Patent Grant
7934998
This application claims priority on Patent Application No. 2007-016694 filed in JAPAN on Jan. 26, 2007. The entire contents of this Japanese Patent Application are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
Performances desired for hollow golf club heads include hitting sound, resilience, moment of inertia, ease of setting, and the like. Hitting sound of the hollow golf club head is loud. With respect to the hollow golf club heads, improvement of hitting sound has been desired. Clear hitting sound with high frequency is apt to be preferred. In addition, the hollow golf club head has a large volume. Large heads may be difficult in setting. Ease of setting correlates with the extent of setting stability. The term extent of setting stability means the extent of stability of the head in addressing. The heads with inferior setting stability are not stable in addressing.
Proposals for improvement of the hitting sound have been made. Japanese Unexamined Patent Application Publication No. Hei 10-33724 discloses a head provided with a Y-shaped metal inside the head for improving the hitting sound. Japanese Unexamined Patent Application Publication No. 2002-126136 discloses a head provided with a linear protrusion inside the head for improving the hitting sound. Japanese Unexamined Patent Application Publication No. 2004-49559 discloses a head with a devised sole for improving the hitting sound. Japanese Unexamined Patent Application Publication No. 2004-49733 discloses a head with a devised thickness of the sole for improving the hitting sound. United States patent corresponding to Japanese Unexamined Patent Application Publication No. 2002-126136 is U.S. Pat. No. 6,645,087. United States patent corresponding to Japanese Unexamined Patent Application Publication No. 2004-49733 is U.S. Pat. No. 7,160,205.
In the prior art described in the foregoing, the performances other than the hitting sound are not necessarily satisfactory. Furthermore, the head described in Japanese Unexamined Patent Application Publication No. Hei 10-33724 necessitates a large weight for the Y-shaped metal, whereby design freedom of the head is significantly reduced. In addition, the Y-shaped metal may be detached due to impact in hitting.
The present inventor found a novel head which can improve a variety of performances of the hollow head in addition to the improvement of the hitting sound. An object of the present invention is to provide a golf club head enabling improvement of the hitting sound, and also enabling a variety of other performances to be improved.
The golf club head according to the present invention has a face member, a crown member, a sole member and a recessed part. This recessed part is provided around the sole member. The recessed part has a maximum height Hm of equal to or greater than 10 mm. The projected area S1 of the sole member projected on the reference plane accounts for 40% or more and 65% or less of the projected area S2 of the crown member projected on the reference plane. This golf club head is hollow.
Preferably, the maximum angle θm formed between the margin of the recessed part and the sole edge in proximity thereto is equal to or greater than 45 degrees.
Preferably, the curvature radius of the sole face in a toe-heel direction is 9.0 cm or greater and 11.5 cm or less.
Preferably, the head volume is 400 cc or more and 500 cc or less.
According to the present invention, a hollow golf club head that is favorable in hitting sound with high performances can be obtained.
Hereinafter, the present invention will be explained in detail by way of preferred embodiments with appropriate reference to the accompanying drawings.
Head 2 has face member 4, crown member 6, sole member 8, recessed part 10 and hosel part 12. The external surface of the face member 4 corresponds to face surface 14. The external surface of the crown member 6 corresponds to crown face 16. The crown face 16 smoothly continues. The external surface of the sole member 8 corresponds to sole face 18. The hosel part 12 has shaft hole 20. As shown in
Furthermore, the head 2 has a side member 22. The external surface of the side member 22 corresponds to side face 24. The side member 22 is positioned between the crown member 6 and the sole member 8. It is acceptable that there exists no side member 22.
The recessed part 10 is provided around the sole member 8. The recessed part 10 is provided between the sole member 8 and the side member 22. The recessed part 10 is in proximity to or adjacent to the sole member 8. The recessed part 10 is adjacent to the sole face 18. The external surface of the recessed part 10 continues to the sole face 18.
At least a part of the sole face 18 can be in contact with the reference plane in the reference state described below. The sole face 18 is a face which continues almost smoothly. However, in the present invention, the level difference of less than 5 mm may not define the external margin (sole edge) of the sole face 18. The external side with the level difference of less than 5 mm is also included in the sole face 18. Grooves or recessed parts (logo and the like) having a height or depth of less than 5 mm can be also included in the sole face 18. When the external margin of the sole face 18 at the part adjacent to the recessed part 10 is indefinite, margin F1 of the recessed part 10 (described later) can correspond to the sole edge.
