IMPROVEMENTS IN OR RELATING TO TRACK APPARATUS

Abstract

A link member for a continuous track system comprising two side members, and two pin members, wherein the two side members oppose each other and are joined by the two pin members, and wherein the pin members are longitudinal members having a lateral cross section with a single axis of symmetry.

Claims

1. A link member for a continuous track system comprising: two side members; and two pin members, wherein the two side members oppose each other and are joined by the two pin members, and wherein the pin members are longitudinal members having a lateral cross section with a single axis of symmetry, or wherein the pin members are longitudinal members having an ovate lateral cross section.

2-5. (canceled)

6. The link member of claim 1, wherein the lateral cross section of each pin member is substantially the same shape along the entire length of the pin member.

7. (canceled)

8. The link member of claim 1, wherein the axis of symmetry of the lateral cross section of each pin member is perpendicular to the longitudinal axis of the pin member.

9. The link member of claim 1, wherein the axis of symmetry of the lateral cross section of each pin member is parallel to the longitudinal axis of each side member.

10. (canceled)

11. The link member of claim 1, wherein the lateral cross section of each pin member is ovate in shape, or ovate shaped.

12. The link member of claim 1, wherein the lateral cross section of each pin member includes a longitudinal axis and a lateral axis, the longitudinal axis being aligned with the axis of symmetry.

13. The link member of claim 1, wherein the lateral cross section has a length in the direction of the longitudinal axis and a width in the direction of the lateral axis, the length of the lateral cross section being greater than the width of the lateral cross section.

14. The link member of claim 1, wherein the lateral cross section of each pin member has a first portion and a second portion, the first portion being partially circular in shape and the second portion being partially circular in shape and the second portion being partially circular in shape.

15. (canceled)

16. The link member of claim 14, wherein the first portion of the pin member has a first radius and the second portion of the pin member has a second radius, the first radius being greater that the second radius.

17-19. (canceled)

20. The link member of claim 14, wherein the first portions of the lateral cross sections of each pin member are arranged to face each other.

21. The link member of claim 14, wherein the center of the partial circle of the first portion of the lateral cross section lies on the axis of symmetry of the lateral cross section.

22. The link member of any of claim 15, wherein the center of the partial circle of the second portion of the lateral cross section lies on the axis of symmetry of the lateral cross section.

23. The link member of claim 15, wherein the center of the partial circle defined by the radius of the first portion lies outside the circle defined by the radius of the second portion and the center of the partial circle defined by the radius of the second portion lies outside the circle defined by the radius of the first portion.

24-26. (canceled)

27. A continuous track system comprising: a plurality of track plates, wherein each track plate includes two track plate links, the track plate links being located at opposite ends of the track plate; and a plurality of the link members of claim 1 for connecting adjacent track plate links together.

28-29. (canceled)

30. The continuous track system of claim 14, wherein each track plate link includes a pin member engaging portion, each pin member engaging portion including an elongate U-shaped channel portion.

31-55. (canceled)

56. The continuous track system of claim 27, wherein each pin member of each link member includes a track plate link engaging portion, the track plate link engaging portion being located on the inner surface, or inwardly facing surface, of the pin member.

57. The continuous track system of claim 56, wherein the track plate link engaging portion is at least partially complementary in shape to the pin member engaging portion of the track plate link.

58-61. (canceled)

62. The continuous track system of claim 30, wherein each pin member and each track plate link are configured such that there is between a 5 and a 180 contact area between the track plate link engaging portion and the pin member engaging portion, measured from the center point of the pin member.

63. A track plate for a continuous track system comprising: a track plate link, the track plate link being attached to the track plate; and a link member, for connecting the track plate link to an adjacent track plate link, the link member comprising: two side members; and two pin members, wherein the two side members oppose each other and are joined by the two pin members, and wherein the pin members are longitudinal members having a lateral cross section with a single axis of symmetry, or are longitudinal members having an ovate lateral cross section.

