Patent GB-833360-A (GB)
Title: Improvements in or relating to the production of articles of ceramic ware
IPC: B28B1/24
Filed: 1956-05-10
Abstract: 833,360. Making and attaching cup &c. handles. BRITISH UNITED SHOE MACHINERY CO. Ltd., and BOX, R. L. May 9, 1957 [May 10, 1956], No. 14505/56. Class 87(2). [Also in Group X] Apparatus for forming cup handles and attaching such handles to cup bodies comprises a mould M, an injection device E to introduce plastic clay into the mould cavity and comprising a member C which co-operates with the mould M, a sensing device D and a cup support S. The mould is in two parts 6, 8, Fig. 4, made of grains of sintered silicon carbide forming a porous material, mounted in block 10, 12 to leave cavities 114,116 and co-operating to enclose a mould cavity 113 adapted to form a cup handle. The cavities 114, 116 are connected by flexible pipes 122 to a source of compressed air. Externally the mould parts and blocks 6, 8, 10, 12 are contoured to the shape of a cup body B. The blocks 10, 12 are fixed to members 60, 66 which are pivoted on the end of cranked arms 56, 58 with a travel limited by pins 63, 69 which lie in slots in the arms. The arms 56, 58 are pivoted on a vertical shaft 54 and have lugs 96, 100 from which pins 94, 98 project downwards into camming slots 90, 92 in a cam disc 86 the shaft 84 of which is rotatable by a worm 108 which meshes with a worm-wheel 88 thereon. The worm 108 is rotatable by a hand-wheel 110 through a friction clutch 112. The shafts 54, 84 are mounted in a casting 18. The casting 18 is mounted on a plate 14 which is pivoted to a base-plate 2, in which there are holes 127, 129 engageable by a spring loaded handle 126 fitted to the plate 14, which may thus be locked in one of two positions. Blocks, e.g. 20, on the casting 18 engage a groove 16 in the plate 14, and the casting may be moved along the groove relatively to the plate by turning a hand wheel 32 to which a screw-threaded sleeve 34 is fixed, which is in threaded engagement with a rod 32 which passes through it and which therefore advances when the hand wheel is turned and moves a bar 24, to which it is screwed, through a hole in the block 20 and compresses a spring housed in a bore in the casting 18, parallel with the groove 16, to impart a thrust to the block at the opposite end of the casting 18 and so move it to the left as in Fig. 1. If the movement of the casting is prevented the spring is merely compressed. The effective length of the spring may be altered to adjust its compression. The injection device E includes a base casting 128, pivoted on a shaft projecting vertically from the base-plate 2, and a bracket 160 bolted to the base-plate. An arm 132 projects from the casting 128 and has a handle 134 on its end spring loaded to be located in a hole in the base plate 2. The injection orifice 142 is formed in a head 138 which is fixed to the casting 128, Fig. 3, and which has an outer face 139 shaped to correspond with the contour of the cup body. B. Plastic clay is forced from a cylinder 144 by the advance of a piston head 182. A pulley 162 is rotatably supported in the bracket 160 and is screw threaded on a rod 166 which has a longitudinal groove co-operating with projections from the bracket to prevent rotation. When the pulley is rotated, driven by a motor (not shown) through a belt 164, the rod 166 moves axially and pushes the piston-rod 178 to advance the piston head 182 and force clay through the injection nozzle. To guard against the piston head 182 being driven into the orifice 142 an arm 176 on the rod 166 operates a limit switch 174 and stops the motor. Another limit switch 172 stops the motor when it has been running in reverse to retract the rod 166. The sensing device D, which suspends the action of the injection device E when the mould cavity is full, comprises a metal sleeve 152 and a rubber sleeve 150 which are housed in a bore 146 in the head 138. The pressure of clay from the other end of the cavity moves the sleeve 152 outwards and causes an arm 156, connected to the sleeve, to operate  a  microswitch 158 to reverse the motor, whereby the rod 166 is retracted. The rubber sleeve 150, which has been stretched, then. moves the sleeve 152 back again and the microswitch is so constructed that this movement switches off the motor. The cup support S. Fig. 6, comprises a member 214 shaped to receive the cup B and screwed on a pin 208 which is rotatably mounted in the end of an arm 190. The rotational position of the member 214 is determined by that of a disc 210 on the pin having equally spaced depressions 212 in its upper face, into one of which a spring loaded phmger 222 enters. The cup support may be moved by sliding a casting 188, from which the arm 190 extends, on a fixed slide 184, springs 192 pulling it towards the mould. The casting 188 is locked in its sliding position by the action of a spring loaded plunger 204 on one arm of a bellcrank 194, which causes a roller 200, held between the lower ends of two prongs 196 forming the other arm of the bell-crank, to become wedged between the slide 184 and the inclined face of a tapered gap 202 in the bottom of the casting 188. In operation, (1) plastic clay (about 23% water content) is placed in the bore 145 and engaged by the piston head 182, (2) the hand-wheel 110 is rotated to close the mould members 6, 8 until the friction clutch 112 begins to slip, (3) the hand-wheel 38 is rotated to move the mould members 6, 8 (leftwards, Fig. 1) into firm contact with the injection head 138. All the time air at a temperature of 160-180‹F. is supplied to the cavities 114, 116 through the pipes 122 and passes out through the mould surfaces. A motor is started to rotate the pulley 162 and cause the rod 166 to move to the right, Fig. 1, and so bring about the injection of the clay into the mould cavity. When the required quantity has been injected, as governed by the sensing device D, the hand wheel 38 is slackened off, the handle 134 is released from its hole in the plate 2 and the casting 128 is turned anti-clockwise on its vertical shaft, separating the moulded handle from the clay in the cylinder 144 and forming faces F, F, Fig. 6, on the handle to match the contour of the cup body B. The handle 126 is then disengaged from the hole 127 in the plate 2 and the plate 14 rotated until the handle engages the hole 129, thus bringing the mould operating mechanism opposite the cup support S. A small amount of sticking-up slip is applied to the exposed faces F,F of the handle in the mould by a hand brush, and the mould members 6, 8 are then moved forward by rotation of the hand wheel 38 until the faces F, F contact the cup body B. The casting 188 yields somewhat against the springs 192, and the handle is held in contact with the cup body B until it is affixed thereto : this is effected in less than a minute. Rotation of the hand wheel 110 is then carried out to move the mould members 6, 8 away one from the other, leaving the handle affixed to the cup body B. Though the blocks 10, 12 the mould members 6, 8 thus move out of contact with the cup, the casting 188 does not move forward under the action of the springs 192 because of the locking action of the roller 200 in the gap 202. When subsequently it is desired to return the casting 188 to its forward position the locking action is terminated by depressing the bell crank 194. Specifications 687,172 and 719,626 are referred to.