US468027A - Music-desk for pianos - Google Patents

Description

(No Model.) I

E. PETERSON. MUSIC DESK FOR PIANOS.

No. 468,027. Patented Feb. 2, 1892;

INVENTOR:

WITNESSES:

A TYS.

UNITED STATES PATENT OFFICE.

EMANUEL PETERSON, OF BOSTON, MASSACHUSETTS.

MUSIC-DESK FOR PIANOS.

SPECIFICATION forming part of Letters Patent No. 468,027, dated February 2, 1892. Application filed August 21, 1890- Serial No. 362,695. (No model.)

To 0. whom it may concern.-

Be it known that I, EMANUEL PETERSON, a sub ect of the King of Sweden, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented a new and use-' in its pulled-out position in full lines and in its closed-up position in dotted lines.

A represents the front board of a piano, and I3 the music-desk hinged thereto at C, so that it can swing freely in and out. A plate-spring D is secured to the music-desk at E, and is pivoted at F to a swinging arm G, which is pivoted in the piano-frame at H in such aposition that it will hold the piano-desk in its outer position when pulled out and in its inner position when pushed in, the spring yielding sufficiently to pass over the dead-center when the proper amount of force is applied, it being also sufficiently stiff to hold the desk open in spite of the Weight of the music sheet or book tending to close the same.

It is evident that the spring D forms a spring-brace, which not only holds the musicdesk in its outward and inward positions,but tends to throw the same into such positions, so that it cannot remain at any intermediate angle. In other words, the spring in passing from its inner to its outer position is moved over a dead-center.

WVith the construction described the springfrom the pivotal point of the desk as a center. It will be observed that arcs struck from these two points, respectively, do not coincide, but intersect substantially at the points occupied by the pivot F, as shown in full and in dotted lines. From these considerations it will be evident that when the desk is moved inward the spring must be compressed, and after it passes a certain intermediate point its tension will throw the desk quickly into the dotted-line position, when the tension of the spring is again relieved. In novingthe desk from open to closed position the operation is the same. In this movement of the desk the pivot F travels back and forth across the plane of the piano-front, assuming in the one case a position in advance of said plane and in the other case one in the rear of the plane. When the desk is closed, it fits an aperture or seat in the frame, and to permit this the pivots connecting arm G With the frame and the brace are offset, so that the brace may be at-,

tached tothe desk, but the arm connected to the frame at a point to one side of the desk.

Having thus described my invention, what I claim as new is 1. The combination, with a piano-frame-and music-desk pivoted thereon and adapted to swing from an inner to an outer position, of a brace of spring metal connected to both frame and desk, and a moving pivot forming one of the points of attachment of the spring, which is behind the plane of the piano-front when the desk is closed, but is moved to a position in front of said plane when the desk is open.

2. The combination of a piano-frame and desk pivoted thereto and adapted to spring from an inner to an outer position with a brace of springy material acting to positively throw the said desk into either one of its eX- treme positions and connected at offset points at one end with the frame to one side of the desk and at the other end to the desk itself, substantially as set forth.

, 3. The combination, with the piano-frame,

of the music-desk pivoted thereto and adapted to swing from-an inner to an outer position,

a spring-brace connected at one end to the music-desk, and a swinging arm connecting the other end of the brace to the piano-frame, so as to hold the desk in either of its extreme positions and throw it into one of its said poof the desk for a center, and, second, with the 10 sitions when placed at an intermediate angle. frame, so that it tends, also, to move in a sec- 4-. The combination, witha piano-frame and 0nd intersecting are around this latter point, desk pivoted thereto, of a spring-brace having as set forth.

one end attached to one of the above-named 1 Y r w r parts and a moving pivot connecting its other ILMAA UEL PE FERbOL' end to the second part, which pivot is eon- Vitnesses:

neeted, first, with the desk, and so tends to N. F. HAYES,

move in the are of a circle having the pivot l E. M. BENTLEY.

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