Patent GB-624791-A (GB)
Title: Improvements in or relating to splitting, skiving or like machines
IPC: C14B1/14
Filed: 1947-02-08
Abstract: 624,791. Leather splitting. BRITISH UNITED SHOE MACHINERY CO., Ltd., and HAZELTON, G. Feb. 8, 1947, No. 3761. [Class 31 (i)] [Also in Groups XXVI and XXIX] A splitting, skiving or like machine has a knife means for feeding a workpiece to the knife, means for moving the knife to and fro lengthwise of its cutting edge and knife controlling means actuated by the workpiece as it is moved towards the knife. The arrangement is such that fluidoperating means causes the knife to travel continuously in one direction while one workpiece is being operated upon by the knife and in the opposite direction while it operates on the succeeding workpiece, the knife being started into movement before it operates on the work. As shown, it is applied to the type of machine described in Specification 244,529, [Class 31 (i)], and has two pressure rolls feeding work to a knife 1 which is held in a carrier 3 operating in a dovetail guide in a knife supporting bracket on the machine so that the knife may be oscillated parallel to the rolls. A link 75 is connected at one end to the knife carrier 3, Fig. 2, and at the other end to an actuating lever 29 pivoted on a hollow timing shaft 101, Fig. 1, an arm 83 of the lever 29 being connected to a connecting rod 93 carrying pistons operating in hydraulic vertical cylinders 85, 87, whereas in the Pro. visional Specification the cylinders are arranged transversely of the machine, one on either side thereof. From the cylinders 85, 87 lead pipes 167; 181 to a reversing and control valve 147. In order that the knife 1 does not exceed a predetermined speed, a ratchet-wheel 99 is carried on the shaft 101 which is driven at a uniform speed unidirectionally by means independent of the hydraulic operating means through a chain 106 and a wheel 105. A hydraulic pressure controlling arm 111, Fig. 4, carrying a pawl 121 is pivoted at 109 to an extension of the lever 29. Pivoted on the pawl 121 is a link 127 having at its other end a roller 133 running in a slot 135 in a bracket 137 secured to the machine. Also secured to the roller 133 is a link 129 which carries at its other end a pawl 123 on the end of a lever 125 pivoted about the shaft 101. According to the Provisional Specification, the lower pawl is connected to the pressure controlling arm and the upper pawl to a lever rotatably about the timing shaft. If the movement of the knife 1 and its lever 29 is faster than the predetermined speed, one of the pawls 121, 123 (dependent on the direction of travel of the knife) engages the ratchet-wheel 99, causing movement of the lower end 113 of the lever 111 as the pivot 109 is spring loaded to the extension of the lever 129. The end 113 of the lever 111 carries a stud 115 having a spherical head 116, Fig. 1, resting in a recess in the head 117 of a pressure controlling shaft 119 running in the shaft 101. Movement of the end 113 of the lever 111 due to interlocking of one of the pawls 121, 123 with the ratchet-wheel 99 causes a longitudinal movement of the shaft 119 and a consequential reduction of hydraulic pressure in the operating cylinders 85, 87 by a movement of a spindle 141 in the reversing and controlling valve 147, Fig. 8. The spindle 141 is urged toward the shaft 119 by a spring 143, and the spindle 141 has a shoulder 155. Movement of the spindle 141 against the action of the spring 143 causes the shoulder 155 to block the inlet pipe 151 through which fluid is supplied under pressure from a pump (not shown). The reversing valve comprises a sleeve 164 having an inner sleeve 163, Fig. 11, integral therewith within which is rotatably mounted a reversing valve spindle 161. The sleeve 163, Fig. 11, comprises U- shaped grooves 191, 199 having openings 193, 194 and 201, 202 respectively, each groove 191, 199 having recesses 203, 205 and recesses 187, 195 having holes 189, 197 therethrough. The ends I, J of the sleeve are joined as shown in Figs. 9 and 10. The spindle 161 has holes 207, 209 at right angles to each other but not interconnected at the bottom of four recesses on the spindle. With the spindle 161 in the position shown in Fig. 9, fluid under pressure flows past the shoulder 155 from the inlet pipe 151 through a passage 159 in the sleeve 164, through the holes 197 in the recess 195 of the sleeve 163, along the holes 209 in the spindle 161, through the openings 202 along the groove 199 and the recess 205 to the passage 169 through the pipe 181 to the cylinder 87. The pressure fluid also flows to the cylinder 87 through the opening 201, groove 199 and passage 169. Fluid from the cylinder 85 is exhausted through the pipe 167, the passage 165, the groove 191, the opening 194, the holes 207, the holes 189 to the exhaust pipe 185 to the inlet side of the pump and fluid also is exhausted through the passage 165, the recess 191, the passage 193, the holes 189 to the passage 183 and the pipe 185. With the spindle 161 in