Window Glass Mach. Co. v. Pittsburgh Sheet Glass Co.

18 F.2d 63, 1927 U.S. App. LEXIS 1876
Court of Appeals for the Third Circuit·Decided March 9, 1927·No. No. 3495·Published·Cited by 1 cases

Opinion

BUFFINGTON, Circuit Judge.

This This case concerns certain claims of three glass apparatus patents granted to Lubbers, Nos. 886,618, 914,588, and 1,020,920, all of which claims, with the exception of claim No. 5 of the first, were before this court in litigation herein referred to. Nos. 886,618 and 1,-020,920 relate to the automatic venting of pulsations which have their pulse origin within the cylinder. No. 914,588 concerns the off-center adjustment of the bait and molten glass, body from which glass cylinders are drawn. We premise this opinion by saying that it concerns, and is addressed only to, those familiar with the intricate art of machine making window glass, and, confining ourselves accordingly to the bare statements herein made, it may not be intelligible to others. We are here concerned initially with the Lubbers patents which relate to automatic venting, a phenomena described on pages 374 and 375 of 261 F. hereafter referred to as the consolidated case.

The patent device which was held by this court in the last-mentioned case is not described in the upper court’s opinion, which opinion we may say was confined to the question of the patent’s validity, but it was particularly described by the lower court, and the reasons for its holding the infringement were by such lower court stated as follows: “It is clearly established that at the time of the filing of the bill of complaint the defendants used a special vent hole in .the pipe leading from the fan to the blowpipe on the cage. That the air did escape through this vent hole during the drawing operation in the same way, and for the same purpose, as plaintiff’s vent, is entirely clear. They thereby infringed the claims 20 to 25, both inclusive, of apparatus patent No. 886,618, claims 3, 6, 7, and 8 of its companion method patent No. 1,-020,920. It is defendants’ position that since the bills were filed they have plugged up the [64] vent holes, and successfully operate without them. What the defendants have done since the commencement of the suit is, strictly speaking, not an issue here. But in defendants’ operation the .supply of air to the cylinder is regulated by the speed of the fan. And the testimony clearly establishes that, when they plugged the open vents, they cut down the fan blades, and removed the side rings or plates from the blades. This increased the clearance space between the blades and the •casing in which they rotate, which caused an effective and continuous vent back through the fan itself. At the same speed, the fan so cut down gives less pressure in the supply pipe than before. Had defendants desired merely to reduce the pressure, this could have been done easily and cheaply, as the evidence shows, by simply throttling the air inlet to the fan. They chose rather to cut down the fan blades and remove the rings. Air is thus drawn in through the central part of the eye of the casing, while at the same time air passes out around the outer part of the eye. This outflow increases as the back pressure from the cylinder to the fan is increased by the pulsations in the cylinder, and thus an effective vent for back pressure is secured.”

From this it appears that the defendants in that case, evidently relying on the invalidity of Lubbers’ vent claims, used Lubbers’ identical vent, but, on the bill being filed, plugged the vent, and thereafter cut down the fan blades from the size used in a standard fan, and thereby, as said by the court, “air is thus drawn in through the central part of the eye of the easing, while at the same time air passes out around the outer part of the eye. This outflow increases as the back pressure from the cylinder to the fan is increased by the pulsations in the cylinder, and thus an effective vent or back pressure is secured.” The standard blower with its cut-down, fan automatically venting was accordingly held in that ease, which was one of an open air system, an infringement of Lubbers’ hole vent. The same patent again came before this court in Window v. Pittsburgh, 284 F. 645, hereafter called the Pittsburgh Case, where the alleged infringement is thus described by this court and differentiated from Lubbers’: “The fans used were standard type, bought in the open market and operated like any fan feeding air through a pipe above atmospheric pressure. The fan fed the air to the cylinder according to the condition of air pressure in the cylinder. When the pressure in the cylinder increased, less air was taken in by the fan; when it decreased, the fan supplied more air; the result of the operation being to keep the pressure relatively constant. To this was supplemented the watchfulness and valve manipulation of the blower. The open vent of the patents is something wholly different. It is in the nature of a self-acting safety valve. It does not control the inflow of air except as it controls the outflow. It requires no human assistance. But in the defendants’ operation the fan delivered air according to the varying conditions of the air pressure in the cylinder and thereby regulated the air pressure of the cylinder in a way different from that of the invention of the patents. That the defendants’ apparatus and method were inferior to those of the patents is of no concern.”

In the case now before us the trial judge was of opinion the defendants’ structure, which is alleged to infringe Lubbers’ vent, was of the same type as that in the Pittsburgh Case, saying: “As we view the system of the defendant in this case, in principle it is the same sort of system that the Circuit Court held did not infringe on plaintiff’s vent patent in the case of Window Glass Machine Company v. Pittsburgh Plate Glass Co., supra.” On the other hand, the plaintiff claimed defendants’ structure was substantially identical with the structure in the consolidated case. Without entering into a discussion of minor questions, it suffices to say that this question of fact underlies, and is decisive of the present case. What, then, are the facts as shown by the proofs in the present case ?

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Window Glass Mach. Co. v. Pittsburgh Sheet Glass Co., 18 F.2d 63, 1927 U.S. App. LEXIS 1876 (3d Cir. 1927).

18 F.2d 63 (Window Glass Mach. Co. v. Pittsburgh Sheet Glass Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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