GB842221A - Improved means for giving a variable rotational movement to a part - Google Patents

Abstract

842,221. Converting rotary into oscillating motion; variable-speed ratchet gear. SIMON Ltd., H. Aug. 15, 1958 [Aug. 30, 1957], No. 27347/57. Classes 80 (1) and 80 (2). A pulley or chain wheel 15 is osoillated with a variable amplitude by one or more lengths of cord or chain o actuated by a pulley 10 freely mounted on an eccentric on a rotating driving shaft y, one end of the cord being attached to a spring 18 while the other end is attached to the end of a stationary arm q which is adjustable about a pivot r to vary the angle to which the cored is wrapped around the pulley 10, and hence vary the amplitude of oscillation of the wheel 15. The wheel 15 may be coupled to a driven shaft 17 through a one-way clutch to produce variable-speed intermittent rotation. The cord or chain may be secured to the wheel 15 itself, instead of to the spring 18, alternative resilient restoring means being then provided. As shown, the arm q is adjusted about its pivot r by rotation of a hand wheel v carrying a sprocket engaging a length of chain on a quadrant s secured to the arm q. In a modification the arm is adjusted by a lever rotatable about the axis of the shaft y and having a pin-and-slot connection with the arm. In the embodiment shown two chains (only one of which, o, can be seen in Fig. 3) run side by side and are fixed to side by side wheels coupled by respective one-way clutches to the shaft 17, the chains passing around pulleys which are freely mounted on respective eccentrics on the shaft y. The eccentrics are out of phase by 180 degrees so that the respective movements imparted to the shaft 17 supplement each other.