Spinning reel for fishing with a rotor partially reduced in wall thickness.

In a spinning reel, the rear portion of the inner periphery of a large-diameter cylindrical portion and base portion of the rotor on the .beta. side of the rotor are formed into a thin-walled portion with a recess as compared with the rear area .alpha. of the rotor. The rear area .alpha. is closer to the bail support arm having a fishline guide portion than to the other bail support arm and is within the fishline winding side of the semi-annular bail arm. Furthermore the bail support arms and the bail support members are offset by a distance D with respect to the center of the rotary shaft of the rotor. This arrangement improves not only fishing operability, by stabilizing the rotational balance of the rotor without increasing the weight of the reel body as a whole but also improves fabrication efficiency by reducing the number of parts needed, since a discrete balance is no longer needed.

BACKGROUND OF THE INVENTION 
The present invention relates to a spinning reel for fishing designed to 
stabilize the rotational balance of a rotor. 
A typical conventional spinning reel for fishing is constructed such that a 
pair of bail support arms are respectively formed from the rear to front 
part of the cylindrical portion of and on both sides of a rotor, a 
semi-annular bail arm is fitted to the leading end portions of the pair of 
bail support arms via bail support members such as a bail holder and an 
arm lever having a fishline guide portion. The semi-annular bail arm is 
reversible between a fishline winding position and a fishline playing-out 
position. 
Such spinning reel suffers from a problem in that the axial and rotational 
balance of the rotor is, adversely affected by the weight imbalance causes 
by both the shape and location of the semi-annular bail arms and the bail 
support members. For instance these bail arms and bail support members may 
project forward or may not be formed bilaterally symmetrically. 
Japanese Utility Model No. 3002014 and Japanese Patent Laid-Open 
Publication No. 197670 disclose balancing, as shown in FIGS. 10 to 13, 
which attempt to solve such inferior rotational balance. 
As shown in FIGS. 10 and 11, a balancer 7 for keeping longitudinal balance 
in the axial direction is provided in the rear end portion (when the bail 
is positioned for fishline rotor 2' on the bail side of a winding). 
Additional a balancer 8 is provided on the bail playing-out side higher up 
on the rotational axes than the balancer 7. This stabilizes the rotational 
the rotational balance of the rotor by correcting the imbalance in weight 
as viewed from a direction perpendicular to the rotary shaft 10 of the 
rotor and reducing vibrations during the rotational operation. 
In FIGS. 12 and 13, balancers 7, 9 for keeping longitudinal balance in the 
axial direction are provided in the rear end portion, in the fishline 
rotor 2' on the bail side of a winding position. The rotor 2' is installed 
in such a way that it is offset by a dimension D with respect to its 
rotary shaft 10. As a result, the rotational balance of the rotor is 
stabilized by correcting the imbalance in weight as viewed from a 
direction perpendicular to the rotary shaft 10 and reducing vibrations 
during the rotational operation. 
Notwithstanding, the rotor, and thus also as a whole, the reel, becomes 
heavier because the bail side in the rear end portion of the rotor 
projects outward, and because the balancer is composed of a material 
having high specific gravity such as lead, is rigidly and separately 
secured thereto. Consequently, the fishing operability is lowered, and the 
provision of the separate balancer results in increasing the number of 
parts, thus lowering fabrication efficiency. 
Moreover, another problem arises from the a balancer that projects in that 
the configuration of the rear end portion of the rotor is restricted. 
Accordingly, the drawback encountered in the prior art include the lowered 
fishing operability as the reel as a whole becomes heavier due to the 
provision of the balancer as a separate body, the associated increase in 
the number of parts, and the resulting lowered fabrication efficiency. 
SUMMARY OF THE INVENTION 
In view of the foregoing shortcomings, an object of the present invention 
is to provide a spinning reel for fishing designed to stabilize the 
rotational balance of a rotor. Further objects are improving the fishing 
operability without increasing the weight of the reel as a whole or the 
number of manufacturing parts. Yet another object is increasing 
fabrication efficiency by dispensing with a balancer as a separate body. 
