GB843193A - Improvements in or relating to apparatus for use in the treatment of a continuously-fed length of material - Google Patents

Abstract

843,193. Cutting glass tubing. GENERAL ELECTRIC CO. Ltd. April 2, 1958 [April 8, 1957], No. 11428 /57. Class 56. In apparatus for operating on a particular region in a continuously-fed length of material, such as glass tubing emerging from a tubedrawing machine, and in which the operating member travels with the material while operating on it and is then returned to the starting position to repeat the operation, the operating member carries two clutches each arranged to clutch the member to, or declutch it from, the oppositely-moving sides of an endless band (or bands) running parallel to the material, the clutches being governed by control means which are adjustable to vary the time interval between clutching and declutching so as to vary the length of stroke of the operation. The invention is shown applied to apparatus for severing into adjustable predetermined lengths glass tubing 3 continuously fed in the direction of its length, the severing being effected, entirely or partly, by means of a ring burner 6 mounted on a carriage 1 which is alternately clutched to the upper and lower flights of a driven endless chain 7 (or alternately clutched to two oppositely moving chains). The carriage during its forward movement travels with and at the same speed as the advancing tubing, the burner surrounding an annular zone of the tubing at which severance is to take place, and the interval between the clutching and declutching of each clutch is made adjustable so as to vary the length of stroke of the carriage and hence the length of tubing severed. The actual severance may be by the melting effect of the gas burner only as in Specification 843,192, or by such melting followed either by the passage of an electric current around the heated ring as in Specification 808,284 or by thermal shock. Sprocket wheels 11, 12 engaging the chain 7 and fast on shafts 13 normally rotatable on the carriage 1 are alternately locked to the carriage by electro-magnetic clutches 14, 15 which are alternately actuated by cams 20, 19 on the carriage engaging, respectively, microswitches 18, 17 at the ends of the forward and backward strokes of the carriage. One switch energises one and de-energises the other clutch, and the other switch de-energises the one and energises the other clutch. The positions of the holders 28 of the switches may be adjusted along a rail 28 to vary the timing. Switch 18 may however be omitted and the switch 17, in addition to energising clutch 14 and de-energising 15 when operated by cam 19 may initiate operation of an electronic timing circuit which will perform the same functions as the parts 20/18.