The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Oct. 26, 1999

Filed:

Nov. 26, 1997
Applicant:
Inventors:

Sanjay Srinivasan, Midlothian, VA (US);

David Warren Smith, Richmond, VA (US);

John P Sunne, Midlothian, VA (US);

Assignee:

Ethyl Corporation, Richmond, VA (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C10M / ; C10M / ;
U.S. Cl.
CPC ...
508188 ; 508228 ; 508294 ; 508428 ; 252 785 ;
Abstract

Automatic transmission fluids are described which contain a dispersant having a nitrogen to phosphorus mass ratio between about 3:1 and about 10:1, and at least one friction modifier. The use of dispersants having a nitrogen to phosphorus mass ratio between about 3:1 and about 10:1 provides automatic transmission fluids which exhibit good anti-shudder properties as well as a higher mid-point torque, a higher static torque in shifting clutch applications and better frictional durability as compared to similar automatic transmission fluids which contain dispersants having a nitrogen to phosphorus mass ratio of less than 3:1.


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