Patent Publication Number: US-2019176915-A1

Title: Improvements in or relating to track apparatus

Description:
FIELD OF THE INVENTION 
     This invention relates to a link member for a continuous track system and a continuous track system. 
     BACKGROUND TO THE INVENTION 
     When new continuous track systems are fitted to wheeled vehicles they will quickly slacken off over the first few days of use. This requires the track system to be re-tensioned. Re-tensioning may involve the replacement of longer track links with shorter track links and often the removal of one or more full track plates from the system. 
     The slackening off of new tracks is a result of the initial wear of all the components of the track system. This is often referred to as “bedding in”. New track systems are required to be re-tensioned frequently during the initial period of use, with this task becoming less frequent as the tracks bed in. 
     Re-tensioning of tracks is time consuming and inconvenient, particularly if track plates have to be removed. 
     The present inventor has appreciated the shortcomings with such known continuous track systems. 
     According to a first aspect of the present invention there is provided 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.       

     The link member may have a longitudinal axis and a lateral axis. The link member may be symmetrical along the longitudinal and/or lateral axes. Alternatively, the link member may be symmetrical along the lateral axis and non-symmetrical along the longitudinal axis. 
     The link member may be formed as a single piece, or single component. The link member may be forged. The link member may be a forged member. The link member may be forged from steel. The steel may be a boron alloy steel. 
     The side members and the pin members may be arranged such that the link member is substantially square shaped in plan view. 
     The link member may be between 40 mm and 250 mm long. The link member may be around 123 mm long. The link member may be between 115 mm and 130 mm long. The link member may be around 115 mm long. 
     The link member may be between 50 mm and 120 mm wide. The link member may be around 90 mm wide. The link member may be between 85 mm and 90 mm wide. 
     The link member may be between 25 mm and 55 mm tall. The link member may be around 48 mm tall. The link member may be between 45 mm and 55 mm tall. 
     The side members may be substantially elongate planar members. Each side member may have a longitudinal axis. 
     The side members may be arranged to be parallel to one another. 
     The side members may be arranged to be substantially perpendicular to the pin members. 
     The side members may be identical. Alternatively, one side member may have a different length, width and/or height that the other side member. Each side member may have differently shaped outwardly facing surface. 
     The side members may have curved outwardly facing surface. At least a portion of the outwardly facing surface of the side member may be at least partially spherical in shape. One or more portions of the outwardly facing surface of the side members may be at least partially spherical in shape. 
     The side members may have substantially planar inwardly facing surfaces. The planes of the surfaces of the two side members may be parallel. 
     The side members may have bulbous portions or lobe portions located at each end thereof. 
     The outwardly facing surfaces and/or the inwardly facing surfaces of the side members may be smooth. 
     The side members may be between 40 mm and 250 mm long. The side members may be around 123 mm long. The side members may be around 121 mm long. The side members may be between 115 mm and 130 mm long. 
     One side member may be an inner side member and the other side member may be an outer side member. The outer side member may be longer than the inner side member. The outer side member may be taller than the inner side member. The outer side member may be thicker than the inner side member. 
     The inner side member may be between 40 mm and 250 mm long. The inner side member may be around 121 mm long. The inner side member may be between 115 mm and 127 mm long. 
     The inner side member may be between 25 mm and 55 mm tall. The inner side member may be around 40 mm tall. The inner side member may be between 35 mm and 45 mm tall. 
     The outer side member may be between 40 mm and 250 mm long. The outer side member may be around 123 mm long. The outer side member may be between 115 mm and 130 mm long. 
     The outer side member may be between 25 mm and 55 mm tall. The outer side member may be around 48 mm tall. The outer side member may be between 45 mm and 55 mm tall. 
     The distance between the inwardly facing surfaces of the side members may be between 40 mm and 100 mm. The distance between the inwardly facing surfaces of the side members may be around 52.5 mm. The distance between the inwardly facing surfaces the side members may be between 50 mm and 55 mm. 
     The side members may have a height that is greater than the height, thickness, or width of the pin members. 
     At least one side member may include a flange surface. The flange surface may circumscribe an inwardly facing surface of the side member. Both side members may include a flange surface. Both flange surfaces may circumscribe an inwardly facing surface of the side member. The flange surface of the second side member may be larger than the flange surface of the first side member. 
     The lateral cross section of each pin member may be substantially the same shape along the entire length of the pin member. 
     The pin members may be substantially elongate members. Each pin member may have a longitudinal axis. 
     The pin members may be substantially parallel to one another. 
     The pin members may be arranged to be substantially perpendicular to the side members. 
     The pin members may be identical. Alternatively, the pin members may be differently shaped. 
     The outer surface of the pin members may be smooth. 
     The distance between the inwardly facing surfaces of the pin members may be between 40 mm and 160 mm. The distance between the inwardly facing surfaces of the pin members may be around 58 mm. The distance between the inwardly facing surfaces the pin members may be between 55 mm and 65 mm. 
     The pin members may be between 40 mm and 100 mm long. The pin members may be around 52.5 mm long. The pin members may be between 45 mm and 60 mm long. 
     The pin members may be arranged such that they join the side members at a location which is between the lowest portion and highest portion of the side member. 
     The axis of symmetry of the lateral cross section of each pin member may be perpendicular to the longitudinal axis of the pin member. 
     The axis of symmetry of the lateral cross section of each pin member may be parallel to the longitudinal axis of each side member. 
     The axes of symmetry of the lateral cross sections of the pin members may be parallel. 
     The lateral cross section of each pin member may be ovate in shape. The lateral cross section of each pin member may be ovate shaped. The lateral cross section of each pin member may be generally ovate in shape. The lateral cross section of each pin member may be generally ovate shaped. 
     The lateral cross section of each pin member may have a shape that resembles the longitudinal section of an ovoid. The lateral cross section of each pin member may have a shape that is generally like the longitudinal section of an ovoid. The lateral cross section of each pin member may be the shape of the longitudinal section of an ovoid. The lateral cross section of each pin member may substantially be the shape of the longitudinal section of an ovoid. 
     The term ovate used throughout this specification is considered to mean a shape that is the shape of the longitudinal section of an ovoid, or is generally the same shape as the longitudinal section of an ovoid. 
     The pin members may be in the shape of extended ovates. 