The recessed part 10 is provided at a part which can be generally referred to as sole member and/or side member. However, in the present invention, the sole member 8 is distinguished from the recessed part 10. Still further, the recessed part 10 is distinguished from the side member 22.
In the present invention, the reference state of the head is defined. This reference state is a state in which the head is placed on horizontal plane V1 in accordance with predetermined lie angle and real loft angle. The predetermined lie angle and the real loft angle are, for example, values provided in product catalog.
In the present invention, straight line L1, X axis, Y axis and Z axis are defined. The straight line L1 (not shown in the Figure) is a perpendicular line drawn from the center of gravity of the head to the face surface 14. The straight line L1 passes the center of gravity of the head, and the sweet spot. The X axis is a projected image generated by projecting the straight line L1 onto the horizontal plane V1. This projection is oriented along a perpendicular direction with respect to the horizontal plane V1. The Y axis is parallel to the horizontal plane V1, and is perpendicular to the X axis. The Z axis is perpendicular to the X axis, and is perpendicular to the Y axis. In
The margin F1 of the recessed part 10 is a boundary of the recessed part 10 and other part. The margin F1 of the recessed part 10 is defined as follows. A cross section of the head on a plane PL1 that is parallel to the X axis and the Z axis is envisioned. This plane PL1 can be established at any position along the Y axial direction.
In
When the maximum height Hm is great, the area of the sole member 8 is likely to be small. The sole member 8 vibrates upon impact. The number of vibration of the sole member 8 having a small area is great. Due to the great number of vibration, high hitting sound is likely to be generated. The high hitting sound is apt to be preferred by golf players. When the maximum height Hm is great, the surface area S3 of the external surface of the recessed part 10 is likely to be large. Upon hitting, stress is likely to be concentrated to the recessed part 10. By increasing the surface area S3, the stress concentration to the recessed part 10 can be moderated. Such moderation can contribute to improvement of durability of the head. In these respects, the maximum height Hm is preferably equal to or greater than 10 mm, more preferably equal to or greater than 12 mm, and particularly preferably equal to or greater than 15 mm. Because of limitation of the head size, the maximum height Hm is preferably equal to or less than 40 mm, more preferably equal to or less than 30 mm, and still more preferably equal to or less than 25 mm.
In light of improving the effect achieved by the recessed part 10, the surface area S3 of the recessed part 10 is preferably equal to or greater than 5 cm2, and more preferably equal to or greater than 10 cm2. In light of prevention of the projected area S1 of the sole member 8 from becoming too small, the surface area S3 of the recessed part 10 is preferably equal to or less than 50 cm2. When there are two or more recessed parts 10, the surface area S3 falls under total surface area of the two or more recessed parts 10.
In the present invention, the projected area S1 of the sole member 8, and the projected area S2 of the crown member 6 are defined. The projected area S1 is a projected area of the sole face 18 projected to the reference plane on the head in the reference state described above. The direction of this projection is a perpendicular direction with respect to the reference plane. The projected area S2 is a projected area of the crown face 16 projected to the reference plane on the head in the reference state described above. The direction of this projection is perpendicular with respect to the reference plane.
The projected area S1 of the sole member 8 is smaller than the projected area S2 of the crown member 6. Small projected area S1 is likely to result in high frequency of the hitting sound. Furthermore, when the projected area S1 is narrow, increase in the head weight is diminished even though the thickness of the sole member 8 is increased. Therefore, when the projected area S1 is small, thickness of the sole member 8 can be easily increased. The thick sole member 8 further increased the number of vibration of the sole member 8.
In light of improvement of the setting stability, the projected area S1 of the sole member 8 is preferably equal to or greater than 40%, more preferably equal to or greater than 41%, still more preferably equal to or greater than 45%, and yet further preferably equal to or greater than 53% of the projected area S2 of the crown member 6. In light of attaining a high hitting sound, the projected area S1 of the sole member 8 is preferably equal to or less than 65%, more preferably equal to or less than 62%, and still more preferably equal to or less than 60% of the projected area S2 of the crown member 6.
