US 2942652 A
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Description (OCR text may contain errors)
Jun 2 1 0 w. c. CHAPMAN 2,942,652
SEATS Filed Dec. 13, 1956 Inventor Attorney 5 United States Patent SEATS William Charles Chapman, 48 Great Eastern St., London, EC. 2, England Filed Dec. 13', 1956, Ser. No. 628,151 Claims priority, application Great Britain Och-15, 1956 2 Claims. 01. 155-478) This invention relates to seatsfor various purposes but has particular reference to chair seats of the kind adapted to be fixedly or detachably mounted in or upon a wooden seat frame.
The object of the present invention is to provide an improved form of seat construction designed to comply with the physical contours of the body and to prevent the upward spinal pressure which is a common source of discomfort when a person sits for a prolonged period upon a seat of normal type.
According to the invention a seat comprises a cushion of resilient or yieldable material and a rigid support therefor characterized in that the outer portions of the cushion are so constructed and supported that the central portion of the cushion can yield freely in a downward direction for the purpose of insuring that the weight of the sitter is distributed away from the central portion of the seat.
According to one form of the invention a chair seat comprises a frame having a central aperture of substantial dimensions to afford the minimum essential support to the sitter, and a covering of resilient or yieldable material extending over the entire area of the seat to cushion the surface of the frame but capable of yield ing downwards to a substantial extent through the aperture to afford the maximum degree of comfort.
Reference will now be made to the accompanying drawings in which:
Fig. l is an inverted plan of a chair seat constructed according to the invention,
Fig. 2 is a cross-sectional view of the seat taken on the line AB of Fig. 1,
Fig. 3 is a cross-sectional view of a modified form of construction, and
Fig. 4 is a perspective view, partly in section showing a seat operatively mounted in a chair frame.
In the construction illustrated and referring first to Figs. 1 and 2, the improved chair seat is constructed from a frame which may conveniently be cut from a single sheet of plywood. This frame consists of a relatively narrow flat rim a surrounding a central aperture b. This frame is surmounted by a cushion c which may consist of a pad of cellular rubber, cellular plastic or other similar material co-extensive or nearly co-extensive in area with the frame. In practice it is preferred to support this cushion upon interlaced strips d of rubber or fabric extending at right angles or at any other angle across the aperture in the frame a and fixed to the upper surfaces thereof.
The use of these strips is not essential to the invention in all cases but they afford a useful support for certain kinds of cellular media and have the advantages of assisting the rapid recovery of the seat after use and of retarding disintegration of foamed or sponge-like media.
The dimensions of the central aperture b remain substantially constant to accord with the dimensions of the human. frame but for most practical purposes the maximumwidth of this apertu re should be oftheorder of 10 toll inches.
The seating is finishedxwith anoutercoveringgeof fabric, leather, plastic or other-upholstery material. This covering.
When a seat asl above described is in use the-weight of the sitter is taken:- by the: frame a, the cent'ral' portion of the cushion being: depressed through-the aperture b in the frame in conformity with the -contours of the" human seat resting: up'on'it; Thedesign is such that the depression of the cellular medium c through the aperture b takes place' toa'substanti'al degree. In this mannerthe seat not only provides a comfortable con formation but' the aperture b insures'that the weightof the person seated is distributed away from the central portion of the seat and therefore away from the central nerves and circulation center to the outer extremities of the seating area. This distribution of the weight also insures that the central portion of the seat cannot set up the resistance which commonly produces a tiring upward pressure on the region at the base of the spine of the sitter. 1
In certain applications of the invention it may be found desirable to increase the thickness of that portion of the cushion c immediately above the frame. In certain applications of the invention it may be necessary to superimpose the deformable cushion upon a solid frame, that is one without the aperture b, in which case it is necessary to increase the thickness of the peripheral portions of thecushion. Such a modification is shown in Fig. 3 wherein h indicates a solid supporting base and i indicates the thickened or built up edge portions of the cushion. These edge portions may be of any convenient width to accord with the type of seating and may be of internal arched or recessed structure. The central portion k of this form of cushion is depressed when the seat is occupied to the position shown in broken lines and thus functions in the same manner as the seat shown in Figs. 1 and 2. The height of the seat is built up according to the density of the cushion material employed to such a dimension as will prevent any possibility of contact with the solid base h when the weight of an average person is imposed upon the seating.
One method of utilizing a seat constructed as above described is to mount it in a wooden seat frame 1 of a bentwood chair as shown in Fig. 4 wherein the seat forms an easy fit within the frame which is formed internally with a ledge g or is otherwise formed or provided with means on which the outer edge portion of the seat is supported.
In all forms of the invention herein described the edge portions of the seating may be discontinuous in that the central peripheral portion at the front may be cut away.
1. In a seat support structure, a rigid fiat-sided frame having a single central aperture therethrough, said aperture being formed to conform to the contour of the human frame and including an arcuate front edge having a selected radius of curvature and an arcuate rear edge having a selected radius of curvature of substantially lesser magnitude than the radius of curvature of said front edge; and a resilient flexible imperforate cushion supported on said frame over said aperture and having a bottom face spaced above the top of said frame in opposed unflexed relationship to said aperture, said cushion having a flat sided substantially peripheral integral portion projecting downwardly from said bottom face in supported bearing relation .to said frame peripherally 2 Ina'seat-su'pport structure, at
having asingle through central aperture approximately: 10-11 inches in width, said aperture beingiotmed to around a d near the edges ofxsaid aperture, said cushion being sulficiently yieldable by the weight of'a human corresponding portion of thebody;
portions of the seat and relieve upward pressure on the' conform to the contour of the human frame and includ: ing 'arcuatefront edge having a singleselected radius 'of curvature and; an arcuate rear edge, having 'aJsingIe;
selected radius of curvature of substantially lesser magnitudethan the radius of curvature of said-front :edge;
7 and a resilient flexible imperforate cushion supportedon' 7 body so thatjthe central portion thereof is capable of V being depressed through said aperture in conformity with the contoursof the humanrframe to 'thereby 'uniformlyl. distribute the weight of the human body to the peripheral ing to the contour of said aperture and pr'r'ijet'kzt'ing'down wardly from said bottom face in supported bearing relation to said frame peripherally around and near the edges of said aperture, said cushion being sufficiently yieldable by the weight of a human body so that the central portion thereof is capable of being depressed through said aperture'in conformity with the contours of the human frame to thereby uniformly distribute the weight of the human body to the peripheral portions of the seat and relieve upward pressure onthe. lcorresponding portion of said frame over said aperture and having a bottom lface. spaced above the top ofsaid frame in opposed unflexed' A relationship to'said aperture, said cushion having a flatsided substantially peripheralintegral portion correspond Referencesof patent 7 UNITED, stares PATENTS 2,488,728 Koppun QN'ov. 22'; 1919 2,532,713' easements.--" Dec. 5, 1950 2,552,039 Flogaus May 8, 1951 FOREIGN PATENTS 7 "105,007 Australian; -Aug.-3'1,'193s,