AU2021254592A1

AU2021254592A1 - Clutch for a Lifting Assembly

Info

Publication number: AU2021254592A1
Application number: AU2021254592A
Authority: AU
Inventors: Arno Gurtler
Original assignee: Plastic Solutions Australia Pty Ltd
Current assignee: Plastic Solutions Australia Pty Ltd
Priority date: 2020-10-20
Filing date: 2021-10-20
Publication date: 2022-05-05

Abstract

A clutch 1 for selective engagement with a lifting anchor embedded in a concrete element to connect the anchor to a lifting shackle assembly, the clutch 1 comprising: a body 3 having a slot 17 for receiving a head of the lifting anchor, a bolt 13 engageable through a lifting eye in the head of the anchor for releasably locking the head to the clutch 1, said bolt 13 being movable along a passage in the body between engaged and released positions relative to the slot 17, said bolt 13 being connected to an operating arm to effect movement of the bolt 13 along the passage, a locking mechanism for selectively retaining the bolt in its engaged position, and a release mechanism operatively coupled to the locking mechanism, the release mechanism being operable to i) selectively release the locking mechanism, and ii) effect movement of the bolt 13 from the engaged position following said release of the locking mechanism. 18174831_1 (GHMatters) P114054.AU.1

Description

CLUTCH FOR A LIFTING ASSEMBLY FIELD OF THE INVENTION

[0001] The present invention relates to lifting assemblies used to lift concrete elements such as panels, beams, columns and the like via one or more lifting anchors embedded in the concrete element. More specifically the present invention relates to a lifting clutch for use with a lifting shackle assembly.

[0002] BACKGROUND TO THE INVENTION

[0003] Lifting anchors are used in the lifting and handling of concrete pre-cast elements such as panels in the construction industry. Lifting anchors typically include one or more legs which are embedded in the concrete panel to provide anchorage. A head of the lifting anchor remains exposed in a recess formed in an edge or face of the panel. The head includes some form of eyelet aperture to facilitate releasable engagement with a lifting clutch and shackle assembly associated with a crane to enable lifting of the panel.

[0004] Lifting shackle assemblies typically include a shackle plate having an eyelet at one end to receive a lifting hook associated with a crane or the like, and at an opposite end, a loop. Mounted to the loop of the shackle plate is a lifting clutch having a custom bolt which is used to releasably connect with the eyelet of the lifting anchor embedded in the concrete panel to facilitate lifting of the panel.

[0005] Clutches usually have a generally annular body with a central aperture through which passes the loop of the shackle plate. The annular body of the clutch has a channel-like passage within which is located an arcuate bolt that is moveable to selectively engage with the eyelet in a head of a lifting anchor. In this regard, the head of the lifting anchor is receivable in a radial aperture provided at the bottom of the annular body. The arcuate bolt is moveable

18174831_1 (GHMatters) P114054.AU.1 between a disengaged position in which the bolt is clear of the radial aperture, and an engaged position in which the bolt projects across the radial aperture and through the eyelet of the lifting anchor positioned in the radial aperture to thereby secure the lifting anchor to the lifting shackle assembly.

[0006] In order to activate the bolt, an operating arm or handle integrally formed or operatively connected with the bolt, projects radially outwardly from the clutch body. The operating arm is typically hand manoeuvred to engage the clutch bolt with an anchor head and remotely operated by a ground release rope connected to the handle to disengage from the anchor head. The rope may pass directly to the ground or in some instances the rope may pass over a pulley associated with an overhead crane or typically through a chain link. In order to release the bolt from an engaged position in which it projects through the radial aperture, the operating arm is upwardly rotated approximately 900 degrees to a generally vertical position.

[0007] A problem with clutches of the above described type is that they rely solely on the weight of the operating arm and weight of the concrete element on the bolt during a lift to maintain the bolt in the engaged position. There is no fail safe mechanism to prevent the bolt from being dislodged from the engaged position inadvertently.

[0008] It would be desirable to provide a clutch of the above described general type which has one or more improved features.

