VARIABLE RATE ANEROID CAPSULE

摘要

A variable rate aneroid capsule comprises a bellows sealed with vacuum inside and having helically formed convolutions defining an outer helical threaded surface that is matingly engageable with the helical threaded surface of a nut that is axially slidably but non-rotatably mounted in a stationary housing. The bellows has end shafts extending rotatably through the housing for connection of shaft to a device to be moved linearly, and for connection of a shaft through an adjustably mounted sleeve to a lever 42 for rotating the bellows to progressively engage the convolutions with the nut to render the engaged convolutions inactive by preventing expansion or contraction of the engaged convolutions and thereby reducing the number of active unengaged convolutions to thereby vary the stroke and spring rate of the bellows for the same pressure differential across the surface of the bellows.