AU7249700A

AU7249700A - A locking mechanism

Info

Publication number: AU7249700A
Application number: AU72497/00A
Authority: AU
Inventors: Leslie Herbert Fryer; Darren Craig Muir
Original assignee: Bradken Resources Pty Ltd
Current assignee: Bradken Resources Pty Ltd
Priority date: 2000-01-14
Filing date: 2000-12-22
Publication date: 2001-07-19
Anticipated expiration: 2020-12-22
Also published as: AU767142B2

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): THE ANI CORPORATION LIMITED A.C.N. 000 421 358 Invention Title: A LOCKING MECHANISM The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 A LOCKING MECHANISM FIELD OF THE INVENTION The present invention relates generally to a locking mechanism for a rigging pin which is retractably received in an aperture of a rigging component -such as shackles, sockets and equalisers in large dragline rigging equipment.

BACKGROUND TO THE INVENTION The applicant's Australian complete patent application No.

74059/98 discloses a locking device for releasably securing a pin in a shackle of a dragline bucket. The locking device is relatively complicated in construction including a strip-like body portion, a drive screw, a sliding nut portion and a diamond-shaped locking element.

The drive screw is rotatably mounted to the body portion and threadingly engages the sliding nut portion. The locking element includes an enlarged slot through which 20 the shank of the drive screw passes. The locking element c. is positioned intermediate the body portion and the nut *see portion which are together configured so that rotation of the drive screw effects lateral displacement of the locking element relative to the body portion. The locking device is inserted in an opening in the shackle which aligns with an annular groove in the pin to prevent retraction of the pin from the shackle. The locking device is retained in the shackle by the lateral e displacement of the locking element into locking e 30 engagement with a corresponding recess in the opening of the shackle. The locking device is disengaged from the shackle and pin by counter rotation of the drive screw to release the locking element from the recess, and 40725.DOC 3 thereafter retraction of the locking device from the shackle to permit withdrawal of the pin.

SUMMARY OF THE INVENTION According to one aspect of the present invention there is provided a locking mechanism for a rigging pin which is retractably received in an aperture of a rigging component, said locking mechanism comprising: a locking bar being adapted to be retractably received in an opening in the rigging component so as to releasably engage a recess in the rigging pin wherein axial movement of the said pin is prevented; and a retaining element being configured to releasably engage the rigging component and the locking bar to prevent longitudinal movement of said bar, the retaining element being resiliently deformable wherein deformation of said element effects disengagement of the retaining element with the rigging component or the locking bar oo whereupon the locking bar can be retracted from the recess 20 of the rigging pin which can be retracted from the aperture of the rigging component.

Generally the retaining element includes an elongate retaining plug having opposing longitudinal edge portions e* adapted to releasably engage respective slots in the rigging component and the locking bar. The recess is usually an annular recess formed in the rigging pin.

Preferably the elongate retaining plug includes a 30 resiliently flexible polymeric body formed about a rigid steel insert. More preferably the polymeric body is formed from a composite polyester/polyurethane material.

40725.DOC 4 Typically the locking bar is tapered at at least one end with the slot formed adjacent said tapered end and transverse to an axis of said bar whereby said taper promotes deformation of the retaining plug whilst the locking bar is inserted into the opening of the rigging component until the retaining plug aligns with and expands into the slot of the locking bar. More typically said tapered end includes a cavity having a longitudinally oriented ramped surface, the cavity being adapted to receive a removal tool which upon insertion is configured to engage the ramped surface and the retaining plug to deform said plug wherein it is disengaged from the locking bar to permit its retraction from the opening of the rigging component.

Generally the opening in the rigging component is an elongate throughgoing opening. Typically the locking bar is tapered at both ends wherein insertion of said bar can be effected from either end of said throughgoing opening.

20 More typically the slot formed in the rigging component is one of a pair of slots.

According to another aspect of the present invention there ooo is provided a locking mechanism for a rigging pin being retractably received in an aperture of a rigging component, said locking mechanism comprising: a locking bar being adapted to be retractably received in an opening in the rigging component so as to S. releasably engage a recess in the rigging pin wherein 30 axial movement of the said pin is prevented; and a retaining pin being adapted to movably couple to either the rigging pin or the rigging component and releasably engage the locking bar to prevent longitudinal 40725.DOC movement of said bar wherein the rigging pin is locked within the aperture of the rigging component.

