Patent GB-694649-A (GB)
Title: Improvements relating to the feeding of moulding powder and the like
IPC: B30B15/30
Filed: 1950-07-21
Abstract: 694,649. Measuring plastic moulding powder. A.C.I. PLASTICS PROPRIETARY, Ltd. July 21, 1950 [July 25, 1949]. No. 18255/50. Class 106 (v). [Also in Group V]. Measuring and feeding apparatus for plastic moulding machines comprises a horizontal table provided with a mould cavity, a feed member arranged above and movable parallel to the table, a measuring compartment, extending through the feed member from the upper surface thereof to the surface of the table, supply means arranged above the feed member at one side of the mould cavity, means operable to actuate the feed member whereby the measuring compartment is successively moved into register with the supply means to receive a measured charge of moulding powder or the like and then into register with the mould cavity to deposit the measured charge thereinto, means operable to raise and lower the feed member relatively to the table to regulate the volume of the measuring compartment and means for maintaining substantial sliding contact between the lower end of the measuring compartment and the table. As shown the moulding machine comprises a fixed horizontal table 10 in which is mounted a mould cavity 11' the bottom of which is formed by a hydraulically operated ejector head 12. A hydraulically operated male mould member 17 is arranged directly above the cavity 11'. An oscillatable vertical spindle 21 disposed adjacent the mould 11 is fitted with a sleeve 22 having an integral radial arm 22' which is provided at its outer end with a laterally projecting horizontal feed blade 23 which extends above the table 10. The sleeve 22 is slidable on a key 24 fitted to the spindle such that it is constrained to turn with the spindle but is adjustable axially thereon thus allowing the feed blade 23 to be raised and lowered relatively to the table thereby adjusting the size of the measuring compartment formed by the bush 51 and sleeve 52. Such raising and lowering of the blade 23 is effected by connecting a peripheral flange 22<SP>2</SP> of the sleeve 22 to a vertically adjustable member 25 which is restrained against rotary movement by guide pins 26 extending into holes in a fixed casing 27 but which is capable of vertical movement such movement arising from the interengagement of screw threads on the member 25 and on a nut 28. The nut, which is free to rotate but constrained against axial movement, is provided with worm teeth 28' to coact with a worm 29 fitted with an operating knob 30. Adjustment of the size of the measuring compartment by vertical adjustment of the blade 23 via actuation of the knob 30 requires corresponding adjustment of the sleeve .52 relative to the bush 51. This is effected by rotation of a worm 35 which engages worm teeth 34' on a rotatable carrier 34 which is in screw threaded engagement with a socket formed in the undersurface of the feed blade. When the spindle 21 and the feed blade 23 occupy their normal retracted positions shown in Fig. 3 the measuring compartment registers with the lower end 31' of the hopper 31 which is disposed clear of the upper surface of the feed blade but a slidably mounted spring loaded sealing sleeve 32 is maintained in sliding contact with said feed blade. The mould 11 is disposed on the arc of movement of the measuring compartment such that after the feed blade is moved to the limit of its forward motion said compartment is disposed in register with the mould cavity the lower end of the sealing sleeve 32 being then closed by the plain surface of the feed blade. In the moulding machine shown the mould 11 is a preliminary mould, the moulding M produced therein being a partly polymerized pre-shape for subsequent transfer to the lower member 37 of a final mould 45 the axis of which is arranged at the same radial distance from the spindle 21 as the mould 11. The transfer of M from 11 to 37 is effected by sliding same along the table 10 by means of a transfer arm 38 formed with a large circular opening which embraces the 'moulding M. The upper member 45 of the final mould is arranged in duplicate on a carrier disc mounted on a spindle 42 which is arranged to be oscillated through angles of 180 degrees by a rack and pinion mechanism 43. When the spindle 42 completes each movement and a mould 45 is located at the moulding position the preliminary and final moulds are closed simultaneously by means of hydraulic cylinders 20, 46. The spindle 21 is actuated by fitting to its lower end an eccentrically disposed spring-loaded cam follower 40 which is in engagement with a cam 41 on the oscillatable spindle 42.