GB805306A - Improvements in apparatus for detecting critical values of feed-rate of yarn or the like material - Google Patents

Abstract

805,306. Yarn feeding mechanism. SOC. D'APPLICATIONS GENERALES D'ELECTRICITE ET DE MECANIQUE. Jan. 2, 1956 [Feb. 3, 1955], No. 18/56. Class 120(2) [Also in Groups XVI and XXXVII] Apparatus for detecting an upper or lower critical feed-rate of yarn &c. cornprises a pulley driven by the material and rotationally mounted on an electrically conducting spindle but insulated therefrom, the spindle and the pulley being connected in an electric circuit, centrifugal weights located in a recess of the pulley and opposed by spring means and electrical contacts operated by the weights for breaking or making electrical connection between the pulley and the spindles when the pulley speeds reaches an upper or lower critical value As shown a pulley 1 is supported for free rotation on a fixed shaft 4 but is insulated therefrom and has a disc brake 5 applied to its upper surface by means of a spring 6 the braking effect of which is varied by a nut 7. The V-groove 2 of the pulley may be provided with a loose friction lining or may be roughened in some way to ensure a grip of the yarn in the V. A pair of centrifugal weights 20 pivotally mounted at 21 in a recess 19 in the top of the pulley carry electric contacts 22 engageable with the shaft 4. The contacts 22 may be so wired as to give some indication of a lower critical speed or a higher critical speed or both thus enabling lower and upper limits of feed rates to be detected and appropriate automatic correcting action effected. Such action may be for the acceleration of the feed rate when the pulley speed falls below a critical value or to stop the machine. Detection of an upper limit of feed rate may be followed by deceleration of the feed rate &c. To ensure good contact of the yarn with the feed pulley a guide as shown in Fig. 3 may be provided.