GB890250A - Improvements in or relating to a linear motion clutch for punch presses - Google Patents

Abstract

890,250. Hydraulic apparatus. HOUDAILLE INDUSTRIES Inc. Dec. 13, 1960, No. 42871/60. Class 69 (2). [Also in Group XXII] A clutch for a punch or nibbling press comprises a hollow piston 17 in a reciprocable cupshaped cylinder 22, chambers 26, 27 in the piston and cylinder for containing a fluid 28, and an arrangement 40 which is disposed within the cup-shaped cylinder and carried thereby and is movable to positions to effect driving and non-driving engagement between the cylinder and piston through the fluid. The piston is connected by a pin 16 to a pitman 14 on an eccentric formed on a rotatable shaft 12 and is formed with a valve seat 30 engageable by a valve plate 40 secured to a pin 48 axially movable in a member 55 connected to the closedend of the cylinder which carries a tool 25, the pin 48 and member 55 providing a lost-motion connection between the valve plate and cylinder. An armature 43 is secured to the valve plate and co-operates with a solenoid 41 which is carried by the piston and operated by hand and footoperated switches and by limit switches actuated by a cam rotated by the shaft 12. When the solenoid is de-energized, the fluid is free to flow between both chambers 26, 27 so that the movement of the piston is not transmitted to the cylinder. Energization of the solenoid as the piston moves upwardly causes the valve plate to engage the valve plate but, as the piston approaches its uppermost position, the head 52 of the pin engages a surface 60 on the member 55 to prevent further upward movement of the valve plate so that fluid from chamber 27 can flow into chamber 26. On the downward movement of the piston, the seat 30 re-engages the valve plate to prevent flow of fluid between the chambers so that the motion of the piston is transmitted to the cylinder which moves in a housing 20 against the pressure of springs 36. The limit switches actuate relays in a circuit which permits single or continuous reciprocation of the cylinder. During continuous reciprocation, the opening of the valve at the uppermost positions of the piston enables loss of fluid from the chamber 26 to be replenished by flow of fluid from chamber 27. Specification 727.087 is referred to.