Darlene M. Collett appeals the adverse decision of the United States District Court for the Eastern District of Texas,
*fn1 holding, in a bench trial, that the patent in suit is not infringed under the doctrine of equivalents, and is invalid for violation of 35 U.S.C. �102(b), the on-sale bar. United States Patent No. 4,889,025, inventor Kenneth L. Collett, issued December 26, 1989 upon an application filed May 23, 1988. A reexamination certificate, B1 4,889,025, issued December 3, 1996. Reexamined claim 1 is representative:
Rex 1. An improved cutting tooth for a circular saw of the type commonly used to cut raw logs comprising a crescent shaped steel bit and a wedge shaped cutting tip affixed to an upper portion of said bit wherein said cutting tip is composed of high impact resistant carbide alloy consisting essentially of a mixture of 83.5% tungsten carbide, 16% cobalt and 0.5% tantalum carbide, said bit being disposed in said circular saw so that said cutting tip has a hook with a positive angle of about 37E with respect to the radius of said saw, said cutting tip has an inner end which is received in a slot in said bit, said crescent shaped steel bit has an outer edge and an inner edge, said outer edge comprises a curved portion and a flattened portion, said inner edge of said bit comprises a projection extending in a direction away from said outer edge, said projection having a forward edge on one side with said slot formed therein and a concave edge formed on a side of said projection opposite said forward edge for receiving a portion of a shank for holding said bit to said circular saw, said slot comprising first and second spaced apart edges which face each other and a transverse edge extending between said first and second edges with said first edge facing in the direction of said outer edge of said bit and said second edge comprising an elongate slot edge which joins said flattened portion of said bit such that said elongate slot edge and said flattened portion of said bit define an acute angle, said first edge of said slot being much shorter than said second edge, said cutting tip having its said inner end located and secured in said slot with an elongated tip portion located adjacent to said second edge and a cutting tip outer edge which joins said elongated tip portion defining an obtuse angle therebetween, said cutting tip having a cutting face opposite said elongated tip portion with a substantial portion of said cutting face being located outside of said slot such that an inner edge of said tooth is defined by a portion of said cutting face of said tip, said forward edge and said concave edge.
Infringement