When the projected area S2 of the crown member 6 is too small, the head volume is likely to be decreased. For increasing the head volume while keeping the projected area S2 small, it would be necessary to increase the height of the head. Typical example in which the head height is elevated may include deep face head, generally referred to. When the head height is increased too much, the center of gravity of the head becomes excessively high. When the center of gravity of the head is elevated, back spin rate is likely to be increased due to so called gear effect. When the center of gravity of the head is elevated, the flight distance is likely to be decreased. In this respect, the projected area S2 is preferably equal to or greater than 80 cm2, and more preferably equal to or greater than 90 cm2. When the projected area S2 is too great, the player may feel discomfort in addressing. In addition there is a restriction in regulation for enlargement of the crown member 6. The rule directed by Japan Golf Association defines that the length from the heel to the toe of the head must be equal to or less than 5 inches. Moreover, this rule defines that the length from the heel to the toe of the head must be longer than the length of from the face to the back. In light of suppression of the discomfort in addressing, and obeying of the rules, the projected area S2 is preferably equal to or less than 150 cm2, and more preferably equal to or less than 130 cm2.
In light of improvement of the setting stability, the projected area S1 of the sole member 8 is preferably equal to or greater than 40 cm2, more preferably equal to or greater than 45 cm2, and still more preferably equal to or greater than 50 cm2. In light of attaining a high hitting sound, the projected area S1 is preferably equal to or less than 75 cm2, more preferably equal to or less than 65 cm2, and still more preferably equal to or less than 60 cm2.
When the recessed part 10 is replaced by a flat shape, the surface area of the replaced part becomes smaller the recessed part 10. To the contrary, through replacing the flat part by the recessed part 10, the surface area is increased. The replacement of the flat shape by the recessed part 10 leads to increase in the weight of the replaced part. This increase in the weight is apt to result in increase in the moment of inertia of the head.
In
In
In
In
The angle θ1 is determined by the cross section with respect to the plane PL1, or the cross section with respect to the plane PL2. The plane PL1 is as described above. The plane PL2 is a plane that is parallel to the Y axis and Z axis. The angle θ1 can be determined at any position along the X axial direction and the Y axial direction. In the cross section with respect to the plane PL1 or the plane PL2, a tangent line L3 at a point 3 mm away from the margin F1 to the side of the recessed part 10, and a tangent line L4 at a point 3 mm away from the sole edge E1 to the side of the sole member 8 can be established. The angle θ1 is an angle formed between the tangent line L3 and the tangent line L4. The angle θ1 can vary depending on the position of the X axial direction or the Y axial direction. The maximum angle θm is a maximum value among all angles θ1. In the embodiment shown in
When the maximum angle θm is small, boundary of the sole member 8 and the recessed part 10 gets closer to flat. Therefore, the sole member 8 is likely to be deformed, while the number of vibration of the sole member 8 is likely to be decreased. In light of attaining of a high hitting sound, the maximum angle θm is preferably equal to or greater than 45 degrees, more preferably equal to or greater than 50 degrees, still more preferably equal to or greater than 55 degrees, and yet more preferably equal to or greater than 65 degrees. In light of moderation of the stress concentration to the margin F1 or the sole edge E1, the maximum angle θm is preferably equal to or less than 120 degrees, more preferably equal to or less than 90 degrees, and still more preferably equal to or less than 85 degrees.
In light of improvement of the setting stability, the curvature radius R1 of the sole face 18 is preferably equal to or greater than 9.0 cm. In light of increase in the number of vibration of the sole member 8, and attaining of a high hitting sound, the curvature radius R1 is preferably equal to or less than 11.5 mm. This curvature radius R1 a curvature radius in a toe-heel direction. This curvature radius R1 is measured in the cross section with respect to the aforementioned plane PL2.
In the head in the aforementioned reference state, the profile line in contact with the horizontal plane V1 preferably has a straight line L5 which is parallel to the horizontal plane V1, among profile lines on the sole face 18 with respect to the aforementioned plane PL1. Accordingly, the setting stability of the head 2 is improved. In light of improvement of the setting stability, the length of the straight line L5 accounts for preferably 50% or more of the entire length of the profile line of the sole face 18 including this straight line L5.
