Patent GB-1105060-A (GB)
Title: Improvements in or relating to shear machines
IPC: B23D15/14
Filed: 1965-12-07
Abstract: 1,105,060. Shearing. PACIFIC PRESS & SHEAR CORPORATION. 7 Dec., 1965 [28 June, 1965], No. 51824/65. Heading B3W. In a reciprocating shear the movable tool carrier comprises a plate 33, on which the movable tool 31 is mounted, and which has two rearward extensions 35 terminating in bearing surfaces 37 which form an angle with the plate 33. The tool carrier is reciprocated in a direction parallel to the plane of the guide surfaces by two series-connected hydraulic cylinders, one at each side of the frame, which act in a direction parallel to the plate 33 so that a horizontal component of the force applied to the ram resists the tendency of the tool 31 to move away from the stationary tool 21 during the shearing operation. The actuating cylinders are anchored to the lower part of the frame by means which includes spherical washers which allow the cylinder to tilt slightly as the assembly of cylinder (91), Fig. 5 (not shown), piston (97) and piston rod (99) shortens during the cutting stroke. The piston rods (99) are connected to the plate 33 by similar means which includes spherical washers 83, 85. The bearing surfaces 37 are supported by rollers 49 mounted in brackets 45. The lower roller is mounted on an eccentric shaft 53, so that by rotating the shaft the clearance between the tools 21 and 31 can be adjusted to suit work of various thicknesses. The bearing surfaces 37 are held in engagement with the rollers 49 by compression springs 65 which abut at one end on brackets 61 secured to the side walls of the shear and at the other end against collars 69 mounted on rods 63 which are pivotally attached to the extensions 35. The horizontal component of thrust developed due to the inclination of the actuating cylinders is insufficient to overcome the force of the springs. Lateral movement of the carrier is prevented by the engagement of rollers 113, mounted on the carrier, with guide surfaces 111 secured to the inner surfaces of the side members of the shear frame. To correct slight deviations from straightness of the movable tool 31 there are provided two spaced parallel rigid plates 141, 143 extending between the two rearward extensions 35. At spaced intervals, between the plates, are bolts 145 which are anchored at one end in the carrier and which have an adjusting nut 147 at the other end. By adjusting these nuts slight deviations in the separation between the tools 21 and 31 can be corrected. The work to be sheared is clamped to the table 15 of the shear by an air inflatable tube 121 which is secured by adhesive to a backing member 123. There are apertures (129), Fig. 1 (not shown), in the backing member, through which the work can be seen. The movable tool 31 is mounted at a rake angle to the stationary tool 21 and this rake angle can be altered, either while the shear is stationary or is operating, by two valves which are connected to the line 197 joining the lower side of one cylinder (77), Fig. 9 (not shown), to the upper side of the other cylinder (75). One of the valves when actuated allows fluid to escape from the line (197) so that the rake angle is increased and the other connects the line directly to the output of an hydraulic pump so that fluid is forced into the line and the rake angle is decreased. The valves are solenoid operated and are controlled by a foot switch.