GB974617A - Improvements in clutch controlled drives - Google Patents

Abstract

974,617. Controlling clutches. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. March 1, 1961 [March 11, 1960], No. 8730/60. Headings F2D and F2L. A ratchet gear clutch device for chainconveyers etc. comprises a continuously rotating driving shaft 1 fast with a ratchet wheel 3 and rotatably supporting a driven disc 5 upon which pivots at 8 a pawl 9 biased by a spring 10 to engage the ratchet wheel, a cam follower roller 11 on the pawl running over the inner periphery of a drum 4 rotatably mounted upon the driving shaft and biased by a spring 12 so that a radial arm which it carries engages an adjustable stop screw 13. In the position shown, a swell point 14 in the drum 4 receives the cam roller 11, and the spring 10 biases the pawl 9 out of engagement with the ratchet wheel. By momentarily energizing a solenoid 22, or by other means, a link 17 is slidden downwardly and through a lever connection turns a bellcrank 18 against spring bias to withdraw a detent pawl 20 from engagement with a notch on the periphery of the driven disc 5, accordingly freed for rotation. Following disengagement of the detent pawl 20, the lost motion in connection 16 between the link 17 and the drum 4 is taken up, and continued downward movement of the link turns the drum against the bias of its spring 12, so that the cam roller 11 moves out of the dwell point 14 and the pawl 9 is turned to engage the ratchet wheel 3 for the transmission of drive. When the solenoid 22 or its equivalent is de-energized and released, the driven disc 5 rotates until the cam roller 11 engages an inner cam surface 15 in the drum 4 and reenters the dwell point 14, when the pawl 9 is disengaged from the ratchet wheel 3 and the detent pawl 20 re-engages the notch in the periphery of the driven disc 5, which is accordingly stationed. If, however, a series of impulses is fed to the solenoid 22 &c., the driven disc 5 continues to rotate with the driving shaft 1. Adjustment of the stop screw 13 determines the angular rest position of the drum 4 about the axis of the shaft 1, and hence the angle of rotation through which the driven disc 5 is in positive engagement with the driving shaft 1 during a single revolution. In the form shown, the driven disc 5 is fast with an output sprocket 21. As a modification, more than one dwell point and more than one notch for the detent pawl in the disc 5 may be provided.