Asymmetric oscillation mechanism for a spinning reel

There is hereinafter provided a reciprocating/oscillating structure for use in a fishing reel, wherein the guide carries a guide slot within it that is asymmetric in shape, and that creates two separate spool movement velocity regimes as the spool is moved forward and backward during recall of fishing line into the reel. The guide slot of the instant invention is asymmetrically constructed to produce, in a two-cycle-type spool movement arrangement, one spool velocity profile in the forward direction and a different spool velocity function in the rearward direction. In the preferred embodiment, the two velocity profiles (asymmetries of the guide) will be chosen to be complementary in the sense that imperfections in the velocity function in one direction can be compensated for to some extent during movement in the second cycle.

FIELD OF THE INVENTION
 This invention relates generally to fishing reels and, more particularly,
 to an improved oscillation mechanism for use when fishing line is drawn
 into a reel.
 BACKGROUND OF THE INVENTION
 From a user perspective, fishing reels are devices for distributing fishing
 line during a cast and winding it up again when the bait is retrieved.
 During normal operations, a fisherman ties some sort of object (e.g., a
 fishing lure) to one end of a long continuous piece of fishing line, the
 other end of which is secured to the reel's spindle or spool. The excess
 fishing line is wrapped about this same spool. Then, the selected object
 and the line attached thereto are cast into the water, with line from
 within the reel being smoothly released from the reel so as to impede as
 little as possible the flight of the cast object. The line is then
 recalled back to the reel through the use of a handle or crank, thereby
 winding it once again about the spool. Of course, in the preferred
 scenario a fish will be attached to the remote end of the line when it is
 so-recalled.
 It is the recall of line to the reel and the associated rewinding of it
 onto the spool which is the subject matter of the instant disclosure. More
 particularly, when line is retrieved, care must be taken to distribute it
 on the spool in such as manner as to insure that it can be extracted
 smoothly again at the next cast, thereby insuring that the next cast is as
 long as is possible under the circumstances.
 In a typical spinning fishing reel arrangement, when the crank is turned to
 recall the fishing line back to the reel, oscillatory longitudinal
 movement is imparted to the spool in a direction substantially traverse to
 the direction from which line enters the spool (i.e., parallel to the
 longitudinal axis of the spool, the "longitudinal" direction, hereinafter)
 so as to distribute the line more uniformly along the length of the spool.
 The spool's oscillatory motion is typically created as follows. Rotation
 of the crank turns a drive gear that contains a protrusion or pin on its
 face. The pin engages a guide slot that is cut into a slider-type guide,
 which guide is mounted on a movable central shaft that is constrained so
 as to be movable only in the longitudinal direction. As the gear rotates,
 the pin does likewise, thereby imparting reciprocating movement to the
 guide as the pin traces a path through its slot. Movement of the guide is
 then translated to the shaft which, in turn, moves the spool.
 In other instances, the guide might take the form of a lever arm which is
 pivotably attached to the reel housing at one end, with the other end of
 the lever being free to move along with the pin. As the pin travels
 through the guide slot, it moves the lever arm which, in turn, imparts
 longitudinal motion to the spool. An example of this sort of guide may be
 found in Tipton et al., U.S. Pat. No. 5,143,318, the disclosure of which
 is incorporated herein by reference.
 It is well known that the shape of the guide slot substantially influences
 the resulting movement of the spool and, hence, the distribution pattern
 of line that is deposited thereon. Many sorts of guide shapes have been
 suggested, each of which has its own advantages and disadvantages. Early
 efforts focused on the use of a straight guide slot, but it has been
 determined that this shape tends to pile up line near the outer margins of
 the spool. Better results have been obtained using "shaped" guide slots,
 with the shape being selected to make the line distribution as uniform as
 possible across the width of the spool. Two examples of the sorts of
 patterns that others have tried with varying degrees of success include
 the "Z" pattern of Shibata (U.S. Pat. No. 5,921,489) and the "S" pattern
 of Baumgartner et al. (U.S. Pat. No. 5,350,131), the disclosures of which
 are incorporated herein by reference.
 However, a problem with conventional spinning style reels is that they are
 susceptible to having the line bury itself as it is retrieved, which can
 cause binding the next time the line is paid out, as during a cast. One
 explanation for this phenomena is that the same velocity function--as
 defined by the shape of the guide curve--controls the distribution of the
 line as it moves out and back again. In other words, the coils of line
 tend to wrap closely next to each other as the spool moves slowly in each
 direction. The result of this is that the overlying turns align with and
 tend to be guided into the gap between adjacent underlying turns, thus,
 causing the line to "bury" itself. Further, since the actual velocity
 imparted to the spool can never really be constant--which would be the
 ideal situation--imperfections in the velocity function will be reflected
 in imperfections in the distribution of line along the width of the spool.
