GB1111371A - Improvements relating to the internal coating or treatment of pipes - Google Patents

Abstract

1,111,371. Coating apparatus. AULT & WIBORG PAINTS Ltd. 24 Aug., 1966 [24 May, 1965], No. 21973/65. Heading B2L. In coating the inside of a pipe the pipe and a spreading device situated for co-axial entry into the pipe are caused to move rotationally and longitudinally relative to one another to spread an appropriate quantity of coating medium previously deposited, along the pipe. A pipe 1 is supported on a series of plates 4 mounted on side rails 2 carried by trestles 3. A shaft 11 is mounted for longitudinal and rotational movement on a similar support structure consisting of carriers 8, 9, 10; side rails 6 and trestles 7, so as to be co-axial with the pipe 1. Rotational movement of the shaft 11 is effected by motor 19 through gearbox 20 and longitudinal movement is effected through motor 25 through a chain drive mechanism. Alternatively a single motor may be used by both movements. The carriers 8, 9, 10 can be rotated in unison to positions I, II or III to provide appropriate support positions to the shaft 11 during its longitudinal movements. In use a cannister 31 into which coating material has been poured through aside slot 31a (Fig. 17, not shown) is attached by a bayonet connection to the shaft 11 and the shaft is advanced until the cannister 31 is just inside the pipe 1. The shaft 11 is then rotated through 180‹ so as to bring the slot 31a to its lowest position. The shaft 11 is then moved longitudinally through the pipe 1. The cannister is slightly less in diameter than the pipe so that coating material is deposited from the cannister 31 on to the inside of pipe 1. As the cannister emerges from the other end of pipe 1 the shaft is again rotated 180‹ to bring the slot 31a to its uppermost position and the cannister is then removed from the shaft 11. A spreading device, Fig. 16, is then attached to the shaft 11, motor 19 is switched on to rotate the shaft 11 and motor 25 is switched on and gear box 27 or 29 operated to cause reverse longitudinal movement of the shaft 11. The spreading device is thus drawn back through the pipe and by the combined successive action of the spreading combs 36 and the brush heads 41 the coating material is spread uniformly on the inside of the pipe. The toothed edges of the combs 36 are biased radially outwards by two series of coil springs 39 and a tapered radial guide having vanes 35 is provided for facilitating entry of the spreading device into the pipe.