Unlockable check valve, particularly for use as recovery and setting valve in underground mining
AssigneeThyssen Industrie AG
InventorSiegmar Block
Life of this patent
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Abstract
An improved valve in use for underground mining in connection with a piston cylinder unit, such as a hydraulic prop, is disclosed. The valve includes a piston member within a control chamber which is operative to terminate fluid communication between the hydraulic prop and a hydraulic fluid source. The piston is pressure-equalized in a neutral position when the hydraulic prop is set.
Claims6
An improved valve for use in underground mining in connection with a piston cylinder unit having a member slidably mounted in the bore of the cylinder for displacement responsive to fluid pressure in a first and second compartments in the cylinder on opposite sides of the member comprising
- an elongated housing having a control chamber, a valve chamber, and an outlet chamber intermediate said control chamber and said valve chamber,
- a piston member slidably mounted for axial displacement within said control chamber in fluid-sealing contact with said housing to divide said control chamber into a first control chamber portion and a second control chamber portion,
- first spring means within said second control chamber portion for resiliently biasing said piston member in a first direction toward said first control chamber portion,
- first channel means for establishing fluid communication between the first compartment and said first control chamber portion,
- second channel means for establishing a path of fluid communication between said second compartment and said outlet chamber through said valve chamber,
- shutoff means in said valve chamber for closing said path, said shutoff means being operative responsive to the displacement of said piston member in a second direction opposite said first direction over a first predetermined distance to open said path,
- connection means for establishing fluid communication between said second control chamber portion and said outlet chamber, said piston member being displaceable in said second direction over a second predetermined distance less than said first predetermined distance to shutoff fluid communication between said second control chamber portion and said outlet chamber, said connection means fluidly interconnecting said second control chamber portion and said outlet chamber when said piston member is in a neutral position disposed at a distance in said second direction less than said second predetermined distance.
Dependencies are inferred from the claim text.