GB671886A - Drop hammers of the gravity type - Google Patents

Abstract

671,886. Drop hammers. CHAMBERSBURG ENGINEERING CO. Aug. 16, 1950 [April 7, 1950], No. 20317/50. Class 83 (iv). In a drop hammer having a fluid-pressure piston for raising the tup and controlled by a lever which is operatively connected to a valve, a member movably mounted on the lever is actuable relative to the lever into the path of travel of the tup for engagement thereby on the upward stroke to close the valve. In a machine of the type described in Specification 621,529, in which the movement of the ram is automatically controlled by the engagement of tup 7 at the top and bottom of its stroke with dogs 25, 26 on the ends of a lever 22 actuating a valve 10, a third dog member 35, which may be selectively moved into the path of the tup, is mounted on the lever 22 below the upper dog 26. The dog 35 comprises an " L "-shaped piece 43, Fig. 6, pivoted at 39 on the lever 22 and normally falling into an inoperative position, but which is projectable into the path of the tup and locked in the projected position by a sleeve 40 slidable on the lever 22. The sleeve is forced downward by pressure-fluid in a cylinder 41 on the sleeve and containing a piston 44 pivoted at 47 to the lever 22, a spring 49 between the piston and cylinder normally retaining the sleeve 40 in the raised position. In operation, the pressure-fluid is passed to the cylinder 41 through a pipe 50 from the supply line 31a by the depression of a valve 52, the dog 35 being moved into the path of the tup by the engagement of the sleeve 40 with a cam face 37a on the member 43 which is further positively locked in the projected position by a face 40a on the sleeve 40. The valve 52 is disposed on the underside of the main operating treadle 34 so that the operator may alternatively depress the treadle for normal operation of the machine or may depress the treadle and valve simultaneously to establish a shorter stroke.