Rotatable wedge valve mechanism and method for manufacture

1. A rotatable wedge valve mechanism, comprising:

a valve body having a valve chamber and flow ports in fluid communication with said valve chamber;

a valve seat within said valve body;

a core member having convex external surface portions and being located in substantially nonrotatable relation within said valve chamber;

a variable wedge member having rotatable supported engagement with said core member and having a range of rotary motion between open and closed positions of said valve mechanism, said variable wedge member having non-uniform wall thickness throughout said range of rotary motion; and

an actuator achieving opening and closing rotation of said wedge member.

2. The rotatable wedge valve mechanism of claim 1 , comprising:

said variable wedge member having a concave internal surface engaging said convex external surface of said core member and having a convex external surface engaging said valve seat; and

said concave internal surface and said convex external surface each being generated from spaced center-points.

3. The rotatable wedge valve mechanism of claim 1 , comprising:

said wedge member having an external convex surface and an internal concave surface being mounted for rotation within said valve chamber between said core member and said valve seat, said wedge member defining an intermediate wall section of a predetermined thickness located between and merging with wedging wall sections each having a thickness greater than said predetermined thickness.

4. The rotatable wedge valve mechanism of claim 3 , comprising:

said wedging wall sections having substantially the same wall thickness.

5. The rotatable wedge valve mechanism of claim 3 , comprising:

said wedging wall sections having wall thickness of differing dimension.

6. The rotatable wedge valve mechanism of claim 3 , comprising:

said wedge member being rotatably positionable at open and closed positions;

said external convex surface having an intermediate position with said intermediate wall section of a predetermined thickness being located in facing relation with said valve seat and having low interference wedging force engagement with said valve seat; and

said external convex surface having open and closed wedging positions with said wedging wall sections applying sealing force of said external convex surface with said valve seat.

7. The rotatable wedge valve mechanism of claim 1 , comprising:

said wedge member having a trunnion member projecting therefrom, said trunnion member supporting a part of said wedge member for rotation within said valve chamber; and

said concave internal surface and said convex external surface and said trunnion member each being generated from independent center-points.

8. The rotatable wedge valve mechanism of claim 7 , comprising:

a valve stem projecting from said wedge member and having supported rotatable engagement with said valve body.

9. A rotatable wedge valve mechanism, comprising:

a valve body defining a valve cartridge chamber and having flow ports in fluid communication with said valve cartridge chamber;

a cartridge housing being replaceably positioned and sealed within said cartridge chamber and having flow ports in registry with said flow ports of said valve body;

a valve seat within said cartridge housing;

a core member having generally convex external surface portions being located in substantially nonrotatable relation within said cartridge chamber;

a wedge valve member having a range of rotary motion between open and closed positions of said valve mechanism and having non-uniform wall thickness throughout said range of rotary motion; and

an actuator having rotary driving engagement with said wedge valve member and achieving opening and closing rotation of said wedge valve member.

10. The rotatable wedge valve mechanism of claim 9 , comprising:

said wedge valve member having a generally spherical internal surface engaging said convex external surface of said core member and having a convex external surface engaging said valve seat; and

said internal generally spherical surface and said convex external surface being generated from spaced center-points.

11. The rotatable wedge valve mechanism of claim 9 , comprising:

said wedge valve member having an external convex surface and an internal concave surface being mounted for rotation within said valve chamber between said core member and said valve seat, said wedge member defining an intermediate wall section of a predetermined thickness located between and transitioning gradually with wedging wall sections each having a thickness greater than said predetermined thickness.

12. The rotatable wedge valve mechanism of claim 11 , comprising:

said wedge valve member being rotatably positionable at open and closed positions;

said external convex surface having an intermediate position with said intermediate wall section of a predetermined thickness being located in facing relation with said valve seat and providing clearance permitting less wedging force against said valve seat; and

said external convex surface having open and closed wedging positions with said wedging wall sections applying sealing force of said external convex surface to said valve seat.

13. The rotatable wedge valve mechanism of claim 9 , comprising:

said wedge valve member having a trunnion member projecting therefrom, said trunnion member supporting a part of said wedge member for rotation within said valve chamber; and.

a valve stem projecting from said wedge member and having supported rotatable engagement with said valve body.

14. The rotatable wedge valve mechanism of claim 13 , comprising:

said trunnion member and sand valve stem being integral with said wedge valve member and each being rotatably supported by said cartridge housing.

15. The rotatable wedge valve mechanism of claim 9 , comprising:

a bonnet member being mounted to said cartridge housing and being adapted for secure sealed connection with said valve body.

16. The rotatable wedge valve mechanism of claim 9 , comprising:

a bonnet member being adapted for secure sealed connection with said valve body and securing said rotatable wedge valve cartridge within said cartridge chamber of said valve body.

17. A method for manufacturing a rotatable wedge valve member, comprising:

generating a substantially spherical concave surface on a valve member workpiece from a first center-point:

generating a substantially spherical convex surface on the valve member workpiece from a second center-point being spaced from said first center-point to establish an intermediate valve member thickness and leading and trailing valve member thicknesses that merge with said intermediate valve member thickness being of different thickness as compared with said leading and trailing valve member thicknesses.

18. The method of claim 17 , wherein a trunnion member projects from said rotatable rotatable wedge valve member and provides rotational support therefore, said method comprising:

generating a trunnion member from a third center-point being independent from said first and second center-points; and

establishing desired relative positions of said first, second and third center-points and determining the geometric relationships of said substantially spherical concave and convex surfaces of said rotatable wedge valve member.

19. The method of claim 17 , comprising:

establishing intersection first and second reference lines having 90° intersection, the intersection thereof defining a first center-point;

generating said substantially spherical concave surface from said first center-point;

establishing a second center-point being off-set from said first center-point and being on said first reference line; and

generating said substantially spherical convex surface from said second center-point.

20. The method of claim 17 , comprising:

establishing intersection first and second reference lines having 90° intersection, the intersection thereof defining a first center-point;

generating said substantially spherical concave surface from said first center-point;

establishing a second center-point being off-set from said first center-point and being off-set from said first and second reference lines; and

generating said substantially spherical convex surface from said second center-point.