AU2006201627B2 - Lifting hook and safety attachment therefor - Google Patents

Abstract

A lifting hook with a safety attachment is provided. The lifting hook comprises a hook member, a latch pivotally 5 attached to the hook member, and a locking latch engageable with the pivotal latch in an arrangement whereby the pivotal latch is prevented from being pivoted relative to the hook member unless the locking latch is disengaged from the pivotal latch. The lifting hook further comprises a handle and a 10 trigger pivotally coupled to the handle such that the trigger is operable while grasping the handle, whereby operation of the trigger disengages the locking latch from the pivotal latch. Advantageously, the spacing to which one or two of the operator's hands will be placed to disengage the pivotal latch 15 is well removed from the proximity of the chains and slings hitched to the lifting hook itself. Kirstie/keep/speci/other/P56536 19/04/2006 69 62 4 146 3 4442 22o 67 38-.. 100-> 8 6 1 66 100 685 52 6130 69 62 52 46 22a 4:10l 38 2-6 60 jso4 28 2 32 22b

Description

P/00/) 11 Regulation 3.2 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Ronald Francis Norrish Address of Applicant: 463 Crawford Road Dianella WA 6059 Australia Name of Applicant: Ian Geoffrey Walton Address of Applicant: 24 Castlemore Mews Ballajura WA 6066 Australia Actual Inventors: Ronald Francis NORRISH Ian Geoffrey WALTON Address for Service: Griffith Hack, Patent and Trade Mark Attorneys, 19th Floor, 109 St Georges Terrace, Perth, Western Australia, 6000. Standard Complete Specification for the invention entitled: LIFTING HOOK AND SAFETY ATTACHMENT THEREFOR Details of Associated Provisional Applications: Australian Provisional Patent Application No. 2005901954 filed 19 April 2005 The following is a full description of this invention, including the best method of performing it known to me:- - 2 LIFTING HOOK AND SAFETY ATTACHMENT THEREFOR Field of the Invention 5 The present invention relates to a lifting hook, in particular to a lifting hook provided with a safety attachment. Background of the Invention 10 A lifting hook typically comprises a generally J- or U-shaped hook defining two legs spaced apart from one another so as to define an open mouth, and a latch having a free end and another end pivotally fixed to a first one of the two legs. The latch or the first one of the two legs is often provided with a loop 15 for support of the lifting hook. The free end of the latch is pivotable between an open and a closed configuration. In the closed configuration, the free end is disposed adjacent to a second one of the two legs of the U 20 shaped hook such that the latch extends across the open mouth to prevent exit of lifting chains/slings suspended on the hook. In the open configuration, the free end is spaced apart from the first and the second of the two legs of the U-shaped hook such that the open mouth of the hook can receive the lifting 25 chains/slings to be suspended on the hook. To prevent unintentional pivotal movement of the latch from the closed configuration to the open configuration, the lifting hook is provided with a locking latch which engages with the latch in 30 an arrangement whereby the latch is prevented from being pivoted to the open configuration unless the locking latch is first Kirstie/keep/sp eci/other/P5653 6 19/04/2006 - 3 disengaged from the latch. Disengagement (or engagement) of the locking latch in relation to the latch requires considerable manual effort from an 5 operator. Typically, the configuration of the locking latch in relation to the lifting hook entails that the operator must grasp the U-shaped hook with both hands in order to disengage (or engage) the locking latch from the latch, in which case the operator places his or her fingers within a cavity defined by 10 the hook and the latch, in close proximity with lifting chains/slings suspended by the lifting hook. During disengagement (or engagement) of the locking latch, it is common for the lifting chains/slings to move within the cavity, thereby catching and causing physical damage to the operator's fingers. 15 Even if the operator is not physically harmed, his or her glove can become caught and it is then difficult for the operator to extricate his or her hand from the cavity. Further, in some instances, disengagement of the locking latch 20 and removal of the lifting chains/slings from the hook is a two person operation, providing each operator with a reduced working space in which to move should the lifting hook swing from its suspended position. 