Valve actuator having small isolated plunger

• US 6,752,371 B2
• Filed: 06/19/2002
• Issued: 06/22/2004
• Est. Priority Date: 06/19/2002
• Status: Expired due to Term

• Current Assignee: Arichell Technologies Inc. (Sloan Valve Company)
• Original Assignee: Arichell Technologies Inc. (Sloan Valve Company)
• Inventors: Parsons, Natan E., Herbert, Kay, Guler, Fatih
• Primary Examiner(s): Bastianelli, John
• Application Number:
  US10/174,919
• Publication Number:
  US 20030234377A1
• Time in Patent Office: 734 Days
• Field of Search: 251/129.17, 251/129.15, 251/129.07, 251/54, 251/48, 251/331, 251/335.2
• US Class Current: 251/54
• CPC Class Codes: E03D 1/36 Associated working of inlet and outlet valves
• CPC Class Codes: E03D 5/10 operated electrically E03D5/01, E03D5/12 take precedence, e.g. by a photo-cell; also combined with devices for opening or closing shutters in the bowl outlet and/or with devices for raising/or lowering seat and cover and/or for swiveling the bowl

Abstract

A solenoid plunger (36) is disposed for reciprocation in a plunger pocket that is formed by the stationary parts of a solenoid-type actuator (10). A flexible diaphragm (22) closes the plunger pocket'"'"'s open mouth and is deformed by movement of a plunger (36) between an open position, in which it is displaced from a valve seat (20), and a closed position, in which it is seated on the valve seat and thereby prevents flow from a valve inlet (16) to a valve outlet (18). The diaphragm thereby isolates the plunger from the fluid thereby being controlled, but a separate, incompressible fluid fills the chamber in which the plunger reciprocates. A through-plunger passage (44, 56) provides a low-flow-resistance path for the incompressible fluid to flow into and out of the portion (52) of the plunger chamber behind the plunger as the plunger moves. This reduces actuation time and thus the energy required for an actuation. The chamber in which the plunger reciprocates is formed by elements (22, 26, 32, and 34) through which the incompressible fluid can diffuse only very slowly, so the actuator can be long-lived even if it small in size.

Claims

1. An electromagnetic actuator comprising:

A) a stationary assembly that includes;

i) a coil;

ii) a pocket wall that defines an armature pocket that has front and rear pocket ends and is closed except for a mouth at the front end thereof, and

iii) a flexible diaphragm that closes the mouth of the armature pocket and thereby forms with the pocket wall a substantially fluid-tight armature chamber;

B) an incompressible fluid, contained in the armature chamber and having a volume that bears to the armature chamber'"'"'s surface area a ratio of less than 0.2 centimeter, whose rate of loss from the armature chamber by diffusion through the materials of the pocket wall and the diaphragm is less than 2% per year; and

C) an armature that includes high-magnetic-permeability material, has front and rear armature ends, cooperates with the incompressible fluid to fill the armature chamber, and is disposed in the armature chamber for movement, in directions in which it can be urged by magnetic force resulting from current flow through the coil, between forward and rear positions, the front end of the armature so engaging the diaphragm when the armature is in its forward position that the diaphragm assumes a shape that extends farther forward than the shape assumed by the diaphragm when the armature is in its rear position.

2. An actuator as defined in claim 1 wherein the incompressible fluid consists essentially of a mixture of water and propylene glycol containing at least 30% propylene glycol.

3. An actuator as defined in claim 2 wherein:

A) the stationary assembly further includes a bobbin, about which the coil is wound, consisting essentially of polypropylene, and

B) the bobbin forms part of the pocket wall.

4. An actuator as defined in claim 3 wherein:

A) the stationary assembly further includes a rear pole piece comprising high-magnetic-permeability stainless steel; and

B) the rear pole piece forms part of the pocket wall.

5. An actuator as defined in claim 4 wherein:

A) the stationary assembly further includes a front pole piece consisting essentially of high-inagnetic-permeability stainless steel and disposed for ward of the rear pole piece; and

B) the front pole piece forms part of the pocket wall.

6. An actuator as defined in claim 1 wherein:

A) the stationary assembly further includes a bobbin, about which the coil is wound, consisting essentially of polypropylene, and

B) the bobbin forms part of the pocket wall.

7. An actuator as defined in claim 6 wherein the incompressible fluid consists essentially of a mixture of water and propylene glycol containing at least 30% propylene glycol.

8. An electromagnetic valve comprising:

A) a stationary assembly that includes;

i) a coil;

ii) a pocket wall that defines an armature pocket that has front and rear pocket ends and is closed except for a mouth at the front end thereof, and

iii) a flexible diaphragm that closes the mouth of the armature pocket and thereby forms with the pocket wall a substantially fluid-tight armature chamber;

B) a valve body forming a valve inlet, a valve outlet, and a valve seat;

C) an incompressible fluid, contained in the armature chamber and having a volume that bears to the armature chamber'"'"'s surface area ratio of less than 0.2 centimeter, whose rate of loss from the armature chamber by diffusion through the materials of the pocket wall and the diaphragm is less than 2% per year; and

D) an armature tat includes high-magnetic-permeability material, has front and rear armature ends, cooperates with the incompressible fluid to fill the armature chamber, and is disposed in the armature chamber for movement, in directions in which it can be urged by magnetic force resulting from current flow through the coil, between a forward position, in which the armature permits the diaphragm to be spaced from the valve seat and thereby permit fluid flow from the valve inlet through the valve outlet, and a rear position, in which the front end of the armature so engages the diaphragm as to seat it in the valve seat and thereby prevent fluid flow from the valve inlet to the valve outlet.

9. An electromagnetic valve as defined in claim 8 wherein the incompressible fluid consists essentially of a mixture of water and propylene glycol containing at least 30% propylene glycol.

10. An electromagnetic valve as defined in claim 9 wherein:

A) the stationary assembly further includes a bobbin, about which the coil is wound, consisting essentially of polypropylene, and

B) the bobbin forms part of the pocket wall.

11. An electromagnetic valve as defined in claim 10 wherein:

A) the stationary assembly further includes a rear pole piece comprising high-magnetic-permeability stainless steel; and

B) the rear pole piece forms part of the pocket wall.

12. An electromagnetic valve as defined in claim 11 wherein:

A) the stationary assembly further includes a front pole piece consisting essentially of high-magnetic-permeability stainless steel and disposed forward of the rear pole piece; and

B) the front pole piece forms part of the pocket wall.