BAT GRIPPING STRUCTURE AND BAT STRUCTURE PROVIDED WITH SAME

Abstract

To provide a bat gripping structure that enables a batter to achieve a proper grip, a grip structure is provided in which the bat is in the “top” position during the take-back of batting, in order to accomplish the swing “to put the bat outwardly from inside” along a line of the bottom hand, a locking structure that enables a lower region (bottom grip) of the grip portion to be gripped at the grip portion of the bat under the palmar grip is employed to provide the grip structure effective to lock the palmar grip of the bottom hand, so that a proper swing to “put the bat out from inside” may be achieved and the angular velocity during the bat swinging is increased. Also, the bat structure is also provided in which by adding a weight ΔM (10˜100 gr) to the bat head H of the bat having the grip structure of the kind referred to above, the batting energy at the sweet spot is improved to enhance the impact having the maximum batting effect.

Claims

1. A bat grip structure which includes a bat head H, a bat barrel portion, a bat throat portion T, a bat grip portion G and a grip end E, characterized in that: 1) in the grip portion G extending from the grip end to the bat throat portion T, the grip portion has a sectional shape perpendicular to the longitudinal axis of the bat, which shape is represented by a generally oval shape suited for gripping with a palm, in which when the grip center Gc is moved to Gc1, the batting centroid Pc is adjustable to Pc1 while securing the palm grip of the bottom hand is secured, and in that 2) the grip end is inclined forwards at an angle within the range of 20 to 30 degrees relative to a plane perpendicular to the longitudinal axis of the bat, and has a lock structure capable of turning about the hand wrist of the bottom hand to urge towards a thumb side, and in that 3) the grip end bulges, laterally outwardly at least one side of an end inclined face over the generally oval section of the grip portion to form a Japanese OTAFUKU shaped bulge portion having a step portion between the grip end and the grip portion G for engaging with the little finger tip and/or the palm edge adjacent to the little finger third joint of the bottom hand in a manner to prevent the bottom hand edge from slipping out from the grp end during the swinging.

2. The bat structure as claimed in claim 1, in which the bat grip portion G is such that 1)′, when the palm of the bottom hand is in contact with a portion of the grip portion G ranging from the grip end to the bat throat portion T, the sectional shape perpendicular of the grip portion ranging from the palm of the bottom hand to the middle finger of the upper hand that lies perpendicular to the longitudinal axis of the bat is represented by a generally oval shape suited for gripping by the palm, and an inclined portion is formed in a direction upwardly of the bat over the middle finger of the upper grip to change at least the grip portion oval sectional shape to a circular sectional shape of the bat throat portion with a decreased cross sectional area to thereby form a double stepped grip; and in that with the grip center Gc moved to Gc1, one selection is possible from two positions, one is a half palmar grip position, where the forefinger and the thumb finger are released and the other is a finger grip position where the top hand on the inclined portion with a decreased cross sectional area is under a finger grip, while the bottom hand is secured, thereby adjusting the batting centroid from Pc to Pc1.

3. The bat grip structure as claimed in claim 1, in which in at least an intermediate portion of the semi-perimetric portion of the grip portion that is gripped by the palm of the bottom hand and the upper hand and in the vicinity thereof 3) an inclined portion for increasing the coefficient of friction of the grip is formed to thereby reinforce the palm grip.

4. A bat grip structure which includes a bat head H, a bat barrel portion, a bat throat portion T, a bat grip portion G and a grip end E, characterized by the provision of: 1) a gravitational center position changing structure for displaying the original position of a bat center of gravity C, which lies at the bat barrel portion B, in a batting centroid Pc direction by adding an additional weight ΔM to the bat head, the grip portion has a sectional shape perpendicular to the longitudinal axis of the bat, which shape is represented by a generally oval shape suited for gripping with a palm, in which when the grip center Gc is moved to Gc1, the batting centroid Pc is adjustable to Pc1 while securing the palm grip of the bottom hand is secured, and in that 2) the grip end is inclined forwards at an angle within the range of 20 to 30 relative to a plane perpendicular to the longitudinal axis of the bat, and has a lock structure capable of turning about the hand wrist of the bottom hand to urge towards a thumb side and 3) the grip end bulges, laterally outwardly at least one side of an end inclined face over the generally oval section of the grip portion to form a Japanese OTAFUKU shaped bulge portion having a step portion between the grip end and the grip portion G for engaging with the little finger tip and/or the palm edge adjacent to the little finger third joint of the bottom hand in a manner to prevent the bottom hand edge from slipping out from the grp end during the swinging, and a function of transmitting the batting centroid Pc˜Pc1 where the maximum moment ω imposed on the center of gravity that is obtained at the maximum angular velocity ω brought about by the grip structure.