25 It is to be understood that, although prior art use and publications may be referred to herein, such reference does not constitute an admission that any of these form a part of the common general knowledge in the art, in Australia or any other country. 30 Kirstie/keep/sp eci/other/P5653 6 19/04/2006 -4 2 Summary of the Invention 5 According to a first aspect of the invention there is provided a lifting hook comprising a hook member, a latch pivotally attached to the hook member at a first pivot point, a locking latch pivotally attached to the hook member at a second pivot 10 point, the locking latch being engageable with the latch in an arrangement whereby the latch is prevented from being pivoted relative to the hook member unless the locking latch is disengaged from the latch, a handle, and a trigger pivotally coupled to the handle such 15 that the trigger is operable by hand to disengage the locking latch from the latch. In one embodiment the hook member comprises two legs spaced apart from one another so as to define an open mouth. 20 In a further embodiment the latch has a free end and a fixed end pivotally mounted at a first pivot point disposed on a first of the two legs of the hook member, the latch being pivotable between a closed configuration wherein the free end is disposed 25 adjacent to a second of the two legs of the hook member such that the latch extends across the open mouth and an open configuration wherein the free end is spaced apart from the first and the second of the two legs. 30 The locking latch prevents unintentional pivotal movement of the pivotal latch from the closed configuration to the open configuration, the locking latch being engageable with the pivotal latch in an arrangement whereby the latch is prevented 272622_1 (GHMtter) P58536 AU.1 -5 from being pivoted to the open configuration unless the locking latch is first disengaged from the latch. In another embodiment the locking latch is pivotally mounted on the first of the two legs of the hook member at a second pivot point proximal to the 5 fixed end of the latch, the locking latch being provided with a pair of spaced apart opposing protrusions which define a bearing surface therebetween, the latch being provided with a notch configured to receive one of the opposing protrusions when the locking latch engages the latch. 10 In one embodiment the handle outwardly depends from the first leg of the hook member. The handle can be C-shaped or L-shaped, thereby defining a space between the handle and the first leg of the hook member. In a preferred embodiment, the handle has a U 15 shaped sectional profile. In one embodiment the trigger comprises an L-shaped member having a first arm operatively engaged with the locking latch and a second arm pivotable between a first configuration and a 20 second configuration, wherein pivotal movement of the second arm from the first configuration towards the second configuration causes the first arm to apply pressure on the bearing surface of the locking latch and the locking latch to disengage the pivotal latch in response to the applied pressure. The second arm of 25 the trigger is arranged, in use, to depress the second protrusion of the locking latch by applying downward pressure to the bearing surface thereof, thereby causing the locking latch to pivot about the second pivot point so as to disengage the first protrusion of the locking latch from the notch of the 30 pivotal latch. 272622_1 (GHMatters) P56536.AU.1 -6 In the first configuration the second arm of the trigger substantially extends into the space defined between the handle and the first leg of the hook member and in the second configuration the second arm of the trigger extends toward 5 handle and is receivable, at least in part, in the U-shaped sectional profile of the handle. In one embodiment the handle is further provided with an aperture arranged to receive a locking pin, whereby in use, the 10 trigger cannot be operated to disengage the locking latch from the latch until the locking pin is removed from the aperture. Typically the hook member is further provided with a loop end for support of the lifting hook. 15 In the preferred embodiment, the lifting hook comprises: a hook member having two legs spaced apart from one another so as to define an open mouth; a latch having a free end and a fixed end pivotally mounted 20 at a first pivot point disposed on a first of the two legs, the latch being pivotable between a closed configuration wherein the free end is disposed adjacent to a second of the two legs of the hook member such that the latch extends across the open