Retarding means for motor vehicles

摘要

A change-speed transmission in which gear-ratios are established by engagement of appropriate fluid-pressure operated friction brakes and clutches includes a manually-operable control 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 operates valves 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.