US2165756A - Ratchet mechanism for winches - Google Patents

Description

July 11, 1939. c c, M N 2,155,756

' 4 RATCHET MECHANISM FOR WINCHES Filed Aug. 20, 1938 N V IN VENTOR. I J 1 B 0mm 55 6. MART/A A ATTORNEYS.

Patented July 11, 1939 UNITED STATES PATENT OFFICE Charles C. Martin, Cleveland Heights, Ohio, as-

signor to David Round & Son, Garfield Heights,

Ohio

Application August 20, 1938, Serial No. 225,945

6 Claims.

This invention, as indicated, relates to a ratchet mechanism for winches. More particularly, it comprises a pawl and ratchet mechanism which in one position of the pawl permits rotation of the drum to take up on the cable and hold the same against release, and in another position of the pawl provides for free rotation of the drum of the winch with the pawl positively held free of engagement with the ratchet teeth.

7 The invention includes features of construction providing a simplified and highly dependable mechanism of sturdy construction and of long service life without attention.

In certain types of apparatus, particularly in connection with screw-geared winches it is desirable to provide a ratchet mechanism permitting free take-up of the cable on the drum during one period of operation and to free such drum of the ratchet mechanism during another stage of the operation. For each of the stages of operation referred to it is desirable to have the pawl positively held in operative position, or in inoperative position, so that no accidental movement of the pawl from one position'to the other will take place. This is of particular importance where the winches areused on shipboard or on small water craft inasmuchas the accidental movement of the pawl from one position to the other may cause serious consequences. The mechanism herein set forth is designed to supply a pawl of simplified construction and of dependable operative characteristics so that a winch provided with such mechanism may be operated with a maximum of security.

The principal object of the present invention is to provide a ratchet mechanism for winches of simplified construction, but havingoperative elements of sturdy and dependable character which will function reliably under conditions of heavy service requirements.

Another object of the invention is to provide a pawl and ratchet mechanism for winches wherein the pawl may be positively moved to op- .erative position, and may also be positively held in retracted position when desired.

A further object of the invention is to provide a pawl and ratchet mechanism for winches wherein the pawl may be positioned adjacent the lower portion of the winch at a point free of in-- terference with other mechanism, and yet may be readily accessible for movement to operative or inoperative position when required.

A further object of the invention is to provide a pawl and ratchet mechanism for winches wherein the pawl is positioned adjacent the lower portion of the ratchet, and is provided with means for cooperating with the base plate of the winch to hold such pawl resiliently in enagement with the ratchet teeth in one position of adjustment or to positively hold such pawl out of engagement with the ratchet teeth in another position of adjustment.

Other and further objects of the invention will appear in the course of the following description.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims, the annexed drawing and the following description setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but several of various forms in which the principle of the invention may be used.

In said annexed drawing:

Fig. 1 is a fragmentary end elevation of a winch with a pawl and ratchet mechanism in operative engagement, as shown in dotted lines;

Fig. 2 is a fragmentaryside elevation of the end portion of a winch illustrating the pawl and ratchet mechanism, as shown in Fig. 1;

Fig. 3 is an enlarged fragmentary side elevation of the pawl and ratchet mechanism showing the base plate in section as seen along the line 3-3, shown in Fig. 2, looking in the direction of the arrows;

Fig. 4 is a View similar to Fig. 3 showing the pawl positively held in a position disengaged from the ratchet; and

Fig. 5 is an enlarged detailed view taken along the line 55, shown in Fig. 3, looking in the direction of the arrows.

As is clearly shown in Figs. 1 and 2, the winch comprises a base plate I and an end plate 2 securely mounted thereon, said end plate being provided centrally with an aperture 3 forming a bearing for the stub shaft 4 forming a part of the drum assembly of the winch. The drum 5 has an end flange 6, and outwardly thereof is provided with a ratchet member 1 slightly spaced from the end flange 6, with its outer face in contact with an anti-friction bearing within a stationary collar 8 secured to the inner face of the end plate 2 by welding or other suitable means and mounted concentrically with the stub shaft 4 of the drum.