 Still further, problems in the out-going spool velocity profile will be
 mirrored by the in-coming spool velocity.
 One solution to this problem, as suggested in Tipton et al., cited
 previously, is to place the guide slot within a lever arm that is mounted
 in such as way as to cause an asymmetric velocity profile, such that the
 time for the spool to pass through the out-going cycle is longer (or
 shorter) than the time required for the spool to pass through the
 in-coming portion of the cycle. This has the effect of causing the line
 turns laid in one part of the stroke cycle to be more closely spaced than
 those in the other part of the stroke cycle. However, this approach is
 limited to use on a lever-arm based mechanism: it does not generally
 address the underlying problem of uneven line distribution on any type of
 reel.
 Heretofore, as is well known in the fishing reel arts, there has been a
 need for an invention to address and solve the above-described problems.
 Accordingly, it should now be recognized, as was recognized by the present
 inventor, that there exists, and has existed for some time, a very real
 need for a device that would address and solve the above-described
 problems.
 Before proceeding to a description of the present invention, however, it
 should be noted and remembered that the description of the invention which
 follows, together with the accompanying drawings, should not be construed
 as limiting the invention to the examples (or preferred embodiments) shown
 and described. This is so because those skilled in the art to which the
 invention pertains will be able to devise other forms of this invention
 within the ambit of the appended claims.
 SUMMARY OF THE INVENTION
 There is hereinafter provided a reciprocating/oscillating structure (or
 "guide") for use in a fishing reel, wherein the guide carries a guide slot
 within that is asymmetric in shape, and that creates two separate spool
 movement velocity regimes as the spool is moved forward and backward
 during recall of fishing line into the reel. The guide slot of the instant
 invention is asymmetrically constructed to produce, in a two-cycle-type
 spool movement arrangement, one spool velocity profile in the forward
 (first cycle) direction and a different spool velocity function in the
 rearward (second cycle) direction, where forward and rearward are measured
 with respect to the rod tip and reel handle, respectively. In the
 preferred embodiment, the two velocity profiles (asymmetries of the guide)
 will be chosen to be complementary in the sense that imperfections in the
 spool movement in one direction can be at least partially compensated for
 during movement in the other direction.
 According to a first preferred embodiment of the instant invention, there
 is provided a slider-type guide with an asymmetric guide slot placed
 therein, which imposes different velocity functions on the movement of the
 spool during each portion of the oscillation cycle. In more particular,
 during the first (rearward) portion of the movement cycle, the pin is
 within a section of the guide slot that is substantially straight and
 oriented to be roughly transverse to the spool movement direction. During
 the second (forward) portion of its stroke cycle, the pin will travel
 through a curved section that is "C" shaped, with the concave portion of
 the "C" oriented to face the rear of the reel. These two portions of the
 guide slot are preferably smoothly connected by a linear ramp.
 According to another preferred embodiment, there is provided an asymmetric
 guide slot substantially as described above, but wherein the guide takes
 the form of a lever arm which is rotably affixed at one end to a
 stationary member within the reel and which is engaged at its other end
 with the central shaft. Thus, movement of the pin through the asymmetric
 slot results in a pivoting movement of the lever arm about its fixed end
 which, in turn, is communicated to the spool.
 Of course, there are many other variations of this concept that might be
 applied in practice. However, the broad approach suggested by the instant
 inventor is that the two halves of the guide slot should be chosen to be
 different from one another and, to the extent possible,
 complementary--velocity wise--to insure as the rewound fishing line be
 distributed as evenly as possible on the spool. That is, the spool motion
 in one direction is specifically selected so as to compensate for
 deficiencies (e.g., non-uniformities) of the spool motion in the other
 direction.
 While the instant invention will be described in connection with a
 preferred embodiment, it will be understood that it is not intended to
 limit the invention to that embodiment. On the contrary, it is intended to
 cover all alternatives, modifications and equivalents as may be included
 within the spirit and scope of the invention as defined by the appended
 claims.

DETAILED DESCRIPTION OF THE INVENTION
 General Background
 In FIGS. 1 and 2, a spinning style fishing reel 10 is shown, which reel 10
 is of the type suitable for incorporation of the present invention. The
 reel 10 consists of a fixed housing 12 with an integral mounting stem 14
 with a foot 16 thereon for attachment to a fishing rod (not shown).
