This is likewise an invention of Henry C. Hart, ot New York City, who has taken measures to secure a patent. It is intended to secure sheet metal whilst being cut into circular or other form and consists of two discs, between which is secured the sheet metal. The discs receive a rotary motion from the cutters as they act upon the material. The shaft of the upper disc has springs connected to it which are operated by an eccentric, so as to force the disc to press upon the metal and bend it firmly to the lower one, or by turning the eccentric in a contrary direction, to allow the upper disc to be raised from the work.
This article was originally published with the title "Improved Clamp"