A spinning reel for fishing according to the present invention comprises: a 
pair of bail support arms formed on a rotor rotatable in accordance with 
rotation of a handle; and bail support members, one of which has a 
fishline guide portion, being supported on the leading end portions of the 
bail support arms. The bail support members are reversible between a 
fishline winding position and a fishline playing-out position, wherein the 
pair of bail support arms are deflected or offset from the center of the 
rotary shaft of the rotor to the fishline playing-out side of the bail. 
The the rear portion of the rotor on the side facing, across the rotary 
shaft of the rotor, the rear area of the rotor on the side of the bail 
support arm having the fishline guide portion and on the side of the bail 
when set in the fishline winding position is thin-walled. 
As the rotor (2) rotates, the weight of the pair of bail support arms (2f, 
2g) becomes applied eccentrically since the semi-annular bail arm (5) and 
the fishline guide portion (A) are made heavier, but the rotational 
balance of the rotor (2) is kept intact broken by offsetting the pair of 
bail support arms from the center of the rotary shaft of the rotor to the 
fishline playing-out side of the bail and by forming the rear portion of 
the rotor (2) such that a part of the rear portion on the side (.beta.) is 
made thin as a thin-walled portion (2k, 2p, 2r, 2s) as compared in 
configuration with the rear area (.alpha.) of the rotor facing the side 
(.beta.) across the rotary shaft (10). With the weight imbalance thus 
corrected, the rotational balance of the rotor 2 is stabilized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A description will subsequently be given of an embodiment of the present 
invention by reference to the accompanying drawings. FIGS. 1 to 6 
inclusive, illustrate a first embodiment: FIG. 1 is a sectional side view 
of the principal part of a spinning reel for fishing; FIG. 2 a plan view 
of a bail support arm on one side, a bail support member and a rotor; FIG. 
3 an elevational view of the spinning reel for fishing; FIG. 4 an 
elevational view of the bail support arm, the support member and the 
rotor; FIG. 5 a plan view of the bail support arm on the other side, the 
bail support member and the rotor; and FIG. 6 a sectional elevational view 
of the rotor taken on line B--B of FIG. 5. 
In a spinning reel for fishing, as shown in FIG. 1, a bearing 11 rotatably 
supports, in the forepart 1a of a reel body 1, the outer periphery of a 
cylindrical rotary shaft 10. A ratchet 13 and a collar 14 are fitted in 
front of the bearing 11 on the side of a spool 12. Finally the cylindrical 
portion 2a of a rotor 2 is fixed onto the shaft 10 with a locking nut 15. 
The rotor 2 is supported so that the rotation of the rotor 2 is interlocked 
with that of a handle 16 via a driving gear (not shown) meshing with a 
pinion (not shown) provided on the rotary shaft 10. 
The spool 12 is supported on the leading end portion of a spool shaft 17 
fitted into the rotary shaft 10 and projecting therefrom, the 
reciprocation of the spool 12 being interlocked with the rotation of the 
handle 16. 
As shown in FIGS. 1 to 6, the rotor 2 includes the cylindrical portion 2a, 
a front wall 2b, a large-diameter cylindrical portion 2c, and a pair of 
support arms 2f, 2g which projects forward from the outer periphery of the 
respective base portions 2d, 2e of the rotor 2. 
The pair of bail support arms 2f, 2g are formed so that they are deflected 
or offset from the rotary shaft center of the rotor 2 by a distance or 
dimension D toward the fishline playing-out side of the bail. 
One bail support member 3 having the fishline guide portion A is reversibly 
supported with a screw body 18 in the shaft portion 2h of the one support 
arm 2f. As shown in FIG. 2, the one bail support member 3 stays in the 
fishline winding position shown by a solid line when a fishline is wound 
up and is reversed toward the fishline playing-out position shown by a 
two-dot chain line when the fishline is played out. 
