Patent GB-766956-A (GB)
Title: Apparatus for the formation of footwear
IPC: B29C35/00
Filed: 1955-02-04
Abstract: 766,956. Shoe moulding presses. CANAT, C. Feb. 4, 1955 [Oct. 25, 1954], No. 3422/55. Class 87(2). The horizontally moving sides and vertically moving base of a mould for vulcanizing footwear, and the shape carrying the leg part of the footwear, are all operated hydraulically, under the control of a single valve, and the hydraulic jack which moves the shape is rotatable and automatically turns it to the front on reaching a certain level above the table of the moulding machine. The sides 6, 6<SP>1</SP> of the mould are carried by jaws 5, 5<SP>1</SP> which are moved together or apart by hydraulic cylinders 4, 4<SP>1</SP>, Fig. 2. The bottom 10 of the mould is raised and lowered by a hydraulic cylinder 11. The last 14, on which is carried the upper or leg of the boot on which the sole is to be vulcanized, is raised and lowered by a hydraulic cylinder 12 mounted at the upper part of arms 3, 3<SP>1</SP> on a pivot 21, Fig. 3, which has a bore 26 for passage of the hydraulic fluid. The piston of the hydraulic cylinder 12 is connected to the last 14 through a member 13 which, in the lower part of its travel, moves in slides 32 and carries racks 35 which, when the member 13 approaches the top .of its travel, engages fixed pinions 22 with the result that the last is turned to the front of the machine to facilitate changing the upper. The hydraulic circuits through which fluid is supplied to, or conducted from, the above cylinders are controlled by a slide valve 38, Fig. 7, the piston rod 46 of which is extended and is connected to a rack 42, Fig. 10. The rack 42 is moved by the rotation of a pinion 41, the shaft 40 of which is turned by a knob 39, Fig. 8. The knob has four positions, and may be locked in the two intermediate positions by a stud 53 which may engage in either of two blind holes, e.g. 54, formed in the wall of the arm 3<SP>1</SP> on which the knob is mounted, Fig. 2. In the locked positions (II and III) the knob is nearer the wall and a spring-loaded base 39a engages one of two blind holes 40a in the shaft. In the extreme, unlocked positions (I and IV) the ball 39a engages the other hole 40a. When the knob 39 is in position I it does not lock the shaft 40 against rotation and the rack 42 is drawn upwards by a spring 43, Fig. 10, and the pistons 56, 57 in the slide valve 38 are in the position where hydraulic fluid is supplied by a pump 37 to the ends of the cylinders 4, 4<SP>1</SP>, 8 and 12 from which it forces the pistons so that the mould sides 6, 6<SP>1</SP> are separated, the bottom 10 is lowered and the last 14 in the position for changing the upper. This is the position of the valve shown in Fig. 7, in which the flow of the fluid to and from the cylinders is shown by the arrows. When the knob is turned to position II the shaft 40 and pinion 41 are rotated to move the rack 42 and piston rod 46 so that the pistons allow fluid under pressure to flow into the other ends of the cylinders 4, 4<SP>1</SP> and to flow out from the ends which were previously connected to the high pressure supply. The mould sides 6, 6<SP>1</SP> are thus brought to their innermost position and the raw material for the sole in granular form, is then placed in the mould cavity. The knob 39 is then turned to the position III and moves the rack 42 to cause the piston rod 46 to take up the position shown in Fig. 13, when high pressure fluid forces down the piston of the cylinder 12 with the result that the last, carrying the upper, is first turned to the vertical position and then descends until stopped by adjusting abutment screws 34, in the position shown chain-dotted in Fig. 3. At this, the hydraulic pressure rises in the piping system 83, valve passage 82 and the whole supply circuit until it reaches a valve sufficient to overcome the spring holding a ball valve 88 on its seating and the valve opens a passage through a passage 86 and high pressure fluid flows through a pipe 89 and forces up the piston in the cylinder 84, so raising the bottom 10 of the mould and pressing the moulding material against the upper. Vulcanization of the material in the closed mould is started by moving the knob 39 to its position IV. This movement causes a finger 47 on the rack 42 to close a switch 49 which closes the circuit of a timing device 50 which, in its turn, energises a solenoid 60, thereby attracting a blade 59 on the end of the rod 46 which is held so that the mould remains closed during vulcanization. The rod 46 is connected to the rack 42 by a slot 44 therein, and the spring 43 therefore moves the rack back again and the switch 49 opens. After the time required for vulcanization the timing device opens the circuit of the electromagnet 60 which frees the blade 59 and releases the rod 46 and rack 42, when the spring 43 returns the pistons in the valve 38 to their original position. The pipe connections to the hydraulic cylinders are such that high pressure fluid reaches the ends of the cylinders 4, 4<SP>1</SP> such that the sides 6, 6<SP>1</SP> of the mould open, the passages by which fluid leaves the other ends of the cylinders being clear, but the exhaust ends of the cylinders 8 and 12 are connected through the pipes 89, 83 which terminate in the passages 86, 82 which are blocked by the ball valves 85, 80. When the sides 6, 6<SP>1</SP> are fully open the pressure in the return circuit increases and overcomes the spring of the ball 80 which opens the exhaust passage from the cylinder 12, the piston of which is then able to rise and withdraw the last, carrying the moulded boot, from the mould. When the piston of the cylinder 12 has reached the end of its travel the pressure in the return circuit rises still more and is sufficient to overcome the stronger spring of the ball 85 which thus opens the exhaust passage from the cylinder 8 and the mould bottom 10 is lowered. On further rise of hydraulic pressure the fluid is directed into a by-pass circuit 90 by a flap valve (not shown). Instead of granular material e.g. rubber, being placed in the open mould, other plastic material may be injected into the mould when it is closed.