GB163132A - Stop-motion for sewing machine - Google Patents

Abstract

163,132. Fairweather, W. C., (Hamel Shoe Machinery Co.). Feb. 16, 1920. Sewing-machines; starting and stopping gear.- A sewing-machine is equipped with a friction clutch drive by means of which the working speed can be varied and a positive clutch which, in the stopping operation, is put into action and brings the machine up to full speed prior to the machine being positively stopped. A pivot in the needledriving mechanism is moved in the stopping operation to prevent the threading of the needle in the last cycle. During the normal running of the machine, a treadle actuated rod 13 by means of a bowl 19 presses upon a lever 21 and forces the clutch surfaces 11 together with a pressure determined by the desired speed of the machine. A latch 52 projects over the end of the lever 21 and prevents an upward movement sufficient to open the clutch 11 and also engages an arm 50 of a stop lever 40 and holds it from action. To stop the machine the treadle is released and a spring 93 begins to raise the rod 13. A latch 32 then slips into a notch in the rod and holds it until withdrawn by a cam 33 at a predetermined point in the rotation of the machine shaft. When the latch is withdrawn, the rod 13 is moved upward by the spring 93 and a bowl 51 turns the latch 52 so as to release the lever 21 and the stop-lever 40. A spring 85 thereupon turns the lever 21 so as to open the clutch 11 and also to move the part C until the end 27 positively engages the outer member 39 of a positive rollclutch by which the machine is then driven at full speed. At the same time, the plunger 49 of the stop-lever first rides against the face cam 37 and then passing on to the periphery is momentarily depressed by a high part of it and afterward released. During the depression, an arm 54 on the plunger passes under a catch 63 and when the plunger is released by the cam and forced upward by its own spring, the arm 54, in engaging the catch 63, forces a rod 59 upward with it. This rod rotates a lever 58, applies a brake 36 to stop the machine and returns the part C of the main clutch into a middle position in which it is entirely disengaged from the machine shaft. Operative connections with other machine parts. A lever in the needle-driving mechanism is pivoted upon an eccentric part of a shaft 17. When the rod 13 rises to stop the machine, rack teeth upon it rotate the shaft 17 and the eccentric pivot and prevent the needle from moving into the threading position. The rod 59 is connected to a lever 60 by which the needle-thread is removed when the machine is stopped.