Abstract:
A sailboat winch handle system has a locking plate that is mounted in a fixed configuration to the bottom of the winch handle plug and prevents the accidental removal of the winch handle from the socket of a winch. Normally, only downward and rotational forces are applied to the winch handle. The locking plate engages an interior surface of the winch socket when an upward force is excerpted upon the winch handle preventing the winch handle form accidentally being dislodged from the winch socket.

Description:
FIELD OF THE INVENTION 
     This invention relates to winch handles or hand cranks which are used to rotate a winch. 
     BACKGROUND OF THE INVENTION 
     Sailboats utilize sails to drive propel boats through the water. Ropes or lines are used to control the shape and position of the sails. The sails are typically triangular and configured with an upper comer (head), forward comer (tack) and rear corner (clue). The shape and position of the sails are controlled by lines which are made of rope and/or wire. The lines connected to the head of the sails are called halyards. The lines connected to the clues of the sails are called sheets and the lines connected the tack of the spinnaker are called guys. The position of these exemplary lines and many other lines are controlled by winches. 
     Referring to FIG. 1, a line  103  is held in place by wrapped it around the winch drum  105  several times. Tension on the first end  111  and the second end  113  creates friction between the winch drum  105  and the line  103 . The surface of the winch drum  105  may be textured to increase friction. When there is sufficient friction the line  103  moves as the winch drum  105  rotates. The winch  107  has an internal gear system that rotates the winch drum  105  when a center socket (not shown) at the top center is rotated. 
     A winch handle  121  has a socket (not shown), an arm  123  and a handle  125 . The socket of the winch handle  121  is releasably insertable into the center plug. By manually rotating the handle  125  around the winch  107 , the center socket is rotated driving the internal gearing and causing the winch drum  105  to rotate and the line  103  to move. The winch drum  105  is ratcheted so that it only rotates in one direction, typically clock-wise when viewed from above. A substantial amount of tension can be produced in the line  103  due the gearing of the winch  107 . 
     It is often necessary to quickly remove the line  103  from the winch  107 . In order to improve the speed which the line can be removed from the winch  107 , the winch handle  121  is first removed from winch  107  while tension is maintained on the line  103 . With the winch handle  121  removed the line  103  can be released from the winch  107  by pulling the line  103  straight up and off the winch drum  105  without fouling on the winch handle  121 . 
     A problem with winch handles is that they may be accidentally dislodged from the winches and become lost in the surrounding water when they fall off the boat. In order to reduce this problem, the locking which handle was developed. Referring to FIG. 2, a locking winch handle  221  inserted into a winch  207  is illustrated the winch socket  251  and winch handle plug  261  are typically splined such that when engaged, there is no relative rotation between the winch socket  251  and the plug  261  when the winch handle  221  is rotated about the winch  207 . The winch  207  has a splined socket  251  which is geared to rotate the winch drum  205  and an enlarged space below the splined socket  251 . The locking plate  263  is connected to a shaft  265  and is rotationally actuated by a switch  267  relative to the plug  261  and below the splines of the socket  251  is an open space  255 . 
     Referring to FIG. 3A, the bottom of the locking plate  363  is illustrated. In the normal position, the locking plate  263  is rotated relative to the splines of the plug  361  to be out of alignment with the splines of the socket  351  which locks the winch handle into the winch and prevents the accidental removal of the plug  261  from the socket  351 . The winch handle may have an internal spring that normally positions the locking  363  out of alignment with the splines of the plug  361 . Referring to FIG. 3B, when the switch is actuated, the locking plate  363  is rotated into alignment with the splines of the plug  361  allowing the plug  361  to be inserted or removed from the socket  351 . When a locking plate  363  mounted on the bottom of the plug  361  is aligned with the splines of the plug  361  the winch handle may be inserted or removed from the winch. 
     A problem with the rotating plate locking mechanism is that it utilizes a mechanism that requires manual manipulation in order to insert and remove the winch handle and is prone to failure. Further the rotating plate may be exposed to a salt water environment that can cause rotating shaft to seize within the plug preventing the rotation of the locking plate. If the plate mechanism malfunctions or seizes, it may be impossible to insert into or remove the winch handle from the winch. 
     What is needed is a winch handle that has a retention mechanism that does not require manual manipulation of a switch and does not have internal rotating components that can seize in corrosive environments. 