5. The bat structure as claimed in claim 4, characterized in that the bat grip portion G is such that 1)′, when the palm of the bottom hand is in contact with a portion of the grip portion G ranging from the grip end to the bat throat portion T, the sectional shape perpendicular of the grip portion ranging from the palm of the bottom hand to the middle finger of the upper hand that lies perpendicular to the longitudinal axis of the bat is represented by a generally oval shape suited for gripping by the palm, and an inclined portion is formed in a direction upwardly of the bat over the middle finger of the upper grip to change at least the grip portion oval sectional shape to a circular sectional shape of the bat throat portion with a cross sectional area to thereby form a double stepped grip; and in that with the grip center Gc moved to Gc1, one selection is possible from two positions, one is a half palmar grip position, where the forefinger and the thumb finger are released and the other is a finger grip position where the top hand on the inclined portion with a decreased cross sectional area is under a finger grip, while the bottom hand is secured, thereby adjusting the batting centroid from Pc to Pc1.

6. The bat structure as defined in claim 4 or 5, characterized in that in an at least intermediate portion of a semi-perimetric portion of the grip portion wrapped by the palm of the bottom hand and the upper hand and in the vicinity thereof, 4) the region for increasing the coefficient of friction of the grip is formed to reinforce the palmar grip

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a perspective view showing a grip structure designed in accordance with a preferred embodiment of the present invention, which grip structure includes a friction increasing area defined at a portion of the bat which contacts a palmar surface of the bottom hand in a grip area of an oval sectional shape, with a grip end surface lying at an angle within the range of 20 to 30 degrees relative to a plane perpendicular to the longitudinal axis of the bat, and a lock structure defined at the boundary between the grip area and the grip end;

[0023] FIG. 2 is a perspective view showing the grip area being gripped, in which the lock structure is represented by a Japanese Otafuku shape (virtually trochoidal shape) that form a bulged portion swelling outwardly along a grip end inclined surface, which serves to avoid drop-out of the tip of little finger and the third joint of little finger and also a palmar end situated therebelow;

[0024] FIG. 3A is a diagram showing the basic shape, as viewed from diagonally rearward, in which three right angles are depicted at top;

[0025] FIG. 3B is a diagram showing the basic shape, as viewed from rearward, in which three right angles are depicted at top;

[0026] FIGS. 4A-4D are explanatory diagrams showing the sequence of batting in which the distance between the bat and a batter's shoulder and also the right angular relationship between the bottom hand and the bat do not change from the condition shown in FIGS. 3A and 3B;

[0027] FIGS. 5A-5C illustrate a first modified form of the grip structure designed in accordance with the present invention, which has the grip area of the oval sectional shape, an inclined Otafuku shaped grip end that is inclined from the grip end for the bottom hand for contact with the little finger tip and the little finger second joint, and the lock structure disposed at the boundary between the grip are and the grip end for locking the bottom hand;

[0028] FIGS. 6A-6C illustrate a second modified form of the grip structure designed in accordance with the present invention, which has the grip area of the oval sectional shape, an inclined Otafuku shaped grip end that is inclined from the grip end for the bottom hand for contact with the little finger tip and the little finger second joint and also a palmar end below the little finger third joint, and the lock structure disposed at the boundary between the grip are and the grip end for locking the bottom hand;

