GB1108381A - Improvements in or relating to draw benches - Google Patents

Abstract

1,108,381. Draw benches. PATENTS & INVESTMENTS Ltd. 26 Aug., 1966 [14 July, 1965], No. 29770/65. Heading B3P. A chain driven draw bench has means for disengaging the hook from the chain at the end of the drawing operation and time delay means associated with the disengaging means to cause operation of the latter after a predetermined time interval has elapsed after the workpiece, or all of the workpieces, has, or have, left the die-plate. In the machine shown in Fig. 2 the die plate is mounted on the bracket 17 and the carriage 28 is moved away from the die-plate by a chain 13. At the end of the draw the carriage is returned by a cable 52 driven by a motor 50. During the draw, the part of the workpiece between the die-plate and the carriage is supported by horizontal arms 39 which swing from the solid line position to the dotted line position as the carriage passes. The arms are mounted on vertical spindles and actuated by reciprocating cylinders 46. Each cylinder is controlled by a valve which is tripped as the carriage passes. Grippers mounted on the carriage are controlled by an aircylinder 37 and the hook is actuated by an aircylinder 30. The bracket 17 which supports the die plate is strengthened by two buttresses 20 which extend away from the bracket in the direction of drawing. At the end of the draw the workpieces are removed laterally from the bench by the return of the arms 39 to the solid line position. In order to prevent the lateral movement occurring until the trailing ends of the workpieces are clear of the buttresses 20 the hook remains in engagement with the chain for a predetermined interval of time after the last of the workpieces has left the die-plate. This is achieved by mounting a micro-switch on the bracket 17 and operating it by an arm 25, the micro-switch being connected to a time-delay relay which controls the hook cylinder. The dieplate 18, Fig. 3, is movable about a pivot 19 which is positioned in relation to the dies 21 so that when the workpieces are being drawn the plate 18 pivots clockwise and operates the arm 25. The plate is spring-biased to rotate anticlockwise. The workpieces are lubricated by oil-bath apparatus connected to sleeves 23.