Latching solenoid valve

• US 5,915,665 A
• Filed: 10/27/1997
• Issued: 06/29/1999
• Est. Priority Date: 10/27/1997
• Status: Expired due to Fees

• Current Assignee: Kohler Company
• Original Assignee: Kohler Company
• Inventors: Quella, John, Karsten, Lee, Witt, Kevin, Paese, Andrew J.
• Primary Examiner(s): LEE, KEVIN L
• Application Number:
  US08/957,890
• Time in Patent Office: 610 Days
• Field of Search: 251/30.02, 251/30.03, 251/30.04, 251/45, 251/65, 251/129.17, 251/129.15
• US Class Current: 251/30.04
• CPC Class Codes: E03C 1/04 Water-basin installations specially adapted to wash-basins or baths valves, faucets, mixing valves, taps F16K
• CPC Class Codes: E03C 1/05 Arrangements of devices on wash-basins, baths, sinks, or the like for remote control of taps remote control of taps or the like per se F16K
• CPC Class Codes: F16K 31/402 acting on a diaphragm

Abstract

A pilot valve is operated by a solenoid formed by a coil wound around a non-magnetic spool that has a bore. A rare earth permanent magnet is inside the bore adjacent one end and abuts a flux concentrator farther inside the bore. A plunger is slidably located within the bore biased away from the flux concentrator by a spring and projects out another end of the bore. An enclosure of magnetic material completes a magnetic flux path around the solenoid and has an aperture though which the plunger projects. The pilot valve includes a cage of rigid non-magnetic material which abuts the enclosure and has a recess which supports the plunger out of contact with the housing. The plunger selectively opens and closes a pilot tube through the cage to operate a diaphragm the responds by engaging a primary valve seat to control the flow of fluid through a valve body.

Claims

1. A latching solenoid valve comprising:

a solenoid having a bore and a coil for producing a magnetic field when an electric current flows there through;

a permanent magnet located within the bore;

a flux concentrator of magnetically permeable material located within the bore;

a plunger of magnetically permeable material slidably located within the bore and projecting outward from the solenoid;

an enclosure of magnetically permeable material containing the solenoid and having a first member that contacts one of the permanent magnet and the flux concentrator, and a second member with an aperture through which the plunger extends;

a cage of non-magnetic material coupled to the enclosure and having a recess into which an end of the plunger is received and supported, the cage including a pilot tube with a first opening into the recess and with a second opening, the cage having a pilot valve seat around the first opening and a bleed hole extending through the cage from the recess;

a valve body coupled to the enclosure and having an inlet and an outlet in communication through an aperture with the inlet, wherein a primary valve seat extends around the aperture; and

a resilient diaphragm cooperating with the cage to form a chamber into which the bleed hole communicates, and responding to pressure within the chamber by selectively engaging the primary valve seat to close the aperture, the resilient diaphragm having a pilot aperture which communicates with the outlet and within which the pilot tube is received.

2. The latching solenoid valve as recited in claim 1 wherein the solenoid comprises a spool formed of non-magnetic material about which the coil is wound.

3. The latching solenoid valve as recited in claim 1 wherein the plunger has a resilient seal that selectively engages the a pilot valve seat.

4. The latching solenoid valve as recited in claim 1 wherein the flux concentrator includes a seal that prevents fluid from flowing through the bore past the flux concentrator.

5. A latching solenoid valve comprising:

a housing of magnetic material having an open end and a closed end with threaded aperture;

a pole piece is threaded into the threaded aperture;

a spool formed of non-magnetic material within the housing and having a bore;

a solenoid coil wound on the spool for producing a magnetic field when an electric current flows there through;

a permanent magnet located within the bore of the spool and abutting the pole piece;

a flux concentrator of magnetically permeable material located within the bore of the spool abutting the permanent magnet;

a plunger of magnetic material slidably located within the bore of the spool and projecting outward from the spool;

a spring biasing the plunger away from the flux concentrator;

an end cap of magnetic material engaging the housing and closing the open end, the end cap having an aperture through which the plunger extends without contacting the end cap;

a cage of rigid non-magnetic material coupled to the end cap and having opposing first and second sides with the first side having a recess within which an end of the plunger is received and supported, the cage including a pilot tube having a pilot valve seat at one end which opens into the recess and having a second end, the cage further including a bleed hole extending between the recess and the second side;

a valve body coupled to the housing and including an inlet and an outlet in communication through an opening with the inlet, wherein a primary valve seat extends around the opening; and

a resilient diaphragm adjacent the second side of the cage to form a pilot chamber there between, and responding to pressure within the chamber by selectively engaging the primary valve seat to close communication between the inlet and outlet, the resilient diaphragm having a pilot aperture within which the pilot tube is received wherein the second end of the pilot tube communicates with the outlet.

6. The latching solenoid valve as recited in claim 5 wherein the spring is within the bore of the spool.

7. The latching solenoid valve as recited in claim 5 wherein the permanent magnet is a rare earth magnet.

8. The latching solenoid valve as recited in claim 5 wherein the plunger has a resilient seal that selectively engages the a pilot valve seat.

9. The latching solenoid valve as recited in claim 5 wherein the flux concentrator includes a seal that prevents fluid from flowing through the bore past the flux concentrator.