At a point adjacent one side of the end plate and approximately in the horizontal plane of the lower margin of the ratchet wheel a boss II is secured by welding or other suitable means to the inner face of the end plate, the boss and plate being perforated and screw-threaded to receive a pivot bolt |2 having an enlarged bearing portion l3 over which an aperture M in the body of the pawl l5 may be engaged. The pivot bolt has an integral screw-threaded stem section |6 adapted to be engaged by a nut I'l bearing against the outer face of the end plate 2.

The body portion of the pawl is preferably in the form of a fiat plate having the pivot opening |4 approximately centrally thereof, and having a ratchet engaging terminal 2| at one end ther e-,v

of and a handle 22 at the opposite end thereof. In the form shown in Figs. 3 and 4, it will be noted that as seen from the side the pawl is in the form of a shallow inverted V with the pivot centrally thereof and the handle section and ratchet terminal section meeting at an angle.

The terminal 2| is suitably shaped to provide an upwardly inclined surface 23 to conform sub: stantially to the adjacent beveled face 24 of one of the ratchet teeth 25 which preferably have short flattened areas 26 adjacent the end faces 21 of the ratchet teeth. The end surface'29 of the pawl preferably conforms to the end face of' the ratchet teeth, the radial angle of such surfaces in relation to the pivot of the pawl preferably being such that a slight movement of the drum occurs when the pawl is moved to releasing position. In other words, the ratchet teeth'are in effect slightly undercut to provide continuous latching engagement until the' pawl is moved manually to releasing position. This locking action is wholly independent'of the spring-toggle mechanism presently to be described.

The handle 22 of the pawl projects beyond one side of the end plate 2 of the winch structure and is preferably shaped to be conveniently grasped by'the hand of the operator, as is clearly shown in Fig. 1 of the drawing.

In orderto positively hold the pawl'in either ratchet engaging or in ratchet releasing position;

a spring toggle mechanism "is provided, such structure comprising a pivot plate 3| preferably formed as a'projection'on 'a head 32 having an integral threaded'stem 33 adaptedto be engaged. in a threaded recess 34 formed in the underside of the body of the pawl'somewhat in advance of the central vertical-plane of the pivot opening I l of the pawl toward the ratchet engaging side thereof. The other parts of the spring toggle mechanism comprise a pivoted "togglemember preferably in the fo'rm'of ash'ortcylindrical bar slot 36 and a pivot pin 39 is engaged through said alined apertures. The ends of the pivoted members are rounded to permit free pivotal move ment of the parts when'the pawl is'shifted as will' be presently explained;

As has been indicated, the upper end of the spring 38 is engaged within the spring housing 31 in the toggle bar 35. The lower end of the spring, as is'shown more particularly in Figs. 3, 4' and 5, is received within a shallow recess 4| formed in the base plate I of the winch' at a point offset slightly from the vertical plane through the pivot opening I4 of the'pawl, in a direction toward the handle end of the pawl.

The spring 38 is preferably made of slightly spaced turns of wire of suitable gauge and of a normally extended length greater than the distance between the bottom of the recess 4| in the base plate and the bottom of the recess 31, so that the spring will be constantly under compression when assembled in the spring-toggle mechanism. The spacing of the spring coils is such as to permit further compression of the spring as the pawl is moved from engaged to released position with the spring reaching maximum compression as the spring-toggle mechanism passes dead center.

By reason of the construction just explained the spring acts/against the pawl first on one side of the pivot of the pawl, and then, when the pawl is manually moved, to its opposite position, on the opposite side of the pivot of the pawl. While the pawl has a wide range of movement from engaged to released position, it will be noted that the spring-toggle elements have relatively small range of movement. The coil spring 38 itself forms an active structural part of the springtoggle mechanism obviating the necessity of a pivot pin at the'lower end of the toggle linkage, and affording a most simple and convenient means of assembly of the parts. It provides a minimum of structural elements and a base plate entirely free of pivot ears or bosses, which have a 'tendency to accumulate foreign matter in the restricted space and thus require constant examination to insure the dependable operation of the apparatus.

It will be noted that the ratchet wheel provides the upper limit of motion for the pawl and that the spring-toggle provides for resilient engagement of the pawl terminal 2| with ratchet teeth successively as the winch is turned in cable winding direction. When the pawl in retracted or releasing position, the base plate I, as shown in Fig. 4, provides the stop at the lower limit of motion, the lower edge of the pawl terminal contacting the base plate.