Preferably the retaining pin is in the form of a retaining screw which threadingly engages the rigging pin or the rigging component wherein an adjacent shanked portion of the retaining screw locates within another recess in the locking bar thereby preventing its retraction from the opening of the rigging component. More preferably the other recess is formed as a transverse groove or hole in the locking bar.

Typically the retaining screw is oriented parallel to an axis of the rigging pin and threadingly engages either a wall of the rigging pin defined between the recess and an adjacent end of the pin or the rigging component. More typically an end of the retaining screw is located within a blind hole formed in either an inner face of the other *.recess of the rigging pin and aligned with the threaded 20 wall or the rigging component, the blind hole providing additional support to the retaining screw when loaded transversely via the locking bar. Generally the blind hole is threaded.

Generally the rigging component is a shackle, socket or equaliser such as that used in a dragline bucket.

However, it should be appreciated that the invention equally extends to other applications involving the "30 releasable locking of a rigging pin to a rigging component.

40725.DOC 6 BRIEF DESCRIPTION OF THE DRAWINGS In order to achieve a better understanding of the nature of the present invention several preferred embodiments of a locking mechanism for a rigging pin will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view in part cross section of a locking mechanism inserted across an aperture of a rigging component together with a removal tool; Figure 2 is an exploded perspective view of the locking mechanism of Figure 1 together with part of a rigging pin; Figure 3 shows elevational views in part crosssection of another locking mechanism for a rigging pin of a rigging component; Figure 4 depicts plan and elevational views of the various components of the locking mechanism of Figure 3; Figure 5 is a perspective view in part cross-section of a further locking mechanism for a rigging pin of a 20 rigging component; Figure 6 is an elevational view of the locking mechanism of Figure 5; and Figure 7 is elevational views one being in part crosse section of a further locking mechanism for a rigging pin of a rigging component.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in Figures 1 and 2 there is a locking mechanism shown generally as 10 for a rigging pin 12 which is 30 retractably received in an aperture 14 of a rigging component 16. In this embodiment the rigging pin and rigging component are in the form of a shackle pin 12 and shackle 16, respectively.

40725.DOC 7 The locking mechanism 10 comprises a locking bar 18 and a retaining element 20 which in this example is in the form of an elongate retaining plug. The locking bar 18 is retractably received in an opening 22 formed in the shackle 16. The retaining plug 20 is configured to releasably engage slots 24 and 26 formed in the shackle 16 and the locking bar 18, respectively.

The locking bar 18 is in cross section generally I-shaped having a web 28 and opposing flanges 30 and 32. The upper flange 30 includes the slot 26 adjacent one end with opposing ends of the locking bar 18 including a taper formed in the upper flange 30. The web 28 of the locking bar 18 also includes a pair of longitudinally spaced apart and elliptical-shaped cut outs such as 34. A cavity 36 is formed in the end of the locking bar 18 adjacent the slot 26. The cavity 36 is in the form of a channel having a longitudinally oriented ramped surface 38. Thus, as shown 20 in Figure 1, the channel-shaped cavity 36 is designed to S. receive a removable tool 40 which upon insertion is configured to engage the ramped surface 38. The removal tool 40 includes a wedge-shaped tang 42 that is designed to locate between the ramped surface 38 and the retaining plug 20 so as to deform the plug 20 and thus effect its disengagement from the locking bar 18.

e•.

The shackle pin 12 of this embodiment is in cross-section shaped circular and is a clearance fit within the aperture S 30 14 of the shackle 16. The opening 22 is throughgoing and oriented generally perpendicular to an axis of the shackle pin 12. The throughgoing opening 22 intersects an upper portion of the aperture 14 and importantly aligns with an 40725.DOC 8 annular recess 44 formed in the shackle pin 12. The throughgoing opening 22 is elongate and shaped generally rectangular in cross-section so as to retractably receive the locking bar 18. The locking bar 18 is thus slidably received within the annular recess 44 of the shackle pin 12 so as to prevent axial movement of -the pin 12.

The retaining lug 24 of this embodiment includes a resiliently flexible polymeric body 46 formed about a steel insert 48. The retaining plug 20 also includes a void which allows deformation or compression of the retaining plug 20 to effect its disengagement from the locking bar 18. The polymeric body is formed from a composite polyester/polyurethane material with specific mechanical properties suited to this application. It is also understood that the polyester/polyurethane material bonds to the steel insert 48.

