GB1170738A - Improvements relating to Textile Machines - Google Patents

Abstract

1,170,738. Carding engines. JAMES MACKIE & SONS Ltd. 24 April, 1967 [29 April, 1966], No. 19029/66. Heading D1N. In an arrangement for maintaining oscillations of a stripping knife 2 for a textile machine, the knife is supported by a tubular shaft 1 containing a torsion bar 9, and a driving mechanism produces mechanical impacts acting at intervals on surfaces 21 of arms 20 connected to, and extending radially from, the shaft. The mechanical impacts may be produced by pulses of compressed air applied to a flexible diaphragm 22. The shaft preferably has two laterally extending arms which each include a diaphragm supplied with compressed air from a single rotary valve member 28. The magnitudes of the impacts are controlled by a pneumatic control circuit 40 in dependence of the amplitude of oscillation in order to maintain the amplitude substantially constant. The control circuit 40 includes a pressure regulator 41 in which a throttling valve 47 is acted on by subsidiary air pressure in chamber 64 acting on a diaphragm 65 which in conjunction with a spring 48 tends to open the valve to increase the pressure of the main compressed air supply through conduits 42 and 43 to. the valve member 28. The subsidiary air pressure is adjusted by an interrupted air flow signal device 53, 54 controlled by an interrupter 52 oscillating with the shaft. The greater the amplitude of the oscillation the less long is the air flow interrupted and the greater is the subsidiary pressure, and vice versa. Alternatively the mechanical impacts may be produced by (a) bursts of compressed air directed directly onto the arm, in which case the arm can take the form of a vane operating in a closed housing or (b) a striker in the form of an electrically or mechanically operated cam.