 As is conventional for this sort of reel, a spool 18 is provided at the
 front of the reel 10 that holds a supply of fishing line. To effect
 wrapping of the line around the spool 18 during recall of the line, a
 rotor 20 is provided. The rotor 20 has diametrically opposed bail ears 22,
 24 which rotate about a longitudinal, fore and aft axis 26 of the reel 10,
 i.e., an axis generally parallel to the central shaft 72. This rotation is
 imparted by turning a conventional external crank handle 28 through a
 mechanism to be described in detail below.
 The bail ears 22, 24 cooperatively define a support for a pivotable bail
 assembly 29 consisting of spaced bail arms 30, 32 and a formed wire bail
 34 connecting therebetween. As the rotor 20 is operated, a line guide 36
 on the bail assembly 29 engages the line and wraps the line around the hub
 38 of the spool 18. Because the line guide 36 preferably has a fixed axial
 position with respect to the reel as it is operating, it is necessary to
 reciprocate/oscillate the spool 18 about the fore and aft reel axis 26 to
 cause an even distribution of line on the spool 18 during retrieval. This
 reciprocation/oscillation occurs cyclically, with a spool stroke between
 the position of FIG. 1, representing the forwardmost spool position, and
 the position of FIG. 2, representing the rearwardmost spool position.
 Broadly speaking, there are two sorts of spinning reels that would be
 appropriate for use with the instant invention. The first is a slider-type
 reciprocating/oscillating mechanism of FIGS. 1 and 2. The second sort of
 spinning reel is one that utilizes a lever arm to produce the
 reciprocating/oscillating motion of the spool. An example of this sort of
 reel may be found in U.S. Pat. No. 5,143,318, cited previously.
 Preferred Embodiments
 The instant invention is directed to a structure for asymmetrically
 reciprocating/oscillating the spool 18 during retrieval of fishing line,
 with the details of a preferred embodiment of that structure being shown
 in FIGS. 3 to 7. Operationally, and as is well known to those of ordinary
 skill in the art, within a typical fishing reel 10 rotation of the rotor
 20 is effected by turning the reel crank handle 28, the rotational force
 of which is preferably communicated by way of a crank shaft 62 to a face
 gear 66 inside of the reel body, which engages a pinion gear 56 which
 fixedly surrounds a hollow tubular shaft, 50 so that rotation of the face
 gear 66 causes rotation of the tubular shaft 50. In the preferred
 embodiment, the tubular shaft 50 is journalled for rotation at its forward
 end (the end nearest the spool 38) by a plurality of bearings (not shown).
 The tubular shaft 50 at the end nearest the front of the reel 10 is
 fixedly connected to the hub of the rotor 20, so that rotation of the
 tubular shaft 50 is thereby communicated to the rotor 20.
 At the same time that the rotor 20 is operated by the crank handle 28, the
 spool 18 is caused to reciprocate in the line of the longitudinal reel
 axis 26. This reciprocating/oscillating movement of the spool 18 is
 permitted by mounting the spool 18 on a reciprocating/oscillating center
 shaft 72, which is coaxial with the tubular shaft 50 and is closely
 received within a bore extending axially therethrough for guided movement
 in the fore and aft directions.
 Fore and aft axial shifting of the center shaft 72 is accomplished through
 the oscillating oscillation/drive gear 88 in combination with guide 42. As
 can be more clearly seen in FIG. 3, the guide 42 roughly takes the form of
 an elongate rectangle in which a slot 96 has been incised. Obviously, the
 external dimensions of the guide 42 are unimportant for purposes of the
 instant invention, and its overall shape may be modified to suit the space
 requirements within a particular reel 10. It must be at least large enough
 to encompass the chosen guide slot 96, though.
 A pin 94 on the drive gear 88 engages the slot 96 and travels through that
 slot 96 as the drive gear 88 rotates. The guide 42 is preferably affixed
 to (or engaged with) center shaft 72 and the rotational movement drive of
 gear 88 moves the pin 94 through the guide slot 96 and causes a
 corresponding fore and aft movement of the guide 42 which, in turn, is
 communicated to the center shaft 72 and on, ultimately, to the line spool
 18.
 According to a first preferred embodiment of the instant invention and as
 is illustrated in FIG. 7, the guide structure 42 preferably takes the form
 of a "slider" as that term is known to those skilled in the art. Sliders
 are so-called because they "slide" forward and backward along the reel
 axis 26 in response to rotation of the drive gear 88, thereby driving
 oscillatory longitudinal motion of the rotor 20. Incised within the slider
 42 on the side facing the drive gear 88 is a preferably blind asymmetric
 slot 96 which is engaged with pin 94 on the face of the drive gear 88 so
 that rotation of the drive gear 88 is communicated to the guide structure
 42 and on ultimately to the spool 38.
