spraying apparatus suitable for decorating articles of earthenware, pottery or chinaware or similar workpieces

摘要

A machine for decorating e.g. banding dishes and similar articles 2 comprises a device, e.g. a pair of driven rollers 3, for supporting and rotating the dish, a spray gun 24 directed towards the rollers 3, a plate 41 on a carrier, e.g. a bar 48 adjustably mounted on a pillar 38, which is movable so that the plate 41 can approach the dish 2 in the path of the spray and be retracted from the dish 2, means for moving the carrier 48, 38, and means for supplying compressed air to the gun 24 when the plate 41 is near the dish 2, the means acting in synchronism with the rotation of the dish 2 whereby the dish completes at least one revolution while the gun 24 is operated and the plate 41 is in operative position. A mask 126 is adjustably bolted at 127 to the plate 41 with the outer edge of the mask 126 more to the edge of the plate 41 to provide a space down which liquid droplets may flow to ensure a sharp edge to the coloured band on the dish 2. The gun 24 is adjustably mounted on the pillar 38 which is movable horizontally in a slot in a table 1 which supports the entire apparatus, including an inclined plate 9 which has spindles, as 8, 6 respectively, for a platen 5 for the dish 2 and for the rollers 3. A motor PICT:0841838/III/1 PICT:0841838/III/2 21 drives a pulley 17 on a shaft 16 which carries a pulley 15 and a belt 14 for driving the rollers 3, which may be rubber-covered, and a worm 103 engaging a gear wheel 102. A cam track 99 in the wheel 102 controls the operation of the apparatus as follows:-During part of the rotation of the wheel 102 a ball 98 on an arm 97 falls into a gap in the track 99 to actuate a mercury switch 93 and so to energize a coil 88, Fig. 11, in a valve 77 which thus passes compressed air through a line 86 to a cylinder 56 to move a piston rod 52 against a spring 66 to the right. The pillar 38 is secured to the rod 52 by a collar 51 and is hence moved to carry the gun 24 and plate 41 clear of the dish 2. Movement of the collar 51 allows a spring-pressed arm 114, Fig. 11, to pivot and permit a valve 106 in an air line 105, 107 to close and to cut off compressed air to an inlet 28 on the gun 24, which thus ceases spraying. When the track 99 engages the ball 102, the valve 77 is closed, the spring 66 advances the carrier 38, 48 to the left, air going to atmosphere at 81, and the collar 51 engages the arm 114 to open the valve 106 and actuate the gun 24. A ball 121 on the bar 48 engages a cup formed in a hub 122 on the plate 41 which carries a trough 133, for recovering liquid spray material, and the adjustable mask 126 spaced by washers 128 from the plate 41. Air is supplied by a line 136, Fig. 11, to a pipe 131 leading to a space between a plate 132 and the back of the plate 41 where the air forms a thin screen to improve the decoration of the dish 2. A further air line 137, Fig. 11, delivers air to a liquid supply tank 27 which communicates at 26 with the gun 24.