GB1575862A - Track lin connection for a vehicle endless track - Google Patents

Description

(54) CONNECTION FOR A VEHICLE ENDLESS TRACK (71) We, CATERPILLAR TRACTOR CO., a corporation organized and existing under the laws of the State of California, United States of America, of 100 N. E. Adams Street, Peoria, Illinois 61629, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: - The present invention relates to track links for a track assembly of a crawler vehicle.

Overlapping track links of crawler vehicle track assemblies are usually interconnected by a pin extending therethrough.

The links and pin are usually engaged by a press fit. A bushing is generally rotatably mounted on the pin and lubricating fluid stored in a reservoir formed in the pin is directed out of the pin to the pin-bushing interface. A seal at the pin-bushing interface limits leakage of the fluid. Stresses in the links usually result in lateral movement of the links relative to the pin. As a result, the seal at the pin-pushing interface may become ineffective and thus permit excessive leakage and loss of the lubricant. The pins and links have been secured, such as by welding, to limit lateral link movement but this is undesirable since removal of the pin is made difficult when link replacement is required.

In view of the above, it would be advantageous to provide a device for limiting lateral movement of the links relative to the pin which device is readily removable for link replacement which overcomes the problems associated with the prior art.

According to the present invention therefore a pair of track links for track assembly of a crawler vehicle are interconnected by a connecting pin extending through the links, the pin including an axial reservoir formed therein for retaining lubricating fluid and at least one end of the pin having an internally screw-threaded portion and being fitted with a keeper for limiting lateral movement of the links; the keeper comprising a screw threaded plug portion in engagement with the screwthreaded portion of the pin and including a bore formed therethrough, a retainer -portion connected to the plug portion con centrate therewith and radially outwardly extending therefrom, a link bearing surface formed on the retainer portion radially outwarly spaced from the plug portion, and a seal member between the plug portion and the retainer portion.

An example of a crawler vehicle track assembly incorporating a link keeper con structed in accordance with the invention is illustrated in the accompanying drawings, -in which: Figure 1 is a partial plan view illustrating the keeper retaining a track link on a link pin; and Figure 2 is an isometric view illustrating the keeper.

Referring now to the drawings, Figure 1 generally illustrates adjacent track shoes 10, 12 of a track type vehicle linked together by overlapping mating links 14, 16.

The links are interconnected by a mount -ing pin 18 which extends through the links.

Pin 18 includes a reservoir 20 formed axially therethrough for retaining lubricating fluid as is well known.

A link keeper 22 is mounted on pin 18 and includes a plug portion 24 threadedly mounted in pin 18. Axial bore or conduit 26 is formed through plug portion 24 and a resilient member 28 is sealingly engaged within the conduit. A retainer portion 30 of keeper 22 is formed with plug portion 24 and includes a bearing surface 32 for engaging and retaining adjacent link 16 on pin 18. A sealing "0" ring 34 is carried by keeper 22 between plug portion 24 and retainer portion- 30.

More specifically, track links 14 are connected to the track shoe 10 such as by bolts 36, or the like, in the well known manner. Links 14 include a bore 38 for accommodating a press fit with bushing 40.

Links 16 are similarly connected to track shoe 12 by bolts 37 and include a bore 42 for accommodating a press fit with pin 18.

Links 16 also include annular groove 44 for accommodating an annular resilient seal 46 for sealing against leakage of lubricating fluid. Also, an annular thrust ring 48 is provided in groove 44 to avoid overcompression of seal 46 due to possible lateral movement of bushing 40 as is well down. A boss 50 is usually formed on links 16 to increase the area of press fit contact between pin 18 and link 16.

Pin 18 is generally well known and includes axial bore 21 forming the reservoir 20 for retaining 'lubricating fluid. Passage 52 is provided in pin 18 to conduct lubricating fluid from reservoir 20 to lubricate and reduce friction due to relative movement at interface 54 between bushing 40 and pin 18. A resilient sealing plug, similar to that shown at 28, including expander 29, is well known and is generally used to seal the lubricating fluid in reservoir 20.