     SUMMARY AND OBJECTIONS OF THE PRESENT INVENTION 
     The present invention is a system for retaining a winch handle within a socket using a locking plate mounted to the bottom of the splined plug. The locking plate may be rectangular in shape and may extend away from the bottom of the plug at one edge. Normally, when the plug of the winch handle in inserted into the socket of a winch, the plug and socket have substantially the same center axis and the locking plate rests below the lower edge of the socket splines. During normal use, there is no tendency for the winch handle plug to fall out of the socket because only downward and rotational forces are applied to the grip of the winch handle. 
     An accidental impact with the winch handle may produce an upward force upon the bottom of the winch handle arm causing the plug to rotate within the winch socket. This rotation of the socket causes the locking plate to engage the lower edge of the socket splines. The interference of the locking plate and lower edge of the socket splines prevents the winch handle plug from sliding out of the winch socket which retaining the winch handle in the winch. 
     In an embodiment, a lower portion of the winch plug facing the arm is cut away. The cut away section of the plug allows the plug to rotate farther within the socket when an upward force is applied to the winch arm. The cutaway section of the plug also exposes a larger section of the locking plate and allows a larger area of the locking plate to interfere with the lower edge of the socket splines. 
     In an embodiment, the bottom portion of the locking plate is tapered, conical or hemispherical in shape which allows the winch handle plug to be more easily aligned and inserted into the socket. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which: 
     FIG. 1 illustrates a side view of a line coiled around a winch and a winch handle inserted into the winch; 
     FIG. 2 illustrates a cut away view of a winch handle inserted into a winch; 
     FIG. 3A illustrates a bottom view of a locking plate and plug inserted into a winch socket, wherein the locking plate is out alignment with the splines of the socket; 
     FIG. 3B illustrates a bottom view of a locking plate and plug inserted into a winch socket, wherein the locking plate is in alignment with the splines of the socket; 
     FIG. 4 illustrates a winch, winch handle and forces normally applied to the winch handle; 
     FIG. 5A illustrates a cross section of a winch and an embodiment of the inventive winch handle during normal use; 
     FIG. 5B illustrates a cross section of a winch and an embodiment of the inventive winch handle in the locked position; 
     FIG. 6A illustrates front view of an embodiment of the inventive winch handle plug; and 
     FIG. 6B illustrates side view of an embodiment of the inventive winch handle plug. 
    
    
     DETAILED DESCRIPTION 
     The following is a detailed description of the presently preferred embodiments of the present invention. However, the present invention is in no way intended to be limited to the embodiments discussed below or shown in the drawings. Rather, the description and the drawings are merely illustrative of the presently preferred embodiments of the invention. 
     The present invention overcomes the problems associated with a moving locking mechanism. The present invention utilizes a fixed plate that only engages the bottom edge of the socket splines to retain the winch handle plug in the splined socket of the winch when the winch handle is rotated vertically. 
     Referring to FIG. 4, an X-Y-Z axis is illustrated at the junction of the winch handle  421  and winch socket  451 . During normal use two forces are applied to the winch handle. A rotational force  471  is applied to the winch handle grip  425  in the Y direction as the operator rotates winch handle about the winch  407 . The rotational force causes a first torque to be applied to the plug about the Z axis. The torque is equal to rotational force x winch handle arm  423  length. Because the plug is configured to rotate about the Z axis, the rotational force  425  results in rotation of the drum  405 . A downward force  475  is applied to the winch handle grip  425  by the operator as well as by gravity in the Z direction. A downward force  475  causes a second torque to the plug about the Y axis. The plug does not move in the Z direction, thus the winch handle  421  is maintained in the X-Y plane. 
     As discussed, the winch handle plug is removably inserted into the winch socket. 
     In order for the plug to fit easily into the socket, the outer surfaces of the plug are slightly smaller than the inner surfaces of the socket. Thus, there is a gap between the plug and socket. Referring to FIG. 5A, in the normal operation, the plug  561  and socket  551  contact each other at points  581  and  583  because a downward force  593  is applied to the winch handle  521  by the operator. The plug and socket are not in contact at points  587  and  585 . Because the plug does not contact the socket at point  585 , this section of the plug is non-functional during normal use and the socket  561  can include a cut away section  591  without interfering with the normal operation of the winch handle  521 . 
     Winch handles may be accidentally dislodged from the winch when the winch handle is knocked upwards. In order to knock the winch handle upwards, contact must be made to the lower surface of the winch handle. This upward impact may result from a person, a tensioned line or any other physical object. This contact most commonly occurs below the winch handle grip section because this is the portion of the winch handle that protrudes over the outer edge of the winch. An upward force below the grip section of the winch handle results in a rotation of the winch handle about the Y axis which is opposite in direction to the normal downward force. 