[0009] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material formed part of the prior art base or the common general knowledge in the relevant art on or before the priority date of the claims herein.

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SUMMARY OF THE INVENTION

[0010] In accordance with a first aspect of the invention, there is provided a clutch for selective engagement with a lifting anchor embedded in a concrete element to connect the anchor to a lifting shackle assembly, the clutch comprising: a body having a slot for receiving a head of the lifting anchor, a bolt engageable through a lifting eye in the head of the anchor for releasably locking the head to the clutch, said bolt being movable along a passage in the body between engaged and released positions relative to the slot, said bolt being connected to an operating arm to effect movement of the bolt along the passage, a locking mechanism for selectively retaining the bolt in its engaged position, the locking mechanism including a latch member mounted to or forming part of the operating arm and adapted to cooperate with the clutch body to releasably lock the bolt against release from its engaged position, and a release mechanism operatively coupled to the locking mechanism, the release mechanism being operable to i) selectively release the latch member from retained engagement with the clutch body, and ii) effect movement of the bolt from the engaged position following said release of the latch member.

[0011] The release mechanism is preferably coupled to the latch member and is operable to effect movement of the bolt from its engaged position to its released position once the latch member is retracted from retained engagement with the clutch body.

[0012] The release mechanism preferably includes a release line attached to the latch member. The release line enables remote operation of the locking mechanism, for example from the ground.

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[0013] In a preferred form, the bolt and passage in the clutch body are of arcuate form and the operating handle extends generally radially relative to the bolt. Preferably, the latch member is pre-load biased, for example by a spring, to an extended position to effect locking of the bolt relative to the clutch body and is retractable against the spring bias to permit release movement of the bolt by application of a pulling force to the release line.

[0014] Preferably, the clutch body includes one or more protruding lugs, the latch member in its extended position preventing release of the bolt by engagement of the latch member behind the one or more lugs. It is also particularly advantageous that the one or more protruding lugs each include a ramp portion, the latch member being able to ride up the ramp portion and over the lug when the bolt is moved from the released position to the engaged position.

[0015] Particularly advantageously, the locking mechanism includes a housing which is mounted to or forms part of the operating arm, the latch member being mounted for linear movement within the housing. Preferably, the latch member includes an elongate aperture, the latch member being retained within the housing and restricted to linear movement by a pin positioned through the elongate aperture. In one embodiment, the housing includes a pair of opposing side walls between which the latch member is located, each side wall having a mounting aperture therein within which opposed ends of the pin are positioned. The latch member may be biased to the extended position by a pre-load mechanism, for example a spring, mounted between the latch member and an end wall of the housing.

[0016] In one form, the latch member includes an anchor point for securing the release line to the latch member, the anchor point being formed in a tab projecting outwardly from a main body of the latch member. The anchor point is advantageously provided by a hole in the tab, the release line passing through the hole and being prevented from removal therewith by an end region of the

18174831_1 (GHMatters) P114054.AU.1 release line being larger in size than the hole. For example, the end region of the release line may include a knot tied in the end or alternatively a bulbous end formation may be provided at the end of the release line.

[0017] In one embodiment, the housing of the lock mechanism further includes a guide member at one end of the housing for supporting and changing the path of the release line. The release line spanning between the guide member and the anchor point preferably lies generally parallel to the main body of the latch member.

[0018] In another aspect of the invention, there is provided a clutch for selective engagement with a lifting anchor embedded in a concrete element to connect the anchor to a lifting shackle assembly, the clutch comprising: a body having a slot for receiving a head of the lifting anchor, a bolt engageable through a lifting eye in the head of the anchor for releasably locking the head to the clutch, said bolt being movable along a passage in the body between engaged and released positions relative to the slot, said bolt being connected to an operating arm to effect movement of the bolt along the passage, a locking mechanism for selectively retaining the bolt in its engaged position, and a release mechanism operatively coupled to the locking mechanism, the release mechanism being configured to i) selectively release the locking mechanism and ii) effect movement of the bolt from the engaged position following release of the locking mechanism.

