GB1464867A - Servo boosters - Google Patents

Abstract

1464867 Vacuum servo-boosters GIRLING Ltd 16 Sept 1974 [18 Sept 1973] 43683/73 Heading F2F A power diaphragm 24 of a booster is actuated by differential pressure controlled by valve means, and is supported by a plurality of radially extending fingers 51 held in regularly, circularly spaced and radially fixed locations mechanically coupled to an annular fulcrum plate 90 providing a fulcrum for finger deflection and coaxially mounted on an output rod 92. When not actuated, a chamber 26, connected to a vacuum source, communicates via a passage 82 an opening between a seat 72 and an axially flexible movable member 70, a passage 86 with a chamber 28 on the other side of the diaphragm. Upon actuation an input member 48 closes the opening and then opens communication between the chamber 28 and atmosphere by movement of a seat 74 from the member 70. Diaphragm movement acts on the fingers 51 so that they pivot about the plate 90 to transmit reaction to a thrust member 46 and the input member 48. Fig. 1a shows a lug 120 on each finger 51 gripping the outer periphery of the plate 90; Fig. 2a shows a ring 122 having lugs 124 extending between respective fingers 51, each finger having a recess 128 on each side; Fig. 3a shows a ring 130 having a pair of lugs 132a, 132b extending through each finger 51, each latter lug extending over a respective recess 131 in the periphery of the plate 90.