[0029] FIGS. 7A and 7B illustrate a third modified form of the grip structure designed in accordance with the present invention, in which FIG. 7A shows the bat in its entirety, the locking mechanism being formed at the boundary between the inclined Otafuku shaped grip end that is inclined for contact with the little finger tip and the little finger second joint and the palmar end below the little finger third joint, in which lower three fourths (¾) of the grip area is formed to represent an oval sectional shape and forms a palm grip for contact with the oblong oval shape varying to the circular sectional shape in a direction towards a sloped portion, and FIG. 7B illustrates a longitudinal sectional view thereof;

[0030] FIG. 8A illustrates an enlarged diagram of the grip portion of the bat shown in FIGS. 7A and 7B, FIG. 8B illustrates an end view thereof, and FIG. 8C illustrate respective cross sectional views taken along the lines A-A, B-B, C-C and D-D, respectively;

[0031] FIG. 9 is a perspective view showing a third modified form of the present invention, showing a manner in which the grip area is grasped by the bottom hand and the top hand and in which, although the bottom hand assumes a palmar grip, the top hand assumes a semi-palmar grip with the thumb and the index finger opened, to enable a firm grip to be accomplished during the down swinging and for women's soft ball games.

[0032] FIG. 10 is a perspective view showing only the grip portion of the bat designed in accordance with the third modification of the present invention, in which the grip end is of a design in which a lower end portion thereof coincides substantially with the grip contour and is inclined at an angle of 20, 25 or 30 degree relative to the vertical line lying perpendicular to the longitudinal axis of the bat while outer and left and right ends thereof are somewhat swelled outwardly from the perimeter of the grip portion of an oval sectional shape along the inclined surface in the grip end. Thereby, the grip upper end forms the locking structure for the bottom hand while the left and right ends of the grip end are so shaped as to avoid the drop-out of the little finger tip and a palmer end below the little finger third joint, thereby completing the structure for maintaining the bottom hand in a locked condition.

[0033] FIG. 11 is an explanatory diagram to show the function of the conventional bat.

[0034] FIG. 12A is a perspective view of the bat structure according to the present invention and FIG. 12B is a longitudinal sectional view.

[0035] FIG. 13A is a perspective view showing a manner of the grip being grasped according to the present invention.

[0036] FIG. 13B is a cross sectional view taken along the line B-B in FIG. 13A.

[0037] FIG. 13C is explanatory diagrams showing respective conditions of the bottom hand and the physical angle that are exhibited at the time of impact at the inside (1), the middle (2) and the outside (3) of a right-handed batter then gripping the bat in the manner shown in FIG. 13A.

[0038] FIG. 14 is an explanatory diagram showing displacement of the batting centroid caused by displacement of the center of gravity, brought about by addition of a weight to the head of the bat and by displacement of the center of grip.

BEST MODES FOR CARRYING OUT THE INVENTION

First Preferred Embodiment 1

[0039] Hereinafter a first preferred embodiment of the present invention will be discussed.

[0040] Referring to FIG. 1, there is shown a side view of a baseball bat in its entirety, which bat includes a bat head H, a bat barrel portion B, a bat throat portion, a bat grip portion G and a grip end E. The bat in its entirety is made of wood and, although an end face of the bat head represents a circular shape, a grip end face represents a Japanese Otafuku shape (a generally trochoidal shape) that is generally similar to the oval shape having its opposite sides bulged outwardly, and is so formed as to have the shape changing from an oval section at the grip area to an exact circle at the throat area on one side of the center of the bat grip area opposite to the bat barrel B.

[0041] When a predetermined weight ΔM is added to the bat head H, the center of gravity C of the bat is displaced from the original position, which lies at the bat barrel B, by a quantity Δa in a direction towards the batting centroid P, and, therefore, the kinetic energy applied to the center of gravity increases.

