WO2008025062A1

WO2008025062A1 - Locking pin and a locking pin arrangement

Info

Publication number: WO2008025062A1
Application number: PCT/AU2007/001231
Authority: WO
Inventors: David Dingwall
Original assignee: Cutting Edges Replacement Parts Pty Ltd
Priority date: 2006-08-28
Filing date: 2007-08-27
Publication date: 2008-03-06

Abstract

A two-part locking pin for a mining bucket tooth retaining attachment includes a rotating part (300) having a hexagonal nut (306) and a threaded shaft (304) adapted to connect to an insertion part (200) having a keyway (202) and a seat groove (204). The locking pin is inserted in a through hole which is adjacent to a communicating engagement member hole, the engagement member having teeth (404, 406) which project into the locking member hole, so the locking member can only be inserted when the keyway is aligned with the projecting teeth. Slots on the locking member permit the locking member to be rotated so the teeth align with the seat. The teeth are located near a neutral load axis.

Description

A Locking pin and a locking pin arrangement Field of the invention

[001] This invention relates to an arrangement for releasably securing components.

[002] The invention is applicable to securing components which need to be held together during operation, and which need to be separable for maintenance and repair etc.

Background of the invention

[003] Earth moving equipment have ground engaging teeth which are generally held by means of pins to adaptors mounted on earth moving buckets or the like. During use the pins, which are generally located in apertures in the tooth and adaptor, can be made hard to remove because fines from the earth moved by the bucket can make its way into recesses between the apertures and the pins.

[004] While easy installation is a desirable feature, to save equipment down time, easy removal is also desired. However, the disengagement of a pin from a tooth and or adaptor assembly is hampered by the fines compacting in situ which can tend to jam or resist the movement of the pins in the apertures they are located in. summary of the invention

[005] In one aspect, the locking pin arrangement of an embodiment of the present invention differs from the prior arrangement in having a two-piece locking pin.

[006] A first part of the locking pin can include a first retaining shoulder, and a second part can include a second retaining shoulder.

[007] In use, the first and second retaining shoulders can be opposed to define end walls of a retaining seat.

[008] In a further embodiment, the locking pin arrangement can have fewer protrusions and complementary slots.

[009] In another embodiment of the invention, the locking pin arrangement can have the load- bearing protrusions and their complementary slots closer to the neutral axis.

[010] In addition, a locking pin according to an embodiment of the present invention seeks to overcome the problem of jamming of the engagement member and the locking pin in use, as the jamming of these elements makes removal of the locking pin difficult and time consuming. The rim of the seat can be shaped to facilitate counter-rotation of the locking pin when the protrusion is in the seat. The keyway and the protrusions can also have profiled edges for similar reasons. [Oi l] The slots of the locking pin can be in a plane substantially transverse to the axis of the locking pin.

[012] The locking pin can have a keyway and a seat for receiving the protrusion or protrusions.

[013] The seat can be shallower than the keyway.

[014] There can be an elevated stem between the seat and the keyway to prevent unintended displacement of the protrusion from the seat. The term "elevated" is used in this context to indicate that the stem is more distant from the axis of rotation of the locking pin than the seat, which in turn can be further from the axis than the keyway.

[015] The invention provides a two piece locking pin having a first part and a second part, the first and second parts being mutually connectable.

[016] The first and second parts can be connected by a threaded arrangement.

[017] The first part can include a threaded shaft, and the second part can include a threaded bore.

[018] The first part can include a threaded bore and the second part can include a threaded shaft.

[019] The first part can include an insertion channel adapted to permit the first part to be slid over one or more engaging teeth.

[020] The locking pin can be adapted to lock the connection between a first and a second component, and an engagement member can be associated with the first component, wherein the first part can provide at least a first engaging shoulder adapted to engage a first engagement protrusion associated with the first component.

[021] The second part can include a second engagement shoulder to engage a second engagement protrusion associated with the first component.

[022] The first and second engagement protrusions can be respective edges of a first engagement tooth.

[023] The first component can have engagement member first part can include a third engagement protrusion adapted to engage in an aperture in the said one of the components.

[024] The first part can be adapted to be slid into a bore passing through first and second components.

[025] The bore can be a through hole. [026] The bore can be a blind hole. [027] The pin can be removed by detaching the rotation part from the insertion part, withdrawing the rotation part and pushing the insertion part through the outlet opening of the through hole.

