Micro-metering system

• US 4,271,989 A
• Filed: 03/27/1979
• Issued: 06/09/1981
• Est. Priority Date: 03/27/1979
• Status: Expired due to Term

• Current Assignee: Physics International Company
• Original Assignee: Physics International Company
• Inventors: O'Neill, Cormac G., Smiley, Parker C.
• Primary Examiner(s): SKAGGS JR, H GRANT
• Application Number:
  US06/024,316
• Time in Patent Office: 805 Days
• Field of Search: 222/43, 222/282, 222/305, 222/307, 222/308, 222/333, 222/335, 222/344, 222/361, 222/362, 222/504, 222/135, 222/136, 222/137, 222/138, 222/139, 251/129, 251/57, 137/625.61, 137/625.65
• US Class Current: 222/282
• CPC Class Codes: F01L 25/08 by electric or magnetic means
• CPC Class Codes: F04B 43/04 Pumps having electric drive
• CPC Class Codes: G01F 11/086 using an auxiliary pressure to cooperate with the diaphragm or bellows
• CPC Class Codes: Y10T 137/8667 Reciprocating valve

Abstract

A housing having an inlet port and an outlet port utilizes a variable volume cavity connected to the housing and includes a device for limiting the volume of the cavity which is alternately filled through the inlet port and exhausted through the outlet port using a spool valve. The spool valve is arranged to prevent continuous communication of fluid between the inlet and outlet ports. The volume of the variable volume cavity can be varied using electro-expansive or piezoelectric apparatus. The spool valve is reciprocated between the inlet and outlet ports using an electromechanical device and a motion amplifier.

Claims

1. An apparatus for controlling the flow of fluid comprising

means defining a primary housing having an inlet port and an outlet port,

means defining a first variable volume cavity in fluid communication with said primary housing,

means for varying the volume of said cavity according to pressure of said fluid,

means for limiting the volume of said variable volume cavity comprising

means defining a support bracket,

an electroexpansive member having one end bearing against said support bracket and having the other end bearing against said means for varying the volume of said cavity according to pressure of said fluid, and

means for applying a voltage across said electroexpansive member whereby said electroexpansive member contracts and expands against said means for varying the volume of said cavity to limit the volume thereof, and

means for alternately communicating said inlet port with said cavity and said outlet port with said cavity.

2. An apparatus for controlling the flow of fluid comprising

means defining a primary housing having a first inlet port, a first outlet port, second inlet port and a second outlet port,

means defining a first variable volume cavity comprising a first flexible diaphragm in fluid communication with said primary housing,

means defining a second variable volume cavity comprising a second flexible diaphragm in fluid communication with said primary housing,

means for limiting the volume of said first variable volume cavity comprising

a first housing bracket attached to said primary housing,

a set screw adapted to engage said first housing bracket and bear against said first flexible diaphragm,

means for varying the volume of said second variable volume cavity comprising,

a second housing bracket attached to said primary housing,

an electro-expansive member having one end bearing against said second housing bracket and having its other end bearing against said second flexible diaphragm,

means for applying a voltage to said electro-expansive member whereby said electro-expansive member contracts and expands against said second flexible diaphragm to vary the maximum deflection thereof, and

means for alternately communicating said first inlet port with said first cavity concurrently with communicating said second inlet port with said second cavity, and then communicating said first outlet port with said first cavity concurrently with communicating said second outlet port with said second cavity.

3. An apparatus for controlling the flow of fluid comprising

means defining a primary housing having an inlet port and an outlet port,

means defining a first variable volume cavity in fluid communication with said primary housing,

means for varying the volume of said cavity according to pressure of said fluid,

means for limiting the volume of said variable volume cavity, and

means for alternately communicating said inlet port with said cavity and said outlet port with said cavity comprising

a shaft slidably disposed in said housing and adapted to reciprocate therein,

means defining a second cavity in said shaft,

means for alternately reciprocating said shaft in said primary housing to place said second cavity in said shaft alternately between said inlet port of said housing and said opening of said first variable volume cavity, and between said outlet port of said primary housing and said opening of said first variable volume cavity, said means comprising

a stack of piezoelectric elements varying in dimension according to applied voltage,

a spring diaphragm adapted to engage one end of said stack of piezoelectric elements and vary in dimension therewith, said spring diaphragm in fluid communication with said shaft, said spring diaphragm comprising

a generally planar central member adapted to engage one end of said stack of piezoelectric elements,

an outer annular ring support member,

a middle annular ring member disposed between said central member and said outer annular ring support member and flexibly connected to each of said members.