The other bail support member 4, opposite from the one bail support member 
3 having the fishline guide portion A, is reversibly supported with a 
screw body 19 in the shaft portion 2i of the other support arm 2g. As 
shown in FIG. 5, the other bail support member 4 stays in the fishline 
winding position shown by a solid line when the fishline is wound up and 
is reversed toward the fishline playing-out position shown by a two-dot 
chain line when the fishline is played out. 
The pair of support arms 2f, 2g are formed in such a configuration that, as 
shown in FIGS. 2 and 5, they are respectively deflected or slanted from 
the leading end portions to which the bail support members 3, 4 are fitted 
toward the base portions 2d, 2e on the side of a bail arm 5 in the 
fishline winding position shown by the solid line. 
Further, a recess 2j is formed in the inner periphery of the large-diameter 
cylindrical portion 2c and base portion 2e of the rotor 2 so that the rear 
portion of the inner periphery of the rotor 2 is formed into a thin-walled 
portion 2k at the area .beta. opposite with respect to the rotary shaft 10 
from the area .alpha. which is closer to the bail support arm 3 having the 
fishline guide portion A rather than the other bail support arm 4 and is 
located in the fishline winding side of the semi-annular bail arm 5. The 
portion of the rotor 2 within the area .beta. is suitable for reducing the 
of wall-thickness relative to the opposite area across the rotary shaft 
10. 
The recess 2j is formed axially rearwardly from the mid-point of the rotor 
2 to include the large-diameter cylindrical portion 2c and the base 
portion 2e up to the rear end thereof. 
A through-hole 2m directed toward the center of the rotor 2 is bored in the 
base portion 2d, in the one support arm 2f. 
Both ends of the semi-annular bail arm 5 are fitted to the respective bail 
support members 3, 4. 
The fishline guide roller 20 of the fishline guide portion A is provided 
between the bail support member 3 and the bail arm 5. 
Cover plates 21, 22 are fitted to the respective support arms 2f, 2g with 
machine screws 23, 24. 
An L-shaped lever 6 for reversing the bail support members 3, 4 and the 
bail arm 5 from the fishline playing-out position shown by the two-dot 
chain line to the fishline winding position shown by the solid line is 
mounted in the recess 2n of the one support arm 2f as shown in FIG. 1 and 
2. 
A projection 6a at one end of the lever 6 is fitted into a hole (not shown) 
of the bail support member 3, whereas the other end 6b thereof is formed 
downward and fitted into through-hole 2m. 
The other end 6b of the lever 6 faces a cam 1b provided on the reel body 1 
of FIG. 1 in such a manner that the end 6b is contactable with the cam 1b. 
When the rotor 2 is fitted to the rotary shaft 10, the pair of support arms 
2f, 2g are installed such that they are offset from the center of the 
rotary shaft to the fishline playing-out side of the bail so that the 
axial line passing through the centers of the screw bodies 18, 19 of one 
and the other bail support members 3, 4 is offset by the distance D with 
respect to the center of the rotary shaft 10. 
The operation of the spinning reel for fishing is such that when the hook 
and bait (not shown) are thrown out, the fishline (not shown) wound on the 
spool 12 is played out while the bail support members 3, 4 are in the 
fishline playing-out position shown by the two-dot chain line of FIGS. 2 
and 5. 
When the rotor 2 is rotated as the handle 16 is turned after the hook and 
bait are thrown out, the other end 6b of the lever 6 comes to contact the 
cam 1b provided on the reel body 1 and is moved back. Then the bail 
support member 3 is reversed and the bail support members 3, 4 together 
with the bail arm 5 are lifted up to the fishline winding position shown 
by the solid line of FIGS. 2 and 5. 
At this time, the fishline is picked up by the bail arm 5 and thereafter 
guided to the fishline guide roller 20 of the fishline guide portion A. 
When the rotor 2 is rotated as the handle 16 is turned, the fishline (not 
shown) is wound onto the spool 12. 
