# US 2014/0150420 A1 · Master cylinder, in particular for a controlled brake system

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- Number: US 2014/0150420 A1
- Document ID: US20140150420A1
- Status: Published application
- Kind: A1
- Application number: 14/115,702
- Filed: 2012-05-04
- Published: 2014-06-05
- Earliest claimed: 2011-05-05
- Assignees: Continental Teves AG & Co. oHG
- Inventors: Harald König; Peter Drott; Udo Jungmann; Andreas Bischoff
- Web page: https://patentgrep.com/patent/US20140150420A1

## CPC

- B60T 11/20: Tandem, side-by-side, or other multiple master cylinder units
- B60T 8/38: including valve means of the relay or driver controlled type
- B60T 11/228: Pressure-maintaining arrangements, e.g. for replenishing the master cylinder chamber with fluid from a reservoir (B60T11/232 takes precedence)
- B60T: VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL (electrodynamic brake systems for vehicle, in general B60L; brakes per se, i.e. devices where braking effect occurs, including ultimate brake actuators, F16D); ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES

## Abstract

A master cylinder for a controlled brake system, including at least one piston which is displaceable in a housing and is sealed with respect to a pressure chamber by a sealing element arranged in an annular groove of the housing, which pressure chamber is connectable to an unpressurized supply chamber by control passages formed in the piston. The piston 46 is formed in at least two parts, including a main body and an annular control element, the control passages being provided in the control element.

## Claims

### Claim 1

A master cylinder, for a controlled brake system, comprising at least one piston which is displaceable in a housing and is sealed with respect to a pressure chamber by means of a sealing element arranged in an annular groove of the housing, which pressure chamber is connectable to an unpressurized supply chamber by control passages formed in the piston wherein the piston is formed in at least two parts, comprising a main body and an annular control element, the control passages being provided in the control element.

### Claim 2 (depends on 1)

The master cylinder as claimed in claim 1, wherein the annular control element is arranged in an external groove of the main body.

### Claim 3 (depends on 1)

The master cylinder as claimed in claim 1, wherein the control passages have a control edge formed parallel to an end face of the piston, which control edge is formed on the main body.

### Claim 4 (depends on 3)

The master cylinder as claimed in claim 3, wherein the control edge is formed by a side wall of the external groove and an outer side of the main body.

### Claim 5 (depends on 1)

The master cylinder as claimed in claim 1, wherein the control passages are provided as axial grooves on an outer side of the control element.

### Claim 6 (depends on 1)

The master cylinder as claimed in claim 1, wherein the control element is in the form of a corrugated ring.

### Claim 7 (depends on 3)

The master cylinder as claimed in claim 3, wherein the control passages are provided as gaps between ribs on an inner side of the control element, the ribs projecting axially beyond the control element on the side of the control element oriented towards the control edge.

### Claim 8 (depends on 1)

The master cylinder as claimed in claim 1, wherein the main body is provided as a turned or extruded part.

### Claim 9 (depends on 1)

The master cylinder as claimed in claim 1, wherein the main body is made of aluminum.

### Claim 10 (depends on 1)

The master cylinder as claimed in claim 1, characterized in that the control element is provided as a reversibly deformable preform which can be expansion-fitted to the main body.

### Claim 11 (depends on 1)

The master cylinder as claimed in claim 1, wherein the control element is made of plastic material.

### Claim 12 (depends on 1)

The master cylinder as claimed in claim 1, wherein the control element is made of resilient sheet metal.

### Claim 13 (depends on 2)

The master cylinder as claimed in claim 2, wherein the external groove is provided in the region of a reduced diameter of the main body.