| 摘要 |
<p>A diaphragm (60) for a brake booster (10) having an annular inner bead (62) with first and second radial surfaces (86, 70) separated by an apex (82). The second radial surface (86) has a plurality of indentations (80) that extend from the apex. In response to a positive pressure differential created by vacuum in a first chamber (28) and air in a second chamber (20), an output force is developed to effect a brake application corresponding to an input force. This positive pressure differential acts on the annular bead to urge said first radial face into engagement with a wall to prevent communication between the first and second chambers during a brake application. In the absence of the presence of vacuum in the first chamber, the input force acts on the wall to develop an operational pressure in the first chamber to develop a negative pressure differential between the first and second chambers. This negative pressure differential acts on the diaphragm to rotate the annular inner bead about the apex to move the first radial face away from the wall and allow communication between the first and second chambers through the indentations to attenuate the negative pressure differential and allow an input force to effect the brake application.</p> |
