GOLF-CLUB PROVIDED WITH A CLUB-HEAD HAVING SURFACES CONFIGURED TO BE COVERED BY AIR VORTEX FLOWS

Abstract

This invention provides a golf club with a club-head configured so as to decrease air resistance of the head by avoiding the air flows from retouching on the head surface. The club-head is provided with a ridge structure which contains a first ridge and a second ridge arranged at intervals in a downward direction of the air flows on at least the sole part of the head, wherein each of the ridges has the height of 0.2 mm to 3 mm and the breadth of 1 mm to 5 mm, the ridge structure being configured by plural ridges so as to displace the inclined angle of the ridges in a clockwise direction, resulting in generation of air vortex or whirls between the head surface and the surrounding air flows as shown in FIG. 2.

Claims

1. A golf-club comprising; a club-head including a face at which the club-head is arranged to collide in a first direction with a golf ball, a sole, and a ridge structure being on a surface of the sole, the ridge structure including a first ridge and a second ridge arranged at an interval, the first and second ridges extending in a second direction perpendicular to the first direction, the interval being larger than a width of the first ridge.

2. The golf-club according to claim 1, wherein at least part of the first and second ridges are extending in a radial direction, and the second ridge has an angle in a clockwise direction with respect to the first ridge.

3. The golf-club according to claim 1, wherein the first ridge and the second ridge make a substantially enclosed space.

4. The golf-club according to claim 1, wherein the ridge structure includes a U letter shape ridge on the surface of the sole, and the first and second ridges extend from the U letter shape ridge.

5. The golf-club according to claim 1, wherein the ridge structure is configured to be a concentric multiple polygon made of homothetic polygons 21, 22 and 23 and the bottom lines are faced parallel to the face surface of the head and wherein the multiple polygons are divided by lines 24 connecting from outer aspects to inner aspects.

6. The golf-club according to claim 1, wherein the ridge structure is configured to be concentric multiple circles on the surface 30 made of multiple circle ridges 31, 32 and 33 and divided by radically extending lines 34 from the center.

7. The golf-club according to claim 1, wherein the ridge structure is configured to be a wind mill made of multiple arrow fletchings 41a, 41b, 41c, 41d, and 41e radially arranged with their circumference edges partitioned by ridges.

8. The golf-club according to claim 1, wherein the ridge structure is configured to be almost N letter arrows of lighting made of closed spaces 51, 52 and 53 and arranged irregularly so as to displace the inclined angle of the ridges in a clockwise direction.

9. The golf-club according to claim 1, wherein the first ridge has a height of 0.2 mm to 3 mm and a breadth of 1 mm to 5 mm.

10. The golf-club according to claim 1, wherein the first and second ridges protrude perpendicularly with respect to the surface of the sole.

11. The golf-club according to claim 1, wherein the first and second ridge are linearly formed, and successively or intermittently formed

Description

THE SIMPLE EXPLANATION OF THE DRAWING

[0014] FIG. 1(a) is a head trajectory view of the club swing showing a relation between the bending moment and the twist moment of the shaft,

[0015] FIG. 1(b) is a explanation view showing a relation between the shaft line and the gravity operation line.

[0016] FIG. 1(c) is a sectional view showing a state of the surrounding air flow.

[0017] FIG. 2(a) is a plain view showing a crown side surface of the head.

[0018] FIG. 2(b) is a plain view showing a sole side surface of the head.

[0019] FIG. 2(c) is a side view of a side surface of the head showing a relation between air whirls generated on the surface and the surrounding air flows.

[0020] FIG. 3 is an explanation view showing a process for making air whirls on the surface.

[0021] FIG. 4 is a plain view of a second ridge structure provided with multiple polyhedrons on the sole surface according to the present invention.

[0022] FIG. 5 is a plain view of a third ridge structure provided with multiple circles on the sole surface according to the present invention.

[0023] FIG. 6 is a plain view of a fourth ridge structure provided with windmill shape on the sole surface according to the present invention.

[0024] FIG. 7 is a plain view of a fifth ridge structure provided with arrows of lighting shape on the sole surface according to the present invention.

