Cam Cleat Releasing Mechanism

Abstract

A releasing mechanism for cam cleats in which a fairlead over which a sheet (rope) can be optionally guided, is offset from the cleat such that when the sheet (rope) is guided by the fairlead and is tensioned, a releasing force component is created to free the sheet from the cleat.

Description

BACKGROUND OF THE INVENTION

This invention relates to cam cleats (often referred to as jamb cleats) of the type used primarily on small sailboats for gripping the main and jib sheets in such a manner that the held sheet may be instantly released whenever desired, as for example, to quickly spill the wind in the respective sail so as to avoid capsizing.

Cam cleats commonly comprise a pair of parallel-spaced swing-mounted cams with opposed jaws shaped to provide a flared forward entry therebetween for the sheet. The cams are spring loaded for yieldingly closing the jaws against stops. One axial end of the jaws, top or bottom, is open from the flared entry to the aft exit side and is tapered endwise of the cleats so that a tensioned sheet (rope), which is guided by a fairlead aligned with the flared entry, can be pulled from a position aft of the cleat and swung into the open end of the jaws such as to cause the cams to retract sufficiently against the action of their springs as to permit the sheet to move into the flared entry and between the jaws so as to be firmly gripped for preventing slackening of the sheet. The sheet is released from the cleat by pulling it axially of the cleats out through the open end of the jaws. However, difficulty is often experienced in so releasing the sheet when the sailor is in such a position in the sailooat that he must grip the sheet several feet away from the cleat. This problem is often compounded by the fact that the boat may be precariously heeled. A typical such cam cleat is shown in U.S. Pat. No. 2,627,834.

The principal object of the present invention is to obviate this difficulty of releasing the sheet from a cam cleat when the sheet need be manually gripped several feet from the cleat. Other objectives will appear from the detailed description of the invention.

SUMMARY OF THE INVENTION

In accordance with this invention a fulcrum for the sheet is provided aft of the cam cleat and displaced from the entry-exit line of the cleat in the direction corresponding to the open axial end of the jaws. This fulcrum may be pictured as one of the actue-angle vertices of a right triangle having its other acute-angle vertex located at the exit of the cleat and its right-angle vertex aligned with the entry-exit line of the cleat. To release the sheet it is looped over the fulcrum so as to become the hypotenuse of the afore-mentioned triangle. Then when the sheet is pulled from a position spaced from the fulcrum there is a pre-determined releasing force component established by the position of the fulcrum which is independent of the line from the sailor's gripping point on the sheet to the cleat. In other words, the portion of the sheet between the fulcrum and the cleat will always have the same pull line regardless of where the sailor exerts releasing tension on the sheet. The fulcrum is preferably formed as an attachment to the cam cleat assembly, particularly when the cam cleat is mounted on a swing arm, as is common for cleating jib sheets, and may be provided by a horn having a fairlead tip portion swing as the fulcrum. This horn may project inwardly from a closed loop which extends aft from the base of the cam cleat and serves to always keep the sheet convenient to the horn.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a cam cleat and related mechanism embodying the present invention;

FIG. 2 is a longitudinal vertical section taken along the line 2--2 of FIG. 1;

FIG. 3 is a rear elevational view taken as indicated by line 3--3 in FIG. 2; and

FIG. 4 is a fragmentary detail transverse vertical sectional view taken along line 4--4 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For purposes of example the invention has been illustrated applied to a cam cleat assembly 10 which is mounted on a stepped bracket arm 12 swivel-mounted on a slide carrier 14 together with a forward fairlead 16. The carrier travels on a track 15 and has a set screw 20 arranged to lodge into selected hole of a row of holes 21 along the track. Independent swivel movement is provided for the bracket arm 12 and the fairlead 16 by a bolt 18 passing through a base plate 22 for the fairlead, a washer 23, the arm 12, and the carrier 14. The step in the bracket arm is such as to generally align the eye of the fairlead 16 with the gap between the cam members 24-25 of the cleat assembly 10. No claim is laid to the above-described parts and mounting arrangement or to the specific construction of the cam cleat illustrated. They are only shown to make clear the operation of sheet releasing structure and action provided in accordance with the present invention.

As is conventional, the cam members 24-25 are in the form of a shell pivoted and held by a machine screw 26 on a base plate 28 integral with the bracket arm 12. Within the shell of each cam and surrounding the shank of the respective screw 26 is a coil spring 30 having one end thereof bent and secured in a hole in the head of the shell and its other end bearing against a stop pin 32 projecting into the shell from the base plate 28. The bias of the springs 30 is such as to urge the cams to rotate oppositely in a manner bringing the back walls 34 of the cams into transverse alignment bearing against the stop pins 32. Swinging of the cams in opposition to the springs 30 to open their opposed jaws 25'-26' is limited by engagement of the stop pins with the front walls of the cams.

