Hydraulic brake booster
AssigneeRobert Bosch GmbH
InventorHeinz Leiber
Life of this patent
Estimating the term…
Abstract
The invention relates to a hydraulic brake booster for a vehicle brake apparatus which is provided with a pressurizing apparatus which has a pump and a reservoir. When the reservoir pressure fails, a switchover piston which is subject to the reservoir pressure can disengage a stop for the push rod of the control valve. The push rod is supported on the stop when the pressure supply to the reservoir is intact and after the control valve switches over in the direction of brake activation, in order to give the driver a sense of the added brake force. In the same event, a support of a pedal activation stem on a movable auxiliary cylinder is removed. When the reservoir pressure supply fails, however, this support is made available, in order to enable an immediate mechanical actuation of the main cylinder portion of the brake booster.
Claims18
A hydraulic brake booster for a vehicle brake apparatus comprising pressurizing apparatus with a pump and a pressurized reservoir, a reservoir-switchover piston adapted to be subjected to the pressure in the pressurized reservoir and engagable with a control valve, said control valve being associated with a pair of hydraulic main cylinders and each having connection means adapted to control both said pressurizing apparatus connected with the said main cylinders and said main cylinders connected with a relief means, at least one of said main cylinders including piston cooperating means cooperating with pedal-operated means and said piston cooperating means adapted to be operated by said pedal-operated means on pressure failure, said piston cooperating means having at least one main cylinder including an auxiliary pressure means, said auxiliary pressure means including an auxiliary cylinder, piston means being coextensive with said at least one main cylinder, said pressurizing apparatus including a refill container comprising a container relief means, said auxiliary pressure means communicating with said container relief means through a valve means and said valve means being coupled with said reservoir switchover piston.
Dependencies are inferred from the claim text.