The opinion of the District Court states the facts with sufficient detail and to it we refer. In respect of No. 1,443,795, the critical question relates to the phrase, “a control •device external to the conduit connection,” which occurs in both claims. It is quite true that this reads literally upon the defendant’s machine, but the two apparatuses are so totally unlike each other that to cover the defendant’s machine the words must be understood so generally as to make the invention depend merely upon the idea'of putting the stopping means outside the tube. Not only is the defendant’s result arrived at by totally different means, but it is a different result, because Maelaren controlled his air by stopping his motor and wholly shutting off the current, while the defendant partially chokes the tube and lets the exhaust fan run on. This, as a method to economize power, was anticipated by Stoetzel. The defendant descends from that invention; Maelaren adopts an entirely different plan. Again, in means, the defendant went to Libby, and has been enjoined from doing so, and from Libby Maelaren took nothing.
It is, as we have often said, quite impossible to lay down any objective rules, and we should be unwilling to say unconditionally that it could under no conceivable circumstances have been an invention to put outside the tube the means by which the air flow is stopped or diminished. One may imagine that an art that showed a protracted groping for such a change and an immediate response to its discovery. That was not the case. There is not a tittle of evidence to show that this, or, for that matter, any other, feature of Maclaren’s machine was • ever welcome anywhere. Nor is there any reason to suppose that the location of the stopping means was other than the inevitable consequence of electrically controlling the flow of air by a “start and stop” system. We quite agree with the learned District Judge in saying that there was no invention in that.
If pressed dialectically by the words used, we should say that “means for stopping the carrier-propelling flow of air” may only mean that the flow of air was altogether stopped as Maelaren stopped it, and not merely reduced so low that it would no longer carry parcels. Literally, of course, the flow of air ceases to be “carrier-propelling” when it will not propel carriers; but the Examiner who allowed the claim, and who had before him Maelaren’s machine, was almost certainly not conscious of the pregnant ambiguity which is now used to cover devices wholly different in purpose and design. We see no reason to declare claims 5 and 6 of No. 1,443,795 invalid, but they certainly are not infringed.
The infringement of claim 10 of No. 1,396,449 turns on the phrase, “operating means to control the pressure on s.aid device to operate same and thereby move the valve.” If the defendant’s abandoned device (Fig. 2), the only one which can on any view infringe, is to be caught within this language, it must be because the element just described and that which follows coalesce, and are embodied in the parts 12 to 16 of the defendant’s figure 2. Of course, it makes no difference that an infringer consolidates two features of the claim into a single part of his apparatus, and the question is whether both are in fact represented. The difficulty we find is that the “means to control the pressure” on the valve 121, so as to move it, is not the same kind of means as that which the defendant uses to move the valve, 21, which is its analogue. Maelaren had to start his air current by manual operation, because his whole system was normally inert. If a package was inserted, nothing automatically happened. It was only by opening the chamber, 125, to the atmosphere that he could establish a different pressure on the two sides of the diaphragm, 121, and this had to be done manually. This would have been as much the case, if-it had been the valve, 157, which was manually operated, as it was with matters as they stood.
Had the valve, 117, been seated so as not wholly to close the pipe, we do not see how the defendant could escape infringement, but that would have eliminated all need for .the valve, 135. The necessary changes are trifling enough, once one has determined to make that kind of machine; but that determination revolutionizes the whole plan of its operation, and incidentally makes useless the elaborate means of starting and stopping the motor. As the disclosure stands the claim does and must include the valve, 135, as a necessary element, since the apparatus would not work without it, and there can he no infringement unless the defendant uses some counterpart, which it does not. There is therefore no room for invoking the doctrine of equivalents.
Decree modified, by dismissing the bill for *24lack of infringement in respect of each patent.
ROGERS, Circuit Judge, through illness, was unable to take part in the decision of this ease.