64. (canceled)

65. The track plate of claim 63, wherein the link member comprises: two side members; and two pin members, wherein the two side members oppose each other and are joined by the two pin members, and wherein the pin members are longitudinal members having a lateral cross section with a single axis of symmetry, or wherein the pin members are longitudinal members having an ovate lateral cross section, and wherein the lateral cross section of each pin member is substantially the same shape along the entire length of the pin member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0248] Embodiment of the present invention will now be described, by way of example, with reference to the drawings, in which:

[0249] FIG. 1 is a perspective view of a continuous track system according to the present invention;

[0250] FIG. 2 is a schematic side view of the track system of FIG. 1;

[0251] FIG. 3 is a partial side view of the track system of FIG. 1;

[0252] FIG. 4a is side view of a track plate according to the present invention;

[0253] FIG. 4b is a plan view of two joined track plates of FIG. 4a;

[0254] FIG. 5a is a perspective view of a link member according to the present invention;

[0255] FIG. 5b is a plan view of the link member of FIG. 5a;

[0256] FIG. 5c is a side view of the link member of FIG. 5a;

[0257] FIG. 5d is a cross sectional view along section A-A of FIG. 5b;

[0258] FIG. 5e is a cross sectional end along section B-B of FIG. 5b;

[0259] FIG. 5f is an end view of the link member of FIG. 5a; and

[0260] FIG. 6 is a schematic in use side view of the link member of FIG. 5a.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0261] With reference to FIGS. 1 to 4b a continuous track system 10 is illustrated. In the embodiment illustrated and described here the track system 10 is fitted to two-wheels 10a of a four-wheeled vehicle. However, it should be appreciated that the track system 10 may be suitable for use with a vehicle with a greater number of wheels, or a different arrangement of wheels.

[0262] The track system 10 is made up of a number of track plates 10b, track plate links 10c, track paws 10d and link members 12.

[0263] The track plates 10b may be shaped to suite the particular use of the track system 10, i.e. the type of ground and expected weather conditions where the track system 10 will be used. Each track plate 10 may also include one or more spikes 10f (anti-skid spikes).

[0264] As best illustrated in FIGS. 3, 4a and 4b, each track plate 10b includes two track plate links 10c, each track plate link 10c being attached at an end portion 10g of the track plate 10b. The track plate links 10c are typically welded to the track plate 10b.

[0265] The track paws 10d are used to retain the wheels 10a within the track system 10 when in use. As best illustrated in FIGS. 3, 4a and 4b, each track plate 10b includes two track paws 10d, each track paw 10d being attached at an end portion 10g of the track plate 10b. The track paws 10d are also attached to the track plate link 10c. The track paws 10d are typically welded to the track plate 10b and the track plate link 10c. The track paws 10d are typically welded to the track plate link 10c in a gap between two pin member engaging portions 10i.

[0266] The link members 12 are used to connect adjacent track plates 10b together. The link members 12 achieve this by engaging with the track plate links 10c. Each track plate 10b is associated with four link members 12, each track plate link 10c being associated with a pair of link members 12. As described further below, each link member 12 is moveably connected to the track plate link 10c such that the link member 12 can pivot or rotate relative to the track plate 10b and track plate link 10c.

[0267] The link member 12 forms part of the present invention and is illustrated in more detail in FIGS. 5a to 5f.

[0268] The link member 12 comprises two side members, or flanges, 12a and two pin members 12b. As best illustrated in FIG. 5b, the link member 12 is arranged such that the two side members 12a oppose each other and are joined together by the two pin members 12b.

[0269] The link member 12 is typically forged from steel as a single piece. The steel may be a boron alloy steel. However, it should be appreciated that other materials may be used depending on the requirements of the link member 12 and the track system 10.

[0270] As best illustrated in FIG. 5b, the side members 12a and the pin members 12b are arranged such that the link member 12 is substantially square shaped in plan view. Here the side members 12a are arranged to be substantially perpendicular to the pin members 12b. The link member 12 has a longitudinal axis 12c and a lateral axis 12d. In the embodiment illustrated and described here the link member 12 is symmetrical along the lateral axis 12d. The link member 12 may also be symmetrical along the longitudinal axis 12c. Where the link member 12 is symmetrical along the longitudinal axis 12c, the side members 12a would be identical.

