Chair

Application filed December 20, 1918. Serial No. 267,576.

To dll whom it may concern:

Be it known that I, Earl Thompson, a citizen of the United States, residing at the city of New York, in the county of New 5 York and State of New York, have invented certain new and useful Improvements in Chairs, of which the following is a specification.

My invention relates to improvements in 10 chairs, and is particularly adapted for use in school chairs and seats adapted to orthopedic treatment and other chairs which are intended to be used continuously for any considerable period of time. In chairs of 15 this character, it is desirable that the back of the occupant be supported in such manner as to relieve the muscles from undue strain and stretching forces and that there be provided adequate support for the lower 20 back to maintain the lumbar curve and adjustable as may be required for each particular case, to accommodate the varying ana, tomical curves, variation of structure and bulk of clothes and no fixed curve can be 25 devised to give proper support to all individuals. There must be direct support applied where it is most needed to prevent flexed and twisted positions and each chair should be fitted to a individual user and 30 also adjustable as to the height of the s.eat so that the legs of the occupant of the chair may rest on the floor in a natural position. It is also important that the back of the chair should be vertical and not be inclined, 35 as this construction tends to cause the user to assume a wrong position and to bring the upper spine, chest and neck forward in an unnatural posture. The upper back of the chair should not extend above the level of 40 the shoulders of the user, but preferably to about that point when seated in a natural position. The chair back should be So constructed as to support the back and spine of the occupant in the natural position and 45 maintain the torso, neck and head when seated in the position which should be assumed when standing erect. Neglect or failure in this respect tends to produce curvature of the spine, scoliosis, kymosis and 50 other deformities. The object of my invention is to overcome the conditions which exist in the chairs now in use and to provide a chair which will produce the above mentioned desired results and will prevent and 55 correct spinal curvature and deformity.

I accomplish this object by the device illustrated in the accompanying drawing in which Figure l.is an elevation of my improved chair; Fig. 2 is a section on the linn 2—2 in Fig. 1; Fig. 3 is a detail of the 60 support for the lower back, with parts broken away, and Fig. 4 is a section on the line 4—4 in Fig. 1. Similar characters refer to similar parts throughout the several views. . _ 65

Referring to the drawings, 1 is a chair haying a back formed of two uprights 2 2 which extend to about the level of the shoulders of the occupant of the chair and carry at their upper ends a cross piece 3 pivoted 70 between the uprights 2 2 on pins 4 4 which are preferably secured in the cross piece 3 by means of glue or the like and are each provided with a head 5 which turns freely in the upright 4 and are prevented from be- 75 ing withdrawn from the upright 4 by means of collars 6 6 therein whereby the cross piece 3 is adapted to swing on the pivots 4 to adjust itself to the correct chest position and upper back of the occupant of the chair 80 and is limited in its movement by pins 7 inserted in the uprights 2 or in other suitable manner. Between the uprights 2 and above the seat of the chair, I provide a lumbar rest 8 which is preferably convex 85 in the direction of the front of the chair and is adjustable vertically. For the purpose of vertical adjustment, I prefer to provide in the inner face of the uprights 2 a plate 9 having a plurality of perforations 90 or seats 10 to receive the rounded heads 11 of the pins 12 which are mounted in the rest 8 and are normally pressed out into the seats 10 by springs 13 whereby the rest 8 may be adjusted vertically to accommodate 95 the anatomical lumbar curve of the occupant, with space between the seat of the chair and the lumbar rest 8 to accommodate the buttocks and clothing. I also preferably provide on the upright 2 adjacent the ends 100 of the rest 8 a guide bar 14 having a longitudinal slot 15 in which slides a set-screw 16 which may be turned down upon the bar 14 to bind the rest 8 in the desired position, _ My device being thus assembled is de- 10 5 signed to be adjusted to an individual user, for which purpose the lumbar rest 8 is positioned on the uprights 2 to provide proper support fot the back of the occupant of the chair in the region of the lumbar vertebra 110 of said occupant and the cross bar 3 will, by reasori of its flexible attachment to the

1,375,868 uprights 2, adjust itself to the proper and natural position for supporting the upper back and shoulders, whereby the back and chest of the occupani will be supported in 5 such manner as to relieve the muscles and vertebrEe from undue strain and stretching forces, and direct support will be supplied where it is most needed to prevent a flexed and twisted position in the occupant. .

I also provide on the bash 1' of the legs of the chair 1 an extension screw I² whereby the height of the chair may be adjusted to the occupant.

I have shown the back applied to a chair 15 seat of the usual construction but I do not intend to so limit my invention as it is obvious that it may be applied to chairs of any desired form and is particularly adapted for use in connection with school 20 chairs, orthopedic chairs and the like.