Limit switch for rising stem gate valves

Patent metadata

Field	Value
Publication number	US-10677374-B2
Application number	US-201816124662-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Aug 25, 2017
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A limit switch assembly, for a rising-stem valve having a stem with a diameter and a groove marking a desired stem position, includes an actuator arm having an inner end and an outer end. The inner end of the actuator arm forms a follower. A radius washer is mounted to the outer end of the actuator arm. An electrical switch has an operating lever and is mounted adjacent to the outer end of the actuating arm such that when the actuator arm is in an outward position the radius washer moves the operating lever, operating the electrical switch. When the actuator arm is in an inward position the radius washer does not move the operating lever and the electrical switch is not operated. A bias spring biases the actuating arm toward the inward position.

First claim

What is claimed is:

1. A limit switch assembly for a rising-stem valve having a stem with a diameter and a groove marking a desired stem position, comprising:
an actuator arm having an inner end and an outer end, the inner end of the actuator arm forming a follower;
an operating lever actuator element mounted to the outer end of the actuator arm, the operating lever actuator element having a curved surface;
an electrical switch having an operating lever, the electrical switch mounted adjacent to the outer end of the actuator arm such that when the actuator arm is in an outward position the curved surface of the operating lever actuator element contacts and retains the operating lever in a first position such that the electrical switch is in a first state of operation, and when the actuator arm is in an inward position the curved surface of the operating lever is in a second position such that the electrical switch is in a second state of operation; and
a bias spring biasing the actuator arm toward the inward position.

2. The limit switch assembly of claim 1 , wherein the first state of operation is a state of activation, and the second state of operation is a state of inactivation.

3. The limit switch assembly of claim 1 , further comprising a base plate having a plurality of feet to mount the base plate on an exterior of a valve yoke.

4. The limit switch assembly of claim 1 , further comprising a base plate configured to mount to an exterior of a valve yoke, the base plate having a wedge shape.

5. The limit switch assembly of claim 1 , further comprising a mounting boss and a mounting plate, the mounting boss configured to be secured to an inside of a valve yoke, to extend through a side of the valve yoke, and to attach to the mounting plate, the mounting plate configured to attach to an exterior side of the valve yoke.

6. The limit switch assembly of claim 1 , further comprising an adjustment nut mounted to the outer end of the actuator arm adjacent the operating lever actuator element, the operating lever actuator element and the nut configured to be adjusted along a longitude of the actuator arm to change a space between the operating lever actuator element and the operating lever.

7. A limit switch assembly for a rising-stem valve having a stem with a diameter and a groove marking a desired stem position, comprising:
an actuator arm having an inner end and an outer end, the inner end of the actuator arm forming a follower;
a radius washer mounted to the outer end of the actuator arm, the radius washer having a curved surface;
an electrical switch having an operating lever, the electrical switch mounted adjacent to the outer end of the actuator arm such that when the actuator arm is in an outward position the curved surface of the radius washer contacts and moves the operating lever, operating the electrical switch, and when the actuator arm is in an inward position the curved surface of the radius washer does not contact or move the operating lever and the electrical switch is not operated; and
a bias spring, biasing the actuator arm toward the inward position.

8. The limit switch assembly of claim 7 , wherein the electrical switch is a single-pole double-throw switch.

9. A rising-stem valve comprising:
a valve body including a channel therein;
a gate fitting in the channel such that when the gate is in a lowered position in the channel, the gate blocks water flow through the valve body, and when the gate is in a raised position water can flow through the valve body;
a stem with a diameter and a locator groove marking a desired stem position, the stem having a lower end coupled to the gate, an upper end having a threaded portion and a non-threaded portion between the threaded portion and the lower end;
a yoke having a lower end mounted on the valve body, a top having a yoke nut through which the threaded end of the stem is threaded such that rotating the stem around the stem axis relative to the yoke nut raises or lowers the stem, the top further having a side with an exterior surface;
a limit switch assembly mounted to the exterior surface of the side of the yoke, the limit switch including:
an actuator arm having an inner end and an outer end, the inner end of the actuator arm forming a follower;
a radius washer mounted to the outer end of the actuator arm, the radius washer having a curved surface;
an electrical switch having an operating lever, mounted adjacent to the outer end of the actuator arm, such that when the actuator arm is in an outward position the curved surface of the radius washer moves the operating lever, operating the electrical switch, and when the actuator arm is in an inward position the curved surface of the radius washer does not move the operating lever and the electrical switch is not operated; and
a bias spring, biasing the actuator arm toward the inward position, such that the follower is biased into contact with the stem,
the locator groove formed around the non-threaded portion of the stem at a location selected such that when the gate is in a desired position, the follower of the limit switch, biased by the bias spring, drops into the groove, moving the actuator arm to an inward position at which the curved surface of the radius washer does not move the operating lever, such that the electrical switch is not operated.

10. The valve of claim 9 , wherein the exterior surface includes a platform formed into the side of the yoke, and wherein the limit switch is mounted on the platform.

11. The valve of claim 9 , in which the limit switch assembly further comprises a base plate having a plurality of feet to mount the base plate on the exterior surface of the side of the yoke.

12. The valve of claim 9 , wherein the electrical switch is a single-pole double-throw switch.

13. The valve of claim 9 , wherein the desired position is a position in which the valve is open.

14. The valve of claim 9 , further comprising an adjustment nut threaded onto the outer end of the actuator arm to retain the radius washer on the actuator arm and by which rotation of the adjustment nut adjusts a position of the radius washer along a longitude of the actuator arm.

15. The valve of claim 9 , further comprising a base plate mounted to the exterior surface of the side of the yoke, the base plate having a wedge shape.

16. The valve of claim 9 , further comprising a mounting boss extending through the side of the yoke.

17. The limit switch assembly of claim 7 , further comprising a base plate having a plurality of feet to mount the base plate on an exterior of a valve yoke.

18. The limit switch assembly of claim 7 , further comprising a base plate configured to mount to an exterior of a valve yoke, the base plate having a wedge shape.

19. The limit switch assembly of claim 7 , further comprising an adjustment nut threaded onto the outer end of the actuator arm to retain the radius washer on the actuator arm and by which rotation of the adjustment nut adjusts a position of the radius washer along a longitude of the actuator arm.

20. The limit switch assembly of claim 7 , further comprising a mounting boss and a mounting plate, the mounting boss configured to be secured to an inside of a valve yoke, to extend through a side of the valve yoke, and to attach to the mounting plate, the mounting plate configured to attach to an exterior side of the valve yoke.

Assignees

• Kennedy Valve Company

Inventors

• Kennedy Paul

Classifications

• F16K37/0041 Primary

  for measuring valve parameters (F16K37/0033 takes precedence) · CPC title

• F16K3/00

  Gate valves or sliding valves, i.e. cut-off apparatus with closing members having a sliding movement along the seat for opening and closing (F16K5/00 takes precedence; in barrages or weirs E02B8/04) · CPC title

• F16K27/044

  slide valves with flat obturating members · CPC title

• Y10T137/8242

  Electrical · CPC title

• H01H3/0206

  Combined operation of electric switch and of fluid control device · CPC title