Handling: hand and hoist-line implements – Hook – hoistline – or grab type – Load releasing means
Reexamination Certificate
1999-06-28
2001-05-29
Kramer, Dean J. (Department: 2167)
Handling: hand and hoist-line implements
Hook, hoistline, or grab type
Load releasing means
C294S082210, C024S600200
Reexamination Certificate
active
06237977
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to pelican hooks and, more particularly, to an over-center pelican hook which connects a cable to an anchoring member and has a hinged keeper that is not loaded when the pelican hook is closed and engaged in tension with the anchoring member. The hinged keeper also has an extractor claw to assist in releasing the pelican hook from engagement with the anchoring member.
2. Background Art
Conventional pelican hooks for use on fencing or railing are well known in the art, particularly in marine applications. Pelican hooks are used on boat railings to allow a section of the railing to be opened and closed for the ingress and egress of passengers or cargo. Primarily, the railings in boat applications are for safety and prevent passengers from falling overboard when the railing is closed. Similar applications of pelican hooks may be found in railings for temporary staircases, bleachers, or pedestrian aisle guide rails, where arrangements of the chains, cables or ropes are often changed. Marine applications demand that the hook function properly and retain its strength in harsh marine environments that easily corrode metallic components.
In general, a pelican hook is used by first fixing the hook to the moveable portion of the gate, fence, railing or, typically, a cable. An eye in the hook allows the hook to be engaged with an anchoring member such as an eyelet on a rigid fence post or an adjacent railing cable. The pelican hook is equipped with a hinged keeper that partially defines the enclosed eye in which the eyelet of the anchoring member is retained, and which allows the hook to be disconnected from the eyelet.
There are, however, drawbacks associated with pelican hooks currently in use. A commonly-used pelican hook is found in U.S. Pat. No. 3,938,844 to Johnson. This hook has a hinged keeper that is placed under tension by an anchoring member bearing against the hinged keeper during normal use of the pelican hook. The tensile load would cause the hinged keeper to open but for the resistance of a retaining device that keeps the hinged keeper closed. The hinged keeper is opened by simultaneously relieving the tension transferred from the keeper to the retaining device and releasing the retaining device from the keeper.
In high-tension applications, disconnecting the pelican hook from the anchoring member requires strength and dexterity to release the retaining device, and may be difficult and even dangerous. Additionally, the operational life of the hook may be shortened by deterioration of the hook components due to high tensile and shear forces between the components. Frictional wear may be accelerated when the hook is used in a salty and sandy marine environment.
It is an object of the present invention to provide a pelican hook that does not have a tendency to move toward an open position when the pelican hook is connected in tension to an anchoring member.
It is a further object of the present invention to provide a hook that provides a safe, conventional method of releasing the hook from the anchoring member.
Yet another object of the present invention is to reduce the load on the retaining device, for example a plunger pin, thereby reducing wear and increasing the useful lifetime of the pelican hook.
SUMMARY OF THE INVENTION
According to an aspect of the present invention, an over-center pelican hook for selectively engaging and releasing a first object from a second object includes a hook body having an attachment means disposed at a first end for fixably attaching said hook body to said first object. A hook-shaped body portion is disposed at an opposite second end of the hook body for engaging the second object and carrying a tensile load between the first and second objects. A hinged keeper has a first end and a second, free end, and is pivotally coupled at the first end to the hook-shaped body portion of the hook body. The free end of the hinged keeper is moveable between a closed position, which forms a closed eye with the hook-shaped body portion for retaining the second object in the eye, and an open position, where the free end is displaced away from the hook-shaped body portion to open the eye and thereby permit the second object to be released from the pelican hook. A retaining device selectively retains the hinged keeper in the closed position.
One advantage of the present invention is that there is no tendency for the pelican hook to move to the open position when placed under load by the anchoring member.
Another advantage of the present invention is that wear of the retaining device is significantly reduced because the retaining device is not loaded when the pelican hook is engaged with the anchoring member.
Yet another advantage of the present invention is realized by the use of the plunger pin, which retracts into the hook body as the hinged keeper is closed, and automatically locks the hinged keeper once the hinged keeper is in the closed position.
These and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of best mode embodiments as illustrated in the accompanying drawings.
REFERENCES:
patent: 23985 (1859-05-01), Mealey
patent: 343037 (1886-06-01), Klinkner
patent: 1278494 (1918-09-01), Nesbit
patent: 1636209 (1927-07-01), Bergsten
patent: 2091477 (1937-08-01), Grau
patent: 4093293 (1978-06-01), Huggett
patent: 4401333 (1983-08-01), Merry
patent: 4632443 (1986-12-01), Miller et al.
patent: 5634246 (1997-06-01), Jermyn, Jr.
C. Sherman Johnson Co.
Kramer Dean J.
McCormick Paulding & Huber LLP
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