Patent GB-306431-A (GB)
Title: Improvements in endless tracks for vehicles
IPC: B62D55/096
Filed: 1927-11-11
Abstract: 306,431. Roadless Traction, Ltd., and Penn, O. S. Nov. 11, 1927. Addition to 248,839. Endless-track vehicles.-Relates to endlesstracks of the kind described in the parent Specification in which no strain due to downward pressure is carried by the joint pins, and comprises the following features : (1) the track link is provided with additional abutments or lugs having locking faces 20, 21, Figs. 9-12, arranged in vertical or substantially vertical planes, these faces relieving the joint pins of horizontal stress. The vertical stress is taken, as in the parent Specification, by horizontal abutments 6, 7. All the links are alike, the abutments 21, Fig. 9, being formed on one side of each link, and the abutments 20 on the. bent lugs 19, Fig. 10, on the other side, the track being assembled by reversing alternate links so that each abutment 21 mates with an abutment 20. The base or shoe portion 1 of each link is formed with wedge-shaped horizontal abutments 22 and recesses 24 which mate with corresponding parts on the adjoining links and take horizontal and lateral thrusts and also tend to centre each link relatively to the next. (2) The links are connected together by joint pins 10 which are a clearance fit in one of the two holes of adjacent side plates of the links and a press fit in the other. The clearance thus formed in the joint allows the links, when in the horizontal or locking position, to adjust themselves to any inaccuracy of the locking faces. (3) The link is formed or pressed from a single sheet of material, and comprises a base portion 1 having upstanding sides 2 in which are formed the holes for the connecting pins or studs, and abutments 7 at each end of the side plates adapted to engage with central abutments 6 on the side plates of adjacent links. The link may be formed by-(a) blanking out the metal in I form, (b) punching out from the blank portions in the ends of the I to form the end abutments and the holes for the connecting pins, (c) bending back the ends of the I to form the side plates, and (d) stamping out portions of the side plates to form lugs standing out at right angles and acting as the central abutments. The end abutments may be formed in operation (a) instead of in (b). The additional or vertical abutments may be formed during operation (b). (4) The surface 36, Fig. 17, forming the roller path of each link is raised to a plane only slightly below that passing through the axes of the joint pins. The surface 36 may comprise a metal plate riveted to the link, or a block of wood may be used. (5) The links are formed with abutments having spherical engaging surfaces 33, 35, Figs. 14, 15. which take vertical and horizontal stresses. Each side plate 31 is formed with two convex spherical faces 33 and two concave surfaces 35, arranged in two offset planes so that the surfaces 33 on one link engage the surfaces 35 on adjoining links. The roller path 29 is -raised relatively to the base plate 28 so as to be only slightly lower than the joint pin. (6) The invention may be applied to a barrow as shown in Fig. 7, the track 16 passing over rollers 15 mounted on the ends of bars 14 pivoted to brackets 12 on the frame 13. The line 17' indicates the outline of a wheel giving an equivalent effect to that obtained by the use of the track.