[0271] The link member 12 may be between 40 mm and 250 mm long, between 50 mm and 120 mm wide and between 25 mm and 55 mm tall. The exact size of the link member 12 may be dependent on the type of track system required and the use thereof.

[0272] As best illustrated in FIGS. 5a and 5b, the side members 12a are substantially elongate planar members and are arranged to be parallel to one another. Each side member 12a includes a longitudinal axis 12e.

[0273] The link member 12 includes a first side member 12a and a second side member 12a. The first side member 12a may be an inner side member and the second side member 12a may be an outer side member. The first side member 12a is arranged to be closer to the tyre 10a that the second side member 12a.

[0274] In the embodiment illustrated and described here the first side member 12a and the second side member 12a are non-identical, as described further below. However, it should be appreciated that the first side member 12a and the second side member 12a may be identical.

[0275] As best illustrated in FIGS. 5b, 5e and 5f, each side member 12a may have a curved outwardly facing surface 12f and a substantially planar inwardly facing surface 12g. Each curved outwardly facing surface 12f may have one or more portions that are partially spherical in shape. The planes of the planar inwardly facing surfaces 12g are substantially parallel. The curved outwardly facing surfaces 12f and the planar inwardly facing surfaces 12g are smooth to prevent excessive wear on the tyre 10a of the wheel 10a. It should be appreciated that the inwardly facing surfaces 12g may not be exactly planar and may have a low apex that runs parallel to the longitudinal axis thereof. That is, inwardly facing surfaces 12g may have a 6 draft angle. The draft angle may also be between 3 and 9. This is a result of the forging process.

[0276] With reference to FIGS. 5a, 5c and 5d, the side members 12a have bulbous portions, or lobes 12h, located at each end thereof.

[0277] As best illustrated in FIGS. 5a, 5e and 5f, the second side member 12a has different dimensions compared to the first side member 12a. In the embodiment illustrated and described here the second side member 12a is taller than the first side member 12a. The second side member 12a has a height of 48.0 mm, compared to a height of 40.0 mm of the first side member 12a. Providing a link member 12 that has a larger outer side member than an inner side member reduces the risk of the link member 12 twisting relative to the track plate link 10c. That is, the larger outer side member has a greater area of contact with the track plate link 10c, which prevents the link member 12 from twisting. Preventing the link member 12 from twisting ensures that the only the pin members 12b of the link member 12 engage with the track plate link 10c and not any other part of the link member 12, i.e. that the link runs true throughout its life.

[0278] In the embodiment illustrated and described here the first side member 12a is 121.0 mm long and the second side member 12a is 123.3 mm long.

[0279] The distance between the inwardly facing surfaces 12g of the side members 12a are 52.5 mm.

[0280] As illustrated in FIGS. 5e and 5f, the side members 12a have a height that is greater than the thickness, or width, of the pin members 12b.

[0281] However, it should be appreciated that the dimensions of the side members 12a may be configured or altered to suit requirements of use of the link member 12 and the track system 10.

[0282] As best illustrated in FIGS. 5b, 5e and 5f, the pin members 12b are longitudinal, or elongate, members having a longitudinal axis 12i. The pin members 12b are arranged to be substantially parallel to one another and substantially perpendicular to the side members 12a.

[0283] As best illustrated in FIGS. 5e and 5f, the pin members 12b are arranged such that they join the side members 12a at a location which is between the lowest portion and the highest portion of the side member 12a. The effect of this is that it allows the side members 12a to be flanges, with shoulder portions 12l. The shoulder portions 12l create a flange surface 12m which circumscribes the inwardly facing surface 12g of each side member 12a. In use, the flange surfaces 12m may contact the track plate link 10c and limit the lateral movement thereof. The flange surfaces 12m also prevent twisting of the link members 12a when in use. The flange surface 12m of the second side member 12a is larger than the flange surface 12 of the first side member 12a.

[0284] As best illustrated in FIG. 5d, the pin members 12b have a lateral cross section 12j. The lateral cross section 12j has a single axis of symmetry 12k. As best illustrated in FIGS. 5d and 5e, the axis of symmetry 12k of the lateral cross section 12j of each pin member 12b is perpendicular to the longitudinal axis 12i of the pin member 12b and parallel to the longitudinal axis 12c of the side members 12a. The axes of symmetry 12k of the lateral cross sections 12j of each pin member 12b are also parallel.