[028] A hammer and punch can be used to remove the rotation part.

Brief description of the drawings

[029] An embodiment or embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[030] Figure 1 illustrates the connection arrangement of WO2004/029371;

[031] Figure 2 illustrates a first part of a locking pin;

[032] Figure 3 illustrates a second part of a locking pin;

[033] Figure 4 illustrates an engagement member;

[034] Figure 5 illustrates a section view of the engagement member of Figure 4;

[035] Figure 6 illustrates a pair of components connected by a connection arrangement;

[036] Figure 7 shows an end view of the locking pin part shown in Figure 2.

[037] Figure 8 illustrates a modified version of the components shown in Figure 6, in which a single protrusion is provided.

[038] Figures 9 & 10 show a bayonet coupling arrangement.

[039] Figure 11 shows the insertion part adapted for insertion from the opposite end of the through hole.

Detailed description of the embodiment or embodiments

[040] Figure 1 shows a connection arrangement the subject of WO2004/029371. An adaptor 1 and tooth or replaceable tip 2 are connected by a connection arrangement including the nose 5 on adaptor 1 and the bracket carrying bore hole 7 on replaceable tip 2. The nose 5 includes a pair of parallel overlapped holes 10, 14 which communicate to form a figure eight sectioned bore hole. Hole 10 is adapted to receive locking pin 12, and hole 14 is adapted to receive engaging tooth arrangement 51.

[041] The engaging toothed arrangement 15 includes a toothed array 152 having a plurality of teeth formed on a support bar and mounted on a resilient member 154 having a longitudinal flexure hole 156 to permit flexure of the resilient member 154. The engaging toothed arrangement 15 can be inserted into the hole 14 before the adaptor 1 and replaceable tip 2 are brought together, and is fully retained within the hole 14 in the nose 5. The teeth 152 project into locking pin hole

10.

[042] The locking pin can be inserted into hole 10 via hole 7 in the upper arm of the replaceable tip 2 when the adaptor 1 and tip 2 have been brought together and the connection holes aligned. Locking pin 12 includes a key way 120 which is adapted to permit the pin to be slid over the teeth 152. The slots 122 have a spiral path which is intended to cause the teeth to exert an upward axial force on the locking pin as the pin is rotated to release it from engagement with the teeth of the engagement member 15. When the locking pin 12 is in the fully inserted position so that the teeth 152 are aligned with their corresponding slots 122, the nut 126 on the end of the pin can be used to rotate the locking pin 12 until the teeth are in the register recesses 124. The slots 122 have a depth which decreases from the keyway to the recesses 124 so that, as the pin 12 is rotated, the teeth are pressed back towards the resilient member 154 which is thus under compression when the teeth are located in the register recesses.

[043] Figures 2 and 3 respectively illustrate the lower and upper portions of a two piece locking pin, to replace the pin 12 of figure 1.

[044] In Figure 2 is the insertion part 200 of a locking pin. The insertion part 200 is basically a cylindrical body in which functional elements are formed. The insertion part 200 includes a keyway 202 and a seat groove 204 separated by a stem 206. Optionally a register protrusion 210 may be formed on the stem 206. A threaded blind aperture , indicated by arrow 212 is formed in the stem 206. The insertion part 200 includes a shoulder indicated by arrow 201 which is adapted to engage with a corresponding shoulder of a protrusion such as tooth 404 on the engagement member shown in Figure 4.

[045] Figure 3 shows the rotation part 300 of the locking pin. The rotation part 300 is basically a cylindrical body 302 having a rotation means in the form of hexagonal nut 306 at one end, and a threaded stem 304 projecting from the other end. The threaded stem 304 is adapted to engage the threaded hole at 212 of the insertion part 300. A shoulder 301 on the rotation part is adapted to engage an oppositely facing shoulder of a protrusion of engagement member 400.

[046] Instead of a threaded attachment, other suitable attachment means can be used. For example a bayonet type coupling can be used between the insertion part 200 and the rotation part 300 as shown in Figures 9 & 10.

[047] Figure 9 is a section view of a bayonet coupling 900 having an entry channel 902, a transition channel 904, and a seat chamber 906 arranged to form a wall 908 between the entry channel 902 and the seat chamber 906. A resilient member 910 is provided below the seat chamber 906 to resiliently retain the engagement nose 912 in the chamber. The resilient member 904 can have a tapered lead-in from the transition channel.

