GB844806A - Improvements in apparatus for controlling the feed rate of yarn and the like for textile and the like machinery - Google Patents

Abstract

844,806. Yarn &c. feed rate control devices. SOC. D'APPLICATIONS GENERALE D'ELECTRICITE ET DE MECANIQUE. Feb. 27, 1958 [April 9, 1957], No. 6363/58. Class 120(2). [Also in Groups XVI and XXXVII] Apparatus for controlling the feed or delivery rate of yarn &c., comprises an electrically conducting pulley driven by the yarn and connected to one terminal of an electrical circuit controlling the yarn feed and in which radially movable switch-actuating elements, subject to centrifugal force, are adapted to displace by their radial movement, an axially displaceable contact member electrically connected with the pulley to make or break contact with a central fixed contact member insulated from the pulley and electrically connected to the other terminal of the electric circuit, the radially movable elements not themselves constituting switching contact members or essential elements of the current-conveying circuit. The embodiment shown is mounted on a metal base plate 35 connected to one lead - of an external electric circuit. Secured to the base plate but insulated therefrom is a fixed spindle 30 connected to the other lead + of the electric circuit. A pulley 24 which is engaged by a moving yarn or the like is mounted by ball bearing 37 on the insulating sleeve 33 and is electrically connected through the bearing and a metal sleeve 36 with the plate 35. The pulley has a frusto conical depression in which are formed shallow radial grooves 25 locating balls 26 constituting the centrifugal elements. Balls 26 engage the underside of a disc-like contact member 27 having a central boss 29 which is normally engaged with the domed head of spindle 30 by means of an axial spring 31 retained by a metal cap 32. When the feed rate of the yarn and hence the rotational speed of the pulley exceeds a predetermined value the balls 26 ride up the grooves 25 and by their engagement with the downwardly bent edge 28 of the member 27 press the latter upwards to break the contact between member 27 and spindle 30. By suitable arrangement the same result can be obtained with radial movement of the balls inwards thus setting a lower limit to the feed rate. A tension regulating brake constituted by a plate 40 fixed to the lower face of pulley 24 and a friction pad 39 pressed against plate 40 by a spring 38 is provided. The spring 31 may be replaced by gravitational or magnetic means. Specification 805,306 is referred to.