mouth and an open configuration wherein the free end is spaced apart 25 from the first and the second of the two legs; a locking latch to prevent unintentional movement of the latch from the closed configuration to the open configuration, the locking latch being engageable with the latch in an arrangement whereby the latch is prevented from being pivoted to 30 the open configuration unless the locking latch is first disengaged from the pivotal latch, 2720220_1 (GHatt.) P56536AU 1 -7 the locking latch being pivotally mounted on the first of the two legs of the hook member at a second pivot point proximal to the fixed end of the latch, the locking latch being provided with a pair of spaced apart opposing protrusions which define a 5 bearing surface therebetween, the latch being provided with a notch configured to receive one of the opposing protrusions when the locking latch engages the latch; a handle outwardly depending from the first leg of the hook member; and 10 a trigger pivotally mounted on the handle and operable by grasping the handle, the trigger comprising an L-shaped member having a first arm operatively engaged with the locking latch and a second arm pivotable by an operator between a first configuration and a second configuration, wherein pivotal 15 movement of the second arm from the first configuration towards the second configuration causes the first arm to apply pressure on the bearing surface of the locking latch and the locking latch to disengage the latch in response to the applied pressure. 20 According to a second aspect of the invention there is provided a safety attachment adapted for use with a lifting hook wherein the lifting hook comprises a hook member, a latch pivotally attached to the hook member at a first pivot point, 25 and a locking latch pivotally attached to the hook member of a second pivot point, the locking latch being engageable with the latch in an arrangement whereby the latch is prevented from being pivoted relative to the hook member unless the locking latch is disengaged from the latch, characterized in 30 that the safety attachment comprises a handle mountable on the hook member and a trigger pivotally coupled to the handle such -8 that the trigger is operable by hand to disengage the locking latch. In the description of the invention and the claims, except 5 where the context requires otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features, but not to preclude the presence or addition of further 10 features in various embodiments of the invention. Brief Description of the Drawings A preferred embodiment, incorporating all aspects of the 15 invention, will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a side elevation view of a lifting hook in a closed configuration in accordance with the present invention; and 20 Figure 2 shows a side elevation view of the lifting hook of Figure 1 in an open configuration. Detailed Description of the Preferred Embodiments of the Invention 25 Before the preferred embodiment of the present invention is described, it is understood that this invention is not limited to the particular materials described, as these may vary. It - 9 is also to be understood that the terminology used herein is for the purpose of describing the particular embodiment only, and is not intended to limit the scope of the present invention in any way. It must be noted that as used herein, 5 the singular forms "a", "an", and "the" include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention 10 belongs. Referring to Figures 1 and 2 there is shown a lifting hook 10 including a generally U-shaped hook 20 and a pivotal latch 30 pivotable between an open configuration as shown in Figure 1 and 15 a closed configuration as shown in Figure 2. The U-shaped hook 20 comprises two legs 22a, 22b spaced apart from one another so as to define an open mouth 24. The pivotal latch 30 has a free end 32 and a fixed end 34 pivotally mounted at first pivot point 26 disposed on a first of the two legs 22a. The fixed end 34 is 20 further provided with a loop end 36 for support of the lifting hook 10. In the closed configuration, the free end 32 is disposed adjacent to a second of the two legs 22b of the U-shaped hook 20 25 such that the pivotal latch 30 extends across the open mouth 24 to prevent exit of lifting chains/slings suspended on the hook 20. In the open configuration, the free end 32 is spaced apart from the first and the second of the two legs 22a, 22b of the U shaped hook 20 such that the open mouth 24 of the hook 20 can 30 receive the lifting chains/slings to be suspended on the hook 20, or alternatively the lifting chains/slings can be removed Kirstie/keep/sp eci/other/P5653 6 19/04/2006 - 10 from the hook 20. To prevent unintentional pivotal movement of the pivotal latch 30 from the closed configuration to the open configuration, the 5 lifting hook 10 is provided with a locking latch 40 which engages the pivotal latch 30 in an arrangement whereby the pivotal latch 30 is prevented from being pivoted to the open configuration unless the locking latch 40 is first disengaged from the pivotal latch 30. 