US 2001/0042435 A1Published application

Actuator having internal valve structure

AssigneeDelaware Capital Formation, Inc.

InventorsDon B. Porter, Wayne D. Shapiro

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Abstract

A hydraulic cylinder in which the cylinder head contains the main control valve for the cylinder. In one fluid path from the main control valve to an area located on one side of the cylinder's piston, fluid is directed through a transfer tube that extends through the center of the piston and terminates within a hollow ported section of the piston rod. The cylinder head can additionally include two electrically-actuated pilot valves and two pilot-operated check valves. The pilot-operated check valves are located in different passages that extend to areas located on opposite sides of the piston. The pilot-operated check valves include structure that, in combination with passages in the cylinder head, cause both pilot-operated check valves to open when pressurized fluid is being directed to one of the pilot-operated check valves by the main control valve. In the preferred embodiment, electrical wiring to the cylinder head travels through one of the fluid hoses connected to the cylinder.

Claims14

Dependent claims

A hydraulic cylinder comprising:

an elongated body that inwardly contains a piston that is slidable within an interior cavity of said body, wherein said piston divides said cavity into first and second cavity portions, wherein said piston is attached to a portion of a piston rod, wherein sliding movement of said piston causes said piston rod to move;
a cylinder head located at one end of said body, wherein said cylinder head inwardly contains a main control valve capable of being connected to a source of pressurized fluid, wherein said main control valve is capable of being actuated by a user, and wherein when said valve is connected to a source of pressurized fluid and is then actuated by a user, pressurized fluid will flow from said main control valve through a passage in said cylinder head and into said first cavity portion in said body;
and
wherein said cylinder head also contains first and second pilot-operated check valves, wherein said first pilot-operated check valve is in a fluid path leading to the first cavity portion of said body, wherein said second pilot-operated check valve is in a fluid path leading to the second cavity portion of said body, wherein when said main control valve is actuated in a predetermined manner, pressurized fluid will be directed to both of said pilot-operated check valves to thereby cause both pilot-operated check valves to open and allow pressurized fluid to flow through one of said check valves and continue to one of said cavity portions of said body while also enabling displaced fluid from the other of said cavity portions of said body to flow through the other of said check valves and be directed to a fluid reservoir via a fluid return passage, and wherein causing both of said check valves to open entails sending pressurized fluid to act on an end portion of a movable poppet located in one of said check valves while simultaneously sending pressurized fluid to act on a flange portion of a movable poppet located in the other of said check valves.

1 more element

A hydraulic cylinder comprising:

an elongated body that inwardly contains a piston that is slidable within an interior cavity of said body, wherein said piston divides said cavity into first and second cavity portions, wherein said piston is attached to a portion of an elongated piston rod, wherein sliding movement of said piston causes said piston rod to move in a first axial direction;
and
a cylinder head located at one end of said body and extending outwardly from said body in a direction substantially parallel to said first axial direction, wherein said cylinder head inwardly contains a main control valve, first and second pilot valves, and first and second solenoids, wherein said main control valve and said pilot valves are capable of being connected to a source of pressurized fluid and to a fluid reservoir, wherein said first and second pilot valves are fluidically connected to said main control valve and are each capable of causing movement of a center-biased flow-controlling spool located within said main control valve, wherein said first pilot valve is operatively connected to said first solenoid and said second pilot valve is operatively connected to said second solenoid, wherein when a switch located remote from said hydraulic cylinder is electrically connected to said solenoids and to a power source, and a user actuates said switch in a predetermined manner, said first solenoid will become energized and affect said first pilot valve to cause pressurized fluid to be directed to an area adjacent one end of said spool of said main control valve while fluid in an area adjacent an opposite end of said spool will be directed to a reservoir via said second pilot valve, thereby causing said spool to shift and thereby cause pressurized fluid to be sent into the first cavity portion of said body and cause said piston to move within said body as fluid from said second cavity portion of said body is directed to a reservoir via the main control valve.

Dependencies are inferred from the claim text.

Facts

Application: 09/917,066Filed 26 Jul 2001
Priority: 19 Aug 1999
Published: 22 Nov 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

F15B 1/265
Supply reservoir or sump assemblies: with pressurised main reservoir
F15B 15/18
Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith: combined units comprising both motor…
F15B 15/202
Other details , e.g. assembly with regulating devices: externally-operated valves mounted in or on the actuator
F16D 41/10
With provision for altering the freewheeling action: with self-actuated reversing