Samuel Blatchford

“ The defendants' blank, as in Fig. 4 of the Smith patent, has abundance of material near the corners, h, h, which are to be sharp and square, and are already formed, while the plaintiff's blank, by reason of its rounded corners, has a deficiency of material near the points where the square corners to be formed are to be. In the efforts to make, by dies, a shackle blank, which should ultimately have sharp outside corners, the inventors, in succession, had the idea of a reservoir or surplus of metal. ”

“ A history of the state of the art, and of the progress of invention in making shackle blanks, will conduce to a determination of the questions involved. A carriage thill shackle is a device by which the thills of a carriage are hinged to the axle. The finished shackle is a horizontal plate, with a pair of vertical ears rising therefrom, one at each end of the back. ”

“ In Burns' dies, the body of the shackle is formed straight, while the ears are curved, the curve commencing at the plane where the ears are to be bent to form the corners, and therefore said corners are not right angled; neither is it possible for curved ears to be both on one and the same line. In Clark's dies the ears are formed straight, but were arranged on different lines, so that the edge of the blank at the side of each ear was thrown out of a vertical line, which seriously interferes with trimming off the surplus metal. ”