Patent GB-1205412-A (GB)
Title: Automatic coating system
Inventor: DRUM EDWARD WALDON
IPC: G05B19/14
Filed: 1967-10-20
Abstract: 1,205,412. Coating apparatus. RANSBURG ELECTRO-COATING CORP. 20 Oct., 1967 [20 Oct., 1966], No. 47860/67. Heading B2L. Coating apparatus comprises means for delivering coating material to a coating zone, a conveyor for moving successive articles through the coating zone, means for moving the coating means transversely to the direction of conveyor movement, sensing means fixed in relation to the coating means and movable synchronously therewith for detecting the presence of an article, and means responsive to the sensing means for controlling the delivery of coating material from the coating means and for controlling the operation of saidmoving means to position the coating means during coating. Articles 20 to be coated are suspended, with their upper edges aligned, by hangers 21 from a conveyor 22 travelling from left to right. A spray gun 23 and a sensor 24 are mounted on a vertical bar 25 carried by a reciprocator 26 initially located at an upper limit switch 27. An article 20 entering the coating zone is detected by sensor 24 which is simultaneously activated by closure of a switch 28 by the hanger 21 of the 'sensed article to initiate discharge of coating material from gun 23 and downward movement of reciprocator 26, the latter also moving in the direction of movement of conveyor 22, whereby a spray pattern travels vertically down the article. When the sensing area of sensor 24 leaves the bottom edge of article 20, spraying ceases and the movement of reciprocator 26 is reversed. A lower limit switch 29 is provided to prevent overrun of reciprocator 26. In a modification switch 28 is omitted. The articles may alternatively be arranged with their lower edges aligned, when reciprocator 26 will be initially positioned at switch 29. In a further modification, adapted for coating articles having neither upper nor lower edges aligned, the spray device and sensor are initially located at a lower limit switch and upward movement thereof is initiated when arrival of an article in the coating zone is detected by a fixed sensor, spraying commensing when the lower edge of the article is detected by the moving sensor, and spraying ceasing and downward movement being initiated when the upper edge of the article is detected by the moving sensor. In an arrangement adapted to apply a stripe along the lower edge of an article 61, a sensor 60 and spray gun 63 are mounted on an arm 62 initially located at or below the upper edge of an article moving from right to left. Sensor 60 detects the leading edge of article 61 to initiate rapid downward movement of bar 62, which halts when sensor 60 detects the lower edge of article 61. Gun 63, which is thereby aligned with the lower edge, is activated when the leading edge is detected by a fixed sensor 64. When the trailing edge passes sensor 64, gun 63 is turned off and bar 62 is returned to its upper position. Coating material may be discharged either by air pressure or by electrostatic action, and may be in the form either of liquid or of powder. The sensing devices may operate either magnetically, or pneumatically, or optically, or physically as by feelers or the like.