CLIAMS:We claim:

1. An unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force, the unwinding assisting device comprising:
a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion, and that moves toward a first side in an axial direction of the yarn supplying bobbin with the advancement of the unwinding of the yarn from the yarn supplying bobbin,
wherein the open portion is more proximally positioned on the first side than the constricted portion, and the position of the open portion with respect to the constricted portion is unchanged during unwinding, and
the inner diameter of at least an end of the open portion on the first side is constant.

2. The unwinding assisting device according to Claim 1, wherein the constricted portion is arranged extending from an end of the regulating member on a second side, which is opposite to the first side, up to a mid portion of the regulating member.

3. The unwinding assisting device according to Claim 1, wherein the constricted portion is arranged in a mid portion of the regulating member.

4. The unwinding assisting device according to Claim 2 or 3 wherein, a cross-sectional shape of an inner peripheral surface of the constricted portion cut along an axial direction of the regulating member is a straight line, and
a step or a taper with an increasing diameter toward the first side is formed at a boundary between the constricted portion and the open portion.

5. The unwinding assisting device according to Claim 4, wherein an inner diameter of the constricted portion is constant.

6. The unwinding assisting device according to Claim 2 or 3 wherein, a cross-sectional shape of an inner peripheral surface of the constricted portion cut along an axial direction of the regulating member is a curved line.

7. The unwinding assisting device according to any one of Claims 1 to 6, wherein an inner diameter of the open portion is constant.

8. The unwinding assisting device according to Claim 3, wherein the constricted portion is a projection that juts inward in a radial direction of the regulating member.

9. The unwinding assisting device according to Claim 8, wherein the inner diameter of the open portion is constant, and
an inner diameter of a portion toward the second side from the projection is equal to the inner diameter of the open portion and is constant, the second side being opposite to the first side.

10. The unwinding assisting device according to any one of Claims 1 to 9, wherein an umbrella section with an increasing inner diameter toward the first side is more proximally positioned on the first side than the open portion.

11. An unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force, the unwinding assisting device comprising:
a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion,
wherein the open portion is more proximally positioned on a first side in an axial direction of the regulating member than the constricted portion,
an inner diameter of the constricted portion is in the range of 20 mm to 29 mm, and
a difference between the inner diameter of the constricted portion and the inner diameter of the open portion is equal to or greater than 0.5 mm.

12. An unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force, the unwinding assisting device comprising:
a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion,
wherein the open portion is more proximally positioned on a first side in an axial direction of the regulating member than the constricted portion, and
an inner diameter of the constricted portion is of a value that allows a gap of 1 mm between an inner peripheral surface of the constricted portion and an outer peripheral surface of the yarn supplying bobbin placed inside the constricted portion.

13. An automatic winder comprising:
the unwinding assisting device according to any one of Claims 1 to 12; and
a bobbin supporting section that supports the yarn supplying bobbin.

14. The automatic winder according to Claim 13, further comprising an adjusting section that adjusts a position or an orientation of the yarn supplying bobbin with respect to the regulating member during unwinding.
,TagSPECI:BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates mainly to an unwinding assisting device that assists in unwinding a yarn from a yarn supplying bobbin.