As the rotor 2 rotates, the weight of the pair of bail support arms 2f, 2g 
becomes applied eccentrically in general since the weight of the 
semi-annular bail arm 5 and the fishline guide portion A is applied to the 
bail support arms 2f, 2g. However, the rotational balance of the rotor 2 
can be ensured by mounting the pair of bail support arms offset from the 
center of the rotary shaft of the rotor 2 to the fishline playing-out side 
of the bail and by forming the rear portions of the inner periphery of the 
large-diameter cylindrical portion 2c and base portion 2e of the rotor 2 
on the .beta. side into the thin-walled portion 2k with the recess 2j as 
compared in configuration with the rear area .alpha. of the rotor without 
adding any balancer to the rear area .alpha.. The reduction in weight 
resulting from the thin-walled portion 2k formed on the .beta. side 
corrects the imbalance in weight between the bail support members 3, 4 and 
the imbalance in weight between the bail arm 5 and the opposed bail arm 
side. Thus the rotational balance of the rotor 2 is stabilized. 
With the rotor 2 whose rear portion is formed into the thin-walled portion 
2k with the recess 2j in the spinning reel for fishing arranged as 
described above, the imbalance in weight is thus corrected, whereby the 
stabilized rotational balance of the rotor 2 makes it possible to perform 
a comfortable winding operation without providing a balancer separately 
from the rotor. Therefore, the rotational balance of the rotor is 
stabilized without increasing the total weight of the reel or the number 
of parts. As a result both fishing operability, and also assembling 
efficiency are improved. 
Moreover, the rear end portion of the rotor without such an additional 
balancer can be configured without restrictions since no projections are 
needed. 
FIG. 7 is a sectional elevational view of a rotor as a second embodiment of 
the present invention. 
According to the second embodiment of the present invention, the outer 
peripheral diameter of the large-diameter cylindrical portion 2c of the 
rotor 2 is set greater and deflected so as to provide an indented portion 
2o on the .beta. side which is suitable for reduction of the wall 
thickness. The .beta. side is opposite across the rotary shaft 10 from the 
rear area .alpha. of the rotor which is closer to the bail support arm 3 
having the fishline guide portion A than to the opposite bail support arm 
4 and which is within the fishline winding side of the semi-annular bail 
arm 5. Thus the rear configuration is formed into a thin-walled portion 2p 
with the effect of correcting any imbalance in weight. 
The remaining arrangement is substantially similar to what has been 
described according to the first embodiment of the present invention. 
FIGS. 8 and 9 are, respectively a sectional elevational view and a side 
view of a rotor as a third embodiment of the present invention. 
According to the third embodiment of the invention, the base 2e of the bail 
support arm 2gof the rotor 2 on the .beta. side is partially indented to 
provide an indented portion 2q as shown by a hatch marks to form the rear 
portion of the rotor 2 axially into a thin-walled portion 2r and radially 
into a thin-walled portion 2s as compared in configuration with the rear 
area .alpha. of the rotor. As described before, the rear area .alpha. is 
on the bail side of the semi-annular bail arm 5 in the fishline winding 
setting and is closer to the bail support arm 3 having the fishline guide 
portion A than to the bail support arm 4 having no fishline guide. Thus 
the imbalance in weight is corrected. 
As shown by the two-dot chain lines of FIGS. 8 and 9, a recess may be 
formed in the outer periphery of the large-diameter cylindrical portion 2c 
of the rotor 2. 
The remaining arrangement is substantially similar to what has been 
described according to the first embodiment of the present invention. 
As set forth above, according to the present invention thus arranged, the 
rotational balance of the rotor is stabilized and a comfortable winding 
operation is obtained as the rear portion of the rotor is formed into the 
thin-walled portion so as to correct the weight imbalance. Further, the 
rotational balance of the rotor is stabilized and the fishing operability 
is improved without increasing the weight of the reel overall or and the 
number of parts as required since the balancer as a separate body can be 
dispensed with. 
It is thus possible to provide a spinning reel for fishing having an 
excellent effect of eliminating restrictions on configuration, since the 
rear end portion of the rotor without such a balancer is freed from the 
need for any projection.