Piston Ring Co. v. Burd High Compression Ring Co.

276 F. 357 | 7th Cir. | 1921

ALSCHULER, Circuit Judge.

The bill alleged infringement. by appellee of United States patents, No. 1,050,102, January 14, 1913, to Campbell, and reissue No. 14,644, May 6, 1919, to Ranchester, both for manufacture of' cast-metal piston ring packings for steam and internal combustion engine cylinders. Among the defenses interposed were noninfriugement and invalidity of patents. The Campbell patent is for a process of making piston rings or patterns for piston rings by radially splitting the round pattern, spreading apart the severed ends, and inserting a segment in the space, whereby the expanded ring becomes more or less distorted from the true round, and using such expanded and distorted ring as a pattern for casting the rings, which when cast have cut from them a piece corresponding with the inserted segment in the pattern. The casting is then compressed, bringing the ends in contact, and while so held is.ground or cut smooth on its outer surface.

Upon being compressed so that the ends practically contact, the ring presumably takes the substantially round form of the original ring of the pattern before it was cut and spread. The ring is sprung into the grooves cut in the piston to receive it, and is then compressed for insertion into the cylinder. The tendency of the ring when within the cylinder being to resume its normal expanded form, it presses against the smooth inner wall of the cylinder, producing, to the extent of the perfect roundness of both cylinder wall and the compressed ring, a substantially tight fit between the two, and thus prevents loss of power through leakage of steam, gas, or oil between cylinder wall and ring.

The fit of the opposite side of the ring against the inner surface of the piston groove need not and cannot be so exact, and this side of the ring may be left without cutting or grinding, which conduces to the desired greater resiliency of the cast ring, as well as to simplicity and cheapness of fabrication.

The Tanchester patent devices sued on are one of its two process claims, and its two product claims, which seem to be for a ring produced through and by means of the process set out in the other claims. But in effect the two patents are so similar as quite irresistibly to invite the conclusion that their coverage is substantially identical.

It is apparent that the nearer true round the compressed metal ring is as it presses against the round inner wall of the cylinder, the better will be the contact- and inore perfect the fit. Cast iron, which both employ, has long been found to be a desirable metal for such rings. The uncontradicted evidence is that appellee makes its pattern rings by first producing a soft brass round drum of a circumference substantially equal to that of the cylinder wall, making proper allowance for shrinkage and finishing, plus a compression space to be left between the ends of the ring when finished and in normal expansion. This brass drum is bored so that the shell remaining is of the thickness of the rings to be made from it. Prom this hollow drum there are then cut rings of the width of the finished piston ring, and the round brass ring is then distorted by the skillful operative into somewhat elliptical shape. From this a casting is made, and from the casting there is excised a piece, so that what remains will be substantially the length of the inner circumference of the cylinder. The compressed casting, is ground on its outer surface, and a round template of desired size applied to find where it is out of round, and the ring bent accordingly, and further test castings made, until one is cast which on finishing as aforesaid will be sufficiently round for practical purposes, and this is thereupon .the pattern for casting the commercial rings.

Leaving the inner surface of the ring unground or uncut (which appellee also does), arid thus contributing to the resiliency of the ring, is no part of the claimed norelty. This is but an incident in the manufacture of such rings. There is manifestly no need for close contact between the inner surface of the ring and the, adjacent surface of the groove in the piston. There is no frictional contact which would require smoothness of this surface of the ring or the adjacent surface of the groove, and, indeed, the very purpose in having the ring springlike and expansible forbids its close fit with the inner surface of the groove; for in the original expansion, and surely in its further expansion to take up space caused by wear in cylinder wall, there is necessarily some space between inner surface of the ring and the inner surface of the groove. This quality of increased resilience through leaving the inner surface as it was cast, though much lauded in briefs and arguments of counsel, and mentioned in the descriptive part of the Campbell patent, is not referred to in the claims of either.

Expansible metal piston rings are very old in the steam and gas engine art. They were produced and employed in vast numbers long before the patents in suit, and in great variety have been produced and sold ever since. The art has been long so crowded as scarcely to admit of any advance which is basically broad.

Appellant’s large commercial success is urgently pressed in furtherance of the claim for broad interpretation of the patents, as well as in support of their validity.' From the record it appears that since their start of about twelve years ago, appellant’s business in metal piston rings has grown to be larger than that of any one of its ninety or more competitors in this country, who make metal piston rings. While in cases of doubt commercial success of a patented article may tend strongly to influence conclusions favorable to the patent, we know too well of those many notable instances where rapid and signal commercial success has been achieved through improved business methods, appearance, uniformity, and dependability of product, favorable business connections, or a variety of other causes, all wholly apart from monopolistic grants or advantages, to admit of any general rule that because of the coincidental fact of holding a monoply, this alone must account for the achievement.

Conceding the claims to the extent of their purport, we are convinced that appellee did not employ the process of the patents, and that its product is not the result of their teachings.

In an opinion by Judge Geiger filed in the District Court about five months prior to the entry therein of the decree, the question of infringement was fully considered, and the conclusion of noninfringement reached. With that conclusion and the cogent reasons therefor, as in such opinion stated, we are in entire accord. This of itself, without regard to the question of validity of the patents, which in the same opinion is exhaustively considered, requires us to affirm the general decree of the District Court dismissing appellant’s bill with costs.

Decree affirmed.