# US 2016/0251069 A1 · A marine propulsion unit and a valve for a marine propulsion unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0251069 A1 - Document ID: US20160251069A1 - Status: Published application - Kind: A1 - Application number: 15/029,756 - Filed: 2014-10-17 - Published: 2016-09-01 - Earliest claimed: 2013-10-17 - Assignees: E.P. Barrus Limited - Applicants: E.P. Barrus Limited - Inventors: David Phillip ETHERINGTON-SMITH - Web page: https://patentgrep.com/patent/US20160251069A1 ## CPC - B63H 21/38: Apparatus or methods specially adapted for use on marine vessels, for handling power plant or unit liquids, e.g. lubricants, coolants, fuels or the like ({in outboard drives B63H20/001; } lubricating or cooling machines or engines in general F01 - F04) - B63H 21/14: relating to internal-combustion engines {(of outboard type B63H20/00)} - F02B 61/045: {for marine engines} - F02B 77/08: Safety, indicating, or supervising devices (thermal insulation F02B77/11; monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00) - F02N 19/00: Starting aids for combustion engines, not otherwise provided for - F02N 19/004: {Aiding engine start by using decompression means or variable valve actuation} - B63H 20/001: {Arrangements, apparatus and methods for handling fluids used in outboard drives (for handling exhaust gas B63H20/24; for handling cooling-water B63H20/28; cooling outboard marine engines F01P3/202; air intakes for outboard marine engines F02M35/167)} - F01L 1/32: characterised by the provision of means for rotating lift valves, e.g. to diminish wear - F01L 2003/258: {opening away from cylinder} - F02B 2075/025: {two} - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02N: STARTING OF COMBUSTION ENGINES; STARTING AIDS FOR SUCH ENGINES, NOT OTHERWISE PROVIDED FOR - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES ## Abstract A valve for a marine propulsion unit comprises a valve body (11) having an end face (13) and a wall (14) extending from the end face. An aperture (15) is defined in the end face. A valve stem (12) is moveable within and with respect to the valve body, such that, in the closed state of the valve, the valve stem closes the aperture. A maximum width (d1) of the valve stem is greater than the width (d2) of the aperture in the end face of the valve—so that, if the valve stem should fracture, the detached portion(s) of the valve stem will be retained in the valve body. The valve may for example be used as a cylinder drain valve in a marine propulsion unit. ## Claims ### Claim 1 A valve for a marine propulsion unit, the valve comprising: a valve body having an end face and a wall extending from the end face, an aperture being defined in the end face; and a valve stem moveable within and with respect to the valve body, the valve stem having a sealing portion located within the valve body in both an open state and a closed state of the valve, wherein, in the closed state of the valve, the sealing portion of the valve stem abuts against an inner surface of the end face and thereby closes the aperture; and wherein a maximum width of the valve stem is greater than the width of the aperture in the end face of the valve. ### Claim 2 (depends on 1) A valve as claimed in claim 1 wherein the sealing portion of the valve stem comprises a sealing face provided on the valve stem, the sealing face abutting against the circumference of the aperture when the valve is in the closed state. ### Claim 3 (depends on 2) A valve as claimed in claim 2 wherein the sealing face is a frusto-conical sealing face. ### Claim 4 (depends on 1) A valve as claimed in claim 1 wherein, when the valve is in the closed state, an end of the valve stem is substantially flush with the outer surface of the end face of the valve body. ### Claim 5 (depends on 1) A valve as claimed in claim 1, wherein, in the closed state of the valve, the valve stem does not project beyond the outer surface of the end face of the valve body. ### Claim 6 (depends on 2) A valve as claimed in claim 2, wherein the valve stem comprises a portion extending beyond the sealing portion, the portion, when the valve is in a closed state, extending into the aperture in the end face. ### Claim 7 (depends on 1) A valve as claimed in claim 1 wherein rotation of the valve stem relative to the valve body causes the valve to change from the closed state to an open state. ### Claim 8 (depends on 1) A marine propulsion unit comprising: a cylinder; a combustion chamber extending from a first end of the cylinder; a spark plug disposed within the combustion chamber; and a piston reciprocably moveable within the cylinder; wherein the unit further comprises a valve as defined in claim 1, the valve being selectively openable independent of the position of the piston within the cylinder, the valve being positioned such that, in its open state, movement of the piston causes gas within the propulsion unit to flow over the spark plug and subsequently to flow out of the propulsion unit through the first aperture. ### Claim 9 (depends on 8) A propulsion unit as claimed in claim 8 wherein the valve provided within the combustion chamber. ### Claim 10 (depends on 9) A propulsion unit as claimed in claim 9 wherein the end face of the valve body is flush or substantially flush with an internal face of a wall of the combustion chamber.