GB1449467A - Pallets and their manufacture - Google Patents

Abstract

1449467 Injection moulding reinforced pallets GKN SANKEY Ltd 9 May 1974 [23 March 1973 19 March 1974] 14043/73 and 10172/76 Heading B5A [Also in Division B8] In the moulding of a reinforced article (e.g. a pallet 15) in a horizontal injection moulding machine, the reinforcement (e.g. metal rods 12-14 welded into a grid, Fig. 3) is held to one of the mould halves 28 while the mould is closed by means of projections 34 which retracted after mould closing, further projections 26 being extended to locate the reinforcement during moulding. All the projections may be retracted towards the end of injection to allow the injected material to entirely cover the reinforcement. The projections 34 comprise sleeves 34a into which rods 12 of the reinforcement are fitted and are positioned by pins 34b, both the pins and the sleeves being flush with the mould surface 30 after retraction by rams 35, Fig. 4. Cores 32, 33 which form opening 17, e.g. for engagement by a fork-lift are advanced and retracted by rams (not shown), and after advancing are expanded by a wedge 38, Fig. 8. Pads 22b are provided on the sides of the cores (dotted lines on Fig. 4) or on the mould walls to produce apertures 22 in the faces of the pallet. The grooves 36, Fig. 8, on the cores form the ribs of material covering the rods 12, 13, and may alternatively be provided on the mould faces to produce ribbed surfaces on the pallet. A pallet having apertures on opposite faces which are not in register may be injection moulded in the cavities formed between the interdigiting portions 56-61 and 67-71 of mould halves 52 and 54, Fig. 12. A metal grid is held by projections 85, 86 engaging rods 46. The projections 85, 86 have tongues 87, 88 engaged within an apertured block 89 by inclined teeth 90 which is movable by rod 92 to advance and retract the projections 85, 86. A cover plate 93 on the apertured block 89 engages a recess in the opposing mould face. Projections 95-100 are advanced to hold other parts of the reinforcing grid during moulding.