Improvements in connection with Hydraulic Shearing and like Presses.

摘要

118,518. Stewart & Co., D., and Holmes, T. E. Nov. 16, 1917. Shearing.-An hydraulically-operated shearing- press or the like of the kind in which the work is carried by a rising and falling table is constructed so that the table is lowered, not by the pressure on the work, but by a mechanical connexion with a moving member of the press. A lost-motion device forms part of this connexion to enable the shearing-blade to be moved relatively to the work. A clutch is also provided between this mechanical connexion and the table-lowering gear, this clutch being controlled by a ram operated by a cylinder in communication with the main ram of the press. As shown, the work-table B is supported by adjustable arms A3 of a parallel-motion link system comprising lever arms A2, A5 connected by links A' all controlled from a shaft A, which is connected by a link C to a counterbalancing hydraulic ram C1 in a cylinder C2. The shaft A is rocked to lower the table B by means of a link D7 connected to the moving head D8 of the press and operating a lever D4 on a counterbalanced shaft D5 by means of a slot D6, and a pin on the lever D4. The shaft D5 transmits motion by means of a link D3 and a freely-mounted clutch element D1, Fig. 2, to the shaft A, the movable element D2 of the clutch being operated to close the clutch by a lever E operated by a ram E4 of a cylinder E5 supplied from the main intensifier supply to the press through a pipe E8 and non- return valve E7. When it is required to hold the table in its lowered position for a certain time, the pressure is maintained in the cylinder E5 until the main hand-lever of the machine reaches a predetermined position, whereupon it is caused to operate by means of a link G3, lever G4, and link G5, a valve G1 which connects the cylinder E5 to exhaust, the clutch D', D2 being then unclutched and a valve H opened by means of a link and lever system H2, H3 with a lost motion. The valve H admits water from the accumulator to the cylinder C2 and thereby raises the table to normal position.