GB1018221A - Improvements in or relating to machines suitable for use in the manufacture of pottery - Google Patents

Abstract

1,018,221. Printing on pottery. SERVICE (ENGINEERS) Ltd. April 26, 1962 [April 26, 1961], No. 15026/61. Heading B6C. [Also in Division B3] A machine for use in operating upon flat-ware articles in the manufacture of pottery, such as the abrading of, or printing of a decorative design on a plate, comprises means for moving a plurality of work supports 24, Fig. 1 (not shown), one after another through a workcentring station 26 and work-centring means 82 arranged to embrace a workpiece by engagement with it at spaced localities around its periphery, the work-centring means operating twice on each workpiece at the station so that the workpiece is accurately positioned by being embraced, released and then embraced again. The work supports 24 are rotatably mounted on arms 18 extending from a shaft 22 driven by a Geneva mechanism comprising a slotted disc 30 co-operating with a roller 34 on an arm 32 carried by a cam-shaft 36 driven by gearing 38 from an electric motor 40; a cam 33 on the shaft 36 actuates a pawl 35 on a lever 37 to engage notches in locking disc 31 to retain the work supports in their indexed positions. Another cam 132 on the shaft actuates the work-centring means which consist of pads 82 carried by arms 80 secured to spindles 86 rotatably mounted in a spider 92 having arms 90. Forked levers 96 are secured to the spindles and to interconnecting links 118, Fig. 2 (not shown), and one of the levers 96 is secured to a lever 120 urged by a spring into engagement with a roller 122 on an arm 124 at one end mounted on a pivot 126 and at the other end having a roller 130 engaging the cam. A further cam 114 on the shaft 36 engages a roller on a lever 106 connected by a rod 104 to a lever 100 joined by a link 102 to the spider which is thereby raised and lowered. The lever 100 has a second arm which is connected to a towing tool, such as described in Specifications 652,965 or 1,013,419 consisting of a contoured tool for engaging the workpiece diametrically. Each work support has an annular rim 44, Fig. 4 (not shown), for receiving a workpiece and a suction pad 48 connected by a passage 50 to an annular space 56 in a sleeve 54, each space 54 being connected by pipes 58 and passages 60 to respective valves 62 which are connected to a passage 65 leading to a suction pump. The valves are controlled by a plate 64 raised and lowered by a lever 68 engaged by a plunger 70 co-operating with a cam 74 on the shaft 36. When the plate is lowered, suction is cut off from all of the work supports except that at the towing station, a post 76 maintaining the valve controlling the suction to that support in a position connecting the pump to the support. In operation, while a workpiece is being centred at one station 26 and another workpiece is being operated on at another station 28, an operator removes a finished workpiece from a third station and places a new workpiece on the support at the fourth station. As the shaft 36 rotates, the cam 74 lifts plate 64 to operate the valves and apply suction to the work-supports not at the work-operating station 28, the work-support at that station already being connected to the suction pump. Further rotation of the shaft causes the Geneva mechanism to rotate the shaft 22 moving the supports to the next station. As the new workpiece reaches the work-centring station 26 the plate 64 is lowered to relieve the suction at all but the work-operating station 28 and cam 114 is operated to lower the lever 100 and the workcentring device and the towing tool, the tool then operating on the workpiece which is rotated by a friction disc raised by a cam into engagement with a friction disc 140 on the work support. The cam 132 then rocks the levers 128, 124 so that the arm 120 actuates the levers 80 and moves the pads 82 into engagement with the periphery of the workpiece which is thereby centred. As the workpiece is slightly conical, when it is released from the pads it may fall onto the ring 44 from a tilted position so the cam 132 causes the pads 82 to re-engage the workpiece to accurately centre it on the support. Further rotation of the cam-shaft 36 causes the spider 92 to be raised and the work supports to be moved to the next station, suction being connected to the supports before they are moved.