Patent GB-832866-A (GB)
Title: Improvements in or relating to apparatus for the cutting and moulding of ceramic materials
IPC: B28B1/02
Filed: 1957-12-20
Abstract: 832,866. Cutting ceramic blanks. SOC. CERAMICA ITALIANA S.p.A. Dec. 20, 1957 [June 1, 1957], No. 39692/57. Class 87(2). Apparatus for cutting slab blanks of a required thickness from blocks of ceramic material has movable supporting means for the blocks with the motion thereof synchronised with that of a forming machine. The blocks are spaced on a platform G, Fig. 1, which is driven in a counterclockwise direction. Each complete revolution of a shaft 22 results in a downward stroke of two swinging arms 10, 12 and the descent of the cutting wire 37 into position for the cut. The length of the downward stroke is equal to the thickness of the slab blanks which are to be cut off from the blocks a slab blank 103 being cut off from the upper end of each block successively brought into contact with the cutting wire. After each complete revolution of the platform G slabs of equal thickness will have been cut off from the series of blocks and the next revolution starts with the cutting wire 37 brought a further step downwards, after which the periodical actions of slab cutting are repeated until the last slabs are obtained. As the slabs are cut off they are transferred by the operator to the forming machine B. The downward movement of the cutting wire 37 is caused by a rotating tappet 51, Fig. 6, which engages with a roller 106 on a lever 102 and causes the lever to swing in the direction of arrow V, while an arm 110 is raised in the direction of an arrow Z and a lever 112 is rotated in the direction of arrow ZI. Due to this motion a casing 118 is caused to rotate angularly in the direction of arrow T, Fig. 8, balls 148 in recesses 150 being forced against the face 152 of a disc 120 which is thereby caused to advance by a step in the direction of arrow Zll, overcoming the braking action of pawls 124, while a lever 126 is swung round in the direction of arrow V<SP>1</SP>. The motion of the disc 120 is transmitted to a shaft 140 and, through a toothed bush 164, to a gear 156, which likewise advances by a step in the direction of the arrow Zll, while a proportion of the length of a chain 31 is wound around the gear 156 and the slide 39 carrying the cutting wire 37 is forced a step downward against the action of a counter weight 27, the downward stroke of the cutter being equal to the thickness of the slab blank to be cut. When the tappet disengages from the roller 106, the lever system 102, 110, 112 is restored by the action of a counter-weight 108 on the lever 102, the motion of the lever being limited by a bolt 200. The casting 118 is free to rotate in the opposite direction because no friction occurs between the balls 148 and the face 152 of the disc 120, which is held braked, in the position attained, by the pawls 124. Thus the cutting wire 37 will remain in position until a further rotation is performed by the shaft 140 with consequent further winding up of the chain 31. To move the cutting wire 37 downwards by hand a grip 190 can be used to turn the shaft 140 through the required amount. To move the cutting wire 37 upwards the end 182 of a lever 180 may be gripped and moved in the direction of the arrow x<SP>l</SP>, so disengaging the toothed bush 164. The slabs are placed on spindles 18, 20 on the forming machine B, a template corresponding to the shape of the finished article being secured to each spindle. The arms 10, 12 have cam faces 14, 16 associated with the spindles 18, 20 and swing in vertical parallel planes, an article being formed from a slab after each half revolution of the shaft 22.