Hydraulic system for a boat drive

Claim 2

In a boat drive unit including a steerable and tiltable outboard power leg, a mounting member for said leg fixed to the boat, said leg comprising a propeller housing including an underwater portion provided with a propeller, a support member and means supportedly connecting said propeller housing to said support member for rotation of said housing on a generally upright steering axis, means supportedly connecting said support member to said mounting member for tilting of said leg on a generally horizontal tilt axis in a rearward direction of increasing tilt angle and in a forward direction of decreasing tilt angle, a hydraulic control system for said leg comprising, a hydraulic expansible chamber device spanning said tilt axis and operatively connected between said mounting member and said support member, a steering cylinder assembly comprising a cylinder fixed to said support member and double acting piston means disposed in said cylinder, means operatively coupling said piston means to said propeller housing offset from said steering axis, a source of hydraulic liquid under pressure, a sump for supplying liquid to said source, steering control means connecting between said source and said cylinder assembly including a valve and an outlet conduit, said valve having a rest position in which said source is connected to said outlet conduit, a port steering position in which said source is connected into one of said chambers and said outlet conduit is connected to the other of said chambers, and a starboard steering position in which said source is connected into said other chamber and said outlet conduit is connected to said one chamber, a three way manually controlled valve connected to said conduit to receive pressure liquid therefrom and in a first position of said three way valve to supply said fluid to a pump-up side of said expansible chamber device to power tilt said leg in said rearward direction, in a second position to seal off said side thereby to restrain said leg against forward tilting and to connect said conduit to said sump, and in its third position to connect said side and said conduit to said sump thereby to release said leg for forward movement on said axis.

Claim 3

In a boat drive unit including a steerable and tiltable outboard leg, a mounting member for said leg fixed to the boat, said leg comprising a propeller housing including an underwater portion provided with a propeller, a support member and means supportedly connecting said propeller housing to said support member for rotation of said housing on a generally upright steering axis, means supportedly connecting said support member to said mounting member for tilting of said leg on a generally horizontal tilt axis in a rearward direction of increasing tilt angle and in a forward direction of decreasing tilt angle, a hydraulic control system for said leg comprising, a hydraulic expansible chamber device spanning said tilt axis and operatively connected between said mounting member and said support member and adapted to tilt said leg upon the supplying of hydraulic fluid under pressure thereto, double acting hydraulic cylindeR and piston means operatively coupled between said support member and said propeller housing, said last means including two conduits and operative upon supply of pressure liquid into one of said conduits to swing said propeller housing to port and to supply pressure liquid through said other conduit, and upon supply of pressure liquid into said other conduit to swing said propeller housing to starboard and to supply pressure liquid through said one conduit, a hydraulic liquid sump, a hydraulic pressure pump connected to said sump, a fluid return line connected into said sump, steering control valve means connected to said pump, to said conduits and to said return line, said valve means being operative selectively (1) to supply pressure liquid from said pump to said one conduit and to connect said other conduit to said return line, (2) to supply pressure liquid to said other conduit and to connect said one conduit to said return line, and (3) to seal said conduits and to supply pressure liquid from said pump to said return line thereby to fix said propeller housing with respect to said support member, and a tilt control valve interposed in said return line operable into selective positions (1) to divert pressure liquid therefrom into said expansible chamber device thereby to tilt said leg, (2) to seal off said device thereby to retain the leg in its position of tilt, and (3) to connect said device to said sump thereby to reduce the tilt angle of said leg.

Claim 4

In a boat drive unit including a steerable and tiltable outboard leg, a mounting member for said leg fixed to the boat, said leg comprising a propeller housing including an underwater portion provided with a propeller, a support member and means supportedly connecting said propeller housing to said support member for rotation of said housing on a generally upright steering axis, means supportedly connecting said support member to said mounting member for tilting of said leg on a generally horizontal tilt axis in a rearward direction of increasing tilt angle and in a forward direction of decreasing tilt angle, a hydraulic control system for said leg comprising, a hydraulic expansible chamber device spanning said tilt axis and operatively connected between said mounting member and said support member and adapted to tilt said leg upon the supplying of hydraulic fluid under pressure thereto, double acting hydraulic cylindeR and piston means operatively coupled between said support member and said propeller housing, said last means including two conduits and operative upon supply of pressure liquid into one of said conduits to swing said propeller housing to port and to supply pressure liquid through said other conduit, and upon supply of pressure liquid into said other conduit to swing said propeller housing to starboard and to supply pressure liquid through said one conduit, a hydraulic liquid sump, a hydraulic pressure pump connected to said sump, a fluid return line connected into said sump, steering control valve means connected to said pump, to said conduits and to said return line, said valve means being operative selectively (1) to supply pressure liquid from said pump to said one conduit and to connect said other conduit to said return line, (2) to supply pressure liquid to said other conduit and to connect said one conduit to said return line, and (3) to seal said conduits and to supply pressure liquid from said pump to said return line thereby to fix said propeller housing with respect to said support member, and a tilt control valve interposed in said return line operable into selective positions (1) to divert pressure liquid therefrom into said expansible chamber device thereby to tilt said leg, (2) to seal off said device thereby to retain the leg in its position of tilt, and (3) to connect said device to said sump thereby to reduce the tilt angle of said leg.

