Brake system having a plurality of operational sources

A brake system comprising:

• a control member for developing a first pressure in a first operational fluid derived in a supply fluid received from a first pump means in response to a desired braking force applied to an input member;
• a shuttle valve connected to said control member and responsive to said supply fluid;
• sensor means for developing a flow through signal indicating a first position for said shuttle valve whereby said first operational fluid may be communicated to a remotely located master cylinder for effecting a brake application corresponding to said desired braking force;
• second pump means for developing a second pressure in a second operational fluid, said second pump means being connected to said master cylinder;
• computer means responsive to an input signal indicative of said braking force and in response to a predetermined flow through signal from said sensor means for supplying said second pump means with a pump actuation signal corresponding to said braking force for developing said second operational fluid which supplants the actuation of said master cylinder by said first operational fluid to effect said desired brake application;
• and
• a storage system for retaining a third operational fluid having a third pressure;
• said shuttle valve responding to a predetermined pressure in said supply fluid by shifting to a second position, said braking force moving said input member to activating a valve and allow said third operational fluid to flow from said storage system to said remotely located master cylinder with said shuttle valve in said second position, said third operational fluid thereafter operating said master cylinder by supplanting said first and second operational fluids to effect said desired brake application.

A brake system having a control member for developing a first pressure in a first operational fluid derived from a supply fluid received from a first pump means in response to a desired braking force applied to an input member and a shuttle valve positioned by said supply fluid at a first location whereby said first operational fluid is communicated to a remote master cylinder for effecting a brake application corresponding to said desired braking force, said shuttle valve being positioned by a resilient means at a second location in response to a predetermined pressure in said supply fluid such that back-up operational fluid is communicated to said remote master cylinder to effect a brake application, said brake system being characterized by sensor means for developing an operational signal indicating flow of said first operational fluid through said shuttle valve to said remote master cylinder;

• computer means responsive to an input signal indicative of said desired braking force and responsive to a predetermined operational signal from said sensor means for activating a second pump means to develop a second fluid pressure in a second operational fluid, said second operational fluid being communicated to said remote master cylinder to supplant the actuation thereof by said first operational fluid and effect said desired brake application;
• and a storage system for retaining a third operational fluid having a third fluid pressure, said braking force moving said input member to activate a valve and thereafter allow said third operational fluid to flow from said storage system to said remotely located master cylinder with said shuttle valve in said second position, said third operational fluid being combined with said back-up operational fluid to operate said master cylinder by supplanting said second operational fluid and effect said desired brake application.