US3642253A

US3642253A - Sealed silent winch

Info

Publication number: US3642253A
Application number: US842428A
Authority: US
Inventors: William C Baldwin; Theodore N Meyer
Original assignee: Plasmachem Inc
Current assignee: Plasmachem Inc
Priority date: 1969-06-23
Filing date: 1969-06-23
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15

Abstract

A hand-operated winch designed for marine craft and in particular for use as a sailboat sheet winch is disclosed. All braking and bearing elements are sealed and not exposed to the elements. It includes silent one way clutches as opposed to conventional pawl escapements for braking. Several different winch diameters may be produced using a common working mechanism since the drum is separable from the working mechanism. Dual thrust rings allow axial loads to be sustained.

Description

United States Patent Baldwin et al.

[ 1 Feb. 15, 1972 [54] SEALED SILENT WINCH 2,836,085 5/1958 Snyder ..254/187 UX [721 Inventors: William 0. Baldwin, Anaheim; Theodore 5:32; "321x33 y westminister both of Calif. [73] Assignee: Plasmachem lnc., Newport Beach, Calif. FOREIGN PATENTS 0R APPLICATIONS 182,226 7/1922 Great Britain ..1 14/1 1 i [22] 1969 527,743 10/1940 Great Britain.. .2s4/150 [2]] Appl. No.2 842,428 731,014 3/1966 Canada ..254/150 Primary Examiner-Harvey C. Homsby {g 254/186 Assistant ExaminerMerle F. Maffei 0 l e I e e e n n e n n n I e e n n e e n e e n e n e e e e n n u u a v v e e e e e n e e J h E. w 153 Field of Search ..254/150, 187, I80 HC, 184; agner ll4/lll;2l4/l32 57 ABSTRACT 5 R f n Cited A hand-operated winch designed for marine craft and in particular for use as a sailboat sheet winch is disclosed. All brak- UNITED STATES PATENTS ing and bearing elements are sealed and not exposed to the elements. It includes silent one way clutches as opposed to James conventional p escapements for Several different 755953 3/1904 f winch diameters may be produced using a common working 1,570,061 [/1926 Henr'cksm mechanism since the drum is separable from the working 8 i mechanism. Dual thrust rings allow axial loads to be sustained. o 2,501,096 3/1950 Robins et al. ..254/187 X 1 Claim 8 Drawing Figures SEALED SILENT WINCH BACKGROUND OF THE INVENTION Winches for handling lines on marine craft in particular sailing boats have traditionally employed a mounting base, some type of escapement or one-way brake and an outer drum with a reduced diameter waist for holding a number of turns of working lines. Hand winches often employ a socket at the top for mounting a crank handle for manual operation.

Because these winches are mounted on the weather deck of low-freeboard vessels and exposed to extremely arduous conditions the working mechanisms are subject to submersion and damage from corrosion. The internal mechanisms are therefore designed to be as simple and corrosion resistant as possible. The traditional spring-loaded pawl and star gear has been used for many years as the brake mechanism of the hand winch. Despite the simplicity of the traditional design existing winches require necessary servicing or lubrication because the locking mechanism is exposed to water leaking either from the top crank opening in certain cases or under the drum. In some cases the base of the winch i's cup-shaped and it actually traps and holds seas.

One further limitation on existing winches relates to their internal design. Since winches are designed to accept tangential loading, little, if any consideration has been given to axial loading. In certain winches only a light assembly screw sustains any axial loading.

Another and extremely important deficiency in prior art winches is the fact that the conventional pawl-locking mechanisms often constitute the noisiest piece of working gear on a sailboat. Where the boat is used for racing, the characteristic chatter of a pawl winch is the signal to competitors that the boat is undergoing a manuever. Often the matter of a few seconds in making a manuever can make the difference between win and loss in a race and the signaling to all within ear shot of a manuever by the noise of the winch is totally unnecessary. This is particularly true during overnight racing where the contestants cannot see sail movement.

A further slightly less glamorous consideration is that in prolonged sailing voyages where manuevers from sail handling must occur at all hours, the operation of conventional winches is disturbing to sleeping crewmen.

