Patent GB-576067-A (GB)
Title: Improvements in or relating to machines adapted for levelling shoe bottoms or for performing other pressing operations on shoe bottoms
IPC: A43D89/00
Filed: 1943-12-13
Abstract: , 576,067. Machinery safety devices. BRITISH UNITED SHOE MACHINERY CO., Ltd., WOODCOCK, R. B., and BROWN, S. Dec. 13, 1943, Nos. 20809/43 and 11260/44. [Class 80 (iv)] Consists in means for ensuring greater safety to operators of shoe bottom levelling or other shoe part pressing machines by the provision of guarding devices which prevent access to co-operating pressure-applying parts whilst in operation, and by the provision of other devices that operate temporarily to lock operator-controlled starting members, and by the provision of devices which ensure positively the stopping in separated position of co-operating pressure-applying parts when the power drive to such parts is removed. In a frame 10, Fig. 1, are mounted duplicate pairs of shoe supports 12 and pressing forms 14. The supports 12 are carried by jacks 16 pivotally mounted on a transverse shaft 18 and each connected by a link 20 to a carrier 22 for the pressing form 14, each carrier being pivoted at 24 to the frame. The jacks 16 are connected by links 26 to cranks 28, each of which is carried by a separate crank-shaft 30. Each shaft 30 is driven by a pulley 38 on a shaft 32 carrying a worm 34 engaging a worm-wheel 36 on the shaft. The pulley 38 may be connected to the shaft 32 by a friction clutch 40 by moving the pulley which has a collar groove 44 engaged by pins 46 on a lever 48 pivoted at 50, the lever being loaded by a spring 52. 'The lever is held in the position to disengage the clutch by a shoulder 54 thereon engaging a stop arm 56 pivoted at 58 to a lever 60 carried by a shaft 62. The clutch is engaged by rotating a shaft 64 carrying a cam 66 which lifts the stop arm 56. To disengage the clutch after the jack and form-carrier have returned to their forward positions, the shaft 30 carries a cam 70, the groove 72 of which receives a cam roll 74 on a bellcrank lever 76 connected by an adjustable link 80 to the lever 60. The shaft 64 is turned to lift the arm 56 and immediately returned to its original position so as to allow the arm 56 to drop at the appropriate time. The mechanism thus far described constitutes normal practice. According to the invention, each of the shafts 64 is turned to engage the clutch by a manually - operated, counterweighted lever 82 journalled on a shaft 84 in brackets 86 and connected by a link 90 to an arm 92 on the shaft 64 in such manner that downward movement of the lever causes the arm 56 to be lifted. The bracket has a forwardly-extending portion 94, Figs. 1, 2, forming a guide for the lever. An upwardlyextending arm 96 has a stop 98 to limit the upward movement of the lever, the lowermost position of which is limited by an adjustable stop 100. A guard 104 at the forward end of the lever protects the operator's hands when the lever 82 is lowered by preventing the hand from remaining on the shoe support. The guard is carried by an arm 106 journalled on a pin 108 to permit the guard to be swung to one side. To prevent the lever 82 being lowered if the guard is not in operative position, a bar 110 carried by links 112, 114 is connected to a handle 122 by which the lever 82 is actuated. If the guard is in correct position, pressure on the handle removes bar 110 from a shoulder 120 on the part 94, but if in incorrect position a cam 124 associated with pin 108 prevents movement of the bar 110. With lever 82 lowered, the bar 110 engages a curved surface 126 of part 94 and thus prevents movement of the guard to inoperative position. It may happen that an operator observes that a shoe approaching the front of the machine has received sufficient treatment and that he desires to throw that support out of operation. To do this, he lifts the control lever at that side of the machine by depressing the lever at the other side with the expectation that the shoe support will stop at its forward position, but if he is late in so doing, the stop arm 56 may not be in position to throw out the clutch and the carriers will continue to rock. To prevent, in such a case, the operator from grasping a shoe and attempt to remove it, each lever is locked in its lowermost position at a moment near the end of a cycle of operations and until the shoe support and the form have started to move well back in the next cycle. An arm 130, Figs. 1, 6, has a.projection 132 which is at one side of a pin 134 when the clutch is engaged. The pin 134 is carried by a sleeve 136 slidable in a bracket 138 on the machine frame. The sleeve has an upwardly-extending ear 140 connected by an adjustable link 142 to an arm 144 pivoted at 146 to the machine frame and carrying a cam roll 148. Near the end of a cycle, the pin 134 moves out alongside the projection 132 to lock the shaft 64. The operator must then wait until the end of the next cycle. By connecting the arms 130 by an adjustable link 152, the shafts 64 will be rocked simultaneously in opposite directions so that the levers 82 will be moved in opposite directions. If these levers be both moved to mid-position, Fig. 2, neither clutch will be engaged. Mechanism is shown in Figs. 7, 8 for positively locking shoe-supports and forms against unwanted movement when the latter are not in operation. The arms 130 on the shafts 64 have their counterparts in arms 230 which have functions and interconnections similar to those of the arms 130 with the addition of additional functions to bring about the locking. Each arm contains a cam-track 232 which actuates a roll 234 on an arm 236 of a bell-crank lever pivoted in a sleeve 238 fixed on the machine frame. The other arm 239 carries a stud 258 adapted to abut a lug 242 projecting from a sleeve 244 -pivotally and slidably mounted on the shaft 64 between collars 246, 248, the collar 248 entering a recess in the sleeve. A torsion spring 240 around the hub of the bell-crank lever has a downwardly extending part passing through a pin 241 on the lug 242. Each sleeve has an upstanding stop arm 250 adapted to enter a notch 254 in the face of a disc 252 fixed on the worm gear 36. When either shaft 64 is rocked to throw out a clutch, the cam track 232 rocks the lever 236 to cause the sleeve 244 to rotate under the load of spring 240 to bring the upper end of arm 250 into contact with the disc 252. The notch 254 is so positioned that, at the moment when the clutch is actually disengaged, the notch comes opposite the arm 250 and the latter will enter the notch to stopthe worm gear 36 and hold the shoe-support and form in their separated stopping position.. To release them and start the machine, it is only necessary to rock the appropriate-shaft 64 in the reverse direction. The arms 230 therefore perform the double function of controlling the time at which the rock-shafts 64 may be moved to disengage the clutches, and of actuating a positive stop at each side of the machine. Specification 22155/03, [Class 17], is referred to.