GB390888A - Improvements in or relating to automatic means or apparatus for feeding alternately predetermined different weights of molten glass - Google Patents

Abstract

390,888. Glass manufacture. WOOD, J. T., 21, Duffield Road, Pendleton, near Manchester. Dec. 11, 1931, Nos. 34330/31 and 20780/32. [Class 56.] Afeederof the reciprocating plunger type, such as that described is Specification 213,406, [Class 56, Glass], is provided with means for varying the stroke of the plunger in order that glass charges of different weights may be delivered in predetermined order. The feeder comprises a forehearth 1, Fig. 1, having an outlet through which charges of glass are delivered by a plunger 10 which is reciprocated vertically by means of a compressed-air cylinder 5. The piston rod 9, to which the plunger is secured, slides through a sleeve 12 which can be raised or lowered when a bevel wheel 16 is turned by a hand-wheel 24 secured to a shaft 23. A stop 26, fixed to the piston rod 9, makes contact with the sleeve 12 and limits the downward movement of the plunger, so that the size of the charges delivered by the plunger can be varied by turning the hand-wheel 24 either by hand or automatically as described in Specification 389,923. According to the present invention, a bifurcated distance-piece 29, Fig. 2, carried by a lever 31 which is pivoted to a bracket 35 secured to the top of the sleeve 12, is moved into or out of the path of the fixed stop 26 by means of a compressed air cylinder 39 secured to the operating cylinder 5. By operating the cylinder 39 in synchronism with the movement of the plunger, the plunger can be made to move with alternate long and short strokes and charges of two different weights can be delivered. Instead of being mounted on the cylinder 5, the cylinder 39 may be mounted on an extension of the bracket 35, as shown in plan in Fig. 9, its piston rod 38 being connected directly to the support 49 of the distance-piece. The upper surface of the distance-piece may be inclined or formed into a series of steps 53, 54, 55, so that by regulating its inward movement, the variations of the stroke of the plunger can be increased. The regulation can be effected by moving a distance-piece 56 into the path of an upstanding part 48 on the support of the distance-piece 29. The distance piece 56 can be moved either by means of another compressed air cylinder, or by means of a rotating cam 60. The cam is turned in one direction by a pinion 71 which is engaged by a rack 72 secured to the piston rod 9 that operates the plunger. The pinion 71 turns the cam 60 in one direction by means of a ratchet and pawl. In another construction, the distance-piece 29 is replaced by two arms which are pivoted on the bracket 35, Fig. 2; and are opened and closed by the cylinder 39. In a further construction, the piston rod of the cylinder 39 is made in two parts one of which screws on to the other, and one of the parts is rotated by an air cylinder periodically in order to move one or the other of the steps on the piece 29 into the path of the stop 26. The cylinder 39 is operated by a valve similar in construction to the valve described in Specification 229,804, [Class 56, Glass]. Specification 390,883 is also referred to.