10 The locking latch 40 is pivotally mounted on the U-shaped hook 20 at second pivot point 28 adjacent to the fixed end 34 of the pivotal latch 30. The locking latch 40 is provided with a first protrusion 42 and an opposing second protrusion 44. Both 15 protrusions 42, 44 are spaced apart from the second pivot point 28 and each other, thereby defining a bearing surface 46 therebetween. The pivotal latch 30 is provided with a notch 38 configured to 20 receive the first protrusion 42 of the locking latch 40 when the locking latch 40 engages the pivotal latch 30. Generally, the locking latch 40 is biased towards engagement of the first protrusion 42 of the locking latch 40 with the notch 38 of the pivotal latch 30. 25 Typically, the locking latch 40 may be disengaged from the pivotal latch 30 by applying pressure to the bearing surface 46 of the locking latch 40 proximate to the second protrusion 44. In other words, when the second protrusion 44 is depressed by 30 applying downward pressure to the bearing surface 46, the locking latch 40 is caused to pivot about the second pivot point Kirstie/keep/speci/other/P5653 6 19/04/2006 - 11 28 so as to disengage the first protrusion 42 from the notch 38. The lifting hook 10 as described above is of a type commonly used in the construction industry, and similar versions thereof 5 are also used for towing and lifting purposes and in the fishing industry. As will be evident from the description, it is envisaged that the present invention is suitable for use for the abovementioned purposes and industries. 10 The lifting hook 10 is provided with a safety attachment 100 comprising a trigger 50 and a handle 60. Typically, the trigger 50 and the handle 60 are formed from rigid, inert materials such as moulded plastics materials, metals and alloys. The handle 60 in one embodiment of the invention has a U-shaped sectional 15 profile, in which recess of the U-shaped sectional profile the trigger 50 is received, at least in part. In an alternative embodiment, the handle 60 can be formed from two identical mirror-image sections, for example with L-shaped sectional profiles, which are clamped together to afford the handle 60 as 20 described below. The handle 60 and the trigger 50 may be readily retro-fitted onto existing lifting hooks by clamping the two identical mirror-image sections to opposing front and rear surfaces of the lifting hook 10 and to each other. 25 Referring to Figures 1 and 2, the handle 60 outwardly depends from an outer side surface of the first leg 22a of the U-shaped hook 20. In this way, the handle 60 and the first leg 22a of the U-shaped hook 20 define a space 68 therebetween adjacent to but spaced apart from the space defined by the U-shaped hook 20 30 and the pivotal latch 30 when disposed in the closed configuration, the space 68 being sufficiently large for one or Kirstie/keep/speci/other/P5653 6 19/04/2006 - 12 two hands of an operator to be inserted therein. Advantageously, the space 68 into which one or two of the operator's hand will be placed is located on an opposite side of the first leg 22a relative to the range of movement of the 5 pivotal latch 30 and the open mouth 24 of the U-shaped hook 20, being well removed, in use, from the proximity of the chains and slings hitched to the lifting hook 10. In the embodiment shown in the Figures, the handle 60 is 10 generally C-shaped comprising a first section 62 with a first end 61 mounted proximal to or substantially coincident with the second pivot point 28 of the locking latch 40, a second section 64 with a second end 63 spaced apart from the first end 61 and mounted to the first leg 22a of the U-shaped hook 20, and an 15 intermediate section 66 extending between the first and second sections 62, 64. The first section 62 is disposed at substantially right angles to the first leg 22a of the U-shaped hook 20 and the intermediate section 66 is spaced apart from and in substantially parallel alignment with the first leg 22a of 20 the U-shaped hook 20. In an alternative embodiment, the handle 60 is generally