the position shown in Fig. 10, fluid under pressure flows through the holes 197, the holes 209, the openings 194, along the groove 191 and the recess 203 to the passage 165 and along the pipe 167 to the cylinder 85. Fluid also flows along the openings 193 and the groove 191 to the passage 165. Fluid is exhausted along the pipe 181, through the passage 169, the groove 199, the openings 201 and the holes 207, 189 to the passage 183 to the exhaust pipe 185. Fluid also exhausts along the openings 202 and through the holes 189 to the passage 183. At the end of the spindle 161 is a valve arm 213 having two lugs 215, Fig. 13, on which rest the arms of a T- shaped lever 217 on which is pivoted at 222 a latch member 223 at the other end of which is a slot 225 carrying a stud 227 secured to the lower part of the arm 213. The lower end of the latch member 223 is arranged to engage one of two recesses 231, 233 on a plate 235 secured to the valve 147. The lower end of the T-shaped lever 217 is pivotally connected to a link 229. The link 229 is adapted to move lengthwise. As the link 229 is moved to the right, as shown in Fig. 13, with the spindle 161 in the position shown in Fig. 9, it tends to turn the lever 217 about the right-hand lug 215, thereby raising the member 223 out of the recess 231, thereby turning the spindle 161 to the position shown in Fig. 10 and forcing the latch member 223 into the recess 233, by the action of a spring 219 on the lever 217. Movement of the link 229 to the right reverses the process, turning the spindle 161 back to the position shown in Fig. 9. This movement of the link 229 causes the oscillatory movement of the knife 1. The upper end of the link 229, Fig. 12, is pivoted to a triangular arm 239 pivoted at 241 to a bracket 243 on the machine. Rotatably carried on the bracket 243 is a shaft 245, Fig. 1, the left-hand end of which carries an arm 249 having a screw 251 and is resiliently urged inwardly. The screw 251 is engaged by and moved with the knife carriage 3 as it moves to the left of its stroke, as viewed from the front of the machine. This counterclockwise rotation of the shaft 245, Fig. 12, rotates an arm 253 and a link 255 rotating a vertical rod 257 clockwise about its upper pivot and the lower end of the rod 257 is moved to the left of a slot in a plate 265 secured to the arm 239. The rod 257 is reciprocated to operate the link 229 and thus to reverse the hydraulic flow to the cylinders 85, 87 by means of its upper end, Fig. 1, being pivoted at 259 to a cam arm 261 having a follower 264 running in a cam 266. This cam 266 corresponding to a cam 91 in Specification 244,529, [Class 31 (i)], is started into rotation each time -a workpiece approaches the knife by the workpiece raising a plate causing a clutch to be closed and the cam to be driven through one revolution. In a modification, a similar knife-operating mechanism could be embodied in a machine disclosed in Specification 542,657, [Class 31 (i)], wherein the measurement of a workpiece is transferred from measuring mechanism at the front of the machine to splitting mechanism at the rear thereof by hydraulic means, fluid for the measuring mechanism and for the knifeoperating mechanism being supplied from the same source of supply. A device is provided to enable the knife 1 after removal for grinding or renewal to be replaced in its previous position. A stop member 31, Fig. 5, is provided at each end of the rolls 7 and 9, extending longitudinally of the machine and comprises a face 34 against which the knife edge is positioned and has a vertical slot 35 into which projects a guiding block 37 secured to the machine frame. An adjusting screw 39 threadedly engages the member 31 and projects into the slot 35 engaging the block 37. Each member 31 has a pin 43 engaging in a slot in a lever 47 pivoted at 49 on the machine frame. The lower end of the lever 47 is pivoted to a rod 50. The rearward ends of each rod 50 are pivotally connected to a transverse bar 51. The centre of the bar 51 is universally jointed to a substantially vertical arm 53, which projects through slots in the knife-supporting bracket and connected at its upper end by a pivot 55 to the bracket. The knife carrier 3 carries a plunger 65 containing a spring-loaded rod 63. When the carrier 3 is in its mid-position having been disconnected from the actuating lever 29, the plunger 65 is aligned with an aperture in the knife-supporting bracket. On releasing a catch 71 from a retaining groove 73 on the plunger 65, the plunger is moved forward and enters the aperture in the bracket. The spring-loaded rod 63 engages a lug 61 on the arm 53 rotating it forwardly about the pivot 55, thereby pushing the membets 31 rearwardly against the action of a spring 59 normally holding the members 31 forwardly. The knife 1 can be removed by releasing retaining screws 5. On replacing the knife 1, the rod 51 pivots about the arm 53 until the knife 1 is in its previous position. To release the carrier 3 from the bracket, the plunger 65 is pulled rea