Excerpt from Journal of the Franklin Institute of the State of Pennsylvania, Vol. 8: Devoted to the Mechanic Arts, Manufactures, General Science, and the Recording of American and Other Patented InventionsThe general structure of this block is like those commonly used, having fixed lips or catches on one edge, and moveable, or sliding catches on the other. The two sliding catches are forced up against the edge of the plate simultaneously by turning a key which fits on to a pinion. The teeth of this pinion act upon a sliding plate, each end of which forms a wedge, these wedges acting upon the two slid ing lips, force them Up. There is a spiral Spring Upon the shanks of the sliding slips, which force them out when relieved by turning the pinion, so as to withdraw the wedges. Some other modes of movin the wedges are described, and considered as included in the genera principle.The claim is to so much and such parts of the machinery above described, in combination, as is or may be employed by moving the moveable lips to or from the stereotype plates, at one Operation, by inclined planes, or wedges and springs, acted upon by a rack and pinion with a key, or in either of the ways mentioned, and the mov ing of the moveable lips to or from the stereotype plate at one ope ration.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.