US486186A

US486186A - T-square

Info

Publication number: US486186A
Authority: US
Publication date: 1892-11-15
Anticipated expiration: 1909-11-15

Description

(No Model.) 2 Sheets-Sheet 1.A

W. G. THORNTON.

1f-SQUARE.

No. 486,186. Patented Nov. 1,5, 1892.

- (No Model.)

2 Sheets- Sheet 2.'

W. G. THORNTON. '1T-SQUARE.

Patented Nov. 1.5, 1892.

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UNITED STATES PATENT OFFICE.

WINFIELD G. THORNTON, OF MINNEAPOLIS, MINNESOTA.

T-SQUARE.

SPECIFICATION forming part of Letters Patent No. 486,186, dated November 15, 1892.

Application led November 13, 1891. Serial No. 411,787. (No model.)

To a/ZZ whom it may concern,.-

Be it known that I, WINEIELD G. THORN- TON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in T- Squares, ot' which the following is a specification.

My invention relates to the well-known T- square used in drafting.

The object of the invention is to provide convenient means for adjusting the inclination of the blade of the instrument and for enabling the instrument when so adjusted to be accurately and readily moved along the draft-board. This object is accomplished by the devices illustrated in the accompanying drawings, in which- Figure 1 is a plan View of a portion of an instrument embodying my improvements in place on the drafting-board; Fig. 2, a central longitudinal section of the same; Fig. 3, a sectional detail of the head-plate; Fig. 4, a plan view showing a modification of the devices, and Fig. 5 a sectional view on the line w x of Fig. 4.

In said drawings, 1 designates a draftingboard, 2 the head of the instrument, and 3 its blade. The blade is attached by screws or otherwise to the under side of a plate 4, that is connected by a pivot 5 to a tongue 6, projecting from the,head. In the forward portion of the plate4 is a slot 7 in form of an arc of which the pivot 5 is the center, and through this slot projects a lug 8, formed on` or secured to the plate 2. The upper portion of this lug is threaded to receive a nut 9 for clamping the plate4 to the head-plate atany 'point of adjustment permitted by the slot 7.

This arrangement enables the blade to be turned on its pivot 5 to any angle within the limits of the slot and to be secured in place when so adjusted. A graduated scale 10 is provided in an arc along the edge of the head, and a pointer l1 at the end of the medial line of the blade 4 enables the angle of adjustment of the blade to be readily determined. Through the center of the lug 9 and the headplate is a hole 12 in which is abolt 13, having on its lower end a flat head 14, which engages the under side of a metal strip 15, that is secured to the drafting-board 1 with its outer edge parallel to but projecting beyond the edge of the board. A nut 17 on the threaded end of the bolt enables the head `14 to be clamped against the under side of the strip 15 to hold the instrument in place on the board.

In Fig. 4 is shown an instrument of similar construction, having the ends ofthe headplate 2 provided with rollers 18 bearing against the opposite edges of the strip 15, a groove 19 being cut in the board along the inner edge of the strip to admit the corresponding pair of rollers. The ends of the head-plate have slots 20, so that they may be sprung to cause the rollers to be held to` close contact with the strip to accurately guide the instrument along the board.

An instrument of the construction described can be readily adjusted to place its blade at desired angles to the edge of the board and can then be freely moved along the board or secured in fixed position, as desired. I I

Having described my invention, what I claim isy 1. In a T-square, a blade, a head, a plate providing a curved slot and pivotally connecting the blade and head, and a clamping device in such slot, permitting adjustment of the blade and serving to lock the plate to the head, substantially as set forth.

2. The combination, with a board having a projecting strip along its edge, of a T-square composed of a blade, a head, a plate pivotally connecting them and providing a curved slot, and a clamping device in such slot, permitting adjustment of the blade and serving to lock it to the head and to lock the instrument to the marginal strip of the board, substantially as set forth.

3. The combination, with a board having a strip along its edge and a groove coinciding with the inner edge of the strip, of a T-square having a slotted head adapted to engage the edges of the strip and to be moved along the same, substantially as set forth.

WINFIELD G. THORNTON.,

Witnesses:

R. BLUME, lP. H. GUNcKEL.