[0042] On the other hand, the barrel extends to the grip area G through the throat area T, with a generally oval shaped section represented over to the grip end E and, also, with a curved angle α being formed on a grip surface on an outside with respect to a center axial line that extends in the lengthwise direction, thereby completing a locking structure R. As a result that this locking portion R causes a left hand grip (bottom hand) of the right handed batter from a little finger side to a thumb side, the left hand wrist is urged counterclockwise to press, as shown by the arrow in FIG. 2, to keep the forearm of the bottom hand and the bat at a right angled relationship so that return of the back of the batter's left hand can be suppressed during the bat swinging and, also, bending of an elbow of the left hand is suppressed during the impact. Also, at a semiperimetric portion of the grip area then grasped by the palm of the bottom hand, the gripping coefficient of friction is increased. On the other hand, if in an upper region of the grip area ranging from the grip center to the throat area the coefficient of friction of that region is so increased as to bring the second joint of a finger of the top hand in between the second joints of fingers of the bottom hand and the roots of the fingers thereof, the top hand grasps the bat grip area under the finger grip (See FIG. 13A) so that the back of the bottom hand and the back of the top hand come to be parallel to each other. This is a condition in which in order to match the right angled relationship between the forearm of the bottom hand and the forearm of the top hand with the plane of swinging oriented towards a ball along a line from the shoulder to the arm and bat, the bat gripping creates three right angled relationships (1) between both arms, (2) between one of the arms and the bat and (3) between the other of the arms and the bat, respectively, so as that those three right angled relationship can be utilized to accomplish a sort of swing “to put the bat out from inside” along the line of the bottom hand.

[0043] The three right angles referred to above includes (1) the first right angle (FIG. 3A) between the forearm of the bottom hand and the bat (FIG. 3A), (2) the second right angle between the forearm of the bottom hand and the forearm of the top hand (FIG. 3A), and (3) the third right angle between the forearm of the top hand and the bat (FIG. 3B). Particularly, when the bat is in the top position, creating of the substantially right angled relationship between the forearm of the bottom hand and the bat, has extremely important implications and that is why the bat shown in (A) to (D) of FIG. 4 is so close towards the shoulder tip (acromion) that no change between it and the shoulder tip happens totally and a substantially right angled grip is kept and rather rotating power in most conditions is drawn thereby. Accordingly, putting the batr out from inside can be accomplished. In contrast thereto, if the angle between the bottom hand and the bat is obtuse when the bat is held in “top”, that is, the forearm of the bottom hand and the bat cooperate to form the obtuse angle when the bat is held in “top”, even though the length of time from the start of bat swinging to impact will become small, the bat head is apt to open on the side of a catcher from the beginning and, therefore, a sufficient distance of acceleration to the impact cannot be secured with the speed of movement of the bat head during the impact consequently failing to increase and, since the head is opened from the beginning, the bat head will quickly return under the outside pitch, constituting a cause of trick swinging. Accordingly, to maintain the substantially right angled relationship of the angle between the forearm of the bottom hand and the bat at the time the bat is held top, it will readily be seen that gripping a grip lower region with the bottom hand under the palmar grip is important.

[0044] Then, the right angle delimited between the forearm of the bottom hand and the forearm of the top hand controls both the rotation of the upper body and the respective movements of those arms which occur during the batting action and thus changes with the rotatory movement of the upper body brought about by the scapular movement, rather than being moved accompanied by the movements of the forearms. Accordingly, movement of both forearms while intersecting at right angles to each other results in the movement of the upper body at the time of start of swinging to draw the bat by the rotatory action along the line of the bottom hand without changing the distance from acromion to acromion (FIGS. 4B and C), thereby creating the behavior “to put the bat out from inside”. The right angle between the forearm of the bottom hand and the forearm of the top hand brings about the behavior “to put the bat out from inside”, in which the line ranging from the shoulder to arm of the bottom hand and to the bat can be matched with the plane of swinging the hand back of the bottom hand becomes parallel to the hand back of the top hand, when while the palmar grip is realized on the bottom hand, the bat grip area is gripped by the top hand under the palmar grip or finger grip so that the second joint of fingers of the top hand may come in between the second joint of the fingers and the root of the fingers of the bottom hand

