Patent GB-683568-A (GB)
Title: Improvements in or relating to a machine for cutting paper and like material
Inventor: SPILLER WILLIAM RAYMOND
IPC: B26D1/08
Filed: 1950-08-29
Abstract: 683,568. Cutting-machines. HARRIS-SEYBOLD CO. Aug. 29, 1950. No. 21319/50. Class 31 (i). A machine for cutting paper comprises a work table 20, Figs. 2 and 6, a knife 42 which is reciprocable in a cycle including a cutting stroke and return, a clamp 150 for clamping the work on the table, hydraulic means for raising and lowering the clamp, and means for controlling the hydraulic means in co-ordinated relation with the knife cycle to maintain a predetermined clamping pressure on the work during the entire time in which the knife is in contact with the work. The machine comprises side members 12, 14 supporting the table 20 which at its rear end rests upon adjustable legs 23, 24. The knife 42 is connected to a bar 40, Fig. 2, which at each end travels between spaced guides 30, 32 connected at their upper ends by a bar 36. The opposite ends of the bar 40 are connected by adjustable links 50, 60 to bell-cranks 53, 63 which are linked together by a bar 68 and driven by a crank plate 81 and connecting rod 75. The crank plate 81 is driven through gearing &c., from a motor 94, Fig. 6, and the drive includes a clutch which is operable by a hand-lever 110 adapted to be swung downwardly to permit the drive and upwardly to apply a brake. The lever 110, which is carried on blocks 112, Fig.11, slidably keyed on a shaft 111, can only be swung downwardly to permit the drive after it has been moved along the shaft out of engagement with a locking pin. When the handle is so swung, it acts to disengage a locking member 121 from a notch 125 in the crank plate 81, and, at the end of one cycle of the knife, a cam 128 on a driven gear 84 rigid with the crank plate operates a plunger 123 so as to restore the member 121 to locking position and return the handle 110 to clutch-disengaging and brakeapplying position. The clamp comprises a narrow bar 150 mounted for vertical reciprocation immediately to the rear of the knife 42 in guideways in the members 30, 32. The bar is operated by vertical arms 151, 152, Fig. 8, connected by links 153, 154 to bell-cranks 157, 158 ; the bell-cranks are connected by a link 160, and the drive is from a hydraulic cylinder 165, the piston rod of which is connected by a link 162 to the bellcrank 158. The work-feeding gauge 200, Fig. 6 and 13, which may be formed in separate sections secured together by bolts 203, 204 permitting relative forward or rearward adjustment of the sections, has forwardly-extending fingers 207 for interfitting with fingers 208 at the rear of the clamp. Movement of the gauge to and from the knife is effected by a lug depending from the gauge through a slot 210 in the table 20 and engaged underneath the table by a screwed shaft 214 which is rotatable either by a beltdrive 216 from a reversible hydraulic motor 220 or a hand-wheel 222. The motor 220 is controlled by a valve 240 operable by a hand-lever 243 to cause movement of the gauge in either direction. Cams 250, 256 on the gauge cooperate, respectively, with bell-cranks 252, 258 acting through a control rod 248 to restore lever 243 and the valve 240 to the inoperative position at each end of the stroke of the gauge. When the lever 243 is moved in the direction to cause the gauge to move rearwardly, the rod 248 engages a latch 265 whereby the valve 240 is held in position for such rearward drive, even though the handle be released, until the gauge contacts a limit switch so as to energise a solenoid 270 and withdraw the latch. An upright 225, Fig. 6, on the gauge is connected at its upper end to an endless tape 226 which, as, the gauge is moved, travels around a pulley 227 on a rear post 228 and two pulleys at the front of the machine; the tape is graduated and, between the front pulleys, moves over a fixed index so as to permit accurate setting of the gauge. The hydraulic circuit for operating the clamp and gauge comprises a liquid reservoir 300, Fig. 18, continuously-operating pump 304, balanced relief valve 306, direction valve 330 which can be set to discharge liquid to either end of the clamp-operating cylinder 165, and the hand-operated valve 240 for controlling the gauge. A pilot valve 315 controls the valve 306 and may be set to any of three