[048] Figure 10 is a top view of an arrangement including a bayonet coupling illustrated in Figure 9. A fastening shaft 1014 having a pair of lugs 1012 are shown in entry channels 1002 of a bayonet coupling receptor 1001.

[049] Figures 4 & 5 illustrate an engagement member 400 adapted for use with a locking pin shown in Figures 2 & 3. The engagement member includes a pair of protrusions in the form of teeth 404, 406, integrally formed on a carrier 402. The carrier 402 is partially embedded in a resilient member 410 which can be made of any suitable resilient material such as rubber, polymeric material, or any suitable material. A keying arrangement 412 can be provided on the support 402 to improve the attachment between the resilient body and the support. The edges 414, 416 of the teeth can be profiled to facilitate movement over the locking pin.

[050] Figure 5 shows a section through the engagement member 400 along Lines V-V. The teeth 504, 506 are formed on the support 502. The resilient member 510 is moulded to the support 502 and has a number of apertures such as holes 520 designed to facilitate flexure of the resilient member 510.

[051] As described in more detail with reference to Figure 7, the transitions from the key way 202 to the stem 208 and protrusion 210 are profiled to provide a smooth transit as the locking pin is rotated and the protrusions move relative to the locking pin from the keyway 202 to the seat groove 204, and as the locking pin is turned in the reverse direction to release the connection.

[052] In order for the protrusions to be received in the seat groove 204, they must ride up over the central stem 206 of the locking pin. As shown in Figure 7, the lead-in 716 from the keyway 702 to the stem 710 can be profiled to provide a "nonsticking" arrangement, by being chamfered, radiused, curved or otherwise shaped or profiled to facilitate the transit of the projections from the keyway 702 to the seat groove 704 as the locking pin is rotated.

[053] In addition, the transition 714 from the stem to the seat groove 704 can be profiled to facilitate reverse rotation of the locking pin during which the projections traverse from the seat groove to the keyway.

[054] Similarly, the engaging edges of the protrusions can be profiled to facilitate the rotation of the locking pin on insertion and removal.

[055] The profiling of the edges is provided to reduce the likelihood of jamming of the protrusions and locking pin. [056] Preferably there are no more than two protrusions, as this also assists in reducing the force required to turn the locking pin.

[057] Figure 6 illustrates a section through a pair of components 602, 604 connected by a connection arrangement. For example, component 602 can be a connection adapter for a mining bucket, and component 604 can be tooth for the bucket.

[058] A lug 606 projects from component 602 and has a pair of holes adapted to accommodate a two piece locking pin 608, 618, and an engagement member 610. The hole which contains the locking pin can be a blind hole or a through hole. Preferably, the locking pin hole is a through hole. The engagement member is preferably contained in a blind hole, although the hole may have reduced opening at the "blind" end to facilitate removal of dirt. The engagement member hole will be closed at both ends by the arms 630, 632.

[059] The engagement member 610 can have one or more protrusions 614, 616 which project into the hole containing the locking pin.

[060] Where the engagement member has two or more protrusions, the locking pin can have complementary protrusions, for example 620, which align with the interstices between the engagement protrusions such as the space between the protrusions 614, 616. However, such protrusions on the locking member are not an essential feature of the invention and can be omitted. In the pin assembly of Figure 2, the protrusion 210 is designed to pass between the engagement protrusions 404, 406 so that it is clear of these engagement protrusions when the engagement protrusions are located in the seat groove 204. Thus the protrusion 210 does not interfere with the axial movement of the lower locking pin part 200 if it is being pushed out of the hole.

[061] The resilient member 612 which carries the engagement protrusions and their support can have transverse apertures or holes to facilitate flexure of the resilient member 612.

[062] When the lug 606 is inserted in the arms 630, 632 of the second member 604, the engagement member is effectively closed off.

