GB640605A - Improvements in and relating to machines for bending sheets or plates of metal - Google Patents

Abstract

640,605. Angular bending. RHODES, C. J. April 30, 1948, No. 11947. Addition to 556,836. [Class 83 (iv)] The mechanism employed in the parent Specification for cutting or shearing metal sheets or plates is applied to the operation of the beam 5 of a bending machine for bending sheets or plates of metal. The beam 5 is raised and lowered equally near each end by links 12 connected to levers 14 rocking about fixed pivots 15 and connected by links 17 to a common rod 20 which runs parallel to the beam and is slidable in either longitudinal direction in fixed guides by hydraulic means associated with pedal or hand-operated control mechanism. The beam 5 carries a bending tool 4 which is adjustable in relation thereto by worm gears on a shaft 8 driven by a motor 10. A fixed bending tool 3 is provided on the bed 2 of the machine and disposed beneath the tool 4. A double-acting piston 21 actuated by oilpressure in a cylinder 22 is attached to the end of the rod 20, which, when moved to the left as viewed in Figs. 1 and 4, acts through the links 12, 17 and levers 14 to feed the beam 5 in the downward direction. Oil is drawn from a reservoir 37 through filters 39 and supplied by a motor-driven rotary pump 36 to the cylinder 22 by depression of one of the foot pedals 24 or a hand lever 25. The pedals 24 and lever 25 are connected by a linkage to the control slide in a distributer valve 41 which is connected to the pump 36. As the beam is moving in the downward direction, oil flows from a port 44 in the valve 41 into a port 49 in the cylinder 22, while the oil in'front of the piston is forced therefrom back to the distributer valve 41 and reservoir 37. When the beam 5 has reached the end of the down stroke, a cam thereon contacts a trip lever to re-set the distributer valve 41 in the up-feed direction so as to reverse the direction of flow of the oil. The piston 21 moves to the right until the beam reaches the highest point in its travel, when the piston uncovers a port 48 and allows the oil to exhaust therethrough to. a return valve 55, into the valve 41 through the port 44 and out through a port 45 to the reservoir. The cylinder is provided with a draining valve 54 and a valve 53 to allow air bubbles to escape.