Liquid Level Transducer with Isolated Sensors

• US 20130180329A1
• Filed: 01/17/2012
• Published: 07/18/2013
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Rochester Sensors LLC
• Original Assignee: Rochester Gauges Incorporated
• Inventors: Farmanyan, Gagik, Prieto, Jorge Manuel
• Granted Patent: US 9,116,030 B2
• Time in Patent Office: Days
• US Class Current: 73/317
• CPC Class Codes: G01F 23/38 using magnetically actuated indicating means
• CPC Class Codes: H01H 36/0013 characterised by the co-operation between reed switch and permanent magnet; Magnetic circuits
• CPC Class Codes: H01H 36/0033 Mountings; Housings; Connections
• CPC Class Codes: H01H 36/02 actuated by movement of a float carrying a magnet

Abstract

A transducer for determining the level of liquid within a container includes a mounting head adapted for connection to the container and a sensor assembly adapted to extend into the container. A housing of the sensor assembly has a hollow interior that is isolated from liquid within the container. A plurality of sensor elements are located within the interior. A float rod is pivotally connected to the housing and a float is connected to a distal end of the float rod. An actuator located outside the housing is operatively associated with the float rod for pivotal movement therewith. The actuator is operative to change an electrical state of at least one of the sensor elements to thereby indicate a level condition of the liquid within the container. A snap-fit assembly of the mounting head and sensor assembly is also disclosed.

Claims

1. A transducer for determining the level of liquid within a container, the transducer comprising:

a mounting head adapted for connection to the container; and

a sensor assembly adapted to extend into the container from the mounting head, the sensor assembly comprising;

a housing having an upper portion connected to the mounting head and a lower portion that extends from the upper portion, the lower portion having a hollow interior that is isolated from liquid within the container;

a plurality of sensor elements located within the housing;

a float rod pivotally connected to the housing;

a float connected to a distal end of the float rod to thereby cause pivoting movement of the float rod in response to a change in liquid level within the container; and

an actuator located outside of the housing and operatively associated with the float rod for pivotal movement therewith, the actuator being operative to change an electrical state of at least one of the sensor elements to thereby indicate a level condition of the liquid within the container.

2. A transducer according to claim 1, wherein the sensor elements comprise reed switches and the actuator comprises a magnet that changes one of an open and closed electrical state of the reed switches during pivoting movement of the float rod.

3. A transducer according to claim 2, wherein the sensor assembly further comprises a sensor board located in the hollow interior, the reed switches being mounted on the sensor board in an arcuate pattern.

4. A transducer according to claim 3, wherein a radial center of the arcuate pattern is coincident with a pivot axis of the float rod.

5. A transducer according to claim 4, and further comprising a rod support pivotally connected to the housing at the pivot axis, the float rod extending from the rod support on one side of the pivot axis and the magnet being connected to the rod support on an opposite side of the pivot axis for pivoting movement along an arcuate pathway in alignment with the arcuate pattern.

6. A transducer according to claim 5, wherein the housing further comprises a pivot mount spaced from the hollow interior and coincident with the pivot axis, the rod support being pivotally connected to the pivot mount.

7. A transducer according to claim 6, wherein the mounting head assembly comprises a hollow interior for receiving the upper portion of the housing and a first connecting member for engaging with the housing to thereby connect the mounting head with the housing.

8. A transducer according to claim 7, wherein the housing comprises a second connecting member for engaging with the first connecting member.

9. A transducer according to claim 8, wherein the first connecting member comprises a step that extends into the hollow interior from an inner surface of the mounting head and the second connecting member comprises a resilient tab with an aperture for engaging the step to thereby snap-fit the housing and mounting head together.

10. A transducer according to claim 8, wherein the first connecting member comprises a step that is formed in the inner surface of the mounting head and the second connecting member comprises a resilient tab with a projection for engaging the step to thereby snap-fit the housing and mounting head together.

11. A transducer according to claim 1, wherein the mounting head assembly comprises a hollow interior for receiving the upper portion of the housing and a first connecting member for engaging with the housing to thereby connect the mounting head with the housing.

12. A transducer according to claim 11, wherein the housing comprises a second connecting member for engaging with the first connecting member.

13. A transducer according to claim 12, wherein the first connecting member comprises a step that extends into the hollow interior from an inner surface of the mounting head and the second connecting member comprises a resilient tab with an aperture for engaging the step to thereby snap-fit the housing and mounting head together.

14. A transducer according to claim 13, wherein the first connecting member comprises a step that is formed in the inner surface of the mounting head and the second connecting member comprises a resilient tab with a projection for engaging the step to thereby snap-fit the housing and mounting head together.

18. A transducer according to claim 3, wherein a radial center of the arcuate pattern is coincident with a pivot axis of the float rod.

15. A transducer for determining the level of liquid within a container, the transducer comprising:

a housing adapted to extend into the container, the housing having a hollow interior that is isolated from liquid within the container;

a plurality of sensor elements located within the housing;

a float rod pivotally connected to the housing;

a float connected to a distal end of the float rod to thereby cause pivoting movement of the float rod in response to a change in liquid level within the container; and

an actuator located outside of the housing and operatively associated with the float rod for pivotal movement therewith, the actuator being operative to change an electrical state of at least one of the sensor elements to thereby indicate a level condition of the liquid within the container.

16. A transducer according to claim 15, wherein the sensor elements comprise reed switches and the actuator comprises a magnet that changes one of an open and closed electrical state of the reed switches during pivoting movement of the float rod.

17. A transducer according to claim 16, wherein the sensor assembly further comprises a sensor board located in the hollow interior, the reed switches being mounted on the sensor board in an arcuate pattern.

19. A transducer for determining the level of liquid within a container, the transducer comprising:

a sensor assembly adapted to extend into the container, the sensor assembly including a first housing having a first wall defining a first hollow interior, at least one sensor located within the hollow interior space, and a plurality of tabs extending upwardly from the wall and spaced around a circumference thereof; and

a mounting head connected to the sensor assembly and adapted for connection to the container, the mounting head including, a second housing having a second wall defining a second hollow interior for receiving the first housing and a plurality of connecting members associated with the second wall and corresponding to the plurality of tabs;

wherein the tabs and connecting members are mutually engageable in a snap-fit arrangement to thereby connect the sensor assembly to the mounting head.

20. A transducer according to claim 19, wherein:

each of the tabs includes one of a projection and an aperture; and

each of the connecting members comprises one of a groove and a projection to engage the one of the projection and aperture, respectively.