The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 2000
Filed:
Jul. 31, 1997
Charles F Alexander, Jr, Austin, TX (US);
Daniel F McCormick, Oshkosh, WI (US);
Brunswick Corporation, Lake Forest, IL (US);
Abstract
An improved hydraulic system for a twin propeller marine propulsion unit. A vertical drive shaft is operably connected to the engine of the propulsion unit and carries a pinion that drives a pair of coaxial bevel gears. An inner propeller shaft and an outer propeller shaft are mounted concentrically in the lower torpedo section of the gear case and each propeller shaft carries a propeller. To provide forward movement for the watercraft, a sliding clutch is moved in one direction to operably connect the first of the bevel gears with the inner propeller shaft to drive the rear propeller. A hydraulically operated multi-disc clutch is actuated when engine speed reaches a pre-selected elevated value to operably connect the second of the bevel gears to the outer propeller shaft, to thereby drive the second propeller in the opposite direction. The hydraulic system for actuating the multi-disc clutch includes a pump connected to the inner propeller shaft, and the pump has an inlet communicating with a fluid reservoir in the gear case and has an outlet which is connected through a hydraulic line to the multi-disc clutch. A strainer, a pressure regulator and a valve mechanism are disposed in the lower gear case and are located in series in the hydraulic line. At idle and slow operating speeds the valve is held by a solenoid in a position where the fluid is dumped to the reservoir, so that the pressure of the fluid being directed to the multi-disc clutch is insufficient to engage the clutch. At engine speeds above a preselected value, the solenoid is deenergized and the valve is then biased to a position where the fluid is delivered to the multi-disc clutch to engage the clutch and cause operation of the second propeller.