GB264813A - Improvements in and relating to wrapping friction control - Google Patents

Abstract

264,813. Bethlehem Steel Co., (Assignees of Nieman, H. W.). Jan. 22, 1926, [Convention date]. Clutches, friction.- Relates to coil, band, or linked-segment clutch controlling-means of the type in which the clutch acts only while a control rope 17, Figs. 1 and 2, is actually being pulled or a spindle 58, Fig. 8, is being rotated, and usually through a limited stroke ; the load 18, Figs. 1 and 2, may be attached directly to one end of the coil &c. so as to be moved rectilinearly or a rotating shaft 47, Figs. 7 and 8, may constitute the driven element. According to the invention, springs 19, 38, 39, 62, or 74, weights, or the equivalent, are connected approximately tangentially at intermediate points in the coils &c. to act in opposition to the pull of the control member for the purpose of overcoming the effects upon the power required to actuate the control rope &c. of factors other than the friction between the coil and the constantly-rotating driving drum and of changes in the coefficient of frictions and in the load. In the form shown in Figs. 1 and 2, a band 10 is coiled around a constantly-rotating drum 16, opposite ends being connected to the control 17 and the load 18, and a spring 19 is connected to a pin 20 in the single strand 13 of the band and to a point 21 of the framing, or, in a modification, to the cross-bar 14 of the band. The spring may be of the blade type acting on the pin 20 and on pins in the double strands 11, 12 of the a band. In the construction shown in Fig. 6, band increasing in breadth from the control to the load end 37 is used with two springs 38, 39, preferably varying in strength in proportion to the breadth of the band. In a modification of this construction, a rope of constant diameter is used with three springs of equal strength. As shown in Figs. 7 and 8, a lever 52 is interposed between the two lengths of clutch band employed. The constantly-rotating driving drum 43 is adapted to be engaged by expanding and contacting bands 48, 54 connected at their extreme ends respectively to a pin 49, secured on arm 50 keyed to a rotatable shaft 47 connected to the load, and to a pin 56 on an arm 57 passing loosely through a slot in the shaft and secured to a rotatable control spindle 58. The adjacent ends of the bands are connected to opposite ends of a lever 52 pivoted on the load arm 50 and connected thereto by a spring 62. Movement of the spindle 58 in a counter-clockwise direction tightens the band 54 on the drum 43 and thus expands the band 48, In the form shown in Fig. 9, two contracting bands 64, 65 connected respectively to the control spindle 70 and load arm 67 are used, both bands being connected to a point on a lever 71, which is pivoted at the point 72 to the arms 67 and also connected thereto by a spring 74. Specifications 246,847 and 264,148 are referred to.