# US 5,701,794 A · Brake booster provided with a noise shielding member

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- Number: US 5,701,794 A
- Document ID: US5701794A
- Status: Granted
- Kind: A
- Application number: 08/699,742
- Filed: 1996-08-20
- Granted: 1997-12-30
- Earliest claimed: 1995-12-19
- Assignees: Mando Machinery Corporation
- Inventors: Hang-Byong Cha
- Web page: https://patentgrep.com/patent/US5701794A

## CPC

- G10K 11/161: {in systems with fluid flow (G10K11/162 takes precedence; gas flow silencers or exhaust apparatus for machines or engines in general or for internal combustion engine F01N, noise absorbers in pipes or pipe systems F16L55/02; noise absorption in air conditioning and ventilation F24F13/24; silencing exhaust or propulsion jets in aircraft B64D33/06)}
- B60T 13/52: indirect, i.e. vacuum booster units
- B60T 17/008: {Silencer devices}
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- 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 brake booster includes a valve housing, an input rod movably mounted in the valve housing, a main filter, a noise absorbing member, a spring seat, a return spring for biasing the input rod, and a noise shielding member. The main filter, the noise absorbing member, the spring seat, the noise shielding member are fixed on the input rod and move integrally with the latter. The noise shielding member spaced apart from the noise absorbing member reduces the air suction noise.

## Claims

### Claim 1

A brake booster comprising:
a valve housing;
an input rod movably mounted in the valve housing;
an air valve mounted in the valve housing, the air valve being opened by the input rod;
a main filter fixed on the input rod;
a noise absorbing member fixed on the input rod;
a spring seat fixed on the input rod;
a return spring for biasing the input rod, the return spring contacting the spring seat; and
a noise shielding member fixed on the input rod, the noise shielding member spaced apart from the noise absorbing member toward the air valve, wherein the main filter, the noise absorbing member, the spring seat, the noise shielding member move integrally with the input rod.

### Claim 2 (depends on 1)

The brake booster of claim 1, further comprising: a secondary filter fixed, between the noise absorbing member and the noise shielding member, on the input rod, the secondary filter moving with the input rod.

### Claim 3 (depends on 2)

The brake booster of claim 2, wherein the spring seat, the noise shielding member, the secondary filter, the noise absorbing member and the main filter are fixed in order on the input rod from the air valve.

### Claim 4 (depends on 1)

The brake booster of claim 1, wherein the noise shielding member is made of steel.