Brake pressure control apparatus for a hydraulic automotive vehicle brake system

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• and a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake, and
• (d) a valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system with a brake pressure master unit, with at least one brake pressure slave unit connected to the former through a pressure line for the actuation of a brake, with a pressure-controlled inlet valve which is positioned in said pressure line and is switchable from an open normal position into a restricted position in which said brake pressure master unit is connected through a restrictor orifice to said brake pressure slave unit and which is furnished with a control piston which in one direction is subject to the pressure in said pressure line and in the opposite direction subject to the action of a spring and of the pressure in a return line which is connected to said valve and which controls a connection between said brake pressure slave unit and said return line, said return line containing an outlet valve which is controllable by a control device, which blocks said return line in its position of rest and which releases said return line in its switching position, characterized:

• in that said inlet valve is provided with a seat valve with a valve element which is actuatable by the said control piston and which in the restricting position blocks a valve seat which is disposed parallel to the said restrictor orifice, and in that in the restricting position said control piston is movable independently of the said valve element under the control initiated by the pressure,
• in that said control piston is accommodated within a longitudinal bore of a cylindrical valve insert which bears said valve seat at one end and which is furnished with valve bores ending up in said longitudinal bore at a distance from each other and being connectible to each other by means of a control groove in the said control piston, and
• in that in a groove in its generated surface said valve insert is provided with a ring-shaped filter insert which covers the mouth of a valve bore.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• and a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake,
• (d) a valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line, and
• (e) a longitudinal bore within which said control piston moves and forming a ring-shaped passage between an outside surface of said control piston and said longitudinal bore within which the said control piston moves and by which the said brake is connected to the said return line.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake, and
• (d) a valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line;
• and filter elements positioned on either side of said restrictor orifice.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• and a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake, and
• (d) a ball valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• and a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake, and
• (d) a ball valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line, and
• (e) a stationary valve seat.

A brake pressure control apparatus for a hydraulic automotive vehicle brake system, said apparatus comprising:

• a brake pressure master unit;
• a brake;
• a pressure line for conducting pressure fluid from said brake pressure master unit to said brake;
• a return line for conducting pressure fluid away from said brake;
• an outlet valve in said return line for controlling flow of pressure fluid through said return line away from said brake;
• and a pressure-controlled inlet valve in said pressure line and connected to said return line and having:
• (a) a spring,
• (b) a control piston having an annular groove and defining a movable valve seat, said control piston movable:
• (1) in a first direction in response to the pressure of said pressure fluid in said pressure line, and
• (2) in a second direction opposite to said first direction in response to said spring and the pressure of said pressure fluid in said return line,
• (c) a restrictor orifice through which said pressure fluid is conducted to said brake, and
• (d) a valve element movable in response to movement of said control piston and spaced from said movable valve seat in response to movement of said control piston in said first direction to block said pressure line and connect said brake to said return line, and
• (e) a valve insert having:
• (1) an upper end,
• (2) a lower end,
• (3) a longitudinal bore extending between said upper end of said valve insert and said lower of said valve insert and within which said control piston moves,
• (4) a first valve bore extending from an outside surface of said valve insert at said pressure line leading to said brake and opening into said longitudinal bore of said valve insert,
• (5) a second valve bore extending from said outside surface of said valve insert at said return line and opening into said longitudinal bore of said valve insert, said second valve bore connected to said first valve bore by said annular groove of said control piston through said longitudinal bore in said valve insert, and
• (b) a stationary valve seat mounted on an end of said valve insert.