     The lateral cross section of each pin member includes a longitudinal axis and a lateral axis. The longitudinal axis is aligned with the axis of symmetry. The longitudinal axis is parallel to the axis of symmetry. 
     The lateral cross section may have 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 may be greater than the width of the lateral cross section. 
     The lateral cross section of each pin member may have a first portion and a second portion. The first portion may be partially circular in shape. The second portion may be partially circular in shape. The first portion may have a first radius. The second portion may have a second radius. The first radius may be greater that the second radius. The pin member may thus have a partially cylindrical first portion and a partially cylindrical second portion. 
     The first radius of the first portion may be between 8 mm and 20 mm. The first radius of the first portion may be around 15 mm. The first radius of the first portion may be between 12.5 mm and 17.5 mm. 
     The second radius of the second portion may be between 8 mm and 20 mm. The second radius of the second portion may be around 12.2 mm. The second radius of the second portion may be between 12.5 mm and 17.5 mm. 
     The first portions of the lateral cross sections of each pin member may be arranged to face each other. 
     The first portions of the lateral cross sections of each pin member may face inwards and the second portions of the lateral cross sections of each pin member may face outwards. 
     The centre of the partial circle of the first portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle of the second portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centres of the partial circles of the first and second portions of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the partial circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The centre of the circle defined by the radius of the first portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the second portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The lateral cross section may have a maximum length of around 31.5 mm. The maximum length of the lateral cross section may be between 16 mm and 40 mm. The maximum length of the lateral cross section may be between 25 mm and 35 mm. 
     The pin members may have a maximum width of around 31.5 mm. The maximum width of the pin members may be between 16 mm and 40 mm. The maximum width of the pin members may be between 25 mm and 35 mm. 
     The lateral cross section may have a maximum height of around 27 mm. The maximum height of the lateral cross section may be between 16 mm and 40 mm. The maximum height of the lateral cross section may be between 22 mm and 32 mm. 
     The pin members may have a maximum height of around 27 mm. The maximum height of the pin members may be between 16 mm and 40 mm. The maximum height of the pin members may be between 25 mm and 35 mm. 
     The line joining the points where the length of the lateral cross section is at its maximum may be aligned with the axis of symmetry of the lateral cross section. The line joining the points where the height of the lateral cross section is at its maximum may be perpendicular to the axis of symmetry of the lateral cross section. The point where the line joining the points where the length of the lateral cross section is at its maximum and the line joining the points where the height of the lateral cross section is at its maximum intersect may be the centre point of the lateral cross section. This may be the centre point of each pin member. 
     The distance between the centre points of each lateral cross section of each pin member may be between 40 mm and 200 mm. The distance between the centre points of each lateral cross section of each pin member may be around 75 mm. The distance between the centre points of each lateral cross section of each pin member may be around 85 mm. The distance between the centre points of each lateral cross section of each pin member may be between 75 mm and 85 mm. 
     According to a second aspect of the present invention there is provided 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.   
               

     The link member may be moveably connected to the track plate link. The link member may be connected to the track plate link such that the link member may pivot or rotate relative to the track plate link. 
     The track plate link may include a pin member engaging portion. The pin member engaging portion may be a hook or loop. The pin member engaging portion may be hook shaped. The hook or loop of the pin member engaging portion may include a generally U-shaped channel for receiving the pin member therein. The hook or loop of the pin member engaging portion may include an elongate U-shaped channel portion. 
     The pin member engaging portion may be configured such that, in use, the pin member of the link member is received therein and moves with respect thereto. 
     The track plate link may be a longitudinal member having a lateral cross section that is C-shaped. The track plate link may be a longitudinal member having a lateral cross section that is generally C-shaped. 
     The track plate link may be around 20 mm thick. The track plate link may be between 10 mm and 40 mm thick. 
     The pin member engaging portion may be provided in the lower or upper portion of the track plate link. Pin member engaging portions may be provided in the lower and upper portions of the track plate link. The pin member engaging portions may be located at opposite ends of the track plate link. The track plate link may include two pin member engaging portions, such that two link members may be connected thereto. 
     The link member may have a longitudinal axis and a lateral axis. The link member may be symmetrical along the longitudinal and/or lateral axes. Alternatively, the link member may be symmetrical along the lateral axis and non-symmetrical along the longitudinal axis. 
     The link member may be formed as a single piece, or single component. The link member may be forged. The link member may be a forged member. The link member may be forged from steel. The steel may be a boron alloy steel. 
     The side members and the pin members may be arranged such that the link member is substantially square shaped in plan view. 
     The link member may be between 40 mm and 250 mm long. The link member may be around 123 mm long. The link member may be between 115 mm and 130 mm long. The link member may be around 115 mm long. 
     The link member may be between 50 mm and 120 mm wide. The link member may be around 90 mm wide. The link member may be between 85 mm and 90 mm wide. 
     The link member may be between 25 mm and 55 mm tall. The link member may be around 48 mm tall. The link member may be between 45 mm and 55 mm tall. 
     The side members may be substantially elongate planar members. Each side member may have a longitudinal axis. 
     The side members may be arranged to be parallel to one another. 
     The side members may be arranged to be substantially perpendicular to the pin members. 
     The side members may be identical. Alternatively, one side member may have a different length, width and/or height that the other side member. Each side member may have differently shaped outwardly facing surface. 
     The side members may have curved outwardly facing surface. At least a portion of the outwardly facing surface of the side member may be at least partially spherical in shape. One or more portions of the outwardly facing surface of the side members may be at least partially spherical in shape. 
     The side members may have substantially planar inwardly facing surfaces. The planes of the surfaces of the two side members may be parallel. 
     The side members may have bulbous portions or lobe portions located at each end thereof. 
     The outwardly facing surfaces and/or the inwardly facing surfaces of the side members may be smooth. 
     The side members may be between 40 mm and 250 mm long. The side members may be around 123 mm long. The side members may be around 121 mm long. The side members may be between 115 mm and 130 mm long. 
     One side member may be an inner side member and the other side member may be an outer side member. The outer side member may be longer than the inner side member. The outer side member may be taller than the inner side member. The outer side member may be thicker than the inner side member. 
     The inner side member may be between 40 mm and 250 mm long. The inner side member may be around 121 mm long. The inner side member may be between 115 mm and 127 mm long. 
