US388417A - School-desk - Google Patents

Description

#(N wel M. W'. RIDDER.

SCHOOL DESK.

No. 388,417 Patented Aug. 28, 1888.

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UNITED STATES PATENT OFFICE,

MOSES WV. KIDDER, OF LINCOLN, MASSACHUSETTS.

SCHOOL-DESK.

SPECIFICATION forming part of Letters Patent No. 388,417, dated August 28, 1888.

Application filed February 14. 1888. Serial No. 264,010. (No model.)

To all whom it may concern.-

Be it known that I, MosEs W. KIDDER, a citizen of the United States, and a resident of Lincoln, in the county of Middlesex and State of Massachusetts, have invented new and use ful Improvements in School-Desks, of which the following, taken in connection with the accompanying drawings, is a specification.

Of the accompanying drawings, forming a part of this specification, Figure lis a plan showing the top of a desk closed down, a portion being cut away. Fig. 2 is a cross-section on the line A B of Fig. 1, with top of desk closed down. Fig. 3 is a like section showing the desk open or the top raised to an angle.

Similar letters referto similar parts through out the several views.

This invention consists in certain improvements in school-desks, whereby they may be made more suitable for the various uses required of them in reading and writing.

The object of this invention is to correct a manifest fault of position of pupils in school when using the desk in reading or study. As the book lies upon the ordinary school writ ing-desk, it necessitates a malposition of the body in bending forward over the book, and the eye, falling at an angle upon the page, gradually but certainly ultimates in deformity and consequent astigmatism and myopy.

In the construction of a school-desk embodying my improvements I provide supports 'in any of the ordinary forms in common use. Upon these the door or bottom of the desk rests and is rml y secured. Fixed to and rising from this floor vertically upon three sides are the right and left band sides D and the back side ofthe desk. Extending across from one side to the other and projecting a little over the vertical sides D, and covering the top edge of the back side, is immovably fixed a part of the top T, about tive inches wide, in which is placed the ink-well. I neXt provide the movable or adjustable top t, of the same length as the fixed portion T and about seven inches wide. Upon the under side of this movable top t, near the front edge, and projecting downwardly at a right angle to the under surface and parallel to the ends of the 5o desk, are xed the combined friction-plate hinges77 a, one near each end and at such a the front edge of the desk.

distance from each other that when the movable top t is in its position the outer faces of the friction-plate hinges a fit nicely against the inner surfaces of the two vertical sides D of the desk, against which the said friction-hinge plates are pressed by the friction-elani ps b, provided for that purpose, and secured on the inner surface of the vertical sides D of the desk by adjustable screws Z1. The friction hinge plates a turn upon center bolts, a', which pass through them and the vertical sides D near I next provide a ledge7 c, 'of wood, of the same length as the top t, about three-fourths of an inch thick by one and a half inch wide. To the under edge of this ledge c, near each end, is rigidly fixed a lever, C, about seven inches long, parallel to each other in the saine direction and at right angles to the ledge, which rests upon one end of the levers. This ledge is next placed in its position against the front edge of the movable top t, the levers C passing backwardl y under, and are loosely attached by one end to the under surface of the movable top t, thus allowing limited motion of the ledge c to project or recede. These levers C, at each side supporting the ledge c, rest upon cam pins or studs d, fixed on the inner surface of the vertical sides D of the desk about one inch nearer the front edge of the desk than the center bolts, a', upon which the friction-plate hinges a turn.

Above each lever C is provided a spring, e, which, acting against the underside of the movable top t, together with the gravitation of the ledge and levers, holds the levers down upon the cam pins or studs d.

Having described the construction of my improved desk, I will indicate its operation.

When used for a writing-desk, the adjustable top t is placed in the position shown in Fig. 2, the ledge@ being flush with the top t. On raising the top t on its hinges a, as shown in Fig. 3, thus converting it into a reading desk, the friction hinge plates a, pressed against the inner surface of the vertical sides D of the desk by the frictionclamps b, enable the top to be arrested and held at any desired angle without any turning of screws or liability ot' falling from its position. As the top t is being raised to an angle approaching a Vertical, the levers C, resting upon the cam-pins loo d, are not permitted to fall concentrically with the adjacent edge of the top t, and the ledge c, resting upon the levers C, is automatically projected from the line of the upper surface of the adjustable top t to prevent books or slates from sliding from the desk. As the position as shown in Fig. 2 is resumed, the levers C, resting upon the camepins d, by action of the springs e or gravitation of the ledge and levers, or both, causeY the ledge to recede, so that it is again flush with the upper surface of the top t.

I am also aware that prior to my invention herein described curved friction arms or bars have been used to stay movable desk-tops in desired positions, in combination with and attached to an intermediate lid or frame, as shown in United States Patent No. 226,842; also, as shown running down toward the i'loor through the desk in United States Patent No. 340, 847; also, friction-tight joints or hinges by which the desktop is hinged to levers, as claimed and shown in United States Patents Nos. 248,043 and 320,17 5, where the top rotates upon trunnions between upright standards; also, in United States Patent No. 163,605, the notched hinge-plate near the back side of the desk.

I am also aware of the adjustable ledge shown in United States Patent No. 163,605, which is partially rotary and not automatic; also, theledge shown in United States Patents Nos. 340,847 and 248,043, which are automatic. In the Aformer the top is hinged directly to the ledge, which is iixed at each end to the sides of the desk -and is immovable, and in the lat ter the top is hinged near the front edge to two levers, which support the cylindroid ledge; also, in United States Patent No. 329,175, in which is presented a reversible table with a xed ledge upon one side and none on the other, said table turning upon trunnions resting in upright standards at each side.

In the above references in Nos. 329,175 and 163,605 the usual space provided for books is whellysaeriticed. In Nos'. 226,842 and 340,847 the same space is largely encumbered by the mechanism, While in No. 248,043, and as shown in this specication, the said space is wholly economized.

It Will' be noticed that in none of the above references do the tops of the desks, which turn upon hinges near the front edge, hinge upon the inner surface of the vertical sides of the desk, as shown and described in this specification.

It will also be noticed that in none of the above references cited do the friction plates or arms depend upon frictional contact with the sides of the desk, but upon dogs or springs, as shown, entirely nnlil ethe mechanism herein shown and described.

What I claim as new, and wish to secure by Letters Patent, is

l. In a school desk, the combination of the adjustable top, the sector-shaped hinge-plates secured to the under side of said top and turning upon a pin at the center, the friction-clamp consisting ot' a bar secured at one end to the side of the desk and bearing at its other end upon the hinge-plates, and the adjusting-screw passing through the clamp-bar and engaging the side ofthe desk, as and for the purpose set forth.

2. In a schooldesk, the combination, with a hinged desk-top, of one or more levers secured to the under side of the desk-top, a ledge normally supported by said levers in position iiusli with the desk-top, and a stud on the desk eccentric to the pivot and adapted to engage the levers to throw the ledge upward when the desk-top is raised, substantially as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this 10th day of February, A. D. 1888.

MOSES V. RIDDER.

VVit-nesses:

FRANCIS J. KIDDER, RICHARD H. KiDDnn

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