Patent GB-423445-A (GB)
Title: Improvements in or relating to endless track apparatus for vehicles
IPC: B62D55/28
Filed: 1933-08-01
Abstract: 423,445. Endless-track vehicles. BARTLETT, B. G. W., 1, Cartmell Terrace, Brinkburn Road, Darlington. Aug. 1, 1933, 21614. [Class 79 (i)] Endless-track apparatus of the kind wherein one or more elongated members disposec on each side of the vehicle is associated with one or more endless series of rolling members and an outer endless flexible road-engaging track or tracks, the vehicle being resiliently mounted on the elongated members, is characterized in that each elongated member is pivoted medially of its ends on a spindle or spindles whereon the vehicle is resiliently mounted. In the construction shown in Figs. 1-3, each side of the vehicle is provided with an elongated member 1 pivoted on an axle 2 resiliently connected to the body of the vehicle. The member 1 is further connected to the vehicle by pairs of springs 7 connected by links 11 to pins 10 on the member and having their centres disposed in boxes 8 secured or pivoted to pins 4 secured to the side of the vehicle. Other pins 5 also secured to the vehicle are connected to the pins 4 by links 9. The axle 2 is connected to the vehicle frame by axle-boxes 12, springs 13 and links 14. The axles 2 at each side of the vehicle may be connected together by a straight rigid axle 39 or a cranked axle 42 which may be resilient, or each axle may be formed with an arm 40 sliding in brackets 41 in the frame. A flexible endless band or bands 20 of leather, rubber, or other resilient material, preferably faced with metal on one or both sides, passes round the member 1, the upper part of the band being supported by and secured to a spring 19 secured to a spring 18 fixed to the axle 2 or the member 1. The lower part of the member 1 is formed as a housing 15 enclosing resilient members 16 which may comprise pneumatic cushions of rubber or leather. The lower part of the housing 15 is closed by the endless band 20. An endless chain of rollers 26 connected together by links 29 runs round the member 1 on the surface of the band 20, and one or more endless bands 30 of steel, rubber, leather or other flexible or resilient material passes round the rollers 26. A ground-engaging endless track 32 runs over the upper and lower runs of the bands 30 and over driving or idler sprockets 33. The member 1 is formed with a central downwardly-extending rib or ribs 24 engaging a groove or grooves 27 in the rollers 26 so as to prevent side play of the latter. Similarly, the band 30 is formed with a central strip or rib 31 to engage the groove 27 and keep the band in place, and the links 34 of the track 32 are formed with lugs 35 projecting on either side of the band 30 and engaging grooves in the rollers 26. The track links may be formed with lugs 36 to form a channel for a flexible endless band 37 of steel, leather, rubber or other material, preferably projecting beyond the lugs 36 to engage the road surface. The band 37 may be grooved between each track link to increase its flexibility. The track links 34 may be cast and may be drilled or grooved for lightness. Each driving sprocket 33 may comprise a pair of plates connected together by pins to form a lantern wheel, the pins engaging transverse grooves in the track links 34. The vehicle may be braked by means of a roller which is controlled by a brake and may be lowered to engage the ground either by hand or automatically on a gradient. The following modifications are described : (1) In Figs. 6 and 7 (not shown), the resilient members 16 comprise either a number of solid or airfilled rubber balls, or layers of corrugated resilient metal sheets interleaved with flat metallic sheets, the housing 15 being lined with rubber or leather. (2) In Fig. 8 (not shown), the rollers 26 are connected together by endless metal strips looped round the roller spindles and formed with loops between the spindles. (3) In Figs. 11-13 and 17-19 (not shown), the elongated member 1 is formed in two parts hinged together on the axle 2, separate resilient members 16 being formed in each part of the member 1. The two parts of the member 1 may be resiliently connected together. (4) In Figs. 14 and 15 (not shown), the axles 2 may be connected to the vehicle by sliding trunnions and rubber or leather cushions which permit transverse compensating action. (5) In Figs. 20 and 21 (not shown), the rollers 26 are guided laterally on the member 1 by means of a laminated spring which engages a central groove in the rollers and is fixed to a series of rings which can move vertically but not laterally in the member 1. (6) In Figs. 24 and 25 (not shown), the rollers 26 are in two series, staggered relatively to each other ; and (7) In Figs. 26 and 27 (not shown), the rollers 26 are arranged in groups or bogies of four rollers, each group being connected to the next by a central link.