US197763A - Improvement in book-supports - Google Patents

Description

A. CLARKE. Book-Support.

No. 197,763. Patented Dec. 4,1 77.

INVENTO2 WITNESSES: I i

ATTORNEYS.

N4 PETERS, PHOTO-LITHO .iRAFHER, WASHINGTON. D, Cv

UNITED STATES PATENT OFFICE.

' ALMON CLARKE, OF SHEBOYGAN, WISCONSIN, ASSIGNOR TO HIMSELF AND CHARLES A. SPENCER, OF SAME PLACE.

'IIVIPROVEMENT IN BOOK-SUPPORTS.

Specification forming part of Letters Patent No. 197,763, dated December 4, 1877; application filed July 23, 1877.

is a specification In the accompanying drawing, Figure 1 represents a side viewof my improved adjustable book-rest for chairs. Figs.2, 3, and 4 are, respectively, a rear view, top view, and an end View, partly in section, on line w on, Fig. 1, of the guide-clamp attached to chair. Fig. 5 is a top view of the upper clamp for regulating position of desk. Fig. 6 is a top view of deskholding screw-post and plate. Fig.7 is a side view of the entire device on smaller scale, shown as attached to an arm-chair.

Similar letters of reference indicate corresponding parts.

The object of this invention is to furnish a simple and cheap book-rest or adjustable desk, to be attached to the arm of a chair or other support, and be conveniently adjusted as to height and inclination toward the reader.

The invention consists of a double supporting-arm, which is adjustable as to height and angle of inclination on a screw-post of the chair by a toothed clamp and guide device, the bookrest being adjusted by a second toothed clamp device at the upper end of the supporting-arm.

In the drawing, A represents a double supporting-arm, of suitable length and strength, which is preferably made of a wrought-iron rod that is bentinto U shape, as shown inFig.1. The lower end of the double armA is clamped to a screw-post, B, that is rigidly attached to the chair or other object by a base-piece, C, secured by fastening screws. On the basepiece C is placed a disk, D, that is recessed at the rear side, so as to fit and bind on the basepiece C, and provided with radial teeth at the front side. A clamp-piece, E, that is placed on the top of the supporting-arm A,is grooved at the under side to bind on the double arm A, and provided with a solid guide portion, a, at one or both ends, that project through the space between the double arm, and interlock by one or more teeth with the face-teeth of the disk D.

A thumb-nut, E, binds on the clamppiece E, and clamps the toothed disk, supporting arm, and clamp-piece rigidly together. By loosening the thumb-nut the supporting-arm may be readily raised or lowered by being moved along the grooved clamp and guidepiece E, and also adjusted to any desired angle toward the point of support, by means of I the toothed portion of the clamp-piece and toothed base-disk turning on the screw-post.

The height and angle of the book-rest are thus adjusted by the sliding arm and lower clamp device.

The book-rest or desk F is connected to the upper end of the supporting-arm A by a screwpost, F, passing through the solid end casting A of arm A. The screw-postF is rigidly attached, by an end disk of plate F and fastening-screws, to back of the book-rest or desk. The end casting A is provided at the side facing the desk F with teeth d, radiating from the hole for the screwpost, and interlocking with one or more teeth, 01-, of the bracket or shoulder of the disk plate F from which the screw-post F extends. Athumb-nut, G, binds the end casting A and screw-post F together, and adjusts, by the interlocking toothed portions, the book-rest F to any desired angle of inclination on the supporting-arm. In place of the thumb-nut,a set-screw passing through solid end into the post may be used. The book-rest may thus, by the supporting-arm and the lower and upper clamp devices, be set into the manner set forth.

ALMON CLARKE. Witnesses:

J. D. SrEARNs, D. W. HALSTED.

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