[0019] To assist in further understanding the invention, reference will now be made to the accompanying drawings which illustrate preferred embodiments. It is to be appreciated that these embodiments are given by way of illustration only and that the invention is not be limited by these illustrations.

BRIEF DESCRIPTION OF THE DRAWINGS

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[0020] Figure 1 is a perspective view of a ring clutch in accordance with an embodiment of the invention, the ring clutch being shown attached to a shackle plate and the bolt of the clutch being shown in its engaged position extending through the anchor head receiving slot in the clutch body;

[0021] Figure 2 is an exploded view of the components of the ring clutch (excluding the release line) illustrated in Figure 1;

[0022] Figure 3 is a side view of the ring clutch illustrated in Figure 1 (excluding the shackle plate) illustrating the clutch bolt in its engaged position and the latch member of the locking mechanism in its extended position preventing release of the bolt by engagement of the latch member behind the lugs of the clutch body;

[0023] Figure 4 is a side view similar to Figure 3 illustrating the latch member of the locking mechanism in a retracted position thereby enabling the clutch bolt to be moved from its engaged position;

[0024] Figure 5 is a partial side view of the clutch illustrated in Figure 1 showing the latch member of the locking mechanism in a released position with an end of the latch member in abutment with a ramp portion of the protruding lugs; and

[0025] Figure 6 is a detailed view of the operating arm of the clutch showing the latch member partially cut away to illustrate the inner workings of the lock mechanism.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0026] With reference to the accompanying drawings there is shown a ring clutch 1 for selective engagement with a lifting anchor (not illustrated). The ring

18174831_1 (GHMatters) P114054.AU.1 clutch 1 includes an annular body 3 having a central aperture 5 through which a loop 7 of a shackle plate 9 is positioned. The annular body 3 further includes an arcuate passage in the form of an annular channel 11 within which is mounted an arcuate bolt 13 that is integrally formed or connected to a radial operating arm 15. The annular channel 11 has an open section at an upper part of the annular body 3 such that during assembly the arcuate bolt 13 can be inserted into the channel 11 before being rotated downwards, in a clockwise direction when viewed as in Figure 1, into the lower part of the annular body 3. The annular body 3 further includes a radial aperture/slot 17 within which the head of a lifting anchor (not shown) is positionable such that the bolt 13 can pass through an eyelet in the anchor head to fasten the anchor to the clutch 1. Figures 1, 3 and 4 illustrate the bolt 13 in an engaged position in which the bolt 13 traverses the radial aperture 17 and passes through the eyelet in a lifting anchor (not shown) when positioned within the aperture 17.

[0027] The clutch 1 further includes a locking mechanism for selectively retaining the bolt 13 in its engaged position. The locking mechanism includes a retractable latch member 19 mounted to or forming part of the operating arm 15. The latch member 19 is adapted to cooperate with the clutch body 3 to releasably lock the bolt 13 against release from its engaged position. In this regard, the clutch body 3 includes one or more protruding lugs 21 which project radially outwardly. Preferably a pair of protruding lugs 21 is provided with the lugs 21 being to either side of the open section of the annular channel 11. The latch member 19 includes a main body 23 which has at least one tongue 25 at one end which engages with one of the corresponding protruding lugs 21 on the annular body 3 to selectively lock the bolt 13 against release from its engaged position. Preferably a pair of tongues 25 is provided which are spaced apart a suitable distance to align with the spacing of the protruding lugs 21 at either side of the annular channel 11. When the latch member 19 is in its extended position illustrated in Figure 3, the pair of tongues 25 are positioned below or in abutment with an underside wall 24 of the protruding lugs 21 thereby preventing

18174831_1 (GHMatters) P114054.AU.1 anticlockwise movement (when viewed as in Figure 3) of the operating arm 15 and associated bolt 13 relative to the annular body 3.

