Patent GB-839445-A (GB)
Title: Improvements in apparatus for shaping and curing rubberized fabric articles
IPC: B29C35/00
Filed: 1957-12-03
Abstract: 839,445. Moulding air springs. FIRESTONE TIRE & RUBBER CO. Dec. 3, 1957 [Dec. 14, 1956], No. 37621/57. Class 87(2). A press for shaping and curing rubberized fabric articles, e.g. vehicle air springs, comprises a frame, a mould having at least three axially aligned mould sections within the frame, at least two of the mould sections being movable, means on the frame for moving the mould sections axially of each other, means adapted to be axially moved within the mould for positioning and aligning an unshaped and uncured article within the mould sections, and means for introducing shaping and curing fluids into the interior of the article within the mould sections. The frame comprises a pair of posts 28 joined at the top by a rigid cross member 30, and a mould carrier 35 is vertically slidable on the posts 28 by a piston-rod 37 in a hydraulic cylinder 38. The press described comprises two similar moulding assemblies, the description of one applying to both. The upper mould section 42, in each assembly, is fixed beneath the cross member 30. The middle mould section 44 is supported by a bracket 75 slidable on, and keyed to, a vertical shaft 72. The lower mould section 46 is fastened to the upper side of the mould carrier 35 and embodies radial passages 67 and an annular chamber 68 for the successive introduction of shaping and curing fluids to the inside of the blank (i.e. the uncured rubberized fabric article). A loading tray 82, by means of which an uncured blank is positioned within the mould sections, is supported from a vertical bar 84 bolted to a gear hub 86, which is rotatable on the bottom of the post 28. Hydraulic operation of the press, from e.g. air or oil from a source under pressure, is controlled by conventional valve means and supply of the shaping and curing fluid, e.g. steam, is controlled by a timer electrically responsive to the movements of the mould sections. A blank 15, comprising a body portion 16 (formed of plies of rubberized fabric and a rubber lining) and large and small beads 20, 21 is placed on the loading tray 82 and fluid pressure is admitted to a cylinder 90, causing its pistonrod 92 to move a lever arm 94 attached to a gear hub 74, rotation of which is transmitted through an idler gear 95 to the gear 86, causing the vertical bar 84 to swing the loading tray 82 above the lower mould section 46. The middle mould section 44 is moved out of the way because the gear 74 is fixed to the shaft 72, which therefore turns, swinging the bracket 75 to the rear of the press. The middle mould section 44, carrying a previously moulded air spring bellows, is thus brought above a delivery conveyer 96, and at this point a cylinder 104 is operated and a ram 107 descends and ejects the bellows from the mould.onto the conveyer. Mounted beneath the mould carrier 35 is a cylinder 100, the piston-rod 101 of which passes through the centre of the lower mould section 46 and has at its upper end a cap 102 on which the operator places a disc 24 (which closes the smaller opening of the bellows and contacts the vehicle road gear). The piston-rod 101 rises (the loading tray 82 having an opening 88, 89 to clear it) and the blank is raised from the loading tray with the closure disc 24 concentric with the small bead 21. The piston-rod 92 is then retracted, returning the middle mould section 44 into alignment with the other two sections and returning the empty loading tray 82. Fluid is then admitted to the cylinder 38 to raise the piston-rod 37 and mould carrier 35, with its lower mould section. The bracket 75, carrying the middle mould section 44, is raised by a piston-rod 79 actuated by a cylinder 77 clamped to the shaft 72. The large bead 20 becomes sealed between a projection 58 on the middle mould section and a surface 65 on the lower, when the mould sections meet, and pressure fluid is then introduced from the chamber 68, distending the blank, before the middle and upper mould sections meet, because of the closure disc 24. The piston-rod 101 remains extended to force the small bead 21 into sealing engagement with the upper moulding surface. When the mould sections are fully closed the piston-rod 101 has been returned to its retracted position or nearly so and the curing. fluid is introduced to vulcanize the blank.