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Cornell v. Chase Brass & Copper Co.

April 20, 1944


Appeal from the District Court of the United States for the Southern District of New York.

Author: Chase

Before SWAN, CHASE, and CLARK, Circuit Judges.

CHASE, Circuit Judge.

This appeal is from a decree of the District Court in a suit for the infringement of United States Patent No. 2,025,973, which was granted on December 31, 1935, to the American Radiator Company as assignee of the application of this plaintiff, as the inventor, filed June 6, 1934. The plaintiff has become the owner of the patent and no question is raised as to his being the proper party to sue thereon.

The patent was granted for a "Hollow Wrought Metal Body and Method of Making Same". Though its scope is by no means limited to commercially pure copper pipe fittings in the form of a T, it is convenient and adequate for present purposes to discuss it primarily in that aspect as the parties have done. The plaintiff relied on article claims 1 to 6 inclusive and on method claim 8. They were all held invalid and, if valid, not infringed.

The suit is the ordinary one for infringement and an accounting and for a preliminary and permanent injunction. The defendant added to its answer denying infringement a counterclaim under the Declaratory Judgment Act, 28 U.S.C.A. ยง 400, alleging that the patent was invalid and praying for a decree to that effect.To the issues of validity and infringement there is now added the denial of the plaintiff's motion to reopen the cause after trial to permit the introduction of additional evidence claimed to have been newly discovered.

The patent teaches that the hollow wrought metal body with which it is concerned is to be pressed out of a cold tubular blank of the metal. It is put in a die having the required interior size and conformation to shape the exterior and having a changeable mandrel and changeable punches, so positioned and shaped that the interior will be properly formed at the same time by the flow of the metal under pressure. The operation is completed by drilling and reaming out webs of metal left by the die forming process. Pressures of an order as high as from 100,000 pounds to 500,000 pounds per square inch are used, depending upon the size of the article made.

The die used to make a T, for example, is in the conventional split construction with suitable means for holding the halves in proper alignment in the well-known die press. Though the specifications are not limited to "a lateral pipe fitting of integral wrought metal predominantly of copper content," the claims in suit are so limited. Such copper pipe fittings are desirable for use with copper pipes or tubing where sweat joints are to be made, for their expansion under the application of heat in the making of the sweat joint is like that of the same material in the pipe and thus the proper clearance is maintained for the inrun of the solder under the influence of capillary attraction. As the amount of clearance in making a sweat joint is critical within comparatively small limits, it is essential that the fittings be hard enough to be stored in bins and handled in the ordinary way by pipe fitters without being so distorted that the proper amount of clearance will be disturbed.

The patentee secured this desirable hardness in his wrought copper T by a cold working of the metal to make it approach its maximum in that respect. As is well known, cold working so changes the grain of copper that the metal is hardened, and in making the patented T no heating whatever is used to lessen the hardness so imparted. On the contrary, at the start of each successive stage in the process the metal is as hard as it was at the end of the previous stage.

By "stages" in this connection we mean the several applications of pressure to the metal in the die. The first takes place after the straight tubular blank has been inserted; the first mandrel or plug is in place in that part of the die in which the lateral branch is to be formed; and the first punches are in position with their conical inner ends within ends of the blank. The blank, of course, has been given the required length and side thickness to provide the metal content needed for the particular object to be made. Then quick pressure of the requisite amount drives the punches part way into the ends of the blank. As the diameter of the punches is smaller than the outside diameter of the blank by the amount of thickness which the walls of the finished fitting are to have, that amount of metal is left between the punches and the sides of the die as the punches advance toward each other. The excess metal in the blank is moved to form a solid mass between the conical ends of the punches, and some of it is pushed out around the end of the mandrel, which is tapered, and into the space between the mandrel and the sides of the die enclosing it. Thus there is the beginning of the formation of the lateral branch.

The next stage follows the removal of the first punches and of the mandrel and the insertion of others. The second mandrel has a rounded end and the second punches have cylindrical ends of reduced diameter. Again quick and high pressure is applied to the punches to drive them forward until they come so close to meeting that only a thin film of the metal is left between their forward ends. The metal flow thus induced forms more of the lateral branch.

The next stage is preceded by a removal of the mandrel only. In its place is inserted a punch having a rounded end and a diameter less than that of the mandrel removed. Pressure on that punch drives it toward the inner ends of the other two punches, which have been left in place, until there is but a thin partition of metal between the inner ends of the three punches. The displaced metal flows into the remaining space between the new punch and the sides of the die enclosing it to fill that space and complete the formation of the lateral branch. Then all the punches are withdrawn and the film first mentioned is drilled out. When that has been done, the second film of metal is removed with a combined drill and reamer which forms a stop or shoulder as an abutment for the pipe end when the fitting is used, similar shoulders having been formed near the other ends of the fitting by the last punches there used.

What is now claimed to be new in this process is the use of the patentee's blank. As the appellant candidly admits in his brief, "his invention resides in the use of a tubular copper blank." That the prior art leaves no wider scope to be given to what he did from the standpoint of invention is made clear by the evidence in this record which shows, as was found by the trial court, that it was old to make articles of various shapes by the cold working of copper and other metals by means of dies and punches under pressure, and that many of these articles were hollow. It was likewise well known that metals commonly used to make pipe fittings could be similarly worked when heated and that the softening effect of heating would make the metal flow in the die more easily, i.e., upon the application of less pressure. Moreover, the effect of heat upon the grain structure of such metals was known, and where it was considered more important to obtain qualities imparted to the metal by cold working than to provide ease of metal flow by heat softening with its resultant effect upon the metal itself, the choice of methods was made accordingly. The general practice has long been that the softer metals are usually worked cold and the harder ones are worked heated.

Consequently, prior patents which disclose die pressure methods of making pipe fittings and the like out of metals long used in the manufacture of such articles are pertinent prior art though they advocate the use of heated blanks. United States Patent No. 689,204, granted to Larkin on December 17, 1901, is one of them. It shows metal movement in mass under pressure inside a die, applied to a blank of metal heated to a plastic state. Another example is No. 1,445,140, granted to Kellogg on February 13, ...

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