Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings, in which:
In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. Throughout this description, the preferred embodiment and examples shown should be considered as exemplars, rather than as limitations on the present invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s).
The present invention is directed to a lifeboat disengagement system for supporting and releasing twin fall boats, wherein the disengagement system provides positive locking under load until a release handle is pulled that disengages a pair of hooks simultaneously. Unlike conventional systems, the lifeboat disengagement system of the present invention features a pair of stable hooks, wherein the load of the lifeboat locks the hooks such that they do not release under load. In other words, the disengagement system is designed so the load of the boat is not employed to open the hook. This locking design protects the occupants of the boat while it is being lowered into the water or while it is being lifted out of the water. Even if an operator, in error, attempts to pull on the hook release lever while the boat is suspended in the air, the stable hooks will not open. In addition, should a part fail or malfunction, the hooks will not open. Once the boat is afloat in the water, the operator may then pull the hook release lever and open the hook.
According to the principles of the present invention, the stable hook design set forth herein permits the lifeboat floating in the water to replace, or to be used in lieu of, a troublesome conventional hydrostatic release valve. Advantageously, the hooks of the invention include less parts that conventional hooks, and are therefore less complex in design and easier to maintain. Additionally, the hooks offer the seafarer greater safety than that afforded by conventional hooks having a hydrostatic release valve. The hooks of the invention provide positive locking under load because of a load over center design, wherein the load is in line with the center of hook rotation, thereby preventing the hook from opening inadvertently and eliminating the need for a hydrostatic device. The hooks of the invention are also relatively simple to operate in that: (1) if the operator can pull the hook release handle and move it, the boat is safely in the water, afloat and the hooks will open; or (2) if the operator pulls on the hook release handle and cannot move it, the boat is suspended in the air and the hooks will not open. 100291 Regulation requires that in an emergency the hook design provides an ability to release the hooks when under load. According to the invention, this is accomplished by manually installing an additional ratchet lever on an exterior nut. The hooks can be reloaded even in the locked condition. In the system of the invention, a pair of hooks is mounted on a top surface of a lifeboat. Each hook may include a housing comprising a metal plate manufactured or bolted to the lifeboat, wherein the housing is provided with an independent servicing or hoisting flange having a circular opening for attaching to and lifting of the lifeboat.
Each hook that is utilized as a connection between a hoist and the lifeboat is rotatably pinned between a pair of plates which form the housing. The housing may be provided with a covering to prevent environmental contamination or damage. The hook includes an engaging surface that contacts the cable or hoisting ring. Specifically, the engaging surface includes the shaped portion of the hook, and is positioned such that, upon release and rotation of the hook, the face of the housing assists in the positive disengaging of the ring from the hook. A lock may be provided and positioned, such that in a released configuration, the lock either contacts or comes very close to contacting a distal end of the hook, thereby preventing the ring from accidentally being separated from the hook. In addition, a biasing device is positioned such that the securing function can be overcome easily by pressure during inserting of the ring, but cannot be overcome by the reverse motion.
According to the invention, each hook has a pivot point positioned such that the engaging surface for the hook and the housing cooperate to produce a vertical relationship between the pivot point of the hook and the contact point of the attaching ring with the hook surface. The engaging surface may be dimensioned such that the surface forms a constant radius arc, independent of rotation of the hook, about the pivot point of the hook. In operation, the hook is placed in its locked position, and a ring is placed through the exposed portion of the hook. The over center link position locks the structure preventing the hook from becoming disengaged upon accidental loss of tension in the cable supporting the ring and the remaining portions of the apparatus are locked in position by placing of a load on the ring. The links tend to remain in their extended condition under the load until such time as the load becomes sufficiently small such that the operator may pull the release handle such that the hooks disengage from the rings contained therein.
Referring to
The lifeboat disengagement system 100 of the invention may be employed for a variety of purposes such as moving and servicing lifeboats and other equipment. In operation, the lifeboat release assembly 110 is used to disengage the lifting links 120 simultaneously from stable hooks 118 of corresponding hook assemblies 115. More particularly, each hook assembly 115 comprises a hook 118 that is positioned between a pair of vertical plates 125 (which form a housing) by way of a shaft 130 such that the hook 118 is capable of rotating about the shaft 130. According to some embodiments, the housing may be provided with a covering to prevent environmental contamination or damage. The hook 118 includes an engaging surface 135 that is provided with a predetermined shape. In the illustrated embodiment, the engaging surface 135 is arcuate and is formed at a substantially constant radius from the shaft 130. The engaging surface 135 is positioned such that the face of the housing assists in the positive disengaging of the hoisting ring 120 from the hook 118 upon release and rotation of the hook 118.
One or both of the plates 125 is provided with an extension 140 which is drilled to form a lifting eye 145 suitable for hauling, hoisting or otherwise positioning the lifeboat or other equipment attached to the hook assembly 115. Each plate 125 is provided with a release surface which is vertically extended and curved relatively toward the rearward portion of the hook 118. During disengagement, the release surface 150 acts to positively disengage the hoisting ring 120 or other structure held by the hook 118 on its engaging surface 135. Additionally, each plate 125 is drilled at its forward end, and a pin 155 is provided for rotatably connecting a counter weighted latch 160. In the engaged configuration depicted in
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In
According to a preferred implementation, the lifeboat release assembly 110 is disposed inside the lifeboat such that the release handle 235 is an internal device. Existing lifeboats may be retrofitted by installing the lifeboat disengagement system 100 of the invention with limited modification to the existing lifeboat structure. Additionally, less motion is required to open and close the hooks 118. Specifically, the linear motion of the handle is converted to the rotary motion of the links, and then back to the linear motion of the pull plate 260. According to some embodiments, the release handle 235 must only be pulled approximately 4 inches to fully open the hooks 118. All moving parts of the lifeboat release assembly 110 are contained within the housing 215, thus preventing the interference of moving parts. If the operator is able to pull the hook release handle 235 and move it, then the lifeboat is safely afloat in the water, and the hooks 118 will open. However, if the operator pulls on the hook release handle 235 and cannot move it, then the lifeboat is suspended in the air and the hooks 118 will not open. To close the hooks to the normal position illustrated in
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The present invention has been described above in terms of presently preferred embodiments so that an understanding of the present invention can be conveyed. However, there are other embodiments not specifically described herein for which the present invention is applicable. Therefore, the present invention should not to be seen as limited to the forms shown, which is to be considered illustrative rather than restrictive.