GB462960A - Improvements in and relating to web guiding apparatus - Google Patents

Abstract

462,960. Fluid pressure servomotorcontrol systems. HARNDEN, Ltd., C. A., and HARNDEN, C. A. Oct. 20, 1936, No. 28464. [Class 135] Guiding means for a web 4 which is being taken from a roll 3 comprises a piston 12 which is actuated by fluid pressure supplied from pumps 19, 20 to move the spindle 5 carrying the roll in an axial direction to correct any misalignment. The supply of the pressure fluid to the piston 12 is controlled by a valve 17 which is in turn controlled by the degree of suction on a piston 30 in a pneumatic cylinder 31. To actuate the valve 17 a further valve 37 and a piston 38 are provided, a connection 41 being taken to a vacuum pump and a connection 43 to an adjustable box 45 with a port 44 controlled by the edge of the web 4. The piston 38 is provided with a small orifice 40 which provides communication between its two sides and balances the degree of suction when the port 44 is closed by the edge of the web as shown, the piston 38 being in its lowest position, the valve 37 closed, and the piston 30 also in its lowest position. Under these conditions pressure fluid is admitted to the cylinder 11 to move the piston 12 and the roll 3 to the right to uncover the port 44. When the port 44 is uncovered the piston 38 is lifted and the valve 37 opened and suction applied to the piston 30 which is lifted and which actuates the valve 17 to reverse the flow of pressure fluid to the piston 12 and move the roll 3 to the left to cover up the port 44 again. The edge of the web 4 is thus maintained between the sides of the port 44. A valve 16 is provided to byepass the ends of the cylinder 11 when the automatic guiding is not required, as in the initial threading up of the machine.