US154891A - Improvement in adjustable pitch x b boards - Google Patents

Description

' 1. NULL. Adjustable Pitch-Boards.

I N0.154,891-. Patented Sept.8,18 74.

Wit asses: Inventor:

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THE GRAPHIC CO.PHDTl7-LITII.39& 41 PARK PLAE,N,Y;

UNITED STATES PATENT QFFIGE.

JOSEPH NOLL, OF POUGHKEEPSIE, NEW YORK.

IMPROVEMENT IN ADJUSTABLE PITCH-BOARDS.

Specification forming part of Letters Patent No. 154,891, dated September 8, 1874 application filed January 10, 1874.

, keepsie, in the county of Dutchess and State of New York, have invented a new and Improved Adjustable Pitch-Board, of which the following is a specification:

In the accompanying drawings, Figures 1 and 2 represent front elevations .of my improved pitch-board for carpenters and stair builders, one showing it in position when not in use, the other adjusted to the pitch and tread of the staircase ready for use.

Similar letters of reference indicate corresponding parts.

The object of my invention is to furnish for the use of stair-builders and carpenters an adjustable pitch-board, which may be set to any pitch of step and width of tread, as required, forming thereby a very useful and labor-saving instrument.

I Stair-builders at present cut a pitch-board of wood for every stair-case. This board frequently gets shrunk or warped, so that the necessary accuracy is not obtained, and that either a new one is required or time lost in correcting the inexact workmanship produced. For the purpose of dispensing with the former and remedying the latter defects, I have constructed a pitch-' board, which may be made of metal, with slidin g and slatted sides, arranged in such a manner'that the pitch and width of tread may be adjusted along the slatted sides of a rectangular corner-piece, and set rigidly, by suitable clamping-screws and connecting pieces, to be readily used on either side.

In the drawing, A represents the pitch -board, which is preferably made of iron or other metal, and produced of a rectangular corner-piece, B, side extensions 0, and connecting-pieces D. These pieces are so connected that a rectangular triangle with adjustable sides is formed, which serves by the extensions 0 for adjusting the pitch of the step and width of tread while the pieces D form the hypotenuse of the triangle, and give the necessary stability to the sides. The corner-piece B, as well as t e sides 0 and pieces D, are provided with s ts a, the extensions 0 sliding in those of corner-piece B, by means of set-screws b and guide-pin d. The pieces D, which connect the ends of the side extensions 0, are sl tted and extended in similar manner by pin and set-screw, so as to oorres 0nd in length to that of the sides. Short sl ts e, at the connecting ends of pieces D, serve, in connection with setscrews 6 of piec'esO, to bind their ends rigidly together. The slats a are preferably beveled on one side of the pitch-board, so that set-screws b may be sunk below the surface of the pieces, and allow the use of the pitch-board on either side and direction, as required.

When it is desired to adjust it for use, the length of tread is produced by the extension of one piece, (3, along corner-piece B, and the pitch along the other. The connecting-pieces D are extended at the same time by following the motions of the sides, and are exactly adjusted to the corner-edges thereof. The setscrews are then firmly tightened, and the pitch-board is ready for use without being liable to shrinking or warping, doing also more exact work, and forming a very durable and convenient instrument for stair-builders.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The adjustable pitch-board for stair-builders and carpenters, produced of rectangular corner-piece B, extension slide-pieces G, and connecting hypotenuse-pieces D, all being slatted and adjusted by means of guide-pins and set-screws to the pitch and tread of the steps, substantially in the manner and for the purposes described.

JOSEPH NOLL. Witnesses:

T. B. MOSHER, ALEX; F. Romans.

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