In the head in the aforementioned reference state, the coordinate on the Z axis, i.e., Z coordinate is envisaged. The value of this Z coordinate is greater as it is positioned upper side. This Z coordinate is represented by a plus value on the upper side. The Z coordinate at a point Pt on the most toe side on the sole face 18 is defined as ZT (mm), and the Z coordinate at a point Pc on the undermost side on the sole face 18 is defined as ZC (mm). In addition, the Z coordinate at a point Ph on the most heel side on the sole face 18 is defined as ZH (mm). In light of preventing the sole member 8 from deformation, and attaining of a high hitting sound, the value [ZT−ZC] is preferably equal to or greater than 5 mm, more preferably equal to or greater than 8 mm, and still more preferably equal to or greater than 10 mm. In light of lowering of the center of gravity of the head to improve the performances in hitting of the ball, the value [ZT−ZC] is preferably equal to or less than 20 mm, more preferably equal to or less than 18 mm, and still more preferably equal to or less than 15 mm. In light of preventing the sole member 8 from deformation, and attaining of a high hitting sound, the value [ZH−ZC] is preferably equal to or greater than 5 mm, more preferably equal to or greater than 8 mm, and still more preferably equal to or greater than 10 mm. In light of lowering of the center of gravity of the head to improve the performances in hitting of the ball, the value [ZH−ZC] is preferably equal to or less than 20 mm, more preferably equal to or less than 18 mm, and still more preferably equal to or less than 15 mm.
In light of attaining a more favorable hitting sound, it is preferred that the Z coordinate of the line L6 connecting the point Pt and the point Pc drawn on the sole face 18 at a minimum distance gradually increased from the point Pc to the point Pt. In light of attaining a more favorable hitting sound, it is preferred that the Z coordinate of the line L7 connecting the point Ph and the point Pc drawn on the sole face 18 at a minimum distance gradually increased from the point Pc to the point Ph. When the Z coordinate of the line L6 or line L7 is altered stepwise or abruptly, the hitting sound is likely to be deteriorated because almost plane part may be readily generated on the sole face 18. When there exist multiple points Pc, it is preferred that the Z coordinate of the line L6 or line L7 gradually increases as described above with respect to at least one point Pc. More preferably, the Z coordinates of the lines L6 or lines L7 may gradually increase as described above with respect to all the points Pc.
In light of improvement of the resilience performance accompanied by ease in adjusting the timing of the swing, the head weight is preferably equal to or greater than 180 g. When the head is too heavy, the club cannot be swung through, whereby the flight distance or the directionality of the hit ball is likely to be inferior. In this respect, the head weight is preferably equal to or less than 210 g.
A groove may be also provided on the sole member. The groove can increase the rigidity around the groove, and the frequency of the sole vibration can be increased. The shape of the groove is not particularly limited. In light of facilitating the manufacture, the width of the groove is preferably equal to or greater than 0.5 mm, more preferably equal to or greater than 1 mm, and particularly preferably equal to or greater than 2 mm. The width of the groove being too great results in a state approximate to the state in which no groove is provided, whereby the effect of the groove may be hardly achieved. In this respect, the width of the groove is preferably equal to or less than 10 mm, more preferably equal to or less than 8 mm, and particularly preferably equal to or less than 5 mm. The depth of the groove being too small results in a state approximate to the state in which no groove is provided, whereby the effect of the groove may be hardly achieved. In this respect, the depth of the groove is preferably equal to or greater than 0.5 mm, and more preferably equal to or greater than 1 mm. When the groove is too deep, rigidity of the groove part is deteriorated, whereby the number of vibration of the sole member 8 may be decreased. Additionally, too deep groove may lead to increase in probability of generation of a crack that begins at the groove. In these respects, the depth of the groove is preferably equal to or less than 5 mm, and more preferably equal to or less than 3 mm.
A rib may be provided inside of the sole member. The protrusion can increase the rigidity of the sole member, whereby high hitting sound is likely to be attained. In light of improvement of the hitting sound, the width of the rib is preferably equal to or greater than 0.5 mm, and more preferably equal to or greater than 0.8 mm. In light of suppression of increase in the weight of the sole member, the width of the rib is preferably equal to or less than 2 mm, and more preferably equal to or less than 1.5 mm. In light of improvement of the hitting sound, the height of the rib is preferably equal to or greater than 0.2 mm, and more preferably equal to or greater than 0.5 mm. In light of suppression of increase in weight of the sole member, the height of the rib is preferably equal to or less than 2 mm, and more preferably equal to or less than 1 mm.
The method of manufacturing the head is not limited. Examples of the method of manufacture include casting, forging, pressing and the like. The hollow head can be obtained by joining two or more members. For the joining, welding can be adopted. For example, a head obtained by welding of a face member and a head main body may be illustrated.
