Patent ID: 7213499

Claim:
A brake system with a boost unit that is secured to a panel of a vehicle that separates an engine compartment from a passenger compartment, said boost unit having a housing that retains a valve body with a cylindrical projection that extends through a first opening in the housing and into the passenger compartment, a boot that is located on the panel with an end that extends through the first opening in the housing and is secured to an input rod, a valve that is located within a first bore of the valve body and is responsive to an input force that is applied to the input rod to selectively communicate air from the engine compartment to a chamber in the boost unit by way of the first bore for creating a pressure differential across a movable wall in the boost unit, the pressure differential acting on the movable wall to develop an output force to effect a brake application, and a spacer that is located between the panel and the boost unit for off-setting the boost unit from the panel into the engine compartment; said spacer being characterized by a cylindrical body with second bore that extends from a first end and to a second end, a radial wall that extends from the cylindrical body adjacent said second end, a peripheral wall integral with said radial wall that axially extends to a radial plane past said second end of the cylindrical body to define a u-shaped space around said cylindrical body adjacent said second end, a plurality of axial annular supports that extend from said radial wall that are located in a desired pattern around said cylindrical body, said peripheral wall having a first radial opening located along a base through which air from the engine compartment is communicated into said u-shaped space, said cylindrical body having a second radial opening located at an apex of said base that extends from said second end toward said radial wall and a gasket located between said peripheral wall and second end of said cylindrical body and the booster to seal said u-shaped space such that air flows through said first radial opening in said peripheral wall and into the sealed u-shaped space and is divided into substantially equal volumes of air that flows along first and second paths around said cylindrical body, through said second radial opening and into said second bore in cylindrical body for distribution to the first bore in the valve body during a brake application, said first and second paths extending the length of travel of air from said first radial opening to said first bore and as a result some noise that is generated in the engine compartment is absorbed by said gasket prior to passing through said second radial opening.