Patent GB-1059404-A (GB)
Title: Ratchet device
IPC: B66D5/00
Filed: 1964-01-31
Abstract: 1,059,404. Winding apparatus. EASTER MARINE Inc. Jan. 31, 1964 [Feb. 12, 1963], No. 4254/64. Heading B8B. [Also in Division F2] A ratchet mechanism for a capstan or winch (Figs. 1-4, not shown), comprising a cable drum (25) rotatably mounted on a fixed post (39) enables the drum (25) to be positively driven in either direction, or to rotate freely under the control of a friction brake. A cylindrical easing (28) integral with the drum (25) carries a hand wheel (29) and is formed with interior ratchet teeth (36). A cover-plate (12) is bolted to a fixed cast frame (37) which carries the ratchet mechanism within the casing (28). The support (17) of a foldable operating lever (13) is secured to a shaft (15) journalled in spaced sleeves (46) integral with the frame (37). Two pawls 54, 55 are welded to the exposed middle portions of respective pins 53 located in axial bores in the shaft 15, rivets 56, 59 near the free ends of the pawls engaging in slots 58, 61 of links 57, 62 both pivoted at 60 to one arm of a bell-crank 63 pivoted at 44 to the frame 37. The other arm 64 of the bellcrank has a projection 65 engageable with a cam 51 pivoted at 48 to the frame 37 and carrying a selection lever (52) above the coverplate (12). A crank 68, also pivoted at 44, has an arm 69 carrying a lug 74 which may engage fingers 75, 76 on the pawls 54, 55 respectively, an arm 71 engageable by the cam 51, and an arm 72 carrying a stop 77 engageable with a brake (81) pivoted to the frame (37) and having a shoe (82) for frictional engagement with the inner surface of the casing (28). A torsion spring 73 acts on rivets 67 of the links 57, 62 to urge the pawls 54, 55 into engagement with the ratchet teeth 36, and on the crank 68 to urge it anti-clockwise (Fig. 5). To take up a cable secured to the drum (25) the selection lever is set in a " pull " position, in which a recess 66 in the cam 51 engages the projection 65 on the crank arm 64 to move the links 57, 62 to a position allowing the pawls 54, 55 to engage the ratchet teeth. The lever (13) is rocked to oscillate the shaft 15 so that the pawls act on the ratchet teeth alternately to turn the drum (25). When the loaded cable is held stationary, both pawls engage the ratchet. Fig. 5 shows the cam 51 in a " load release " position in which the arm 64 is freed, allowing the spring 73 to turn the bell-crank 63 clockwise so that as the lever (13) is rocked the pawl 54 is lifted clear of the ratchet teeth while the pawl 55 is backed down under the cable load, and vice versa, in alternation, to pay-out the cable. With the cam 51 in a "rope release' position (Fig. 6, not shown), the arm 71 of the crank 68 is allowed to rotate anti-clockwise under the action of the spring 73, so that when the loads on the pawls are removed by moving the lever (13) first in one direction and then in the other, the lug 74 engages the fingers 75, 76 to draw the pawls out of engagement with the ratchet teeth. The drum (25) is then free to rotate, and is controlled by urging the lever (13) and shaft (15) clockwise (Fig. 6) to force the crank 68 anti-clockwise, causing the stop 77 to urge the brake shoe (82) against the casing. For this action, the finger 75 includes a recess (83) to engage the lug 74.