[0028] The locking mechanism further includes a housing 27 which is mounted to or forms part of the operating arm 15. The retractable latch member 19 is preferably mounted partially within an open cavity formed within the housing 27 which is defined by a pair of opposing side walls 29 of the housing 27. The latch member 19 is mounted within the cavity and is restricted to linear movement by a retaining pin 31 which passes through an elongated aperture 33 provided in the main body 23 of the latch member 19. Opposing ends of the retaining pin 31 are supported in a mounting aperture 35 provided in each side wall 29 of the housing 27.

[0029] The retractable latch member 19 is subjected to an inwardly directed resilient bias relative to the annular body 3 by a spring member which engages with an end wall in the cavity of the housing 27 and abuts at an opposite end with an underside step 39 in the latch member main body 23. In the embodiments illustrated, the spring member is in the form of a compression spring 37. It is however to be understood that other forms of biasing spring arrangement could be incorporated. The compression spring 37 is prevented from lateral movement by a pair of blocks 40 which project inwards towards the spring 37 from the opposing side walls 29 within the cavity.

[0030] The clutch 1 further includes a release mechanism operatively coupled to the locking mechanism. The release mechanism includes a release line 41 which is preferably coupled to the latch member 19 to facilitate remote operation of the locking mechanism. The release line 41 is preferably in the form of a chord, rope or cable which is anchored to the latch member 19. In this regard, the latch member 19 preferably includes an anchor point for securing the release line 41. The anchor point is preferably formed in a tab 43 which projects generally upright, perpendicular to the main body 23 of the latch member 19. The anchor point in one embodiment is provided by a hole 45 in the tab 43 through

18174831_1 (GHMatters) P114054.AU.1 which the release line 41 is positioned and prevented from removal by an end region of the release line 41 being larger in size than the hole 45. For example, the end region of the release line 41 may include an end knob or a knot tied in the end of the release line 41 which prevents separation of the release line 41 from the tab 43. It is however to be understood that other forms of fastening arrangements could be incorporated.

[0031] The housing 27 may further include a guide member at one end of the housing 19 for guiding and altering the path of the release line 41. In one particular embodiment, the guide member is in the form of an upstanding arm 47 having an opening therein through which the release line 41 passes. The opening has curved edges to avoid the release line 41 becoming snagged on the upstanding arm 27.

[0032] In order to move the clutch bolt 13 from its locked position shown in Figure 3, the latch member 19 must first be retracted against the spring bias until the tongues 25 are clear of the protruding lugs 21 of the clutch body 3. This requires a deliberate release action by pulling of the release line 41. Once the latch member 19 is clear of the lugs 21 as shown in Figure 4, further pulling of the release line 41 results (when viewed as shown in Figure 4) in anticlockwise movement of the operating arm 15 with the clutch bolt 13 being displaced from the engaged position. Once the clutch bolt 13 has been retracted a sufficient distance to be clear of the radial slot 17 in the clutch body 3, the lifting anchor is free to be inserted or removed from the slot 17.

[0033] To attach a lifting anchor to the clutch 1, the head of the lifting anchor is firstly inserted into the radial slot 17 and positioned such that the eyelet in the head of the anchor aligns with the annular channel 11. The operating arm 15 is then moved downwardly in a clockwise direction resulting in movement of the bolt 13 in the same direction. The operation arm 15 generally provides sufficient weight to enable it to move downwardly without any external input, although hand guidance is applied to the clutch body 3 and operating arm 15 to ensure that the

18174831_1 (GHMatters) P114054.AU.1 bolt 13 moves appropriately into correct engagement with the receiving anchor eyelet. As the operating arm 15 is moved downwardly, the tongues 25 slide along ramped portions 26 of the lugs 21, as illustrated in Figure 5, which retracts the latch member 19 into the housing 27. With continued downwards motion the tongues 26 ride up and over the lugs 21 to the self-locking position illustrated in Figure 3 where the tongues 25 locate underneath the lugs 21 with the latch member 33 fully extended. In this position the clutch bolt 13 is located through the eyelet of the anchor and is retained in an extended locked position.