However pin 18 and keeper 22 are structurally and functionally unique since pin 18 includes a threaded counterbore 56 formed therein for receiving mating threaded plug portion 24 of keeper 22. Also, bore 26 formed through lug portion 24 accommodates plug seal 28.

Link 'keeper 22, FIGS. 1 and 2, provides a means of limiting lateral movement of links 14,16 and also provides access to pin -reservoir 20. Keeper 22 is preferably annular and formed of a suitable fabricated steel. The keeper. includes threaded plug portion 24 which extends along the centrodial axis of the keeper for threaded engage ment with counterbore 46. The axial bore 26 is formed through plug portion 24 for providing access to pin reservoir 20. Retainer portion30 is preferably integratedly formed with plug portion 24 and is also preferably concentric therewith and radi wally outwardly extending therefrom. Retainer portion 30 includes an annular bearing surface such as radial face 32 for bearing against link boss 50 thus limiting lateral movement of the links. Also; retainer por tion 30 aids in protecting pin 18 and boss 50 from excess scuffing. An annular groove 58 is formed in keeper 22 preferably between plug portion 24 and bearing surface 32. The annular resilient sealing "0" ring 34, of a suitable sealing material, is carried in groove 58 for sealingly closing the engagement of keeper 22 with pin 18. Retainer portion 30 preferably includes a hexagonal head type anatomy, shown at 60, similar to a bolt head. Alternatively, retainer portion 30 can include spaced bores 62. Thus, either the hex head 60 or the spaced bores 62 provide a tool engaging means on keeper 22 for engagement with an associated tool for mounting the keeper with or removing the keeper 22 from pin 18. For example, hex head 60 can accommodate a similarly shaped well known hexsocket wrench, or the like, and spaced bores 62 can accommodate a well known spanner wrench.

In operation, with links 14,16 interconnected by pin 18, keeper 22 can be threaded into pin 18 until bearing surface 32 is sufficiently tightly urged against boss -50 to prevent lateral link movement. Plug 28 and expander 29 are inserted into bore 26 to seal lubricating fluid in reservoir 20.

Seal 34 sealingly engages keeper 22 in pin 18. Keeper 22 can be engaged with and -removed from pin 18 either by a hex-head socket type wrench or by a spanner wrench.

The foregoing has described a readily removable link keeper device for limiting lateral movement of track links relative to their interconnecting pin.

WHAT WE CLAIM IS: - 1. A pair of track links for track assembly of a crawler vehicle, the track links being interconnected by a connecting pin extending through the links, the pin including an axial reservoir formed therein for retaining lubricating fluid and at least one end of the pin having an internally screw-threaded portion and being fitted with a keeper for limiting lateral movement of the links; the keeper comprising a screw threaded plug portion in engagement with the screw-threaded portion of the pin and including a bore fdrmed therethrough, a retainer portion connected to the plug portion concentric therewith and radially outwardly extending therefrom, a link bearing surface formed on the retainer portion radially outwardly spaced from the plug portion, and a seal member between -the plug portion and the retainer portion.

