GB1183741A - Improvements in or relating to Textile Shearing Machines. - Google Patents

Abstract

1,183,741. Shearing fabrics. S.M.I.T. SOC. MACCHINE PER L'INDUSTRIA TESSILE S.p.A. 14 Sept., 1967 [15 Sept., 1966], No. 42045/67. Heading D1S. Apparatus for automatically displacing away from fabric 1 being sheared a shearing device 7 of a textile shearing machine comprises means 5 arranged to act over the whole width of the fabric to detect thickened portions of the fabric 1 approaching the device 7, means 10, 12 operable by the means 5 to displace the device 7 away from the fabric I following detection of the beginning 3' of such a thickened portion 3 and to return the device 7 following detection of the end 3" of the portion 3, and timing means which delays operation of the means 10, 12 on detection of the beginning 3' and the end 3" and which automatically reduces the delay period for increase in speed of the fabric. The fabric 1 passes over an idler roll 2 having a non-slip coating and between idler rolls 4, 5, the roll 5 being mounted perpendicular to the longitudinal edges of the fabric 1 and movable away from the roll 4 by a seam 3 which is inclined to the fabric longitudinal edges. The fabric 1 is pulled over a table 6 on which it is sheared by a bladed rotor 7 carried by a pivotable arm 8 having an adjusting screw 9 following a cam 10 mounted on a shaft turnable by an arm 11 driven by a pneumatic piston-and-cylinder device 12 controlled by a valve 13. In operation, the roller 5 is raised when it detects the beginning 3' of the seam 3 and operates a switch 14 to close a lower pair of contacts 14' to energize an electro-magnetic clutch 15 and, by closing a secondary contact pair in a control box 16, to prepare for the energization of an electromagnetic clutch 17 which will occur on lowering of the roller 5 and consequent closing of an upper pair of contacts 14" of the switch 14 and thus deenergization of the clutch 15. The clutch 15 transmits the motion of the roll 2 to the shaft of a timing cam in the box 16. The rotor 7 is lifted when this timing cam has turned through an angle allowing the greatest practical approach of the beginning 3' to open the circuit of the control solenoid 18 of the valve 13. When a second timing cam connected to the clutch 17 has turned through an angle allowing the end 3" to reach a point immediately beyond the table 6. This latter cam closes the circuit of the solenoid 18 to lower the rotor 7.