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Claims

CLAIMS:

1. A clutch for selective engagement with a lifting anchor embedded in a concrete element to connect the anchor to a lifting shackle assembly, the clutch comprising: a body having a slot for receiving a head of the lifting anchor, a bolt engageable through a lifting eye in the head of the anchor for releasably locking the head to the clutch, said bolt being movable along a passage in the body between engaged and released positions relative to the slot, said bolt being connected to an operating arm to effect movement of the bolt along the passage, a locking mechanism for selectively retaining the bolt in its engaged position, the locking mechanism including a latch member mounted to or forming part of the operating arm and adapted to cooperate with the clutch body to releasably lock the bolt against release from its engaged position, and a release mechanism operatively coupled to the locking mechanism, the release mechanism being operable to i) selectively release the latch member from retained engagement with the clutch body, and ii) effect movement of the bolt from the engaged position following said release of the latch member.

2. A clutch as claimed in claim 1 wherein the release mechanism is coupled to the latch member and is operable to effect movement of the bolt from its engaged position to its released position once the latch member is retracted from retained engagement with the clutch body.

3. A clutch as claimed in either claim 1 or claim 2 wherein the release mechanism includes a release line attached to the latch member, the release line enabling remote operation of the locking mechanism.

4. A clutch as claimed in any one of the preceding claims wherein the bolt and passage in the clutch body are of arcuate form and the operating handle extends generally radially relative to the bolt.

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5. A clutch as claimed claim 4 wherein the latch member is biased to an extended position to effect locking of the bolt relative to the clutch body and is retractable against the bias to permit release movement of the bolt by application of a pulling force to the release line.

6. A clutch as claimed in claim 5 wherein the clutch body includes one or more protruding lugs, the latch member in its extended position preventing release of the bolt by engagement of the latch member behind the one or more lugs.

7. A clutch as claimed in claim 6 wherein the one or more protruding lugs each include a ramp portion, the latch member being able to ride up the ramp portion and over the lug when the bolt is moved from the released position to the engaged position.

8. A clutch as claimed in any one of the preceding claims wherein the locking mechanism includes a housing which is mounted to or forms part of the operating arm, the latch member being mounted for linear movement within the housing.

9. A clutch as claimed in claim 8 wherein the latch member includes an elongate aperture, the latch member being retained within the housing and restricted to linear movement by a pin positioned though the elongate aperture.

10. A clutch as claimed in claim 9 wherein the housing includes a pair of opposing side walls between which the latch member is located, each side wall having a mounting aperture therein within which opposing ends of the pin are positioned.

11. A clutch as claimed in claim 10 wherein the latch member is biased to the extended position by a spring mounted between the latch member and an end wall of the housing.

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12. A clutch as claimed in any one of claims 3-11 wherein the latch member further includes an anchor point for securing the release line to the latch member, the anchor point being formed in a tab projecting outwardly from a main body of the latch member.

13. A clutch as claimed in claim 12 wherein the anchor point is provided by a hole in the tab, the release line passing through the hole and being prevented from removal therewith by an end region of the release line being larger in size than the hole.

14. A clutch as claimed in any one of claim 8-13 wherein the housing of the lock mechanism further includes a guide member at one end of the housing for supporting and changing direction of the release line, wherein the release line between the guide member and the anchor point lies generally parallel to the main body of the latch member.

15. A clutch for selective engagement with a lifting anchor embedded in a concrete element to connect the anchor to a lifting shackle assembly, the clutch comprising: a body having a slot for receiving a head of the lifting anchor, a bolt engageable through a lifting eye in the head of the anchor for releasably locking the head to the clutch, said bolt being movable along a passage in the body between engaged and released positions relative to the slot, said bolt being connected to an operating arm to effect movement of the bolt along the passage, a locking mechanism for selectively retaining the bolt in its engaged position, and a release mechanism operatively coupled to the locking mechanism, the release mechanism being configured to i) selectively release the locking mechanism and ii) effect movement of the bolt from the engaged position following release of the locking mechanism.

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