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.
Patent No.:
Date of Patent:
Jul. 25, 2000
Filed:
Jan. 09, 1998
Scott A McLaughlin, Evanston, IL (US);
Brian T Jordan, Chicago, IL (US);
Kevin F Wesling, Lombard, IL (US);
John D Cheever, Chicago, IL (US);
SRAM Corporation, Chicago, IL (US);
Abstract
A parallelogram link mechanism of a bicycle derailleur has a coil spring tensioned from a first axis of the parallelogram to another axis thereof that is diametrically opposed to the first axis. The coil spring exerts a primary spring force against the rider-supplied derailleur actuation force throughout the actuation range of the derailleur. A secondary member exerts a secondary force throughout a portion of the actuation range of the derailleur, producing a substantially constant resultant actuation force experienced by the rider. The secondary member can take various forms, including an abutment member which selectively abuts the coil spring at an angle to the spring axis; a second spring internal to the first; a member which is attached to spaced-apart coils of the coil spring to limit their linear expansion; and an internal member which limits constriction of a segment of the coil spring inwardly toward the spring axis.