BRIEF DESCRIPTION OF THE INVENTION In view of the foregoing deficiencies in the prior art, there is an object of our invention to produce a completely sealed mechanism winch which is not subject to the damage by exposure to normal-operating marine conditions. The second object of our invention is to provide a winch which is silent. A further object of our invention is to provide a winch which includes no areas which will trap water internally.

Still another feature of this invention is a novel dual-thrust ring assembly which absorbs axial loading on the winch.

One further feature resides in a highstrength low-weight drum which is interchangeable to provide variable size winches using a common working mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features of this invention may be better understood from the following detailed description and by reference to the drawing in which:

FIG. 1 is a perspective view of a hand winch of this invention;

FIG. 2 is a partial vertical section through the body of the winch of FIG. 1 showing the working mechanism;

FIGS. 3, 4 and 5 are sectional views of three different size winches using the same working mechanisms;

FIG. 5a is a fragmentary section of the assembly of FIG. 5 taken along lines 5a5a of FIG. 5;

FIG. 6 is a perspective view of a sprag clutch constituting the braking mechanism of this invention; and

FIG. 7 is an enlarged fragmentary diametrical sectional view of the sprag clutch of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION Now referring to FIG. 1, a hand winch 10 in accordance with this invention has the general exterior appearance of prior art winches including a drum 11 having an enlarged base 12 and a reduced waist portion 13 which may be a smooth, slightly tapered surface, or roughened for increased friction with lines to be handled. At the upper end of the drum 11 is a cap 14 of slightly smaller dimension than the base portion 1' and having a central socket 16 for receiving a handle 15. The cap 14 and drum 11 are preferably separable members in accordance with this invention.

The winch 10 of FIG. 1 includes an internal one way clutch or braking device which allows a line to be drawn up by operation of the handle in one direction, for example, clockwise as shown in the drawing and prevents and resists unwinding in the counterclockwise direction. A typical application of a winch of this type is in handling the sheet lines of a sailboat. In certain cases the handle 15 may include a double handle to allow two persons to work together in drawing up a line under heavier load conditions.

As shown in FIG. 1, the winch has all the appearances of conventional prior art winches designed to take lines and circumferentially around the waist portion 13 with tangential loading of the drum in the direction of the dashed line a in FIG. 1. We have found, however, that a winch having a substantial lip on the cap 14 is a natural place for attaching lines for lifting. For example, in the case of a submerged or partly submerged boat where some lines must be attached to raise the boat. In such case the winch is subject to loads in a general axial direction typified by the dashed arrow 6 of FIG. 1. The winch in accordance with this invention is designed to accept all required loads in either of the above two directions or with components in either direction.

For an understanding of the mode of operation and internal workings of the winch of FIG.. 1, now refer to FIG. 2 showing the winch partially in section. In addition to the drum 11 and cap 14 of FIG. 1 a concealed base 20 may be seen. The base includes a number of screw holes 21, one of which is shown designed to receive flathead screws for mounting the winch on the deck. Since the winch is also designed to accept axial loads, the mounting plate 20 may include a matching backing plate designed for under deck mounting and in such cases the flathead screws intended for holes 21 would be replaced by flathead machine bolts. In any event the mounting plate 20 includes a riser portion 22 with internal threads 23 mating with a central shaft 24 constituting the heart of the drive mechanism of the winch.

The shaft 24 includes an integral braking surface 25 having a diameter of approximately double of the body diameter of the shaft 24. Above the braking surface of race 25 is a longer medium diameter portion 26 with a thrust ring groove 30 and a step 31 joining a reduced diameter end portion 32. This end portion 32 includes a second thrust ring groove 34 and end step 35. I

A first sprag-type clutch 40 encircles the braking surface 25 with the internal surface of the sprags of clutch 40 hearing on the surface 25. The outer ends of each sprag member bears on an encircling sleeve 43. The center portion 26 ofshaft 24 constitutes the support for the inner race of a pair of

ball bearing assemblies

41 and 42 which have their outer races positioned on steps of sleeve 43. The lower ball bearing assembly 41 is positioned between the upper edge of the surface 25 and an internal shoulder 44 of sleeve 43. Bearing assembly 42 is restrained from axial movement by the shoulder 44 and a thrust ring 45 in groove 30.

