Composite bat structure

Abstract

[Problem] To supply a composite type bat structure for achieving maximum hitting efficiency [Solution] A composite type bat structure comprises a barrel portion made from a metal cylindrical body for forming a center of percussion, a cap portion attached to the distal end of the barrel portion, a throat portion extending from the rear end of the barrel portion to a grip portion, and the grip portion made from fiber-reinforced plastic (FRP) and having a grip end on the rear end; wherein a distal end opening of the barrel portion comprising the hollow metal cylindrical body is closed by the cap portion, with a prescribed weight being added to the cap portion, so that the center of gravity of the barrel portion in the lower barrel portion is moved toward the distal end of the bat. The FRP grip portion and the FRP grip end are formed separately from each other, thereby allowing an atypical grip shape to be easily formed. The atypical grip has the function of locking the bottom hand at a hitting swing. The distal end of the grip portion is extended and connected integrally to the throat portion, where the rear end of the barrel portion and the distal end of the grip end are connected via a vibration damping coupling part that has a vibration damping ratio smaller than the grip portion and larger than the barrel portion metal. Thus, the composite type bat structure allows players to realize a better hitting efficiency and to minimize a shock at the time of a hitting impact.

1 . A composite type bat structure which comprises
 a barrel portion for forming a center of percussion,   a grip portion having a grip end at the rear end, a throat portion extending from the barrel portion to the grip portion,   the barrel portion and the grip portion being connected with a connection member for forming the throat portion so as to form a three-piece composite type bat,   wherein the barrel portion is made from a hollow metal cylindrical body having a higher specific gravity than the grip portion, and   the distal end opening of the barrel portion is closed by the cap portion, while the grip portion is made from a FRP having a specific gravity lighter than the barrel portion,   whereby the center of gravity positioned at the bottom of the barrel portion can be shifted to the distal end of the barrel portion, while the grip portion is provided with a function of locking the bottom hand, and the connecting member is integrated with extension of the grip portion to make the throat portion,   whereby the connecting portion has a vibration damping factor lower than the grip portion, and larger than the barrel portion so as to be a vibration attenuation rate part for connecting the barrel portion rear end with the tip of the grip portion,   wherein the metal barrel portion for forming a center of percussion is made of aluminum or an aluminum alloy,   the throat portion extending from the barrel portion rear end to the grip portion is made from a material selected from the high strength and high elastic resins consisting of a para-aramid resin (Kepler), an ultrahigh molecular weight polyethylene resin, a PAR resin (PolyArylate resin), a PBO resin, and a Carbon resin, and the grip portion is made from a material selected from FRPs consisting of a PAN-based fiber FRP, a Pitch-based fiber FRP, a glass fiber-based FRP, an Aramid fiber-based FRP, and a Silicon carbide fiber-based FRP, and   wherein the barrel portion lower end is constructed to engage with on a lower outer periphery of the connecting part, while the grip portion upper end is constructed to engage with an upper inner peripheral of the connecting part to form a three-layer joint structure.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The bat structure as claimed in  claim 1 , in which
 the FRP grip is made of a grip end part provided with a hole for receiving a grip part, an inclined portion R and four bulged portions protruding outwardly in four directions against the grip axis to form the enforcing portions which engages with a tip of the little finger and/or a palm below the third joint of the little finger of the bottom hand so as to prevent the little finger or the palm of the bottom hand from slipping out from the grip end as shown in  FIGS. 16 and 17 .   
     
     
         5 - 6 . (canceled) 
     
     
         7 . The bat structure as claimed in  claim 1 , in which
 the bat grip portion G is designed in a two stepped grip such that a bottom grip portion ranging from the grip end to the center of the grip as well as an upper grip portion from the center of the grip to the middle finger of the upper hand is a generally oval sectional shape perpendicular to the longitudinal axis of the bat, and an upper grip portion over the middle finger of the upper grip is an inclined portion in a direction upwardly of the bat 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; and in that, 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 with a palmer grip, thereby adjusting the batting centroid.   
     
     
         8 - 10 . (canceled) 
     
     
         11 . The bat structure as claimed in  claim 7  in which the two stepped grip portion formed by a combination of a cylindrical grip parts GP of FRP, a semi-cylindrical auxiliary grip parts G- 1 , an inclined parts G- 2  for being used to open the thumb and the forefinger of the upper hand and an end parts E provided with bulge portions inclined to the axis of the grip portion and protruded in four directions for keeping the bottom hand under the palm grip.