THE PREFERRED EMBODIMENT

[0025] The bending moment and the twist moment generated on the shaft is generally caused by the head motion during swinging as shown in FIG. 1. [0026] (1) At the top position of the swing, the shaft tends to be bent in an opposite direction of the gravity by the head downward motion. [0027] (2) and (3) The bending motion generates by the action of swing power when the down swing begins. [0028] (4) At the middle of the down swing, a reaction force generates against the bending motion and a reverse whip of the shaft starts. [0029] (5) The reverse whip degree is increasing gradually and at the same time, the twist moment of the shaft begins to generate. [0030] (6) At the impact, the reverse whip is getting back, whereby the edge of the head begins to toe-in.

[0031] In order to decrease the twist moment, movement of the head gravity from toe to heel has been researched. According to the present invention, we realized to decrease the twist moment and the bending moment by the air flows surrounding the head.

[0032] In case of the right-handed, the left rotation swing together with the body movement causes a twist of the shaft, because the shaft A-B between the grip A and the head B has a angle of misfitting with the line between the grip A and the gravity G, so that the gravity force impinges on a part between the gravity G and the shaft edge E. The twist moment should be decreased by synergy effect of the movement of gravity and the decrease of the air resistance of the head.

[0033] From the swing trajectory, the air resistance generated during the process (1) to (6) is not supposed to be caused by the face part because the face takes a position square to the air flows just only for a short time and a short distance between before and after the impact, totally 10% of the all swing time and distance as shown in FIG. 2. The other swing time and distance give the centrifugal force longer and much more on the head. From the trajectory of the swing motion as shown in FIG. (a), the sole part is always and dominantly contacting with the surrounding air. In the light of the fact, decrease of the all air resistance of the head can be realized simply by decrease of the air resistance of the sole part. Of course, the air resistance together with the side parts and the crown part had better to be decreased. Because the bigger the air resistance, the bigger the resulting twist of the shaft and finally the bigger the bending moment and the twist moment. The moment on the shaft tends to be proportional to an area and a time contacting with the air. The decrease of the air resistance by the dominant sole part makes the total resistance smaller. Similarly, change of the air flows from the laminar flow to turbulence flow on the side parts and the crown part makes the total air resistance much smaller. According to the present invention, the golfer can swing it more smoothly and get 10 yards or 20 yards longer driving depending on 5% more head speed.

EXAMPLE 1

[0034] According to the present invention, a golf club comprises a wood club-head and a shaft wherein the club-head is provided with a crown surface 11, on which a pair of ridges 11a, 11b are extended from a toe side to a heel side and a pair of L letter ridges 11c,11c are positioned toward a back end side of the crown as shown in FIG. 2(a). On the other hand, a sole surface of the head is provided with a U letter ridge 12a extending from a face side to a back side, from which plural ridges 12b,12c are formed in a predetermined interval and extending radially to a circumference edge as shown in FIG. 2(b) The radial extending ridges displace the angle direction in the light of the head face direction changing during the swing. In this example, the ridge height is 0.7 mm and the breadth is 2.7 mm which are allowable to be adjusted in the above scope. According to the embodiment, the surrounding airs can smoothly flow without retouching to the head surface by intermediate air whirls between the surrounding air flows and the crown and sole surfaces as shown in FIG. 2(c).

[0035] According to the preferred embodiment, the outside surrounding air layer presses down upcoming air flows after crashing against the first ridge and then the pressed air flows cross over the first ridges into the space in front of the second ridges and crash again against the second ridges to generate back flows. These repeated actions makes air whirls between the surrounding air layer and the head surface, whereby the air resistance of the head can be decreased by avoiding the surrounding air from retouching on the club-head surface.

[0036] In the embodiment of the invention, the ridges may generally be formed as a linear ridge parallel to the face surface on the crown surface with the height of 0.2 mm to 3 mm and the breadth of 1 mm to 5 mm. According to the present invention, the ridge shape can not limited to the linear ones. It is important that the ridge shape should be configured to have a function to make air whirls between the space between the first and the second ridges by repeat of the action of the air flows crashing against the ridges to generate back flows. The height and intervals of the ridges may be adjusted so as to generate air whirls between the space between the first and the second ridges, which is not limited to the linear ones.