A second one way clutch or braking device 60 between cap 14 and the drum 11 allows the handle 15 (of FIG. 1) to be turned in a counterclockwise direction free of the drum to obtain the equivalent of ratcheting of the handle. This one way clutch 60 also allows the drum to free wheel with the handle held by the user.

The second thrust ring 46 in groove 34 retains a belleville washer 51 bearing against a lip of a two-part sleeve 50. The

sleeve includes an inner bronze bearing which is shown of generally Lushaped in the drawing and an outer hardened steel surface which constitutes the internal braking surface for the sprag clutch 60. The sleeve 43 provides the outer braking surface for the sprag clutch 60.

The belleville-type washer 51 and bearing against sleeve 50 applies axial loading of the cap assembly against the step 31 of the central shaft 24. This axial loading is just sufficient to hold the cap (and handle, if installed) when the drum is freewheeling. Any operating force applied by the operator to the handle overcomes the frictional load produced by the belleville washer 51 allowing the handle to drive the drum 12 and cap 14 in a normal manner. This feature eliminates any freewheeling of the cap and handle which can be dangerous to nearby personnel.

The sleeve 50 at its upper end is internally threaded 61 to receive a capnut 66 having internal recess 62 for receiving a handle. The capnut 66 is sealed by an O-ring seal 63 to the cap 14. The cap l4 is sealed to the drum 11 by a fiat washershaped seal 64 which may be of neoprene material. The base 20 and drum 11 are sealed against the entrance of moisture into the working mechanism by a similar seal 65.

The winch as shown is designed to rotate freely in one direction; for example, clockwise on the

ball bearings

41 and 42 while restrained from rotating in the opposite direction by the sprag clutch 40. The sleeve 43 which is shown as a separate part from the drum 11 is secured thereto so that in operation the drum 11 and sleeve 43 move as a single part. In this manner the drum moves freely in one direction and is securely locked by the sprag clutch 40 from movement in the opposite direction. The entire mechanism is contained within the

seals

64 and 65.

In installation the base 20 is first installed using screws through holes 21 and the capnut 66 is removed exposing a screwdriver slot (unshown) in the end 35 of the central shaft 24. Using the screwdriver slot, the central shaft 24 is threaded into the base 20 to mount the winch and then the cap plug 66 is reinserted into the cap 14. The winch is then installed with all seals in place and ready for operation.

In the case of immersion of the winch, the entrance of any water into the working mechanism is prevented by the

seals

64 and 65. Where the passage is between the cap 14 and drum 11 or between the drum 11 and base 20 the surfaces are slightly tapered outward and downward to permit any water entering the winch to run out freely without being retained or reaching the working mechanism.

It should be noted that in FIG. 2 that drum 11 is separate from the sleeve 43 but the two operate as a single member when the winch is in use. The drum 11 and sleeve 43 during the manufacturing process may be permanently joined together as by welding or secured by a number of longitudinal splines not shown in the drawing. In either case the winch in its final assembly form is made up in two separate parts. The reason for the separate construction of these two parts is more clearly apparent in FIGS. 3, 4 and which also illustrate another feature of this invention.

Referring now to FIGS. 3, 4 and 5. FIG. 3 in which the central shaft bearing and sprag clutches are removed and the sleeve 143 corresponding to sleeve 43 of FIG. 2 may be seen including the same stepped internal ring surfaces designed to receive a sprag clutch at each end, the ball bearings on the next level and the latter being retained from axial movement by a central annular shoulder. Encircling the sleeve 143 is a second sleeve 144 which may be press fit or otherwise secured to ring 143. In this case the drum is made up of a pair of flared

bell portions

120 and 121 joining the center of the narrow waist portion of the drum. These flared drum portions are preferably manufactured by rolling or spinning from stainless steel tubing. By comparison with FIG. 1, it can be seen that there is significantly less metal in the drum assembly of FIG. 3 compared with that of FIG. 2. This can produce a significantly lighter weight winch. Also the two drum parts can be produced by roll-forming, spinning or other manufacturing process which can be less expensive than forging or machining in the case of the structure of FIG. 2. In the region where the radial forces are applied to the winch the drum parts and 121 are backed by solid material of

sleeves

143 and 144 providing the same degree of strength as the drum assembly of FIG. 1.

with the basic diameter of the winch increased from D] to D2 I as shown in FIG. 4. Of course a larger pair of drum halves are required. FIG. 5 shows even a larger winch produced with the same mechanism and a larger sleeve 343 encircling the central sleeve 143 to produce a winch of diameter D3. In this case the sleeve 343 should have lightening holes as shown or spokes as shown in FIG. 5a.

