WO1989000390A1

WO1989000390A1 - Folding chair

Info

Publication number: WO1989000390A1
Application number: PCT/DK1988/000119
Authority: WO
Inventors: Lawrence D. Minsker
Original assignee: Jungersen, Troels
Priority date: 1987-07-17
Filing date: 1988-07-13
Publication date: 1989-01-26
Also published as: DK373287D0; DK373287A; AU2121888A

Abstract

In a folding chair having upwardly open, U-shaped bows constituting front legs (10) and rear legs (11), and by pivot pins (16-19) being pivotably connected with a seat (12) and a back (13), the pivot axes are positioned in such relationship to each other that normally occurring force impacts do not cause the folded out chair to fold unintentionally. More precisely, the pivot axis (19) lies between the rear legs (11) and the back (13) in or somewhat in front of the plane comprising the pivot axes of the front legs (10).

Description

Folding chair

The invention relates to a folding chair of the kind stated in the introductory part of claim 1. The known folding chairs of this kind are not quite stable in the folded out position because the various pivot axes are positioned in such relationship to each other that certain load situations possibly arising in use may cause the chair to fold up with more or less annoying and at worst serious consequences for the user. This disadvantage has been sought eliminated by means of locking devices which, however, both make the chair more expensive and difficult to use.

It is the object of the invention to devise a folding chair of the kind described which is stable in the folded out position under all normally occurring conditions of use.

The object is achieved in that the folding chair is constructed as stated in the characterizing part of claim 1, the relative positioning of the pivot axes having the effect that a weight load on the seat under any circumstances will produce forces seeking to retain the chair in the folded out position.

A simple and expedient construction of the stop means is stated in claim 2.

In the following the invention is explained in more detail, reference being made to the drawing in which figs, 1, 2 and 3 are a sideview of an embodiment of the chair in folded out, partly folded out and folded position, respectively.

The chair has two front legs 10, two rear legs 11, a seat 12 and a back 13. The legs are made of flat steel tubes, e.g. having a width of 20 mm and a thickness of 10 mm. The two front legs 10 and a transverse bottom section 14 form an upwardly open, U-shaped, and so do the two rear legs 11, the bottom section of which is designated 15. The front legs 10 are by pivot pins 16, which e.g. may be tubular rivets, pivotably connected with the seat 12 at some distance from its rear edge and are furthermore by means of pivot pins 17 pivotably connected with the back 13 at a comparatively short distance from such edge thereof which in the folded out position of the chair constitutes the lower edge of the back. The rear legs 11 are by pivot pins 18 and 19 pivotably connected with the seat 12 near its rear edge and with the back 13 near its lower edge, respectively. The transverse section 15 of the rear legs is a section having the same size or being somewhat larger than double the leg thickness, shorter than the transverse section 14 of the front legs. On the inside of the front legs 10 and near their upper ends there are provided short protrusions 20 with semicircular crosssection, which in the folded out position of the chair shown in fig. 1 abut on the ends of the rear legs 11.

Initially, when folding the chair, the back is swung forwards as shown in fig. 2, the chair having been tilted onto either the front or the rear legs, or the entire chair having been lifted off the foundation, the folding subsequently being completed by pressing together the lower parts of the legs or by swinging down the seat about one of the pivot axes defined by the pivot pins 16 and 18. In the folded position shown in fig. 3 essentially the entire seat, most of the back and parts of the rear leg bow are positioned within the frame formed by the front leg bow. In order that the back and the seat may be positioned in the same plane, the back is preferably semicircular and the rear of the seat is provided with a recess having the form of a circle segment for receiving the upper part of the back.

From fig. 1 it is seen that a weight load on the seat of the folded out chair will produce a downwardly directed force in the front legs. If the front legs are lifted off the foundation, e.g. if the seated person tilts the chair backwards, this force will be transferred to the back via the pivot pin 17. As, however, the second pivot axis of the back through the pivot pins 19 is positioned on or very close to the line defined by the direction of force from the pivot pins 17, the force will be absorbed by the pivot pins 19 without producing any pivot momentum seeking to swing the back. Such pivot momentum, possibly entailing unintentional folding of the chair, is produced in the known folding chairs of the kind described where the pivot pins 19 are positioned offset behind the line of the direction of force through the pivot pins 17.

The details of the chair shown and described can be changed in various ways within the scope of the invention. E.g. the stop means 20 on the front legs could optionally be relaced by some kind of protrusion on the rear legs for abutment on the front legs in completely folded out position.

Claims

P a t e n t C l a i m s

1. A folding chair consisting of a seat, a back and two upwardly open, ϋ-shaped bows constituting front legs and rear legs, respectively, and where the rear legs are pivotably connected partly at their upper ends with the back at is lower edge, partly at some distance from the ends with the seat at its rear edge, and where the front legs are pivotably connected partly at their upper ends with the seat at some distance from its lower edge, partly at some distance from the ends with the seat at some distance from its rear edge, c h a r a c t e r ¬ i z e in that the front and the rear legs have cooperating stop means which when the chair is completely folded out abut on each other, and that the pivot axis between the rear legs and the back in this position lies essentially in or in front of the plane comprising the pivot axes of the front legs.

2. A folding chair according to claim 1, c h a r a c t e r i z e d in that the stop means are constituted by inwardly directed protrusions on the front legs and on the ends of the rear legs.