GB655525A - Improvements in method of making liquid filled golf ball cores and other rubber shells - Google Patents

Abstract

655,525. Making golf-ball cores and other rubber shells. UNITED STATES RUBBER CO. Nov. 22, 1948, No. 30285. Convention date, May 1, 1948. [Class 87 (ii)] [Also in Group XV] Rubber shells such as liquid-filled golf-ball cores are formed by making an envelope from two rubber sheets, filling it with a predetermined quantity of liquid such as boiled water, sealing the envelope after excluding air therefrom and pressing the filled envelope between a pair of dies having one or more pairs of mould cavities, thus producing a number of filled shells joined by webs. The shells may be removed from the webs, vulcanized in moulds and if necessary cut open and emptied of liquid. As described, sheets of raw rubber 11, 13 with anti-tack material such as sugar on one or both opposed faces are taken from rolls and fed between dies 151, 17 which press the sheets together round the edges of the dies, except at one point to provide a filling aperture. The formed envelope is simultaneously cut from the rest of the sheets 11, 13 by means of the knife-edge 20. The envelope 23 is then supported in a vertical position on a stand 25 and a measured quantity of liquid introduced from a funnel 28. A hinged plate 30 is raised to squeeze out air and a sealing-bar 31 pressed across the filling opening to seal the envelope. The envelope is then heated in a water-bath and placed between moulding dies 39, 40 in a press, the dies having a number of pairs of hemi-spherical co-operating cavities 46, 47. The die 40 has rollers 43 running in guides 44 in the press so that it can be readily removed therefrom. Pockets 59 are formed in its upper surface to accommodate cutters 60 on a die-plate 45 fixed in the press. Dowels 48 align the various die-plates. With the filled envelope between the dies 39, 40, the press is closed by a hydraulic piston 41 and the liquid and rubber sheet forced into the cavities, the two sides of the envelope being sealed together in the spaces between the cavities. The press is then opened, the die-plate 40 removed, and the press again closed to cause the cutters to blank out the formed shells. These are then removed to vulcanizing moulds for curing. The cutters 60 are so shaped as to squeeze the rubber adjacent the edges of the cavities to strengthen the seal at these places. The dies 46, 47 have vent-holes 52 to prevent trapping of air therein when the press is closed and have passages 53, 54 for cooling liquid. If the shells are for medical bulbs &c. they are cut after vulcanizing and emptied of liquid. The Specification as open to inspection under Sect. 91 states that the shells may be made from material other than rubber, sheets of which will bond together under pressure, and refers to making shells of rounded but non-spherical shape. This subject-matter does not appear in the Specification as accepted.