GB1448805A - Tricycle - Google Patents

Abstract

1448805 Tricycles SUZUKI MOTOR CO Ltd 5 Aug 1974 34450/74 Heading B7E A tricycle comprises a front wheel 1 rotatably carried by a front fork 2, a main frame 3 steerably mounting the front fork, an axle frame 6 rotatably mounting two rear wheels 4, 5 at respective ends thereof, means 13 at the rear end of the frame 3 supporting a driven shaft 15 carrying a driven sprocket 16, a support secured to the rear part of the frame 3 supporting the frame 6 at its centre such that the frames 3, 6 are pivotable relative to one another, and resilient means, e.g. 9, for damping or restoring pivotal movement of the frames 3, 6, the shaft 15 being connected to the axle of at least one rear wheel through a universal or flexible joint, e.g. 21, and the pivot axis of the frames 3, 6 passing through the centre of the joint. In the illustrated embodiments the frames 3, 6 are pivoted such that in use a rider can lean and incline the frame 3 to the vertical on negotiating a bend and the frame 6 will pivot relative to the frame 3 to take up shocks on travelling over rough ground, the universal or flexible joint enabling the drive transmission to the rear wheel or wheels to accommodate relative pivotal movement of the frames 3, 6. In the embodiment of Figs. 1 and 4 a shaft 7 at the centre of the frame 6 passes through a pivot bearing 8 at the rear of the frame 3 to terminate in a square section end 12 received between four rubber blocks 11 of a Neidhart type rubber spring mechanism 9 on the frame 3. The shaft 15 is connected through a universal joint 21 directly to the axle of the rear wheel 5, (Fig. 3, not shown), and the sprocket 16 is driven through a chain 17 from a pedal drivensprocket 18. The Figs. 1 and 4 embodiment may be modified by making the shaft 7 extend directly forwardly from the frame 6 into the bearing 8 and mechanism 9, Fig. 5, in which case the shaft 15 is connected through the joint 21 to shaft 20 supported in a bearing 23 on the frame 6 and carrying a sprocket 24 connected by a chain 27 to a sprocket 25 on the axle of the rear wheel 5. In a further modification of the Figs. 1 and 4 embodiment (Fig. 6, not shown), the shaft 15 is connected through the joint 21 to a shaft supported on the frame 6 which in turn is connected through a sprocket and chain arrangement and a differential gear to a common axle mounting the wheels 4, 5 such that both rear wheels are driven. The universal joint 21 may be replaced by a flexible joint comprising a helical coil of spring steel wire (Fig. 8, not shown), and the Neidhart mechanism 9 may be replaced by a spring 38 as shown in Fig. 9 or by a cylindrical rubber torsion spring in which the shaft 7 is embedded (Fig. 10, not shown).