# US 5,342,227 A · Water jet propulsion unit

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- Number: US 5,342,227 A
- Document ID: US5342227A
- Status: Granted
- Kind: A
- Application number: 08/048,477
- Filed: 1993-04-16
- Granted: 1994-08-30
- Earliest claimed: 1992-05-27
- Assignees: Sanshin Kogyo Kabushiki Kaisha
- Inventors: Noboru Suganuma
- Web page: https://patentgrep.com/patent/US5342227A

## CPC

- B63H 11/08: of rotary type
- B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00)

## Abstract

A water jet propulsion unit for a watercraft including a separator for extracting a portion of the water pumped by the jet propulsion unit for another purpose while removing foreign particles from the separated water and returning them to the jet propulsion unit to avoid clogging of the external water supply.

## Claims

### Claim 1

A water jet propulsion unit for a watercraft comprising a water inlet portion defining a water inlet through which water may be drawn from the body of water in which the watercraft is operating, an impeller portion containing an impeller for pumping water and a discharge nozzle portion through which water pumped by said impeller is discharged for propelling the watercraft, a separator device for separating foreign particles from said water, an inlet opening communicating said separator device with a side of said jet propulsion unit for receiving a portion of the water pumped by said impeller and returning the separated particles to said jet propulsion unit, and outlet opening for receiving the water from which particles have been separated, and means defining a flow path from said inlet opening to said outlet opening including a horizontally extending portion terminating at a wall disposed in confronting relation to said inlet opening to turn and redirect the flow of water from said horizontally extending portion vertically along said side of said jet propulsion unit for reducing the velocity of water and particles passing through said inlet opening.

### Claim 2 (depends on 1)

A water jet propulsion unit as set forth in claim 1 wherein the inlet is positioned vertically beneath the outlet.

### Claim 3 (depends on 2)

A water jet propulsion unit as set forth in claim 2 further including baffle means extending across portions of the flow path of the separator device.

### Claim 4 (depends on 3)

A water jet propulsion unit as set forth in claim 3 wherein the inlet is defined in part by an inclined lower wall integrally formed with the vertically extending wall and for obscuring a further portion of the inlet area for removing larger particles and for returning separated particles to the jet propulsion unit.

### Claim 5 (depends on 3)

A water jet propulsion unit as set forth in claim 3 wherein the baffle means comprises a plurality of baffles that provide staggered openings for defining a labyrinthine flow path through the separator.

### Claim 6 (depends on 5)

A water jet propulsion unit as set forth in claim 5 wherein the inlet is defined in part by an inclined lower wall integrally formed with the vertically extending wall and for obscuring a further portion of the inlet area for removing larger particles and for returning separated particles to the jet propulsion unit.

### Claim 7 (depends on 6)

A water jet propulsion unit as set forth in claim 6 wherein the separator device has an internal cavity with an area substantially greater than the area of the inlet opening for reducing the velocity of the water flowing through the separator device.

### Claim 8 (depends on 1)

A water jet propulsion unit as set forth in claim 1 wherein the separator device has an internal cavity with an area substantially greater than the area of the inlet opening for reducing the velocity of the water flowing through the separator device.