Esco Corp. v. Hensley Equipment Co.

251 F. Supp. 631, 148 U.S.P.Q. (BNA) 600, 1966 U.S. Dist. LEXIS 10439, 1966 Trade Cas. (CCH) 71,797
CourtDistrict Court, N.D. Texas
DecidedFebruary 18, 1966
DocketCiv. A. No. 3-1010
StatusPublished
Cited by3 cases

This text of 251 F. Supp. 631 (Esco Corp. v. Hensley Equipment Co.) is published on Counsel Stack Legal Research, covering District Court, N.D. Texas primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Esco Corp. v. Hensley Equipment Co., 251 F. Supp. 631, 148 U.S.P.Q. (BNA) 600, 1966 U.S. Dist. LEXIS 10439, 1966 Trade Cas. (CCH) 71,797 (N.D. Tex. 1966).

Opinion

HUGHES, District Judge.

FINDINGS OF FACT

1. This is an action for infringement of U. S. Patent No. 2,919,506, relating to excavating teeth, which are wedge-shaped projections installed on the forward edge of a dipper or bucket to facilitate penetration of the earth. The complaint charges Defendant with infringe[633]*633ment by making and selling tooth points covered by the Letters Patent. Defendant denies validity of the patent and infringement, and has filed four counterclaims, seeking a declaratory judgment that U. S. Patents 2,919,506, 3,026,947 and 3,079,710 are invalid and not infringed by Defendant alleging violation of antitrust laws, misuse and unfair competition by Plaintiff.

2. The jurisdiction of this Court is predicated upon the fact that this is an action arising under the Patent Laws of the United States.

3. The Plaintiff is a corporation organized and existing under the laws of the State of Oregon and has its principal place of business in Portland, Oregon. It manufacturers and sells points and adapters for dragline buckets, backhoes, and shovel dippers in construction, mining and other earthmoving jobs. Plaintiff is the owner of the entire right, title, and interest in and to U. S. Patent No. 2,919,506.

4. The Defendant is Hensley Equipment Co., Inc., a corporation organized and existing under the laws of the State of Texas, with its principal place of business in Dallas, Texas. Defendant is also engaged in the business of manufacturing and selling points and adapters for heavy equipment.

5. U. S. Patent No. 2,919,506 was issued on January 5, 1960, upon the application of Paul V. Larsen, application for which was filed April 21,1958.

6. The invention relates to an excavating tooth which is installed on the forward edge of a dipper or bucket. The main feature of all claims is that at least one of the upper and lower bearing surfaces of the point of the tooth is a “surface of revolution” having a vertical axis.

7. For the last 20 years excavating teeth have been made in two parts, an adapter secured to the leading edge of the bucket and a replaceable point secured to the adapter by means of a removable locking pin. Without these penetrating teeth, the leading edge of the bucket would have to withstand the shock of encountering rocks. This would mean expensive repairs as contrasted to merely replacing the projection itself.

8. In the type of adapter and point commonly used previously, the adapter and point had angularly related flat surfaces. In the swinging movement of the tooth point on the adapter nose under impact with rocks, contact between the flat angular mating surfaces of the point and nose was reduced to a small, limited area. This resulted in localized stress on the point and nose in that area. The result of this action was to deform the hard-to-remove adapter so as to make it unable to receive a new point.

9. In order to prevent deformation of the adapter, there was need for the nose and point members to have surfaces which remain in contact during lateral movement of one of the members with respect to the other, while at the same time providing a sturdy interlock between the members.

10. The invention in suit departs from the flat angular contacting nose and point socket surfaces and uses conical surfaces of revolution having a vertical axis, thus enabling the parts to move in an arc relative to each other with the bearing surfaces of the two members substantially in full contact.

11. As stated in the patent, one object is to provide a combination of nose and socket elements united by keys or other means whereby the parts may swing relative to each other to a limited extent while at the same time providing wide areas of contact between the members during each portion of such travel so that a large bearing surface is provided between the members under heavy load and irrespective of the relative position of the two members.

12. The excavating teeth with the conical bearing surface of the invention in suit have enjoyed substantial commercial success and sales have materially increased. Caterpillar Tractor Company, a well-known manufacturer of excavating equipment, was licensed under the patent and Esco received the 1962 Mining World award for “achievement in equipment [634]*634development aiding the technological advancement of the mining industry.”

13. Claims 1 and 3 are directed to the combination of the point and adapter. Claim 1 reads: “1. A supporting structure for an excavating tooth, and the like, subject to stresses tending to produce sideways movement, comprising a tapered nose member and a socket member receiving said nose member, said socket member having confronting upper and lower interior bearing surfaces fitting corresponding upper and lower exterior-, bearing surfaces on said nose member, said bearing surfaces being surfaces of revolution having a common axis extending vertically of said nose, and means on said axis interconnecting said members for limited relative rotation of one of said members in a sideways direction about said axis, whereby said bearing surfaces remain in fitting contact during said sideways movement of one of said members.”

14. Claims 8, 20 and 28 are directed to the replaceable excavating tooth point. Claim 8 reads: “8. A replaceable excavating tooth point, comprising a spike portion integral with and projecting forwardly from a supporting portion, said supporting portion having top and bottom bearing surfaces adapted to engage longitudinally-extending top and bottom bearing surfaces on a tooth point support, said bearing surfaces on said tooth point being generally convergent in a direction longitudinally of the tooth point, and said bearing surfaces being surfaces of revolution having a common axis of generation adjacent the rear extremity of said supporting portion and extending in an approximately vertical direction with respect to said top and bottom surfaces.”

15. Hensley Equipment Co., Inc. supplied Texas Steel Company with a model of an Esco point having conical surfaces and ordered Texas Steel to copy it with certain modifications. The Esco point involved in suit has a flat surface at the socket tip, which is the subject of another patent. Texas Steel was instructed to remove this flat surface and to put notches at the tip of the adapter and corresponding bumps in the socket tip of the point. For a period from September 1964 to December 1965 Texas Steel man- . ufactured for Hensley points Nos. 25, 40, 45, 50 and 55 in which the corresponding Esco points 25, 40, 45, 50 and 55 were copied with the changes noted above.

16. Hensley is now manufacturing its 25-size point and adapter and 40-, 45-50-, and 55-size points. All are copies of the Esco points and adapter, with surfaces of revolution on a vertical axis, with changes noted. Hensley points 25, 40, 45, 50, and 55 have been sold as replacements for excavating teeth. In the replacement of points, there is no evidence of a renewal by Hensley of an unpatented element of a patented combination. The renewable element furnished by Hensley, that is, the point, is itself patented.

17. Prior patents do not anticipate excavating teeth with points or adapters having conical surfaces of revolution about a vertical axis.

18. Hensley’s 601 point manufactured by Hensley prior to the patent in suit, does not have either conical upper or lower bearing surfaces of revolution about a vertical axis and does not anticipate the patent in suit.

19.

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Bluebook (online)
251 F. Supp. 631, 148 U.S.P.Q. (BNA) 600, 1966 U.S. Dist. LEXIS 10439, 1966 Trade Cas. (CCH) 71,797, Counsel Stack Legal Research, https://law.counselstack.com/opinion/esco-corp-v-hensley-equipment-co-txnd-1966.