US2071974A - Chair back - Google Patents

Description

Feb. 23, 1937. w,-H. QUNLOC ZKE 1, 4;

' CHAIR BACK I Filed March 24, L936 4 v INVENTOR -WILLIAM H. Gumocna ATTORNEY,

Patented Feb. 23, 1937 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a chair back, and has for its purpose to afford a practical and durable back that can be manufactured economically, and serves to bring about a better posture of one occupying the chair and also to provide greater comfort by affording an effective and conforming support for the occupants back.

In a more particular aspect, the invention is intended to provide a seat back, of the type having a leather or fabric covering, with a yielding, forwardly protruding portion that may be curved convexly from top to bottom and projects sharply away from the main surface of the back, being located at a suitable distance above the seat, and thereby providing'a yielding or resilient support conforming generally to the small of an occupants back and in this fashion providing resisting but yielding support at'the'pointwhere it is most required to afford comfort and ease and maintain a correct posture.

To these and other ends, the invention consists in the arrangement and construction that will appear from the following description when read in conjunction with the accompanying drawing, the novel features being pointed out in the claims following the specification.

In the drawing:

Fig. 1 is a perspective View of a chair constructed in accordance with one embodiment of the invention, and showing the exterior thereof Fig. 2 is a front elevation of the back frame, partially broken away, and with the covering removed;

Fig. 3 is a vertical sectional view taken centrally of the back, and

Fig. 4 is a horizontal sectional view taken through one of the corner posts in the plane of the arm of the chair.

It will be understood that the invention is not confined to a chair construction, because it is equally applicable to any seat back, as for instance, to the type of seat used in railway coaches, automobiles, buses or the like, and the present disclosure is intended merely as illustrative of the manner in which the invention is applied to a chair structure.

Referring more particularly to the drawing in which like reference characters refer to the same parts throughout the several views, I designates the seat of a chair, and 2 are the corner posts of the back frame, which at their bottoms constitute the rear legs of the chair, said corner posts. being connected by the top portion 3 and bottom rail '4, which together constitute the back frame thatis 'of usual and .well known construction.

In applying the invention, it is necessary to support under the filling and covering materials, one 'ormore transversely arranged series of coil springs to provide the necessary yielding, forwardly protruding portion in the back, and this is preferably accomplished by employing three transversely arranged strips of webbing 5, which are stretched tightly and have their ends secured to the corner posts in any suitable fashion, and also two vertically arranged strips of web- .bing 6 which are likewise stretched tightly and secured to the top portion 3 and bottom rail 4, the vertical strips 6 being interlaced with the horizontal strips 5, as shown, and preferably extending in front of the upper and lower strips 5 and in the rear of the intermediate strip 5.

These strips of Webbing, which may be of jute or any other material suitable for this purpose, afford the supporting means for the springs which are preferably arranged in three rows or series transversely. The central series of coil springs are designated at 1, while the upper and lower series of coil springs are designated at 8, all of these having their rear ends sewed, wired, or otherwise attached to the strips of jute webbing 5 in the positions shown. The upper and lower series of springs 8 are of less length and terminate somewhat in the rear of the front ends of thecentral series of springs 'l, as shown in 'Fig. 3, for a purpose that will appear presently.

The corner postsare provided with blocks or portionsQ, which are preferably separate pieces rigidly joined andattached to the front edges of the corner posts, said portions 9 projecting forwardly and having convexly curved front edges that determine the curvature of the forwardly protruding portion of the back. The coil springs 8 in the upper and lower series are twisted somewhat away from their normal positions, that is to say, their free ends are bent upwardly and downwardly respectively, as shown in Fig. 3, and held in this general relationship by tie strings or wires secured to the outer ends of the springs, and also to the strips of webbing 6 or to the upper portion 3 and cross-rail 4, as the case may be. These tie members, designated at H), act to hold the upper and lower series of springs with their outer ends bent away from the central series, as shown in Fig. 3, and causing the outer ends of the springs in each vertical row to conform to the curvature of the front edges of the aforesaid blocks or portions 9 and likewise to the filling and covering material when the latter is stretched thereover and secured.