2. Description of the Related Art
Automatic winders (yarn winding apparatuses) that wind a yarn that is unwound from a yarn supplying bobbin on a winding bobbin to form a package are known in the art. To obtain a satisfactory package, a shape, position, size, etc., of an unwinding assisting device that is arranged above the yarn supplying bobbin and that guides and adjusts a tension of the yarn being unwound from the yarn supplying bobbin are important.
Japanese Patent Application Laid-open No. H5-8939 and Japanese Unexamined Utility Model (Registration) Application Publication No. 2589527 disclose an unwinding assisting device that can be used in automatic winders.
The unwinding assisting device disclosed in Japanese Patent Application Laid-open No. H5-8939 includes a first balloon regulating member and a second balloon regulating member. The first balloon regulating member is positioned between the yarn supplying bobbin and the second balloon regulating member during the unwinding of the yarn from the yarn supplying bobbin. The first balloon regulating member descends with the advancement of the unwinding of the yarn from the yarn supplying bobbin, and thereby a fixed positional relationship is maintained between the unwinding assisting device and the yarn supplying bobbin.
The unwinding assisting device disclosed in Japanese Unexamined Utility Model (Registration) Application Publication No. 2589527 includes an umbrella section on a bottom end of the unwinding assisting device. The umbrella section covers a chase portion of the yarn supplying bobbin. The umbrella section prevents a balloon from expanding too much, and thereby suppresses an increase in a tension.
As the unwinding of the yarn from the yarn supplying bobbin advances and the amount of the yarn on the yarn supplying bobbin decreases to, for example, 30% of a fully wound amount (when the amount of the yarn remaining on the yarn supplying bobbin is 30% of a fully wound amount), as shown in FIG. 6A, the chase portion of the yarn layer of the yarn supplying bobbin is lost. As a result, a longer portion of the yarn being unwound from the yarn supplying bobbin rubs against the yarn layer of the yarn supplying bobbin (a portion enclosed within a broken line in FIG. 6A), leading to an increase in the tension and resulting in yarn breakage and sloughing (a phenomenon where several coils of the yarn come off at once from the yarn supplying bobbin). However, reducing the unwinding speed to prevent yarn breakage and sloughing undesirably decreases a winding efficiency.
Japanese Patent Application Laid-open No. H5-8939 discloses a technology whereby a tension is reduced by bringing the first balloon regulating member closer to the yarn supplying bobbin. However, a tension when the amount of the yarn remaining on the yarn supplying bobbin is equal to or less than 30% of the fully wound amount cannot be properly reduced by simply bringing the first balloon regulating member closer to the yarn supplying bobbin.
Japanese Unexamined Utility Model (Registration) Application Publication No. 2589527 discloses a technology whereby an umbrella section is used to suppress an increase in the tension. However, even this method is not capable of properly reducing the tension when the amount of the yarn remaining on the yarn supplying bobbin is equal to or less than 30% of the fully wound amount.

SUMMARY OF THE INVENTION
It is an object of the present invention to provide an unwinding assisting device capable of suppressing an increase in a tension that occurs at advanced stages of the unwinding of a yarn from a yarn supplying bobbin.
The means to solve the above problem and the advantage of the present invention are explained below.
According to an aspect of the present invention, there is provided an unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force. The unwinding assisting device includes a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion, and that moves toward a first side in an axial direction of the yarn supplying bobbin with the advancement of the unwinding of the yarn from the yarn supplying bobbin. The open portion is more proximally positioned on the first side than the constricted portion, and the position of the open portion with respect to the constricted portion is unchanged during unwinding. The inner diameter of at least an end of the open portion on the first side is constant.
According to another aspect of the present invention, there is provided an unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force. The unwinding assisting device includes a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion. The open portion is more proximally positioned on a first side in an axial direction of the regulating member than the constricted portion. An inner diameter of the constricted portion is in the range of 20 mm to 29 mm. A difference between the inner diameters of the constricted portion and the open portion is equal to or greater than 0.5 mm.
According to still another aspect of the present invention, there is provided an unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force. The unwinding assisting device includes a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion. The open portion is more proximally positioned on a first side in an axial direction of the regulating member than the constricted portion. An inner diameter of the constricted portion is of a value that allows a gap of 1 mm between an inner peripheral surface of the constricted portion and an outer peripheral surface of the yarn supplying bobbin placed inside the constricted portion.
According to still another aspect of the present invention, there is provided an automatic winder including the above unwinding assisting device and a bobbin supporting section that supports the yarn supplying bobbin.
The above and other objects, features, advantages and the technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of an overall structure of an automatic winder according to an embodiment of the present invention;
FIG. 2 is a schematic side view of a winder unit according to the present embodiment;
FIG. 3 is a perspective view of an unwinding assisting device according to the present embodiment;
FIG. 4A is a side view depicting a position adjustment of a yarn supplying bobbin according to the present embodiment;
FIG. 4B is a side view depicting the position adjustment of the yarn supplying bobbin according to the present embodiment;
FIG. 5A is a side view depicting the position adjustment of the yarn supplying bobbin according to the present embodiment;
FIG. 5B is a side view depicting the position adjustment of the yarn supplying bobbin according to the present embodiment;
FIG. 6A is a drawing depicting a shape of a balloon when an amount of yarn remaining on the yarn supplying bobbin is equal to or less than 30% of a fully wound amount in a conventional configuration;
FIG. 6B is a drawing depicting the shape of the balloon when the amount of the yarn remaining on the yarn supplying bobbin is equal to or less than 30% of the fully wound amount according to the present embodiment;
FIG. 7 is a graph showing a comparison of tensions when a conventional regulating member is used and when a regulating member according to the present embodiment is used;
FIG. 8A is a drawing of the regulating member according to the present embodiment;
FIG. 8B is a drawing of a modification of the regulating member according to the present embodiment;
FIG. 8C is a drawing of another modification of the regulating member according to the present embodiment;
FIG. 8D is a drawing of still another modification of the regulating member according to the present embodiment;
FIG. 9A is a drawing of a modification of the regulating member according to the present embodiment;
FIG. 9B is a drawing of another modification of the regulating member according to the present embodiment;
FIG. 9C is a drawing of still another modification of the regulating member according to the present embodiment;
FIG. 9D is a drawing of still another modification of the regulating member according to the present embodiment;
FIG. 10A is a side view depicting the position adjustment of the yarn supplying bobbin of a magazine-type automatic winder according to another embodiment of the present embodiment;
FIG. 10B is a side view depicting the position adjustment of the yarn supplying bobbin of a magazine-type automatic winder according to another embodiment of the present invention;
FIG. 11A is a side view depicting the position adjustment of the yarn supplying bobbin of a magazine-type automatic winder according to another embodiment of the present invention; and
FIG. 11B is a side view depicting the position adjustment of the yarn supplying bobbin of a magazine-type automatic winder according to another embodiment of the present invention.

