Patent GB-1321062-A (GB)
Title: Web moulding machines
IPC: B29C33/44
Filed: 1970-07-28
Abstract: 1321062 Sheet forming ILLINOIS TOOL WORKS Inc 28 July 1970 [28 July 1969] 36531/70 Heading B5A In a sheet forming machine, a sheet gripped at its upper edge by a series of clamps carried by an endless chain, is passed between radiant heaters and fed to a moulding station comprising a series of pairs of mould parts horizontally reciprocable into co-operation with each other, the parts being carried about the periphery of a horizontally disposed rotating drum. Each of the pairs of mould parts is associated with a clamping device operative to engage and remove the sheet from the clamp of the feeding chain and to carry the clamped sheet around the chain with the moulds. In the described embodiment, the heat softened sheet gripped by chain carried spring clamps (see Figs. 5, 6 and 7, not shown) is fed between mandrel 108 and female mould 118 pairs carried by a horizontal shaft 66, 68, 70, itself supported by bearings 72 on a base frame and being driven through suitable gearing 54- 60 from a motor. The mandrels 108 are reciprocated into contact with the clamped web at the desired point in the rotational cycle of the shaft by means of shafts 96 carrying at their near ends cam followers 116 which ride a suitably contoured groove 130 in a fixed cam 128 located about the shaft. The female moulds are likewise reciprocated by means of shafts 106 and a fixed cam 132 provided with a groove 134 along which the cam followers 126 ride. Located between each mandrel/mould pair is a pair of clamps 150, 152 adapted to clamp individual areas of the sheet to be drawn by the associated mandrel/mould pair. Each clamp 150 is supported by a block 154 and is pivotable about a longitudinal axis of the block by means of bell-crank 164, one arm of which carries a follower 158 which rides in a slot 160 carried by a cam 162 fixedly mounted about the shaft, and the other arm of which is connected with a rod 166 to the lower portion of the clamp. Each clamp 152 is supported upon a block 168 and is constrained, by rod 166 which is also connected to the clamp, to move with clamp 150. Clamp 152 is, moreover, reciprocable into and out of contact with clamp 150 by means of a rod 172 having a follower 172 riding in a groove 174 also formed in cam 132. In operation, the web supported by the spring clamps is engaged by each successive clamp pair, the pair, by suitable rotation of the associated belt crank brought about by the shape of slot 160, being caused to move in a striaght line coincidental with the path of the web carried by the clamps during the time that the clamp is closed. This ensures that there is no wrinkling of the web in the clamped areas. After clamping the web is moved with the moulds and mandrels which are subsequently forwarded to contact with the web to effect a plunger assisted forming operation, perhaps with vacuum assistance. After the forming, the mould and mandrels are retracted and the formed articles ejected from the moulds into a vacuum take-off tube (see Figs. 13 and 14, not shown) by a knock-out plunger associated with each mould. The scrap material of the web is gripped by the grippers of a rotating wheel (see Fig. 14, not shown) after the moulds are opened and is directed over a curved surface to a granulator for re-use.