Precision fluid dispense valve

• US 4,489,863 A
• Filed: 02/11/1982
• Issued: 12/25/1984
• Est. Priority Date: 02/11/1982
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lorber, Harold W., Horchos, Leonard A.
• Primary Examiner(s): Tollberg, Stanley H.
• Assistant Examiner(s): Shaver, Kevin P.
• Application Number:
  US06/347,843
• Time in Patent Office: 1,048 Days
• Field of Search: 222/504, 222/189, 251/139, 251/141, 251/65
• US Class Current: 222/504
• CPC Class Codes: F16K 31/082 using a electromagnet and a permanent magnet

Abstract

A micro dispense valve arrangement for accurately dispensing minute quantities of a fluid. The valve arrangement interfaces an enclosed interior region under pressure with an exterior region of less pressure through an orifice opening. The orifice wall is tapered from interior to exterior to bound a frustoconical region constricting toward the exterior to accommodate a magnetizable pellet or ball. The ball is held in its seated position against the orifice wall by permanent magnets imbedded in the wall. An AC coil surrounding the orifice opening acts when energized to cause the ball to move between its seated or closed position and a non-magnetizable screen in its open position. The frequency and duration of applied positive and negative pulses driving the coil act to control the on/off fluid flow duty cycle of the valve.

Claims

1. A dispense valve arrangement for accurately metering fluid under pressure in quantities dependent upon the frequency and duration of electrical pulses, comprising:

a non-magnetic wall segment having an annular frustoconical orifice with a tapered wall that constricts in a direction away from said fluid;

a sphere of magnetizable material coated with non-magnetic material, positioned within said orifice for closing said orifice and preventing escape of said fluid under pressure;

a permanent magnet embedded within said non-magnetic wall segment at or near the surface of said tapered wall, positioned to seat said sphere against said tapered wall to close said orifice;

an AC coil, concentrically wound to surround said non-magnetic wall segment, responsive to electrical pulses to create a magnetic field within said frustoconical orifice without the use of magnetic pole pieces within said frustoconical orifice, said magnetic field overriding said permanent magnet and causing said sphere to unseat and open said orifice; and

,

a screen of non-magnetic material for retaining said sphere within said orifice when said AC coil is energized by said electrical pulses to unseat said sphere.

2. The dispense valve as set forth in claim 1 wherein said fluid is liquid.

3. The dispense valve as set forth in claim 1 wherein said fluid is gas.

4. The dispense valve as set forth in claim 1 wherein the repetition rate of said electrical pulses determines the rate at which said sphere of magnetizable material oscillates between its closed and open position and the duration of said pulses determines the respective time periods during which said orifice is open and closed.

5. A dispense valve arrangement for accurately metering quantities of fluid between an interior region under pressure and an exterior region of less pressure, said valve comprising:

a non-magnetic wall section for interfacing said interior region to said exterior region, said wall section having an annular frustoconical orifice with its wall tapered between said interior and exterior region so as to constrict in the direction toward said exterior region;

a sphere of magnetizable material coated with non-magnetic material positioned within said orifice for closing said orifice and preventing fluid passage between said interior region and exterior region;

permanent magnet means embedded within said non-magnetic wall segment at or near the surface of said tapered wall, positioned to attract and seat said sphere against said orifice wall to close said orifice;

AC coil means surrounding said orifice and responsive to AC signals to create a magnetic force within said frustoconical orifice without the use of magnetic pole pieces within said orifice to override the force exerted on said sphere by said permanent magnet means and fluid and thereby cause said sphere to unseat and open said orifice; and

a screen of non-magnetic material for inhibiting said sphere from moving out of said orifice when said AC signals are applied.

6. The dispense valve as set forth in claim 5 wherein said AC signals comprise alternating pulses.

7. The dispense valve as set forth in claim 6 wherein the repetition rate of said pulses determines the rate at which said magnetizable sphere oscillates between its closed position and open position and the duration of said pulses determines the respective time periods during which said orifice is in its closed position and open position.

8. The dispense valve as set forth in claim 7 wherein said fluid is liquid.

9. The dispense valve as set forth in claim 7 wherein said fluid is gas.