The thickness of each part of the head is not limited. In light of enhancement of the strength, the crown member has a thickness of preferably equal to or greater than 0.3 mm. In light of increase in size of the head with a limited head weight, the crown member has a thickness of preferably equal to or less than 1.2 mm. In light of enhancement of the strength, the side member has a thickness of preferably equal to or greater than 0.3 mm. In light of increase in size of the head with a limited head weight, the side member has a thickness of preferably equal to or less than 1.2 mm. In light of enhancement of the strength, and lowering of the center of gravity of the head, the sole member has a thickness of preferably equal to or greater than 0.8 mm. In light of increase in size of the head with a limited head weight, the sole member has a thickness of preferably equal to or less than 3.0 mm. In light of enhancement of the strength, the face member has a thickness of preferably equal to or greater than 2.5 mm. In light of increase in size of the head with a limited head weight, the face member has a thickness of preferably equal to or less than 4.0 mm. In light of enhancement of the strength, and increase in the moment of inertia of the head, the recessed part has a thickness of preferably equal to or greater than 0.3 mm, and more preferably equal to or greater than 0.8 mm. In light of increase in size of the head with a limited head weight, the recessed part has a thickness of equal to or less than 3.0 mm, and more preferably equal to or less than 1.2 mm.
The material of the head is not limited. Examples of the material of the head include metals, CFRP (carbon fiber reinforced plastics), and the like. As the metal, one or more of stainless steel, maraging steel, titanium, titanium alloy, magnesium alloys and amorphous alloys are preferred. As a part of the head, a weight member having a large specific gravity may be also used.
In light of improvement of the resilience coefficient, increase in the moment of inertia, and increase in the depth of the center of gravity, the head volume is preferably equal to or greater than 400 cc, more preferably equal to or greater than 420 cc, and still more preferably equal to or greater than 440 cc. In light of ease of setting, and ease in swinging, the head volume is preferably equal to or less than 500 cc, more preferably equal to or less than 480 cc, and still more preferably equal to or less than 460 cc.
Head 26 has face member 28, crown member 30, sole member 32, recessed parts 34, 35 and hosel part 36. The head 26 has two recessed parts 34, 35. The external surface of the face member 28 corresponds to face surface 38. The external surface of the crown member 30 corresponds to crown face 40. The crown face 40 smoothly continues. The external surface of the sole member 32 corresponds to sole face 42. The hosel part 36 has shaft hole 44. As shown in
Furthermore, the head 26 has a side member 46. The external surface of the side member 46 corresponds to side face 48. The side member 46 is positioned between the crown member 30 and the sole member 32. It is acceptable that there exists no side member 46.
The recessed part 34 is provided around the sole member 32. The recessed part 34 is provided between the sole member 32 and the side member 46. The recessed part 34 is in proximity to or adjacent to the sole member 32. The recessed part 34 is adjacent to the sole face 42. The external surface of the recessed part 34 continues to the sole face 42.
The recessed part 35 is provided around the sole member 32. The recessed part 35 is provided between the sole member 32 and the side member 46. The recessed part 35 is in proximity to or adjacent to the sole member 32. The recessed part 35 is adjacent to the sole face 42. The external surface of the recessed part 35 continues to the sole face 42. The recessed part 35 is provided on the side closer to the heel than the recessed part 34.
Hereinafter, advantages of the present invention will be explained by way of Examples, however, the present invention should not be construed as being limited based on the description of the Examples.
A face member was obtained by press molding of a plate material. The head main body was integrally molded by casting. The head main body includes a crown member, a sole member, a side member, a hosel part and a recessed part. The face member and the head main body were welded to obtain the head shown in from
The heads of Examples 2 to 5 and Comparative Example 3 were obtained in a similar manner to Example 1 except that the specifications were as shown in Table 1. Specifications and evaluation results of these examples are shown in the following Table 1.
The head of Example 6 was obtained in a similar manner to Example 1 except that the head shape was as shown in from
Head 50 of Comparative Example 1 is shown in from
The head of Comparative Example 2 was obtained in a similar manner to Comparative Example 1 except that the specifications were as shown in Table 1. Specifications and evaluation results of Comparative Example 2 are shown in the following Table 1.
