APERFEICOAMENTOS EM TRANSMISSAO

1488233 Change-speed gear CLARK EQUIPMENT CO 24 Feb 1976 [24 Feb 1975] 07248/76 Heading F2D In a change-speed gear for off-highway vehicles of the kind having countershafts 24, 202 arranged in the same vertical plane as parallel input and output shafts 14, 116, with powershift clutches 58, 64, 210 providing three ratios in either direction through forward and reverse input clutches 38, 50, the third-ratio clutch 210 clutches to the countershaft 202 a wheel 206 meshing a preceding countershaft wheel 54, instead of, as in prior art (Fig. 1, not shown), clutching (at 110) thereto a wheel (106) meshing the preceding countershaft wheel 62. This provides increased axial space between the countershaft wheels 206, 108, for accommodating an addition wheel 304 for an additional reduction ratio 304, 402 in the final output. The arrangement shown in Fig. 4 also provides two ranges by a positive clutch 414 between the output shaft 116 and either of two wheels 402, 412, giving overall six ratios in each direction. As far as the first countershaft 24 and a shaft 26 aligned therewith the arrangement follows the prior art in having two meshed wheels 52, 54 fast respectively on a shaft 18 aligned with the input shaft 14 and on the first countershaft 24. A wheel 34 on the input shaft 14 meshes, through an idler a wheel 36 clutchable to the first countershaft 24 by a reverse clutch 50, whilst the forward clutch 38 clutches together the input shaft 14 and aligned shaft 18. The first, second and third ratio clutches 64, 58, 210 are as shown.