Abstract:
A dual-bearing reel has a rotatable pinion with a gear train driven by a rotating handle, a spool rotatable in the direction of the rotating handle by transferring a rotational force from the pinion to a spool shaft. The pinion and spool shaft are made so that releasing the pinion from the spool shaft allows the spool to rotate freely.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a dual-bearing reel called as a bait casting reel, and more particularly to a dual-bearing reel including a mechanism for inducing free rotation of a spool. 
     2. Description of the Related Art 
     Dual-bearing reels are generally constructed in such a way that a pinion is rotated with a gear train driven in response to the rotation of a handle, and a spool is rotated in the winding direction by transferring the rotating force of the pinion to a spool shaft. 
     On using such a dual-bearing reel, in order to obtain a maximum effect of the casting, the spool is maintained in such a manner of that little friction force is applied to the spool. Specifically, during the casting, if the thumb-bar provided on a reel body is pushed down, the pinion is disengaged with the spool shaft, thereby allowing the spool shaft to freely rotate. 
     With the construction of the prior dual-bearing reel including a mechanism for inducing free rotation of a spool, although the pinion is released from the spool shaft, there is a friction between the inner periphery of the pinion and the outer periphery of the spool shaft, thereby causing the free rotation of the spool to be limited. Therefore, since an idle run of the spool is not smooth, the casting distance is reduced, and a noise is produced. 
     SUMMARY OF THE INVENTION 
     Accordingly, to solve the problems stated above, an object of the present invention is to provide a dual-bearing reel including a mechanism for inducing free rotation of a spool, which a friction between an inner periphery of a pinion and an outer periphery of a spool shaft is minimized in a state that the pinion is released from the spool shaft. 
     To achieve the above and other objects, according to one aspect of the present invention, there is provided with a dual-bearing reel including a pinion rotatable with a gear train driven in response to a rotation of a handle, and a spool rotatable in the winding direction by transferring a rotating force of the pinion to a spool shaft, in which the release of the pinion from the spool shaft causes the spool to rotate freely: wherein the spool shaft has a large diameter portion, a stepped portion, and a small diameter portion, with the small diameter portion being interposed between the large diameter portion and the small diameter; and wherein the pinion has an enlarged groove on inner periphery of a hole, the hole being received with the large diameter portion of the spool shaft; such that when the pinion is engaged to the spool shaft to transfer the rotating force to the spool shaft, the hole is in contact with the large diameter portion and the stepped portion of the spool shaft, and when the pinion is released from the spool shaft to idly rotate the spool shaft, the stepped portion of the spool shaft is positioned in the enlarged groove of the pinion. 
     According to other aspect of the present invention, there is provided with a dual-bearing reel including a pinion rotatable with a gear train driven in response to a rotation of a handle, and a spool rotatable in the winding direction by transferring a rotating force of the pinion to a spool shaft, in which the release-of the pinion from the spool shaft causes the spool to rotate freely: wherein the spool shaft has first and second stepped portions and a small diameter portion between the stepped portions; and wherein the pinion a groove for receiving the first stepped portion of the spool shaft, and a hole for supporting the second stepped portion; such that when the pinion is engaged to the spool shaft to transfer the rotational force to the spool shaft, the first and second stepped portions of the spool shaft are in contact with the groove and the hole the pinion, respectively, and when the pinion is released from the spool shaft to idly rotate the spool shaft, the second stepped portion of the spool shaft is positioned in the hole of the pinion. 
     The pinion has an enlarged groove such that the second stepped portion of the spool shaft is positioned in the hole of the pinion. 
     According to another aspect of the present invention, there is provided with a dual-bearing reel including a pinion rotatable with a gear train driven in response to a rotation of a handle, and a spool rotatable in the winding direction by transferring a rotating force of the pinion to a spool shaft, in which the release of the pinion from the spool shaft causes the spool to rotate freely: wherein the spool shaft has a large diameter portion, a stepped portion, and a small diameter portion, with the small diameter portion being interposed between the large diameter portion and the small diameter; and wherein the pinion has an enlarged groove on an inner surface of a hole, into which the large diameter portion and the stepped portion of the spool shaft are inserted, an annular boss on one side of a pin latching groove, and a protruded arm on the other side of the pin latching groove opposite to the annular boss, the protruded arm having a slanted surface on an outer edge thereof, such that when the pinion is released from the spool shaft, the annular boss of the pinion is inserted into a stepped portion of a cam plate, and the slanted surface of the protruded arm is the slanted surface of the protruded annular portion  3 a formed on a side cover, thereby automatically centering the slanted surfaces arm. 
     According to still another aspect of the present invention, there is provided with a dual-bearing reel including a pinion rotatable with a gear train driven in response to a rotation of a handle, and a spool rotatable in the winding direction by transferring a rotating force of the pinion to a spool shaft, in which the release of the pinion from the spool shaft causes the spool to rotate freely: wherein the spool shaft has a large diameter portion, a stepped portion, and a small diameter portion, with the small diameter portion being interposed between the large diameter portion and the small diameter; and wherein the pinion has an enlarged groove on an inner surface of a hole, into which the large diameter portion and the stepped portion of the spool shaft are inserted, an annular boss on one side of a pin latching groove; such that when the pinion is released from the spool shaft, the annular boss of the pinion is inserted into a stepped portion of a cam plate and is supported thereby. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects, other features and advantages of the present invention will become more apparent by describing the preferred embodiment thereof with reference to the accompanying drawings, in which: 
     FIG. 1A is a cross-sectional view of a dual-bearing reel according to the invention. 