[0045] The grip structure in the bat referred to above is such as to have a shape varying from the grip end to the grip area, with the oval shape varying gradually to the circular shape, and, in the case of the oval shape, a top peripheral edge forms an inclined portion, but a region from a top peripheral edge to a lower peripheral portion of the grip end is flared wherefore a little finger side and a palmar side of the bottom hand is easy to be slipped. Accordingly, according to a first modification of the present invention, an intermediate area of the grip end is formed as a curved step portion to follow the contour of the little finger to improve the locking mechanism so that the palm of the bottom hand may not fall off from the grip end. FIGS. 5A-5C illustrate the grip structure designed for this purpose. FIG. 5A illustrates an end view showing an end face of the grip end, in which a portion of the grip end ranging from the top peripheral edge to an intermediate area of the semicircular bottom hand side is bulged outwardly and then curved to define a locking structure. This condition is best shown in the end view of FIG. 5A and the cross section view of FIG. 5C which is taken along the line A-A. In other words, in the end view of FIG. 5A, it represents a condition approximating to a Japanese Otafuku shaped oval sectional shape, and, as comparison with the following sectional view taken along the line A-A, a first curved step portion is formed in the top peripheral edge that may contact the second joint of the bottom hand so that the wrist is somewhat cocked having been turned counterclockwise. A zone from an upper peripheral edge to an intermediate peripheral edge is bulged outwardly and an inclined step portion is formed from the end towards the grip and thereby the back of the bottom hand is turned counterclockwise from a little finger side to a thumb finger side. Accordingly, the little finger side of the bottom hand can grip firmly under a power grip without falling off from the grip end and the forearm of the bottom hand comes to be maintained at right angles to the longitudinal axis of the bat.

[0046] FIG. 6 illustrates an improvement in and over the modification shown in and described with reference to FIGS. 5A-5C, which is so designed as to prevent the drop-out from the grip end on the palmar side of the bottom hand then under the power grip and as to maintain the power grip by the bottom hand. In other words, according to the second modification now under discussion, a peripheral portion at the vicinity of the grip end is bulged not only in an upper portion, but also in the both intermediate peripheral edges along a contact portion for the little finger tip and a contact portion for the lower palm of the little finger third joint to thereby prevent the drop-out of the palmar end of the bottom hand and the little finger side from the grip end to thereby increase the gripping force. The bat having the above described structure is shown in FIGS. 6A-6C. FIG. 6A illustrates an end view showing the end face of the grip end having the locking structure formed therein while an area ranging from the upper peripheral edge of the semi-perimeter on the bottom hand to the intermediate peripheral edge is curved down in a direction towards the grip area. This condition is shown in the end view of the end face shown in FIG. 6A and the cross section taken along the line A-A in FIG. 6C. In other words, in the end view of FIG. 6A, a condition is shown which approximates to the generally trochoidal (Japanese Otafuku shaped) sectional shape and, as comparison with the cross-sectional diagram taken along the line A-A, a first curved portion is formed in an upper peripheral edge on which the second joint area of the bottom hand rests with the wrist being locked having been somewhat cocked counterclockwise. In FIGS. 6A-6C, not only the area ranging from the upper peripheral edge to the little finger tip, but also the opposite intermediate peripheral edge of the palmar end below the little finger third joint, are formed with an inclined step portion extending from the grip end to the grip area and, thus, the back of the bottom hand is locked having been somewhat lifted counterclockwise from the little finger side towards the thrum side. Accordingly, the palmar side of the bottom hand can be gripped under the power grip firmly without falling out from the grip end and the forearm of the bottom hand can be maintained at right angles to the longitudinal axis of the bat.

[0047] As can readily be understand from the description made with reference to FIGS. 3A and 3B and FIGS. 4A to 4D, it is clear that (1) the first necessary task is to enable gripping in which the angle between the forearm of the bottom hand and the bat to be substantially right angles to each other at the time of the top position under the palmar grip with the bottom hand, and, (2) secondly, it is important to grip the bat grip area under the palmar grip or the finger grip with the top hand so that the finger second joint of the top hand can be brought in between the finger second joint and the finger root against the palmar grip of the bottom hand so that the forearm of the bottom hand and the forearm of the top hand may be right angled relative to each other. One of the objects of the present invention is to provide the grip structure effective to accomplish such a gripping as described above and is of a grip structure having, firstly, a region effective to increase the coefficient of friction necessary to accomplish such gripping as discussed above and, secondly, the gripping is accomplished under the right-angled relationship between the bottom grip and the bat.

