Patent GB-716138-A (GB)
Title: Improvements in or relating to the filling of shoe-bottom cavities
Inventor: GARRATT LESLIE
IPC: A43D25/14
Filed: 1952-01-03
Abstract: 716,138. Filling shoe bottom cavities. BRITISH UNITED SHOE MACHINERY CO., Ltd. Jan. 2, 1953 [Jan. 3, 1952], No. 215/52. Addition to 611,993. Class 17(1) A machine of the type disclosed in the parent Specification is brought to rest not when the plunger and pick-up sleeve are fully retracted, as in that Specification, but when they have been again advanced. As described the machine comes to rest when the plunger has completed about two-thirds of its forward stroke, the sleeve having picked up a quantity of filling material ready for the next shoe. To reverse the plunger automatically at its extreme rearward position a block 10 on the stem 313 of the reversing valve is pivoted to a lever 14 also pivoted to a cross-shaft 435 and to rods 18, 20. Springs 30, 32 are received on the rods between heads 22, 24 and blocks 26, 28 slidable on the rods and pivoted to lever 38, 40 pinned to shaft 197. The,stem 313 is retained in its extreme positions by a lug 49 on a pivoted latch bar 48 engaging a recess 44 or 46 on block 10. Latch 48 is also pivoted to a link 56 pivoted to a lever 60, 62 fulcrummed at 64 and is urged downwardly by spring 66. Cam follower 70 on arm 62 follows cam 72 fixed on shaft 197. When the plunger is moved forward shaft 197 is rotated anti-clockwise (Fig. 1) swinging arms 38, 40 to load spring 30. At completion of this plunger stroke rise '76 depresses follower 70, rocking lever 60, 62 to lift the latch 48 clear of recess 46. Spring 30 then swings lever 14, thus moving stem 313 to reverse the directions of movement of the plunger and shaft 197, and with the follower 70 on part 74 spring 66 engages the latch 48 in recess 44. At the end of the rearward stroke of the plunger the direction of movement is again reversed in similar manner by cam part 78 and spring. 32 &c. The shoe clamping valve has an exhaust port 285, an additional exhaust port 100, an inlet port 267, a port 289 communicating with the shoe clamp cylinder, and a stem 275 with lands 277, 279, and 281. When the machine is at rest the valve is arranged as in Fig. 1 and oil from the lowcapacity pump entering at 267 is exhausted through port 100 so that no pressure is built up to move the plunger. A member 110 on stem 275 at one stage abuts the stem 363 of the speed control valve to limit the movement of stem 275. The means for controlling the speed control valve, includes a bell crank 467, 469 with a roll 473 cooperating with a cam 120. A recess 122 on the cam is so oriented with shaft 197 that when the plunger has completed about twothirds of its forward movement roll 473 is spring-urged into the recess, the valve then being so conditioned that oil from the highcapacity pump is by-passed to the exhaust line. A latching device to prevent roll 473 entering recess 120 during the reverse movement of the plunger includes a pivoted latch arm 128 having an extending portion 130 and a pin 132 which is engaged by surfaces 134, 136 on cam 120. As the plunger approaches its forward limit surface 134 moves arm 128 so that port 130 overlies arm 469 and prevents roll 473 entering recess 122, but as the rearward limit is approached surface 136 swings the latch arm clear of arm 469 to permit upward movement when the recess is opposite the roll. This movement allows the valve stem 363 to return to its initial position, where oil from the high-capacity pump passes through the valve to the exhaust line. Operation of the treadle 43 (not shown, see parent Specification) moves valve stem 275 to the left (Fig. 3) so that port 267 communicates with port 289, and oil flows to the shoe clamping means. Stem. 363 moves to a less extent, and oil from the high-capacity pump flows through the hydraulic system, so that both pumps effect shoe clamping and move the plunger. Soon afterwards valve stem 363 is moved further to the left (by cam 607, roll 447, lever 441, 439 (see parent Specification), to cut off the supply of oil from the high-capacity pump so that extrusion continues under the lowcapacity pump only. By operation of treadle 743 (see parent Specification), to terminate the filling, the cut-off valve is operated and the speed control valve returns to its intermediate position, admitting the highcapacity pump to the circuit. The stem 275 moves to the right to an intermediate position, engaging stem 363, with ports 289, 285 communicating to release the shoe clamp. During the forward movement of the plunger, roll 473 moves into recess 122, arm 469 swings anti-clockwise, and valve stem 363 moves to its initial position, allowing valve stem 275 to move to its initial position. Specification 675,040 also is referred to.