US 3670589 A
A multiple-speed winch having a plurality of independently rotatable pinions coaxial with a drive shaft, drive linkages of varying mechanical advantage connecting these pinions to the winch drum and a shaft engager for engaging a selected pinion to the drive shaft. The shaft engager includes drive cams associated with the pinions and mounted for movement between an extended position which prevents relative rotation of pinion and shaft and a retracted position which permits rotation; selective extension of the drive cams causes the shaft to drive selected pinions.
Claims available in
Description (OCR text may contain errors)
United States Patent Carter [4 June 20, 1972 41 WINCH [$6] nae-mm cm  Inventor: John Henry Carter, Lincoln, Mass. UNITED TATE PATENTS 73 Assignee; Ammmne Corporation Weston, Mass 3,145,974 8/ l964 Short ..254/l50 R  Filed: May 5, 1971 Pn'mary Examiner-Leonard H. Gerin ] pp No: 140,332 Attorney-Martin Klrkpartnck Related us. Application um  ABSTRACT A multiple-speed winch having a plurality of independently Dlvlslon of Se". NO. Feb. 7, Pat. NO. rotatable pinions coaxial a d ive hah d i e linkag of varying mechanical advantage connecting these pinions to the winch drum and a shah engager for engaging a selected pinion US. Cl. 74/325, 3.54, R to the drive shaft. The engage includes drive cams as. [51 Int. Cl ..Fl6h 3/08, Fl 6d 67/00, 866d 1/30 sociated with the pinions and mounted for movement between  Field of Search ..254/150 R; 74/325; 192/351, an extended position which prevents relative rotation of pinion and shaft and a retracted position which permits rotation; selective extension of the drive cams causes the shaft to drive selected pinions.
3Clailm,7DrawingFigum PATENTEDaunzo m2 SHEET 2 [If 3 WINCH This invention is a division of Ser. No. 799,802, filed Feb. 17, 1969, now U. S. Pat. No. 3,599,937, and relates to a multiple-speed winch.
The primary object of the invention is to provide a winch having a selection of power ratios and provision for changing from one ratio to another rapidly and conveniently even when the winch drum is under load. Another object of the invention is to provide such a winch which, with respect to its hauling capacity and mechanical strength is so lightweight and compact as to be excellently suited for use aboard high-performance sail boats.
The invention features a shaft engaged for transmitting rotary motion of a drive shaft to any of a plurality of independently rotatable pinions coaxial with the shaft, the shaft engaged including a plurality of drive cams each associated with a given pinion and mounted to the shaft for movement from a first extended position engaging the associated pinion and preventing relative rotation between the pinion and the shaft (in at least one direction) to a second retracted position permitting relative rotation, and means for selectively extending the drive cams and thus engaging the drive shaft to selected pinions.
In preferred embodiments, each pinion is associated with a drive linkage connecting it to an independently rotatable winch drum, the drive linkages being of varying mechanical advantage. The choice of the particular drive cams that are extended is controlled by the angular orientation of a rotatable cam-control rod within the drive shaft and coaxial with it. The drive shaft is freely rotatable in the reverse direction with respect to all the pinions (permitting the shaft to be cranked backwards without moving the winch drum, and also permitting the winch drum to be pulled through in the forward direction (e.g. by manually hauling in a line wrapped around the winch drum without rotating the drive shaft or crank). Three pinions are employed, a first (high-speed) pinion directly connected to the winch drum, a second mediumspeed pinion connected to the winch drum through a stepdown drive linkage, and a third low-speed pinion connected to the drum through another step-down drive linkage having a greater step-down ratio. The winch drum is positively prevented from rotating in a backward direction by a basemounted pawl mechanism. The winch drum is forwardly rotatable with respect to the low-speed linkage, providing isolation of that linkage from the drum. For strength and lightness the body of the winch drum is made of cast nylon.
Other objects, features, and advantages will appear from the following description of a preferred embodiment of the invention taken together with the attached drawings thereof, in which:
FIG. 1 is a perspective view of the entire winch;
FIG. 2 is an exploded isometric view of the drive shaft and shaft engager;
FIG. 3 shows diagrammatically the base, drive linkages, and portions of the drive shaft;
FIG. 4 is a sectional view taken on line 4-4 of FIG. 1.
FIG. 5 is a sectional view of the pawl mechanism used to prevent reverse rotation of the winch drum taken on line 5-5 of FIG. 3;
FIG. 6 is a sectional view of the drive shaft, drive cams, cam-control rod, and high-speed pinion taken on line 6-6 of FIG. 3 with the pinion engaged to the drive shaft;
FIG. 7 is a similar view but with the cam-control rod rotated so that the high-speed pinion is disengaged from the drive shaft.
