Patent GB-983715-A (GB)
Title: Improvements relating to the finishing of articles of clay-ware
Inventor: ROWLEY THOMAS HENRY
IPC: B24B9/12
Filed: 1962-07-20
Abstract: 983,715. Finishing articles of clay-ware. CLOUGH'S ROYAL ART POTTERY Ltd. Oct. 14, 1963 [July 20, 1962], No. 27994/62. Heading B3D. In a machine for finishing articles of clay-ware a fettling tool provided with a sufficiently rough operative surface to enable it to exert the desired fettling action is mounted alongside a rotating head by which a plate can be supported, and the fettling tool is mounted and operated so that it initially makes contact with one surface only of the marginal portion of the plate, and is then subjected to a tilting motion whereby it progressively rides round the actual rim or edge of the plate, and eventually comes into contact with the opposite surface of the marginal portion. A vertical spindle 11 mounted in a frame 10 has a concave head 12 lined with felt or other soft material to receive a plate 16. Two centralizers 13 provided with felt or similar faces 15 shaped to fit the edge of the plate are mounted on spindles 14 which can be partially rotated to swing the centralizers into engagement with two portions of the edge of the plate, thus locating it centrally on the head. A vertical plunger 17 carries a felt or similar pad 18 engageable with the centre of the plate, thus holding it on the head. A vertical rod 22 loaded by a spring is operated by a cam 20 on a cam-shaft 21 driven at a predetermined speed and is connected by a lever 23 to the plunger 17. A collar 25 fixed to the rod 22 has anchored thereto cables 26 operating levers 29 attached to the centralizer spindles 14. When the pad 18 is raised the centralizers move inwards to centralize the plate; when the pad 18 is lowered the centralizers move outwards. A felt or similar pad 31 having a lower edge shaped to extend, in intimate contact with the upper surface of the plate, from the circumference of the pad 18 to the edge of the plate, is carried by a radial arm 30 pivoted at 32 to a tube 35 secured by a screw 36 in adjusted position on the plunger 17; the arm 30 is lightly loaded by a spring 33, the tension of which can be adjusted by a screw 34. The pad 18 may also be mounted on the tube 35 if desired. When the plate 16 is rotated by the head 12 its surface is subjected to towing or polishing by the pads 18, 31. The fettling tool 40 is then brought into operation. This is in the form of a flat, or nearly flat, piece of natural or artificial stone, metal or other material having a somewhat abrasive surface, pivotally mounted on a bracket 41 carried by a cranked arm 42 carried by a pillar 43. To swing the tool inwardly towards the centre of the plate the pillar 43 is turned by cables 45, 46 connected to rocking levers 47, 48 operated by cams 51, 52 on the cam-shaft 21. When the tool 40 first contacts the edge of the plate it is in an inclined position engaging the underside of the edge. As the arm 42 moves further inward the tool is tilted into a vertical position and then into an inclined position engaging the top side of the edge. The mounting of the arm 42 on the pillar 43 is such as to allow for radial and vertical adjustment to suit different workpieces. The tool 40 is loaded by a spring 54 connected between the tool and an anchorage 55 adjustable on the arm 42. Associated with the fettling tool 40 is a polishing tool 57, in the form of a stone contoured to the finished contour of the edge, carried by a pillar 58 operated through a lever 59 by one of the cables 26 so that as the centralizers are withdrawn the tool 57 begins to move inwards but does not contact the edge until the tool 40 has removed the rough edge. The cam-shaft 21 is preferably driven by motors through variable speed gearing enabling the speed of the operations to be suited to requirements. The drive to the spindle 11 is such that when the fettling operation is completed the speed of rotation can be increased for the polishing operation, e.g. by a switch operating automatically at the appropriate stage in the cycle. At the end of the cycle a cable anchored to the collar 25 moves a brake shoe into engagement with any convenient member of the driving gear to stop rotation of the head 12.