[063] The assembled two piece locking pin can be inserted through hole 628 with the keyway (202 in Figure 2) facing the protrusions 614, 616. When the locking pin is fully inserted, the protrusions 614, 616 align with the slots (eg, 208 of Figure 2), and the locking pin can be turned via the hexagonal nut (306 of Figure 3), so that the protrusions are received in the seat groove (204 of Figure 2). During the transit of the protrusions from the keyway 202 to the seat groove 204, the protrusions are subject to compressive force as the protrusions ride up over the stem 208. The resilient member 410 is compressed during this transit. When the protrusion seats in the seat groove 204, the compression of the resilient member is partially relieved, but where the seat groove is designed to be shallower than the key way, some residual compression of the resilient member 410 can be retained to hold the protrusion firmly in the seat groove.

[064] As seen in Figure 6, the upper part 608 of the locking pin is threaded into the lower part 618 and inserted through the upper arm 630 of the component 604 via hole 628 and into the aligned hole in the lug 606. The locking pin thus holds component 604 to the lug 606 as the locking pin projects across the upper and lower interfaces between the lug and component 604. The engagement member protrusions prevent the withdrawal of the locking pin when the protrusions are in the seat.

[065] The seat groove is located in relation to the key way so that rotating the hexagonal nut to move the protrusion from the seat to the keyway and release the locking pin is done in a counterclockwise direction. Thus, if the locking pin and engagement member are jammed, the rotation part 608 of the locking pin will unscrew from the insertion part 618. This frees up the insertion part 618 of the locking pin so that it can be pushed through the lower end of the hole in arm 632 if there is no projection on the locking pin which is located in the interstice between protrusions 614, 616 on the engagement member 624. A small hammer (21b or 4 kg) and punch can be used to dislodge the insertion part 200 if it is jammed.

[066] The working loads on this connection will produce either a torque on the locking pin having an axis substantially transverse to the axis of the locking pin and projecting out of the plane of the drawing page which acts on the pin as opposed shear forces at the upper and lower interfaces of the lug 606 and the component 604 , or it will produce parallel shear loads on the upper and lower interfaces between the lug 606 and component 604 depending on the particular load applied to the component 604.

[067] The protrusion 615 can be located close to the neutral axis of the torque, which will normally be about mid-way between the upper and lower interfaces between the lug 606 and the component 604.

[068] The locking pin and engagement member described above differ from those of the prior art in that the protrusions and mating slots are located closer to the centre of locking pin, so that they are nearer to the neutral axis for the torsion load which is a major load applied to the locking arrangement.

[069] In the assembly shown in Figure 8, there is only one protrusion 615. In this arrangement, the shoulder 622 of the lower part 618 and the shoulder 301 (Figure 3) of upper part 608 engage with protrusion 615 to prevent the locking pin from being removed from the connection while the protrusion 615 is in the seat groove 204 (Figure 2). In this arrangement, the locking pin can be assembled and inserted via aperture 628. When the locking pin is to be removed, the hexagonal nut on the upper part 608 is counter-rotated. If the locking pin and protrusion are jammed, the upper part 608 of the locking pin may thus become unscrewed from the lower part 618 of the locking pin. However, because there is no intermediate protrusion on the lower part 618, the lower part can be pushed from the hole via the lower opening in arm 632.

[070] Figure 11 shows an insertion part 1100 adapted fro insertion from the opposite end to that of a fully assembled locking pin. The insertion part is a cylindrical body 1102 with a seat 1104 and threaded bore 1112. This insertion part can be inserted from the opposite end to that in which the rotation part is inserted and the two parts can be threaded together in situ. A slot 1120, hexagonal nut or protrusion can be formed on the end remote from the threaded bore to facilitate threading the two parts together.

[071] While the above embodiments have been described in the context of earthmoving equipment, the invention and embodiments can be applied to a wide variety of components as described in WO2004/029371, the disclosure of which is incorporated herein by reference. Notwithstanding, any reference herein to this or other known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application.

[072] Where ever it is used, the word "comprising" is to be understood in its "open" sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of". A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear.

[073] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention.

[074] While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

Claims

1. A locking pin adapted for insertion into a locking pin hole passing at least part way through first and second components, wherein the locking pin is a two part locking pin, a first part including a first retaining shoulder, and a second part including a second retaining shoulder.

2. A locking pin as claimed in claim 1, wherein a first part of the two-part locking pin, referred to as the insertion part, includes a keyway adapted to permit the insertion of the insertion pin over one or more engagement protrusions in a locking pin hole.

