Golf club head with improved mass distribution

1. An iron-type or putter-type golf club head comprising:

a striking wall having a front surface and a rear surface;

a heel portion and an opposing toe portion;

a top portion extending from the heel portion to the toe portion; and

a sole portion opposite the top portion and extending from the heel portion to the toe portion, the sole portion including a forward end, a rearward end, an upper surface, and a lower surface including an outer periphery having a contour, the intersection of the upper surface of the sole portion and the rear surface of the striking wall defining an interior sole line, the intersection of the upper surface of the sole portion and the rearward end of the sole portion defining a trailing-edge sole line,

wherein:

at least a portion of the trailing-edge sole line follows a flattened V-shaped path when viewed in rear elevation; and

in an imaginary vertical plane substantially perpendicular to the front surface of the striking wall, when the golf club head is oriented in an address position, the interior sole line is below the trailing-edge sole line and the upper surface of the sole portion tapers from the trailing-edge sole line to the interior sole line.

2. The golf club head of claim 1 , wherein the interior sole line generally follows the contour of the outer periphery of the lower surface of the sole portion when viewed in rear elevation.

3. The golf club head of claim 1 , further comprising an insert coupled to the rear surface of the striking wall.

4. The golf club head of claim 3 , wherein the insert comprises a rigid plate and an adhesive material.

5. The golf club head of claim 1 , further comprising:

a region on the upper surface of the sole portion, along the entirety of which the interior sole line is below the trailing-edge sole line, wherein at least a portion of the flattened V-shape corresponds with at least a portion of the region.

6. The golf club head of claim 5 , wherein the flattened V-shape, in its entirety, corresponds with the region.

7. The golf club head of claim 6 , wherein the interior sole line generally follows the contour of the outer periphery of the lower surface of the sole portion along the entirety of the region.

8. The golf club head of claim 1 , wherein the golf club head is an iron-type golf club head.

9. An iron-type golf club head comprising:

a striking wall having a front surface and a rear surface;

a heel portion and an opposing toe portion;

a top portion extending from the heel portion to the toe portion;

a sole portion opposite the top portion and extending from the heel portion to the toe portion, the sole portion including a forward end, a rearward end, an upper surface, and a lower surface having an outer periphery, the outer periphery having a contour, the intersection of the upper surface of the sole portion and the rear surface of the striking wall defining an interior sole line that generally follows the contour of the outer periphery of the lower surface of the sole portion when viewed in rear elevation, the intersection of the upper surface of the sole portion and the rearward end of the sole portion defining a trailing-edge sole line;

a region on the upper surface of the sole portion, along the entirety of which the interior sole line is below the trailing-edge sole line;

an insert coupled to the rear surface of the striking wall, the insert including a rigid plate and an adhesive material,

wherein:

at least a portion of the trailing-edge sole follows a flattened V-shaped path when viewed in rear elevation;

at least a portion of the flattened V-shape corresponds with the region; and

in an imaginary vertical plane substantially perpendicular to the front surface of the striking wall, the interior sole line is below the trailing-edge sole line and the upper surface of the sole portion tapers from the trailing-edge sole line to the interior sole line.

10. A golf club head comprising:

a striking wall having a front surface and a rear surface;

a heel portion and an opposing toe portion;

a hosel portion proximate the heel portion for attaching the golf club head to a shaft;

a top portion extending from the heel portion to the toe portion;

a sole portion opposite the top portion and extending rearwardly from the rear surface of the striking wall from the heel portion to the toe portion, the sole portion having a forward end, a rearward end, an upper surface, and a lower surface, the intersection of the upper surface of the sole portion and the rear surface of the striking wall defining an interior sole line, the intersection of the upper surface of the sole portion and the rearward end of the sole portion defining a trailing-edge sole line; and

an outer periphery including portions delimited by the heel portion, the toe portion, the top portion, and the sole portion, the portions of the outer periphery having contours,

wherein:

the upper surface of the sole portion comprises a region configured such that, along the entirety of the region, the interior sole line is disposed below the trailing-edge sole line when the golf club head is oriented in an address position;

in a first imaginary vertical plane perpendicular to the front surface of the striking wall and passing through the region, the upper surface of the sole portion comprises a first difference in height between the interior sole line and the trailing-edge sole line when the golf club head is oriented in the address position;

in a second imaginary vertical plane perpendicular to the front surface of the striking wall and passing through the region, the upper surface of the sole portion comprises a second difference in height between the interior sole line and the trailing-edge sole line when the golf club head is oriented in the address position, the second difference in height not equal to the first difference in height; and

in a third imaginary vertical plane perpendicular to the front surface of the striking wall and passing through the region, the rearward end of the sole portion is rearwardly convex in its entirety and the upper surface tapers from the trailing-edge sole line to the interior sole line when the golf club head is in the address position.

11. The golf club head of claim 10 , wherein at least one of the interior sole line and the trailing-edge sole line generally follows the contour of the portion of the outer periphery delimited by the sole portion along the entirety of the region when view in rear elevation.

12. The golf club head of claim 11 , wherein only one of the interior sole line and the trailing-edge sole line generally follows the contour of the portion of the outer periphery delimited by the sole portion along the entirety of the region when viewed in rear elevation.

13. The golf club head of claim 11 , wherein only one of the interior sole line and the trailing-edge sole line generally follows the contour of the portion of the outer periphery delimited by the sole portion along the entirety of the sole portion.

14. The golf club head of claim 10 , wherein at least one of the interior sole line and the trailing-edge sole line generally follows the contour of the portion of the outer periphery delimited by the sole portion along the entirety of the sole portion when viewed in rear elevation.

15. The golf club head of claim 10 , further comprising an insert coupled to the rear surface of the golf club head.

16. The golf club head of claim 15 , wherein the insert comprises a rigid plate and an adhesive material.

17. The golf club head of claim 10 , further comprising a variation between the first difference in height and the second difference in height, the variation being greater than or equal to 0.2 in.

18. The golf club head of claim 17 , further comprising:

a face center of the front surface; and a heel portion and an opposing toe portion including a toe-most point,

wherein the region further comprises a heelward boundary and a toeward boundary, each located a distance of R*D from the face center, wherein D corresponds to the distance from the face center to the toe-most point, and R is a coefficient less than or equal to 0.54, the distance D measured parallel to the front surface and the ground plane.

19. The golf club head of claim 18 , wherein R is less than or equal to 0.49.

20. The golf club head of claim 17 , wherein the variation between the first difference in height and the second difference in height is greater than or equal to 0.25 in.

21. The golf club head of claim 10 , wherein the golf club head is an iron-type golf club head.