[0285] In the embodiment illustrated and described here, and as best illustrated in FIG. 5d, the lateral cross section 12j of each pin member 12b is generally ovate in shape. That is, the lateral cross section 12j of each pin member 12b has a shape that resembles, or is at least similar to, the longitudinal section of an ovoid. It should be appreciated that the lateral cross section 12j of each pin member 12b may not necessarily exactly match the shape of an ovate, or the longitudinal section of an ovoid, but it could be this general shape or similar thereto.

[0286] The lateral cross section 12j of each pin member 12b is substantially the same shape along the entire length of the pin member 12b. The pin members 12b are therefore in the shape of extended ovates. Furthermore, the pin members 12b are substantially identical in shape.

[0287] Again as best illustrated in FIG. 5d, the lateral cross section 12j has a longitudinal axis 12n, which is aligned with the axis of symmetry 12k, and a lateral axis 12o that is perpendicular to the longitudinal axis 12n. The lateral cross section 12j has a length in the direction of the longitudinal axis 12n and a width in the direction of the lateral axis 12o. The length of the lateral cross section 12j is greater than the width of the lateral cross section 12j. The maximum length of the lateral cross section 12j is greater than the maximum width of the lateral cross section 12j.

[0288] The lateral cross section 12j of each pin member 12b has a first portion 12p and a second portion 12q. The first and second portions 12p and 12q are partially circular in shape. The partial circle of the first portion 12p has a first radius 12p and the partial circle of the second portion 12q has a second radius 12q, the first radius 12p being larger than the second radius 12q. The first radius 12p may be 15 mm and the second radius 12q may be 12.2 mm. However, it should be appreciated that these radii may be different depending on the requirements of the link member 12 and use of the track system 10. Each pin member 12b may thus have a partially cylindrical first portion 13 and a partially cylindrical second portion 15.

[0289] The centre 12r of the circle defined by the radius 12p of the first portion 12p lies on the axis of symmetry 12k of the lateral cross section 12j. The centre 12s of the circle defined by the radius 12q of the second portion 12q lies on the axis of symmetry 12k of the lateral cross section 12j. The centre 12r of the circle defined by the radius 12p of the first portion 12p lies outside the circle defined by the radius 12q of the second portion 12q. Similarly, the centre 12s of the circle defined by the radius 12q of the second portion 12q lies outside the circle defined by the radius 12p of the first portion 12p.

[0290] In the embodiment illustrated and described here the lateral cross section 12j has a maximum length of 31.5 mm and a maximum width of 27 mm. However, it should be appreciated that the length and width may be different depending on the requirements of the link member 12 and use of the track system 10.

[0291] Furthermore, the line joining the points where the length of the lateral cross section 12j is at its maximum is aligned with the axis of symmetry 12k of the lateral cross section 12j and the line joining the points where the width of the lateral cross section 12j is at its maximum is perpendicular to the axis of symmetry 12k of the lateral cross section 12j. The point where the line joining the points where the length of the lateral cross section 12j is at its maximum and the line joining the points where the width of the lateral cross section 12j is at its maximum intersect may be the centre point 12t of the lateral cross section 12j. This may be the centre point of each pin member 12b. The distance between centre points 12t of each pin member is 85 mm.

[0292] The distance between the inwardly facing surfaces 12g of the pin members 12b is 58 mm. Furthermore, the pin members 12b are 52.5 mm long. However, it should be appreciated that this dimension may be different depending on the requirements of the link member 12 and use of the track system 10.

[0293] As best illustrated in FIG. 5d, the first portions 12p of the pin members 12b are arranged to face each other. That is, the first portions 12p of the pin members 12b face inwards and the second portions 12q of the pin members 12b face outwards.

[0294] With reference to FIG. 6 the link member 12 is illustrated schematically in use with a track plate link 10c. It should be appreciated that only the lateral cross sections 12j of the pin members 12b of the link member 12 have been illustrated for clarity. As is known with continuous track systems, the link members 12 are arranged with the track plate links 10c to allow respective movement between each link member 12 and each track plate link 10c.