'While the ratchet terminal end of the pawl could be made heavy enough to move to retracted position when released, where the device is used on shipboard, it is desirable to positively hold the pawl in retracted as well as in engaged position, and both of these functions are'served by the double acting spring-toggle structure herein provided.

Other modes of applying the principle of my invention may be employed instead of those explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claimsor the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:-

1. An apparatus of the character described having in combination, a winch drum carrying a ratchet wheel at one end, a supporting frame for said winch having a base plate and having an end plate in spaced relation to said ratchet wheel, a stub shaft projecting axially from said winch drum and received in a suitable aperture in said end plate, a pawl pivotallymounted on said end plate adjacent the forward lower corner thereof and. having one end portion projecting beyond said end plate to provide a handle and the opposite end portion projecting beneath the ratchet wheel, and resilient means mounted on said base plate for selectively holding said pawl in engagement with said ratchet wheel and in retracted position.

2. An apparatus of the character described having in combination, a winch drum carrying a ratchet wheel at one end, a supporting frame for said Winch having a base plate and having an end plate in spaced relation to said ratchet wheel, a stub shaft projecting axially from said winch drum and received in a suitable aperture in said end plate, a pawl pivotally mounted on said end plate adjacent the forward lower corner thereof and having one end portion projecting beyond said end plate to provide a handle and the opposite end portion projecting beneath the ratchet wheel, and a spring toggle unit positioned intermediate said base plate and pawl structure for selectively holding said pawl in engagement with said ratchet Wheel and in retracted position.

3. An apparatus of the character described having in combination, a ratchet wheel associated with a winch mechanism, a Supporting frame having a base plate and end plate for said mechanism, an elongated plate having one end pivoted at a central point to said end plate and having one end projecting beneath said ratchet wheel with the opposite end projecting beyond said end plate to provide an operative handle, and a spring toggle mechanism interposed between the elongated plate and the base plate to selectively hold said projecting end of the plate in engagenism, an elongated plate having one end pivoted at a central point to said end plate and having one end projecting beneath said ratchet wheel with the opposite end projecting beyond said end plate to provide an operative handle, a spring receiving sleeve hingedly secured to the under side of said lever adjacent the central pivot of the lever, and a coil spring having one end engaged within said sleeve and its opposite end engaged within a recess provided in said base plate substantially in alinement with the pivot of said elongated plate, said spring and hinged sleeve forming a spring toggle for selectively holding the active end of said lever in engagement with said ratchet wheel or in retracted position.

5. An apparatus of the character described having in combination, a supporting frame in-. cluding a base plate and an end plate, a ratchet wheel associated with a winch drum positioned in spaced relation to said end plate, a stub shaft on said winch drum for pivotally supporting said winch unit in said end plate, an elongated plate providing a handle at one end and a pawl at the opposite end for active engagement with said ratchet wheel, means centrally of said plate for pivotally supporting the same for movement into and out of engagement with said ratchet wheel, and a spring toggle mechanism interposed between said plate and said frame for actuating said plate, said spring toggle mechanism comprising a hinged member providing a housing for one end of a coil spring and a coil spring engaged in said housing with its free end received in a recess in one of the abutting members.

6. An apparatus of the character described having in combination, a supporting frame including a base plate and an end plate, a ratchet wheel associated with a winch drum positioned in spaced relation to said end plate, a stub shaft on said winch drum for pivotally supporting said winchunit in said end plate, an anti-friction bearing interposed between said end plate and said ratchet wheel concentric with said stub shaft, an elongated plate providing a handle at one end and a pawl at the opposite end for active engagement with said ratchet wheel, means centrally of said plate for pivotally supporting the same for movement into and out of engagement with said ratchet wheel, and a spring toggle mechanism interposed between said plate and said frame for actuating said plate, said spring toggle mechanism comprising a hinged member providing a housing for one end of a coil spring and a coil spring engaged in said housing with its free end received in a recess in one of the abutting members, the hinged portion of said spring toggle mechanism being positioned beneath the pivot of said elongated plate and adapted to be moved past dead center to either side thereof to selectively hold said pawl terminal of said plate in engagement with said ratchet wheel or in retracted position.

CHARLES C. MARTIN.

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