Propeller for varying the exhaust length
US5816869A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1997 |
| Grant date | Oct 6, 1998 |
| Priority date | — |
| Expiry date | Jul 15, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB63H20/245
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A propeller for a marine propulsion system that provides variable length exhaust paths depending upon the speed of the boat and motor. The propeller includes a propeller hub and an exhaust tube positioned within the propeller hub. The exhaust tube extends past the aft end of the propeller hub and defines a first exhaust passageway. A second exhaust passageway is positioned between the propeller hub and the exhaust tube. The second exhaust passageway is shorter than the first exhaust passageway. At low speeds, engine exhaust exits the longer first passageway, while at moderate speeds, engine exhaust exits the shorter second passageway. Therefore, the effective length of the exhaust path varies depending upon the speed of the motor, such that the length of the exhaust path is specifically tuned to several speeds of the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.