[0048] The grip structure shown in FIGS. 7 to 9 is such that, in the bat grip area, the bottom hand grip ranging at least from the grip end to the grip center has a generally oval sectional shape in a plane perpendicular to the bat longitudinal axis; a grip portion for the top hand ranging at least from the middle finger to the little finger is rendered to represent a generally oval sectional shape in the plane perpendicular to the bat longitudinal axis; and a region transiting therefrom to the throat area includes the inclined area in which the oval sectional shape is transmitted to the circular section represented by the throat area. This lies in the bat grip structure of the type in which (1) the palm of the bottom hand is engaged with the grip end under the palmar grip and, on the other hand, (2) the middle finger to the little finger of the top hand is gripped to achieve a controllable palmar grip, and (3) the bottom hand is displaced in a direction towards the bat head under the palmar grip while the top hand is also displaced to grip the bat from the inclined portion. With the bottom hand and the top hand gripped under the palmar grip, downswing can be readily exercised, the grip suited for use in the women's soft ball game can be realized; selection of the bottom grip to grip under the palmar grip and the top hand to grip under the finger grip can be made; and thereby the batting centroid can be changed from Pc to Pc1 by displacing the grip center from Gc to Gc1 (FIG. 14).

[0049] The locking structure according to this embodiment now under discussion is formed (1) by causing either an upper end of the grip end to follow the finger pulp, (2) followed by somewhat bulging the little finger tip side of the grip end so that the region from the upper end of the grip end to both opposite ends thereof may brought into contact with the grip end, or (3) the little finger tip and the palmar peripheral end below the little finger of the grip end and so that the little finger tip of the bottom hand and the palmar end below the little finger may be brought into contact with the grip end. For this reason, the grip end represents the Japanese Otafuku shape with each corner portion inclined inwardly from the grip end so that the second joint of the bottom hand as well as the little finger tip side and the palmar end side can be reinforced to avoid the bottom hand slip-out from the grip end. It is to be noted that the lower end of the grip end is not necessarily bulged outwardly, but if the end grip is so shaped as to have an angle option of taking 20, 25 or 30 degree relative to the vertical line (FIG. 10), the locking strength of the grip can be increased.

[0050] Also, the region operable to increase of the coefficient of friction in the grip area is formed in at least an intermediate portion and in the vicinity thereof of the semicircular portion of the bottom grip portion that is grasped by the palm of the bottom hand so that gripping of the grip lower region (bottom) can be facilitated under the palmar grip of the bottom hand. With respect to the top hand, the region operable to increase the coefficient of friction in the grip area may be formed in at least an intermediate portion and in the vicinity thereof of the semicircular portion of the grip that is gripped by the palm corresponding to the middle finger, the third finger and the little finger so that gripping of the grip upper region (bottom) can be facilitated under the palmar grip of the top hand.

Second Preferred Embodiment

[0051] Hereinafter, a second preferred embodiment of the present invention will be discussed in detail.

[0052] FIG. 11 is a side view showing the baseball bat in its entirety, which includes a bat head H, a bat barrel portion B, a bat throat portion T, a bat grip portion G and a grip end E.

[0053] The bat in its entirety is made of wood and, one of ten adjustment cap type heads M is added to the bat head H of a standard weight so that the weight added to the bat head may be adjusted to a value, for example within the range of 10 to 100 grams. Although the end face of the bad head is circular, the grip end face is non-circular such as, for example, oval or egg-shaped.

[0054] Mechanical Analysis of the Batting on the Bat Structure

[0055] A predetermined weight ΔM is added to the bat head H. Thereby, the center of gravity C of the bat, which lies in the bat barrel portion, is displaced a distance Δa from the original position towards the batting centroid P (See FIG. 14). In contrast thereto, the batting centroid P does not virtually displace and, hence, the position of the sweet spot of the bat, which is located at a position adjacent the batting centroid with respect to the center of gravity C does not displace correspondingly. Therefore, since the kinetic energy F applied to the center of gravity C is increased by the distance Δa from the center Q of gripping by the quantity of displacement of the center of gravity of the parameter I (inertia moment), the kinetic energy is increased by a quantity Δa+ω even though the angular velocity ω does not change. Moreover, consequent upon approach of the center of gravity C towards the batting centroid P, it has been dynamically ascertained that the kinetic energy acting on the center of gravity C is so apt to be affected by the sweet spot that the kinetic energy applied to the ball then hitting the sweet spot may be assuredly increased.

