GB2271146A

GB2271146A - Releasable hook for heaving and lowering of a life boat or similar rescue means

Info

Publication number: GB2271146A
Application number: GB9319935A
Authority: GB
Inventors: Erik Buer
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-10-01
Filing date: 1993-09-28
Publication date: 1994-04-06
Anticipated expiration: 2013-09-28
Also published as: GB9319935D0; GB2271146B; NO923825D0; NO923825L; NO175577B; NO175577C

Abstract

A releasable hook for heaving and lowering of a life boat or the like by means of a rope, wire or similar, comprising a carrier (6) to be mounted on the boat, a hook (3) for receiving the rope, pivotally supported in the carrier about bolt 15. A closing member (1) is pivotally supported in the carrier and is adapted to close the hook mouth and can be pivoted in order to open the hook mouth. The closing member (1) comprises at least one arcuate groove or slit (10) and having its center of curvature offset from its own pivot axis (12), said center being situated in the pivot axis of a locking lever (2) when the closing member is in its closing position, and the locking lever (2) is equipped with at least one element (11) which can engage the groove or slit (10) when the closing member (1) is in its closing position, in order to prevent pivoting of the closing member. The element or elements (11) is/are situated outside of an open end of the groove or slit (10) when the locking lever (2) is in the locking position. The locking lever (2) can be operated remotely via rod (5) and cable means not shown. <IMAGE>

Description

Releasable attachment device for heaving and lowering of a life boat or similar rescue means.

The present invention relates to a releasable attachment device for heaving and lowering of a life boat or similar rescue means by means of a rope, wire or similar, comprising a carrier to be firmly mounted on the boat or similar, a hook for fastening of the rope, pivotally supported in the carrier and lockable in a supporting position by means of a locking lever which is pivotally supported in the carrier, whereby the hook is releasable for pivoting to an open position by pivoting of the locking lever, which is coupled to a drive mechanism, and a closing member is pivotally supported in the carrier and is adapted to close the hook mouth, and can be pivoted in order to open the hook mouth.

The supporting position of the hook is the pivotal position where the hook is situated for carrying load, i.e. the life boat or similar.

For heaving and lowering of a life boat or similar two such attachment devices are used, one at each end of the boat. The attachment devices can be coupled to a common mechanism in order to be released, whereby both of the attachment devices are released simultaneously in a single operation. Release takes place after the boat has been launched in the sea. For heaving and lowering are used ropes or wires, or chains, and a hoisting mechanism.

A danger by the use of such attachment devices is that the ropes, wires or similar can be hooked onto the hooks also when the hooks have not been moved completely to the supporting position and without being adequately locked. Closing members are used whose only purpose is to prevent that the rope, wire or similar inadvertently-is hooked off from the hooks after having been hooked on, and the closing members can be pivoted away from the hook mouth for hooking on, irrespectively of the pivotal position in which the hooks are situated. Attempts have been made in order to achieve a larger degree of safety, among else by providing means for preventing that the locking lever can be moved to the locking position unless the hook has been moved to the supporting position.

However, accidents occur during use of such attachment devices, in that the boat for instance is dropped by one of the attachment devices after having been heaved more or less up from the sea. The reason why a hook is not moved completely to the supporting position and locked in that position prior to hooking on a rope or wire can be inferior maintenance, inferior lubrication, paint which prevents free movements of movable parts, and moreover the crew may have unsufficient knowledge of the use of the attachment devices. Among else, marking in the form of indicators showing that the hooks are completely locked are used, but accidents nevertheless occur, because the crew does not always know the meaning of these indicators.

According to the present invention this problem has been solved mechanically, whereby it is physically impossible to hook on a rope, wire or similar on the hook unless the hook has been moved completely to the supporting position and has been adequately locked in the supporting position.

The attachment device according to the invention is characterized in that the closing member comprises at least one groove or slit having the shape of a circular arc and having its center of curvature offset from its own pivot axis, said center being situated in the pivot axis of the locking lever when the closing member is in its closing position, that the locking lever is equipped with at least one element which can be inserted in the groove or slit when the closing member is in its closing position, in order to prevent pivoting of the closing member, and that the element or elements is/are situated outside of an open end of the groove or grooves/slit or slits when the locking lever is in the locking position.

This involves that as long as the locking lever is not in the locking position, but is situated with the element or elements more or less inserted in the groove or grooves/slit or slits in the closing member when this is in its closing position relatively to the hook mouth, pivoting of the closing member and consequently also hooking of a rope, wire or similar onto the hook are prevented. In order to release the closing member for permitting hooking the locking lever must be pivoted to the locking position, whereby the element or elements is/are moved out of the groove or grooves/slit or slits in the closing member, and such pivotal movement is only possible when the hook has been moved completely to the supporting position. Thereafter hooking can take place, by pivoting of the closing member to an open position relatively to the hook mouth.

By providing that the locking lever is in its locking position when the element or elements has/have been moved out of the groove or grooves/slit or slits in the closing member an adequate safety is in the principle achieved. An additional safety may, however, be achieved by providing an obstructing knob on the locking lever or locking shaft, in such a position that the knob engages the hook when this is adjacent, but not completely in the supporting position, whereby the knob only releases the locking lever and the locking shaft for pivotal movement to the locking position when the hook is in the supporting position. Only in this supporting position of the hook the closure member is released in order to be opened for hooking.

The invention will in the following be explained more detailed, with reference to the accompanying drawings, showing an example of a device according to the invention.

Fig. 1 shows an attachment device in accordance with the invention, in a side view perpendicularly on the main plane of the carrier, in a condition where the hook is in the supporting position but without being locked, and the closing member closes the hook mouth.

Fig. 2 shows the attachment device in the same condition as in Fig. 1, seen at an angle from the side.

Fig. 3 shows the attachment device in a condition where the hook is locked in the supporting position, while the closing member is released for being able to pivot.

Fig. d shows the attachment device in a condition where the hook is locked in the supporting position, while the closing member has been pivoted to the open position.

Fig. 5 shows the attachment device in a condition where the hook is released.

The attachment device of the example shown comprises a carrier 6, mainly in the form of two parallel plates, on and between which the remaining elements are mounted. The plates are held mutually spaced by means of bolts or similar. This appears most clearly from Fig. 2. In its condition ready for use the carrier 6 can be such mounted that it protrudes partially above and partially below a deck 19 in a boat, as shown in Figs. 1 and 3 to 5. A hook 3 is mounted between the plates and is pivotable around a bolt 15. Inside a cover 17 at one side of the carrier 6 a locking lever 2 is in a fixed connection with a locking shaft 9, which is journalled for rotation in the carrier 6. Through a bolt 7 the locking lever 2 is connected to a drive mechanism 4, which comprises a rod 5 coupled to a not shown drive cable, and the rod 5 extends through an aperture 20 in the deck 19.The carrier 6 may be stabilized at its bottom, by a stand 16 indicated by dotted lines.

A closing member 1 for the hook mouth is pivotally journalled on a bolt 12 which is fastened to the carrier 6, and the closing member 1 is in Figs. 1 and 2 shown locked against pivotal movement, in that a pin 11 at the free end of the locking lever 2 is situated in a groove or slit 10 shaped as a circular arc in the closing member 1. In this position of the closing member 1 the centre of curvature of the groove or slit 10 coincides with the pivot axis of the locking lever 2 and the locking shaft 9, and movement of the pin 11 in the groove 10 can take place by pivotal movement of the locking lever 2 and the locking shaft 9, because the center of curvature of the groove or slit 10 coincides with the pivot axis of the locking shaft 9.The hook 3 is situated in the supporting position, i.e. the position taken by the hook 3 when it carries a life boat or another rescue means which hangs in a rope, wire or similar, but the hook is not locked.

Locking of the hook 3 in the supporting position is carried out by pivoting the locking lever 2 and the locking shaft 9 to the position shown in Fig. 3. This pivotal movement moves the pin 11 out of the groove or slit 10 in the closing member 1, and the closing member is released for pivotal movement about the axis of the bolt 12.

Locking of the hook 3 in the supporting position is caused by the locking shaft 9, which has a flattened portion. Prior to pivoting the locking shaft 9 to the locking position the flattened portion is situated in such a position that the inner end of the hook 3, between the plates of the carrier 6 and remote from the hook portion, may pass the flattende portion of the locking shaft 9 and be pivoted to and from the supporting position. However, after the hook 3 has been moved to the supporting position and the locking shaft 9 has been pivoted to the locking position together with the locking lever 2 the flattened portion of the locking shaft 9 is no longer situated in such a position that the inner end of the hook can pass the locking shaft 9, and pivotal movement of the hook 3 away from the supporting position is prevented.In this condition the flattened portion is situated adjacent the inner end of the hook, in a direction nearly crosswise of the direction in which the inner end of the hook has to move from the supporting position whereby, when the hook is wholly or partly loaded by the weight of a life boat or similar, a portion of the inner end of the hook will press against the flattened portion of the locking shaft 9, and the hook is prevented from pivoting away from the supporting position. The locking shaft 9 may for instance comprise a half of a shaft in the flattened portion, i.e. that the locking shaft 9 approximately has a semicircular cross section in this portion.

Fig. 4 shows the hook 3 in the same position as in Fig. 1 to 3, but the closing member 1 has been pivoted to the open position for hooking of a rope, wire or similar onto the hook 3 for heaving of a boat. The closing member 1 may be shaped and pivotally journalled in such a manner that is has to be swung manually away from the closing position, and such that it swings automatically to the closing position when not held, because the closing member 1 is not balanced about the bolt 12.

Thus, the presupposition for enabling pivotal movement of the closing member 1 to the open position shown in Fig. 4 is that the hook 3 is situated in the supporting position and is locked in this position in that the locking lever 2 and the locking shaft 9 have been pivoted to the locking position, where they prevent that the hook 3 can pivot away from the supporting position. Only in this condition hooking of a rope, wire or similar onto the hook 3 is possible.

In the embodiment shown the closing member 1 comprises a surface 22 having the shape of a circular arc, and the surface 22 ends in a notch 23. When the closing member 1 is pivoted from the closed position shown in Fig. 3 to the open position shown in Fig. 4 the surface 22 will pass the pin 11 on the locking lever 2, and in the open position of the closing member 1 the pin 11 is inserted in the notch 23, as shown in Fig. 4. Thereby the locking lever 2 is prevented from pivoting away from the locking position when the closing member 1 is in the open position.

A stopper 13 may be mounted in the carrier 6, shaped as an arm and pivotally journalled on a bolt 14. The stopper 13 can pivot freely and has such a shape that it seeks to pivot towards a position where the arm engages the flattende portion on the locking shaft 9, in order to prevent pivotal movement of the locking shaft. This takes place when the hook 3 has not been pivoted towards the supporting position. However, when the hook 3 is pivoted to the supporting position the inner end of the hook forces the arm on the stopper 13 away from its locking position relatively to the flattened portion of the locking shaft 9.

As an additional safety precaution, in order to prevent the locking lever 2 and the locking shaft 9 from pivoting to the locking position unless the hook has been completely pivoted to the supporting position, an obstructing knob 8, shown in dotted line in the Figs. 1, 3, 4 and 5, can be fastened to the locking lever 2 or the locking shaft 9, in such a position that the knob 8 engages the hook 3 and prevents pivotal movement of the locking lever 2 when the hook 3 is not completely pivoted to the supporting position. The obstruction caused by the knob 8 does not cease until the hook 3 is in the supporting position, wherupon the locking lever 2 can be pivoted to the locking position.

In the embodiment shown the closing member 1 is made of two parallel plates, as it best appears from Fig. 2, one plate being situated on either outer side of the carrier 6. A crosspiece 21 (Fig. 2) connects the plates and can also contribute with its weight to pivot the closing member 1 to the closing position. Moreover, the closing member 1 is equipped with two pins 18 which prevent hooking of a rope, wire or similar into the space between the closing member 1 and the hook 3. In order that these pins shall not prevent opening of the closing member 1 a cutout 24 has been made in each of the plates which constitute the carrier 6. It will be appreciated that the space may be blocked by other elements than pins.

Two or more attachment devices can be used for each boat, and release of the hooks 3 can take place simultaneously for both or all of the attachment devices, in that the drive mechanisms 4 of both or all of the attachment devices are interconnected in a per se known manner.

Claims

1. A releasable attachment device for heaving and lowering of a life boat or similar rescue means by means of a rope, wire or similar, comprising a carrier to be firmly mounted on the boat or similar, a hook for fastening of the rope, pivotally supported in the carrier and lockable in a supporting position by means of a locking lever which is pivotally supported in the carrier, whereby the hook is releasable for pivoting to an open position by pivoting of the locking lever, which is coupled to a drive mechanism, and a closing member is pivotally supported in the carrier and is adapted to close the hook mouth, and can be pivoted in order to open the hook mouth, c h a r a c t e r i z e d i n that the closing member comprises at least one groove or slit having the shape of a circular arc and having its center of curvature offset from its own pivot axis, said center being situated in the pivot axis of the locking lever when the closing member is in its closing position, that the locking lever is equipped with at least one element which can be inserted in the groove or grooves/slit or slits when the closing member is in its closing position, in order to prevent pivoting of the closing member, and that the element or elements is/are situated outside of an open end of the groove or grooves/slit or slits when the locking lever is in the locking position.

2. A device according to claim 1, c h a r a c t e r i z e d i n that an obstructing knob is fastened to the locking lever i such a position that the knob comes to an obstructing contact with the hook when this is situated adjacent but not completely in the supporting position, whereby the knob is not released for permitting pivoting of the locking lever until the hook is in the supporting position.

3. A device according to claim 1 or 2, c h a r a c t e r i z e d i n that the closing member at the open end of the groove or grooves/slit or slits comprises a surface mainly crosswise of the direction of the groove or grooves/slit or slits, said surface being moved along and adjacent the element or elements on the locking lever when the closing element is pivotally moved to the open position, whereby the surface prevents pivotal movement of the locking lever away from the locking position.

4. A device according to claim 1, 2 or 3, c h a r a c t e r i z e d i n that the element on the locking lever is a pin.

5. A device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.