3. A locking pin as claimed in claim 2, wherein the insertion part includes a seat.

4. A locking pin as claimed in claim 3, wherein the seat is a groove.

5. A locking pin as claimed in claim 3 or claim 4, wherein the seat is shallower than the keyway.

6. A locking pin as claimed in any one of claims 3 to 5, wherein there is a slot between the keyway and the seat.

7. A locking pin as claimed in any one of claims 2 to 6, wherein the insertion part includes a first retaining shoulder adapted for engaging a first end of the or one of the protrusions.

8. A locking pin as claimed in claim 7, wherein the first retaining shoulder is adapted, in use, to face away from the outlet end of a through hole.

9. A locking pin as claimed in any one of the preceding claims, wherein a second part of the two-part locking pin, referred to as the rotation part, includes rotation means.

10. A locking pin as claimed in claim 9, wherein the rotation part includes a second retaining shoulder opposed to the first retaining shoulder.

11. A locking pin as claimed in claim 10, wherein the first and second retaining shoulders define first and second end walls of the seat groove in the assembled locking pin.

12. A locking pin including an insertion part as claimed in any one of claims 2 to and a rotation part as claimed in any one of claims 9 or 10, wherein the insertion part and the rotation part include complementary attachment means.

13. A locking pin as claimed in claim 12, wherein the attachment means is threaded attachment means.

14. A locking pin as claimed in claim 12, wherein the attachment means is a bayonet coupling.

15. A locking pin insertion part including a keyway and a seat.

16. An insertion part as claimed in claim 15, wherein the keyway is linked to the seat via a slot.

17. An insertion part as claimed in claim 15 or 16, wherein the seat is a groove.

18. An insertion part as claimed in any one of claims 15 to 17, wherein the seat is shallower than the keyway.

19. An insertion part as claimed in any one of claims 15 to 18, including a first register shoulder for engaging a first end of the or one of the protrusions.

20. An insertion part as claimed in claim 19, wherein, in use, the first register shoulder is adapted to face away from the outlet end of a through hole.

21. A locking pin rotation part including rotation means and attachment means.

22. A rotation part as claimed in claim 21 , wherein the attachment means are adapted to engage with complementary attachment means on a locking pin insertion part.

23. A locking pin engagement member including one or more protrusions located proximate a neutral axis.

24. An engagement member adapted for insertion in an engagement member hole passing at least part way through first and second components, the engagement member including one or more protrusions adapted to project into an adjacent parallel hole, the protrusion or protrusions being formed near a neutral axis defined when the engagement member is inserted in the engagement member hole.

25. An engagement member as claimed in claim 23 or 24, wherein the or each protrusion is a tooth.

26. An engagement member as claimed in any one of claims 23 to 25, wherein the protrusion or protrusions are formed on a support member.

27. An engagement member as claimed in any one of claims 23 to 26, wherein the projections are mounted on a resilient member.

28. An engagement member as claimed in any one of claims 23 to 27, wherein the first end of the protrusion faces the outlet of the through hole.

29. An engagement member as claimed in any one of claims 23 to 28, including fewer than three protrusions and complementary slots.

30. A locking pin having slots which are substantially transverse to the axis of the locking pin.

31. A locking pin arrangement including a two piece locking pin and an engagement member, the engagement member including protrusions proximate a neutral axis and the locking pin including complementary slots proximate a neutral axis.

32. A locking pin arrangement as claimed in claim 31, wherein locking pin includes an insertion part adapted to be slid into a bore passing through first and second components.

33. A locking pin arrangement as claimed in claim 32, wherein the bore is a through hole.

34. A locking pin arrangement as claimed in claim 32, wherein the bore is a blind hole.

35. A method of removing a two part locking pin including a rotation part and an insertion part inserted in an insertion pin through hole forming part of a connection arrangement between two components, the method including the steps of disconnecting the rotation part from the insertion part, and pushing the insertion part through an outlet opening of the locking pin hole.

36. A method as claimed in claim 35, including the step of tapping the insertion part with a hammer.

37. A method as claimed in claim 35, including the step of forcefully striking the insertion part with a hammer.

38. A two-part locking pin substantially as herein described with reference to the accompanying drawings.

39. A rotation part of a two-part locking pin substantially as herein described with reference to the accompanying drawings.

40. An engagement member substantially as herein described with reference to the accompanying drawings.

41. A method of removing a two-part locking pin substantially as herein described with reference to the accompanying drawings.