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Publication numberUS3601444 A
Publication typeGrant
Publication dateAug 24, 1971
Filing dateNov 25, 1969
Priority dateSep 23, 1969
Publication numberUS 3601444 A, US 3601444A, US-A-3601444, US3601444 A, US3601444A
InventorsDoerner Joseph T
Original AssigneeDoerner Products Co Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Chair control with support for the torsion spring
US 3601444 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

I United States Patent [1 13,601,444

[72] Inventor Joseph T. Doerner [56] References Cited 7 wfltsrlw Ontario, Canada UNITED STATES PATENTS {5;} gm 12 1969 2,202,630 10/1970 Hauber 5/309 ux Patented g 1971 3,339,973 9/1967 Doemer 297/300 [73] Assignee Doerner Products Co. Limited Primary ExaminerJames C. Mitchell Waterloo, Ontario, Canada Attorney-George H. Riches 32] Priority Sept. 23, 1969 [33] Canada [31 062,731

ABSTRACT: A chair control for tilting chairs and posture chairs having a coiled torsion spring oriented in a horizontal [54] WITH SUPPORT FOR THE plane with its axis parallel to the pivots on which the control 2 Claim 3 D F tilts. The chair control has two frames which are pivotally conrawmg nected to permit relative pivotal movement, one of the frame [52] U.S. Cl 297/300, members being mountable on the top end of the chair post 248/383 which is carried by the chair base. The torsion spring is sup- [51] Int. Cl A47c 3/00 ported by a fixed frame of the chair control so that it is fully [50] Field of Search 5/309; supported thereby both when at rest and when subjected to torsional stresses induced by a person sitting in the chair when such person leans backin the chair.

PATENTEU AUB24 l9?! Invenror fi p T- Doerner AHorney CHAIR CONTROL WITI-I SUPPORT FOR THE TORSION SPRING I BACKGROUND THE INVENTION The present invention is an improvement on the chair control disclosed in my prior Canadian Pat. No. 771,456 dated Nov. 14, 1967 and its United States counterpart, U.S. Pat. No. 3,339,973 dated Sept. 5, I967. In that structure the torsion spring was supported on a nylon bushing carried on the pivot pin connecting the cooperating pivot elements of the chair control. The pivot pin is thus subjected to considerable strain which, in time, distorts and fatigues the pin.

I have found that the aforesaid-problem can be solved by supporting the spring on a pad, such as nylon, the pad, in turn, being supported on one of the frame members of the chair control, preferably the fixed frame member which is mounted on the chair spindle.

DESCRIPTION OF THE INVENTION The invention will be described as applied to a secretarial chair but it is to be understood that this is by way of illustration only since it is obvious that it can be used with other kinds of chairs.

For an understanding of the present invention and its advantages, reference is to be had to the following description taken in conjunction with the accompanying drawings. in which:

FIG. 1 is a perspective view of a tilter chair employing the chair control of the present invention;

FIG. 2 is a side elevation in cross section through the center of the chair running from front to back thereof to show details of the construction; and

FIG. 3 is a cross-sectional view taken on the same line as FIG. 2 with the back tilted.

FIGS. 1-3 show the present invention as applied to what is commonly known as a posture or secretarial chair.

The posture or secretarial chair incorporates a modified chair control A designed to provide yieldable, backward-tilting support for a tiltable chair back pivotally connected to the chair seat 11 through the medium of the chair control A, the seat in turn being fastened to the control as herein described.

The chair control includes a first frame structure 14 which includes a plate 16 apertured to receive the spigotted end of the spindle l2 and a bushing 13 rigidly attached to the plate l6 with the apertures'in sidewalls 15. A hinge pin 21 is mounted through the said apertures to connect the first and second frames for relative-pivotal movement.

Tilt-resisting spring-biasing means 22 are provided for the chair control to urge the chair back 10 to a normal or first position as illustrated in FIG. 2 and resist movement to the second position as shown in FIG. 3.

The aforementioned spring-biasing means 22 comprise a torsion spring 23 including pair of oppositely wound coils 24, 25 coiled about the hinge pin 21 and mounted between the spaced-apart sidewalls 15. The torsion spring 22 also includes oppositely extending ends 26, 27 of each of said coils 24, 25

' and a first end 28, 29 of each of said coils 24, 25 is joined by a and apertured to receive the shank of the spindle 12. The first connecting portion 30. The connecting portion 30 is connected to the first frame structure 14 by connecting means comprising a threaded rod 31 which is hooked at one end over the connecting portion 30 and which extends at its other end through the plate 16 and is threaded into a manually operable tension-adjustin2g nut 32 for the sprin -biasing means 22, said ad usting nut 3 being easily accessib e on the outside of the first frame member 14.

