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US 4,050,359 AGranted
Hydraulic power trim and power tilt system supply
AssigneeBrunswick Corporation
InventorWilliam B. Mayer
Life of this patent
Estimating the term…
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AssigneeBrunswick Corporation
InventorWilliam B. Mayer
Estimating the term…
A hydraulic system for a combined power trim and shock absorbing piston-cylinder unit of an outboard motor includes a reversible pump means having a trim-up port connected by a pressure responsive pilot valve piston cylinder units and a trim-down port through a reverse lock solenoid valve and a down-pilot spool valve providing full drain flow for trim-up and power flow for trim-down. An "up-reverse" pilot valve with a pressure operator is in parallel with the reverse lock valve and provides a restricted by-pass for limited trim-up in reverse. The trim-up hydraulic input or powered side of the cylinder units define a trapped hydraulic system creating "memory" in the system so after impact the motor returns to the original trim position. The return side permits relatively free-flow to permit "trail-out" under low impact. At high speed impact, the flow is restricted and cylinder pressure increases. At a selected point, a shock valve within the piston-cylinder opens and absorbs the shock forces. The piston unit includes an inner floating head telescoped into a head secured to the piston rod with a chamber thereby formed to store the liquid flow during shock movement. A metered orifice and check valve allows return to the original trim-set position.
In a combined trim and shockabsorbing piston-cylinder apparatus comprising a cylinder having end closure walls at the opposite ends, means to supply hydraulic fluid to the opposite ends of said cylinder for oppositely positioning of a shock piston assembly and piston rod, said piston assembly comprising a shock piston slidably mounted within the cylinder with a sliding seal between the periphery of the piston and the cylinder, a piston rod being secured to the piston and extending out of one end of the cylinder, said shock piston having a valve means responsive to shock forces on said piston rod and cylinder to establish a shock absorbing fluid flow from one side to the opposite side of the piston, a trim piston unit located to the cylinder side of the shock piston and slidably sealed to the cylinder, said trim piston unit and shock piston being mounted in releasable telescoped relation to define a variable sized reservoir therebetween to the one side of the shock piston and minimizing the overall length of the piston assembly, whereby said shock piston and said trim piston unit can move together through abutment with one another or be spaced from one another.
Dependencies are inferred from the claim text.