Patent GB-512731-A (GB)
Title: Improvements in or relating to machines suitable for building a heel
IPC: A43D79/00
Filed: 1938-03-17
Abstract: 512,731. Heel-building machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., BARCLAY, W. R., and BOOTHROYD, H. March 17, 1938, No. 8205. [Class 17 (i)] Relates to heel-building machines of the kind described in Specification 420,293, and consists in the provision of means for pricking the pile of lifts in the mould to guide the nails driven. A slide member arranged beneath the mould carries both a pricker plunger and a nail block. A treadle slides the member to and fro from a forward position wherein the prickers are beneath the mould to a rearward position in which the nail block is beneath the mould. Safety devices are provided whereby a starting lever of the machine cannot be actuated initially until the slide has been brought to its forward position, and whereby after the prickers have operated the starting lever cannot be actuated unless the slide is in one of its extreme positions. A treadle lever 135 is linked to a lever 127 urged clockwise by a spring 132 and moving with an arm 121 linked to a slide 73 the guides 67 of which are slightly inclined. The slide is bored to guide a plunger carrying prickers 115 and a plunger carrying nail drivers 103, the upper parts of the two bores for these plungers housing guiding members for the drivers and prickers respectively. The plunger out of line with the mould 145 rests on one of the tables 59, 63 in front of and behind a plunger 25. This plunger is actuated by cam rolls 27, 33 above and below a cam 29 on a shaft 31 driven by a one-rotation clutch. The plunger 25 carries dogs shaped to engage projections at the base of whichever upper plunger is in line with the mould. The plunger 25 has a pin 49 by which it may be raised by a lever 45 when the operator desires to see whether the driver bores have been supplied with nails. The starting handle 177 is similar to that described in the prior Specification, and is furnished with an arm 179 cooperating with a pin 215 on one of the presser carrying rods 139 as described in the prior Specification. To prevent the handle being operated initially unless the pricker plunger has been brought into line with the mould by depression of the treadle, the handle has a pin 217 co-operating with a segment 205 on an arm carried with lost motion, by the lever 127, the handle being thus prevented from moving rearwardly to engage the latch 195 until the treadle has been depressed, to its full extent. The handle is then pulled forwardly to cause the latch to clutch the shaft 31 to a constantly running pulley 35 for one rotation, the handle being returned to its rearward position by a spring 202 as soon as the machine has started, as described in the prior Specification. After power operation of the prickers, the bars 139 rise, as described in the prior Specification. Should they be allowed to move backward, a second tripping of the clutch is prevented by the pin 215 engaging an arcuate under surface of the arm 179. The treadle is then released and the stop piece 205 moves upward in front of the pin 217. When the slide has reached its rearward position a cam surface 219 of the stop piece is presented to the pin, which can thus raise the stop piece in its movement forwardly, but is prevented moving rearwardly again. After this second actuation of the handle 177 and the consequent driving of the nails, the handle 177 is again in starting position. After the nails have been driven, the heel is freed from the mould by an arm 223 contacting the head 99 of a stem screwed into the driver guide, which carries a boss 95 of heel-tread-surface shape smaller than an aperture 163 at the bottom of 'the mould. The arm 223 is secured to a shaft 39 also carrying an arm 221 provided with a pin 249 cooperating with a latch 243 pivoted to one arm of a bell crank lever 227. The arm 221 also rests on a bar 261 carrying a block 263, the bar being urged rearwardly and balanced by a spring 265. The block 263 co-operates with a block 275 secured to an arm 139. The bar 261 is pivoted to an arm 259 urged forwardly when the treadle is depressed by an arm 271 moving with the lever 127. On the first rise of the rods 139, after pricking, the block 263 is forward of the block 275, and the heel is not raised. The descent of the rods 139 in the compression of the heel prior to nail driving allows the block 263 to pass above the block 275, the spring 265 having being allowed to move the bar 261 by release of the treadle. Final rise of the rods 139, therefore frees the heel, which is completely ejected when the rod 139 engages a pin 231 as the rods are thrown back to facilitate work charging, as described in the prior Specification. The mould is supported by a bracket 149, pivoted at 147, and is urged upwardly by spring plungers housed in bosses 150 against stops which may be withdrawn by heads 151 when it is desired to swing the bracket 149 upwards for cleaning.