GB1246613A - Improvements in or relating to machines adapted for use in the manufacture of ceramic ware - Google Patents

Abstract

1,246,613. Moulding clay pieces. SERVICE (ENGS.) Ltd. 30 Oct., 1968 [31 Oct., 1967], No. 49333/67. Heading B5A. [Also in Division F2Q] Clay pieces P, for moulding into flatware, e.g. plates, dishes and saucers, by the action thereon, whilst supported on a mould Q rotating on a jigger head 540, of a heated generally conical roller tool which rotates about an axis which progressively increases in inclination to the vertical, are preformed by apparatus comprising a pair of diametrically opposed claycarrying rotatable heads 140, 142 which are incrementally displaceable, by 90 degree intervals, through four stations A-D. At station A an extruded clay column R, which is intermittently advanced on a conveyer 520, is cut by the horizontal wire 522 of a reciprocating, cutter, to fall on to a horizontal support (280) of a carriage (278), Fig. 8 (not shown), whereon it is horizontally reciprocated beneath a head, 140 or 142, against which it is then pressed to reduce its thickness by 1/3 to 1/2 by upward displacement of the carriage (278). The clay is retained on the head by suction applied through a porous sintered aluminum surface thereof as the carriage (278) is lowered, release from the latter being facilitated by a surface covering of a sheet of rubber (281). At station B the head is rotated, from a motor 168, as the clay piece P is lubricated, by a water spray 371, and is trimmed on the lower surface thereof by a facetrimming tool 340, which is vertically reciprocable into operative engagement, and is simultaneously trimmed around the periphery thereof by an element 408 of an edge-trimming tool 380 which is horizontally urged into resiliently yieldable contact with the clay piece P. The trimmed clay is deflected by a vertical shield 436 on to a conveyer belt 420. At station C, a mould Q, delivered thereto by the turntable T of the conical roller moulding machine, is raised by a mould support 450 into resilient engagement with the preformed clay piece P on the head which is released on to the support 450, upon replacing the suction through the porous head surface by a pressure above atmosphere. The support 450 is then lowered and the mould Q with the preformed clay piece P thereon is removed from the support 450, by upward displacement of turntable T, and is then deposited on the jigger head 540 by lowering turntable T after rotation thereof through 90 degrees, a fresh mould Q simultaneously being deposited on support 450. At station D, the porous surface of the head is cleared by blowing air therethrough as it is simultaneously rotated in contact with a horizontal rubber blade (494), Fig. 14 (not shown). The heads 140, 142 are mounted on arms 126, 128 of a casting which is incrementally rotated through 90 degrees by a Geneva mechanism, Fig. 13 (not shown), the drive member (72) whereof is mounted on a main cam-shaft (82) and is provided with convex locking surfaces (78) engaging concave surfaces (80) of the driven wheel (70) between steps of rotation thereof; braking also being assisted by a brake shoe (52), Fig. 5 (not shown), acting on the drive shaft (32) of the head casting and controlled by a cam (122) on the main cam-shaft (82). Suction and pressure air are supplied to the heads 140, 142 through respective tubes 208, 208<SP>1</SP> passing through the drive shaft (32) and supplied, via a manifold sleeve 232, from valves 240, 246, each actuated by separate cams 252 on a cam-shaft (254), Fig. 6 (not shown), rotated at half the speed of the main cam-shaft 82. The carriage (278) is horizontally reciprocated by a bell-crank lever drive from a cam on the main cam-shaft (82), and is upwardly displaced to press the clay against a head 140 or 142 by a plunger (298) reciprocated from the cam-shaft 82, via a lever arrangement (314) having a manually adjustable fulcrum whereby the displacement of the plunger (298) may be adjusted to vary the thickness reduction of the clay piece. The facetrimming tool 340 is vertically reciprocable into operative engagement with the clay piece by a similar adjustable drive from the main camshaft (82), Fig. 10 (not shown). The edgetrimming tool 380 is horizontally displaced into operative engagement with the clay piece by rotation of a spindle 384 also actuated from cam-shaft 82, via a lever arrangement; a screw 390 and spring 392 providing an adjustable and resiliently yieldable mounting of the element 408 on the spindle 384. The mould support (450), Fig. 11 (not shown), is vertically reciprocated from the main cam-shaft (82), via a lever arrangement (474) permitting vertical adjustment of the support (450), the arrangement being such that the support (450) is resiliently urged upwardly against the head by a spring acting on the lever (474) and downwardly by the cam action on the lever (474) against the spring. The operation of the preforming apparatus is effected through a microswitch actuated relay circuit controlling the drive motor for the cam-shafts (82 and 254) and the motor 168 which rotates the heads 140 and 142. During the completion of a moulding operation on the conical roller machine, the heads are stationary at stations B and D with suction and pressure respectively being applied thereto. Upon removal of a mould Q with a preformed clay piece thereon and replacement with a fresh mould on support 450 by the turntable T, a microswitch on support 450 initiates the drive to the cam-shafts (82 and 254), the rotation of the motor 168 and actuation of the cutter wire 522 and conveyer 520 being controlled from microswitches actuated from the main cam-shaft (82). A probe 504 adjacent station D, if deflected, halts the driving motors of the preforming machine.