Abstract: A lock valve for marine hydraulic steering systems includes a valve body with a spool valve reciprocatingly received in a bore therein. A first port and a second port of the valve are connected to a manual pump. A third port and fourth port are connected to a double acting hydraulic cylinder connected to a rudder or steerable motor. There are valves within the lock valve which normally prevent fluid flowing between the ports so the steering system remains in a fixed position when the helm is released. Fluid can flow from the first port to the third port when the first port is pressurized. A return flow of fluid from the fourth port to the second port is permitted only when the first port is pressurized. When the second port is pressurized, fluid can flow the second port to the fourth port. A return flow of fluid from the third port to the first port is permitted only when the second port is pressurized.

Abstract: A hydraulic steering assembly (10) connected to the tiller arm (24) of an outboard marine engine (22) includes a piston rod (36) supported for arcuate movement about the tilt axis (B) while remaining parallel thereto. A hydraulic cylinder (42) travels along the piston rod (36). An arm (70) extends from the cylinder (42) to a first pivotal member (64) establishing a first pivotal connection about an axis (C) parallel to the tilt axis (B). A rigid link (68) extends between the first pivotal member (64) and a second pivotal member (66). The second pivotal member (66) is also connected to the tiller arm (24) and establishes a second pivotal connection about an axis (D) perpendicular to the tilt axis (B).

Abstract: A manual hydraulic helm pump (10) for actuating a remote submerged steering element in a boat includes a drive shaft (26) rotatably supported in a housing (12). A rotary cylinder block (32) disposed in the housing (12) is fixed to the drive shaft and includes a plurality of axial compression chambers (40). The cylinder block (32) is supported at one end by a roller bearing (34) and at the other end by the drive shaft (26). Each of the compression chambers (40) include a slidable piston (42) biased outwardly against an angular swash plate (50). A spigot-type timing valve (52) is nonrotatably supported within the cylinder block. A transfer valve (59) is fixed relative to the housing (12). A pair of tubular connector sleeves (72a, 72b) movably interconnect the timing valve (52) and the transfer valve (59).

Abstract: A swash plate type hydraulic pumping assembly (10) including a plurality of pistons (28) axially reciprocated in individual chambers (22) of a rotor (20). Each piston (28) includes a hollowed central cavity (30) supporting a compression spring (54) which urges the piston (28) out of the chamber (22) and toward a camming surface (64) of the swash plate (60). A tube (42) is disposed in the chamber (22) adjacent a hydraulic fluid exhaust port (24) and forms the only flow route for fluid entering or exiting the chamber (22). A top surface (34) in the cavity (30) of the piston (28) is spaced from the exhaust port (24) and collects gas inclusions trapped in the fluid during operation. When the piston (28) is moved in the chamber (22) to a fully compressed position, the top spaced surface (34) is very close to the tube (42) allowing the trapped gas inclusions to be swept away from the top spaced surface (34) and out of the pump assembly (10).

Abstract: A closed hydraulic system (10) of the type for steering a boat including a hydraulic cylinder (18) having port and starboard sides (20, 22) and a piston (24) within the cylinder (18) moveable therebetween. A steering pump (12) has first and second fluid outlets (14, 16). Port and starboard hydraulic lines (26, 28) interconnect the port and starboard sides (20, 22) to the first and second outlets (14, 16) respectively, for fluid communication therebetween. A closed separator tank (30) separates air from hydraulic fluid. The tank (30) includes port and starboard tank line (32, 34) in fluid communication with the port and starboard hydraulic lines (26, 28) respectively. The tank (30) includes a bleeder valve mechanism for selectively allowing fluid flow in one direction from the port tank line (32) into the separator tank (30) and out the starboard tank line (34) and alternatively in the opposite direction.

Abstract: A closed hydraulic system (10) of the type for steering a boat including a hydraulic cylinder (18) having port and starboard sides (20, 22) and a piston (24) within the cylinder (18) moveable therebetween. A steering pump (12) has first and second fluid outlets (14, 16). Port and starboard hydraulic lines (26, 28) interconnect the port and starboard sides (20, 22) to the first and second outlets (14, 16) respectively, for fluid communication therebetween. A closed separator tank (30) separates air from hydraulic fluid. The tank (30) includes port and starboard tank .[.line.]. .Iadd.lines .Iaddend.(32, 34) in fluid communication with the port and starboard hydraualic lines (26, 28) respectively. The tank (30) includes a bleeder valve mechanism for selectively allowing fluid flow in one direction from the port tank line (32) into the separator tank (30) and out the starboard tank line (34) and alternatively in the opposite direction.

Abstract: A lock valve for marine hydraulic steering systems includes a valve body with a spool valve reciprocatingly received in a bore therein. A first port and a second port of the valve are connected to a manual pump. A third port and fourth port are connected to a double acting hydraulic cylinder connected to a rudder or steerable motor. There are valves within the lock valve which normally prevent fluid flowing between the ports so the steering system remains in a fixed position when the helm is released. Fluid can flow from the first port to the third port when the first port is pressurized. A return flow of fluid from the fourth port to the second port is permitted only when the first port is pressurized. When the second port is pressurized, fluid can flow the second port to the fourth port. A return flow of fluid from the third port to the first port is permitted only when the second port is pressurized.