Flapper valve with independent spring action

Abstract

An improvement in multi-flapper check valves wherein each flapper is urged toward closure by an independent spring or springs, thereby improving the valve response for closure.

I claim: 
     
       1. An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, stationary shaft means extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft means, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said shaft means for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means, .Iadd.said stop means comprising a pin member extending diametrically across said flow conduit parallel to said shaft means at a location spaced from said valve members to limit movement of said valve members in an opening direction. .Iaddend. 
     
     
       2. The improved valve of claim 1 in which at least two of said helical torsion springs have different torsional spring constants. .[.3. An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a shaft for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said shaft, wherein the improvement comprises at least one separate helical torsion spring wound about said shaft for each valve member, one leg of said spring being in contact with said valve member and the other leg being in contact with a stationary stop shaft..]. .[.4. The improved valve of claim 3 in which at least two of said helical torsion 
     
     
        springs exert different amounts of force per degree of deflection..]. 5. An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said flow conduit, a single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a stationary stop means, .Iadd.said stop means comprising a pin member extending diametrically across said flow conduit parallel to said stationary shaft at a location spaced from said valve members to limit movement of said valve members in an opening direction. .Iaddend. .[.6. An improved valve of the type having a body with a fluid flow conduit therethrough, a valve seat surrounding said flow conduit, valve members for sealing said fluid flow conduit, a first single stationary shaft extending diametrically across said flow conduit for pivotally supporting said valve members within said body, and hinges for supporting said valve members on said first stationary shaft, wherein the improvement comprises at least one separate helical torsion spring encircling a portion of said first stationary shaft for each valve member for biasing said valve member toward its closed position, one leg of which is in contact with said valve member and the other leg of which is in contact with a second shaft parallel to said first stationary shaft..].