The blocks or portions 9 may be rabbeted to receive the arms H, or they may be made in separate portions secured above and below the arms H, and the arms may be attached to the corner posts in any convenient way. The blocks or curved portions 9 may also be formed integral with the corner posts, but by making these in separate pieces and attaching them to the corner posts, a stronger and more durable structure is afforded, as well as one that is less costly to manufacture.

After the coil springs have been located and secured, as illustrated in Figs. 2 and 3, the filling and covering material are stretched over the entire assembly and secured to the back frame in any suitable and convenient way, affording the finished construction illustrated in Fig. 1, where the forwardly protruding part 52 is shown having a convex curvature from top to bottom. This protruding part I2 is yieldable against the action of springs l and 8, and located above the seat I at such a point as to conform to the hollow or small of the back of an occupant and give the desired support at that point. Such a structure lends greatly to correct posture and also substantially increases the comfort, ease, and rest of one occupying the seat.

While the invention has been described with reference to certain details of construction, it is not confined to the precise arrangement shown, and this application is intended to cover such modifications or departures as may come within the purposes of the improvement or the scope of the following claims.

I claim:

1. A chair construction comprising a seat and a back including corner posts, said corner posts being provided with forwardly projecting portions located somewhat above the seat and having their front edges sharply curved convexly at their centers considerably above the seat and extending thence in gradual concave curves upwardly and downwardly, filling and covering material stretched over said curved portions and secured to the back, and three transversely arranged series of coil springs located beneath said filling and covering material, the central series of springs being of considerably greater length than the top and bottom series, and the springs in the top and bottom series being flexed away from the springs in the central series whereby the outer portions of the springs lie substantially in planes tangential to the curved edges of said forwardly projecting portions on the corner posts, affording a spring-supported forward projection sharply curved convexly and located above the seat at a point to engage and support the small of the back of an occupant, the back curving rearwardly in gradual concave curves from said projection both upwardly and downwardly and afiording a space therebeneath to receive the lower portion of the occupants back.

2. A chair construction comprising a seat and a back frame including corner posts, said corner posts being provided with forwardly projecting portions located somewhat above the seat and having their front edges sharply curved convexly at their centers considerably above the seat and extending thence in gradual curves rearwardly and upwardly and downwardly, webbing secured to the back frame and extending between the rear edges of said corner posts, filling and covering material stretched over said curved portions and secured to the back frame, and transversely arranged series of coil springs secured to said webbing and located beneath said filling and covering material, the outer ends of said springs being located in planes tangential to the forward curved bottom portions, said corner posts being provided with forwardly projecting portions located somewhat above the seat and having their front edges sharply curved convexly at their centers considerably above the seat and extending thence in gradual concave curves rearwardly and upwardly and downwardly, webbing secured to the back frame and extending between the rear edges of said corner posts, filling and covering material stretched over said curved portions and secured ,to the back frame, and three transversely arranged series of coil springs having their inner ends attached to said webbing and located in line with the rear edges of said corner posts, the central series of springs being of considerably greater length than the top and bottom series, and the outer portions of the springs in the top and bottom series being flexed away from the central series whereby the outer ends of the springs lie in planes tangential to said front curved edges of said forwardly projecting portions and afford a yieldable forwardly protruding and sharply curved portion positioned to engage the small of the back of the occupant, and portions located above and below which curve gradually rearwardly and upwardly and downwardly, the downwardly curving portion affording a space to receive the lower part of an occupants back.

4. A chair construction comprising a seat and a back frame including corner posts, said corner posts being provided with forwardly projecting portions having their front edges sharply curved convexly at their centers considerably above the seat and extending thence upwardly and downwardly in gradual concave curves toward the corner posts into which the front edges of the forwardly projecting portions merge along substantially continuous lines, covering material stretched over and conforming to said curved portions and secured to the back frame, and three transversely arranged series of coil springs, the springs of the central series being considerably longer than those of the top and bottom series and the outer portions of the springs in the top and bottom series being flexed upwardly and downwardly away from the center series affording a yielding and sharply convexly curved forwardly extending projecting portion located considerably above the seat to engage the small of an occupants back, and yieldable portions above and below the same which extend rearwardly in gradual curves, the lower of said rearwardly extending portions affording a recess at the rear of the seat below said sharply curved convex portion to receive the lower part of the occupants back.

WILLIAM H. GUNLOCKE.

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