Patent GB-611993-A (GB)
Title: Improvements in or relating to the filling of shoe-bottom cavities
IPC: A43D25/14
Filed: 1946-06-06
Abstract: 611,993. Machines for shoe bottom filling. BRITISH UNITED SHOE MACHINERY CO., Ltd., BAGSHAW, C. M., CHOICE, F. C., and PRATT, J. W. June 6, 1946, No. 17141. [Class 17(i)] A shoe bottom filling machine comprises a matrix device which bridges the cavity in a shoe bottom and engages the marginal portions of the shoe surrounding the cavity and through which filling material is extruded by a reciprocating plunger operating in a rotating drum containing filling material, and shoe supporting means for pressing the shoe against the matrix device in timed relation with the cavity filling operation, with means under the control of the operator for stopping this operation. The matrix device has a platelike member to bridge the shoe cavity, consisting of a plurality of separate portions backed by supporting members allowing its margin to yield to engage the margin of the cavity, whilst its mid portion is held against appreciable movement. The reciprocating plunger moves at a lower speed when expelling the material than at other times, such as when surplus filling material is being diverted back into the drum. The shoe supporting means consist of two pads 93, Fig. 1, slidably mounted on a crossbar 89 and capable of being moved together by a treadle 108 and links 99, 101, 105, 107, 109 to grip the shoe and press it into contact with the flexible base 7, Fig. 3, of a matrix box 5 which conforms to the shape of the shoe bottom and forms a top closure for the shoe cavity. The base 7 consists of four flexible plates free at their outer edges and interconnected and overlapping at the centre, where a hole is provided in line with a tube 11 which connects the matrix box 5 with an outlet duct 8 for the filling material 20. Spring-pressed fingers 233 pivoted to a centre block 230 bear on the base 7 to ensure that it engages the edges of the shoe cavity. Filling material is forced into the shoe bottom through the tube 11, duct 8 and a duct 17 by a plunger 19, Fig. 2. which reciprocates inside a drive 21 containing the filling material. The drum 21 is also an agitator and mixer of the filling material and comprises a cylindrical wall 22, Fig. 5, continually rotated in an anti-clockwise direction, and fixed end walls 25, 27 The duct 17 opens into the drum 21 through the wall 25, and the wall 27 supports the plunger 19 directly opposite to the duct 17. Secured to the end walls is a stirrer 31 consisting of a hollow, half-crescent-shaped member placed so that one of its walls is near and parallel to the rotating wall 22 of the drum. The flat side 36 of the stirrer ensures that the filling material is presented in front of the plunger 19, which carries a sliding sleeve 75, Fig. 2, to collect filling material as it traverses the drum. The plunger 19 slides through the sleeve 75 when it enters the duct 17 to extrude the filling material. A hopper 197, which opens into the drum 21 through the wall 27, feeds in filling material from a magazine 199 where it is softened by steam passing from a boiler 209 through holes 211. A control valve 223 allows hot water to drip into the drum 21 via a duct 221 to keep the filling material there in a fluent condition. A manually operable valve 185, Fig. 3, closes the duct 8 when the cavity is filled and diverts any remaining filling material in the duct 17 through the passage 189 back to the drum 21. The machine comprises a main driving shaft 33 carying a worm 59, Fig. 6, for driving a pair of crank discs 63 on a shaft 61, and a splined friction disc 37. A complementary disc 35 rotatable on the shaft 33 is constantly driven by a motor M and drives a gear 85 also rotatable on the shaft 33 and fast with a sprocket 39 which rotates the cylinder 22, and with the driving member of a roller clutch 88 which may be engaged with the shaft 33. The friction clutch, when engaged, is adapted to drive the shaft 33 at high speed, while the roller clutch is geared down so as to rotate at a low speed. The plunger 19 is reciprocated by means of a bell-crank lever 70, Fig. 2, pivoted at 71 and a link 67 pivoted on a crank pin 65 between the discs 63 rotated by the worm 59. The plunger moves at high speed as it commences its stroke, at low speed as it extrudes the filling material into the shoe cavity, and at high speed on its return stroke. On depressing the treadle 108, the