311 F.3d 1116 (Fed. Cir. 2002), 01-1417, Verve, LLC v. Crane Cams, Inc.

Docket Nº:01-1417.
Citation:311 F.3d 1116
Party Name:65 U.S.P.Q.2d 1051 VERVE, LLC, Plaintiff-Appellant, v. CRANE CAMS, INC., Crower Cams & Equipment Company, Inc., Trend Products, Inc., and Competition Cams, Inc., Defendants-Appellees, and Manton Racing Products, Defendant-Appellee.
Case Date:November 14, 2002
Court:United States Courts of Appeals, Court of Appeals for the Federal Circuit

Page 1116

311 F.3d 1116 (Fed. Cir. 2002)

65 U.S.P.Q.2d 1051

VERVE, LLC, Plaintiff-Appellant,


CRANE CAMS, INC., Crower Cams & Equipment Company, Inc., Trend Products, Inc., and Competition Cams, Inc., Defendants-Appellees, and

Manton Racing Products, Defendant-Appellee.

No. 01-1417.

United States Court of Appeals, Federal Circuit

November 14, 2002

Page 1117

John A. Artz, Artz & Artz, P.C., of Southfield, MI, argued for plaintiff-appellant. With him on the brief was John S. Artz, and Robert P. Renke.

Geoffrey R. Myers, Hall, Priddy, Myers & Vande Sande, of Potomac, MD, argued for defendants-appellees. Of counsel on the brief was James E. Wynne, Butzel Long, of Detroit, Michigan.

Before NEWMAN, LOURIE, and CLEVENGER, Circuit Judges.

PAULINE NEWMAN, Circuit Judge.

Verve, LLC, appeals the decision of the United States District Court for the Eastern District of Michigan, 1 granting summary judgment that claims 1, 6, and 13 of United States Patent No. 4,850,315 (the '315 patent) are invalid. We reverse the

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judgment with respect to anticipation, vacate with respect to indefiniteness, and remand for further proceedings.


The '315 patent describes and claims improved push rods for internal combustion engines. Push rods are used to actuate rocker arms which open and close the intake and exhaust valves of cylinders of engines designed for their use. In such engines the push rods ride on cam followers, which are raised and lowered by the camshaft as it rotates. As engine speeds have increased so have the number of piston strokes, requiring a corresponding increase in the number of valve openings and closings; this in turn increases the movement of and forces on the push rods. Stronger push rods became necessary and, to lighten their weight, hollow push rods were developed. However, there was a need for stronger and stiffer rods that could be manufactured from a single piece of metal without the need for inserts or other supporting structure.

The '315 patent claims a hollow push rod whose overall diameter is larger at the middle than at the ends and that has substantially constant wall thickness throughout the rod, and rounded seats at the tips. This novel shape is said to provide the advantages of increased strength and stiffness, permitting higher engine speeds and greater valve train forces. The '315 patent illustrates the invention as follows:

(Image Omitted)

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As seen in the drawings and as required by the claims, the push rod 10"' is configured whereby the outer diameter of the middle portion is larger than the outer diameter of the end portions 18 and 20. The end portions have a rounded tip 52 forming a seat, that engages a pocket of a cam follower at one end and a pocket of a rocker arm at the other end. The shape of the push rod provides increased strength, and because it is hollow it is relatively light. Since the rounded tips are integrally formed, there are no problems with disengagement and the rod is relatively inexpensive to manufacture. Claim 1 is representative:

1. A push rod for an internal combustion engine comprising:

a single piece of metal in the form of an elongated hollow tube having a middle portion, first and second end portions and rounded seats at the tips thereof,

said middle portion having a larger outer diameter than the end portions,

and said tube having substantially constant wall thickness throughout the length of the tube and the tips thereon.

The district court granted summary judgment of invalidity on two grounds: that the claims are indefinite, and that the claimed invention is anticipated.


The district court found that the expression "substantially constant wall thickness" in the claims is not supported in the specification and prosecution history by a sufficiently clear definition of "substantially." The court explained:

In this case, judging by the intrinsic record, the meaning of "substantially" constant wall thickness is unclear. While not the basis of this court's decision, the ambiguity of this term was demonstrated at the motion hearing by the plaintiff's willingness to include great variations in wall thickness within the parameters of "substantially" constant wall thickness in a manner that renders them without meaning.

The court further explained that the word "substantially" was at issue because the parties disputed the scope of "substantially constant wall thickness," and that liability for infringement depends on whether "substantially" embraces the accused push rods. The court recognized that the usage "substantially" may be adequately definite in some cases, but ruled that in this case it...

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