Patent GB-783960-A (GB)
Title: Improvements relating to the manufacture of moulded components
Inventor: HAWKINS WALLACE GERALD
IPC: A43D8/00
Filed: 1954-02-04
Abstract: 783,960. Boot &c. stiffeners. CLARK. Ltd., C. & J. Feb. 4, 1955 [Feb. 4, 1954], No. 3304/54. Class 17(1) [Also in Group XVI] Moulded components are formed by feeding pre-cut thermoplastic impregnated blanks of fibrous and other material separately to a substantially closed chamber, subjecting the enclosed blank to high temperature and a humid atmosphere, conveying the heated blank to a position between relatively movable moulding surfaces, and supporting the blank while the conveying means is retracted and at least until the blank is clamped between the moulding surfaces. In the apparatus shown, for moulding shoe shank backers, blanks are fed singly from magazine 44, by a pneumatically operated pusher, via chamber 40 to a platform 48 in an electrically heated activating chamber 49 connected to a flash boiler. The support 130 for platform 48 is moved first to postion the backer between interchangeable moulds 66, 67, and then to within the range of suction tubes 64, and when the backer is so suspended moves back clear of the backer and then clear of the moulds. Mould 66 is then moved to press the blank between the moulds, tubes 64 retracting as springs 148 are compressed and universal mounting 144 permitting mould 66 to align with mould 67. When mould 66 recedes the moulded backer is removed from mould 67 by the spring pressed tubes 64, and when the suction is cut off the backer falls into a delivery shoot 150. A circuit for controlling the machine automatically by mechanical, pneumatic, and electrical means under control of an electropneumatic circuit is described and illustrated. The machine may be operated by setting the selector lever 25A of the control valve in " Start " position, and depressing button 27A of the start valve to commence each cycle, or may be operated automatically by setting lever 25A to the " Auto" position which introduces to the circuit a valve operated by reciprocation of platform 48. If a backer of incorrect proportions is offered, or if a backer is incorrectly placed, a plunger in a vacuum interlock cylinder, which is withdrawn if tubes 64 are sealed, projects into the path of the platform carrier and interrupts the cycle. The plunger is then retracted by manual closure of vacuum valve 70..The pressure-dwell period of the moulds is adjustable. One of the moulds, particularly the female mould, may be replaced by a thick flat surfaced rubber cushion which conforms to the shape of the male mould when pressed. Instead of heating by enclosure in a steam atmosphere, the backer may be heated by high frequency means, e.g. by clamping between opposed plate electrodes. Double or multi-ply components may be treated in the machine, the plies being previously joined together, or fed separately from seperate magazines to separate or common activator chambers and then subjected simultaneously to a common moulding operation, duplicate suction tubes being provided to hold the outer plies and temporary supports for the intermediate plies. The high temperature must be sufficient to soften the blank without adversely affecting its moulding properties, and as an example components of resin-impregnated leatherboards are heated at about 400‹C.