positions corresponding to the passage of no liquid, liquid at pre-determined maximum pressure and liquid at any intermediate pressure determined by the adjustment of a valve 325 disposed between the valve 315 and reservoir 300. The energization of a solenoid 402, Figs. 23 and 25, by depressing a push-button acts through a bell-crank 404 upon the control arm 407 of the pilot valve 315 whereby the valve 306 is set to deliver liquid at maximum pressure through the valve 330 to the lower end of the cylinder 165. The handle 110, Figs. 6, 11 and 25, is then unlatched and swung downwardly so as to start the cutting cycle of the knife and also act through a rod 426 to swing counterclockwise a three-armed lever 430, 440, 450 pivoted at 431. A pin 436 on the end of a rod 434 on the arm 430 is then pushed upwardly into locking engagement with the control rod 248 of the gauge whereby the latter cannot be operated. The arm 440 also disengages a spring- pressed latch 414 from its interlock with a notch 416 in the link 160 of the clamp-operating mechanism. In addition, the arm 450 acts through a rod and lever mechanism 452, 454, 456 upon a member 457 which (a) actuates the stem 336 of the -direction, valve 330, Fig. 18, so that liquid is supplied to the upper end, and exhausted from the lower end, of the clampoperating cylinder 165, and (b) moves the control arm 407 of the pilot valve 315 so as to set the valve 306 for delivery at the intermediate pressure set by the valve 325. The clamp then moves in advance of the knife to its operative position at a speed determined by the adjustment of a' valve 350 in the exhaust line from the cylinder 165, and, at the same time, additional liquid passes to the upper end of the cylinder directly from the reservoir 300 through a pipe 370 and non-return valve 372. When the clamp is fully lowered, liquid no longer passes through the pipe 370, but the cylinder space is filled with liquid at the clamping pressure determined by the valve 325. Clamping pressure is maintained-until the knife completes its cycle, which is stopped by the handle being automatically lifted by the action of the cam 128, Fig. 11. Upon this upward movement of the handle, the three-armed lever is restored to its initial position so, that (a) the arm 430 withdraws the work-gauge locking pin 436, (b) the arm 440 permits the latch 414 to return towards its locking position in relation to the link 160, and (c) the arm 450 acts through the member 457 to set the valve 306 for the delivery of liquid at maximum pressure and the direction valve 330 for the supply of this liquid to the lower end of the cylinder 165 so that the clamp is rapidly raised. At. the end of the upward movement of the clamp, the notch 416 in the link 160 is in position for engagement by the latch 414, and a latch-locking pin 412 also becomes effective. This pin, which was withdrawn from operative position at the start of the cycle by the temporary energization of a solenoid and rode up on to the upper surface of the latch when the latter was disengaged from the link 160, then opens a holding circuit, causing the solenoid 402 to be de-energized, whereby the pilot valve 315 returns to its initial setting in which no liquid is supplied by the valve 306. The work gauge is operable under the control of the hand-lever 243 when the locking pin 436, Fig. 25, is disengaged from the rod 248. The maximum operating pressure is provided in the hydraulic circuit for operation of the workgauge by arranging that, when the rod 248 is moved from its normal position as a result of the actuation of the hand-lever 243, a cam on the rod closes a switch in circuit with the solenoid 402 so that the bell-crank 404 sets the pilot valve 315 accordingly. When it is desired to provide the knife with a jogging cut by operating the handle 110 without releasing the clamp, a cam 473, Fig. 23, operates through a follower rod 470 upon the member 457 to maintain the direction valve 330 in pressure-applying direction. The clamp may be operated independently of the knife by depressing a treadle 480, Fig. 25, against spring 482 so as to act through a rod 485 upon the three-armed lever 430, 440, 450. The handle 110 and push-button for controlling the solenoid are spaced apart so as to necessitate the use by the operator of both hands in operating the machine. Specification 566,754 is referred to.