The corresponding slots 24 and 26 formed in the shackle 16 and the locking bar 18, respectively, are similar in cross-sectional shape and shaped complementary to opposing edge portions of the retaining lug 20. The void 50 is designed to locate within the shackle 16 whereas the steel insert 48 locates within the slot 26 of the locking bar 18.

In operation, one of the tapered ends of the locking bar 18 deforms or compresses the retaining plug 20 when the locking bar 18 is driven into the throughgoing opening 22 S" 30 of the shackle 16. The retaining plug 20 then expands into the slot 26 of the locking bar 18 to positively lock both the locking bar 18 and the shackle pin 12 in position. Removal of the locking bar 18 is then effected 40725.DOC 9 with the removal tool 40 wherein the retaining plug 20 is compressed into the slot 24 of the shackle 16 and is disengaged from the slot 26 of the locking bar 18. The locking bar 18 can then be driven clear of the throughgoing opening 22 and the shackle pin 12 can be retracted from the aperture 14 of the shackle 16.

Advantageously, the shackle 16 of this embodiment includes a pair of the slots 24 whereby the locking bar 18 can be inserted from either end of the throughgoing hole 22.

Figures 3 and 4 illustrate another embodiment of a locking mechanism for a rigging pin. In this other embodiment the locking mechanism 100 is installed on the shackle pin 12 of the shackle 16 of the preceding embodiment.

The locking mechanism 100 comprises a locking bar 180 which is designed to be retractably received in a throughgoing opening 220 formed in the shackle 16 so as to releasably engage an annular recess 440 formed in the shackle pin 12. The locking mechanism 100 also comprises a retaining pin which in this example is in the form of a retaining screw 101 which threadingly engages an end of the shackle pin 12 adjacent the annular recess 440 and locates within another recess 103 formed in the locking bar 180. The retaining screw is oriented parallel to an axis of the shackle pin 12 and generally perpendicular to the annular recess 440. An end of the retaining screw 101 opposite its head locates within a blind hole 105 formed 0 in the annular recess 440 of the shackle pin 12.

Preferably, the shanked portion of the retaining screw 101, which locates across the annular recess 440 and within the blind hole 105 is threaded. It will be appreciated that the blind hole 105, provides additional 40725.DOC 10 support to the retaining screw 101 when it is loaded transversely via the locking bar 180. The retaining screw 101 contains a nylon insert for fastening and is coated in a molydenum disulphate coating to prevent corrosion in service.

In operation the locking bar 180 is retained across the annular recess 440 of the shackle pin 12 via the retaining screw 101. Thus, the shackle pin 12 is prevented from being axially retracted from the shackle 16. Removal of the retaining screw 101 allows the locking bar 180 to be retracted from the shackle 16 and permits retraction of the shackle pin 12 from the shackle 16. It should be appreciated that this embodiment of the invention can conveniently be retrofitted to a conventional locking bar.

In this instance the shackle or other rigging pin is machined to permit fitting of the retaining screw 101.

The locking bar 180 may also require machining in the form ooo t of the other recess or groove 103 of the locking bar 180.

S oooo Figures 5 and 6 depict a further embodiment of a locking mechanism 1000 which includes a combination of the locking bar 18 and the retaining screw 101 of the preceding embodiments. In order to avoid repetition and for ease of reference, like components have been designated with the same reference numerals. The locking bar 18 includes the groove 103 formed in its lower edge. Otherwise, this locking mechanism 1000 functions in a similar manner to the previous example.

As shown in Figure 7 there is yet another embodiment of a locking mechanism 111 which includes a combination of the locking bar 18 and the retaining screw 101 of the 40725.DOC 11 preceding embodiments together with another retaining screw 113. In order to avoid repetition and for ease of reference, like components have been designated with the same reference numerals. The other retaining screw 113 is in this embodiment one of a pair of said screws 113 which are each in the form of grub screws which are threaded through the shackle 16 or other rigging component itself and engages an aligned opening formed in the locking bar 18. The other retaining or grub screw 113 preferably terminates in a blind hole formed in the shackle 18 adjacent the throughgoing opening 220. Otherwise, the locking mechanism 111 is similar in construction to that of the previous embodiments.

Now that several embodiments of the invention have been described in some detail it will be apparent to those skilled in the art that the locking mechanism for a rigging pin has at least the following advantages: the locking mechanism is relatively simple in 20 construction with a reduced number of components; e the locking mechanism is particularly suited to rigging components where, for example, access from one side of the rigging component may be preferred; and (iii) the locking mechanism in one form is retrofittable to existing installations.

eo.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations S" 30 and modifications other than those specifically described.