     The inner side member may be between 25 mm and 55 mm tall. The inner side member may be around 40 mm tall. The inner side member may be between 35 mm and 45 mm tall. 
     The outer side member may be between 40 mm and 250 mm long. The outer side member may be around 123 mm long. The outer side member may be between 115 mm and 130 mm long. 
     The outer side member may be between 25 mm and 55 mm tall. The outer side member may be around 48 mm tall. The outer side member may be between 45 mm and 55 mm tall. 
     The distance between the inwardly facing surfaces of the side members may be between 40 mm and 100 mm. The distance between the inwardly facing surfaces of the side members may be around 52.5 mm. The distance between the inwardly facing surfaces the side members may be between 50 mm and 55 mm. 
     The side members may have a height that is greater than the height, thickness, or width of the pin members. 
     At least one side member may include a flange surface. The flange surface may circumscribe an inwardly facing surface of the side member. Both side members may include a flange surface. Both flange surfaces may circumscribe an inwardly facing surface of the side member. The flange surface of the second side member may be larger than the flange surface of the first side member. 
     The lateral cross section of each pin member may be substantially the same shape along the entire length of the pin member. 
     The pin members may be substantially elongate members. Each pin member may have a longitudinal axis. 
     The pin members may be substantially parallel to one another. 
     The pin members may be arranged to be substantially perpendicular to the side members. 
     The pin members may be identical. Alternatively, the pin members may be differently shaped. 
     The outer surface of the pin members may be smooth. 
     The distance between the inwardly facing surfaces of the pin members may be between 40 mm and 160 mm. The distance between the inwardly facing surfaces of the pin members may be around 58 mm. The distance between the inwardly facing surfaces the pin members may be between 55 mm and 65 mm. 
     The pin members may be between 40 mm and 100 mm long. The pin members may be around 52.5 mm long. The pin members may be between 45 mm and 60 mm long. 
     The pin members may be arranged such that they join the side members at a location which is between the lowest portion and highest portion of the side member. 
     The axis of symmetry of the lateral cross section of each pin member may be perpendicular to the longitudinal axis of the pin member. 
     The axis of symmetry of the lateral cross section of each pin member may be parallel to the longitudinal axis of each side member. 
     The axes of symmetry of the lateral cross sections of the pin members may be parallel. 
     The lateral cross section of each pin member may be ovate in shape. The lateral cross section of each pin member may be ovate shaped. The lateral cross section of each pin member may be generally ovate in shape. The lateral cross section of each pin member may be generally ovate shaped. 
     The lateral cross section of each pin member may have a shape that resembles the longitudinal section of an ovoid. The lateral cross section of each pin member may have a shape that is generally like the longitudinal section of an ovoid. The lateral cross section of each pin member may be the shape of the longitudinal section of an ovoid. The lateral cross section of each pin member may substantially be the shape of the longitudinal section of an ovoid. 
     The pin members may be in the shape of extended ovates. 
     The lateral cross section of each pin member includes a longitudinal axis and a lateral axis. The longitudinal axis is aligned with the axis of symmetry. The longitudinal axis is parallel to the axis of symmetry. 
     The lateral cross section may have 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 may be greater than the width of the lateral cross section. 
     The lateral cross section of each pin member may have a first portion and a second portion. The first portion may be partially circular in shape. The second portion may be partially circular in shape. The first portion may have a first radius. The second portion may have a second radius. The first radius may be greater that the second radius. The pin member may thus have a partially cylindrical first portion and a partially cylindrical second portion. 
     The first radius of the first portion may be between 8 mm and 20 mm. The first radius of the first portion may be around 15 mm. The first radius of the first portion may be between 12.5 mm and 17.5 mm. 
     The second radius of the second portion may be between 8 mm and 20 mm. The second radius of the second portion may be around 12.2 mm. The second radius of the second portion may be between 12.5 mm and 17.5 mm. 
     The first portions of the lateral cross sections of each pin member may be arranged to face each other. 
     The first portions of the lateral cross sections of each pin member may face inwards and the second portions of the lateral cross sections of each pin member may face outwards. 
     The centre of the partial circle of the first portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle of the second portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centres of the partial circles of the first and second portions of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the partial circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The centre of the circle defined by the radius of the first portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the second portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The lateral cross section may have a maximum length of around 31.5 mm. The maximum length of the lateral cross section may be between 16 mm and 40 mm. The maximum length of the lateral cross section may be between 25 mm and 35 mm. 
     The pin members may have a maximum width of around 31.5 mm. The maximum width of the pin members may be between 16 mm and 40 mm. The maximum width of the pin members may be between 25 mm and 35 mm. 
     The lateral cross section may have a maximum height of around 27 mm. The maximum height of the lateral cross section may be between 16 mm and 40 mm. The maximum height of the lateral cross section may be between 22 mm and 32 mm. 
     The pin members may have a maximum height of around 27 mm. The maximum height of the pin members may be between 16 mm and 40 mm. The maximum height of the pin members may be between 25 mm and 35 mm. 
     The line joining the points where the length of the lateral cross section is at its maximum may be aligned with the axis of symmetry of the lateral cross section. The line joining the points where the height of the lateral cross section is at its maximum may be perpendicular to the axis of symmetry of the lateral cross section. The point where the line joining the points where the length of the lateral cross section is at its maximum and the line joining the points where the height of the lateral cross section is at its maximum intersect may be the centre point of the lateral cross section. This may be the centre point of each pin member. 
     The distance between the centre points of each lateral cross section of each pin member may be between 40 mm and 200 mm. The distance between the centre points of each lateral cross section of each pin member may be around 75 mm. The distance between the centre points of each lateral cross section of each pin member may be around 85 mm. The distance between the centre points of each lateral cross section of each pin member may be between 75 mm and 85 mm. 
     Each pin member may include a track plate link engaging portion. The track plate link engaging portion may be located on the inner surface, or inwardly facing surface, of the pin member. The track plate link engaging portions may be arranged such that they face one another. The track plate link engaging portions may have a partially cylindrical surface. 
     The track plate link engaging portion may be complementary in shape to the pin member engaging portion of the track plate link. The track plate link engaging portion may be at least partially complementary in shape to the pin member engaging portion of the track plate link. The track plate link engaging portion may have a portion that is at least partially complementary in shape with a portion of the pin member engaging portion of the track plate link. 
