The prior art is surprisingly barren of machines directed to filling containers with semiplastic material. The general idea of using telescoping tubes is old and appears as early as Strong, No. 34,379. This patent, however, is not remotely related to the process which is the function of the Vogt and Wymond patent. It is directed to filling bins with grain and the tubes are kept elevated above the rising pile of material, which is showered down. Any pressure from a plate attached to the conduit would defeat the purpose of the patent. Webjorenson, No. 653,750, has to do with filling cans with semi-fluid substances, although it does not mention ice cream. It discloses pressure from a plate upon the rising surface of the material in the can and yielding means opposed to the pressure, but it has no telescoping tubes. The only element of the patent in suit which it shows is the variable opposition to the filling pressure by a spring.
All of the elements of the '106 patent can be found separately in the prior art, but I think that it involved invention to combine them in the manner in which it has been done, and that they are functionally related in a new way.
The accused structure is almost exactly like that of the patent, with the single exception that, instead of a spring, the yielding means to lift the telescoping conduit with its pressure plate is a counterweight suspended on a cable and pulley. I agree with the defendant's contention that since the force of the counterweight is constant and since it acts against a variable (the drag force exertedby the material flowing through the tube) it will not maintain the pressure plate in contact with the upper surface of the ice cream with a substantially constant pressure. Since claim 5 is a functional element ("yielding means") other yielding means which wholly fail to perform form the described function can not be held to be equivalents.
Claim 4 is broader. All that is required of the means in the third element of this claim is that it lifts the pressure plate and will "counteract the effect of the said drag." The defendant's argument for non-infringement requires that the word "counteract" in this element must be read as meaning opposition which equalizes the variable force of the drag at all times. Hence it must mean variable opposition. Hence it applies to a spring and can not apply to a counterweight.
This reading would make the claim the practical equivalent of claim 5 -- a construction usually to be avoided. Symington Co. v. National Castings Co., 250 U.S. 383, 39 S. Ct. 542, 63 L. Ed. 1045; Smith v. Snow, 294 U.S. 1, 55 S. Ct. 279, 79 L. Ed. 721. I am not able to find the necessity for such a limitation, either to save the patent from the prior art or in the specification or to preserve its essential function. It has not been shown why an absolutely, or even substantially, constant pressure is necessary to accomplish the filling of the cans in the desired manner. All that is necessary is a pressure which is sufficient to eliminate voids. Of course, it must not become so severe as to actually compress the volume of the ice cream and reduce the overrun, but there appears to be no danger of that in the patented structure, and the defendant has not suggested that his device, in which the pressure is not constant, does not operate satisfactorily within these limits.
My conclusions are:
1. Claims 3 and 5 of Patent No. 1,783,864 to Vogt are invalid, being anticipated by Patent No. 1,113,807 to Meisenhelter and the machines made in accordance with it.
2. Claims 3 and 5, if valid, would be infringed by the defendant's process.
3. Claims 18 and 19 of Patent No. 1,783,867 to Vogt are invalid for want of invention over the prior art.
4. Claims 18 and 19, if valid, would not be infringed by the accused freezer.
5. Claims 3 and 4 of Patent No. 1,972,253 to Vogt are invalid for want of invention over the prior art.
6. Claims 3 and 4, if valid, would not be infringed by the accused freezer.
7. Claim 4 of Patent No. 1,881,106 to Vogt and Wymond is valid and infringed by the accused can filler.
8. Claim 5 of Patent No. 1,881,106 to Vogt and Wymond is valid, but not infringed by the accused can filler.
In addition to the foregoing conclusions the statements of fact contained in this opinion may be taken as special findings of fact in compliance with Equity Rule 70 1/2, 28 U.S.C.A. following section 723, and the statements of law as conclusions of law in compliance with the same rule.
A decree may be presented in accordance with the foregoing.