There is shown in FIG. 1 the winch drum 22 rotatably mounted to fixed base 24, the drive shaft 26 concentric with the drum and also rotatable with respect to base 24, crank 28 secured to the upper end of the drive shaft and provided with a handle 30. A similar crank (not shown) can be secured to the lower end of the drive shaft instead of (or in addition to) theupper crank (thus permitting below-deck operation of the winch or two-handed operation).
Concentric with drive shaft 26 is high-speed pinion" 32. (As used herein, pinion" is not intended to be limited to gears alone, but includes any comparable member driven by a rotating coaxial shaft. In the preferred embodiment, highspeed pinion 32 is directly keyed to the winch drum 2 butit may, in other embodiments, be integral with the drum.) Also concentric with drive shaft 26 are medium-speed pinion 34 connected to the drum through a step-down drive linkage (not shown), and low-speed pinion 36 also connected to the drum through another step-down drive linkage (not shown). When high-speed pinion 32 is engaged to shaft 26, each full rotation of crank 28 causes a full rotation of drum 22 with respect to base 24; when medium-speed pinion 34 is engaged to the shaft, 4.25 full rotations of crank 28 are required to produce a full rotation of the drum; when low-speedpinion 36 is engaged to the shaft, 11.05 full'rotations of crank 28 are required to produce a full rotation of the drum.-In the preferred embodiment, the ratio of crank radius to drum radius is about 4.5 to l. Consequently, the winch provides power ratios (mechanical advantages) of about 4.5, 19, and 50.
Referring to FIG. 2,'the shaft 26 is keyed to crank-nut 40 by the pins 42 cooperating with split-bores 43 and is further secured by retaining nut 44. Attachment of crank 28 to cranknut 40 thus holds shaft 26 and crank 28 fixed withrespect to each other. Shaft 26 contains three sets of opposed drive-cam recesses 52, 54, and 56, the two recesses of each set being 180 apart on the drive shaft and the three sets of recesses being axially aligned. Drive earns 62 with associated spring elements 62a are mounted in drive-cam recesses 52 to permit the engagement of shafi26 to high-speed pinion 32. Similar drive cams and spring elements (not shown) are mounted on drive-cam recesses 54 to permit engagement of medium-speed pinion 34, and in drive-cam recesses 56 to permit engagement of low-speed pinion 36. Spacer 35 fixes the axial separation between pinions 34 and 36 and facilitates their rotation.
Cam-control rod is inserted in axial bore 71 of drive shaft 26 and is rotatable within the drive shaft by means of control knob 73 secured to its upper end. The cam-control rod is provided with three sets of opposed cam-control grooves 72, 74, and 76, the two grooves of each set being apart on the cam-control rod and the three sets of grooves being spaced 60 apart. When the cam-control rod is rotated so that grooves 72 register with earns 62, the cams are extended by spring elements 620 (as shown in FIG. 6) and high-speed pinion 32 is rotatably engaged to shaft 26. The earns 62 transmit forward (clockwise) rotation of the drive shaft 26 to internal teeth 33 of high-speed pinion 32, and keys 32a secure the pinion to winch drum 22 so that the drum rotates with drive shaft'26 when crank 28 is forward rotated.
When cam control rod 70 is rotated in additional 60 camcontrol grooves 74-register with the corresponding pair of drive cams, causing the cams to be extended and engaging medium-speed pinion 34 to drive shaft 26. Because cams 62 no longer register with grooves 72, spring elements 62a can no longer extend the cams, and high-speed. pinion 32 is disengaged from the drive shaft (as shown in FIG. 7). Mediumspeed pinion 34, when engaged to shaft 26, drives winch drum 22 through the medium-speed drive linkage, the step-down gear train between pinion 34 and internal ring gear 23 secured within drum 22 (see FIGS. 3 and 4).
A further 60 rotation of cam-control rod 70 causes camcontrol grooves 76 to register with the corresponding pair of drive cams and extension of these cams engages low-speed pinion 36 to drive shaft 26. Both high-speed pinion 32 and medium-speed pinion 34 are then disengaged from the drive control knob 73 (see FIG. 4) to ensure correct angular registration of the selected pair of drive cams with the corresponding cam-control grooves on cam-control rod 70. Control knob 73 can be manually rotated to select the desired mechanical advantage even when the winch drum is under load, provided that no forward torque is applied to crank 28 while changing speeds. (Because of the pawl mechanism previously referred to, backward rotation of the loaded drum is prevented when application of torque to the drum is interrupted.)
