Winch is typically designed for heavy duty applications and are constructed of expensively machined parts to withstand the forces they are expected to encounter. Whereas there are many potential uses for winches by consumers (for personal use as differentiated from commercial use), winches heretofore available have been either of the expensive variety (with expensively produced machined parts) and thus prohibitively costly for most consumer uses, or they were so limited in their capability as to be inadequate for many consumer winching needs.
The present invention provides a unique design for a winch that enables the use of heavy duty steel where needed to withstand substantial loading of the winch, in combination with less expensive molded plastic, powder metal and stamped parts and the like, where high strength of the material is not as important a factor. A particular benefit of the invention is the achievement of common parts in a number of the sub assemblies of the winch. This commonality of parts dramatically reduces the production costs.
The operation of the winch will now be reviewed. The motor 16 is capable of rotating shaft 46 in either direction i.e. for winding and unwinding the wire rope 18 onto and off of drum 36 as desired. Shaft 46 is engaged with sun gear 52 which rotates the planet gears 60 of the first planetary carrier assembly 54. Gears 60 being also inter-engaged with gear teeth 62 of housing element 50 (which gear teeth 62 thus function as a ring gear) force turning rotation of the entire planetary carrier assembly. The purpose of the planetary carrier assembly is of course to reduce the rotation of the output 46 of the motor 16. Thus depending on the ratio of the number of gear teeth 62, to the number of gear teeth on sun gear 52, the sun gear 52 has to rotate a number of times in order for the planetary gear assembly to make one complete revolution. That reducion e.g. of five to one, is transferred by output shaft 72 of the carrier assembly to shaft 74 and then to sun gear 80. Sun gear 80 engages the planet gears of planetary carrier assembly 86 and with the same five to one ratio of reduction between gear teeth 62 in second housing section 78 and gear teeth 86, output shaft 88 turns at 1/5th the rotative rate of gear 80 and 1/25th of the rate of output shaft 46.
Output shaft 88 functions as the sun gear to the third planetary carrier assembly 90 and turns drive gear 92 at 1/5th its speed. Output shaft 92, being directly splined to drum 36, thus rotatably drives the drum 36 at 1/125ths the rotative speed of drive shaft 46 of the motor 16. The motor 16, being rotatably drivable in either direction, winds and unwinds the wire rope 18 from the drum 36 through the fairlead 100 of the base plate 22 (FIG. 2).
In an alternate embodiment, illustrated in FIGS. 5 and 6, means are provided to disconnect the second planetary gear assembly from the shaft 102 (corresponding to shaft 74 above) thus disconnecting the first and second planetary gear assemblies. Shaft 102 is allowed limited axial movement between a far left or retracted position (shown in dash lines) with the hexagon configuration of the shaft disconnected from sun gear 80, and a far right or engaged position (shown in solid lines) with the hexagon configuration of the shaft connected to sun gear 80. A spring 104 compressed between the first planetary carrier assembly and a retainer 106 on the shaft 102, urges the shaft 102 toward the interconnected position.
Mounted to the outside of housing element 78 is a cam activated disconnect mechanism 108. A cam follower 110 including three cam following fingers 112, is axially slidable but rotatably fixed relative to a cap 114. The thrust bearing 84 is carried by the follower 110 and remains in continuous engagement with the end of the shaft 102. The cap 114 surrounds the cam follower 110 and is axially fixed but free to rotate relative to the housing. Cap 114 has a cavity that allows axial movement within the cap. Provided in the housing 78 are cam surfaces or ramps 118 positioned in engagement with each of the cam following fingers 112, i.e., at interface points 116 in FIG. 5. The ramps 118 extend right to left. Forcing the fingers down the ramp surfaces 118 i.e. by turning the cap, forces rearward movement of the cam follower 110 in the cavity of the cap 114. Thus it will be appreciated that manually turning cap 114 clockwise (as viewed in FIGS. 5 and 6) causes rotative movement of the fingers 112 relative to ramps 118 to force the fingers to the left within the cavity of the cap. Counterclockwise movement of the cap allows the cam follower to move to the right. This movement is urged by spring 104, (acting against shaft 102, which abuts thrust bearing 84 carried by the cam follower).
The inventive concept of this invention is believed to reside in several areas. Splitting the planetary carrier assemblies so as to place them on both sides of the drum is believed to have a very significant benefit. Whereas molding long splines in a housing section (e.g. extensions of spline 62) is impractical, the present invention avoids the problem by generating the interconnection of shaft 74 (102) to allow the planetary carriers to be located at both sides of the drum. The planetary carrier assemblies and other sub assembly parts of the winch have common parts that can be mass produced and fit into the various assemblies at substantially reduced manufacturing cost. Similarily, housing elements 50 and 78 are essentially identical except only for the access holes for drive shaft 46 and mechanism 108. The above spliting of planetary carrier assemblies to provide for molded housing elements, e.g., of plastic nylon, is made feasible by reason of the direct support for the drum 36 through the mounting brackets 24, 28 and base 22. The invention is however, considered to be broader than the specific examples herein described, and accordingly the scope of the invention is specifically defined in the claims appended hereto.
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