Iron-type golf club head
Disclosed herein is an iron-type golf club head that comprises a strike plate, an enclosed internal cavity, and a rear aperture formed in a rear wall. The iron-type golf club head also comprises a stiffening plug, within the internal cavity and compressed between the back surface of the strike plate and the rear wall. The stiffening plug is insertable, through a rear aperture, into the internal cavity. The iron-type golf club head further comprises a rear fascia covering the rear aperture and at least a portion of the rear wall. A characteristic time (CT) at a geometric center of the strike face is at least 250 microseconds. A maximum thickness of the strike plate, at the strike face, is less than 3.5 millimeters, inclusive. The strike plate, excluding grooves, has a minimum thickness between 1.1 millimeters and 2.2 millimeters.
1 . An iron-type golf club head, comprising:
a body, comprising a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, and a rear portion, wherein the rear portion comprises a rear opening, the rear opening having a total area of at least 400 square millimeters (mm 2 ), and wherein the front portion comprises a strike face and a back surface opposite the strike face;
a rear fascia, coupled to the rear portion of the body and covering the rear opening and at least partially enclosing an internal cavity; and
a stiffening material positioned within the internal cavity and in contact with the back surface of the front portion and a forward-facing surface of the rear portion, wherein the stiffening material is insertable, through the rear opening, into the internal cavity before the rear fascia is coupled to the rear portion of the body;
wherein a characteristic time (CT) at a geometric center of the strike face is at least 250 microseconds;
wherein a maximum thickness of the front portion, at the strike face, is less than or equal to 3.5 mm;
wherein the front portion, at the strike face, excluding grooves, has a minimum thickness between, and inclusive of, 1.1 mm and 2.2 mm;
wherein the rear fascia is made of a material having a density between, and inclusive of, 0.9 grams/cubic-centimeter (g/cc) and 5 g/cc;
wherein the iron-type golf club head has an external head volume between, and inclusive of, 15 cc and 70 cc, and the internal cavity has a cavity volume between, and inclusive of, 5 cc and 30 cc;
wherein the stiffening material occupies less than 25% of the back surface of the front portion along an x-axis, and the stiffening material has a surface area of at least 50 mm 2 ; and
wherein the stiffening material comprises a polymeric material having a density of no more than 1.75 g/cc.
2 . The iron-type golf club head according to claim 1 , wherein at least a portion of the rear opening extends from a first region of the rear portion, proximate the sole portion, to a second region of the rear portion, proximate the top-line portion.
3 . The iron-type golf club head according to claim 2 , wherein the second region is proximate to an underside surface of the top-line portion.
4 . The iron-type golf club head according to claim 2 , wherein a face thickness of the front portion, at a location corresponding with the first region, is greater than a face thickness of the front portion, at a location corresponding with the second region.
5 . The iron-type golf club head according to claim 1 , wherein the stiffening material has a hardness of at least 10 Shore A and no more than 40 Shore D.
6 . The iron-type golf club head according to claim 5 , further comprising at least one weight element, comprising tungsten, at least partially located within the internal cavity.
7 . The iron-type golf club head according to claim 6 , wherein the stiffening material has a mass of less than 5 g.
8 . The iron-type golf club head according to claim 7 , wherein the hardness of the stiffening material is at least 5.95 Shore D and the density of the stiffening material is at least 0.95 g/cc.
9 . The iron-type golf club head according to claim 8 , wherein the stiffening material has a face contact surface in contact with the back surface of the front portion, and wherein the face contact surface is circular.
10 . The iron-type golf club head according to claim 9 , wherein the stiffening material has a rear portion contact surface in contact with the rear portion, and wherein the rear portion contact surface is circular.
11 . The iron-type golf club head according to claim 8 , wherein the stiffening material comprises a tapered polymeric plug comprising a tapering sidewall.
12 . The iron-type golf club head according to claim 5 , wherein the stiffening material contacts the back surface of the front portion at spaced-apart locations on the back surface of the front portion.
13 . The iron-type golf club head according to claim 12 , wherein a combined surface area of the back surface of the front portion contacted by the stiffening material is at least 100 mm 2 .
14 . The iron-type golf club head according to claim 13 , wherein the stiffening material contacts at least 5% (0.05) of a total surface area of the back surface of the front portion.
15 . The iron-type golf club head according to claim 5 , wherein the front portion further comprises a front opening, wherein the strike face comprises a strike plate joined to the front portion to cover the front opening, and wherein the strike plate comprises a sole wrap portion that defines a portion of the sole portion.
16 . The iron-type golf club head according to claim 15 , wherein a portion of the strike plate is welded to the sole portion.
17 . The iron-type golf club head according to claim 16 , wherein the strike plate comprises a forged steel and at least a portion of the sole portion comprises stainless steel.
18 . The iron-type golf club head according to claim 16 , wherein the strike plate has a varying thickness with a maximum thickness of less than 2 mm.
19 . The iron-type golf club head according to claim 16 , wherein the strike plate is formed of a strike plate material different than a material forming the rear portion of the body.
20 . The iron-type golf club head according to claim 16 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having an x-axis and a z-axis, and wherein the geometric center of the face contact surface is at least 10 mm away from the z-axis when measured along the x-axis.
21 . The iron-type golf club head according to claim 16 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having a x-axis and a z-axis, and wherein the geometric center of the face contact surface is located toward the toe portion.
22 . The iron-type golf club head according to claim 16 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having a x-axis and a z-axis, and wherein the geometric center of the face contact surface has a positive x-axis coordinate.
