| 摘要 |
<p>A change-speed transmission in which gear-ratios are established by engagement of appropriate fluid-pressure operated friction brakes and clutches (CF, CR, B3, 82, B1) includes a manually-operable control (41) for partially-engaging, to provide retardation of a vehicle, those friction brakes and/or clutches not in use at any time in establishing a particular gear-ratio. The control (41) operates valves (23, 22, 21, 33, 32, 31) which ensure that the rates of power absorption per unit friction area in all partially-engaged brakes and/or clutches is approximately equal and that the degree of retardation so provided decreases with each down-shift of the transmission.</p> |
