GB1321682A - Machine tool having a gauging apparatus - Google Patents

Abstract

1321682 Press brakes, gauging stops, carriage actuating device HURCO MFG CO Inc 23 June 1970 53953/72 Divided out of 1321681 Headings B3B, B3E and B3W A pair of guaging assemblies of a pressbrake' power shears or punch press, each have a stop 38 mounted on a carriage 27, Fig. 3, as described in Specification 1,321,681, the carriages being simultaneously movable towards or away from the press, punch or shears by an hydraulicpneumatic circuit as shown in Fig. 4. To move each carriage in the direction of arrow 47, a compressed air supply is connected by a valve 88 to a chamber 50B of a cylinder 44, the cylinder 44 being attached to a carriage 37 and mounted on a fixed piston rod 28. The cylinder 44 will thus move in the direction of arrow 47 and force hydraulic fluid from chamber 50F in to chamber 45B of a cylinder 44L via parallel valves 84, 86. The movement of fluid in to chamber 45B causes the cylinder 44L, attached to a carriage 37, to move in the direction of arrow 47, thus forcing fluid from chamber 45F in to a surge tank 77. Movement in the opposite direction 46 is effected by venting cylinder 50B to allow the pressure in surge tank 77 to force the cylinders 44, 44L back. The movement of the cylinders is controlled by the valves 84, 86, the closure of valve 86 causing the movement to slow and the closure of both valves causing movement to cease. Another hydraulic circuit is shown in Fig. 6 in which to drive the guages in the direction of arrow 47, a valve 236 is moved so that chambers 203 and 223 of cylinders 201 and 202 respectively are vented while air is supplied to chambers 204 and 224 and oil from chambers 209 and 227 move into chambers 228 211 respectively. As in the previous circuit movement of the carriage is controlled by valves 84 and 86. Assuming the volume of chambers 209 and 211 are slightly smaller than those of chambers 227 and 228, there will be a shortage of oil in chamber 228 and an excess in chamber 211 when the carriages are moved in the direction of arrow 47. To compensate for this an inclined plane 231 of cam 229 causes its follower to rise as the cylinder 202 is driven in the direction 47 and displaces fluid from cylinder 234 into chamber 228. The slope of the cam 229 is adjusted by screw 229A to compensate exactly for the difference between the displaced volumes. Simultaneously as cylinder 201 moves in the direction 47, the carry 217 of cam 216 causes a piston to descend in cylinder 221 increasing the volume to receive the difference in volume between chambers 227 and 221. The slope of cam 216 is adjustable by means of a screw 216A.