GB264653A - Improvements in or relating to mechanism for transmitting rotational movement - Google Patents

Abstract

264,653. Black, W. C. Jan. 12, 1926. Coal-cutting machines.-Mechanism for transmitting rotary motion, applicable to control the swinging motion of the cutting members in coalcutting and like machines, embodies ratchet gearing in which a pivoted pawl carried by an oscillatory member is normally held out of action by a spring and is caused to engage the ratchet wheel when and only so long as pressure is applied to a control handle. A slotted lever 6 on a pivot 7 is oscillated by a driving crank 3 and carries between jaws 9, 10 a loosely pivoted toothed segment 8 meshing with a similar toothed segment 12 loosely mounted on the shaft 2 to be driven. The segment 12 is hollow to enclose a square toothed ratchet wheel 11 fixed to the shaft 2 and carries a double-ended pivoted pawl 14 integral with which is a tongue or lug 15 engaging a spring 16 on a loosely mounted controlling handle 18 so that the pawl is normally kept out of engagement and the lever 6 oscillates idly. When the handle 18 is pressed in either direction the pawl is tilted and through contact with stops 19, 20 the segment 12 is rocked until the segment 8 abuts against one of the jaws of the lever 6 whereupon rotation is imparted to the shaft 2 so long as pressure is maintained on the control handle 18, the direction of rotation being opposite to the direction of manual pressure independently of the direction of rotation of the driving shaft 1. The relative radii of the toothed segments may be varied, the segment 8 may be integral with the lever 6, or two or more toothed segments controlling different shafts may be associated with the same oscillatory lever. The shafts 1, 2 may lie in different planes. In a modification they are at right angles and the segments 8, 12 are formed with bevel teeth.