Measurement of Lateral Moment of Inertia
The lateral moment of inertia was measured using MOMENT OF INERTIA MEASURING INSTRUMENT MODEL NO. 005-002 manufactured by INERTIA DYNAMICS INC. The lateral moment of inertia is a moment of inertia around an axis that passes the center of gravity of the head, and is parallel to the aforementioned Z axis. The measurement results are shown in the following Table 1.
Peak Frequency
A carbon shaft and a grip were attached to the head, whereby a golf club was produced. This golf club was mounted to a swing robot, and the golf balls were hit at a head speed of 40 m/s. Golf balls used were two-piece ball “SRIXON AD333” manufactured by SRI SPORTS LIMITED. The ball was teed, and hit. A microphone was placed at a position 30 cm away from the tee, at a position on the toe side of the head at impact. The recorded hitting sound was subjected to Fourier transformation with an FFT analyzer, and ⅓ octave band processing. The frequency of the highest sound pressure was determined as a peak frequency. The results of the measurement are shown in Table 1 below.
Sensuous Evaluation
Using a golf club to which each head was attached, ten golf players hit golf balls. Handicap of the ten golf players is in the range of 20 or lower. Comfort of the hitting sound was evaluated on a 5-point scale of from one to five. Higher score represents better evaluation. Average values rated by the ten golf players are shown in the following Table 1.
As shown in Table 1, Examples were more highly evaluated in comparison with Comparative Examples. Accordingly, advantages of the present invention are clearly indicated by these results of evaluation.
The present invention can be applied to every golf club head such as wood golf club heads, utility golf club heads, iron golf club heads, and the like.
The description hereinabove is merely for an illustrative example, and various modifications can be made in the scope not to depart from the principles of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-016694 | Jan 2007 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1541126 | Dunn | Jun 1925 | A |
| 3625518 | Solheim | Dec 1971 | A |
| 3976299 | Lawrence et al. | Aug 1976 | A |
| 4444392 | Duclos | Apr 1984 | A |
| 5203565 | Murray et al. | Apr 1993 | A |
| 5288079 | Katayama | Feb 1994 | A |
| 5301945 | Schmidt et al. | Apr 1994 | A |
| 5326105 | Fenton, Jr. | Jul 1994 | A |
| 5435558 | Iriarte | Jul 1995 | A |
| 5451056 | Manning | Sep 1995 | A |
| 5460376 | Schmidt et al. | Oct 1995 | A |
| 5467988 | Henwood | Nov 1995 | A |
| 5470068 | Schmidt et al. | Nov 1995 | A |
| 5470069 | Schmidt et al. | Nov 1995 | A |
| 5630766 | Granelli | May 1997 | A |
| 5697853 | Schmidt et al. | Dec 1997 | A |
| 6120389 | Kruse | Sep 2000 | A |
| 6332848 | Long et al. | Dec 2001 | B1 |
| 6645087 | Yabu | Nov 2003 | B2 |
| 6960141 | Noguchi et al. | Nov 2005 | B2 |
| 7160205 | Yamamoto | Jan 2007 | B2 |
| 7163468 | Gibbs et al. | Jan 2007 | B2 |
| 7166038 | Williams et al. | Jan 2007 | B2 |
| 7169060 | Stevens et al. | Jan 2007 | B2 |
| 7192364 | Long | Mar 2007 | B2 |
| 7278927 | Gibbs et al. | Oct 2007 | B2 |
| 7291075 | Williams et al. | Nov 2007 | B2 |
| 7306527 | Williams et al. | Dec 2007 | B2 |
| 7311613 | Stevens et al. | Dec 2007 | B2 |
| 7390269 | Williams et al. | Jun 2008 | B2 |
| 7407448 | Stevens et al. | Aug 2008 | B2 |
| 7419440 | Williams et al. | Sep 2008 | B2 |
| 7455598 | Williams et al. | Nov 2008 | B2 |
| 7476161 | Williams et al. | Jan 2009 | B2 |
| 7488261 | Cackett et al. | Feb 2009 | B2 |
| 7494424 | Williams et al. | Feb 2009 | B2 |
| 7559851 | Cackett et al. | Jul 2009 | B2 |
| 20060281581 | Yamamoto | Dec 2006 | A1 |
| Number | Date | Country |
|---|---|---|
| 10-33724 | Feb 1998 | JP |
| 2004-49559 | Feb 2004 | JP |
| 2006-297117 | Nov 2006 | JP |
| 2006-340846 | Dec 2006 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20080182681 A1 | Jul 2008 | US |
