Liquid level sender assembly

• US 6,658,934 B1
• Filed: 12/04/2001
• Issued: 12/09/2003
• Est. Priority Date: 04/01/1999
• Status: Expired due to Fees

• Current Assignee: Rochester Gauges LLC
• Original Assignee: Rochester Gauges Incorporated
• Inventors: Pattison, Will, Ross, Herbert G. Jr., Housey, Randal L.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): FRANK, RODNEY T
• Application Number:
  US09/937,029
• Time in Patent Office: 735 Days
• Field of Search: 733/05, 733/14, 733/17, 732/90.R
• US Class Current: 73/317
• 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

A liquid level sender assembly constructed to minimize contact distortion and dither. A housing supports a resistive track and a pivot arm is connected to the housing. The pivot arm has a force transmitting member attached which interacts with a boss on a contact carrier which is also pivotably attached to the case. A space is provided in the fit of boss within the force transmitting member which allows the boss to remain in one position when the pivot arm vibrates in small oscillations, but causes the boss to move in response to larger movements of the pivot arm. Contacts on the contact assembly electrically cooperate with the resistive track to provide a variable resistor. The contact carrier receives only force components directed circumferentially about the axis.

Claims

1. A liquid level sender assembly comprising:

a housing;

a resistive track mounted to said housing;

a pivot arm pivotally connected to said housing for rotation about a pivot axis and having a rotational force transmitting member;

a contact carrier pivotally connected to said housing for rotation about said pivot axis and having a rotational force receiving member and a contact assembly, said contact carrier, except for said rotational force receiving member, being isolated from touching said pivot arm;

said rotational force receiving member cooperating with said rotational force transmitting member to receive from said pivot arm only force components directed circumferentially about said pivot axis;

said rotational force transmitting member and said rotational force receiving member dimensioned such that there is a predetermined arc of travel of said rotational force transmitting member which does not result in contact between said rotational force transmitting member and said rotational force receiving member and;

said contact assembly electrically cooperating with said resistive track to generate a variable resistance, said variable resistance varying according to an angular position between said housing and said contact carrier.

2. A liquid level sender assembly according to claim 1, wherein one of said rotational force transmitting member and said rotational force receiving member comprises two spaced-apart surfaces defining a slot having a first width and the other of said rotational force transmitting member and said rotational force receiving member comprises a boss having a second width positioned within said slot, both said widths being measured in a circumferential direction relative to said pivot axis wherein said second width is less than said first width.

3. A liquid level sender assembly according to claim 1, wherein said housing includes two bearings and said pivot arm includes journal portions extending from each side thereof into said bearings.

4. A liquid level sender assembly according to claim 3, wherein at least one of said bearings is a discrete metallic article inserted into said housing.

5. A liquid level sender assembly according to claim 4, wherein said bearing which is a discrete metallic article includes a radial portion and an axial portion, said radial portion being oriented generally parallel to the pivot axis and said axial portion being oriented generally perpendicular to said pivot axis.

6. A liquid level sender assembly according to claim 1, wherein said pivot arm further comprises float arm connection means.

7. A liquid level sender assembly according to claim 6, wherein said float arm connection means comprise:

a float arm attachment passage formed in said pivot arm parallel to, but radially offset from, said pivot axis, said float arm attachment passage being adapted to receive therein one end of a float arm.

8. A liquid level sender assembly according to claim 7, wherein said float arm connection means further comprise:

a plurality of snap members which, through the application of an external force, are deformable from a first configuration to a second configuration to allow positioning of a float arm in a float arm channel, and which, in the absence of said external force, return to said first configuration such that said float arm is retained in said float arm channel.

9. A liquid level sender assembly according to claim 6, wherein said float arm connection means comprise a float arm attachment passage formed in said pivot arm along said pivot axis, said float arm connection passage being adapted to receive therein one end of a float arm.

10. A liquid level sender assembly according to claim 6, wherein said float arm connection means comprise a plurality of snap members which, through the application of an external force, are deformable from a first configuration to a second configuration to allow positioning of a float arm in a float arm channel and which, in the absence of said external force, return to said first configuration such that said float arm is retained in said float arm channel.

11. A liquid level sender assembly comprising:

a housing defining an annular boss about a pivot axis and having inside and outside surfaces;

a resistive track mounted to said housing;

a pivot arm pivotally mounted for rotation about the said pivot axis and having a portion thereof rotationally associated with either said inside surface or said outside surface of said annular boss and having a rotational force transmitting member;

a contact carrier pivotally mounted for rotation about said pivot axis and having a portion thereof rotationally associated with the side of said annular boss opposite the side of said annular boss rotationally associated with said pivot arm, said contact carrier having a rotational force receiving member and a contact assembly, said contact carrier, except for said rotational force receiving member, being isolated from touching said pivot arm;

said rotational force receiving member cooperating with said rotational force transmitting member to receive from said pivot arm only force components directed circumferentially about said pivot axis;

said contact assembly electrically cooperating with said resistive track to generate a variable resistance, said variable resistance varying according to an angular position between said housing and said contact carrier.

12. A liquid level sender assembly according to claim 11, wherein one of said rotational force transmitting member and said rotational force receiving member comprises two spaced-apart surfaces defining a slot having a first width and the other of said rotational force transmitting member and said rotational force receiving member comprises a boss having a second width positioned within said slot, both said widths being measured in a circumferential direction relative to said pivot axis.

13. A liquid level sender assembly according to claim 12, wherein said second width is less than said first width.

14. A liquid level sender assembly according to claim 11, wherein said housing includes a bearing interposed between said pivot arm and the surface of said annular boss to which it is rotationally associated.

15. A liquid level sender assembly according to claim 14, wherein said pivot arm is rotationally associated with the inside surface of said annular boss and said contact carrier is rotationally associated with said outside surface of said boss.

16. A liquid level sender assembly according to claim 15, wherein said bearing which is a discrete metallic article includes a radial portion and an axial portion, said radial portion being oriented generally parallel to the pivot axis and said axial portion being oriented generally perpendicular to said pivot axis.

17. A liquid level sender assembly according to claim 11, wherein said pivot arm further comprises float arm connection means.

18. A liquid level sender assembly according to claim 17, wherein said float arm connection means comprise:

a float arm attachment passage formed in said pivot arm parallel to, but radially offset from, said pivot axis, said float arm attachment passage being adapted to receive therein one end of a float arm.

19. A liquid level sender assembly according to claim 18, wherein said float arm connection means further comprise:

a plurality of snap members which, through the application of an external force, are deformable from a first configuration to a second configuration to allow positioning of a float arm in a float arm channel, and which in the absence of said external force, return to said first configuration such that said float arm is retained in said float arm channel.

20. A liquid level sender assembly according to claim 17, wherein said float arm connection means comprise a float arm attachment passage formed in said pivot arm along said pivot axis, said float arm connection passage being adapted to receive therein one end of a float arm.

21. A liquid level sender assembly according to claim 17, wherein said float arm connection means comprise a plurality of snap members which, through the application of an external force, are deformable from a first configuration to a second configuration to allow positioning of a float arm in a float arm channel and which, in the absence of said external force, return to said first configuration such that said float arm is retained in said float arm channel.