[0056] On the other hand, the barrel portion B extends through the throat portion T to the grip portion G, over the grip end the non-circular sectional shape, for example, the oval sectional shape is represented and an inclination angle α is formed in a grip surface on an outer side relative to the longitudinal axis of the bat. The locking portion R of the oval sectional shape render the left hand of the right-handed batter to grip with its little finger side to the thumb side inclined and with the left-hand wrist being locked having been urged counterclockwise to thereby suppress the return of the back of the left hand during the bat swinging and also to suppress the bending of the left hand elbow during the impact. This leads to the action of “swinging the bat as if hitting with the grip” and brings about such a result as to increase the angular velocity of swinging of the bat. The angle of inclination a relative to a center line of a flared portion F is preferably increased with increase of the weight ΔM of the bat head. That is because, as the center of gravity displace towards the bat tip end, the back of the left hand during the bat swinging tends to return with the inertia force acting thereon.

[0057] As discussed above, when the right handed batter swings the bat accompanied by the rotation of the batter's physical body without returning the left hand palm and then hits the ball with the left arm elbow straightened steadily, the action “to swing the bat as if hitting the grip of the bat” can be accomplished and the maximum angular velocity that can be achieved by such batter can be exhibited. Also, although it has hitherto been suggested to initiate the swinging at an early state in order to hit the inside pitch, to hit the ball close to the pitcher and to delay the start of swinging so that the outside pitch can be hit, it is quite difficult since the timing of start of the batting is not the same. However, if the bat of the structure according to the present invention, the action “to swing the bat as if hitting the grip” can be accomplished and, therefore, the swinging can be simply accomplished with the impact point aligned in a line regardless of the tight, middle and inside balls (FIG. 13C).

[0058] The grip portion of the bat referred to hereinabove is such that the shape thereof varies from oval to circular from the grip end towards the grip center, and, although in the case of the oval shape the inclined portion is formed in the upper peripheral edge, if from the upper peripheral edge down to the lower portion of the grip end the side surface is flat with no step formed therein, the little finger side of the bottom hand is apt to slip since the end is nor raised up. In view of this, in the practice of the second preferred embodiment of the present invention, it is recommended to employ any one of the various grip structures shown and described in connection with the previously described first embodiment of the present invention. In particular, if the grip portion G of the bat is of the structure in which 1)′ when the bat grip portion G is 1)′ in which the palm of the bottom hand is brought into contact with a portion of the grip portion G which ranges from the grip end to the bat throat portion T, another portion of the grip portion ranging from the palm of the bottom hand to the middle finger of the upper hand represents a generally oval shape of which sectional surface perpendicular to the longitudinal axis of the bat is suited for the palmar grip and, in a direction upwardly over the middle finger of the upper grip a double stepped grip is formed in which the circular sectional surface of the bat throat portion is changed from the grip portion oval sectional shape; moving the grip center Gc to Gc1, selection of one of a finger grip and a half palmar grip in which, while the palmar grip for the bottom hand is secured, the little finger and the thumb finger in the grip is released, is possible, the batting centroid Pc is preferably adjustable to Pc1 and, yet, at least the intermediate portion of the semiperimetric portion of the grip portion that is gripped by the bottom hand and the upper hand and in the vicinity thereof 3) the region required to increase the coefficient of friction of the grip is preferably formed to reinforce the palmar grip.

[0059] According to the present invention hereinabove fully described, the kinetic energy F at the sweet spot during the bat swinging can be increased and the swinging can be corrected so that the maximum angular velocity can be attained during the bat swinging. Therefore, by the cumulative effects thereof, the maximum batting efficiency can be attained.

[0060] In any event, while the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein.