GB2417521A

GB2417521A - Hook having spring biased locking dog and pulling element

Info

Publication number: GB2417521A
Application number: GB0517446A
Authority: GB
Inventors: Jack Ivan Braten
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-27
Filing date: 2005-08-26
Publication date: 2006-03-01
Also published as: GB0517446D0; NO20043578D0; NO327971B1; NO20043578L

Abstract

A hook 1 is arranged to be operated by means of manipulator arms connected to an R.O.V. The hook opening 9 is provided with a spring-loaded looking dog 10 which is arranged to block the hook opening 9 against uncontrolled release of a lifting implement out through the hook opening 9. The locking dog 10 is connected to a pulling element 25 extending through a bore 20 in the hook 1. The pulling element 25 is arranged to rotate the locking dog 10 from a first position, in which the hook opening 9 is blocked, into a second position, in which the hook opening 9 is open. The bore 20 is provided with bore openings 21, 22 which have a larger extent than a portion of the bore 20 located between said bore openings 21, 22. Between the hook body 2 and a lifting eye 7, the hook 1 is provided with a hook shaft 5, which is provided, at least in one portion, with a non-circular cross-section in order to prevent relative rotation consequent on little friction between the hook shaft 5 and a gripping implement.

Description

241 752 1

A LIFTING HOOK DEVICE AND METHOD OF OPERATING SAME

The present invention relates to a lifting component of a lifting device. More particularly, it concerns a lifting hook s which is provided with a locking dog connected to a pulling element which preferably runs through a portion of the lifting hook and which is arranged to rotate the locking dog from a first position and into a second position. The invention also relates to a method of operating the invention.

The object of the invention is, firstly, to provide a lifting hook, referred to hereinafter as "hook", which both satisfies the authorities' requirements relating to safety devices for preventing unintentional separation of hook and lifting IS implement, and at the same time satisfies a simple and reliable control of the safety device as the lifting implement is placed into the hook and as the lifting implement is separated from the hook. A second object of the invention is to provide a hook which is arranged to be so operated in a safe and simple manner by means of a remote- controlled device, such as an R.O.V. (Remote-Operated Vehicle) In this document the term lifting implement is used for components or equipment used between a lifting device and the load to be moved.

To prevent a lifting implement from being released from a s hook, it is known for the hook to be provided with a safety device formed by a locking dog which is spring-loaded into extending across the opening of the hook, the locking dog being arranged to be rotatable only towards the bottom portion of the hook.

There are several drawbacks related to the above-mentioned known hook. To free the opening of the hook in connection with separating a lifting implement from the hook, the spring-loaded locking dog must be subjected to a force exceeding the spring load. This force is normally applied manually by means of a hand of the personnel taking part in the lifting operation. This operation involves a considerable risk of, among other things, pinching injuries because the locking dog will have to be pressed inwards while, at the same time, the lifting implement is released from the hook.

In situations, in which there is a need for remote-controlled operation of the lifting operation, for example in a deep- water operation using an R.O.V., or in lifting operations in environments where humans cannot or should not be present, lifting operations using a hook according to the prior art, have turned out to be both difficult and hazardous The invention has as its object to remedy or at least reduce

one or more of the drawbacks of the prior art.

The object is achieved through features as specified in the

description below and in the following claims.

so The present invention is based on the above-mentioned known solution, but involves significant improvements relating to e a e 8 He ( a e.

the safety of personnel operating the locking dog of the hook, and also improved control when using remote-controlled manipulation of the hook.

In one aspect the present invention is formed by a hook s consisting of a hook body which terminates, in a first end portion, in a hook point and terminates, in a second end portion, in a hook shaft ending in a lifting eye. safety device in the form of a locking dog which is preferably, in a first position, spring-loaded into blocking the hook opening lo in such a way that the lifting implement cannot be uncontrolledly released from the hook, is rotatably connected at a first end portion to a portion of the hook body. The locking dog is connected to a pulling element which, on the application of an external force, is arranged to rotate the locking dog from said first position, in which the hook opening is blocked, into a second position, in which the hook opening is opened, the pulling element preferably running through a bore in the hook body.

In a preferred embodiment the pulling element is formed by a go rope of a suitable material, such as, but not restricted to, steel. In an alternative embodiment the entire pulling element or portions thereof are formed by a rod element of a suitable material, such as, but not restricted to, steel. In a further alternative embodiment the entire pulling element Is or portions thereof are formed by a chain known in itself.

The pulling element may be formed, in a further alternative embodiment, by a combination of the above-mentioned alternatives.

In a preferred embodiment the pulling element is connected to JO a portion of the locking dog facing said bore of the hook body in the second, open position of the locking dog. In this preferred embodiment the portion of the pulling element running through the portion of attachment of the pulling element on the locking dog and the bore of the hook body, :e:. A.. ...

will be protected by the locking dog against external loads from the lifting implement or manipulating tool. In addition, this preferred embodiment will practically eliminate the risk of the manipulating tool or lifting implement catching on the pulling element in connection with the insertion or release of the lifting implement into/from the hook.

In a preferred embodiment the pointed end portion of the hook is provided with at least one first notch or recess arranged to receive at least a free second end portion of the locking lo dog. The at least one first notch or recess has as its objects both to guide the free second end portion of the locking dog into correct abutment against the hook body and to prevent the locking dog from being twisted out of the hook opening by external forces after the second end portion of IS the locking dog has been brought into abutment against the hook body. The portion of the locking body which is guided into the recess of the hook body, is preferably formed essentially complementary to the surface(s), against which the locking dog is brought to rest.

ze In order to prevent a possible uncontrolled force applied to the pulling element (or directly to the locking dog) from rotating the locking dog in such a manner that the hook opening is completely or partially freed, the locking dog is arranged, in a preferred embodiment, selectively to be as blocked against rotating away from the first position, in which the locking dog closes the hook opening.

In a preferred embodiment, a portion of the hook body is provided with at least one second notch arranged to receive at least a portion of the free end portion of the locking dog So when the locking dog is rotated into the second open position. The notch(es) serve(s) at least two purposes; When the end portion of the locking dog has been moved into the notch (or notches) of the hook body, the side surfaces or wall of the notch will provide lateral support for the :e.. .. A. .. c:.

locking dog when this is subjected to resultant forces acting perpendicularly to the longitudinal direction of the locking dog. This support will reduce the risk of the locking dog being twisted out of its attachment to the hook and being damaged; By forming the notch(es) with recesses making the end portion of the locking dog, in its second open position, not extend over the internal surface of the hook body surrounding its second at least one notch, a lifting implement which is released from the hook, could not catch on lo the end portion of the locking dog. The portion of the locking dog which is moved into the notch(es) of the hook body, is preferably formed essentially complementary to the surface(s), against which the locking dog is brought to rest.

The invention also deals with a method of operating or using IS a locking dog which is arranged to block a hook opening in a hook included in a lifting device, from a first position, in which the hook opening is blocked, into a second position, in which the hook opening is open for being brought onto or releasing a lifting implement from the hook through the hook go opening, as a pulling element, preferably running through a bore in a hook body and being connected to a portion of the locking dog, is subjected to a tensional force exceeding a preloading force arranged to force the locking dog into said first position.

In what follows, there is described a non-limiting exemplary embodiment of a preferred embodiment which is visualized in the accompanying drawings, in which: Figure 1 shows a view of a hook according to the invention, in which the mouth of the hook is closed by a locking dog.

So Figure shows a perspective view of the hook of Figure 1, in which the locking dog has been rotated by means of a rope into a second position as the mouth of the hook has been opened. .

ë:. ... is; Figure 3 shows, on a larger scale, a perspective view of a portion of a hook according to the invention, viewed at an angle from behind.

In the drawings the reference numeral 1 identifies a hook s including a hook body 2, which is defined, at its one end portion, by a pointed end portion 3 and is defined, at its other end portion, by a lifting eye 7. The hook body 2 is fixed to the lifting eye 7 via a hook shaft 5 having, in the exemplary embodiment, a hexagonal cross-section. In an lO alternative embodiment (not shown), the hook body is rotatably connected to the lifting eye 7 via a rotary coupling, known in itself, between the hook shaft 5 and the lifting eye 7. The hook opening 9 is arranged selectively to be blocked by a locking dog 10 which is rotatably fixed at a first end portion 12 to a mounting portion 13 of the hook body, in a manner known in itself, by means of a bore and pin solution. The hook body 2 is provided with a through bore 20 (shown in dotted lines in Figure 1) with a first bore opening 21 at the hook opening 9 and a second bore opening 22 at a so back portion 4 of the hook body 2, through which a pulling element 25 is passed. The pulling element 25 is attached, at its one end portion, to an attachment element 16 which is fixed to a portion of the locking dog 10 facing into the hook opening 9.

as In Figure 1 the locking dog 10 is preloaded by means of a spring (not shown), known in itself, into a first position, in which the locking dog 10 blocks the hook opening 9. The second end portion 14 of the locking dog 10 extends into a first notch 30 which is divided by a notch wall 34. A portion JO of the second end portion 14 of the locking dog 10 bears on a notch limiter 35 which prevents further rotation of the locking dog 10 out of the hook opening 9.

The notch wall 34 provides a bearing surface for lifting equipment which is passed over the notch 30 when the locking :. :.. .e -I.; dog 10 is rotated at least partially towards its second position. Without the notch wall 34 some types of lifting equipment could easily get caught in the first notch 30. In addition, the notch wall 34 provides both a guiding of the locking dog 10 into a correct position relative to the hook point 3 of the hook body 2 and a support counter-acting a twisting of the locking hook 10 out of the notch 30 by external forces. Furthermore, the notch wall 34 is provided with a bore 32, through which a securing devices, such as a to pin (not shown), may easily be placed in order to ensure that the locking dog 10 cannot uncontrolledly be rotated away from the hook opening 9.

In Figures 2 and 3 the locking dog 10 has been rotated from the first, closed position shown in Figure 1 into a second, fully opened position, by the pulling element, which is formed in the exemplary embodiment by a rope 25, being subjected to a pull F which exceeds the force preloading the locking dog 10 towards said first position. In order to protect, to the greatest possible degree, the rope 25 from JO damage, the rope 25 is passed through a bore 20 in the hook body 2. This solution provides the advantageous feature of the rope 25 being shielded from influence from, among other things, a lifting implement (not shown) which is being brought into or separated from the hook 1 through the hook opening 9, In order to provide an angle of attack as flexible as possible for the pull applied to the rope 25, while at the same time the rope 25 is subjected to the least possible bearing on the wall portion of the bore 20, the bore opening 21 ending in the hook opening 9 is smaller than the bore opening 22 ending in the back portion 4 of the hook body 2.

In an alternative embodiment (not shown) the bore openings 21, 22 are formed with essentially the same size, whereas a portion of the bore 20 between said bore openings 21, 22 has a smaller size than the bore openings 21, 22.

.e. .... ....

In like manner as the first notch 30, the second notch 36 is provided with a notch wall 38 which provides guiding and lateral support for the locking dog 10. An important detail of the second notch 36 is that it is formed in such a way s that the second end portion 14 of the locking dog 10 is at least in the same plane as the internal surface 40 of the hook body 2 surrounding the notch 36, or preferably is somewhat recessed relative to this, as shown in Figure 2.

Such a design will practically eliminate the risk of the lo lifting implement (not shown) getting caught in the second notch 36 in connection with the release of the lifting implement from the hook 1.

In order to avoid the lifting implement getting caught in or damaging the mounting of the first end portion 12 of the locking dog 10 on the mounting portion 13, the hook body 2 is provided with a wedge-shaped guide portion 42 guiding the lifting implement past the first end portion 12, the mounting portion 13 into the hook opening 9.

Correspondingly, the locking dog 10 will work as a guide part so for the lifting implement out of the hook opening 9 when the locking dog 10 is in its second, open position, see figure 2.

In the figures, the hook shaft 5 is shown in a preferred embodiment with a hexagonal cross-section, which provides for simple and secure gripping by an arm of, for example, an Z5 R.O.V. The hook shaft 5 may also be formed with other cross- sectional shapes (not shown), such as, but not restricted to, triangular, oval or circular shape, or the hook shaft may be formed with a combination of two or more such cross-sectional shapes.

so The lifting eye (7) is shown in figures 1 and 2 with a cylindrical bore which is complementary to a standard dimension of the clevis pin (not shown) which is connected to the hook, so that a rigid, but rotatable, connection is c achieved. The lifting eye (7) may in alternative embodiments (not shown) be provided with other bore designs known in themselves.

The hook 1 according to the present invention provides a hook s which is well suited for remote operation, for example by means of an R.O.V., as the hook 1 is arranged both to be secured, while at the same time the locking dog 10 of the hook 1 is easily opened by the application of an external force to the pulling element 25 which preferably projects through a bore 20 through the back portion 4 of the hook body 2. The invention also provides an, as regards personnel, safe manipulation of the locking dog 10 of the hook 1 as it is manoeuvred outside the, as regards handling, most hazardous area of the hook 1.

Claims

:. .. A.. C L A I M S

1. A hook Al) arranged to be operated by means of manipulator arms connected to an R O.V., the hook (l) being included in a lifting device and the hook (1) being of the kind, in which a lifting implement is connected to and released from the hook (1) through a hook opening (9), and in which the hook opening (9) is provided with a spring-loaded looking dog (10) which is arranged to block the hook opening (9) against lo uncontrolled release of a lifting implement out through the hook opening (9), and in which the locking dog (10) is connected to a pulling element (25) extending through a bore (20) in the hook (1), the pulling element (25) being arranged to rotate the locking dog (10) from a first position, in which the hook opening (9) is blocked, into a second position, in which the hook opening (9) is open, c h a r a c t e r i z e d i n that the bore (20) is provided with bore openings (21, 22) which have a larger extent than a portion of the bore (20) located between said bore openings (21, 22), and that between the hook body (2) and a lifting eye (7), the hook (1) is provided with a hook shaft (5), which is provided, at least in one portion, with a non circular cross-section in order to prevent relative as rotation consequent on little friction between the hook shaft (5) and a gripping implement.

2. The hook (1) according to claim 1, c h a r a c t e r i z e d i n that the bore (20) of the hook (1) is provided with bore openings (21, 22) of different sizes.

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3. The hook (1) according to claim 1, c h a r a c t e r i - z e d i n that at least a portion of the hook shaft (5) is formed with at least three essentially plane surfaces encircling the hook shaft (5).

:e:. A..- . is.;

4. The hook (1) according to claim 1, c h a r a c t e r i z e d i n that at least a portion of the hook shaft (5) is formed with a cross-section of an oval shape.

5. The hook (1) according to claims 3 and 4, c h a r a c t e r i z e d i n that at least a first portion of the hook shaft (5) is provided with at least three essentially plane surfaces encircling the hook shaft (5), and that at least a second portion of the hook shaft (5) is provided with a cross-section of an oval lO shape.

6r The hook (1) according to claim 1, c h a r a c t e r i z e d i n that the pulling element (25) is formed by a rod element.

7. The hook (1) according to claim l, c h a r a c t e r i z e d i n that the pulling element (25) is formed by a chain.

8. The hook (1) according to any one of the preceding claims, c h a r a c t e r i z e d i n that the hook body (2) is provided with at least one first notch t30) zo arranged to receive at least a portion of the second end portion (14) of the locking dog tlO) when the locking dog (10) is in its closed position, and at least one second notch (36) arranged to receive at least a portion of the second end portion (14) of the locking dog (10) when the locking dog (10) is in its open position.

9, The hook (1) according to claim 8, c h a r a c t e r i - z e d i n that the at least one first notch (30) is provided with at least one notch wall (34). c e

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10. The hook (l) according to claim 8, c h a r a c t e r i z e d i n that the at least one second notch (36) is provided with at least one notch wall (38).

11. The hook (1) according to claim 8, c h a r a c t e r i s z e d i n that the at least one second notch (36) in the hook body (2) is formed with a recess which receives at least the entire second end portion (14) of the locking dog (1OJ.

12. The hook (1) according to claim 9, c h a r a c t e r i o z e d i n that the at least one notch wall (34) in the first notch (30) is provided with a bore (32) arranged to receive a locking device.

13. The hook (1) according to any one of the preceding claims, c h a r a c t e r i z e d i n that the lifting IS eye (7) of the hook (1) is rotatably connected to the hook shaft (5).