Interlocked single function activation valve
AssigneeStriped Monkey IP
InventorDaniel James Higgins
Life of this patent
Estimating the term…
Abstract
An interlocked single function activation valve for hydraulic systems is disclosed. The hydraulic valve prevents unsafe tie-down or safety override situations by requiring the safety mechanism to be reset each time the hydraulic system is used. The hydraulic valve includes an interlock spool that moves to an extension position when the hydraulic system is de-pressurized and then re-pressurized while the control lever is engaged (i.e., tied down). When the interlock spool is in the extension position, it prevents the system from reaching a working pressure, thereby forcing a reset of the control lever before the system can reach working pressure.
Claims10
A hydraulic valve assembly for preventing safety override, the hydraulic valve assembly comprising:
- a valve body having a first cylindrical internal cavity and a second cylindrical internal cavity, the cylindrical internal cavities arranged in an in-line configuration along a radial axis;
- a first axially moveable cylindrical spool supported within the first cylindrical cavity, wherein the first spool is attached at one end to a valve control member;
- a second axially moveable cylindrical spool supported within the second cylindrical cavity,
- wherein the second spool contacts the first spool at one end,
- wherein the second spool is an interlock spool having a radially oriented interlock land provided thereon that is coaxial with the interlock spool, and
- wherein the interlock land engages a biasing member providing force in the axial direction toward the control member;
- hydraulic ports defined through the valve body for flow therethrough of hydraulic fluid,
- wherein the hydraulic ports include an inlet port that allows the hydraulic fluid to flow into the hydraulic valve assembly and an outlet port that allows the hydraulic fluid to flow out of the hydraulic valve assembly,
- wherein the hydraulic ports further include a system pressure inlet port and a tank outlet port, and
- wherein, when the control member is engaged, the interlock spool allows flow of the hydraulic fluid from the system pressure port to the tank port, and the flow of the hydraulic fluid from the system pressure port to the tank port prevents the hydraulic system from achieving a working pressure;
- wherein the interlock spool is axially movable between a retention position and an extension position such that when the interlock spool is in the extension position, the interlock land prevents flow of the hydraulic fluid out of the outlet port at a working pressure.
Dependencies are inferred from the claim text.