2. A pair of track links according to claim 1, wherein the keeper further comprises a resilient member sealingly engaged within the bore in the plug portion.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. by keeper 22 between plug portion 24 and retainer portion- 30. More specifically, track links 14 are connected to the track shoe 10 such as by bolts 36, or the like, in the well known manner. Links 14 include a bore 38 for accommodating a press fit with bushing 40. Links 16 are similarly connected to track shoe 12 by bolts 37 and include a bore 42 for accommodating a press fit with pin 18. Links 16 also include annular groove 44 for accommodating an annular resilient seal 46 for sealing against leakage of lubricating fluid. Also, an annular thrust ring 48 is provided in groove 44 to avoid overcompression of seal 46 due to possible lateral movement of bushing 40 as is well down. A boss 50 is usually formed on links 16 to increase the area of press fit contact between pin 18 and link 16. Pin 18 is generally well known and includes axial bore 21 forming the reservoir 20 for retaining 'lubricating fluid. Passage 52 is provided in pin 18 to conduct lubricating fluid from reservoir 20 to lubricate and reduce friction due to relative movement at interface 54 between bushing 40 and pin 18. A resilient sealing plug, similar to that shown at 28, including expander 29, is well known and is generally used to seal the lubricating fluid in reservoir 20. However pin 18 and keeper 22 are structurally and functionally unique since pin 18 includes a threaded counterbore 56 formed therein for receiving mating threaded plug portion 24 of keeper 22. Also, bore 26 formed through lug portion 24 accommodates plug seal 28. Link 'keeper 22, FIGS. 1 and 2, provides a means of limiting lateral movement of links 14,16 and also provides access to pin -reservoir 20. Keeper 22 is preferably annular and formed of a suitable fabricated steel. The keeper. includes threaded plug portion 24 which extends along the centrodial axis of the keeper for threaded engage ment with counterbore 46. The axial bore 26 is formed through plug portion 24 for providing access to pin reservoir 20. Retainer portion30 is preferably integratedly formed with plug portion 24 and is also preferably concentric therewith and radi wally outwardly extending therefrom. Retainer portion 30 includes an annular bearing surface such as radial face 32 for bearing against link boss 50 thus limiting lateral movement of the links. Also; retainer por tion 30 aids in protecting pin 18 and boss 50 from excess scuffing. An annular groove 58 is formed in keeper 22 preferably between plug portion 24 and bearing surface 32. The annular resilient sealing "0" ring 34, of a suitable sealing material, is carried in groove 58 for sealingly closing the engagement of keeper 22 with pin 18. Retainer portion 30 preferably includes a hexagonal head type anatomy, shown at 60, similar to a bolt head. Alternatively, retainer portion 30 can include spaced bores 62. Thus, either the hex head 60 or the spaced bores 62 provide a tool engaging means on keeper 22 for engagement with an associated tool for mounting the keeper with or removing the keeper 22 from pin 18. For example, hex head 60 can accommodate a similarly shaped well known hexsocket wrench, or the like, and spaced bores 62 can accommodate a well known spanner wrench. In operation, with links 14,16 interconnected by pin 18, keeper 22 can be threaded into pin 18 until bearing surface 32 is sufficiently tightly urged against boss -50 to prevent lateral link movement. Plug 28 and expander 29 are inserted into bore 26 to seal lubricating fluid in reservoir 20. Seal 34 sealingly engages keeper 22 in pin 18. Keeper 22 can be engaged with and -removed from pin 18 either by a hex-head socket type wrench or by a spanner wrench. The foregoing has described a readily removable link keeper device for limiting lateral movement of track links relative to their interconnecting pin. WHAT WE CLAIM IS: -

1. A pair of track links for track assembly of a crawler vehicle, the track links being interconnected by a connecting pin extending through the links, the pin including an axial reservoir formed therein for retaining lubricating fluid and at least one end of the pin having an internally screw-threaded portion and being fitted with a keeper for limiting lateral movement of the links; the keeper comprising a screw threaded plug portion in engagement with the screw-threaded portion of the pin and including a bore fdrmed therethrough, a retainer portion connected to the plug portion concentric therewith and radially outwardly extending therefrom, a link bearing surface formed on the retainer portion radially outwardly spaced from the plug portion, and a seal member between -the plug portion and the retainer portion.

2. A pair of track links according to claim 1, wherein the keeper further comprises a resilient member sealingly engaged within the bore in the plug portion.

3. A pair of track links according to

claim 1 or claim 2, further comprising tool engaging means formed on the keeper for engagement with an associated tool for rotation of the keeper.

4. A pair of track links according to any of claims 1 to 3, wherein the screwthreaded portion of the pin comprises a threaded counterbore axially extending into the reservoir.

5. A pair of track links according to claim 1, substantially as described with reference to the accompanying drawings.

6. A track assembly, for a crawler vehicle, including a pair of track links according to any of the preceding claims.