US577824A - Adjustable school desk and chair support - Google Patents

Description

(No Model.)

B. P. ELLIOTT. ADJUSTABLE SCHOOL DESK AND CHAIR SUPPORT. No. 577,824.

Patented Feb. 23, 1897.

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RICHARD P. ELLIOTT, OF NASHUA, NEW HAMPSHIRE.

ADJUSTABLE SCHOOL DESK AND OHAIR SUPPORT.

SPECIFICATION forming part of Letters Patent No. 577,824, dated February 23, 1897. Application filed January 30,1896. Serial No. 577,413. (No model.)

To aZZ whom it may concern.-

Be it known that I, RICHARD P. ELLIOTT,

of Nashua, in the county of Hillsborough and State of New Hampshire, have invented certain new and useful Improvements in Adj ustable School Desk and Chair Supports, of which the following is a specification.

My invention relates to adjustable seats or chairs, and has particular reference to that class or type in which a base receives a bracket attached to the seat, the said base and bracket being provided with intermeshing teeth.

The object of my invention is to produce an improved and simple construction whereby a fine adjustment may be obtained, the strength of the parts increased without increasing the weight, and also whereby the parts will be entirely prevented from relative movement sidewise or wabbling.

To these ends my invention consists in the construction and combination of parts, substantially as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a side elevation of my improved chair-base and bracket. Fig. 2 is an enlarged section on line A A of Fig. 1. Fig. 3 is a section on line B B of Fig. 2.

Similar letters refer to similar parts throughout the several views.

The chair-base is represented at a, and b represents the bracket-slide, which is adapted to slide vertically in an opening or socket in the top of the chair-base a, its upper end being provided with the bracket 0, which is attached to the bottom of a chair-seat by means of suitable screws.

d and d represent two set or binding screws which operate in threaded holes in the walls of the portione of the chair-base and operate tohold the bracket-slide firmly against the inner wall of one end of the socket 6, thereby holding the bracket-slide securely in place.

Two ratchet-teeth f f form part of and project inward from the inner walls of the socket e, and the faces of said ratchet-teeth f f are at an angle to said inner walls, as shown, and deflect outward toward the binding-screws cl d. On the bracket-slide b are located the corresponding teeth g 7*, there are engaged.

being a vertical series of such teeth, as indicated in Fig. 1. The faces of these teeth g g converge in the direction away from the screws d cl.

The object of having the ratchet-teeth ff and g 9 set on the angles shown is so that when the bracket-slide is in the position shown in Fig. 2 the said ratchet-teeth will be wedged together, as shown, thereby giving four points of contact, to wit: at the points of contact between the said ratchet-teethff and g g and the bearings hand?) on the inner walls of the socket. Said four points of contact securely hold the bracket-slide b in the position shown in Fig. 2 when the bindingscrews are tightened, thereby absolutely preventing any wabbling or lateral movement. As shown in said Fig. 2, the extreme points of the teeth f f are so inclined relatively to each other that the wedge-shaped portion of the slide b between the teeth 9 g is firmly bound or wedged between the teeth f f" even if the parts are not quite in contact at h and 1'.

7s represent the spaces in which the ratchet-teeth f f run when the bracket-slide b is being adjusted vertically to different heights, the said spaces being sufficiently wide to allow a free movement of the ratchetteeth in them.

The method of adjusting my improved adjustable chair-base and bracket is as follows: First the binding-screws are turned outward until their points are even with the inside wall of the socket. Then the bracket-slide is moved in the direction shown by the arrow in Fig. 1 until the teeth f and f are in the spaces 70 70. Then the bracket-slide is adjusted vertically to the desired height and then moved laterally in the opposite direction to that shown by the arrow until the ratchet-teeth Then the binding-screws are tightened, which completes the adjustment, the teeth being wedged together.

Heretofore it has been customary in constructing chair-bases and brackets to have the supporting-teeth on one or both edges of the bracket-slide, which tends to weaken the bracket-slide and catch the clothing of the pupils. In the improvement herein shown the above objections are entirely overcome.

VVhiIe I have shown and described my inwhich are inclined or wedge-shaped, substanvention as adapted for chair-seats, it is obvitially as described. ous that it may also be used in connection In testimony whereof I have signed my with school-desks as well. name to this specification, in the presence of 15 5 Having now described my invention, what two subscribing witnesses, this 30th day of I claim is November, A. D. 1895. I,

The combination with the base at having socket e, screw d and two inwardly-project- RICHARD ELLIOTT ing and laterally-inclined teeth f f, of the Witnesses: 1o slide 19 having bearing faces or portions h z', MILTON A. TAYLOR, and two sets or series of teeth g g the faces of I HENRY H. J EWELL.

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