A prime feature of the invention resides in the silent, but ef fective braking system employing the sprag clutches. A design of such clutches is more clearly illustrated in FIG. 6 as including a number of individual sprags 40b loosely restrained in one or more slotted rings 40a. The sprags include an outer and inner working surface and are loosely mounted in the ring 40a for slight pivotal movement. The sprags are pitched slightly with respect to the diameter of the ring 40a and the outer surfaces as illustrated more clearly in FIG. 7 are curved. With the eccentric mounting in the curved surfaces the sprags tend to allow relative movement between an outer andan inner.enclosed race or braking surface. Thus the sprags have a preferential direction of movement as is clearly indicated in FIG. 7. As shown there, the sprags 40b allow relative movement of the outer race with respect to the inner one in the direction of the arrow. Whenever relative movement in the opposite direction is attempted the sprags tend to straighten to a radial alignment position and effectively lock the two races from movement. In a typical l8 sprag clutch, a braking force in the order of 400 ft.-lbs. is easily developed. With such clutches a winch having a diameter of three inches can provide a tangential braking force of 2,500 to 3,000 lbs. and is virtually free running in the opposite direction.

From the foregoing it may be seen that we have produced and improved a winch in which the working mechanism is entirely sealed hereby increasing the life and minimizing, or eliminating maintenance. The winch also employs no pawl mechanisms; instead silent sprag-type clutches which constitute effective brakes in one direction. The central shaft of the winch includes two thrust rings designed to transfer axial loads on the drum and cap to the shaft whereby the winch is capable of sustaining axial loads at least as great as the normal tangential braking force. The winch includes a sleeve member containing the entire working apparatus whereby the final diameter of the winch may be changed merely by adding additional encircling sleeves and an outer drum. The outer drum is shown as a form tubular member in order to minimize the weight while maintaining the required strength.

The above described embodiments of this invention are merely descriptive of its principles and are not to be considered limiting. The scope of this invention instead shall be determined from the scope of the following claims including their equivalents.

We claim: 1. A deck winch comprising: a base for mounting on a deck; an upstanding shaft mounted on said base; a drum including an outer surface for holding working lines and an inner coaxial surface; bearing means engaging said shaft and inner coaxial surface of said drum for mounting said drum for rotation about said shaft; a first sprag clutch encircling said shaft and in one-way braking engagement with said shaft in drum;

a separate cap for said winch overlying said drum and including a closed end socket recess for insertion of a handle to drive said winch;

said cap including a tubular sleeve portion encircling said upstanding shaft and in rotational engagement therewith;

a second sprag clutch engaging the outer surface of said tubular sleeve portion of said cap and an inner surface of said drum whereby said cap and drum are engaged for one-way driving of said drum by said cap;

said first and second sprag clutches oriented for braking in opposite directions whereby said cap applies driving force

Claims

1. A deck winch comprising: a base for mounting on a deck; an upstanding shaft mounted on said base; a drum including an outer surface for holding working lines and an inner coaxial surface; bearing means engaging said shaft and inner coaxial surface of said drum for mounting said drum for rotation about said shaft; a first sprag clutch encircling said shaft and in one-way braking engagement with said shaft in drum; a separate cap for said winch overlying said drum and including a closed end socket recess for insertion of a handle to drive said winch; said cap including a tubular sleeve portion encircling said upstanding shaft and in rotational engagement therewith; a second sprag clutch engaging the outer surface of said tubular sleeve portion of said cap and an inner surface of said drum whereby said cap and drum are engaged for one-way driving of said drum by said cap; said first and second sprag clutches oriented for braking in opposite directions whereby said cap applies driving force from said cap to said drum when said cap is driven one direction and said drum is braked from rotation in the opposite direction wherein said upstanding shaft includes two step portions and a retaining groove in each step portion; a thrust bearing ring secured to each the first and second step portion of said upstanding shaft; one of said thrust bearings engaging said tubular sleeve portion of said cap; and the second of said thrust bearings engaging said drum.