Hydrostatic reversible vehicle drive controlled by brake application

Claim 1

A control device for a hydrostatic reversible driving system with a braking device, which includes: a main hydraulic circuit comprising a hydrostatic pump having a pump body portion pivotable in opposite directions and equipped with an adjusting device, and hydraulic motor means, and also includes a hydraulic control circuit comprising a driving engine, a control pump drivingly connected to said driving engine so as to rotate at a speed proportional to the speed of said driving engine, said control pump also being hydraulically connected to said hydraulic control circuit, and driving direction control valve means operatively connected to said adjusting device, said hydraulic control circuit also comprising: fluid reservoir means, a main control conduit, first and second and third branch conduits branching off from said main control conduit and arranged in parallel to each other and communicating with said fluid reservoir means, rigid orifice means interposed in said first branch conduit, output control valve means operatively connected to said main hydraulic circuit and interposed in said second conduit, adjustable orifice means interposed in said third conduit and movable from a closed position to an open position and vice versa, and spring means associated with said adjustable orifice means and continuously urging the same to its closed position, said adjustable orifice means being operatively connected to said braking device so as to be movable to its open position in conformity with the actuation of said braking device.