US358660A - Adjustable stool - Google Patents

Description

(.No Model.)

` R. E. HAMMER.

ADJUSTABLE STOOL.

Patented Mar. 1, 1887.

Ffc.

N. PUERS. Pholu-Lilhugmpher, washington, D. c.

UNITED STATES ROBERT EfHAMMER, OF PHILADELPHIA, PENNSYLVANIA.

ADJUSTABLE STOOL.

SPECIFICATION forming part of Letters Patent No. 358,660, dated March 1, 1887.

Application filed February S, 1F86. Serial No. 191,191. (No model.)

.To @ZZ whom it may concern,.-

Be it known that I, ROBERT E. HAMMER, a citizen of the United States, and a resident of Philadelphia, Pennsylvania, have invented certain Improvements in Adjustable Stools, of which the following is a specification.

My invention relates to that class of adjustable stools or seats in which the top of the stool is supported upon opposite frames, each consisting of two bars pivoted together at a point midway,or thereabout,betweeu their opposite ends, so that when said bars are caused to turn upon their pivots the frameis expanded or contracted and the top of the seat raised or lowered.

My invention consists of certain improvements in the construction of adjustable stools of this class and in the devices for adjusting the stool and locking it in any desired position.

In the accompanying drawings, Figure lis a longitudinal section of a stool construct-ed in aecordance with my invention, the upholstered top of the stool being removed 5 Fig. 2, a transverse section of Fig. 1 on the line l 2; Fig. 8, a plan View of Fig. l; Figs. 4 and 5, detached perspective views of parts of the structure, and Fig. 6 an enlarged section of part ofthe locking device.

Each of the opposite supporting-frames ofthe stool consists of two curved or inclined bars, A A, suitably connected and braced by transverse rods a, and pivoted together at or about the center, the pivot-pins being formed in the present instance by the ends b of the central bar, a, of the frame.

The top frame, B,of the stool rests upon the rounded upper ends of the bars A A of the side frames, and said frameB isvertically confined to the bars A by means of links d, secured to or forming part of transverse plates D, the opposite ends of which are adapted to grooves e in the side bars of the frame B. On

each plate D, at or about the center of thesame, is a depending lug, f, the lugs of the two plates being connected together by a spring, F, the tendency of which is to draw the plates D D toward each other, this movement being transmitted by the links d to the upper ends of the bars A A of the supporting-frames, so that in the absence of any retaining device the spring would draw the upper ends of the bars A A together, and thus elevate the seat to the full height, while pressure upon theseat would overcome the tension ofthe spring and separate the upper ends ot' the bars A A of each supportingframe, so as to lower the seat to the full extent. In order, however, to lock the seat at any desired elevation, I provide each ol" the plates D with a projecting rack, g, a pinion, h, engaging with the opposite racks, and being hung to a` stud, c, 011 a central transverse plate, G, secured to the top frame, B, of the stool. To suitable bearings on this plate G is adapted a lockingbolt, H, which has a tooth, fi, adapted to engage with thc teeth of the pinion lt and prevent the rotation of the same, a spring, m, acting upon the bolt and tending to cause the same to engage with the pinion, from which the bolt may be withdrawn, however, by means of an operating-rod, n, which projects through an opening in the frame B of the stool, and

has a catch, p, for engagement with a retaining-plate, t, on said frame, the outer end of the rod having a ring or other suitable handle, w, by which it may be readily manipulated.

Thepinion 7L is held in position vertically on the stud `c by means of the locking-bolt, which passes transversely beneath the pinion and supports the same, the use of a screw bolt or pin as a pivot for the pinion being thus rendered unnecessary and the fitting together of the parts somewhat simplied.

When it is desired to depress the stool, the rod o1, is iirst lifted so as to free its catch from the control ot' the plate t, and is then drawn outward, thereby withdrawing the bolt H from engagement with the pinion h, the racks y being thereupon free to move in opposite directions when pressure is exerted upon the seat sufiicient to cause the forcing apart of the upper ends ofthe bars A A of each supportingframe. When the stool has been depressed to the proper' extent, the rod n is released, so that the bolt H, under the influence of the spring m, again engages with and locks the pinion lt, the rod n being at the same time retained by engagement of its catch p with the plate t.

When it is desired to raise the stool, the

locking-bolt is withdrawn in the same manner IOO vnecessary in order that the said racks may re-v tain a position parallel with the frame B, whatever the angle assumed by the bars A, and in the present instance the plates D and links d providesuch a pivotal connection for the racks,

" in addition to their function of confining the frame B to the bars A, and this construction is preferred, although not absolutely essential to the proper carrying out of my invention. The plates D also serve as means whereby the pull of the spring F is always eXertedin aline directly parallel with the line of thrust of the racks g.

Although I have shown and described my invention as applied to a stool or seat, it will be evident that it can be applied as well to tables or desks, the frame B in this case being secured to or forming part of the top of said table or desk.

claim as my invention 1. The combination, in an adjustable stoolN or like article of furniture, of a supporting frame consisting of pivoted bars, with the frame B, carried by said bars, rack-and-pinion mechanism receiving movement from said bars, a locking bolt or catch movable into or out of engagement with said pinion, and a spring acting upon the upper ends of said bars of the supporting-frame, and serving as a means for drawing said upper ends of the bars together tially as spccied.

2. The combination of the pivoted bars A, the frame B, carried thereby, the plates D, having racks g g and connected to the bars A, a pinion gearing into said racks, a locking-bolt for said pinion, an operating-rod connected to the bolt, anda retainer for said rod, all substantially as specified.

3. The combination of the pivoted bars A,

.the frame B, supported thereon, the plates D,

and thus elevating the frame B, all substan- In testimony whereofl have signed my name to this specication in the presence of two subscribing witnesses.

ROBERT E. HAMMER.

Witnesses:

WILLIAM D. CONNER, HARRY SMITH.

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