GB1300011A - Web registry control apparatus - Google Patents

Abstract

1300011 Registering webs KNOX Inc 1 Jan 1971 129/71 Heading B8R Apparatus for transverse registering of a continuously moving web 12, Fig. 1, comprises a pair of rollers 22, 23 mounted on a frame 15 which is pivotally mounted on a vertical pivot 18 and actuated by a fluid piston cylinder assembly 28, 30 under the control of a threeway valve 42 actuated in turn by pressure differentials applied through lines 61, 62 to the ends of the valve, the pressure differentials being produced by transverse displacement of the web with respect to first and second sensing zones defined by fluid jet orifices in a sensing head 55. The sensing head has a first sensing zone defined by ports 74, 66, Fig. 3, associated with respective orifices 92, 102, a second sensing zone defined by ports 78 and 76, 64 and associated with respective orifice 118 and 106, 112, and a null zone disposed between the first and second zones and corresponding to the registry. The sensing head is connected to fluid supply means by conduits 70, 71, 72 such that when the web is in the null zone a jet from orifice 92 passes into the orifice 102 and a jet from orifice 106 passes into the orifice 112, the orifices 102, 112 being connected through lines 61, 62 to the ports 67, 68, Fig. 6, of the valve 42 and since both jets act on the respective diaphragms 126a, 126b of the valve no pressure differential is produced and hence the registering device is not actuated. The jet passing from the orifice 106 to the orifice 112 is adapted to be deflected by the jet from orifice 118 when the web edge has moved from the null zone towards the free end of the sensing head uncovering the bore 110 which allows the jet from the orifice to enter the bore and disrupt the jet passing between the orifices 106, 112, whereby a pressure differential is applied to the valve port 68 by the orifice 102 and the valve plunger 134 is displaced towards the valve port 67 and fluid pressure is applied to the cylinder chamber 36 through line 40. Displacement of the web in the opposite direction causes the jet issuing from the orifice 92 to be interrupted whilst the jet issuing from the orifice 106 is enabled to register a pressure differential at the diaphragm 126a associated with the valve port 67. In consequence fluid is admitted to the opposite cylinder chamber 34. Respective other chambers are vented through discharge ports 47, 48 formed by adjustable sintered discs.