pads 93 move together and the rearward end of the link 109, Fig. 6, moves down to tilt a bell-crank lever 137, pivoted at 140, in an anti-clockwise direction and hence move a lever 153 forwardly to pull a latchlink 147 out of engagement with a spring pressed slide 139 which controls the roller clutch 88. The slide 139 then moves upwardly and allows the roller clutch to engage and the shaft 33 rotates at the slow speed. In order to start the movement of the plunger at high speed, a three-armed lever 161 is pivoted also at 140, the arm 162 of which lies horizontally rearwardly when. the machine is at rest and carries a roll 166 projecting through a slot in the upper end portion of the slide 139. Another arm 168 is spring-urged in an anti-clockwise direction, so that when the slide 139 moves upwards, the roll follows it, and the pivot 140 thus moves rearwards, rotating a lever 133 in a clockwise direction. The lower end of the lever 133 has a screw engaging the end of a rod 121, which moves forwards as the pivot 140 moves backwards, and thereby allows the friction clutch 35, 37 to engage, to connect the shaft 33 to the high-speed drive. The roller clutch slips when the friction clutch is operative. Hence the plunger 19 starts its motion at relatively high speed. A cam 170, Fig. 6, mounted on a shaft 61, a cam lever 171 and a link 169 operate to disengage the friction clutch 35, 37, about the time when the sleeve 75 meets the wall 25, by means of one of two stops 167 on the link 169 which tilts the lever 161 in a clockwise direction so pushing the rod 121 rearwards by means of the lever 133. This ensures that the plunger moves forward slowly in the later part of its stroke. The link 169 also straightens a toggle linkage 173, 175, 177, Fig. 2, to move toothed pawls 179 to engage a rack at the back of the link 105 and move it downwards to press the shoe more firmly into contact with the matrix box 5 and lock it there during the extrusion of the filling material. Another cam 151, secured to the shaft 61, and a cam lever 150 are designed to re-engage the friction clutch 35, 37, unlock the shoe engaging pads and stop the machine. To this end, a link 191, Fig 2, is secured to a hand lever 187 which operates the extrusion valve 185, and to one arm of the cam lever 150. When the operator sees filling material overflowing from the cavity, he closes the valve 185 and so moves the cam lever 150 in a clockwise direction. The cam levers 150, 171, are loosely interconnected, and so the lever 171 also moves clockwise, and by means of the link 169 breaks the toggle linkage 173 &c. and releases the shoe pads. Also the other stop 167 on the link 169 turns the lever 161 in an anti-clockwise direction to allow the friction clutch to reengage. Steps 314 and 316 on the cam 151 move the cam lever 150 in an anti-clockwise direction and so tilt a loosely connected lever 149, to which is pivoted the latch link 147, in an anti-clockwise direction and so move the latch link 147 down to reengage the top of the slide 139 preparatory to stopping the roller clutch 88. The movement of the slide 139 due to the first step 314 moves down the roll 166 which moves the pivot 140 forwards and disengages the friction clutch 35, 37. The step 316 on the cam 151 completes the downward movement of the slide 139 to disengage the roller clutch and hence stop the machine. Movement of the cam lever 150 in an anticlockwise direction also repositions the valve 185 for the next filling operation. With the construction of machine described, the cavity in a small shoe may be filled before the cam lever 171 is clear of the cam 170 and hence before it is possible to close the valve 185. A modification is described which allows the valve 185 to be closed and the shaft 33 to continue rotating until the cam 170 is closed. Further, although the roller clutch ensures that the plunger moves slowly through the final parts of its stroke, the speed of the plunger varies as the crank pin 65 moves round the shaft 61 and its extruding speed may be too high when a small shoe is being treated, so that much filling material escapes from the matrix before the operator can close the valve. To overcome this disadvantage, a variable lost motion device may be inserted between the link 67 and plunger 19 which ensures that filling of the cavity corresponds to the approach of the crank pin 65 to its lowest dead centre position. Specifications 534,037, and 612,003, are referred to.