Patent GB-190225936-A (GB)
Title: Improvements in and relating to Sewing Machines
Inventor: BROOKES ALFRED GEORGE
Filed: 1902-11-25
Granted: 1903-04-30
Abstract: 25,936. Brookes, A. G., [Reece Buttonhole Machine Co.]. Nov. 25. Buttonhole-sewing machines buttonholes, barring; needle-bars, vibrating laterally.-Relates to machines for overstitching the edges of buttonholes and the like, and is adapted to produce straight buttonholes. The pivoted gate C' by which the needle-bar is vibrated laterally for both the depth and barring stitches, is oscillated from a cam on the main shaft A' by connections including a slotted arm and block sliding therein, the block being adjustable in the slot, to alter the oscillation of the frame c<1>, by means of a rod C<10> controlled by a lever D', as described below. The needle-bar is mounted in the gate C' by a single long sleeve, so that a short needle-bar can be used. The work clamp E' is carried by a frame D pivoted vertically above the needle-bar by a universal joint comprising the pins D<7>, D<9>. The work clamp is curved as shown, and moves on a correspondingly-curved throat plate. The longitudinal feed of the work clamp is effected by a nut F<3> of a screw F'. Special means are provided for rotating the screw in one direction and then in the other, with intervals of rest for the sewing of the barring-stitches. These means comprise a reversible friction-ratchet feed, Figs. 12 and 13, and means for controlling the same. A segment a<1>, oscillated from the main shaft, and loose on the screw shaft, has two oppositely-directed faces 2, 4, between which and the flange of a disc d fixed to the shaft, a gripping-pin c<9> is adapted to engage to rotate the screw. Between the faces 2, 4 is a face 3, on which the pin c<9> cannot grip. The pin c<9> is held over the required face 2, 3, or 4 bv means of a carrier c<1>, capable of being rotated slightly relatively to the segment a<1> by an axiallymovable tongue b' having three cam-faces 5, 6, 7, Figs. 12 and 21, which engage a shoulder 8 on the carrier c'. The movements of the tongue b<2> to control the position of the gripper c<9>, are obtained from a lever b<9>, which is moved intermittently by a right and left handed worm e on the shaft A'. The free end of the lever b<9> is under the worm e, and carries two pins e', e<3>, one adapted to engage the right and the other the left hand part of the worm. On starting the machine from the initial position shown, the screw F' moves the nut F<3> and work clamp to the left, until an adjustable stop 9<1> carried by the nut, engages a latch and allows the pin e' to rise and engage the worm e. The lever b<9> and tongue b<2> are then moved to the left by the worm, first stopping the screw F<4> and then reversing it. On the return movement of the clamp, the stop g releases the pin e<3>, and the lever b<9> and tongue b<2> are returned to their initial positions. As the lever b<9> completes this movement, a projection carried by it releases the stop mechanism to cut the buttonhole and stop the machine. The lever b<9> carries at its free end a cam-block formed with two cams. By one of these the work clamp is positioned laterally, and by the other acts on the lever D' to cause either barring or depth stitches to be made. Chain - stitching machines; overedge - stitching machines ; needle - driving. - The needle - bar is reciprocated from a crank on the shaft A' by a linkage which includes a toggle connection, so that the needle makes two reciprocations for every revolution of the shaft. The looper is oscillated by a toothed segment and pinion, and makes one complete oscillation to every two reciprocations of the needle. It has two oppositely-directed points r, r<1>, Figs. 17 and 20, and a slot r' for the needle to enter. The needle loops are taken by the points r, r<1> alternately, the one loop being spread and retained by the enlarged body of the looper while the next is passed through it, Fig. 17. Stopping-gear; stopping, automatic ; buttonholes, cutting.-The belt-shitter arm h<8>, shown in plan in Fig. 4, is fixed on a sliding rock-shaft H". To start the machine, the shaft H" is moved to the left against the action of a spring h<7>, thus shifting the belt from the loose pulley A<7> to the fast pulley A<5>, and is engaged by a retaining-catch h<2> of a lever h<3>. On the completion of the stitching, as described above, a projection carried by the lever b<9> moves the lever h<3> so as to release the shaft h<12>, which is then returned to the right by its spring h<7>, A toe carried by the arm h<8> is now over a cam m<2> fast on the shaft A<4>, and, as the shaft continues to rotate, the cam m<2> raises the arm h<8> against the thrust of a spring rod m<3>, thus causing a pin h<7> on the arm h<8> to depress the cutter lever H<1>. The high part of the cam m<2> terminates in a locking- slot 40, and on the depression of the arm h<8> due to its toe engaging the slot 40, the cutter lever is raised, and a projection E<10> carried by its extension H<3> engages a catch E<9> of a link E<8>, and thereby operates a lever to open the work clamp.