Patent GB-860263-A (GB)
Title: Improvements in or relating to apparatus for molding contoured and profiled areas of
IPC: A43D8/04
Filed: 1957-05-09
Abstract: 860,263. Injection moulding footwear. MODERN SHOE MAKING MACHINERY CORPORATION. May 9, 1957 [Dec. 26, 1956], No. 14789/57. Class 87(2). Apparatus for preforming a shoe-upper part comprises a mould having co-operating sections for defining the ultimate shape of a portion of the shoe-upper part, means to open and close the mould sections, means under pressure for automatically injecting a predetermined quantity of plastic material into securing engagement with the shoe-upper portion, at least one of the mould sections having a cavity, and the confronting surfaces of the mould sections surrounding the cavity co-operating for clamping the shoe-upper part therebetween. The plastic material may be thermosetting or thermoplastic, a preferred resin being polyethylene with or without fillers, e.g. wood and glass fibres or cork granules. Clamping means. In the example shown in Fig. 3, the shoe portion is clamped between two mould sections 35, 37, the section 37 being movable by a hydraulic piston 51 and cylinder 50. The spacing of the mould sections 35, 37 in the closed position can be adjusted by means of stop members 60, 65, the member 60 being threaded and having a pulley portion 62 for remote control. A pressure sensitive switch stops closing movement if the operator's fingers one placed between the mould sections during the initial forword movement of the plunger 40. This switch is cut out when a follower 71 rides up a cam 69 carried by the stop member 65. A resilient seal 76 on the mould sections 35 and/or 37 prevents leakage of the plastic material. The position of the mould relative to the injection means is adjustable by means of a threaded bolt 23 having a pulley 29 for remote control. Injection means. Plastic material is fed from a hopper 17 into a loading chamber 126. Hydraulic pressure applied through an inlet 125 moves a tubular slide 110 into enclosing engagement with a sleeve 108 to confine the plastic material within the bore 109 of the slide 110. A hydraulically operated ram 121 then advances to force the plastic material through a bore 101 to cause longitudinal downard movement of a spindle 86 to bring a hypodermic type needle 95 into the injecting position seen in Fig. 4 (not shown). In this position the bore 101 is in communication with a bore 93 in the spindle 86. After injection, the spindle 86 and needle 95 are retracted by a spring 87, and the slide 110 and ram 121 returned by hydraulic pressure applied through ports 140 and 142 respectively. " Wiping " means. Immediately after withdrawal of the needle 95, a plunger 207, Fig. 16, may be advanced to cause the lower parts of the shoe upper to be turned down by means of wiper arms 217, 218. These arms are secured to one another by a spring 219 and to a bifurcated plate 210 by springs 221, 222. The birfurcated plate 210 has a flange 208 secured to the plunger 207. Turret assembly. (Fig. 21) A turret 230 rotatable about a horizontal spindle 233 comprises a number of loading stations 231 which are brought, in turn, into a single injection position. Each station comprises two mould sections 250, 253 which are removable to enable shoes of different sizes to be treated. Mould section 250 is secured by a bolt 251 to a base section 242 which is slidably received by parallel grooved side arms of a bracket 238. A bolt 245 and stop member 244 secure the base 242 to the bracket 238 which is supported on the turret 230 by arms 237. Mould section 253 is moved by means of a piston 262, and 267 is a ram for actuating a wiping blade 270. 264 is a turret locating plunger, and 277 is a thrust resisting stop member. Plastic material is supplied to a pocket between the sides of the shoe upper by a flexible pipe 274 connected to a pressurised source 275. The pipe 274 shown is arranged for manual operation but all operations of the assembly may be electro-hydraulically controlled. Forming plastic-receiving pockets. In Fig. 11 a lining 187 is stitched at 188 to the inside of the shoe upper 75 to form a pocket to receive plastic material. A second pocket is formed by a lining 191 stitched at 192 to the toe area. In Fig. 25 an outer leather quarter 301 has a lining 303 stitched to it at 304 and a strip 207 of e.g. fibreboard disposed between the leather 301 and lining 303. The strip 307 is tapered and produces varying thickness on the plastic material which is injected by the needle 95. In a further modification the two halves of an upper are split at each end, Fig. 27 (not shown), and stitched together, Fig. 28 showing the split portions 314a, 314b of the quarters 314 stitched together at 316. Plastic material 318 is injected by a pair of needles (not shown). In another example the lining is dispensed with and the pocket formed between the outer leather and a highly polished surface of the mould member, the plastic adhering to the leather but not to the mould. In Fig. 25A two layers 326, 326a of fleece cotton doubler material are stitched together at 328 to form a pocket within a pocket and confine the plastic material, thereby leaving the top quarter inch of the upper pliable. Specification 860,264 is referred to.