23 . An iron-type golf club head, comprising:
a body, comprising a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, and a rear portion, wherein the rear portion comprises a rear opening, the rear opening having a total area of at least 400 square millimeters (mm 2 ), and wherein the front portion comprises a strike face and a back surface opposite the strike face;
a rear fascia, coupled to the rear portion of the body and covering the rear opening and at least partially enclosing an internal cavity; and
a stiffening material positioned within the internal cavity and in contact with the back surface of the front portion and a forward-facing surface of the rear portion, wherein the stiffening material is insertable, through the rear opening, into the internal cavity before the rear fascia is coupled to the rear portion of the body;
wherein a characteristic time (CT) at a geometric center of the strike face is at least 250 microseconds;
wherein a maximum thickness of the front portion, at the strike face, is less than or equal to 3.5 mm;
wherein the front portion, at the strike face, excluding grooves, has a minimum thickness between, and inclusive of, 1.1 mm and 2.2 mm;
wherein the rear fascia is made of a material having a density between, and inclusive of, 0.9 grams/cubic-centimeter (g/cc) and 5 g/cc;
wherein the iron-type golf club head has an external head volume between, and inclusive of, 15 cc and 70 cc, and the internal cavity has a cavity volume between, and inclusive of, 5 cc and 30 cc;
wherein the stiffening material occupies less than 25% of the back surface of the front portion along the x-axis;
wherein the front portion further comprises a front opening;
wherein the strike face comprises a strike plate joined to the front portion to cover the front opening;
wherein the strike plate comprises a sole wrap portion that defines a portion of the sole portion;
wherein a portion of the strike plate is welded to the sole portion; and
wherein at least a portion of the rear opening extends from a first region of the rear portion, proximate the sole, to a second region of the rear portion, proximate the top-line portion.
24 . The iron-type golf club head according to claim 23 , wherein the stiffening material comprises a polymeric material having a hardness of at least 10 Shore A, and a density of no more than 1.75 g/cc.
25 . The iron-type golf club head according to claim 24 , further comprising at least one weight element, comprising tungsten, at least partially located within the internal cavity, wherein the hardness of the stiffening material is no more than 40 Shore D and a mass of the stiffening material is less than 5 grams.
26 . The iron-type golf club head according to claim 25 , wherein the strike plate is formed of a strike plate material different than a material forming the rear portion of the body.
27 . The iron-type golf club head according to claim 26 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having an x-axis and a z-axis, and wherein the geometric center of the face contact surface is at least 10 mm away from the z-axis when measured along the x-axis.
28 . The iron-type golf club head according to claim 26 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having a x-axis and a z-axis, and wherein the geometric center of the face contact surface is located toward the toe portion.
29 . The iron-type golf club head according to claim 26 , wherein the stiffening material has a face contact surface in contact with the back surface of the strike plate, wherein the face contact surface has a geometric center that is offset from an origin of a club head origin coordinate system having a x-axis and a z-axis, and wherein the geometric center of the face contact surface has a positive x-axis coordinate.
30 . The iron-type golf club head according to claim 26 , further comprising at least one weight element, comprising tungsten, at least partially located within the internal cavity.
31 . An iron-type golf club head, comprising:
a body, comprising a heel portion, a sole portion, a toe portion, a top-line portion, a front portion, and a rear portion, wherein the rear portion comprises a rear opening, the rear opening having a total area of at least 400 square millimeters (mm 2 ), and wherein the front portion comprises a strike face and a back surface opposite the strike face;
a rear fascia, coupled to the rear portion of the body and covering the rear opening and at least partially enclosing an internal cavity; and
a stiffening material positioned within the internal cavity and in contact with the back surface of the front portion and a forward-facing surface of the rear portion, wherein the stiffening material is insertable, through the rear opening, into the internal cavity before the rear fascia is coupled to the rear portion of the body;
wherein a characteristic time (CT) at a geometric center of the strike face is at least 250 microseconds;
wherein a maximum thickness of the front portion, at the strike face, is less than or equal to 3.5 mm;
wherein the front portion, at the strike face, excluding grooves, has a minimum thickness between, and inclusive of, 1.1 mm and 2.2 mm;
wherein the rear fascia is made of a material having a density between, and inclusive of, 0.9 grams/cubic-centimeter (g/cc) and 5 g/cc;
wherein the iron-type golf club head has an external head volume between, and inclusive of, 15 cc and 70 cc, and the internal cavity has a cavity volume between, and inclusive of, 5 cc and 30 cc;
wherein the front portion further comprises a front opening;
wherein the strike face comprises a strike plate joined to the front portion to cover the front opening;
wherein the strike plate comprises a sole wrap portion that defines a portion of the sole portion, and a portion of the strike plate is welded to the sole portion;
wherein the stiffening material contacts less than 25% of a total surface area of a back surface of the strike plate, and the stiffening material has a surface area of at least 50 mm 2 ; and
wherein the stiffening material comprises a polymeric material having a hardness of at least 10 Shore A and no more than 40 Shore D, and a density of no more than 1.75 g/cc.
32 . The iron-type golf club head according to claim 31 , wherein the stiffening material contacts at least 5% (0.05) of a total surface area of the back surface of the strike plate.
33 . The iron-type golf club head according to claim 32 , further comprising at least one weight element, comprising tungsten, at least partially located within the internal cavity.
34 . The iron-type golf club head according to claim 33 , wherein the stiffening material has a mass of less than 5 g and a density of the stiffening material is at least 0.95 g/cc.
35 . The iron-type golf club head according to claim 33 , wherein at least a portion of the rear opening extends from a first region of the rear portion, proximate the sole portion, to a second region of the rear portion, proximate the top-line portion.
36 . The iron-type golf club head according to claim 35 , wherein a face thickness of the front portion, at a location corresponding with the first region, is greater than a face thickness of the front portion, at a location corresponding with the second region.
37 . The iron-type golf club head according to claim 32 , wherein the stiffening material contacts the back surface of the strike plate at spaced-apart locations on the back surface of the strike plate.