Patent GB-1223488-A (GB)
Title: Improvements in or relating to cutting presses
IPC: C14B5/00
Filed: 1968-04-16
Abstract: 1,223,488. Cutting-out presses. BRITISH UNITED SHOE MACHINERY CO. Ltd. 16 April, 1968 [20 April, 1967], No. 17914/68. Heading B4B. [Also in Divisions F1 and F2] A cutting press comprises a table 2 on which material to be cut and a superposed cutting die can be placed, a beam 4 mounted for swing- ing movement over the table between a cutting position, in which the beam overlies a cutting die placed on the table, and an out of the way position, and fluid pressure operated means for effecting both heightwise movement of the beam towards and away from the table, to effect cutting and return strokes of the press, and also. swinging movement of the press between the cutting and out of the way positions. The beam 4 is mounted on a pillar 5. The fluid pressure operated means includes a piston and cylinder 8, 10 for effecting cutting and return strokes of the press and traverse means 7 connected to the return stroke side of the piston and cylinder 8, 10. The traverse means 7 comprises a rotary piston arrangement secured to the pillar 5, the rotary piston arrangement comprising a ring 18, Fig. 2, to the inner face of which is secured a member 22, another member 21 being secured to a drive-shaft 20 which is connected to the pillar 5 in such a manner that relative axial movement can be effected therebetween but not relative rotary movement. Introduction of pressure fluid into the chambers 23 or 24 between the members 21, 22 is effective to cause the member 21 and thus the pillar to rotate. The shaft 20 is connected to the piston 10. A valve 70, Fig. 4, is arranged between the piston and cylinder 8, 10 and the traverse means 7, the valve having a first position in which it allows passage of pressure fluid from the piston and cylinder 8, 10 to the traverse means to cause swinging movement of the beam in one direction, a second position in which it allows passage of pressure fluid to the traverse means to cause swinging movement of the beam in an opposite direction and a third position in which passage of pressure fluid to the traverse means is prevented. The valve is associated with a microswitch 88 which forms part of an electrical circuit, Fig. 6 (not shown), and which is effective after operation of the valve to cause the beam to be swung from an out of the way position to a cutting position, and upon movement of the valve to its third position, to cause a cutting stroke of the press to be effected. The valve is movable between its three positions by a hand lever 85, Fig. 1. Pressure fluid is constantly applied to the cutting side of the piston 10 when the press is in use, valve means 52 being provided for controlling the passage of pressure fluid to and from the return stroke thereof. The valve means 52 is controlled, for effecting a cutting stroke of the press, by an electromagnet 58 which is energized when the valve 70 is moved to its third position. The electromagnet is de-energized upon contact being made between an insulated plate 103 carried on the beam and the table 2 through the intermediary of a cutting die placed on the table, to terminate the cutting stroke of the press. The return stroke side of the piston and cylinder 8, 10 is connected, by a spring-loaded valve, to a sump 63, 64 and 66. The valve includes a tube 33 urged downwardly by a spring 36 to abut the upper end of the shaft 20 and a block 40 mounted for heightwise movement, by means of a hand wheel 44, and engageable with a flange 41 formed on the tube 33, the arrangement being such that engagement of the block 40 and flange 41, as the beam is raised to effect a return stroke of the press, is effective to move the tube 33 out of abutment with the upper end of the shaft 20 whereby the valve is opened to the sump and the return stroke of the press is terminated. The heightwise adjustment of the block 40 relative to the beam varies the limit of the return stroke of the press. To prevent a cutting stroke being effected if an operator's hand is in the region of the beam, two springs 104 connected to earth are provided, one on each side of the beam and each closely adjacent the insulated plate 103 (see Division F2).  Reference has been directed by the Comptroller to Specification 1,060,656.