Baldwin-Lima-Hamilton Corp. v. Tatnall Meas. Sys. Co.

• Decision Date: 26 December 1958
• Docket Number: Civ. A. No. 23505.
• Citation: Baldwin-Lima-Hamilton Corp. v. Tatnall Meas. Sys. Co., 169 F.Supp. 1, 120 USPQ 34 (E.D. Pa. 1958)
• Parties: BALDWIN-LIMA-HAMILTON CORPORATION and Edward E. Simmons, Jr., Plaintiffs, v. TATNALL MEASURING SYSTEMS COMPANY and The Budd Company, Defendants.
• Court: U.S. District Court — Eastern District of Pennsylvania

169 F. Supp. 1

BALDWIN-LIMA-HAMILTON CORPORATION and Edward E. Simmons, Jr., Plaintiffs, v.TATNALL MEASURING SYSTEMS COMPANY and The Budd Company, Defendants.

Civ. A. No. 23505.

United States District Court E. D. Pennsylvania.

December 1, 1958.

Reargument Denied December 26, 1958.

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Arthur Littleton and Robert C. McAdoo(of Morgan, Lewis & Bockius), Philadelphia, Pa., Walter J. Blenko, Sr., and Walter J. Blenko, Jr.(of Blenko, Hoopes, Leonard & Buell), Pittsburgh, Pa., for plaintiffs.

Edward A. Hathaway, Waltham, Mass., for plaintiffBaldwin-Lima-Hamilton Corp.

Joseph W. Swain, Jr., and Thomas N. O'Neill, Jr.(of Montgomery, McCracken, Walker & Rhoads), Philadelphia, Pa., Dexter N. Shaw and John C. Dorfman(of Howson & Howson), Philadelphia, Pa., for defendants.

STEEL, District Judge.

Simmons, a patentee, and his licensee, Baldwin-Lima-Hamilton Corporation(hereinafter "Baldwin") have sued The Budd Company(hereinafter "Budd") and its wholly owned subsidiary, Tatnall Measuring Systems Company(hereinafter "Tatnall"), for infringement of Claims 1, 2, 3, 4, 5, 7, 8 and 9 of PatentNo. 2,292,549(hereinafter "Simmons patent").The patent relates to a gage for measuring strain in materials.

Baldwin has marketed "bonded wire strain gages" under the Simmons patent since 1940.Without license from plaintiffs, Tatnall has manufactured, used and sold "foil type" strain gages and Budd has used "foil type" strain gages manufactured by Tatnall.The "foil gages", plaintiffs charge, infringe the Simmons patent.

In defense the defendants have pleaded (a) noninfringement; (b) invalidity because of (i) anticipation, (ii) lack of invention and obviousness, (iii) inadequacy of patent description, and (iv) inclusion of new matter in amendment to application; and (c) unclean hands because of (i) fraud on the Patent Office, and (ii) patent misuse.

Jurisdiction exists under 28 U.S.C. § 1338(a).

Subject Matter of Simmons Patent

The load or force which is applied to a body is known as "stress".It may be expressed in terms of pounds per square inch.When a body is subjected to stress, it is deformed to some extent.The deformation is known as "strain".It may be expressed in terms of inches of strain per inch of length.

In any material used for engineering purposes, the stress must be kept within safe limits to prevent failure.Well-known and determinable relationships exist between stress and strain in engineering materials.Where the strain in a material is known at a given point, the stress at that point can be ascertained.

The purpose of the Simmons gage is to measure strain.The gage employs the principle discovered by Lord Kelvin more than a century ago that the electrical resistance of materials which are electrically conductive varies with the strain thereof.If the material is stretched, its resistance will increase; if it is compressed, its resistance will decrease.This property is referred to in the Simmons patent as "electrical strain sensitivity".

Claim 5 contains three elements: (i) a test body whose strain is to be measured, (ii) a continuous metallic filament of solid electrical conducting material whose electrical resistance varies in accordance with changes in strain in the filament, and (iii) a means for adhesively bonding the filament in an untaut condition throughout its effective length to the body to be tested so that the filament forms a completely unitary part of the test body¹.When a filament described by Simmons is bonded to a test body as Simmons has directed, any deformation of the test body will cause a corresponding deformation in the filament (for instance, a lengthening of the test body will cause a commensurate lengthening of the filament) and the electrical resistance of the filament will vary as deformation changes occur.By an appropriate electrical circuit (not subject to the Simmons patent) the variance in the electrical resistance of the filament can be recorded.By comparing such resistance changes with the predetermined electrical strain sensitivity of the filament, the strain in the test body can be ascertained.

Infringement

35 U.S.C. § 271(a) defines infringement as the unauthorized making, using or selling of a "patented invention".The critical question, therefore, is what the Simmons patented invention is, and whether the foil gages manufactured by Tatnall embody it.

