Ships – Sail or control means therefor – Fastening device for sail
Reexamination Certificate
2001-05-25
2003-04-01
Morano, S. Joseph (Department: 3617)
Ships
Sail or control means therefor
Fastening device for sail
Reexamination Certificate
active
06539885
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to shackles used for joining two members under tension and more articularly to a locking shackle apparatus and a locking mechanism for the same.
BACKGROUND OF THE INVENTION
The technique of attaching two members together under tension, such as a rope or cable, can be accomplished with the use of a shackle. In many instances such as in the field of sailing, it is desired to reduce to a minimum the distance between the attachment point of the line and the latching throat of the shackle. Such an instance occurs on a halyard when desiring to hoist the sail to the extreme top of the mast. In other instance, it is desired to reduce to a minimum the overall width and profile of the shackle such as to allow the shackle to pass through a Genoa block or other tight passage. In both cases, the desired arrangement consists of a thimble-like snap shackle onto which the line or cable can be directly spliced around its body.
Thimble-like rope type snap shackles such as described are commercially available but have many drawbacks. First, they are often subject to violent flogging and impact against a mast or are repeatedly dragged across a deck. Existing snap shackles are extremely prone to accidentally popping open under such circumstances. This accidental opening is so common that the current “state of the art” procedure in the sailing industry has been to wrap masking tape around the shackle. A second drawback with current thimble type shackles is the difficulty in quickly opening or closing the shackle with limited sense of feel or sight. In many instances, sailors are in rough seas or are wearing gloves and it is not always possible to physically look at or feel the shackle when operating it. Existing thimble type shackles require the plunger knob to be precisely aligned before it can be operated, resulting in dangerous or inefficient situations. A third problem with existing thimble type rope shackles and with plunger pin shackles in general is that a high side loading is applied to the plunger pin. Frequently the plunger pin becomes permanently bent and the shackle is inoperative. Finally, a fourth problem with rope shackles and other shackles in general is the binding of the hook against deformed or fretted material along the inside of the clevis. After extended use, the constant pressure and sliding of a fitting latched to the shackle throat tends to deform and erode the material along the inside walls of the clevis slot. Eventually the clearance between the clevis wall and the pivoting hook decreases to a point where the hook begins to bind and no longer hinges correctly.
The earliest attempt to solve some of these problems was with a J-Lock shackle containing a plunger pin. However, these shackles did not have any method of locking the pin into place. As a result, the plunger pin would often pop open during either severe flogging or when dragged across the deck. These old J-Locks were cast from bronze and were produced at least 40 years ago and by some account, perhaps up to 100 years ago.
The next attempt to improve the shackle was a new design on the J-Lock that was made about 30 years ago. In this design, the knob on the plunger pin contained a notch, which had to be turned to the correct orientation so as to allow a keyway on the body to line up with the slot in the knob. To open the shackle, the knob would be turned to the correct orientation so as to allow the notch in the knob to pass over the keyway type protrusion on the body. To close the shackle, the notch would again be lined up, the plunger pin snapped shut, and the knob then turned to some random orientation so as to misalign the notch with the keyway protrusion.
While this J-Lock design was an improvement over the earliest version, there are several drawbacks with this design. First, during flogging, the knob tended to rotate from vibration and eventually work its way to the orientation such that the notch and keyway line up. Then, the shackle would pop open. Second, when pulled over a deck, the knob tended to roll and invariably rotate to the “bad” orientation whereas it eventually pops open. For years, the solution to this rotation and vibration problem has been to wrap tape around the knob and shackle so as to lock it in place. The tape must be ripped off whenever the shackle must be opened, and re-tapped the next time it is shut. This is very inconvenient and can be very dangerous to sailors in rough waters, but has been the only way to prevent opening during flogging or handling. The procedure has been the “state of the art” for as long as most sailors can remember.
Thirdly, this J-Lock design is very difficult to quickly line up the notch with the keyway so as to open the shackle in a hurry. When the existing J-Lock is snapped shut and the knob rotated to a random position, it is difficult to find the position that allows the notch to line back up again. One must look or feel for the notch and keyway orientation, usually whilst the user is with gloves and cold fingers. During a sailboat race it is next to impossible to visually observe the orientation of the knob. Thus, the alignment must be done by sense of feel alone and becomes very frustrating.
A fourth problem with the existing J-Lock design pertains to the alignment of the knob.
In many cases, it is desirable to be able to quickly shut the shackle by snapping the hook shut as is done on conventional pull pin shackles. This quick shutting feature is particularly desirable during fast paced sailboat races. With the existing J-Lock, one must first pre-align the knob notch with the protrusion on the body. Assuming no change in orientation occurs, one should then be able to simply snap the hook shut. The hook pushes onto the free end of the pull-pin, forcing the knob to lift up past the body protrusion and then snaps back shut again. This is what would ideally be desired. However, with the existing J-Lock design, even the pre-alignment does not always allow the shackle to operate as desired. The contact of the hook with the free end of the pull-pin sometimes imparts a rotation onto the pull-pin which in turn misaligns the notch on the knob with the protrusion on the body. As a result of this misalignment, the knob jams into the bottom of the body protrusion and will not snap shut. Such a problem is extremely frustrating and causes the loss of valuable time in a sailboat race.
A fifth problem exists with the current J-Lock shackle. While loading a substantial amount of force onto the pull pin, the pull pin tends to bend and become permanently deformed. It any bending occurs, the pull pin cannot be slid open or closed and the shackle is destroyed.
And finally, the existing J-Lock hook geometry at the location where the hook pivots through the clevis case fosters fretting and destroys the shackle with continued use. When the hook is shut and the shackle loaded, the loaded member exerting force against the inside surface of the J-Lock is usually a metal ring or other metal fitting. After continued use, fretting and wear on the body clevis and hook surface causes the clevis and hook base material to “roll over” on the edges. Burrs caused from this edge “roll over” eventually reduce the clearance so much that the hook binds inside the clevis and will no longer open or shut smoothly.
Therefore a need exists in the art for an improved design of a shackle that will not accidentally open when exposed subject to violent flogging and impact against a mast or when repeatedly dragged across a boat deck, that overcomes the difficulty in quickly opening or closing the shackle with limited sense of feel or sight, that does not require high side loading to be applied to the plunger pin, and is not vulnerable to binding of the hook against deformed or fretted material along the inside of the shackle clevis.
SUMMARY OF THE INVENTION
The present invention relates to a shackle with a locking mechanism, the shackle is composed of a shackle body having a hook opening with a shackle pivot hole, a plunger pin opening for a plunger pin with
Morano S. Joseph
Olson Lars A.
Ritchie William B.
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