Patent GB-190323871-A (GB)
Title: Improvements in Needle Threading Attachments for Sewing Machines.
Inventor: BATTEY SUMTER BEAUREGARD
Filed: 1903-11-03
Granted: 1903-12-03
Abstract: 23,871. Battey, S. B. Nov. 3. Needle-threaders; sewing - machines, governing n e ed le thread in; threadguiding eyes; thread-cutters ; needle-holders.- Relates to a needlethreading device for sewing - machines, arranged to thread the needle automatically i n case the thread breaks. The needle A is secured to a needle-bar B, which vibrates in a head B' of an arm B<2>, and is pivotally connected by a rod B<3> with a disccrank C driven in the usual manner. An arm F on the front of the head B<1> is arranged on the side of the needle A, and has a longitudinal guideway F<1>, in which slides a crosshead G' carrying a split shank ; this has clamped in it a plunger G, which, in the case of the thread E breaking, pushes it through the eye of the needle when the needle-bar moves to its highest position. To reciprocate the crosshead G<1> rapidly, an eye-bolt G<3>, Fig. 1, which holds the plunger in place in the crosshead G<1>, is provided with an extension pin, engaged by a fork on the lower end of a lever H, the pin-like upper end H<3>, Fig. 5, of which is engaged by a cam device on the crank C. This device consists of a V-shaped groove C<2>, Fig. 16, and a lever-cam I, fulcrumed at I' on the face of the crank C, and having one end provided with a V-shaped offset I<2>, which passes in front of the groove C<2>, and engages the end H<3> of the lever H, imparting to it a quick swinging motion, as soon as the wrest-pin of the crank C moves into its uppermost position as shown in Fig. 1. A projection I<3> on the other end of the lever cam I is adapted to be engaged by the end J<1> of a lever J, pivoted at J<2> on the head B, the lower end J<3> of the lever engaging with an oblique cam groove J<4> in a cam J<5>, mounted on a shaft J<6>. The shaft J<6> carries an arm J<7> through an eye J<8> of which the thread E passes and exerts an upward pull on the eye J<8> so as to hold the cam J<5> normally in the position shown in Fig. 1. As soon as this pull is relaxed, as when the thread breaks, the cam J<5> is caused to swing by the pressure of a light spring J<9> on the shaft J6 imparting a swinging motion to the lever J, and thereby actuating the lever cam I. When the thread is pushed by the plunger through the eye of the needle, it forms a loop, which is caught by the free end of a thread-retainer, the latter being in the form of a horn K, Fig. 11, which receives a limited downward swinging movement from the lever H, as the latter moves from left to right, by having an L-shaped shank K<1> on the horn K secured to a shaft K<2>, journalled in the arm F, the shank being engaged by a cam arm H<4> secured to the lever H. The loop of the needle thread is held by the horn K until the needle moves into its lowest position, when a pin B<4> on the needle-bar engages the forward end K<3>, Fig. 11, of the shank K<1>, and swings the horn K back to its former position. For fast-running machines, the thread-retainer is of the form shown in Fig. 8, and consists of two clamping-jaws 0, 0', the lower one O<1> projecting from the lower end of a bracket O<2> bolted to the head B'. The other jaw 0 is held on an adjustable arm O<3> bolted to the arm O<2>, the jaws 0, O<1> being normally held together by the pressure of a spring O<6> on the upper end of the arm O<3>, which also has a lug O<7> adapted to be engaged by the rear end of the pin B<4>, Fig. 5. When the needle-bar rises, a loop of the thread, and the free end of the plunger G, pass between the jaws 0, O<1>, and, as soon as the plunger commences to return, the jaws 0, O<1> are closed by the spring O<6> so as to clamp the loop between them. In case the automatic thread-controlled device becomes out of order, the lever cam I may be actuated by a handle P, Fig. 5, mounted on a vertical shaft P<1>, which carries an eccentric-pin engaging a projection I<5> on the lever cam I, the movement of the latter being limited by shoulders on the handle P abutting on a fixed pin at the top of the head B'. The thread passes from a spool through an eye Q, Fig. 5, on the head B<1> to a tension-device R, and thence through the eye J<8> and up through the eye D' on a thread arm D provided with a friction roller which engages with a peripheral cam groove on the hub of the crank C, then through the eye E<1> to a preferably curved groove F<2>, Fig. 11, in the front end of the guideway F<1>. A guide L, Fig. 11, extends across the top of the groove F<2>, and the front of the guideway F<1> is a fixed horn L<1> to permit the operator to pass the thread into the groove F<2> ready to receive the plunger G, which is preferably slightly recessed at its forward end. The thread is kept stretched vertically in the groove F<2> by spring clamping- arms N, N<1>, Fig. 6, secured to the underside of the guideway F<1>, the free ends of the arms N, N' being curved outwardly under the groove F<2>. If the thread-controlled device is out of order, the thread passes from the tension-device R, through another tension-device R<1>, and then up through the eye D<1> instead of through the eye J<8>. The arm B<2> carries a knife S for cutting the thread when necessary.