FIG. 3 is a diagrammatic representation'of the base, drive linkages, and portions of the drive shaft. Medium-speed pinion 34, when engaged to drive shaft 26, rotates clockwise, causing idler 102 to drive gear 104, which in turn drives internal ring gear 23 (fixedly secured to winch drum 22). When the winch drum 22 is pulled through in the forward direction, gear 104, idler 102, and medium-speed pinion 34 are rotated by the drum, but the rotation of pinion 34 is not transmitted to drive shaft 26 or crank 28. The drive shaft is isolated from the pinion because the corresponding drive carns operate only in a forward direction and slip when the direction of relative shaft rotation is reversed (see FIG. 6). This isolation feature applies similarly to both the high and low-speed pinions 32 and 36. Forward rotation of either of these two pinions is also isolated from the drive shafi and crank. (There is a further, later to be described, isolation between the winch drum and the lowspeed drive linkage.)
Pawl mechanism 110 prevents the winch drum 22 from rotating in a reverse (counter-clockwise) direction. The details of pawl mechanism 110 are shown in FIG. 5. lntemal ratchet 113 is fixedly secured to base 24. Paw] support 111 is coaxial with and secured to the underside of gear 104. Pawls 112 are spring-loaded by spring elements 112a to engage internal ratchet 113, thereby permitting only forward (clockwise) rotation of the winch drum 22 and preventing reverse rotation. This feature is important in that when the winch is under load, the crank 28 can be released without permitting the load to back off and without risk of the crank being accelerated by the load and thus endangering the operator.
Low-speed pinion 36, when engaged to shaft 26, rotates clockwise, driving idler 120 which in turn drives one-way gear 122 clockwise. lntemal teeth 123 of one-way gear 122 engage pawls 125 secured to the underside of pinion 126, causing pinion 126 also to be driven clockwise and to transmit its forward rotation to internal ring gear 23 and thus to the winch drum 22. When the winch is pulled through in a forward direction, the pawls 125 do not engage one-way gear 122, and consequently the only portion of the low-speed drive linkage that is caused to rotate is pinion 126; by reducing friction, this makes it easier to manually haul a line around the winch when no mechanical advantage is required.
Further structural features of the winch mechanism are shown in FIG. 4. The base 24 is fixedly secured to gear housing 25 which is in turn fixedly secured to vertical sleeve 27. Gear housing 25 provides a convenient mounting for the various elements of the medium and low-speed drive linkages; sleeve 27 supports the drive shaft bearings (e.g. 92 and 94) and drum bearings (e.g. 96 and 98).
The winch drum body 93 is preferably made of cast nylon, sheathed by a protective metal shell 95 at those portions of the drum periphery most subject to wear from the lines to be hauled, and lined by a metal sleeve 99. Drum body 93 can be cast integrally with ring gear 23 (the outer surface of which is provided with threads 23a to prevent relative movement between the drum body and ring gear). Preferably, these threads, which are of low pitch, are roughened to reduce the chance of rotational movement of the gear with respect to the drum body and are oriented so that any torque which occurs when the winch is under load tends to bias the gear 23 into the drum body.
Proper choice of materials can greatly increase the strength and durability of the winch and can provide a significant reduction in weight for a given hauling capacity. For marine use, satisfactory results have been obtained by using a corrosion-resistant type 316 stainless steel for base 24, gear housing 25, and sleeve 27, and a harder high-strength type 17-4 RH" steel for drive shaft 26, cam-control rod 70, and the drive linkages. Yet stronger steels (e.g. type can be employed where operating requirements so dictate.
The preferred embodiment described above and shown in the figures provides a three-speed winch, but obviously the same principles of construction and operation can be applied to other winches with a greater or lesser number of speeds and of widely varying size and hauling capacity. Further obvious modifications permit the winch to be converted readily to powered operation.
Other embodiments will occur to those skilled in the art and are within the following claims.
What is claimed is:
l. A shaft engager for transmitting rotary motion of a drive shaft to any of a plurality of pinions comprising:
a plurality of independently rotatable pinions;
a rotatable drive shaft coaxial with said pinions and extending through them;
a plurality of drive cams, each associated with one of said pinions and mounted to said shaft for movement from a first extended position engaging said associated pinion and preventing relative rotation between said pinion and said shaft in at least one direction to a second retracted position not engaging said pinion and permitting relative rotation between said pinion and said shaft;
and, means for selecu'vely extending said drive cams to said first position and thereby causing said drive shaft to drive selected sets of said pinions, said sets each comprising at least one pinion.
2. The shaft engager of claim 1 wherein said means for selectively extending said drive cams comprise a cam-control rod coaxial with said drive shaft and movable relative thereto and having cam-control surfaces adapted to be positioned for cooperation with said drive cams.
3. The shaft engager of claim 2 wherein said cam-control rod is rotatable with respect to said drive shaft, the surface of said cam-control rod comprises sets of cam-control grooves, each such set adapted to be positioned to cooperate with an associated set of drive cams and to control the position assumed by the drive cams comprising said associated setin accordance with whether or not the angular orientation of said cam-control rod is selected to bring said set of grooves into angular registration with said set of cams, each set of grooves comprising at least one groove and each set of cams comprising at least one cam.
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