US249259A - Half to frederick a - Google Patents

Description

(N0 Mbdel.)

H. B. RIEH LE. WEDGE GLAMP.

Patented Nov. 8,1881.

UNITED STATES PATENT OFFICE;

HENRY B. RIEHLE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE- HALF TO FREDERICK A. RIEHLE, OF SAME PLACE.

WEDGE-CLAMP.-

- SPECIFICATION forming part of Letters Patent No. 249,259, dated November 8, 1881.

Applicrtion filed May 20, 1881. (No model.)

To all gvhom it may concern:

Be it known that I, HENRY B. RIEHLE, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a 5 new and useful improvement in a wedge of peculiar shape, to be used in holding boiler-plate or flat specimens in a testing-machine, or be applied for other purposes to resist a strain, of which the following is a specification.

The object of my invention is to obtain a perfectly central pull or stress on flat material without the possibility of tearing from the sides or edges, a difficulty heretofore existing in wedge-gripes generally.

My invention consists of a wedge havingits cut face which gripes the specimen slightly raised through its center longitudinally its entire or partiallength. The center line can be approached either by a curve or in a straight 2o manner.

I am aware that wedges with curved backs, and wedge seatsor lilies with backs or faces arched are made to accommodate specimens of uneven thickness. They, nevertheless, will p not prevent'a twist or torsion if opposite corners of specimens above and below are unequal in thickness or the surfaces are harder, or it teeth of wedges are worn away unevenly, allowing slipping or shifting of the specimen also. In my improved wedge the specimen is engaged at once through the axial line, and presses continuously a little harder at the center (throughout the entire test) than it does on the edges. The edgesarethusrelieved underall circumstances, and a side pull causing a tear 5 is impossible, and anydanger from a twist prevented. I do hereby declare that the following is a clear, full, and exact description thereof, reference being had to the accompanying drawings, in which similar letters and figures 40 indicate like parts.

Figure 1 is a plan view of an ordinary specimen holder or clamp. Fig. 2 is a vertical sectional view, and Fig. 3 is a modification of the wedge-face.

The clamp A-is held in position in the machine by the bolts B B.

In Figs. 1,2,and 30 0 represent the wedges. In Fig. l the faces ofwedges G G, which press against the specimen D, are curved, while in Fig. 3 the faces are straight to the center line. Both are shown more curved or inclined than in reality.

The letters e on Figs. 1 and 2 represent a steel pin held by a set-screw, which acts as a guidein upper and lower clamp, to brin g specimens to the center perpendicularly.

What I claim as my invention is- A wedge adapted to hold flat bars in a testingmachine, having its vise or biting-face 6o throughoutits entire length, or a portion th ereof, raised in a central longitudinal line, substantiall y as described, and for the purpose set forth.

HENRY B. RIEHLE.

Witnesses:

CHARLES RoBsoN, WILLIAM F. HOGAN.

Images