Claim 5

In a marine propulsion mechanism, the combination with mounting bracket means adapted to be secured to a boat and a propulsion unit pivotally connected to the mounting bracket means on a horizontal transverse axis to provide for tilt movement of the unit in a generally vertical plane, an extensible power tilt unit comprising a double acting hydraulic liquid filled cylinder having a piston therein dividing said cylinder into first and second enclosed chambers, a piston rod connected to said cylinder through said second chamber thereof, said tilt unit being connected between said bracket means and said propulsion unit spanning and below said axis thereby to tilt up said propulsion unit upon extension thereof and to be extended upon tilting up of said propulsion unit from the imposition of an external force thereto, a pressure relief valve having a predetermined operating pressure connected from said first chamber to said second chamber, means including a control valve, a liquid sump and a pump to supply hydraulic liquid from said sump under pressure from the pump outlet, a shut off valve disposed between said second chamber and said pressure relief valve, a second pressure relief valve operative at a pressure substantially greater than the operative pressure of said first relief valve connected from said second chamber to said first chamber, said control valve having a first position connecting the outlet of said pump to supply pressure liquid to said first chamber, a second position to seal off said first chamber thereby to restrain said unit against contraction and to connect said pump outlet to said sump, and a third position connecting said first chamber and said pump outlet to said sump, and a check valve connected from said sump to said shut off valve oriented to pass hydraulic liquid from said sump to said second chamber through said shut off valve when the shut off valve is open and when said piston is moving in a direction to increase the volume of said second cylinder.

Claim 6

In a marine propulsion mechanism, the combination with mounting bracket means adapted to be secured to a boat and a propulsion unit pivotally connected to the mounting bracket means on a horizontal transverse axis to provide for tilt movement of the unit in a generally vertical plane, an extensible power tilt unit comprising a double acting hydraulic liquid filled cylinder having a piston therein dividing said cylinder into first and second enclosed chambers, a piston rod connected to said cylinder through said second chamber thereof, said tilt unit being connected between said bracket means and said propulsion unit spanning and below said axis thereby to tilt up said propulsion unit upon extension thereof and to be extended upon tilting up of said propulsion unit from the imposition of an external force thereto, a pressure relief valve having a predetermined operating pressure connected from said first chamber to said second chamber, means including a control valve, a liquid sump and a pump to supply hydraulic liquid from said sump under pressure from the pump outlet, a shut off valve disposed between said second chamber and said pressure relief valve, a second pressure relief valve operative at a pressure substantially greater than the operative pressure of said first relief valve connected from said second chamber to said first chamber, said control valve having a first position connecting the outlet of said pump to supply pressure liquid to said first chamber, a second position to seal off said first chamber thereby to restrain said unit against contraction and to connect said pump outlet to said sump, and a third position connecting said first chamber and said pump outlet to said sump, and a check valve connected from said sump to said shut off valve oriented to pass hydraulic liquid from said sump to said second chamber through said shut off valve when the shut off valve is open and when said piston is moving in a direction to increase the volume of said second cylinder.

Claim 7

A trimming and tilting system for a boat outboard power leg including a fixed mounting member and a leg support member connected thereto by means establishing a horizontal tilt axis for the leg, said system being of the type comprising an extensible cylinder and piston assembly connected between said members spanning said axis, a hydraulic liquid sump and a pump connected to said means for supplying hydraulic liquid under pressure, said system being characterized in said assembly including a rod connecteD to said piston and extending through one end of said cylinder and occupying a substantial volume in said cylinder between said piston and said end, a pressure relief valve, a reverse lock valve, respective conduits connecting said relief valve to said one and the other ends of said cylinder, said relief valve being oriented to pass liquid under pressure from said one to the other of said ends, said lock valve being connected in one of said conduits and having an open position to permit flow of liquid through said relief valve and a closed position to prevent such flow, a check valve connected between said sump and said one end of said cylinder and oriented to pass liquid from said sump to said one end and to prevent passage of liquid from said one end into said sump, manually operable valve means, respective conduit connections from said valve means to said sump, to said other end and to said pump, said valve means having a first position opening said connection from said other end to said pump connection whereby said pump supplies liquid under pressure into said other end, a second position sealing said other end connection, and a third position opening said other end connection into said sump connection.