     The pin member engaging portion of the track plate link may have a concave portion. The concave portion may have a partially cylindrical surface. 
     The pin member engaging portion of the track plate link may include a longitudinal channel portion. At least a portion of the longitudinal channel portion may be at least partially complementary in shape with a portion of the track plate link engaging portion of the pin member. At least a portion of the longitudinal channel portion may be concave. The concave portion may have a partially cylindrical surface. 
     At least a portion of the pin member engaging portion of the track plate link may be complementary in shape to at least a portion of the first portion of the pin member. 
     The radius of the concave portion of the longitudinal channel may be substantially the same as the radius of the first portion of the lateral cross section of the pin member. 
     The radius of the concave portion of the longitudinal channel may have a radius between 8 mm and 20 mm. The radius of the concave portion of the longitudinal channel may be around 15 mm. The radius of the concave portion of the longitudinal channel may be between 12.5 mm and 17.5 mm. The radius of the concave portion of the longitudinal channel may be 28 mm. The radius of the concave portion of the longitudinal channel may be 26 mm. 
     The pin member and the track plate link may be configured such that there is approximately a 90° contact area between the track plate link engaging portion and the pin member engaging portion, measured from the centre point of the radius engaging face of the pin member. The pin member and the track plate link may be 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 centre point of the radius engaging face of the pin member. 
     The track plate may comprise two track plate links. Each track plate link may be located at opposite ends of the track plate. Each track plate link may include two pin member engaging portions. The pin member engaging portions may be located at opposite ends of the track plate link. 
     In use, the link member may connect to adjacent track plate links. That is, a first pin member of a link member may be connected with a pin member engaging portion of a first track plate link and a second pin member of the link member may be connected with a pin member engaging portion of a second track plate link. 
     Each track plate link may be associated with two link members. 
     The track plate may include between one and four link members. 
     The track plate may include one or more track paws. Each track paw may be connected to the track plate links. The track paws being configured to at least partially house a tyre of a wheel vehicle when in use. The track plate may include a track paw at each end of the track plate. The track paws may be configured such that the oppose one another. 
     Embodiments the second aspect of the present invention may include one or more features of the first aspect of the present invention or their embodiments. 
     According to a third aspect of the present invention there is provided 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 link members for connecting adjacent track plate links together, each 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.   
               

     Each track plate may be associated with four link members. Each track plate link may be associated with two link members. 
     Each link member may be moveably connected to the track plate link. Each link member may be connected to the track plate link such that the link member may pivot or rotate relative to the track plate link. 
     Each track plate link may include a pin member engaging portion. Each pin member engaging portion may be a hook or loop. Each pin member engaging portion may be hook shaped. Each hook or loop of the pin member engaging portion may include a generally U-shaped channel for receiving the pin member therein. Each hook or loop of the pin member engaging portion may include an elongate U-shaped channel portion. 
     Each pin member engaging portion may be configured such that, in use, the pin member of the link member is received therein and moves with respect thereto. 
     Each track plate link may be a longitudinal member having a lateral cross section that is C-shaped. Each track plate link may be a longitudinal member having a lateral cross section that is generally C-shaped. 
     Each track plate link may be around 20 mm thick. Each track plate link may be between 10 mm and 40 mm thick. 
     Each pin member engaging portion may be provided in the lower or upper portion of the track plate link. Pin member engaging portions may be provided in the lower and upper portions of the track plate link. The pin member engaging portions may be located at opposite ends of the track plate link. Each track plate link may include two pin member engaging portions, such that two link members may be connected thereto. 
     Each link member may have a longitudinal axis and a lateral axis. Each link member may be symmetrical along the longitudinal and/or lateral axes. Alternatively, each link member may be symmetrical along the lateral axis and non-symmetrical along the longitudinal axis. Haggis/non-Haggis flanges 
     Each link member may be formed as a single piece, or single component. Each link member may be forged. Each link member may be a forged member. Each link member may be forged from steel. The steel may be a boron alloy steel. 
     The side members and the pin members may be arranged such that each link member is substantially square shaped in plan view. 
     Each link member may be between 40 mm and 250 mm long. Each link member may be around 123 mm long. Each link member may be between 115 mm and 130 mm long. Each link member may be around 115 mm long. 
     Each link member may be between 50 mm and 120 mm wide. Each link member may be around 90 mm wide. Each link member may be between 85 mm and 90 mm wide. 
     Each link member may be between 25 mm and 55 mm tall. Each link member may be around 48 mm tall. Each link member may be between 45 mm and 55 mm tall. 
     The side members may be substantially elongate planar members. Each side member may have a longitudinal axis. 
     The side members may be arranged to be parallel to one another. 
     The side members may be arranged to be substantially perpendicular to the pin members. 
     The side members may be identical. Alternatively, one side member may have a different length, width and/or height that the other side member. Each side member may have differently shaped outwardly facing surface. 
     The side members may have curved outwardly facing surface. At least a portion of the outwardly facing surface of the side member may be at least partially spherical in shape. One or more portions of the outwardly facing surface of the side members may be at least partially spherical in shape. 
     The side members may have substantially planar inwardly facing surfaces. The planes of the surfaces of the two side members may be parallel. 
     The side members may have bulbous portions or lobe portions located at each end thereof. 
     The outwardly facing surfaces and/or the inwardly facing surfaces of the side members may be smooth. 
     The side members may be between 40 mm and 250 mm long. The side members may be around 123 mm long. The side members may be around 121 mm long. The side members may be between 115 mm and 130 mm long. 
     One side member may be an inner side member and the other side member may be an outer side member. The outer side member may be longer than the inner side member. The outer side member may be taller than the inner side member. The outer side member may be thicker than the inner side member. 
     The inner side member may be between 40 mm and 250 mm long. The inner side member may be around 121 mm long. The inner side member may be between 115 mm and 127 mm long. 
     The inner side member may be between 25 mm and 55 mm tall. The inner side member may be around 40 mm tall. The inner side member may be between 35 mm and 45 mm tall. 
     The outer side member may be between 40 mm and 250 mm long. The outer side member may be around 123 mm long. The outer side member may be between 115 mm and 130 mm long. 
     The outer side member may be between 25 mm and 55 mm tall. The outer side member may be around 48 mm tall. The outer side member may be between 45 mm and 55 mm tall. 
     The distance between the inwardly facing surfaces of the side members may be between 40 mm and 100 mm. The distance between the inwardly facing surfaces of the side members may be around 52.5 mm. The distance between the inwardly facing surfaces the side members may be between 50 mm and 55 mm. 
     The side members may have a height that is greater than the height, thickness, or width of the pin members. 
     At least one side member may include a flange surface. The flange surface may circumscribe an inwardly facing surface of the side member. Both side members may include a flange surface. Both flange surfaces may circumscribe an inwardly facing surface of the side member. The flange surface of the second side member may be larger than the flange surface of the first side member. 
     The lateral cross section of each pin member may be substantially the same shape along the entire length of the pin member. 
     The pin members may be substantially elongate members. Each pin member may have a longitudinal axis. 
     The pin members may be substantially parallel to one another. 
     The pin members may be arranged to be substantially perpendicular to the side members. 
     The pin members may be identical. Alternatively, the pin members may be differently shaped. 
     The outer surface of the pin members may be smooth. 
     The distance between the inwardly facing surfaces of the pin members may be between 40 mm and 160 mm. The distance between the inwardly facing surfaces of the pin members may be around 58 mm. The distance between the inwardly facing surfaces the pin members may be between 55 mm and 65 mm. 
     The pin members may be between 40 mm and 100 mm long. The pin members may be around 52.5 mm long. The pin members may be between 45 mm and 60 mm long. 
     The pin members may be arranged such that they join the side members at a location which is between the lowest portion and highest portion of the side member. 
     The axis of symmetry of the lateral cross section of each pin member may be perpendicular to the longitudinal axis of the pin member. 
     The axis of symmetry of the lateral cross section of each pin member may be parallel to the longitudinal axis of each side member. 
     The axes of symmetry of the lateral cross sections of the pin members may be parallel. 
     The lateral cross section of each pin member may be ovate in shape. The lateral cross section of each pin member may be ovate shaped. The lateral cross section of each pin member may be generally ovate in shape. The lateral cross section of each pin member may be generally ovate shaped. 
     The lateral cross section of each pin member may have a shape that resembles the longitudinal section of an ovoid. The lateral cross section of each pin member may have a shape that is generally like the longitudinal section of an ovoid. The lateral cross section of each pin member may be the shape of the longitudinal section of an ovoid. The lateral cross section of each pin member may substantially be the shape of the longitudinal section of an ovoid. 
     The pin members may be in the shape of extended ovates. 
     The lateral cross section of each pin member includes a longitudinal axis and a lateral axis. The longitudinal axis is aligned with the axis of symmetry. The longitudinal axis is parallel to the axis of symmetry. 
     The lateral cross section may have 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 may be greater than the width of the lateral cross section. 
     The lateral cross section of each pin member may have a first portion and a second portion. The first portion may be partially circular in shape. The second portion may be partially circular in shape. The first portion may have a first radius. The second portion may have a second radius. The first radius may be greater that the second radius. The pin member may thus have a partially cylindrical first portion and a partially cylindrical second portion. 
     The first radius of the first portion may be between 8 mm and 20 mm. The first radius of the first portion may be around 15 mm. The first radius of the first portion may be between 12.5 mm and 17.5 mm. 
     The second radius of the second portion may be between 8 mm and 20 mm. The second radius of the second portion may be around 12.2 mm. The second radius of the second portion may be between 12.5 mm and 17.5 mm. 
     The first portions of the lateral cross sections of each pin member may be arranged to face each other. 
     The first portions of the lateral cross sections of each pin member may face inwards and the second portions of the lateral cross sections of each pin member may face outwards. 
     The centre of the partial circle of the first portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle of the second portion of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centres of the partial circles of the first and second portions of the lateral cross section may lie on the axis of symmetry of the lateral cross section. The centre of the partial circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the partial circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The centre of the circle defined by the radius of the first portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the second portion may lie on the axis of symmetry of the lateral cross section. The centre of the circle defined by the radius of the first portion may lie outside the circle defined by the radius of the second portion. Similarly, the centre of the circle defined by the radius of the second portion may lie outside the circle defined by the radius of the first portion. 
     The lateral cross section may have a maximum length of around 31.5 mm. The maximum length of the lateral cross section may be between 16 mm and 40 mm. The maximum length of the lateral cross section may be between 25 mm and 35 mm. 
     The pin members may have a maximum width of around 31.5 mm. The maximum width of the pin members may be between 16 mm and 40 mm. The maximum width of the pin members may be between 25 mm and 35 mm. 
     The lateral cross section may have a maximum height of around 27 mm. The maximum height of the lateral cross section may be between 16 mm and 40 mm. The maximum height of the lateral cross section may be between 22 mm and 32 mm. 
     The pin members may have a maximum height of around 27 mm. The maximum height of the pin members may be between 16 mm and 40 mm. The maximum height of the pin members may be between 25 mm and 35 mm. 
     The line joining the points where the length of the lateral cross section is at its maximum may be aligned with the axis of symmetry of the lateral cross section. The line joining the points where the height of the lateral cross section is at its maximum may be perpendicular to the axis of symmetry of the lateral cross section. The point where the line joining the points where the length of the lateral cross section is at its maximum and the line joining the points where the height of the lateral cross section is at its maximum intersect may be the centre point of the lateral cross section. This may be the centre point of each pin member. 
     The distance between the centre points of each lateral cross section of each pin member may be between 40 mm and 200 mm. The distance between the centre points of each lateral cross section of each pin member may be around 75 mm. The distance between the centre points of each lateral cross section of each pin member may be around 85 mm. The distance between the centre points of each lateral cross section of each pin member may be between 75 mm and 85 mm. 
     Each pin member may include a track plate link engaging portion. The track plate link engaging portion may be located on the inner surface, or inwardly facing surface, of the pin member. The track plate link engaging portions may be arranged such that they face one another. The track plate link engaging portions may have a partially cylindrical surface. 
     The track plate link engaging portion may be complementary in shape to the pin member engaging portion of the track plate link. The track plate link engaging portion may be at least partially complementary in shape to the pin member engaging portion of the track plate link. The track plate link engaging portion may have a portion that is at least partially complementary in shape with a portion of the pin member engaging portion of the track plate link. 
     The pin member engaging portion of the track plate link may have a concave portion. The concave portion may have a partially cylindrical surface. 
     The pin member engaging portion of each track plate link may include a longitudinal channel portion. At least a portion of the longitudinal channel portion may be at least partially complementary in shape with a portion of the track plate link engaging portion of each pin member. At least a portion of the longitudinal channel portion may be concave. The concave portion may have a partially cylindrical surface. 
     At least a portion of the pin member engaging portion of each track plate link may be complementary in shape to at least a portion of the first portion of each pin member. 
     The radius of the concave portion of the longitudinal channel may be substantially the same as the radius of the first portion of the lateral cross section of the pin member. 
     The at least a portion of the pin member engaging portion may have a partially cylindrical surface, the radius of which is substantially the same as the radius of the first portion of the lateral cross section of each pin member. 
     The radius of the concave portion of the longitudinal channel may have a radius between 8 mm and 20 mm. The radius of the concave portion of the longitudinal channel may be around 15 mm. The radius of the concave portion of the longitudinal channel may be between 12.5 mm and 17.5 mm. 
     Each pin member and each track plate link may be configured such that there is approximately a 90° contact area between the track plate link engaging portion and the pin member engaging portion, measured from the centre point of radius engaging face of the pin member. Each pin member and each track plate link may be 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 centre point of radius engaging face of the pin member. 
     Each track plate may comprise two track plate links. Each track plate link may be located at opposite ends of the track plate. Each track plate link may include two pin member engaging portions. The pin member engaging portions may be located at opposite ends of the track plate link. 
     In use, the link member may connect to adjacent track plate links. That is, a first pin member of a link member may be connected with a pin member engaging portion of a first track plate link and a second pin member of the link member may be connected with a pin member engaging portion of a second track plate link. 
     The track plate may include one or more track paws. Each track paw may be connected to the track plate links. The track paws being configured to at least partially house a wheel of a wheel vehicle when in use. The track plate may include a track paw at each end of the track plate. The track paws may be configured such that the oppose one another. 
     Embodiments the third aspect of the present invention may include one or more features of the first or second aspects of the present invention or their embodiments. 
     According to a fourth aspect of the present invention there is provided 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 an ovate lateral cross section.       

     The term ovate used throughout this specification is considered to mean a shape that is the shape of the longitudinal section of an ovoid, or is generally the same shape as the longitudinal section of an ovoid. 
     Embodiments the fourth aspect of the present invention may include one or more features of the first, second or third aspects of the present invention or their embodiments. 
     According to a fifth aspect of the present invention there is provided 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 an ovate lateral cross section.   
               

     Embodiments the fifth aspect of the present invention may include one or more features of the first, second, third or fourth aspects of the present invention or their embodiments. 
     According to a sixth aspect of the present invention there is provided 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 link members for connecting adjacent track plate links together, each 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 an ovate lateral cross section.   
               

     Embodiments the sixth aspect of the present invention may include one or more features of the first, second, third, fourth or fifth aspects of the present invention or their embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiment of the present invention will now be described, by way of example, with reference to the drawings, in which: 
         FIG. 1  is a perspective view of a continuous track system according to the present invention; 
         FIG. 2  is a schematic side view of the track system of  FIG. 1 ; 
         FIG. 3  is a partial side view of the track system of  FIG. 1 ; 
         FIG. 4 a    is side view of a track plate according to the present invention; 
         FIG. 4 b    is a plan view of two joined track plates of  FIG. 4   a;    
         FIG. 5 a    is a perspective view of a link member according to the present invention; 
         FIG. 5 b    is a plan view of the link member of  FIG. 5   a;    
         FIG. 5 c    is a side view of the link member of  FIG. 5   a;    
         FIG. 5 d    is a cross sectional view along section A-A of  FIG. 5   b;    
         FIG. 5 e    is a cross sectional end along section B-B of  FIG. 5   b;    
         FIG. 5 f    is an end view of the link member of  FIG. 5   a;  and 
         FIG. 6  is a schematic in use side view of the link member of  FIG. 5   a.    
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 to 4   b  a continuous track system  10  is illustrated. In the embodiment illustrated and described here the track system  10  is fitted to two-wheels  10   a  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. 
     The track system  10  is made up of a number of track plates  10   b,  track plate links  10   c,  track paws  10   d  and link members  12 . 
     The track plates  10   b  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  10   f  (anti-skid spikes). 
     As best illustrated in  FIGS. 3, 4   a  and  4   b,  each track plate  10   b  includes two track plate links  10   c,  each track plate link  10   c  being attached at an end portion  10   g  of the track plate  10   b.  The track plate links  10   c  are typically welded to the track plate  10   b.    
     The track paws  10   d  are used to retain the wheels  10   a  within the track system  10  when in use. As best illustrated in  FIGS. 3, 4   a  and  4   b,  each track plate  10   b  includes two track paws  10   d,  each track paw  10   d  being attached at an end portion  10   g  of the track plate  10   b.  The track paws  10   d  are also attached to the track plate link  10   c.  The track paws  10   d  are typically welded to the track plate  10   b  and the track plate link  10   c.  The track paws  10   d  are typically welded to the track plate link  10   c  in a gap between two pin member engaging portions  10   i.    
     The link members  12  are used to connect adjacent track plates  10   b  together. The link members  12  achieve this by engaging with the track plate links  10   c.  Each track plate  10   b  is associated with four link members  12 , each track plate link  10   c  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  10   c  such that the link member  12  can pivot or rotate relative to the track plate  10   b  and track plate link  10   c.    
     The link member  12  forms part of the present invention and is illustrated in more detail in  FIGS. 5 a    to  5   f.    
     The link member  12  comprises two side members, or flanges,  12   a  and two pin members  12   b.  As best illustrated in  FIG. 5   b,  the link member  12  is arranged such that the two side members  12   a  oppose each other and are joined together by the two pin members  12   b.    
     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 . 
     As best illustrated in  FIG. 5   b,  the side members  12   a  and the pin members  12   b  are arranged such that the link member  12  is substantially square shaped in plan view. Here the side members  12   a  are arranged to be substantially perpendicular to the pin members  12   b.  The link member  12  has a longitudinal axis  12   c  and a lateral axis  12   d.  In the embodiment illustrated and described here the link member  12  is symmetrical along the lateral axis  12   d.  The link member  12  may also be symmetrical along the longitudinal axis  12   c.  Where the link member  12  is symmetrical along the longitudinal axis  12   c,  the side members  12   a  would be identical. 
     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. 
     As best illustrated in  FIGS. 5 a    and  5   b,  the side members  12   a  are substantially elongate planar members and are arranged to be parallel to one another. Each side member  12   a  includes a longitudinal axis  12   e.    
     The link member  12  includes a first side member  12   a ′ and a second side member  12   a ″. The first side member  12   a ′ may be an inner side member and the second side member  12   a ″ may be an outer side member. The first side member  12   a ′ is arranged to be closer to the tyre  10   a ′ that the second side member  12   a″.    
     In the embodiment illustrated and described here the first side member  12   a ′ and the second side member  12   a ″ are non-identical, as described further below. However, it should be appreciated that the first side member  12   a ′ and the second side member  12   a ″ may be identical. 
     As best illustrated in  FIGS. 5   b,    5   e  and  5   f,  each side member  12   a  may have a curved outwardly facing surface  12   f  and a substantially planar inwardly facing surface  12   g.  Each curved outwardly facing surface  12   f  may have one or more portions that are partially spherical in shape. The planes of the planar inwardly facing surfaces  12   g  are substantially parallel. The curved outwardly facing surfaces  12   f  and the planar inwardly facing surfaces  12   g  are smooth to prevent excessive wear on the tyre  10   a ′ of the wheel  10   a.  It should be appreciated that the inwardly facing surfaces  12   g  may not be exactly planar and may have a low apex that runs parallel to the longitudinal axis thereof. That is, inwardly facing surfaces  12   g  may have a 6° draft angle. The draft angle may also be between 3° and 9°. This is a result of the forging process. 
     With reference to  FIGS. 5   a,    5   c  and  5   d,  the side members  12   a  have bulbous portions, or lobes  12   h,  located at each end thereof. 
     As best illustrated in  FIGS. 5   a,    5   e  and  5   f,  the second side member  12   a ″ has different dimensions compared to the first side member  12   a ′. In the embodiment illustrated and described here the second side member  12   a ″ is taller than the first side member  12   a ′. The second side member  12   a ″ has a height of 48.0 mm, compared to a height of 40.0 mm of the first side member  12   a ′. 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  10   c.  That is, the larger outer side member has a greater area of contact with the track plate link  10   c,  which prevents the link member  12  from twisting. Preventing the link member  12  from twisting ensures that the only the pin members  12   b  of the link member  12  engage with the track plate link  10   c  and not any other part of the link member  12 , i.e. that the link runs true throughout its life. 
     In the embodiment illustrated and described here the first side member  12   a ′ is 121.0 mm long and the second side member  12   a ″ is 123.3 mm long. 
     The distance between the inwardly facing surfaces  12   g  of the side members  12   a  are 52.5 mm. 
     As illustrated in  FIGS. 5 e    and  5   f,  the side members  12   a  have a height that is greater than the thickness, or width, of the pin members  12   b.    
     However, it should be appreciated that the dimensions of the side members  12   a  may be configured or altered to suit requirements of use of the link member  12  and the track system  10 . 
     As best illustrated in  FIGS. 5   b,    5   e  and  5   f,  the pin members  12   b  are longitudinal, or elongate, members having a longitudinal axis  12   i.  The pin members  12   b  are arranged to be substantially parallel to one another and substantially perpendicular to the side members  12   a.    
     As best illustrated in  FIGS. 5 e    and  5   f,  the pin members  12   b  are arranged such that they join the side members  12   a  at a location which is between the lowest portion and the highest portion of the side member  12   a.  The effect of this is that it allows the side members  12   a  to be flanges, with shoulder portions  12   l.  The shoulder portions  12   l  create a flange surface  12   m  which circumscribes the inwardly facing surface  12   g  of each side member  12   a.  In use, the flange surfaces  12   m  may contact the track plate link  10   c  and limit the lateral movement thereof. The flange surfaces  12   m  also prevent twisting of the link members  12   a  when in use. The flange surface  12   m  of the second side member  12   a ″ is larger than the flange surface  12  of the first side member  12   a′.    
     As best illustrated in  FIG. 5   d,  the pin members  12   b  have a lateral cross section  12   j.  The lateral cross section  12   j  has a single axis of symmetry  12   k.  As best illustrated in  FIGS. 5 d    and  5   e,  the axis of symmetry  12   k  of the lateral cross section  12   j  of each pin member  12   b  is perpendicular to the longitudinal axis  12   i  of the pin member  12   b  and parallel to the longitudinal axis  12   c  of the side members  12   a.  The axes of symmetry  12   k  of the lateral cross sections  12   j  of each pin member  12   b  are also parallel. 
     In the embodiment illustrated and described here, and as best illustrated in  FIG. 5   d,  the lateral cross section  12   j  of each pin member  12   b  is generally ovate in shape. That is, the lateral cross section  12   j  of each pin member  12   b  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  12   j  of each pin member  12   b  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. 
     The lateral cross section  12   j  of each pin member  12   b  is substantially the same shape along the entire length of the pin member  12   b.  The pin members  12   b  are therefore in the shape of extended ovates. Furthermore, the pin members  12   b  are substantially identical in shape. 
     Again as best illustrated in  FIG. 5   d,  the lateral cross section  12   j  has a longitudinal axis  12   n,  which is aligned with the axis of symmetry  12   k,  and a lateral axis  12   o  that is perpendicular to the longitudinal axis  12   n.  The lateral cross section  12   j  has a length in the direction of the longitudinal axis  12   n  and a width in the direction of the lateral axis  12   o.  The length of the lateral cross section  12   j  is greater than the width of the lateral cross section  12   j.  The maximum length of the lateral cross section  12   j  is greater than the maximum width of the lateral cross section  12   j.    
     The lateral cross section  12   j  of each pin member  12   b  has a first portion  12   p  and a second portion  12   q.  The first and second portions  12   p  and  12   q  are partially circular in shape. The partial circle of the first portion  12   p  has a first radius  12   p ′ and the partial circle of the second portion  12   q  has a second radius  12   q ′, the first radius  12   p ′ being larger than the second radius  12   q ′. The first radius  12   p ′ may be 15 mm and the second radius  12   q ′ 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  12   b  may thus have a partially cylindrical first portion  13  and a partially cylindrical second portion  15 . 
     The centre  12   r  of the circle defined by the radius  12   p ′ of the first portion  12   p  lies on the axis of symmetry  12   k  of the lateral cross section  12   j.  The centre  12   s  of the circle defined by the radius  12   q ′ of the second portion  12   q  lies on the axis of symmetry  12   k  of the lateral cross section  12   j.  The centre  12   r  of the circle defined by the radius  12   p ′ of the first portion  12   p  lies outside the circle defined by the radius  12   q ′ of the second portion  12   q.  Similarly, the centre  12   s  of the circle defined by the radius  12   q ′ of the second portion  12   q  lies outside the circle defined by the radius  12   p ′ of the first portion  12   p.    
     In the embodiment illustrated and described here the lateral cross section  12   j  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 . 
     Furthermore, the line joining the points where the length of the lateral cross section  12   j  is at its maximum is aligned with the axis of symmetry  12   k  of the lateral cross section  12   j  and the line joining the points where the width of the lateral cross section  12   j  is at its maximum is perpendicular to the axis of symmetry  12   k  of the lateral cross section  12   j.  The point where the line joining the points where the length of the lateral cross section  12   j  is at its maximum and the line joining the points where the width of the lateral cross section  12   j  is at its maximum intersect may be the centre point  12   t  of the lateral cross section  12   j.  This may be the centre point of each pin member  12   b.  The distance between centre points  12   t  of each pin member is 85 mm. 
     The distance between the inwardly facing surfaces  12   g  of the pin members  12   b  is 58 mm. Furthermore, the pin members  12   b  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 . 
     As best illustrated in  FIG. 5   d,  the first portions  12   p  of the pin members  12   b  are arranged to face each other. That is, the first portions  12   p  of the pin members  12   b  face inwards and the second portions  12   q  of the pin members  12   b  face outwards. 
     With reference to  FIG. 6  the link member  12  is illustrated schematically in use with a track plate link  10   c.  It should be appreciated that only the lateral cross sections  12   j  of the pin members  12   b  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  10   c  to allow respective movement between each link member  12  and each track plate link  10   c.    
     As illustrated, the track plate link  10   c  is a longitudinal member having a lateral cross section  10   h  that is C-shaped. The thickness of each track plate link  10   c  is 20 mm. 
     Each track plate link  10   c  includes a pin member engaging portion  10   i.  The pin member engaging portion  10   i  is an elongate U-shaped channel portion. As illustrated, the pin member engaging portions  10   i  are located at opposite ends of the track plate link  10   c.  Therefore, each track plate link  10   c  includes two pin member engaging portions  10   i.    
     The pin member engaging portions  10   i  are thus concave with a partially cylindrical surface  17 . The radius of the partially cylindrical surface  17  is configured to substantially match the radius  12   p ′ of the first portion  12   p  of the lateral cross section  12   j  and partially cylindrical first portion  13  of the pin member  12   b.  The partially cylindrical surface  17  of the pin member engaging portions  10   h  is thus complimentary in shape to the partially cylindrical first portion  13  of the pin members  12   b.    
     The partially cylindrical first portion  13  of each pin member  12   b  includes track plate link engaging portions  12   u.  The track plate link engaging portions  12   u  thus face the pin member engaging portions  10   i.    
     The track plate link engaging portions  12   u  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  10   i.  The track plate link engaging portions  12   u  are thus complementary in shape to the pin member engaging portions  10   i  of the track plate link  10   c.    
     The radius of the partially cylindrical surface  17  of the pin member engaging portions  10   i  is 15 mm and the radius of the partially cylindrical surface  19  of the track plate link engaging portions  12   u  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 . 
     Each pin member  12   b  and each track plate link  10   c  are configured such that there is approximately a 90° contact area between the track plate link engaging portion  12   u  and the pin member engaging portion  10   i,  measured from the centre point  12   t  of the pin member  12   b.    
     As illustrated in  FIG. 6 , the link members  12   b  connect adjacent track plate links  10   c  together. That is, a first pin member  12   b  of a link member  12  is connected with a pin member engaging portion  10   i  of a first track plate link  10   c  and a second pin member  12   b  of the link member  12  is connected with a pin member engaging portion  10   i  of a second track plate link  10   c.    
     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. 
     Providing a link member  12  having pin members  12   b  having a lateral cross section  12   j  as described above ensures that the track plate link engaging portions  12   u,  and the pin members  12   b,  are complimentary in shape to the pin member engaging portions  10   i  of the track pate links  10   c.    
     In the embodiment illustrated and described here the radius of the partially cylindrical surface  19  of the track plate link engaging portions  12   u  of the pin members  12   b  are configured to match the radius of the partially cylindrical surface  17  of the pin member engaging portions  10   i  of the track plate links  10   c.  Matching the radii almost eliminates the bedding in period and results in less frequent re-tensioning. 
     The present invention also provides an increased contact area between the track plate link engaging portion  12   u  and the pin member engaging portion  10   i.  Increasing this contact area also reduces the high initial wear period, which results in a longer life of the component. 
     Furthermore, providing a link member  12  whereby the length of the lateral cross section  12   j  is greater than the width of the lateral cross section  12   j  maximises material across the critical wear point of the link member  12 , which increases the lifespan of the member. 
     Providing a link member  12 , a track plate  10   b  and a continuous track system  10  according to the present invention reduces the amount of re-tensioning required. 
     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  12   j  has been illustrated and described above as being generally ovate in shape, it should be appreciated that the lateral cross section  12   j  may have other shapes. Similarly, although the lateral cross section  12   j  has been illustrated and described above as having a single axis of symmetry  12   k,  it should be appreciated that the lateral cross section  12   k  may not necessarily have only one axis of symmetry. 
     Furthermore, although the link member  12  has been illustrated and described above as having a first side member  12   a ′ and a second side member  12   a ″, the first and second side members  12   a ′ and  12   a ″ having different dimensions, it should be appreciated that the first and second side members  12   a ′ and  12   a ″ may be identical.