Patent GB-800389-A (GB)
Title: A method and apparatus for making pin strip insert units for use in fibre combing apparatus, and units made thereby
Inventor: SPISAK ANDREW ARTHUR
IPC: D01H5/14
Filed: 1956-02-23
Abstract: 800,389. Embedding pin strip inserts in plastic materials. WARNER & SWASEY CO. Feb. 23, 1956, No. 5610/56. Class 87(2). [Also in Groups IX and XI] An article comprising a plurality of metal pins 25, Fig. 16, the butt ends of which are embedded in a block B of vulcanized rubber, neoprene, "Hycar"  (Registered Trade Mark-synthetic rubber) " Plastilock " or other thermosetting material, and which article is used as an insert to form part of fibre combing apparatus, is made by clamping strips 26, Figs. 1 and 2, of rubber &c. on both sides of the butts of the assembled pins, and other strips 27 around the ends of strips 26, and moulding the strips under heat and pressure on to the butts to form the block B. Before the strips are applied the butts may be cleaned and roughened by sand-blasting, then cleaned by brushing with a solution of methyl ethyl ketone, and finally coated with a Hycar composition to ensure bonding between the metal pins and the rubber &c. The rubber is heated in the mould to cure it, and the heating may be divided into three phases, viz. a flow period of three-ninths of the total heating time at 210‹- 230‹F., a bonding period of four-ninths at 330‹-350‹F. and a setting period of two-ninths at 415‹-435‹F. The pins are initially assembled in a jig 31, Fig. 5, comprising a pair of jaws 31a, 33, the upper jaw 33 being pressed down on the pins by toggles and clamping posts 40, 35. The pin butts project sideways out of the jig, and the rubber strips are folded about the butts. The jig is then clamped in the moulding apparatus shown in Fig. 6, the wrapped butts projecting downwardly into a moulding cavity formed between a stationary jaw 43 (see also Figs. 11 and 12), a movable jaw 50, a movable base 87 and two movable end jaws 80, Figs. 8B and 10. Then a shaft 68 is turned by means of a wrench whereby a toggle 67, 66 is straightened to the Fig. 7 position, thereby moving a crosshead 58, springs 59 and rods 49 to the right to close the jaw 50 from the open position shown in Fig. 11  to the closed position shown in Fig. 12. As the jaw moves, a cam 89a moving therewith raises the mould base 87 and a spring 86, Fig. 9, rocks levers 82 about pivots 83 to move the jaws 80 inwardly to complete the mould cavity (the levers having previously been restrained by pawls 78). The jaws are heated by electrical units 111 and cooled by water passing through conduits 102, and incorporate thermostats 108. Fig. 14 shows an electrically-controlled heating and cooling system. The heaters 111 are initially energized, to pre-heat the jaws 43, 50, by closing a manual switch 121 to energise a coil 122 and close switch 123, the main circuit being 112, 123, 124, 109, heaters 125, 126, 113. There is an alternative circuit through line 128, relay coil 134, line 136, switch 135, line 132, heaters &c., but this circuit is in abeyance for the time being because the resistance of coil 134 is much greater than that of the heating units. Then, switch 121 being open, a clock 116 is started to turn a cam 117 having three lobes. The first lobe closes switch 118 to energize coil 122 and energize the heaters for the flow period, and then leaves switch 118, which opens. The second lobe repeats this procedure, the temperature of the jaws rising to the bonding temperature. The third lobe also repeats the procedure, but does not allow switch 118 to open, and the temperature reaches a maximum, whereupon a thermostatic switch 109 opens, thus breaking the heater circuit at that switch ; but the heaters are still momentarily energized through the alternative circuit. However, as soon as the main heater circuit is broken, coil 134 is energized to move its relay, whereupon switches 126 and 135 are opened and switches 131 and 138 are closed. Opening of switch 126 breaks the heater circuit. Closing of switch 131 energizes solenoid 130 to open a valve to allow water to flow through the cooling conduits 102. Closed switch 138 maintains a hold-in circuit for coil 134. The third lobe of the cam holds switch 118 closed until cooling is complete. In a modified procedure a plurality of the devices shown are mounted on a turntable and the jaws are opened and closed automatically by cams acting on rollers 70a, Fig. 6, mounted on an arm 70 fixed to shaft 68.