Patent GB-741846-A (GB)
Title: Improvements in or relating to a mechanism for cutting sheet material such as paper and similar material
Inventor: SPILLER WILLIAM RAYMOND
IPC: B26D7/01
Filed: 1953-06-16
Abstract: 741,846. Cutting-machines. HARRIS-SEYBOLD CO. June 16, 1953, No. 16545/53. Class 31 (1). A paper cutting machine comprises a work-feeding bar 40, Fig. 3, movable along a work table 12, hydraulic means for actuating it on a work-advancing stroke, and means for controlling the actuating means so as to cause a gradual retardation of the work-advancing stroke of the bar at a controlled rate. The gauge is moved by an arm 41 which projects through a longitudinal slot 42 in the table and is operated by a nut- and - screw engagement with a shaft 46 rotated through a belt-and-pulley drive 48 from a hydraulic motor 50. The direction of movement of the gauge is controlled by a valve 54 arranged in the hydraulic line to the motor and operable by either of two solenoids 64, 65 according to whether forward or reverse movement of the gauge is required. The rate of travel of the gauge is controlled by a metering valve 70 disposed in the line between the motor and valve 54 and actuated automatically from the driven shaft 46 through mechanism comprising gearing 74, 75, Fig. 4, friction drive 78 to a shaft 76, and linkage 83 connected from the latter shaft to the control arm 72 of the valve. This mechanism is so arranged that, with the direction valve 54 setting the motor for forward drive, the valve 70 is automatically actuated by the movement of the gauge itself so that the latter is uniformly retarded from high speed to a constant slow rate, and on the reverse movement of the gauge the valve 70 is immediately set to its high-speed position. The valve 70 may be set for fast forward drive by energizing a solenoid 90 which operates on the control arm 72 through a lever 92 and the linkage 83. The solenoids are actuated to control the movement of the gauge by switches arranged in a control carriage 120, Figs. 3, 11 and 12, which is slidable along a fixed transverse bar in synchronism with the movement of the gauge ; for this purpose, the gauge and carriage are connected by a cable 125 passing over pulleys on the cross-bar and a pulley 126 on the table 12. As shown in Fig. 11, the control switches are arranged in pairs (152, 153; 156, 157; and 160, 161) each associated with an actuating arm (154, 158, 162) operable by stop members mounted on the faces of an hexagonal control bar 200 rotatably mounted beneath the cross-bar 212. The control bar is mounted between a tailstock 211 and a shaft 210 which is rotated by an intermittently-energized motor 224 and is effective through a friction disc 248 to index the bar and bring selected faces thereof in turn into co-operative relation with the actuating arms 154, 158, and 162. Pins 242 are detachably inserted in the end of the bar in positions corresponding to those faces of the bar which are to exercise control and upon each energization of the motor 224 the bar is indexed until a pin is locked by a spring-pressed latch 234, Fig. 12 ; rotation of the bar cannot, however, occur until a cam 232 on a disc carried by the shaft 210 first actuates the latch to release the previously-locked pin. Each face of the bar has a longitudinal groove 201 for the detachable and adjustable reception of a rod 195 on which the stop members 270 have previously been clamped in those longitudinal positions at which the arms 154, 158, 162 are to actuate the switches as the carriage 120 moves along the cross-bar. The stop members consist of standard units which may be modified by clamping supplementary units thereto so that by selection of appropriate units the arms 154, 158, 162 are caused to actuate one or both of the related switches to achieve the desired control. The switches 152, 153, 156, 157, 160, 161, solenoids 64, 65, 90, motor 224 and various control relays and switches are arranged in a control circuit which can be set for either manual control or performance of an automatic cycle. In the latter case, the forward solenoid 64 and fast solenoid 90 are automatically energized after each cutting stroke of the knife by the closure of a switch actuated by the knife-reciprocating mechanism so that the gauge moves forwardly at high speed. When the arm 154 contacts a standard stop 270, the switches 152, 153 are actuated to de-energize the fast solenoid 90 so that the valve 70 is actuated by the linkage 83 to gradually slow down the gauge which then moves for a short distance at slow speed until the stop clears the arm and the switches are thereby operated to stop the gauge. After the cutting stroke of the knife, which is initiated by the operator, the gauge is automatically re-started in forward direction at high speed. When, however, a trim-out cut is to follow this cut at a small distance, a modified stop is employed for actuating the switches in such a way that the gauge re-starts at slow speed and then stops in correct position for the trim cut. A forward limit stop in the form of a modified standard unit causes the arm 158 to actuate the switch 156 to initiate return of the gauge at high speed without indexing the control bar 200 so that the same control pattern may be repeated on the next foward stroke ; by using a modified form of this stop, both switches 156, 157 may be actuated so that high-speed return is accompanied by energization of the motor 224 to set a new control face of the bar 200 into position for the next forward stroke. Similarly, a rear limit stop which co-operates with the arm 162 for stopping the gauge at the end of its return stroke may be modified to provide for automatically re-starting the gauge on a further forward stroke. The arm 154 is carried on a universal mounting which, when it engages a stop on the return movement, enables it to swing without actuating the switches 152, 153. Travel of the gauge beyond safe limits is prevented by mounting safety switches beyond the normal limits of travel of the carriage 120 for co-operation with the arms 158, 162. A direct reading of the movements of the gauge is given on a scale 145, Fig. 11, mounted beneath the cross-bar 121 and co-operating with a housing 147 which is carried by the carriage and mounts a pointer 149 and magnifying lens 148. When the control circuit is set for manual control, the machine may be operated by depressing push buttons providing for fast and slow forward movements of the gauge, fast return, and a new setting of the control bar 200. For trimming a pile of sheets on its four sides and then further subdividing it, stop units are provided on three control faces of the bar 200. The operator first positions one side of the pile against the gauge which then moves forwardly to position the opposite side of the pile for the first cut ; after this cut, the gauge automatically moves forward for the next cut, the operator having meanwhile swung the pile around through a right-angle. The other sides of the pile are similarly cut and the trimmed pile subdivided into two parts under the control of the next control face of the bar 200, the standard and forward and rear limit stops having been effective as described above. The third control face then operates to further subdivide the pile and provide a trim-out cut.