| 摘要 |
<PICT:0589582/III/1> <PICT:0589582/III/2> A shield is located in the path of a spray gun, means being provided whereby, on one of a series of articles which it is desired to paint being presented to the spray gun, the shield is withdrawn; such means, however, being inoperative if one of such articles should not be present. The apparatus is designed mainly in connection with the apparatus for coating mica plates as described in Specification 589,581 in which the plates are successively conveyed on to a suction nozzle and held by the nozzle while being sprayed. This invention ensures that, if the nozzle fails to pick up a plate, the spray will be intercepted by the shield and so will not foul the suction nozzle. Referring to Fig. 1, with a plate over the mouth of the suction nozzle connected to tube 10, the suction pressure in the cylinder to tube 10, the suction pressure in the cylinder 9 draws the piston 8 against the action of the spring 11, whereby the shield 2 is withdrawn from the position covering the nozzle 1 of the spray gun. When no plate is held against the suction nozzle, suction in the cylinder 9 ceases and the spring 11 operates to restore the shield 2 to its covering position. Another form of the invention is illustrated in Fig. 2. On rotation of the cam 15, the piston 12 is moved to the right, and with the suction nozzle which is attached to tube 14 covered by a plate, suction is produced in the left-hand end of the cylinder 13 which will thus rock about its pivot 22 with the result that the shield 30 will be moved from its covering position. With the plate absent, insufficient pressure is induced in the cylinder 13 and the spring 24 will maintain the cylinder in contact with the stop 23 so that the nozzle of the spray gun 31 remains covered. On completion of the stroke of the piston 12, a port 32 in the cylinder is uncovered whereby suction is relieved, this action being timed to take place when it is required that the plate be released by the suction nozzle. |
