Abstract: This relates to the provision of a stall shutdown circuit for a brushless direct current motor wherein energization of the windings of the stator of the motor is controlled by transistors. By providing a stall shutdown circuit for shutting down power to the transistors when a stall condition exists, the capacity of the power supply transistor may be reduced to one-third of that presently required, thereby greatly reducing the cost of the motor. The brushless direct current motor utilizing the stall shutdown circuit of the present invention is particularly useful in a textile machine such as a take-up device where it is necessary to stop a spindle to doff and don yarn packages.

Abstract: This invention relates to a take-up machine utilized in conjunction with the production of fiber or yarn wherein the product fiber or yarn, as it is produced, is wound onto spools or tubes. A control is provided for varying the speed of an electric motor which drives a spindle on which the tube or spool is mounted. This control is actuated by the position of a compensator arm which is connected to a core of a linear voltage differential transformer which, in turn, controls current flow through an NPN power transistor. The power transistor, in turn, controls current flow through a rectifier having one circuit for each of three windings of a three-phase AC motor, thereby controlling the speed of rotation of the motor.

Abstract: Apparatus for automatically controlling movement of an area of material with respect to a work point in a machine in which revolvable control means continuously engages the region of the material in front of the work point and in close proximity to that point. An exemplification of the invention is in a sewing machine in which pressure exerting means urges revolvable control means into guiding engagement with that front region in the fabric as the material advances over the support toward the work point, for guiding and smoothing the fabric material and enabling a wide variety of stretchable as well as stiff fabrics to be guided quickly, accurately and effectively.