Claim 8

A trimming and tilting system for a boat outboard power leg including a fixed mounting member and a leg support member connected thereto by means establishing a horizontal tilt axis for the leg, said system being of the type comprising an extensible cylinder and piston assembly connected between said members spanning said axis, a hydraulic liquid sump and a pump connected to said means for supplying hydraulic liquid under pressure, said system being characterized in said assembly including a rod connecteD to said piston and extending through one end of said cylinder and occupying a substantial volume in said cylinder between said piston and said end, a pressure relief valve, a reverse lock valve, respective conduits connecting said relief valve to said one and the other ends of said cylinder, said relief valve being oriented to pass liquid under pressure from said one to the other of said ends, said lock valve being connected in one of said conduits and having an open position to permit flow of liquid through said relief valve and a closed position to prevent such flow, a check valve connected between said sump and said one end of said cylinder and oriented to pass liquid from said sump to said one end and to prevent passage of liquid from said one end into said sump, manually operable valve means, respective conduit connections from said valve means to said sump, to said other end and to said pump, said valve means having a first position opening said connection from said other end to said pump connection whereby said pump supplies liquid under pressure into said other end, a second position sealing said other end connection, and a third position opening said other end connection into said sump connection.

Claim 9

In a boat drive unit including an outboard leg comprising an upper housing portion and a steerable lower propeller housing portion rotatably mounted on said upper portion for rotation on a generally upright steering axis, hydraulic cylinder means, unitary piston means in said cylinder means, said cylinder means having closed ends and said piston means being double acting therein, said cylinder means and piston means being operatively connected between said housing portions for steering movement of said lower portion on said axis in response to movement of said piston means with respect to said cylinder means, said piston means being provided with a port normally closed by a wall portion of said cylinder means and opened upon maximum movement of the piston means outwardly of one end chamber of said cylinder means, and conduit means in said piston means extending from said port and connecting said one end chamber into the other end chamber of said cylinder means when said port is open, a liquid sump, a hydraulic pump connected to said sump, and valve means connected to said pump and to said sump for selectively supplying liquid under pressure from said pump into said one and said other end chambers of said cylinder means and for concurrently connecting the respectively opposite end chamber into said sump.

Claim 10

In a boat drive unit including an outboard leg comprising an upper housing portion and a steerable lower propeller housing portion rotatably mounted on said upper portion for rotation on a generally upright steering axis, hydraulic cylinder means, unitary piston means in said cylinder means, said cylinder means having closed ends and said piston means being double acting therein, said cylinder means and piston means being operatively connected between said housing portions for steering movement of said lower portion on said axis in response to movement of said piston means with respect to said cylinder means, said piston means being provided with a port normally closed by a wall portion of said cylinder means and opened upon maximum movement of the piston means outwardly of one end chamber of said cylinder means, and conduit means in said piston means extending from said port and connecting said one end chamber into the other end chamber of said cylinder means when said port is open, a liquid sump, a hydraulic pump connected to said sump, and valve means connected to said pump and to said sump for selectively supplying liquid under pressure from said pump into said one and said other end chambers of said cylinder means and for concurrently connecting the respectively opposite end chamber into said sump.

Claim 11

The combination according to claim 5 wherein said valve means comprises a pair of relatively movable members provided with registering ports and liquid conduits, said members having a neutral first relative position in which said source is connected to said sump and said chambers are sealed off, a port steering second relative position in which said members are displaced in one direction from said neutral relative position and in which said one end chamber is connected to said source and said other end chamber is connected to said sump, and a starboard steering third relative position in which said members are displaced in the respectively opposite direction from said neutral relative position and in which said other end chamber is conndcted to said source and said one end chamber is connected to said sump, manually operative means for displacing one of said members from said neutral position selectively in said directions, and means operated by liquid flow through said valve means to move the other of said members in a follow-up direction in response to displacement of said members from said neutral position.

Claim 12

The combination according to claim 5 wherein said conduit means is provided with a check valve oriented to block liquid flow from said other end chamber into said one end chamber.

Claim 13

The combination according to claim 5 wherein said valve means comprises a pair of relatively movable valve members for cooperatively controlling the flow to and from said End chambers and having a neutral position, one of said members being manually movable, and means responsive to said flow for moving said other member in a follow-up direction.