Double seat value with switch monitoring design

• US 5,771,926 A
• Filed: 11/03/1995
• Issued: 06/30/1998
• Est. Priority Date: 11/03/1995
• Status: Expired due to Fees

• Current Assignee: Bosch Systems de Freinage
• Original Assignee: Bosch Systems de Freinage
• Inventors: Medal, George L., Worley, Allan G.
• Primary Examiner(s): CHAMBERS, A MICHAEL
• Application Number:
  US08/553,105
• Time in Patent Office: 970 Days
• Field of Search: 137/240, 137/614.11, 137/552, 137/554, 137/614.17, 137/614.18, 137/614.19
• US Class Current: 137/554
• CPC Class Codes: F16K 1/443 the seats being in series
• CPC Class Codes: F16K 37/0041 for measuring valve parameters F16K37/0033 takes precedence
• CPC Class Codes: Y10T 137/4259 With separate material addition
• CPC Class Codes: Y10T 137/8175 Plural
• CPC Class Codes: Y10T 137/8242 Electrical
• CPC Class Codes: Y10T 137/88038 One valve head carries other valve head

Abstract

A switch mounting arrangement enables close monitoring of seat position in a single-axis double-seat valve. The switch mounting arrangement includes a switch element disposed within a longitudinal bore of a mounting block. The bore also houses a transducer element that is adjustable within the bore to permit relative placement between the switch element and the transducer element so that very slight movement of the switch element and corresponding movement of the valve seat may be detected. This arrangement may then be incorporated into a monitoring circuit and/or control system.

Claims

1. A sensor construction for sensing movement of a valve with respect to a valve seat, the valve including a actuator stem providing movement of the valve along a valve axis, the sensor construction comprising:

a sensor housing disposed proximate to the actuator stem defining a bore transverse to the valve actuator stem;

a limit switch plunger rod having a first portion disposed within the bore of the housing and having a second portion in contacting relation with a portion of the valve actuator stem, the plunger rod being displaced when the actuator stem is moved; and

a proximity sensor transducer spaced from the limit switch plunger rod portion within the bore of the housing, the proximity sensor transducer detecting transverse movement of the plunger rod, converting the sensed transverse movement to an electrical sensing signal, and providing the electrical sensing signal at a pair of output terminals when movement of the plunger rod is detected.

2. The sensor construction of claim 1 wherein the electrical sensing signal provides an information content corresponding to movement detected to within about 0.005 inches of displacement of the valve stem.

3. The sensor construction of claim 1 wherein the electrical sensing signal is an analog voltage having a magnitude proportional to the sensed transverse displacement.

4. A circuit for monitoring the position of a single-axis double-seated valve, the valve including a first valve segment and a second valve segment, each of the valve seats disposed in a single axis, the monitoring circuit comprising:

a first sensor for sensing movement of the first valve segment and providing a first signal when movement is sensed;

a second sensor for sensing movement of the second valve segment and providing a second signal when movement is sensed; and

a logic circuit coupled with the first and second sensors providing an output signal indicating a safe condition in response to the receipt of a predetermined sequence of the first and second signals.

5. The invention as in claim 4 wherein the monitoring circuit provides a signal indicating an unsafe position of the valve when the first sensor senses an open position or when the second sensor senses an open position.

6. The invention as in claim 4 wherein the valve includes a first actuator stem for axially moving the first seat, the first sensor disposed proximate the actuator stem.

7. The invention as in claim 6 wherein the valve includes a second actuator stem for axially moving the second seat, the second sensor disposed proximate the second actuator stem.

8. The invention as in claim 4 wherein the first sensor comprises:

a sensor housing disposed proximate to the first valve segment defining a bore transverse to the first valve segment;

a limit switch plunger rod having a first portion disposed within the bore of the housing and having a second portion in contacting relation with a portion of the first valve segment, the plunger rod being displaced when the first valve segment is moved; and

a proximity sensor transducer spaced from the limit switch plunger rod portion within the bore of the housing, the proximity sensor transducer detecting transverse movement of the plunger rod and providing the first signal when movement of the plunger rod is detected.

9. The invention as in claim 4 wherein the second sensor comprises:

a sensor housing disposed proximate to the second valve segment defining a bore transverse to the second valve segment;

a limit switch plunger rod having a first portion disposed within the bore of the housing and having a second portion in contacting relation with a portion of the second valve segment, the plunger rod being displaced when the second valve segment is moved; and

a proximity sensor transducer spaced from the limit switch plunger rod portion within the bore of the housing, the proximity sensor transducer detecting transverse movement of the plunger rod and providing the second signal when movement of the plunger rod is detected.

10. A single-axis double-seat valve comprising:

a first valve coupled with a first actuator stem;

a second valve coupled with a second valve stem, the second valve stem being in axial alignment with the first valve stem;

a first sensor for detecting movement of the first actuator stem, the first sensor including a limit switch plunger rod disposed proximate the first actuator stem, and a proximity sensor transducer spaced from the limit switch plunger rod providing a first signal when movement of the plunger rod is detected;

a second sensor for detecting movement of the second actuator stem, the second sensor including a limit switch plunger rod disposed proximate the second actuator stem, and a proximity sensor transducer spaced from the limit switch plunger rod providing a second signal when movement of the plunger rod is detected; and

and a control circuit coupled with the first and second sensors providing a signal indicating a safe position of the valve in response to the first and second signals.