GB683079A - Improvements in sewing machines - Google Patents

Abstract

683,079. Sewing-machines. EISENBEISS, J. F. R. March 2, 1950 [March 2, 1949; Aug. 18, 1949; Feb. 9, 1952], No. 5346/50. Drawings to Specification. Class 112. In order to avoid the need for gearing to convert rotary to reciprocating or oscillating movement the needle-bar, feed-mechanism, and shuttle or looper are actuated by solenoids controlled by the movements of the needle-bar. Since the standard and arm contain no mechanism, the frame may be jointed in various ways to provide for placing the head in various positions or for moving it clear of the work, or it may be formed with interchangeable sections of different sizes. Straight needles, driving.-In the embodiments described the needle-bar is moved downwards by a solenoid and raised by a spring, the movement being controlled by an air dashpot or by electromagnetic damping means. If the needle-stroke is long, the solenoid may be divided into successively-energised sections. If the frame is constructed so that the arm or head can be moved out of operative position, the needle-bar solenoid circuit may include a contact which is broken when the head or arm is moved. Lock-stitching by shuttles.-In one form, a shuttle is carried in an arcuate holder oscillating about a pivot and provided at each end with an iron core acted on by a fixed solenoid; the solenoids are energised alternately, through contacts actuated by the movement of the holder, so that the shuttle makes a single stroke during each upstroke of the needle-bar. In another form the shuttle oscillates on a spindle geared to a relatively large wheel to which are connected respectively a solenoid-actuated rod and a return spring. Feed by dogs.- The usual feed-dog is connected to a solenoid which produces its workadvancing movement. Frames.-The head may be vertically adjustable on the arm or pivotable about an axis parallel to the arm. The standard may be provided with a hinge or hinges arranged so that the arm can be swung upwards in a vertical plane to facilitate the insertion of work and/or swung bacliwards about an axis parallel to itself to incline the needle, and it may be divided on a horizontal plane, the upper part, with the arm, being movable about a vertical axis and adjustable vertically on that axis; contacts are provided to break the needle-operating circuit when relative movement of the frame parts carries the needle out of operative position. The arm and the base may be divided at corresponding points so that a standard with longer arm and base portions may be substituted for the existing one to accommodate large work.