908 FEDERAL REPORTBR. �eette, such revolving end rosette and screw being practically one piece and revolving together. In order to prevent the screw and the rosette from being carried bodily towards the fixed jaw by the sliding of the adjustable jaw on the main bar, a noteh an long as the width of the periphery of the rosette waa eut in or out of the substance of the main bar opposite the place intended for the permanent position of the rosette, and the periphery of the rosette turned within the notch so that the edge of the rosette face nearest to the fixed jaw would catch against the edge of the notch, the angle of the notch being towards the fixed jaw. But while this Coes wrenchof 1841 had advantages, it had dif- ficulties. There was a pressure against the plate by the rosette face furthest from the fixed jaw and by the end of the screw in its bear- ing, and thus the back strain or thrust from the bite of the jaws was commuuicated through the adjustable jaw, its attachment, the screw and th« plate, to the ferrule, and so to the wooden handle, before it reached the main bar through the screw nut at the handle end. The plate and the ferrule were often broken or bent and pushed out of place and the wooden handle was split or crushed. It became desir- able, therefore, to devise a way of taking oflf this back-thrust before it could reach the plate or the ferrule and thus the wooden handle, and of bringing it against the resisting strength of the main bar itself between the plate and the fixed jaw. Taft did this by his invention of 1863. He took the Coes wrench of 1841, with its main bar, fixed jaw, adjustable jaw, attachment thereto, screw, bearing, plate, fer- rule, wooden handle, screw nut, and extension of main bar, all as they were, and, in place of one rosette, he put inthree parallel rosettes, with narrower peripheries, revolving, at right angles to the Une of motion of the adjustable jaw, in three parallel grooves in the adjacent face of the main bar, each groove bearing against both faces of its rosette, so as not only to prevent the rosette and the screw from being carried bodily towards the fixed jaw, but to cause the back-thrust to be re- ceived by the side of the groove furthest from the fixed jaw, instead of, as before, by the plate. The grooves being eut in the main bar, the baek-thrust was intercepted by them, and the plate and the fer- rule and thus the wooden handle were relieved from all liability to injury from the back-thrust, while the rosette was retained in the same relative position to the handle which it had in the Coes wrench of 1841. In the original patent of 1863 the plate and the ferrule to- gether are called the ferrule, e, and it is stated that by the new arrangement the pressure which would otherwise come on the ferrule is taken off from it, such pressure being "often so great as to break it off, ��� �
