GB667667A - Improvements in steering of vehicles having three axles - Google Patents

Abstract

667,667. Steering motor vehicles or trailers. OFFICINE VIBERTI SOC. PER AZIONI. July 26, 1948 [July 25, 1947], No. 19941/48. Classes 79(iii) and 79(v) in a steering device for a three-axled vehicle the wheels of the third axle are mounted on stub axles carrying steering arms, which are interconnected by a track rod, and the track rod is provided with a centralizing spring device having means for adjusting the alignment of such wheels and for adjusting the initial load of the spring device, the stub axles turning automatically when the vehicle is cornering due to the reaction between the wheels and the ground. As shown, the invention is applied to a trailer 2 drawn by a tractor 1 both having steerable front wheels. The rear axle 4 of the trailer, Fig. 3, has pivoted at 20 stub axles carrying the wheels 3, the wheels being mounted in pairs, the outer one of each pair being rotatably mounted relative to the inner wheel, the steering arms 6 of which are each pivotally connected to a sleeve 12. The sleeves 12 are threadedly engaged with the track rod 7 carrying a spring 8 which at each end abuts a slidable sleeve 22. Shown abutting a flange on each sleeve is another sleeve 9 held in position relative to the axle 4 by a rod 10. In operation the wheels 3 are steered by the movement of the wheels about the pivots 20 due to ground reaction, and the spring 8 urges the wheels back to their fore-andaft position. As the ground reaction will vary. with the trailer load the effect of the spring 8 can be varied therewith either manually, Figs. 5 and 8, or automatically, Fig. 4. In the variations shown in Figs. 5 and 8 the spring is formed in two parts. In Fig. 5 the parts bear against slidable sleeves 14, 14<SP>1</SP> in the middle portion of the axle, the sleeves 14, 14<SP>1</SP> being provided with oppositely inclined teeth so that rotation of the sleeve 14 by a handle 15 varies the distance between the sleeves and accordingly the spring pressure. In the variation shown in Fig. 8 the spring parts 8<SP>1</SP> 8" bear respectively on sliding sleeves 16, 36, between flanges of which are cam shaped parts 38 carried by bolts in the sleeve 36, and the bolts are interconnected by a handle to vary the spring pressure. In Fig. 4, the handle 15 is connected by a rod 17 to the trailer chassis frame 18, so that compression of suspension springs connected to the axle 4 due to trailer load rotate the handle and varies the spring pressure. Specification 526.051 is referred to.