 As can be seen more clearly in FIG. 7, the guide slot 96 of the preferred
 embodiment consists of two distinct regimes--a substantially straight
 upper terminus 200 and a curved lower terminus 220--separated by an
 optional transition region 210, where the terms "upper" and "lower" are
 used for purposes of specificity only, as the shapes of the two termini
 are obviously completely interchangeable. As is described later, it is
 critical for purposes of the instant invention that the upper terminus 200
 and lower terminus 220 be differently shaped, with the preferred shapes
 having been selected so as yield velocity profiles that are complimentary
 with each other. Said another way, the guide slot 96 consist of two
 asymmetric halves, where its asymmetry is measured with respect to its
 center line 280. It is preferable that the guide slot 96 be oriented so as
 to be substantially transverse to the direction of motion of the center
 shaft 72, i.e., its center line 285 should be at least approximately
 perpendicular to the longitudinal axis of the reel 10. That being said,
 the instant inventor has specifically contemplated that guide slot 96
 might be mounted at other angles with respect to the longitudinal axis.
 This sort of arrangement is well known to those of ordinary skill in the
 art.
 The transition region 210 is defined to be a central region of the guide
 slot 96 and is generally located between the positions of the pin 94 when
 the spool 38 reverses its movement direction. This may be seen most
 clearly by comparing FIGS. 1 and 2. In FIG. 1, the spool 38 is pictured as
 being proximate to its most extended position. The position of the pin 94
 when the spool 38 is in this position broadly defines the uppermost extent
 of the transition region 200 of the guide slot 96. In FIG. 2, the spool 38
 is pictured as being at nearly its most rearwardly retracted position and
 the pin 94 location in this figure broadly represents the lowermost extent
 of the transition region 210. The function of the transition region 210 is
 to smoothly link the two different shapes of the slot termini 200 and 220.
 That being said, it should be clear to one of ordinary skill in the art
 that transition region 210 is an integral part of the guide slot 96 and
 has only been introduced for convenience in describing the asymmetries of
 the termini of the slot 96. Further, although transition region 200 is
 shown as being roughly linear, that is only a preferred shape and it might
 be made to be curved or otherwise formed to suit the needs of a given
 reel.
 As is illustrated in FIGS. 8, 9, and 10, the shape of the guide slot 96 at
 its termini largely controls the pattern of line distribution in the
 center of the spool 38. FIG. 8 contains a series of "snapshots" showing
 the position of the guide slot 96/pin 94 combination at different points
 during in the rotation of the drive gear 88. More particularly, points A
 through F of FIG. 8 are separated by equal rotation angles of about
 30.degree. while the pin 94 is within the lower terminus 220 of the guide
 slot 96. If the guide slot 96 corrected perfectly for the circular motion
 of the drive gear 88, fishing line would be laid into spool 38 at equally
 spaced intervals. However, the corresponding line lay locations (A though
 F of FIG. 10, corresponding to slot 96 positions A through F of FIG. 8)
 are not equally spaced--compare the B-C and D-E separations of FIG. 10.
 However, note that on the reverse pass of the line guide 36, i.e., during
 the time that the pin 94 is within the upper terminus 200 of the slot 96
 (FIG. 9, L though G) the line also is laid at unequally spaced intervals,
 but the intervals G to L tend to alternate with the lay locations of the
 other terminus 220, A to F. Note, for example, that lay positions B and C
 of FIG. 10 tend to "fill in" between the larger gap K to J (similarly with
 D, I, H, and E). The net effect is to fill the spool 38 more evenly than
 the pattern of either terminus--operating in duplicate--would tend to do.
 Finally, it should be noted that the instant inventor has specifically
 contemplated that the asymmetric guide slot of the instant invention could
 be used in any type of fishing reel that utilizes a guide slot. For
 example, in another preferred embodiment, there is provided a guide and
 guide slot for a fishing reel substantially similar to that discussed
 previously, only wherein the guide slot is positioned on a lever arm,
 rather than on a slider. An example of this general sort of configuration,
 albeit with a symmetric guide slot, may be found in U.S. Pat. No.
 5,143,318, cited previously and incorporated herein by reference. It
 should be clear to one of ordinary skill in the art how the guide slot of
 the instant invention could be fashioned to operate on the lever of the
 cited patent.
 While the inventive device has been described and illustrated herein by
 reference to certain preferred embodiments in relation to the drawings
 attached hereto, various changes and further modifications, apart from
 those shown or suggested herein, may be made therein by those skilled in
 the art, without departing from the spirit of the inventive concept, the
 scope of which is to be determined by the following claims.