L

shaped comprising the first and intermediate sections 62, 66 as described above. In the absence of the second section 64 which 25 typically affords structural stability, it is envisaged that the L-shaped handle 60 will be formed in a manner where its rigidity relative to the lifting hook 10 is not substantially compromised. 30 The trigger 50 is substantially L-shaped, having a first arm 52 and a second arm 54 integrally joined together at junction 53. Kirstie/keep/sp eci/other/P5653 6 19/04/2006 - 13 The trigger 50 is pivotally mounted within the recess of the U shaped sectional profile of the handle 60 at a third pivot point 69 proximate to or substantially coincident with junction 53. Typically, the third pivot point 69 is disposed substantially at 5 the junction of the first and intermediate sections 62, 66 of the handle 60. The first arm 52 of the trigger 50 extends in the general direction of the first section 62 of the handle 60, and is 10 typically disposed in the recess thereof. The length of the first arm 52 and the location of the third pivot point 69 are configured in an arrangement whereby an end 51 of the first arm 52 engages the bearing surface 46 of the locking latch 40 proximate to the second protrusion 44. 15 The second arm 54 of the trigger 50 is pivotable about the third pivot point 69, between a first configuration wherein the second arm 54 substantially extends into the space 68 defined between the handle 60 and the U-shaped hook 20 as shown in Figure 1, and 20 a second configuration wherein the second arm 54 extends in the general direction of the intermediate section 66 and is receivable, at least in part, in the U-shaped sectional profile of the handle 60 as shown in Figure 2. 25 Pivotal movement of the second arm 54 from the first configuration towards the second configuration causes the first arm 52 to apply a downward pressure on the bearing surface 46 of the locking latch 40. In response to the downward pressure applied to the bearing surface 46, the locking latch 40 is 30 caused to pivot about the second pivot point 28 so as to disengage the first protrusion 42 from the notch 38 of the Kirstie/keep/speci/other/P565 3 6 19/04/2006 - 14 pivotal latch 30. As described previously, once the locking latch 40 has been disengaged from the pivotal latch 30, the pivotal latch 30 may then be readily pivoted to the open configuration. 5 The handle 60 is provided with an aperture 67 extending through opposing side walls of the U-shaped sectional profile of the intermediate section 66 of the handle 60. The aperture 67 is arranged to receive a locking device, such as for example a 10 locking pin. The purpose of the locking device, when received in the aperture 67, is to prevent pivotal movement of the second arm 54 between the first and second configurations. In this way, unintentional disengagement of the first protrusion 42 of the locking latch 40 from the notch 38 of the pivotal latch 30 15 can be prevented. Typically, the aperture 67 is disposed in the intermediate section 66 of the handle 60 proximal to pivot point 69, so that a locking device received therein would restrict pivotal movement of the second arm 54. 20 In the embodiment shown in the Figures, the handle 60 is provided with a gusset 70 depending between the second section 64 of the handle 60 and the first leg 22a of the hook member 20. The gusset 70 is generally triangular-shaped. Aside from the structural strength it affords the handle 60, the gusset 70 25 deflects chains or ropes from becoming caught and retained between the second section 64 of the handle 60 and the first leg 22a of the hook member 20. The gusset 70 can be provided with an aperture 71 for receiving 30 a rope, chain or tender line to retrieve or assist in positioning the lifting hook 10. Kirstie/keep/sp eci/other/P56 5 3 6 19/04/2006 - 15 In use, an operator may disengage the locking latch 40 from the pivotal latch 30 by first removing the locking device from the aperture 67 in the handle 60. The operator then grasps the 5 handle 60 and second arm 54 of the trigger 50 with either one or both hands. Upon squeezing the trigger 50 toward the recess of the handle 60, the second arm 54 pivots about the third pivot point 69 between the first and second configurations causing the end 51 of the first arm 52 to apply a downward pressure to the 10 bearing surface 46 of the locking latch 40. In response to the downward pressure applied to the bearing surface 46, the locking latch 40 is caused to pivot about the second pivot point 28 so as to disengage the first protrusion 42 from the notch 38 of the pivotal latch 30. Once the locking latch 40 is disengaged, the 15 pivotal latch 30 may be pivoted about the first pivot point 26 and chains or slings may then be removed from, or engaged with, the U-shaped hook 20. Numerous variations and modifications will suggest themselves 20 to persons skilled in the relevant art, in addition to those already described, without departing from the basic inventive concepts. All such variations and modifications are to be considered within the scope of the present invention, the nature of which is to be determined from the foregoing 25 description. Kirstie/keep/speci/other/P 5 6 5 3 6 19/04/2006

Claims (16)

1. A lifting hook comprising: 5 a hook member, a latch pivotally attached to the hook member at a first pivot point, a locking latch pivotally attached to the hook member at a second pivot point, the locking latch being 10 engageable with the latch in an arrangement whereby the latch is prevented from being pivoted relative to the hook member unless the locking latch is disengaged from the latch, a handle, 15 and a trigger pivotally coupled to the handle such that the trigger is operable by hand to disengage the locking latch from the latch.

