Patent GB-745442-A (GB)
Title: Improvements in or relating to heel building machines
IPC: A43D79/00
Filed: 1953-03-31
Abstract: 745,442. Heel building machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., and POPE, J. R. March 30, 1954 [March 31, 1953], No. 8839/53. Class 17 (1). A heel building machine generally similar to that disclosed in Specification 420,293 has in addition operator-actuated, means to cause the presser pad 12 to apply initial clamping pressure to the stock of heel lifts before the power means apply additional final clamping pressure. The means for loading the fastener which is driven downwards into the stock is also modified, the height of the presser pad is adjustable, the fasteners are driven to like extents automatically despite small variations in the heights of the stocks, and the fastener driving means are adapted to yield if obstructed. The pad 12 is carried from bars 18 which may be rocked about pivot 22 on treadle lever 24 between stops 56, 58, and when in the forward position the pad may be lowered by depression of the treadle, being guided by blocks 60 in grooves 62. Handle 100 is moved to trip the one revolution clutch for the power operation of the presser, on eccentric 93 on driving shaft 4 acting through 92, 90, 86, 80 to straighten toggle 64, 68 to further depress lever 24, the spring-loaded rods 78 yielding at the predetermined loading, but handle 100 cannot be so moved until member 112, lowered when the presser is depressed through foot-plate 28 &c., operates latch 106 to free lever 97. Dashpot 52 prevents violent movement of lever 72 when the latter is returned by rods 78, and limits the return of lever 24 by springs 48, while the stock of lifts in mould 8 are pressed by the power means plunger 10 acts to drive a plurality of nails upwardly out of the nail block 7 into the stock. The single nail to be driven downwardly into the stock is fed through 138, 136 and passes via a keyway 132 in the driver bar 126 and bore 122 to rest with its head on spring poppets 140, from which it is driven by driver 128. Bar 126 is slidable in screw 14, pin 134 engaged in key 132 preventing relative rotation, and when screw 14 is rotated in frame 16 to adjust the presser pad heightwise the bar 126 is moved heightwise an equal amount relative to the grooved nut 130, thus ensuring that driver 128 is brought level with the lower surface of the presser whatever the adjustment of the latter. Driver 128 is moved heightwise through 130, 152, 158 and shaft 160 which is rotated through arm 170 and link 174 pivoted to the forked arm 190 which is pivoted on arm 18 and rocked by a roll 196 engaging face 194. Roll 196 is mounted on arm 200 of a rockable bridge lever 202, an arm 210 of which is spring urged to rest on a roll 212 mounted on plunger 10. In the forward position of the presser face 194 is inclined as in Fig. 1, when the treadle is depressed face 194 descends until it touches or is close to roll 196, and as plunger 10 rises roll 212 rocks lever 202 to raise roll 196 against face 194, thus rocking arm 190 and actuating the driver 128. Face 194 is substantially vertical when roll 196 is at its highest position, therefore the heightwise position of arm 190 will vary according to the height of the stock, but the extent to which the downwardly driven nail is driven is not varied. The driver is returned by spring 182 acting on arm 170 through sleeve 180 and pin 172, faces 198 on arm 190 engaging bars 18 to limit the movement. The heightwise position of the driver is adjusted by means of nut 176 which engages pin 172. In the modified construction shown in Fig. 6, link 174 has a head 230 and length-adjusting turnbuckle 232, and arm 234 replacing arm 170 has a roll 236 engaged in a recess 238 in head 230 and retained therein by an arm 240 pivoted to the head 230 and to an eyebolt 242 which passes through a hole in the head and is surrounded by spring 248. If driver 128 is obstructed spring 248 yields so that roll 236 leaves recess 238 while link 174 completes its downward movement. Engagement of abutment 252 on arm 251 with the end of a spring plunger 254 limits the upward movement of roll 236 if the latter is dislodged and ensures its return when link 174 returns. To permit the driver bar 126 to be removed plunger 254 is depressed so that arm 251 may be swung to prevent removal of yoke 152 from the grooved nut 130.