GB191114164A - Improved Driving and Stopping Devices for High-speed Machines. - Google Patents

Abstract

14,164. Denne, M. T. June 14. S e w i n g - machines; stopping-gear, non-automatic.-Relates to cone and o t h e r friction clutches and operating- gear in which the first part of the movement of the operating-treadle moves one clutch part quickly into complete frictional contact with the other part, further movement of the treadle gradually moving the second part away from the first. Secured to the driven shaft 10 is a disk 8 provided with an arm 9. Turning with a small amount of free motion on the hub of the disk 8 is another arm 11, which is secured to a quick-threaded nut 12 engaging with a thread 13 on the friction cone 14, which is connected to tEe disk 8 by a rod 45. A spring 16 tends to press the cone 14 into engagement with the driving-pulley 15, at the same time turning the arm 11 until the arms 9, 11 are placed as shown in Fig. 2. An arm 18 is provided with a notch 19 and turns on a pivot 20 on the piston 21 of a dash-pot 22, which may contain a spring 43. A spring 24 bears on a lug 23 on the arm 18 to swing the arm out of the path of the arms 9, 11. The arm is kept normally in the inposition, however, by a lever 26, which is acted on by a spring-pressed rod 25 connected to the treadle-rod 33 bv a bell-crank lever 31 secured to a shaft 32. Partial depression of the treadle moves the lever 26 so that the arm 18 is swung out by the spring 24, releasing the arms 9, 11 and allowing the spring 16 to move the cone 14 suddenly into engagement with the pulley 15 to transmit the full power. The shaft 32 is geared to a crank-shaft 39, Figs. 1 and 5, which has cam projections 38 adapted to engage a loose collar 36 with cam recesses 37, on which bears a nut 35 secured to the driving-pulley 15 and tending to be pressed outwards by a spring 34. Further depression of the pedal rotates the shafts 32, 39 so that the projections 38 engage the recesses 37, and the spring 34 moves the pulley 15 gradually away from the cone 14, further movement of the cone being prevented by a stop. The shaft 32 carries a pinion engaging a rack carrying a brake shoe 40, which engages the cone 14 when the pulley 15 has been quite disconnected from the cone 14. As the pedal is released, the pulley 15 is moved back into contact with the cone 14. Finally the lever 26 moves the arm 18 back into the path of the arms 9, 11. The arm 11 then engages the notch 19, the shock being absorbed by the dash-pot 22, and the momentum of the moving parts brings the arm 9 also into the notch and moves back the cone 14 through the action of the screws 12, 13. The rebound of the piston 21 may be used to remove the loops from the needle-bar.