GB544472A - Improvements in or relating to moulding presses - Google Patents

Abstract

544,472. Rotary-table moulding presses. KINGSTON, A. W., and GOOREYND, P. K. DE. (Lecluyse, E.). July 13, 1940, No. 801. [Class 87 (ii)] In a rotary table moulding press having reciprocable dies 56 and co-operating dies 21, the dies have jackets 58, 22 to which steam and cooling water are supplied in turn, and each die 56 first moves into light contact with the (thermo-plastic or thermo-setting) material, in its co-operating die 21, to pre-heat the material, then presses the material to mould it, and is finally withdrawn ; and means are provided for varying the duration of the pre-heating or of the moulding or of both of these periods. To bring a plunger into light contact with the material, each die 21 is secured to a vertically-slidable block 32 resting on a spring 35 ; as the rod 66 carrying its die 56 descends, the spring 35 is compressed, and when a flange 33 abuts a blockretaining ring 34 the block stops and the moulding proper is effected by further descent of the rod 66, the thrust being transmitted to the die 56 by the compression spring 74. To vary the period of light contact, the distance of downward travel of the block 32 (and die 21) is varied ; thus, the height at which the block 32 is normally maintained by the spring 35 may be decreased by inserting a washer between the shoulder 32a and the ring 34, and the extent of downward travel of the block may be decreased by replacing the ring 34 by a thicker ring. Each plunger assembly has three rollers 64<SP>1</SP>, 59 and 64. The rollers 64<SP>1</SP>, 64 ride anti-clockwisely on rails 16, 18, and the roller 59 travels under the rail 17. As the roller 64<SP>1</SP> leaves the rail 16 it runs down an extension 16<SP>2</SP> and the roller 59 passes under and is then depressed by an adjustable extension 17<SP>1</SP> of the rail 17, being finally held depressed for the moulding period by the rail 17. To increase the duration of moulding pressure the effective length of the rail 17 is increased by moving the extension 17<SP>1</SP> to the left so that a horizontal part 17<SP>2</SP> thereof forms a prolongation of the rail 17. At the end of the moulding period the roller 59 leaves the rail 17 and is raised by an adjustable extension 181 of the rail 18. The extension 17<SP>1</SP> and 18<SP>1</SP> are adjusted circumferentially of the machine as follows :-The extensions are supported on arms 80, 82 carried by plates 81, 83 rotatably mounted on the fixed shaft 3. These plates are shifted angularly by chains 90, 93 which are trained around pinions 88, 89 carrying segmental racks 96, 97 meshing with a worm 100 on a shaft 101 which is rotated via chain 102 and handle 103. Heating and cooling system :-A distributer comprises two chambers 115, 116, supplied with cooling water and steam through pipes 120, 119, respectively. A revolving cylindrical casing 112 brings each delivery pipe 20 in turn into contact with each chamber successively. Each pipe 20 feeds a jacket 58, the steam or water passing from the jacket 58 via pipe 23 to the jacket 22 and thence out through a pipe 24. The heating and cooling periods may be shifted around the circumference of the machine by rotating the plate 111 in which are formed the two chambers 115, 116 ; this rotation is effected by means of a pinion 122, chains 123, 124, and handle 103, in synchronism with the rotation which adjusts the cam extensions 171, 18<SP>1</SP>. The moulded articles are ejected by levers 45 hinged at 46 on the mould bodies 11, each lever having a roller 49 which, on engaging a cam groove (not shown), is moved upwards.