The hinge'pin passes centrally through the coiled tension spring as shown. The spring 23 is on a support pad 33 which extends under the spring between the spaced-apart sidewalls 15. The pad 33 is preferably made of nylon and has its upper surface concaved to the curvature of the coils. The concaved surface forms a recess into which the coiled spring seats, the spring being thereby restrained against eccentric displacement when the spring is torsionally twisted. The pad 33, in turn, is supported, on the base portion 34 of the frame 16 in close proximity to the bushing 13. The forces created by the torsion spring are thus carried on parts adapted to carry heavy loads.

What I claim is:

l. A chair control having:

a. a first nontiltable frame mountable on a chair base;

b. a second tiltable frame member;

c. a helical torsion spring operatively connected to the frame members to resist relative movement of the frame members in one direction;

(I. a hinge pin pivotally connecting the frame members together for relative pivotal movement, said pin extending axially through the torsion spring; and

. a spring support pad mounted on the first frame underneath the torsion spring, said pad having its upper surface concaved to receive therein adjacent portions of the spring in free slidable relationship whereby the forces generated by the torsionally loaded spring are carried solely on said support member and the spring is restrained against eccentric displacement.

2. The invention according to claim 1 in which the torsion spring comprises a pair of oppositely wound coils connected together by a rearwardly extending connecting portion and the spring support pad being divided into two spaced-apart sections forming a passageway through which connecting portion extends, each section supporting one of said coils.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2202630 *May 23, 1938May 28, 1940Mary HauberChair
US3339973 *Jan 5, 1966Sep 5, 1967Doerner Products Co LtdTorsion spring chair control
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3709535 *Jan 18, 1971Jan 9, 1973Rothermel HHinge iron for posture chair
US3813073 *Apr 21, 1972May 28, 1974Steelcase IncDual torsion bar chair control
US4067610 *May 10, 1976Jan 10, 1978Hoover Ball And Bearing Co.Chair control mechanism
US4101166 *Jul 7, 1977Jul 18, 1978Gf Business Equipment, Inc.Chair control mechanism
US5114211 *Sep 12, 1990May 19, 1992Simon DesantaChair, in particular an office chair
US5452937 *Sep 19, 1994Sep 26, 1995Pro-Cord S.R.L.Plate for connecting the seat, back and legs, especially for chairs
US5630647 *May 26, 1995May 20, 1997Steelcase Inc.Tension adjustment mechanism for chairs
US5630649 *May 26, 1995May 20, 1997Steelcase Inc.Modular chair construction and method of assembly
US5782536 *Feb 17, 1995Jul 21, 1998Steelcase Inc.Modular chair construction and method of assembly
US5873634 *Jan 8, 1998Feb 23, 1999Steelcase Inc.Modular chair construction and method of assembly
US5951109 *Apr 30, 1997Sep 14, 1999Haworth, Inc.Chairback with side torsional movement
US5979988 *Dec 31, 1998Nov 9, 1999Steelcase Development Inc.Modular chair construction and method of assembly
US6059363 *Jan 30, 1998May 9, 2000Haworth, Inc.Chairback with side torsional movement
US6220664 *Aug 26, 1999Apr 24, 2001Ming-Hao LeeBase structure for chair seat
US6659554 *Feb 1, 2002Dec 9, 2003Wen-Fa SuAdjustment device of a chair backrest
US7614697 *Jun 17, 2008Nov 10, 2009Fon Chin Industrial Co., Ltd.Coupling mechanism interposed between a seat and a back of a chair to prevent a reclining motion of the back from tilting the seat
US8348341 *Sep 21, 2010Jan 8, 2013Yun-Chien HsiaoChair assembly with a backrest-adjusting device
US9241573 *Oct 22, 2014Jan 26, 2016Zhongshan Shi Songlin Furniture Co., Ltd.Resilient-support adjusting device of chair backrest
US20120068509 *Sep 21, 2010Mar 22, 2012Yun-Chien HsiaoChair assembly with a backrest-adjusting device
U.S. Classification297/301.3, 297/303.3, 248/575
International ClassificationA47C3/02, A47C3/026
Cooperative ClassificationA47C3/026
European ClassificationA47C3/026