The sketches below have been agreed upon by counsel as magnified versions of the Baldwin gage (wire type) and the Tatnall gage:

In the Simmons bonded wire gage the electrical current flows from one end of the wire to the other, and the entire length of the wire, wound back and forth, is the gage.In the foil gage of defendants the current flows from one lead connection tab through the first straight length of foil, then across the enlarged connecting portion of foil, then down through the next straight length of foil, then across the next enlarged connecting portion of foil, and so on, to the other lead connection tab.As in the Simmons gage, the foil gage is bonded to the specimen to be tested, thereby becoming a slave, as it were, of the test body, and deforming precisely as the test body deforms.With the occurrence of deformations in the foil measurable variations take place in the electrical resistance of the foil.The Simmons wire strain gage operates on this same principle.

Defendants contend that the invention of Simmons is limited to a "filament" in the form of a wire, that the foil of defendants' gage is neither a wire nor a filament, and that therefore the foil gage does not embody Simmons' invention.Plaintiffs assert that Simmons did not limit his invention to a filament which was a wire but intended filament to have a connotation sufficiently broad to comprehend the foil conducting elements of the defendants' gage.

Claim 5 is not in words restricted to a filament in the form of a wire.But the claims of a patent need not be read in a vacuum.For purposes of determining whether an accused device is an infringement, the claims of a patent are to be interpreted not only in the light of the specification but also with reference to the file wrapper history.Mas v. Owens-Illinois Glass Co., D.C.D.N.J.1954, 122 F.Supp. 582, 583;affirmed, 3 Cir., 1955, 222 F.2d 889;certiorari denied350 U.S. 1016, 76 S.Ct. 661, 100 L. Ed. 875;rehearing denied, 1946, 351 U.S. 943, 76 S.Ct. 838, 100 L.Ed. 1470.Here, both the specifications and the representations which Simmons made to the Patent Office during the patent prosecution establish that the filament which Simmons claimed as an element of his invention was a filament in the form of a wire.

Thus, Simmons says in his specification, "To determine the strain * * * I employ my improved strain sensitive electrical means consisting of a filament of very fine metallic wire"².At other places in the specification the word "filament" is used in conjunction with "wire"; as for example, "wire filament"³ and "wire forming a filament"⁴.

The file wrapper discloses that Simmons used the words "wire filament" at least thirteen times and the word "wire" no less than thirty-eight times.Nowhere did Simmons define the word "filament" in any other way.At one point Simmons said, "* * * applicant's filament is a continuously solid metallic wire element * * *"⁵.In distinguishing the Lorig patent which the Patent Office had cited as an anticipation, Simmons pointed out that Lorig had no thought of using "a strain sensitive filament formed of a continuously solid metallic wire * * *"⁶, thereby inferentially indicating that the Simmons patent did call for a "metallic wire".

That Simmons limited his electrical strain sensitive element to "fine metallic wire" is conclusively settled by the affidavit which Simmons filed in the Patent Office on August 19, 1941.There Simmons described his "invention" as follows:

"A continuously solid fine metallic wire was bonded throughout its effective length to a member subject to strain and this wire was connected to an electrical circuit whereby a change of strain in the wire was accompanied by a predetermined change of electrical resistance of the wire.The change in electrical resistance was measured by the electrical circuit, thereby indicating the amount of strain."⁷

If "filament" in the Simmons patent is construed to mean wire, then the foil elements of defendants' gages are outside the literal terms of the claims.And even though filament is given some latitude of meaning beyond that of wire, still in its primary sense, it means "a thread or a slender, thread-like object * * *".Webster's New International Unabridged Dictionary.

Dimensionally the foil elements of defendants' gage are completely lacking in the "thread-like" characteristic of a filament.In defendants' 130-1 gage, the thickness of the foil is approximately .000150 inches and the width of straight lengths is .0096 inches, giving a ratio of width to thickness of approximately 64 to 1.In defendants' 141 gage, the thickness of the foil is the same and the width is .0062, giving a ratio of width to thickness of approximately 41 to 1.The foil elements can be more accurately described as ribbons or strips than filaments.

Accordingly, defendants have not been guilty of a literal infringement of Simmons' patent.In spite of this fact, a comparison of defendants' foil gage with plaintiffs' wire gage discloses that the distinctions between the two are colorable only.Uncontroverted testimony by plaintiffs' expert, Dr. Ruge, as well as a courtroom demonstration which stands unassailed, establish that the two devices do the same work in substantially the same way and accomplish the same result.The devices in the eyes of the law are therefore the same under the doctrine of equivalents which had its origin in Winans v. Denmead, 1854, 15 How. (56 U.S.) 329, 330, 342-343, 14 L.Ed. 717 more than...