337 F.2d 833 (6th Cir. 1964), 15439, Tillotson Mfg. Co. v. Textron, Inc., Homelite

Docket Nº:15439, 15440.
Citation:337 F.2d 833, 143 U.S.P.Q. 268
Party Name:The TILLOTSON MANUFACTURING COMPANY, Plaintiff-Appellant, v. TEXTRON, INC., HOMELITE, a Division of Textron, Inc., Defendant-Appellee. The TILLOTSON MANUFACTURING COMPANY, Plaintiff-Appellee, v. TEXTRON, INC., HOMELITE, a Division of Textron, Inc., Defendant-Appellant.
Case Date:November 06, 1964
Court:United States Courts of Appeals, Court of Appeals for the Sixth Circuit

Page 833

337 F.2d 833 (6th Cir. 1964)

143 U.S.P.Q. 268



TEXTRON, INC., HOMELITE, a Division of Textron, Inc., Defendant-Appellee.



TEXTRON, INC., HOMELITE, a Division of Textron, Inc., Defendant-Appellant.

Nos. 15439, 15440.

United States Court of Appeals, Sixth Circuit.

November 6, 1964

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W. Brown Morton, Jr., New York City, Carl F. Schaffer, Owen & Owen, Toledo, Ohio, on brief; Robert McKay, Charles J. Brown, Pennie, Edmonds, Morton, Taylor & Adams, New York City, of counsel, for Textron.

Before WEICK, Chief Judge, and O'SULLIVAN and PHILLIPS, Circuit judges.

WEICK, Chief Judge.

These appeals arise out of patent infringement actions between the same parties, involving two patents for improvements of diaphragm type carburetors of different design and construction. They were argued together.

The District Court referred both actions to a Special Master who heard the evidence, considered them separately, wrote opinions and made findings of fact and conclusions of law in each case. These findings of fact and conclusions of law were approved and confirmed by the District Court.

In Appeal No. 15,439, the District Court held that Claims 1 and 2 of Phillips Patent No. 2,733,902 were invalid and not infringed by the accused carburetors of defendant. Plaintiff appealed only from the judgment declaring the patent invalid.

In Appeal No. 15,440, the District Court held that Claims 4 to 7, 9 to 12 and 14 to 17 of Phillips Patent No. 2,841,372 were valid and infringed. Defendant appealed.

Phillips, the inventor of both patented carburetors, assigned the patents to the plaintiff.

APPEAL No. 15,439


Diaphragm carburetors were developed to permit the operation of small two-cycle combustion engines at extreme angles from vertical or inverted positions without leakage of the fuel. This could not be accomplished with the float type carburetor. The development extended over a period of many years. Phillips was not the first to design such a carburetor although he unquestionably contributed significant engineering advances in the field. The carburetors were used primarily for the operation of chain saws although they could be used to power lawn mowers and boats.

Carburetors of the general type disclosed in Claims 1 and 2 of the patent

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were not new. 1 These claims define an improvement, namely, the combination of valve means (shown in the specification as a mechanical check valve) in the main fuel orifice of the carburetor to prevent or interrupt, when the engine is idling, the back flow of air from the mixing passage of the carburetor through the main fuel orifice into the idling chamber. This flow of air is called back-bleeding.

The problem of back-bleeding or reverse flowing of air does not arise when the engine is operating at high speed with the throttle valve open. It occurs when the throttle valve is closed and the engine is idling and supplied with fuel through an idling orifice which is separated from and located some distance away from the main fuel orifice. The air pressure at the main fuel orifice is greater than at the idling orifice and the air flows back from the mixing passage through the main fuel orifice into passage ways leading to the idling orifice. This mixes too much air with the idling fuel making the mixture so lean that the engine will stall. To stop or interrupt this reverse flow of air Phillips provides valve means. The patent drawing (Fig. 4) discloses a ball check valve located in the main fuel orifice.

When the engine is operating with the throttle open, fuel is sucked from the fuel chamber through the main fuel nozzle. This suction lifts the ball valve off its seat and permits the free flow of fuel through the main fuel nozzle into the mixing passage. When the throttle is closed and the engine is idling, there is a suction in the reverse direction through the main fuel nozzle into the fuel chamber. The ball check valve is sucked onto its seat thus preventing the back flow of air into the fuel chamber.

