Improvements in and relating to method and apparatus for the manufacture of clay bodies

摘要

353,410. Pottery manufacture; moulds. CRUIKSHANK, J. W., Langley Park, Montrose, Angus.- (Assignee of Preston, F. W.; 602, National Bank Building, Butler, Pennsylvania, U.S.A.) March 7, 1930, No. 7537. Convention date, March 7, 1929. [Class 87 (i).] In forming clay vessels the plastic material, while being rolled on to a mould surface, is consolidated by alternate distortion and reshaping to eliminate voids and expel air from the interior of the material. In the apparatus shown in Fig. 1 clay is dropped into a mould, which may be of the elliptical form shown in Figs. 4 and 7. The clay is spread out by bottom-forming rollers 47 which are freely mounted on a spindle 48 which is rotated about its centre by a shaft 49 in the opposite direction to, and at a greater speed than, the mould. The clay is simultaneously consolidated by a freely mounted conical roller 46. The shaft 49 is journalled in a block 50 vertically slidable in a guide-block 50a which is slidable on horizontal rails 18 fixed to the frame 16 of the machine. The shaft 49 is driven from the shaft 52 by helical gears 51, one of which is slidably keyed to the shaft 49 and the other of which is slidably keyed to the shaft 52 to permit vertical and horizontal movement of the former shaft without breaking the driving connection. The consolidating roller 46 is idly rotatable on a bracket 62 which is supported by a frame 69 rotatably supported on an upright 63. A spring (not shown) fastened to an extension of the frame 69 presses the bracket 62 against the side of the pot, where it is located by rollers 72. By this means the base of the roller 46 remains close against the mould surface irrespective of the shape of the mould. As shown in Fig. 4 the axis of the roller 46 is inclined in plan to the radius vector of the mould so as to prevent clay from passing between the roller and the sides of the mould during the formation of the bottom of the pot-an effect which may be still further prevented by forming the roller 46 with a peripheral groove terminating in a sharp edge as shown. The rollers 47 are partly counterpoised by a weight 58, and the roller 46 by a weight 65, so that both rollers rise up automatically during the building up of the pot. When the bottom of the pot is completed the rollers 47 are slid away and replaced by the roller 80 which is mounted on a shaft 81 in a sleeve 87 which can be raised or lowered by a hand-wheel 84 and a rack and pinion, the whole being mounted in a block 82 horizontally slidable along the rails 18. The stop 811 positions the roller with respect to the bottom of the mould and the thickness of the side wall of the pot is accurately determined by the handwheel 92 on shaft 90 screwed into the bearing block 91 of the shaft 81. The shaft 81 is driven in the same direction as, and at a higher speed than, the mould. During the formation of the side walls of the pot the roller 46 continues to bear on the clay but may be counterpoised more than when forming the bottom. When the sides reach the desired height a trimming roller 93 freely mounted on a vertical spindle is brought against the edge of the pot to smooth the outside thereof and cut off the clay at the desired height. The mould, Fig. 7, may be formed in four sections, two of larger radius aa1 defined by arcs of circles struck from points a on the minor axis and two of smaller radius ba1 struck from points b on the major axis. The sections are pivoted together at 95, 95a and 95b and are detachably connected at 96 so that the mould walls may be swung apart. The bottom 35 of the mould is supported on a truck 36 and may be wheeled with the finished pot off the mould table 30. The mould is rotated by a pinion 28 in constant engagement with a ring gear 29 on the mould table, which is correspondingly shaped to the mould and is rotatably mounted on an oscillatable wheeled support 31 kept pulled to the left by a weight 40. By this means the rollers 47, 80, which act on the side of the mould adjacent the gear 28, can be accurately located relative to the interior surface of the mould. The plastic clay is extruded progressively from the spout 43 of a pug mill and cut by a knife 44a into lengths which fall into the mould near the rollers 47, 80. The shaft 52 and the pinion 28 are driven by the gearing shown in Fig. 1 from the main driving pulley 19 of the apparatus. In a modification, Fig. 13, the bottom-forming rollers 110 and side-forming roller 111 are mounted on a rotatable T-head 100. The rollers are driven by helical gears 114, 126 on shafts 115, 127 driven through shaft 104 and bevel gears from a driving pinion 109. The roller 111 may be moved horizontally by rotating a threaded rod 124. The T-head may be held against revolution by engagement with a fixed standard 137. The consolidating roller 138 is supported on a rod 140 slidably mounted on an upright 141 and counterpoised by a weight 142. Specification 322,804, [Class 87 (ii), Moulding plastic &c. substances], is referred to.