     Referring to FIG. 5B, the inventive winch handle socket  561  has a cut away section  591  and a fixed lower plate  563 . When however an upward force  595  is applied to the grip portion of the winch handle, the cut away section  591  allows the winch handle plug  561  to rotate about the Y axis farther than a plug not having the cut away section  591 . When the plug is fully rotated the lower plate  563  engages the lower edge of the splines of the socket  551 . The engagement of the lower plate  563  and the lower edge of the socket  551  splines prevents the winch handle  521  from being removed from winch  507 . 
     In an embodiment, portions of the plug splines are removed in order for the plug to rotate within the socket allowing the lower plate to engage the lower edge of the socket splines. Referring to FIGS. 6A and 6B, an embodiment of the plug having a cut away section  691  and some partially removed splines  697  is illustrated. The cut away section  691  and removal of portions of the splines  697  allows the plug  661  to rotate within the socket, which allows center axis of the plug  661  to rotate into misalignment with the center axis of the socket. If there is a sufficient gap between the plug  661  and socket, a portion of the plug may not need to be removed (the cut away section  691 ) and the plug splines  697  may not need to be partially removed. 
     In order for an operator to remove the inventive winch handle from a winch, the winch handle may be grasping at the plug section and pulled up to remove the plug from the socket. By pulling up at the plug section, the weight of the arm and grip will rotate the socket so that the lower plate does not engage the lower edge of the splines. The operator may also remove the winch handle by grasping the arm section and exerting a rotational force that prevents the lower plate from engaging the lower edge of the splines while pulling up on the winch handle. 
     As discussed, the winch handle plug must be positioned directly above the winch socket and the splines of the plug must be aligned with the splines of the socket to insert the plug into the socket. The lower plate may be a planar piece or a three dimensional component having a tapered, conical, curved or hemispherical shape. In an embodiment, the lower plate is planar and the inventive winch handle is inserted into the winch socket like a normal non-locking winch handle. In an alternative embodiment, the inventive lower plate is tapered, conical, curved or hemispherical in shape. By using a tapered, conical or hemispherical lower plate the plug is more easily aligned with the socket because the smaller cross sectional area of the bottom of the lower plate will more easily engage the socket opening. The smaller cross section bottom engages the socket and the tapered or curved sides of the lower plate assist in aligning the plug with the socket. This is similar to the difference between placing a cylinder and a sphere into a hole. It is easier to insert a sphere in a close fitting circular hole that a cylinder. The added material of the tapered, conical or hemispherical lower plate will also be structurally stronger than a planar lower plate. Referring to FIGS. 6A and 6B, the locking plate  663  has an exposed surface that is spherical. 
     There are several suitable materials for the inventive winch handle. In the preferred embodiment, the winch handle plug is made of a durable metal such as aluminum, stainless steel, bronze, titanium and any other suitable metal. In the preferred embodiment, the winch handle plug and lower plate are made of the single piece of metal. It is also possible for the lower plate to be a separate piece and a different material that is attached to the plug. The lower plate may be attached to the plug by a fastener, adhesive, welding, bolt(s) or any other suitable attachment mechanism. Because the lower plate is subjected to a substantial amount of abrasion due to impact with the winch socket, the lower plate material may be coated with a protective layer. The locking plate maybe plated or include a plastic layer which reduces the insertion friction. The locking plate may also be replaceable if the locking plate is broken or heavily worn. 
     The arm of the winch handle may be made out of the same piece of material as the plug or it may be a separate piece made of the same material as the plug or a different material. The arm may also be a composite of materials such as plastic, carbon fiber, fiberglass, and metals. The arm may also be a hollow structure or a construction that allows the winch handle to float in water. Specifically, if the weight of the winch handle divided by the volume of the winch handle is less than the density of water or salt water, the winch handle will float. The arm may be attached to the plug by fasteners, an adhesive, welding, bolt(s) or any other suitable attachment means. 
     The winch handle grip may rotate about a spindle that is attached to the winch handle arm. Bearings and/or bushings may be used within the grip to minimize the rotational friction of the grip during normal use. The bearings and bushings may be steel, plastic or any other suitable material. The grip is preferably plastic, metal or a combination of materials. The grip may be configured to be grasped by a single hand or two hands. Preferably, all of the materials used in the inventive winch handle are resistant to corrosive salt water environments. 
     In the foregoing, a winch handle retention system has been described. Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.