ULTRASONIC LEVEL SENSOR FOR AERATED FLUIDS

• US 20130220012A1
• Filed: 10/20/2011
• Published: 08/29/2013
• Est. Priority Date: 11/18/2010
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Knowles, Terence J., Truesdale, Brian J., Albrecht, Kenneth A., Bremigan, Charles F. III
• Granted Patent: US 10,551,238 B2
• Time in Patent Office: Days
• US Class Current: 73/292
• CPC Class Codes: G01F 23/296 Acoustic waves
• CPC Class Codes: G01F 23/2967 for discrete levels

Abstract

An ultrasonic sensor for detecting the presence or absence of an aerated fluid includes a probe having a first solid portion and a second hollow portion. The probe has a closed end at the hollow portion. The solid portion and the hollow portion define an interface therebetween. A transducer element is mounted to the probe at about the solid portion. The transducer element is configured to transmit an ultrasonic signal through the solid portion into the hollow portion and to receive reflections of the ultrasonic signal to determine the presence or absence of a fluid and/or an aerated fluid.

Claims

1. An ultrasonic sensor for detecting the presence or absence of an aerated fluid, comprising:

a probe having a first solid portion and a second hollow portion, the probe having a closed end at the hollow portion, the solid portion and the hollow portion defining an interface therebetween;

a transducer element operably connected to the probe at about the solid portion, the transducer element configured to transmit an ultrasonic signal through the solid portion into the hollow portion, the transducer element further configured to receive reflections of the ultrasonic signal to determine the presence or absence of a fluid and/or an aerated fluid.

2. The ultrasonic sensor of claim 1 wherein a cap is positioned at about an end of the hollow portion to define the closed end.

3. The ultrasonic sensor of claim 1 wherein the transducer element is a compression-type transducer.

4. The ultrasonic sensor of claim 1 including a flange at an end of the solid portion distal from the hollow portion.

5. The ultrasonic sensor of claim 1 including a temperature sensor operably connected to the probe.

6. The ultrasonic sensor of claim 1 wherein the probe is formed as a rod.

7. The ultrasonic sensor of claim 1 including a ring disposed on an outer surface of the rod at the interface between the solid portion and the hollow portion.

8. The ultrasonic sensor of claim 1 including a housing, wherein the solid portion of the probe is mounted at least in part within the housing, and wherein the hollow portion of the probe depends from and is outside of the housing.

9. The ultrasonic sensor of claim 1 wherein the probe is formed from aluminum.

10. The ultrasonic sensor of claim 9 wherein the probe has a diameter of about 0.3125 inches and the hollow portion has a wall thickness of about 0.030 inches.

11. The ultrasonic sensor of claim 1 wherein the probe is formed with the first and second portions integral with one another.

12. The ultrasonic sensor of claim 11 wherein the probe is formed as a rod, and wherein the second portion is a hollowed out portion of the rod.

13. The ultrasonic sensor of claim 8 wherein the probe is mounted in the housing, isolated from the housing.

14. The ultrasonic sensor of claim 13 including one or more isolating elements between the housing and the probe.

15. The ultrasonic sensor of claim 14 wherein the isolating elements are O-rings.

16. The ultrasonic sensor of claim 8 including a circuit board in the housing, wherein the transducer is electrically connected to the circuit board.

17. The ultrasonic sensor of claim 16 including one or more springs for electrically connecting the transducer to the circuit board.

18. The ultrasonic sensor of claim 1 wherein the probe is formed from multiple sections joined to one another.

19. The ultrasonic sensor of claim 8 wherein the probe is formed from multiple sections at a joint, and wherein the joint is positioned within the housing.

20. The ultrasonic sensor of claim 19 including one or more seals between the probe and the housing and wherein the joint is positioned between the seals and the transducer element.