[0295] As illustrated, the track plate link 10c is a longitudinal member having a lateral cross section 10h that is C-shaped. The thickness of each track plate link 10c is 20 mm.

[0296] Each track plate link 10c includes a pin member engaging portion 10i. The pin member engaging portion 10i is an elongate U-shaped channel portion. As illustrated, the pin member engaging portions 10i are located at opposite ends of the track plate link 10c. Therefore, each track plate link 10c includes two pin member engaging portions 10i.

[0297] The pin member engaging portions 10i are thus concave with a partially cylindrical surface 17. The radius of the partially cylindrical surface 17 is configured to substantially match the radius 12p of the first portion 12p of the lateral cross section 12j and partially cylindrical first portion 13 of the pin member 12b. The partially cylindrical surface 17 of the pin member engaging portions 10h is thus complimentary in shape to the partially cylindrical first portion 13 of the pin members 12b.

[0298] The partially cylindrical first portion 13 of each pin member 12b includes track plate link engaging portions 12u. The track plate link engaging portions 12u thus face the pin member engaging portions 10i.

[0299] The track plate link engaging portions 12u therefore have a partially cylindrical surface 19. The radius of the partially cylindrical surface 19 is configured to substantially match the radius of the partially cylindrical surface 17 of the pin member engaging portions 10i. The track plate link engaging portions 12u are thus complementary in shape to the pin member engaging portions 10i of the track plate link 10c.

[0300] The radius of the partially cylindrical surface 17 of the pin member engaging portions 10i is 15 mm and the radius of the partially cylindrical surface 19 of the track plate link engaging portions 12u is 15 mm. However, it should be appreciated that the radii may be different depending on the requirements of the link member 12 and use of the track system 10.

[0301] Each pin member 12b and each track plate link 10c are configured such that there is approximately a 90 contact area between the track plate link engaging portion 12u and the pin member engaging portion 10i, measured from the centre point 12t of the pin member 12b.

[0302] As illustrated in FIG. 6, the link members 12b connect adjacent track plate links 10c together. That is, a first pin member 12b of a link member 12 is connected with a pin member engaging portion 10i of a first track plate link 10c and a second pin member 12b of the link member 12 is connected with a pin member engaging portion 10i of a second track plate link 10c.

[0303] Providing a link member 12 for a continuous track system as described above reduces the amount of re-tensioning required to be carried out for new track systems.

[0304] Providing a link member 12 having pin members 12b having a lateral cross section 12j as described above ensures that the track plate link engaging portions 12u, and the pin members 12b, are complimentary in shape to the pin member engaging portions 10i of the track pate links 10c.

[0305] In the embodiment illustrated and described here the radius of the partially cylindrical surface 19 of the track plate link engaging portions 12u of the pin members 12b are configured to match the radius of the partially cylindrical surface 17 of the pin member engaging portions 10i of the track plate links 10c. Matching the radii almost eliminates the bedding in period and results in less frequent re-tensioning.

[0306] The present invention also provides an increased contact area between the track plate link engaging portion 12u and the pin member engaging portion 10i. Increasing this contact area also reduces the high initial wear period, which results in a longer life of the component.

[0307] Furthermore, providing a link member 12 whereby the length of the lateral cross section 12j is greater than the width of the lateral cross section 12j maximises material across the critical wear point of the link member 12, which increases the lifespan of the member.

[0308] Providing a link member 12, a track plate 10b and a continuous track system 10 according to the present invention reduces the amount of re-tensioning required.

[0309] Modifications and improvements may be made to the above without departing from the scope of the present invention. For example, although the lateral cross section 12j has been illustrated and described above as being generally ovate in shape, it should be appreciated that the lateral cross section 12j may have other shapes. Similarly, although the lateral cross section 12j has been illustrated and described above as having a single axis of symmetry 12k, it should be appreciated that the lateral cross section 12k may not necessarily have only one axis of symmetry.

[0310] Furthermore, although the link member 12 has been illustrated and described above as having a first side member 12a and a second side member 12a, the first and second side members 12a and 12a having different dimensions, it should be appreciated that the first and second side members 12a and 12a may be identical.