For example, the locking mechanism may extend to other applications where a rigging pin is to be releasably fitted to a rigging component. The locking bar may vary 40725.DOC 12 in its specific construction depending on the opening formed in the rigging component. The retaining pin may slidably fit rather than threadingly engage the rigging pin and be retained via another component.

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 description.

*o 40725.DOC

Claims

1. A locking mechanism for a rigging pin which is retractably received in an aperture of a rigging component, said locking mechanism comprising: a locking bar being adapted to be retractably received in an opening in the rigging component so as to releasably engage a recess in the rigging pin wherein axial movement of the said pin is prevented; and a retaining element being configured to releasably engage the rigging component and the locking bar to prevent longitudinal movement of said bar, the retaining element being resiliently deformable wherein deformation of said element effects disengagement of the retaining element with the rigging component or the locking bar whereupon the locking bar can be retracted from the recess of the rigging pin which can be retracted from the aperture of the rigging component. o •g 20

2. A locking mechanism as defined in claim 1 wherein the **ee retaining element includes an elongate retaining plug having opposing longitudinal edge portions adapted to releasably engage respective slots in the rigging component and the locking bar. ego• S.o.

3. A locking mechanism as defined in claim 2 wherein the recess is an annular recess formed in the rigging pin. S

4. A locking mechanism as defined in any one of the S" 30 preceding claims wherein the elongate retaining plug includes a resiliently flexible polymeric body formed about a rigid steel insert.

40725.DOC 14 A locking mechanism as defined in claim 4 wherein the polymeric body is formed from a composite polyester/polyurethane material. 6. A locking mechanism as defined in claim 2 wherein the locking bar is tapered at at least one end with the slot formed adjacent said tapered end and transverse to an axis of said bar whereby said taper promotes deformation of the retaining plug whilst the locking bar is inserted into the opening of the rigging component until the retaining plug aligns with and expands into the slot of the locking bar. 7. A locking mechanism as defined in claim 6 wherein said tapered end includes a cavity having a longitudinally oriented ramped surface, the cavity being adapted to receive a removal tool which upon insertion is configured to engage the ramped surface and the retaining plug to deform said plug wherein it is disengaged from the locking O. bar to permit its retraction from the opening of the 20 rigging component. e 8. A locking mechanism as defined in any one of the preceding claims wherein the opening in the rigging component is an elongate throughgoing opening. 9. A locking mechanism as defined in claim 8 wherein the locking bar is tapered at both ends wherein insertion of said bar can be effected from either end of said .throughgoing opening. A locking mechanism as defined in claim 2 wherein the slot formed in the rigging component is one of a pair of slots. 40725.DOC 15 11. A locking mechanism for a rigging pin being retractably received in an aperture of a rigging component, said locking mechanism comprising: a locking bar being adapted to be retractably received in an opening in the rigging component so as to releasably engage a recess in the rigging pin wherein axial movement of the said pin is prevented; and a retaining pin being adapted to movably couple to either the rigging pin or the rigging component and releasably engage the locking bar to prevent longitudinal movement of said bar wherein the rigging pin is locked within the aperture of the rigging component. 12. A locking mechanism as defined in claim 11 wherein the retaining pin is in the form of a retaining screw which threadingly engages the rigging pin or the rigging component wherein an adjacent shanked portion of the retaining screw locates within another recess in the 20 locking bar thereby preventing its retraction from the 0**0 opening of the rigging component. 13. A locking mechanism as defined in claim 12 wherein 0*00 o the other recess is formed as a transverse groove or hole in the locking bar. S o 14. A locking mechanism as defined in claim 12 or 13 wherein the retaining screw is oriented parallel to an Sc- axis of the rigging pin and threadingly engages either a 30 wall of the rigging pin defined between the recess and an adjacent end of the pin or the rigging component. 40725.DOC 16 A locking mechanism as defined in claim 14 wherein an end of the retaining screw is located within a blind hole formed in either an inner face of the other recess of the rigging pin and aligned with the threaded wall or the rigging component, the blind hole providing additional support to the retaining screw when loaded transversely via the locking bar. 16. A locking mechanism as defined in claim 15 wherein the blind hole is threaded. Dated this 22nd day of December 2000 THE ANI CORPORATION LIMITED By their Patent Attorneys GRIFFITH HACK OS* OS S 0 o oo O 0* 40725.DOC