The opposed jaws 25'-26' are serrated and have cam surfaces which are curved in the plane of the base plate to provide a flared entry facing the forward fairlead 16. From their base plate end the jaws are tapered outwardly slightly axially of the cams to an open axial end. This taper facilitates the entrance of a sheet into operative jamming position between the jaws. As is conventional, a U-shaped plate 36 may be provided which is held by the screws 26 and bridges the open axial end of the cams to provide a center retaining eye 36' for the sheet when it is released from the paws of the cams. This eye keeps the released sheet close to the entrance between the cams.

In accordance with the present invention a rigid loop member 40 is provided as an extension of the base plate 28 or may be secured as a separate component as by the screws 26. This loop member is shaped to have its arms extend rearwardly and also bend upwardly in the same general direction as the open axial ends of the cams 25-26 so as to locate the central upwardly arched portion of the member well above the level of the cams. Projecting from one of the side arms of the loop member to a tip slightly beyond the lateral center thereof is a horn 42 formed with a fairlead tip portion 42' which may be downwardly curved somewhat to conveniently seat a sheet. It is important to note that this fairlead 42' is purposely offset from the normal in-feed direction of a sheet as defined by the forward fairlead 16 and the gap between the cam jaws 25'-26'. The offset is such that when a sheet is passed aft from the cam cleat over the fairlead 42', an adequate releasing force component is induced on the portion of the sheet between the cam cleat and the horn 42 as to pull the sheet upwardly free of the cam jaws into the retaining eye 36' regardless of the pull line on the sheet aft of the horn. The loop member serves not only to position the horn but also assists in keeping the sheet convenient to the releasing fairlead 42' so that the sheet can be more readily looped over the fairlead particularly when a guide release of the sheet from the cam cleat is required. However, it is not essential for such release that the sheet occupy the fairlead portion 42' of the horn it being only necessary that the sheet be passed over some portion of the horn.

From the foregoing description it will be apparent that when the present invention is in operative position on a sailboat, the sheet is threaded from the respective sail through the forward fairlead 16, the retaining eye 36' and the loop member 40. When it is desired to set the sheet it is pulled downwardly from a point aft of the loop member and below the level of the cam cleat to force the sheet from the retaining eye 36' to a gripped position between the cam jaws 25'-26'. Then, when release from the cam cleat is required, the sailor need only loop the sheet over the fairlead portion 42' or some other portion of the horn 42, and pull on the sheet from any location aft of the horn in which the sailor happens to be (see FIG. 2).

For purposes of example the invention has been shown applied to a cam cleat which was mounted on a swing arm and for which the release pull direction is upwardly. It is to be understood that the invention also can be applied to cam cleats which are fixed and/or which release by a downward pull or in some other direction. Also, it is not essential for a practice of the basic concept of the invention that the forward fairlead 16 or retaining eye 36' be provided since these are not concerned with release of the sheet from the cam cleat. Furthermore, if the cam cleat is kept in a fixed location the releasing fairlead 42' may have a mounting separate from that of the cam cleat. In this regard, although the loop member 42 is advantageous in keeping the sheet convenient to the releasing fairlead 42', the practice of the present invention is not confined to use of a retaining loop in conjunction with the releasing fairlead.

Also important is the fact that although the invention has been illustrated applied to a cam cleat of the type having two opposed swiging cam members, it is to be understood that the term "cam cleat" when used in the accompanying claims is intended to encompass cam cleats or jamb cleats in which there is only one movable gripping jaw.

Claims

I claim:

1. In combination,

cam cleat means having a sheet gripping station between forward and aft ends and having a lateral sheet releasing direction,

a sheet confining loop extending rearwardly of said cam cleat and offset generally in the sheet releasing direction,

and an optionally usable sheet guiding fulcrum mounted in the loop whereby a sheet releasing force component is exerted in said releasing direction when a sheet gripped by said cam cleat means is tensioned while guided by said fulcrum.

2. The combination of claim 1 in which said fulcrum is provided near the tip of a horn projecting inwardly from the loop.

3. In combination, a cam cleat means having a sheet gripping station and having an infeed-outfeed axis defined by opposite infeed and outfeed directions and a sheet introducing-releasing axis defined by opposite introducing and releasing directions, said axes intersecting at cross-angles to one another at said station and together defining a working plane, said cam cleat means permitting a sheet to only feed in the infeed direction while occupying said station and permitting said sheet to be released from said station in said releasing direction for freedom to then feed in said outfeed direction, and releasing fairlead means spaced from said infeed-outfeed axis and providing a sheet guiding fulcrum in said working plane, said fulcrum being spaced from said sheet-gripping location in a diagonal direction between said infeed and releasing directions and having an unobstructed side open at right angles to said working plane, whereby a sheet gripped by said cam cleat means may be released as a consequence of being manually looped over said fulcrum and tensioned from a pulling location situated beyond the fulcrum in the outfeed direction even if the pulling location is aligned with the infeed-outfeed axis.

4. The combination of claim 3 in which said releasing fairlead means comprises a sheet guiding loop projecting generally in said diagonal direction from said cleat means and having an inwardly projecting horn with said fulcrum adjoining its tip.