     FIG. 1B is a magnified view of the spool of the reel in FIG.  1 A. 
     FIG. 1 is a cross-sectional view illustrating the assembled state of a dual-bearing reel according to the present invention. 
     FIG. 2 is a cross-section view illustrating the state that a pinion is released from a spool shaft. 
     FIGS. 3 and 4 are enlarged views illustrating the state that a pinion is engaged to and released from a spool shaft, respectively. 
     FIG. 5 is an exploded view illustrating the construction of a dual-bearing reel according to the present invention. 
     FIGS. 6 and 7 are enlarged views of an alternative embodiment of the present invention. 
     FIGS. 8 and 9 are enlarged views of other alternative embodiment of the present invention. 
     FIGS. 10 and 11 are enlarged views of another alternative embodiment of the present invention. 
     FIGS. 12 and 13 are enlarged views of still another alternative embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The construction and operation of the present invention will be explained in detail with reference to the accompanying drawings. 
     As seen in FIG. 3, spool shaft  5  has a large diameter portion  5   a  and a stepped portion  5   b . Small diameter portion  5   c  is interposed between the large diameter portion  5   a  and stepped portion  5   b.    
     When a pinion  8  is engaged to the spool shaft  5 , a hole  8   a  is in contact with the large diameter portion and the stepped portion  5   b  of the spool shaft. An end of an arm  5   d  extended from the stepped portion  5   b  is in contact with a washer  17  of a brake force controlling knob  16 , and has a diameter same or smaller than that of the small diameter portion. When the pinion  8  is released from the spool shaft  5 , the hole  8   a  of the pinion  8  does not intervene the spool shaft, and the stepped portion  5   b  of the spool shaft is positioned in an enlarged groove  8   b  of the pinion, as shown in FIG.  4 . Therefore, when a spool rotates idly, the spool shaft  5  can be rotated freely without being intervened from any components. 
     As shown in FIG. 2, when the pinion  8  is released from the spool shaft  5 , however, any portion of the pinion  8  (the hole  8   a ) may be in contact with the spool shaft, due to a vibration, of which is generated when the spool rotates in a very high speed. Such a friction is a negligible value. 
     FIG. 6 illustrates an alternative preferred embodiment of the present invention. When a pinion  120  is engaged to a spool shaft  100 , a hole  8   k  of a pinion is in contact with a stepped portion  101  of the spool shaft, and a stepped portion  102  is in contact with a hole  122  of the pinion. When the pinion is released from the spool shaft, the stepped portion  102  of the spool shaft is positioned in a hole  121  of the pinion, as shown in FIG.  7 . 
     FIG. 8 illustrates other alternative preferred embodiment of the present invention. A hole  141  of a pinion is provided with an enlarged groove  143 , in the embodiment of FIG.  6 . When the pinion is released from the spool shaft, the stepped portion  102  of the spool shaft is positioned in the enlarged portion  143  of the pinion, and a hole  142  of the pinion is in contact with the stepped portion. 
     FIGS. 10 and 11 are enlarged views of another alternative preferred embodiment of the present invention. When a pinion  200  is released from a spool shaft  5 , the spool shaft is not in contact with any portion of the pinion. 
     Specifically, a side cover  3  has a protruded annular portion  3   a , and a slanted surface  3   b  on an inner flange thereof A hole of a cam plate  10  is provided with a stepped portion  10   a . The pinion has an enlarged groove  202  on an inner surface of a hole  207 , into which a large diameter portion  5   a  and a stepped portion  5   b  of the spool shaft are inserted, an annular boss  203  on one side of a pin latching groove, and a protruded arm  500  on the other side of the pin latching groove opposite to the annular boss  203 . The protruded arm has a slanted surface  501  on an outer edge thereof. 
     When the pinion is engaged to the spool shaft, the large diameter portion  5   a  and stepped portion  5   b  of the spool shaft are in contact with the hole  207  of the pinion. When the pinion is released form the spool shaft, the annular boss  203  of the pinion is inserted into the stepped portion  10   a  of the cam plate  10 , and the slanted surface  501  of the protruded arm  500  is the slanted surface  3   b  of the protruded annular portion  3   a  formed on the side cover  3 , thereby automatically centering the slanted surfaces arm and significantly reducing the frictional coefficient between the spool shaft and the pinion. At that time, it is noted that the stepped portion  5   b  of the spool shaft is positioned in the groove  202  of the pinion. The pinion  200  is supported by means of the protruded annular portion  3   a  and the stepped portion  10   a . In particular, the function of centering the slanted surfaces  501  and  3   b  causes the pinion to be prevented from the vibration, even though the spool is vibrated. 
     FIGS. 12 and 13 are enlarged views of still another alternative embodiment of the present invention, wherein the protruded annular portion  3   a  of the side cover and the protruded arm  500  of the pinion in the above embodiment are omitted, and wherein the construction causes the side cover to assemble. 
     Although the present invention has been described with reference to the drawings, it is understood that this description is not to limit the present invention to the embodiments shown in the drawings but simply to explain the present invention. One skilled in the art will understand that various changes and modifications can be made from the embodiments disclosed in the specification. Therefore, the scope of the present invention should be defined by the appended claims.