Twin Disc, Inc. v. United States

10 Cl. Ct. 713, 231 U.S.P.Q. (BNA) 417, 1986 U.S. Claims LEXIS 808
CourtUnited States Court of Claims
DecidedAugust 27, 1986
DocketNo. 508-78
StatusPublished
Cited by2 cases

This text of 10 Cl. Ct. 713 (Twin Disc, Inc. v. United States) is published on Counsel Stack Legal Research, covering United States Court of Claims primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Twin Disc, Inc. v. United States, 10 Cl. Ct. 713, 231 U.S.P.Q. (BNA) 417, 1986 U.S. Claims LEXIS 808 (cc 1986).

Opinion

OPINION

SETO, Judge.

Plaintiff seeks recovery under 28 U.S.C. § 1498 of reasonable and entire compensation for the unauthorized use and manufacture, by or for the United States, of the inventions described and claimed in U.S. Letters Patent No. 3,328,961 (’961 patent), entitled “Multiple-Stage Hydraulic Jet Propulsion Apparatus For Water Craft”, and U.S. Letters Patent No. 3,405,526 (’526 patent), entitled “Multiple-Stage, Hydraulic Jet Propulsion Apparatus for Water Craft”. The ’961 patent was issued on July 4, 1967, on an application filed October 13, 1965, by patentee George R. Aschauer. The ’526 patent was issued on October 15, 1968, on an application filed March 1, 1967, by patentee inventor-plaintiff George R. Aschauer. Both the '526 patent and the ’961 patent were assigned to Twin Disc Clutch Company, Racine, Wisconsin, a corporation of Wisconsin.

[716]*716A lengthy four-week trial on the merits, including a subsequent two-day oral argument, was held addressing the issues of validity, infringement, double patenting, new matter, statute of limitations, sections 184, 185, and 102(b) violations regarding the 10 claims of the ’961 patent and the 6 claims of the ’526 patent. The accounting phase was deferred for a later trial, pending the determination of liability.

THE ’961 PATENT

The application for the patent in suit was filed on October 13, 1965, by inventor George R. Aschauer, on application Serial No. 495,640, and issued on July 4, 1967. The patent is entitled “Multiple-Stage, Hydraulic Jet Propulsion Apparatus for Water Craft”. The patent application describes a multi-stage hydraulic jet propulsion apparatus for waterborne craft wherein the second stage impeller is driven faster than the first stage impeller and wherein the housing surrounding these impellers converges toward the discharge end. (DX-97, p. 1). The device is shown in the sole drawing present in the ’961 patent, herein reproduced on the following page to facilitate reference.

The multiple-stage, hydraulic jet propulsion apparatus for a water craft consists of a propulsion unit with a housing having an intake 1 flushed with a bottom 2 of the water craft, with a discharge end 3, of the housing, extending through the stern 4 of the craft. (DX-97, p. 3). A Nozzle N extends rearwardly beyond the stern for receiving the stream of water from the housing from the boat, and discharging it to propel, steer, or reverse the direction of the boat. A power plant 5 drives the drive shaft 6, which in turn drives a gear reduction means 7, which in turn drives the drive sleeve 8 within the housing H.

A first stage impeller 10 is fixed to the sleeve 8 and driven thereby to form a low speed pump or impeller. In contrast, a second stage impeller 12 is fixed to and driven by the shaft 6 to form the high speed pump or impeller. The outer ends of the impellers are “free” or unsupported by a surrounding ring, and their ends are tapered rearwardly to define an impeller periphery which complements and is located adjacent to the internal shape of the housing in which it is mounted. (DX-97, p. 3). Moreover, the speed of the second stage impeller is greater than the speed of the first stage impeller, and the cross-sectional area of the impeller housing decreases in a direction approaching the discharge end. The patent application emphasizes that this combination, i.e., (1) the speed of the second stage impeller being greater than the first stage impeller, and (2) the impeller housing decreasing toward the discharge end, results in a very highly desirable high speed pumping unit with a correspondingly high pressure rise through the unit. (DX-97, p. 3, lines 1-5).

[717]*717[[Image here]]

Finally, fixed stator blades 14 are secured within the housing and are located behind the first stage impeller 10, and the hub 14A of these blades forms a support for the sleeve bearing 14B where the rear end of the drive sleeve 8 is rotatably mounted. Fixed stator blades 15 are fixed within the housing and directly behind the second stage impeller while the central hub 15A of these blades contains a sleeve bearing 15B which rotatably supports the rear end of drive shaft 6. These stator blades [718]*718act to “straighten out” the flow of water after it leaves the impellers, that is, they reduce the circular movement or spin of the water and direct it axially rearwardly. (DX-97, p. 4) The housing closely surrounds and complements the peripheral shape of the impellers. (DX-97, p. 4, lines 21-22).

The ’961 patent contains ten claims which read as follows:

1. A multi-stage, hydraulic jet propulsion unit for waterborne craft comprising,

a housing having a forward intake portion for receiving water and a rearward discharge portion for discharging water rearwardly of the stem of the craft,

and said housing having a rearwardly converging portion, a first stage impeller mounted within said converging portion for being rotationally driven,

a second stage impeller mounted within said converging portion and located rear-wardly of and of smaller diameter than said first stage impeller and in co-axial alignment therewith,

said housing closely surrounding said impellers in complementary converging relationship therewith, the flow rate of the water through the first stage impeller being the same as that through said second stage impeller,

and means for rotationally driving said second stage impeller faster than said first stage impeller.

2. A unit as defined in claim 1 including stator blades fixed within said converging portion of said housing,

and located between said impellers,

and also rearwardly of said second stage impeller for straightening out the flow of water.

3. A multi-stage, hydraulic jet propulsion unit for waterborne craft comprising,

a housing having an inlet flush with the bottom of said craft for receiving water,

and a rearwardly and also an upwardly inclined forward portion extending from said inlet,

said housing having an intermediate portion which converges rearwardly, and a rear discharge portion for discharging water rearwardly of the stern of the craft,

a first stage impeller and a second stage impeller both mounted within said converging portion for being rotationally driven,

said second stage impeller located rear-wardly of and of smaller diameter than said first stage impeller and in co-axial alignment therewith,

said housing closely surrounding said impellers in complementary converging relationship therewith,

the flow rate of the water through the first stage impeller being the same as that through said second stage impeller,

and means for rotationally driving said second stage impeller faster than said first stage impeller.

4. A unit as defined in claim 3 including stator blades fixed within said converging housing portion and located rearwardly of each of said impellers.

5. A multi-stage, hydraulic jet propulsion unit for waterborne craft comprising,

a housing having an inlet flush with the bottom of said craft for receiving water,

and a forward portion extending rear-wardly and upwardly from said inlet,

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Cite This Page — Counsel Stack

Bluebook (online)
10 Cl. Ct. 713, 231 U.S.P.Q. (BNA) 417, 1986 U.S. Claims LEXIS 808, Counsel Stack Legal Research, https://law.counselstack.com/opinion/twin-disc-inc-v-united-states-cc-1986.