Cameron Iron Works v. Stekoll

• Decision Date: 27 February 1957
• Docket Number: No. 16050.,16050.
• Parties: CAMERON IRON WORKS, Inc., Appellant, v. Robert O. STEKOLL, d/b/a Speed-O-Valve Co., Appellee.
• Court: U.S. Court of Appeals — Fifth Circuit

242 F.2d 17 (1957)

CAMERON IRON WORKS, Inc., Appellant, v. Robert O. STEKOLL, d/b/a Speed-O-Valve Co., Appellee.

No. 16050.

United States Court of Appeals Fifth Circuit.

February 27, 1957.

James B. Simms, Ralph R. Browning, Houston, Tex., Browning, Simms & Hyer, Houston, Tex., of counsel, for appellant.

Earl Babcock, Duncan, Okl., Lawrence P. Gwin, Bay City, Tex., for appellee.

Before BORAH, TUTTLE and CAMERON, Circuit Judges.

BORAH, Circuit Judge.

Cameron Iron Works, Inc., the assignee of the Herbert Allen Letters Patent No. 2,606,740 for Improvement in Valves, brought this suit against Robert O. Stekoll, doing business as Speed-O-Valve Co., seeking injunctive relief and damages for an alleged infringement of Claims 1 and 4 of the Allen patent.¹

The patent in suit relates to an improvement in valves for controlling the flow of abrasive drilling mud under pressures of as much as several thousand pounds per square inch in the course of drilling deep oil and gas wells. More particularly, the invention relates to the form of the sealing means adapted to seal against the closure member of the valve when the latter is closed. The invention has as its principal object the provision of a valve having a fluid pressure actuated sealing means which will not tend to tear off or be blown past the valve closure member while the gate is being opened or closed. In the complaint it was alleged that the defendant has infringed and is now infringing Claims 1 and 4 of the patent by making, using and vending valves embodying the patented invention, and will continue to do so unless enjoined. In its answer the defendant admitted the issuance of the patent, and denied infringement and the validity of the patent and the claims in suit. With the issues thus joined, a trial on the merits was had and at its end the District Court filed findings of fact and conclusions of law and in conformity therewith entered judgment holding that the Allen Patent was invalid, that there had been no infringement by the defendant, and that the complaint should be dismissed. From this judgment plaintiff appeals.

In view of the fact that the trial court's judgment that the patent was invalid would dispose of the matter, if correct, we direct our attention first to this issue. The Allen patent shows several forms of the invention as embodied in a gate valve structure and a plug type valve structure, respectively, all illustrative of the type of seal constituting the invention covered by the claims. However, and inasmuch as the accused Stekoll valve is a plug valve, we shall confine our discussion to the plug valve shown in the Allen patent. This plug valve embodies the four basic elements which are common to such valves: a conventional housing² having a flow passage therethrough which connects the pipes leading to and from the valve; a chamber in which is located the movable valve closure member; a movable valve closure member, usually called a plug, with a transverse bore which shuts off the flow when turned at right angles to the flow passage; and a sealing element, or gasket, to prevent leakage flow around the plug when it is in closed position. When the valve is in operation and the plug is turned ninety degrees and perpendicular to the flow passage, it interrupts flow through the body and the efficiency of the valve is directly proportionate to the effectiveness of the sealing means under the pressures to which it is subjected.

Claim 1 is an apparatus claim which describes the seal as "a sealing ring of relatively soft yieldable material" surrounding the flow passage and carried by the valve housing on each side of the chamber. The patent drawings indicate that the sealing element consists of two separate rings on the interior of the chamber, one on the inlet or upstream³ side, and one on the outlet or downstream side of the plug. Each sealing ring "having flexible fluid pressure actuated lips * * * said lips having surfaces * * * so that they are adapted when on the downstream side of the closure member to be forced by the upstream pressure into sealing engagement with said closure member," all of which is more specifically set forth in Claim 1.⁴ Although the valve is capable of use with either end as the inlet, the seal is always affected against the valve closure member only around the valve outlet, that is, on the side of the valve away from the greater pressure, and this is due to the fact that the lip seal is so disposed as to permit upstream pressure to pass into the valve chamber but seal it against flowing out of the valve chamber on the downstream side.

Claim 4 describes the sealing means as "a rigid part carried by the body or housing, downstream of the valve closure member * * * said rigid part having an edge conforming with a confronting surface of the valve member when in closed position * * * said rigid part mounted to provide a channel between it and the body or housing, said channel opening into the interior of the body, a resilent lip type seal element within the channel having one lip extending away from said body passage and * * * adapted to be engaged by the valve member when in closed position to seal between the valve closure member and the rigid part." The aforementioned rigid seal ring functions as a support for the flexible seal material, and as closure of the valve is effected, fluid pressure from the upstream side of the valve structure leaks past the sealing ring on the upstream side of the valve and forces the flexible sealing matter on the downstream side into engagement with the valve closure member. The result is that the invention in Claim 4 provides a flexible seal element which engages and seals against the closure member, together with sufficient rigid support and protection to prevent its being blown out by the pressure which enters the valve chamber from the inlet or upstream side.

Even though gaskets with lips which sealed under fluid pressure were well-known in the art prior to the Allen patent, there still existed a problem and that was how to maintain an effective seal which would be actuated by upstream fluid pressure, and at the same time protect the flexible sealing material from damage caused by the valve closure member by reason of the fact that under great pressure such material tended to "bulge" into the housing passage and would be sheared off when the plug turned and latterally slid past the sealing material. Allen's principal objective was to find a solution to this problem and it was with this objective in view that he evolved the novel concept set forth in the patent which was that of arranging the elements of the valve and sealing ring so that as the plug moves from open position towards closed position, no edge of the transverse bore through the plug is required to approach the edge of the sealing material in such a manner as would tend to drag it along with the plug and cut off the edge of the flexible sealing material.

On the issue of validity, the trial court found: that the patent in suit is on a plug valve, that such valves are very well known, and that, any changes in their structure must necessarily be regarded as detailed improvements; that the Allen patent is a mere paper patent, which had never been put into commercial use by the plaintiff; that the patent specifications and drawings disclose a gasket having lips to effect the seal; that the purported invention of the patent resides in the use of this gasket the lips of which act primarily under the influence of fluid pressure; that gaskets of this type were well known prior to the alleged invention of the Allen patent; and that the prior art patent, such as U. S. Letters Patent to Pratt, Nos. 477,605 and 477,607, as well as the specifications and file wrapper history of the Allen patent, limit Claims 1 and 4 to the use of a gasket having lips. On the basis of these findings the court concluded as a matter of law that the Allen patent involved only mechanical skill rather than invention, that it is entitled only to a very narrow and...