Automatic reverse speed control device including pump and brake restricting means

Claim 1

A reverse speed control device for a vehicle, comprising: a pump discharging a fluid in one direction in response to forward movement of the vehicle and in another direction in response to reverse movement of the vehicle, said fluid being discharged at a flow rate proportional to the vehicle speed; a brake pipe operatively connected to said pump for receiving fluid discharged from said pump when the vehicle is in reverse, said brake pipe being operatively connected to a wheel braking device actuated by fluid pressure applied thereto; a cutoff valve interposed between said brake pipe and said wheel braking device, such that said cutoff valve is biased to a closed position to operatively cut off fluid pressure in said brake pipe from said wheel braking device when the pressure in said brake pipe is below a predetermined pressure, and such that when the pressure in said brake pipe is greater than said predetermined pressure, said cut off valve is biased to an open position to operatively connect the fluid pressure in said brake pipe with said wheel braking device to allow said fluid to act on said wheel braking device to automatically brake a vehicle wheel when said fluid pressure exceeds said predetermined pressure when said vehicle is in reverse; a return pipe connected to said cut off valve such that fluid in said wheel braking device is returned to a fluid reservoir when said cut off valve is biased to said closed position; a brake restricting means for releasing fluid in said brake pipe when a flow rate of the fluid discharged from said pump into said brake pipe is less than a predetermined rate to prevent a rise of fluid pressure in said brake pipe.