Thomson Spot Welder Co. v. Ford Motor Co.

• Decision Date: 28 June 1922
• Docket Number: 3555.
• Citation: 281 F. 680
• Parties: THOMSON SPOT WELDER CO. v. FORD MOTOR CO.
• Court: U.S. Court of Appeals — Sixth Circuit

281 F. 680

THOMSON SPOT WELDER CO. v. FORD MOTOR CO.

No. 3555.

United States Court of Appeals, Sixth Circuit.

June 28, 1922

Frederick P. Fish, of Boston, Mass. (J. L. Stackpole and H. F. Lyman both of Boston, Mass., on the brief), for appellant.

Melville Church, of Washington, D.C. (Barthel, Flanders & Barthel, of Detroit, Mich., A. S. Pattison, of Washington, D.C., and O F. Barthel, of Detroit, Mich., on the brief), for appellee.

Before KNAPPEN, DENISON, and DONAHUE, Circuit Judges.

KNAPPEN Circuit Judge.

Suit for infringement of United States patent No. 1,046,066 December 3, 1912, to Johann Harmatta, assignor to Thomson Electric Welding Company, which is the predecessor of plaintiff company. The invention relates to that branch of electric resistance welding known as spot welding, by which two sheets of metal are welded together in spots, as a substitute for riveting. Generally speaking, the welding is accomplished by the application of pressure and heating current, localized in spots on the opposite plane facts of the two metal sheets. Specifically, two pointed electrodes are applied to the opposite faces of the sheets, the electrode which feeds the electricity into the work and heats the metal to the welding point being caused to exert the pressure required to accomplish the weld. The specification states that--

'The necessary pressure may be exerted at the place of welding by the aid of any of those technical means which are suitable for producing or transmitting pressure-- e.g., with a press either direct or by means of indirect transmission by levers or it may be by means of simple hand levers, that is to say, by means of direct or indirect manual power, or by other means.'

The 21 claims of the patent relate some to the process, the others to the product. Plaintiff relies on claims 3, 8, 12, and 17 as typical. They are printed in the margin. ^[1] The prominent defenses are anticipation, lack of invention, prior public use, and estoppel. The District Court found each of these defenses established and dismissed the bill. 268 F. 836. Noninfringement is pleaded but not urged

The patent has been adjudicated in but one other suit, viz., Thomson Electric Welding Co. (plaintiff's predecessor) v. Barney & Berry, in the First Circuit, decided in 1915. In that case Circuit Judge Dodge, who presided in the District Court, held the patent void for lack of invention. The Circuit Court of Appeals held that the patent was not anticipated and that it involved invention, and reversed the judgment of the District Court. The opinions of both the District Court and of the Circuit Court of Appeals are reported in 227 F. 428 et seq., 142 C.C.A. 124.

The art of electric resistance welding was old and far advanced in 1903, when the Harmatta patent was applied for. Prof. Elihu Thomson, the head of plaintiff company and of its predecessor, was a pioneer in that art. In 1886 he obtained process and apparatus patents respectively (Nos. 347,140 and 347,141) for so-called butt welding, which involved the uniting of the abutting ends of metal wires, bars, etc., by applying heat at the joint and the adjacent surfaces by means of electrodes, and pressing the two pieces together when heated to welding temperature. There was here true resistance welding, with pressure of the parts involved, although the electrode did not exert the welding pressure. In 1889 Thomson obtained a patent (No. 396,015) for electric riveting, which involved the heating of the rivet when in place by means of a current passed through it by the use of electrodes, under pressure thereon, the effect being not only to swage the rivet and weld it to the adjoining metal, but apparently (when desired) to weld together, in part at least, the portions of the plates immediately adjoining the rivet.

In 1891 Thomson obtained a patent (No. 444,928) for what is called lap-welding. While the specification states that the invention is specially adapted to the welding of the overlapped edges of plates, it is not so limited, but expressly includes 'welding together strips, sheets, plates, or bars of metal where it is desirable to form a joint of considerable length. ' According to the specification, 'the surfaces to be welded are pressed together to form a union,' the work being fed in the longitudinal direction of the joint 'through suitable pressure devices (preferably roller electrodes), the work being properly arranged, so that the pressure devices will press the surfaces to be welded together and simultaneously passing the electric current through the work at the point of pressure. ' The electrodes were employed to exert the welding pressure. The specification further states that 'as the work is passed through such rolls with a continuous motion each point, as it comes between the rolls, is heated and the surfaces pressed together,' etc. By way of further description of one of the figures it is said that--

'The electric current being now turned on as it passes from one roller to the other and across the point of pressure will heat the work to the welding temperature * * * after which the screw can be given a few more turns to effect a solid union. The work having been thus started, may now be moved along through or between the rolls so as to bring successive parts of the joint into position to be pressed and heated at the same time. ' ^[2]

In 1893 Thomson obtained a patent (No. 496,019) relating particularly to soldering sheet metal pieces flatwise, either by the use of solder or (when applied to tin plates) by melting the tin sufficiently to establish union thereby. The electrodes, in the form of clamps or otherwise, served not only to supply the necessary heat, but to exert sufficient pressure upon the overlapped sheets to effect their union. A roller electrode is disclosed, performing the double function of heating and pressing, and having its periphery corrugated or grooved. As stated in the specification:

'The rollers exert pressure while the current heats the thin metal pieces at successive points between the rollers.'

This was, to say the least, electric resistance spot soldering.

In 1897 Robinson received a patent (No. 574,942) on so-called projection welding, as specially applied to the welding of a splice bar to the web of a railroad rail, the splice bar having upon its inner face a number of projections which by the application of the heating current are fused, and by pressure made to form welds between the projections on the bar and the fused opposing portions of the rail. Kleinschmidt, in 1898, took out a patent (No. 616,436) for a similar process, and by methods not essentially unlike those of Robinson.

Whether or not the Thomson so-called lap-welding invention should be regarded as an absolute anticipation of the Harmatta patent we think the state of the art to which we have referred left no room for invention in Harmatta. Thomson's lap-welding patent is criticized as not plane-face welding, much less spot-welding. We see no distinction upon principle between plane-face welding and lap-welding; the former certainly embraces the latter. If Thomson's roller electrode device was capable of welding a line or seam in a metal lap joint, it was readily adaptable to line-welding together coterminous plane-face plates. Harmatta's original application (made in ignorance of Thomson) disclosed roller electrodes broadly enough to include that very use. We think Thomson's lap-welding invention was in essence a welding in...