded from plastics material and the slots 17 ensure that the cantilever arm 16 is resiliently displaceable In addition, the upstand 11 is provided with a peripheral lip 21 which is substantially circular and concentric with the aperture 18.

Turning now to Fig. 7, here the stub axle portion 24 of the pivot mechanism 9 which is carried by the sear 7 is illustrated. The stub axle portion 24 takes tht: form of a substantially cylindrical boss 25 having an inclined upper face 26 (best illustrated in cross-section in Fig 9). In addition, surrounding the boss 25 is a circular recess 27 the diameter of which is substantially equal to the of the peripheral lip 21 The seat 7 is also provided with two stops 28.29 and a release hole 30.

As best seen in Fig. 10. it will be appreciated that prior to assembly the seat 7 is able to be moved relative to the yoke 8 so as to orientate the inclined upper face 26 of the boss 25 opposite to the lead-in ramp 20 of the cantilever ann 16. If the seat 7 is now pushed towards the yoke 8, the face 26 and lead-in ramp 20 engage thereby resiliently displacing the cantilever arm 16 as illustrated in Fig. 11 so as to move same away from the boss 25. As a result, the boss 25 slides over the lead-in ramp 26 and is able to be located within the aperture 18. This is the situation illustrated in Fig. 12 and the recess 27 has also mated with the peripheral lip 21. The above action illustrated in Figs. 10-12 constitures a quick and easy assembly step.

The assembly procedure is also schematically illustrated in Fig. 13 and the position once the assembly has taken place is illustrated in Figs. 14 and 15. In Fig. 14 the seat 7 has been pivoted so as to bring the flat 13 into engagement with the stop 29.

This limits the downward movement of the seat 7 and the engagement of these two portions distributes the forces generated by the person sitting onto the seat, into the yoke 8 and thus into the backrest 6 and rail 3.

The position illustrated in Fig. 15 is where the seat 7 has been rotated into the substantially vertical access position. Here the flat 14 is brought into engagement with the stop 28 to limit the pivoting motion in the seat raising direction. If desired, the stop 28 and/or the face 14 can be provided with a resiliently compressible portion such as rubber block (not illustrated) which provides a cushioning effect rather than an abrupt stop.

If it becomes necessary to disassemble the seat and backrest, a thin pin or needle is pushed through the release hole 30 to displace the free end 19 of the cantilever arm 16. If this is done simultaneously for both pivots 9, the seat 7 can be removed from the remainder of the seating arrangement 2.

The foregoing describes only one embodiment of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.

Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other disclosed and/or illustrated features.

The appended abstract as filed herewith in included in the specification by reference.

Claims

1. A snap engageable pivot mechanism comprising a substantially cylindrical boss having a top face with a ramp surface inclined relative to the longitudinai axis of said cylindrical boss and fonning a stub axle, said boss being carried by a first part, and a circular aperture in a cantilever arm resiliently displaceable in a direction away from said boss and having a lead-in ramp on the free end of said arm and facing said boss, said ann being carried by a second part, and said first and second parts being engageable by sliding said boss ramp surface over said lead in ramp to rcsiliently move said arm free end away from said boss until said boss is engaged with said aperture, said boss being rotatable relative to said aperture to allow relative pivoting motion between said first and second pans.

2. A mechanism as claimed in claim 1 wherein an opening in said first part adjacent said boss is aligned with said free end of said cantilever arm when said relative pivoting motion between said first and second parts aligns said ramp surface and lead-in ramp, whereby said free end is able to be deformed to clear said boss and release the engagement between said first and second parts.

3. A mechanism as claimed in ua 1 or 2 wherein said first and second parts are each provided with a pair of stops to limit the arc through which said first and second parts pivot with respect to each other.

4. A mechanism as claimed in any one of clatas 1 to 3 and comprising the pivot nX of a stadiun chair having a backrest and a pivotable seat.

5. A mechanism as claimed in claim 4 wherein said first part comprises the pivotable seat and said second part is fixed relative to said backrest.

6. A mechanism as claimed in claim 5 wherein the first and second parts are each integrally moulded from plastics material.

7. A mechanism as hereinbefore described with reference to the accompanying description, drawings or description and drawings.

8. A method of installation of a pivoting seat in a stadium chair in which said chair is provided with a pair of said cantilever arms arranged in parallel configuration on opposite sides of the space to be occupied by said seat, and said seat is provided with a pair of said bosses with aligned ramp surfaces, said method comprising the steps of: (1) aligning said ramp surfaces and cantilever arms by movement of said seat after the remainder of said chair has been installed, (2) pushing said seat towards said chair to inter-engage said ramp surfaces and lead-in lamps to thereby resiliently displace said cantilever arms, and (3) continuing said pushing motion until each said boss is engaged with the corresponding aperture in the corresponding cantilever arm.

9. A method as hereinbefore described with reference to the accompanying description, drawings, or description and drawings.