Tank level indicator

• US 8,418,644 B2
• Filed: 06/11/2008
• Issued: 04/16/2013
• Est. Priority Date: 08/14/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Fiedor, Marian, Skricilova, Veronika, Trojak, Pavel
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): COURSON, TANIA C
• Application Number:
  US12/673,501
• Publication Number:
  US 20110192341A1
• Time in Patent Office: 1,770 Days
• Field of Search: 116/227, 333/46, 333/65, 333/661.5, 333/661.7, 333/661.8, 33721-722, 733/13, 732/90.R, 338/33
• US Class Current: 116/227
• CPC Class Codes: G01F 23/36 using electrically actuated indicating means G01F23/38 takes precedence
• CPC Class Codes: G01F 23/363 using electromechanically actuated indicating means

Abstract

Tank level indicators are known, having a sensor housing in which a resistance card having a resistance strip, and a wiper acting with the resistance path and rotatable about an axis of rotation. The variable rotating resistance is encapsulated relative to the fuel in the sensor housing, so that no fuel can enter the sensor housing. It is disadvantageous that the wiper slides dryly against the resistance path, because this gives rise to increased friction and increased wear on the resistance path. The wear particles collect in the sensor housing, and can negatively influence the contact between the wiper and the resistance path. According to the invention, the protection of the tank level indicator relative to particles or ice crystals is improved. It is also ensured that particles or ice crystals that enter the tank level indicator can flow out of the housing of the tank level indicator. According to the invention, the sensor housing having at least one fluid inlet in an upper portion and at least one fluid outlet in a lower portion.

Claims

1. A tank level indicator comprising:

a sensor housing;

a resistance card provided in the sensor housing;

a wiper provided in the sensor housing, the wiper being rotatably supported about an axis of rotation and cooperating in sliding fashion with the resistance card to establish an electrical resistance based on relative positions of the wiper and the resistance card;

at least one fluid inlet in an upper portion of the sensor housing; and

at least one fluid outlet in a lower portion of the sensor housing.

2. The tank level indicator as defined by claim 1, wherein the wiper is coupled to a float that floats on a surface of liquid having a level to be determined by the tank level indicator.

5. The tank level indicator as defined by claim 1, wherein the sensor housing has a mounting part and a cap secured to the mounting part, and the mounting part receives the resistance card and the wiper, and the cap covers the resistance card and the wiper.

6. The tank level indicator as defined by claim 5, wherein the at least one fluid outlet is embodied on the mounting part or on the cap.

7. The tank level indicator as defined by claim 5, wherein the at least one fluid outlet is embodied on a strutlike wall of the cap, which wall extends as far as a sealing edge of the mounting part.

3. A tank level indicator comprising:

a sensor housing;

a resistance card provided in the sensor housing;

a wiper provided in the sensor housing, the wiper being rotatably supported about an axis of rotation and cooperating in sliding fashion with the resistance card;

at least one fluid inlet in an upper portion of the sensor housing;

at least one fluid outlet in a lower portion of the sensor housing; and

means for trapping particles disposed in a region of the at least one fluid outlet.

4. The tank level indicator as defined by claim 3, wherein the means for trapping particles are embodied as peglike, boltlike, or cylindrical.

8. The tank level indicator as defined by claim 3, wherein the means are embodied as flat on one side and have chamfers on the diametrically opposite side.

9. The tank level indicator as defined by claim 3, wherein the sensor housing has a mounting part and a cap secured to the mounting part, and the mounting part receives the resistance card and the wiper, and the cap covers the resistance card and the wiper.

10. The tank level indicator as defined by claim 9, wherein the means for trapping particles are embodied on the mounting part or on the cap.

11. The tank level indicator as defined by claim 3, wherein the wiper is coupled to a float that floats on a surface of liquid having a level to be determined by the tank level indicator.

12. The tank level indicator as defined by claim 3, wherein the wiper slides with respect to the resistance card to establish an electrical resistance based on relative positions of the wiper and the resistance card.

13. A tank level indicator comprising:

a sensor housing;

a resistance card provided in the sensor housing;

a wiper provided in the sensor housing, the wiper being rotatably supported about an axis of rotation and cooperating in sliding fashion with the resistance card;

at least one fluid inlet in an upper portion of the sensor housing; and

at least one fluid outlet in a lower portion of the sensor housing,

wherein the sensor housing has a mounting part and a cap secured to the mounting part, and the mounting part receives the resistance card and the wiper, and the cap covers the resistance card and the wiper.

14. The tank level indicator as defined by claim 13, wherein the at least one fluid outlet is embodied on the mounting part or on the cap.

15. The tank level indicator as defined by claim 13, wherein the at least one fluid outlet is embodied on a strutlike wall of the cap, which wall extends as far as a sealing edge of the mounting part.

16. The tank level indicator as defined by claim 15, wherein the strutlike wall is embodied in the form of part of a circle or in arclike fashion.

17. The tank level indicator as defined by claim 13, wherein the means for trapping particles are embodied on the mounting part or on the cap.

18. The tank level indicator as defined by claim 13, wherein the cap is clipped onto the mounting part.

19. The tank level indicator as defined by claim 13, wherein the wiper is coupled to a float that floats on a surface of liquid having a level to be determined by the tank level indicator.

20. The tank level indicator as defined by claim 13, wherein the wiper slides with respect to the resistance card to establish an electrical resistance based on relative positions of the wiper and the resistance card.