Phillips' application for patent had 'rough going' in the Patent Office. In the first action, the Examiner cited the following references against it:

Wirth et al 2,345,168 (1944)

Wirth 2,445,097 (1948)

Brunner 2,568,987 (1951)

Sloane 2,569,782 (1951)

Carlson et al 2,339,320 (1944)

The Examiner rejected all the claims of the patent as unpatentable over Wirth et al 'which shows the diaphragm actuated fuel inlet valve for the chamber 11, the air chamber 75, and the main and idling fuel systems.' The Examiner was of the view that the arrangement of Wirth for controlling the inlet valve is the full equivalent of Phillips' arrangement and it 'teaches the use of a check valve in the idling system to prevent back flow therethrough.' He noted that Brunner and Sloane also teach the same.

Phillips filed an amendment. The Examiner again rejected all of his claims

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as unpatentable combinations citing as additional references:

Rubatto (Italy) 311,708 (1933)

Gistucci et al 2,156,115 (1939)

Clesse (France) 985,460 (1951)

The Examiner thought that Gistucci showed a fuel regulator structure similar to Phillips' while Rubatto showed the main and idling fuel system together with a throttle check valve for closing the main discharge nozzle while the idling parts are discharging. Gistucci et al provided a spring that opened the fuel inlet valve that is biased to closed position by another spring. The Examiner stated it would not be invention to add the fuel systems of Rubatto to the regulator of Gistucci et al. He was of the opinion that the lever and the diaphragm arrangement of Gistucci et al was the full equivalent of Phillips. In view of the teachings of Wirth et al, the combination of Rubatto and Gistucci et al was considered obvious to one skilled in the art.

Clesse taught the use of a spring acting on a lever and diaphragm for controlling a fuel inlet valve biased to open position in a carburetor.

Phillips filed a second amendment and the Examiner for the third time rejected all of the claims.

A third amendment was filed which finally resulted in an allowance of six claims.

The Special Master considered references which were not cited by the Examiner, namely, Bracke 2,680,605 and the McCulloch 3-25 chain saw.


The application for the Bracke patent was filed on October 20, 1950 and it is undisputed that the patent is a valid reference. The Bracke application for patent was pending in the Patent Office at the same time of Phillips' application which resulted in '902. No interference proceeding was instituted. The Patent Examiner apparently did not know of the Bracke patent as he most certainly would have cited it as a reference.

Bracke is similar in many respects to Phillips '902 as defined in Claims 1 and 2. Bracke asserts that his carburetor operates in all positions and that one of its objects was to provide new and improved means for preventing back-bleeding. The Special Master found that Bracke has the same general arrangement of parts as specified in these claims and employs a mechanical check valve to prevent back-bleeding which is a full equivalent of the check valve used by Phillips in his main fuel orifice. He compared the disclosure in Bracke with Claim 1 of Phillips and with one exception found that they both provided for substantially the same elements. The exception was that in Phillips the fuel inlet valve operates to close the supply duct against pressure of the fuel while in Bracke the fuel valve operates in the direction of fuel to close the duct. He stated that both types of valves were old, well known in the prior art and are considered as equivalents. Mr. Phillips, in his testimony, admitted that the use of a needle valve with the point of the needle opposed to the delivery of fuel is conventional. Valves moving against pressure to close an inlet were shown in Armstrong Patent 2,724,584, Conover 2,713,854, Ensign 2,653,228 and Phillips earlier Patent 2,387,676. Claim 2 of '902 provided for a lever pivotally supported in the chamber and in constant engagement with the diaphragm. The use of levers of different types to transmit force is old. A pivoted lever was shown in Armstrong, Ensign above-mentioned and Ensign Reissue 22,151. None of these references were cited by the Patent Office.

Bracke used a spring biased stem connected with the valve which provided the force of a lever although it was not pivoted. Nor do we think that patentable invention was shown by Phillips locating his inlet valve duct at the side of the structure instead of in the center of the diaphragm as provided by Bracke.

The Special Master was of the view that Bracke anticipated Phillips. In our judgment, Phillips was obvious in view

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of Bracke to a person skilled in the art. There is no invention.

Tillotson claims that the Special Master and District Court erred in holding that the check valve to prevent back-bleeding was the crux of Phillips' invention. We find no error in this conclusion. In our judgment, the device to prevent back-bleeding was the principal part of the invention without which it would never have been successful.

Tillotson claims that Bracke was a paper patent and that carburetors embodying its features were never manufactured and sold. This contention is irrelevant on the question whether its disclosures constituted anticipation. Coats Loaders & Stackers, Inc. v. Henderson, 233 F.2d 915 (CA6, 1956). Such a patent does not indicate lack of invention. Edward Valves, Inc. v. Cameron Iron Works, Inc., 286 F.2d 933 (CA5, 1961). Failure to use a patent does not affect its validity. Special Equipment Co. v. Coe, 324 U.S. 370, 65 S.Ct. 741, 89 L.Ed. 1006 (1945).


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