Before MAJOR, KERNER, and MINTON, Circuit Judges.
This is a suit for infringement of United States Patent No. 1,808,091, issued to plaintiff June 2, 1931. The defenses of invalidity and noninfringement were relied upon. The court found the patent invalid, but infringed if valid. Plaintiff appeals from the finding of invalidity and defendants appeal from that of infringement.
The patent is entitled "Pneumatic Tire Tube," concerning which the patentee states:
"My invention relates to a self healing inner tube for use inside of the outer casings of automobiles and trucks, and also to the process of making the same.
"The object of the invention is to provide a tube so designed and processed, that, when same is inflated if punctured, the pressure loss from the puncture is either entirely prevented or reduced to a minimum. * * *
"A feature of my invention is the provision of a tube structure having an inner layer of elastic material which is formed of a predetermined size which inner layer then has applied to the outer circumference thereof a layer of mastic puncture healing material and an outer layer of elastic material, which structure is then cured in a mold of substantially the same size and shape as the inner contour of the casing which receives the tube."
The patentee further states: "the tube of the present invention is formed the same or nearly the same size and shape as it will assume when inflated in the casing and on the rim. In other words, so shaped and sized that it suffers little or no distortion when in use and inflated and so made that the part of the tube which, in use, underlies the tread portion of the casing is much thickened, allowing for an annular cavity throughout the thickened portion of the tube, which cavity is filled with a self sealing plastic compound that tightly adheres to a nail or other puncturing object when it is forced through the walls of the inner tube and the plastic material in the cavity so that the loss of pressure resulting from the puncture is entirely prevented in almost every case and in the few exceptions pressure loss is so reduced that it is negligible."
As to the process employed, the patentee states: "Rubber stock was milled and compounded similar to that in general use in the rubber industry today. From this stock an inner tube is formed, the valve inserted, and the whole formed into an endless rubber ring capable of some distention by having compressed air forced through the valve. The tube in this condition resembles the ordinary inner tube in general use partially inflated except that the tube need not be vulcanized."
The patentee stresses that in his previous efforts, as well as those of others, it was attempted to build the tube on a mandrel or core, after which the ends were spliced. The results thus obtained, so it is stated, were unsatisfactory due to the difficulty of making the splice, which also resulted in wrinkles and distortions in the inner layer of the tube, thereby reducing its length of service. This objection, so it is claimed, was overcome by the process suggested, and it is emphasized that the employment of an air core or an inflated inner member which forms the basis for the finished product is an important feature of the invention.
Claim 2, a process claim, and claims 3 and 6, product claims, are in suit. We think it is necessary to set forth claim 2 only inasmuch as it claims the process used in making the product claimed in claims 3 and 6. Claim 2 is as follows: "The method of making an inner tube for pneumatic tires which consists in forming an endless tube of vulcanizable rubber whose dimensions are slightly smaller than the cavity in the tire casing in which said tube is intended to be used, expanding said tube by internal pressure, applying to the outer circumference of said tube while inflated a layer of plastic sealing compound, covering the said compound with a layer of vulcanizable rubber which extends beyond the edges of the compound and contacts with the endless tube for adhesion thereto and curing the entire tube structure in a mold whose cavity is substantially equal to the size and shape of the cavity of the tire casing in which said tube is intended to be used."
The method thus described consists of four steps: (1) forming an endless tube of vulcanizable rubber whose dimensions are slightly smaller than the cavity in the tire casing in which said tube is intended to be used; (2) expanding said tube by internal pressure, applying to the outer circumference of said tube while inflated a layer of plastic sealing compound; (3) covering the said compound with a layer of vulcanizable rubber which extends beyond the edges of the compound and contacts with the endless tube for adhesion thereto; and (4) curing the entire tube structure in a mold whose cavity is substantially equal in size and shape to the cavity of the tire casing in which said tube is intended to be used.
As we understand, step (2) is relied upon as distinguishing the process from that disclosed by the prior art and which, it is claimed, gives to the process a patentable status. It must be assumed, so we think, that steps 1, 3 and 4 were old in the art; in fact, we do not understand plaintiff to make a contrary contention. The essential point with reference to step (2) is that it teaches the application of the plastic sealing compound to the outer circumference of a tube while inflated, in contrast to what had theretofore been disclosed, that is, its application to a tube in its deflated form. Plaintiff's contention in this respect is stated in its brief as follows: "This placing of the plastic material on the base tube when the base tube has the size and form it will have in ultimate use, so that the plastic then takes exactly the same position it will have in ultimate use, is new with Waber. No one but Waber has put on the plastic sealing layer in this way."
A large number of prior art patents were offered in evidence, the most pertinent no doubt being Wallace No. 1,258,506, issued in 1918, Crombie No. 1,498,017, issued in 1924, and Wildman No. 1,601,013 issued in 1926. It is hardly open to dispute but that all the steps shown in Waber's process claim in suit and all the ...