Gripping wedge for pipe joint restraint

1 . A gripping wedge for a pipe joint restraint, the gripping wedge comprising:

a first surface extending in a first plane;

a groove formed in the first surface, the groove having first and second curvatures;

wherein the first curvature extends in the first plane;

wherein the second curvature extends in a second plane; and

wherein the second plane is perpendicular to the first plane; and

a first projection at least a portion of which is offset from the first surface in a direction perpendicular to the first plane;

wherein the first projection is adjacent the groove such that, in the first plane, at least a portion of the groove is positioned between the first projection and the first surface;

wherein the first projection has third and fourth curvatures;

wherein the third curvature of the first projection is coaxial with the first curvature of the groove;

wherein the fourth curvature of the first projection extends in a third plane;

wherein the third plane is perpendicular to each of the first and second planes; and

wherein the first projection is adapted to dig into a pipe being restrained by the pipe joint restraint.

2 . The gripping wedge of claim 1 , wherein the extension of the fourth curvature of the first projection, in the third plane that is perpendicular to each of the first and second planes, opposes the curvature of the pipe.

3 . The gripping wedge of claim 2 , wherein the opposing curvatures of the pipe and the first projection provide gap(s) between the first projection and the pipe adapted to receive material displaced from the pipe when the first projection digs into the pipe.

4 . The gripping wedge of claim 1 , wherein the groove is adapted to receive material displaced from the pipe when the first projection digs into the pipe.

5 . The gripping wedge of claim 1 , wherein the third curvature of the first projection extends in the first plane that is perpendicular to each of the second and third planes.

6 . The gripping wedge of claim 1 , wherein the groove includes a fifth curvature extending in the third plane that is perpendicular to each of the first and second planes.

7 . The gripping wedge of claim 1 , further comprising:

a ledge opposing the first surface in the first plane and adapted to be engaged by a fastener of the pipe joint restraint to urge the gripping wedge, including the first projection, against the pipe.

8 . The gripping wedge of claim 7 ,

wherein the ledge is inclined in the second plane that is perpendicular to each of the first and third planes.

9 . The gripping wedge of claim 1 , further comprising:

a second projection at least a portion of which is offset from the first surface in a direction perpendicular to the first plane;

wherein the second projection is adjacent the first surface such that, in the first plane, the at least a portion of the groove is positioned between the first projection and the second projection.

10 . The gripping wedge of claim 9 ,

wherein the second projection has fifth and sixth curvatures;

wherein the fifth curvature of the second projection is coaxial with the first curvature of the groove and with the third curvature of the first projection; and

wherein the sixth curvature of the second projection extends in the third plane that is perpendicular to each of the first and second planes.

11 . The gripping wedge of claim 9 ,

wherein the second projection is adjacent the first surface such that, in the first plane, at least a portion of the first surface is positioned between the groove and second projection.

12 . The gripping wedge of claim 1 , further comprising:

a second surface extending in the first plane;

wherein the second surface is adjacent the first projection opposite the groove such that, in the first plane, at least a portion of the first projection is positioned between the second surface and the groove; and

a third projection at least a portion of which is offset from the first and second surfaces in a direction perpendicular to the first plane;

wherein the third projection is adjacent the second surface opposite the first projection such that, in the first plane, at least a portion of the second surface is positioned between the first and third projections.

13 . The gripping wedge of claim 12 , wherein the third projection is adapted to urge the gripping wedge to pivot about the first projection.

14 . The gripping wedge of claim 1 , further comprising:

a third surface adjacent to the first surface and extending in the second plane that is perpendicular to each of the first and third planes such that the third surface extends perpendicular to the first surface; and

a channel formed in the third surface;

wherein the channel includes a seventh curvature extending in the first plane;

wherein the channel is adapted to receive an adhesive; and

wherein the adhesive is adapted to retain the gripping wedge within the pipe joint restraint.

15 . A restraint apparatus for a pipe joint, the restraint apparatus comprising:

a joint restraint comprising a housing;

a fastener engaged with the joint restraint, the fastener comprising a distal end portion adapted to be received within the housing of the joint restraint; and

a gripping wedge received within the housing of the joint restraint and adapted to be engaged by the distal end portion of the fastener;

wherein the gripping wedge comprises:

a first surface;

a groove formed in the first surface, the groove having first and second curvatures;

wherein the first curvature extends in a first plane;

wherein the second curvature extends in a second plane; and

wherein the second plane is perpendicular to the first plane;

a projection at least a portion of which is offset from the first surface;

wherein the projection is adjacent the groove so that at least a portion of the groove is positioned between the projection and the first surface;

wherein the projection has a third curvature;

wherein the third curvature of the projection is coaxial with the first curvature of the groove; and

wherein the projection is adapted to dig into a pipe being restrained by the restraint apparatus; and

an inclined ledge opposing the first surface in the first plane and adapted to be engaged by the distal end portion of the fastener;

wherein the inclined ledge defines a fourth curvature, the fourth curvature extending within the second plane; and

wherein the inclined ledge, including the fourth curvature, permits the gripping wedge to pivot, about the distal end portion of the fastener as the projection digs into the pipe being restrained by the restraint apparatus, and prevents, or at least resists, over-rotation of the gripping wedge.

16 . The restraint apparatus of claim 15 , wherein the at least a portion of the projection is radially offset from the first surface.

17 . The restraint apparatus of claim 15 ,

wherein the first surface extends in a third plane that is perpendicular to each of the first and second planes; and

wherein the at least a portion of the projection is offset from the first surface in a direction perpendicular to the first plane and in a direction perpendicular to the third plane.

18 . The restraint apparatus of claim 17 , wherein the at least a portion of the groove is positioned between the projection and the first surface in the third plane.

19 . The restraint apparatus of claim 17 ,

wherein the projection further includes a fifth curvature; and

wherein the fifth curvature of the projection extends in the third plane.

20 . The restraint apparatus of claim 15 , wherein the at least a portion of the groove is positioned between the projection and the first surface in the second plane.