2. The lifting hook according to claim 1, wherein the 20 locking latch is provided with a pair of spaced apart opposing protrusions which define a bearing surface therebetween and the latch is provided with a notch configured to receive one of the opposing protrusions when the locking latch engages the latch. 25

3. The lifting hook according to claim 2, wherein the trigger comprises an L-shaped member having a first arm operatively engaged with the locking latch and a second arm pivotable between a first configuration and a 30 second configuration, wherein pivotal movement of the second arm from the first configuration towards the 2726001_1 (GH Matters) P56536.AU.1 3010611 -17 second configuration causes the first arm to apply pressure on the bearing surface of the locking latch and the locking latch to disengage the latch in response to the applied pressure. 5

4. The lifting hook according to claim 3, wherein the second arm of the trigger is arranged, in use, to depress the second protrusion of the locking latch by applying downward pressure to the bearing surface 10 thereof, thereby causing the locking latch to pivot about the second pivot point so as to disengage the first protrusion of the locking latch from the notch of the latch. 15

5. The lifting hook according to any one of the preceding claims, wherein the hook member comprises two legs spaced apart from one another so as to define an open mouth, and the latch is pivotable about the first pivot point between a closed configuration wherein the latch 20 extends across the open mouth and an open configuration wherein a free end of the latch is spaced apart from the two legs of the hook member.

6. The lifting hook according to claim 5, wherein the 25 handle outwardly depends from a first leg of the hook member thereby defining a space between the handle and the first leg of the hook member.

7. The lifting hook according to claim 6, wherein in the 30 first configuration the second arm of the trigger substantially extends into the space defined between 2726001_1 (GHMatters) P56536.AU.1 30/0611 -18 the handle and the first leg of the hook member and in the second configuration the second arm of the trigger extends toward the handle. 5

8. The lifting hook according to any one of the preceding claims, wherein the handle has a U-shaped sectional profile.

9. The lifting hook according to claim 8, wherein in the 10 second configuration the second arm of the trigger is receivable, at least in part, in the U-shaped sectional profile of the handle.

10. The lifting hook according to any one the preceding 15 claims, wherein the handle is C-shaped or L-shaped.

11. The lifting hook according to any one of the preceding claims, wherein the handle is further provided with an aperture arranged to receive a locking pin, whereby in 20 use, the trigger is prevented from disengaging the locking latch from the latch until the locking pin is removed from the aperture.

12. The lifting hook according to any one of the preceding 25 claims, wherein the hook member is further provided with a loop end for supporting the lifting hook.

13. The lifting hook according to any one of the preceding claims, wherein the handle is provided with a gusset 30 with an aperture therein. 2726001_1 (GHMatters) P56536.AU.1 3=0611 -19

14. A safety attachment adapted for use with a lifting hook wherein the lifting hook comprises a hook member, a latch pivotally attached to the hook member at a first pivot point, and a locking latch pivotally 5 attached to the hook member at a second pivot point, the locking latch being engageable with the latch in an arrangement whereby the latch is prevented from being pivoted relative to the hook member unless the locking latch is disengaged from the latch, 10 characterised in that the safety attachment comprises a handle mountable on the hook member and a trigger pivotally coupled to the handle such that the trigger is operable by hand to disengage the locking latch from the latch. 15

15. A lifting hook substantially as hereinbefore described with reference to the accompanying drawings.

16. A safety attachment adapted for use with a lifting 20 hook substantially as hereinbefore described with reference to the accompanying drawings. 2726001_1 (GHMatters) P56536.AU.1 3o/o611