Golf club head
View Patent ↗A hollow golf club head comprises a face portion having a front face defining a clubface and a rear face facing the hollow. The face portion is provided in the rear face with a central protrusion and a plurality of radial protrusions extending radially from the central protrusion towards the peripheral edge of the face portion. The radial protrusions include at least one variable-width radial protrusion having a variable width increasing towards the peripheral edge from the radially inside. Preferably, a variable-width radial protrusion extending towards the crown portion, and a variable-width radial protrusion extending towards the sole portion of the club head are included.
1. A hollow golf club head comprising a face portion having a front face defining a clubface and a rear face facing the hollow, the face portion being provided in the rear face with a central protrusion and a plurality of radial protrusions extending radially from the central protrusion towards a peripheral edge of the face portion, whereby, between the radial protrusions, resultant reduced-thickness parts extending radially from the central protrusion towards the peripheral edge of the face portion are formed, wherein
the radial protrusions include at least one variable-width radial protrusion having a width increasing towards the peripheral edge from the central protrusion,
the central protrusion comprises a main part having a substantially constant thickness of from 2.5 to 4.0 mm, and a thickness-transitional part surrounding the main part,
the radial protrusions have a thickness less than the thickness of the main part,
the reduced-thickness parts have a minimum thickness of 1.6 to 3.0 mm, and
the thickness-transitional part has a thickness decreasing towards the peripheral edge so as to merge with the radial protrusions.
2. The hollow golf club head according to claim 1 , wherein the minimum width of the variable-width radial protrusion occurs near or at the radial inner end thereof, and
the ratio of the maximum width to the minimum width of the variable-width radial protrusion is in a range of 1.1 to 5.0.
3. The hollow golf club head according to claim 1 , wherein
at least one of the reduced-thickness parts which is adjacent to said at least one variable-width radial protrusion has a substantially constant width.
4. The hollow golf club head according to claim 1 , wherein the increasing of the width of the variable-width radial protrusion is continuous.
5. The hollow golf club head according to claim 1 , wherein
said at least one variable-width radial protrusion includes two variable-width radial protrusions which extend towards a crown and a sole of the club head.
6. The hollow golf club head according to claim 5 , wherein
a vertical line passing through the sweet spot of the clubface is included within the widths of said two variable-width radial protrusions.
7. The hollow golf club head according to claim 1 , wherein
said at least one variable-width radial protrusion includes two variable-width radial protrusions which extend towards a toe and a heel of the club head.