Pneumatic potentiometer
OwnerWilliam D. Ellsworthinventor
Life of this patent
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Abstract
Fluid under pressure, such as compressed air, is applied to one end of an elongate, thin, tubular plenum, the opposite end of which exhausts to the atmosphere. The plenum has intermediate its ends a plurality of axially spaced exhaust ports, which are connected to a valve mechanism having a rotary or reciprocable valve stem, which can be adjusted selectively to connect any one of the plenum exhaust ports through a single output port to a pneumatically operated device. The pressure of the air traveling through the plenum drops at a substantially linear rate, so that the pressures at the spaced exhaust ports can be plotted against the respective distances of these ports from the inlet end of the tubular plenum, thereby to provide a curve which can be used for predicting the pressure at any given point along the length of the plenum.
Claims12
An instrument for selectively supplying any one of a plurality of different, predetermined fluid pressures to a fluid operated device, comprising
- means defining an elongate, tubular plenum having an inlet at one end thereof, an outlet at its opposite end, and a plurality of spaced exhaust openings formed therein at axially spaced points intermediate its ends,
- means for connecting said inlet to a supply of fluid under a first predetermined pressure,
- means for connecting said outlet to a system maintained at a pressure lower than said first predetermined pressure, so that said fluid flows through said plenum from said inlet to said outlet,
- said plenum having a substantially uniform diameter throughout its length, whereby the pressure of said fluid drops in a substantially linear manner during its passage through said plenum, and thus presents a different, predetermined fluid pressure at each of said exhaust openings in said plenum, and
- valve means having a single output port disposed to be secured in communication with said fluid operated device,
- said valve means including a movable selector element for selectively placing any one of said spaced exhaust openings in communication with said output port, thereby to apply a predetermined one of said different fluid pressures to said device.
A pneumatic potentiometer for selectively supplying compressed air or gas at any one of a plurality of different, predetermined pressures to a pneumatically operated device, comprising
- a valve mechanism having an output port connected to said device,
- means defining an elongate, tubular plenum of substantially uniform internal diameter, said plenum being open at one end to atmosphere and disposed to be connected at its opposite end to a supply of air under pressure, whereby air is disposed to flow continuously through said plenum under a pressure which drops substantially linearly during flow of the air from said one end to said opposite end of the plenum, and
- means defining a plurality of exhaust ducts, each of said exhaust ducts opening at one end on said plenum at axially spaced points therealong, and at their opposite ends on said valve mechanism,
- said valve mechanism including a movable valve stem having a single output duct, said output duct having one end opening at all times on said output port, and having an opposite end movable with said stem selectively into registry with one of said exhaust ducts, thereby selectively to apply one of a plurality of different air pressures to said output port.
Dependencies are inferred from the claim text.