DETAILED DESCRIPTION
Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings. First, an overview of an automatic winder 1 according to an embodiment of the present invention is explained. FIG. 1 is an elevation view of the automatic winder 1 according to the present embodiment. In the following explanation, the terms "top" and "bottom" denote positional relationship and are used for convenience and do not indicate the up and down directions of the proper vertical direction. Furthermore, the terms "top" and "bottom" correspond to a downstream side and an upstream side of a running direction of a yarn 20 as well as to a "second side" and a "first side" of a yarn supplying bobbin 21 and a regulating member 72 in an axial direction of the yarn supplying bobbin 21 and the regulating member 72.
The automatic winder 1 according to the present embodiment includes a plurality of winder units 4 arranged side by side, and a machine control device 7 arranged at one end in a direction in which the winder units 4 are arranged.
The machine control device 7 is capable of communicating with the winder units 4, and performs centralized management of operations of the winder units 4. The machine control device 7 includes a machine input section 8 that can be used to perform various settings (input of a type of the yarn supplying bobbin 21, etc., used in a winding operation of each winder unit 4) on each winder unit 4, and a machine display section 9 capable of displaying a state, etc., of the winding operation of each winder unit 4.
The winder unit 4 is explained in detail below with reference to FIG. 2. FIG. 2 is a schematic side view of the winder unit 4. The winder unit 4 winds the yarn 20 unwound from the yarn supplying bobbin 21 on a winding bobbin 22 to form a package 29. The component parts of the winder unit 4 are explained below.
The automatic winder 1 according to the present embodiment includes a not shown conveying-tray type bobbin delivering device. The automatic winder 1 includes a not shown bobbin transportation guide path constituted by a conveyor belt. A conveying tray (bobbin supporting section) 80 that carries thereon the yarn supplying bobbin 21 moves along the bobbin transportation guide path to deliver the yarn supplying bobbin 21 to the winder unit 4.
A yarn supplying section 10 of the automatic winder 1 according to the present embodiment includes the conveying tray 80 and a position adjusting section (adjusting section) 81 (see FIGS. 4A to 5B) capable of adjusting the position of the conveying tray 80. How the position adjusting section 81 adjusts the position of the conveying tray 80 (that is, the position of the yarn supplying bobbin 21) is explained later.
A winding section 16 unwinds the yarn 20 from the yarn supplying bobbin 21 whose position has been adjusted by the position adjusting section 81. As shown in FIG. 2, the winder unit 4 mainly includes an unwinding assisting device 12, a tension applying device 13, a yarn joining device 14, and a yarn monitoring device 15 arranged in the mentioned order on a yarn running path in a direction from the yarn supplying section 10 toward the package 29.
As shown in FIG. 3, the unwinding assisting device 12 includes a fixed member 71, the regulating member 72, an ascending and descending member 73, and a chase portion detection sensor 74.
The fixed member 71 is fixed to a unit frame via a suitable member. The regulating member 72 is cylindrical and is arranged so as to cover the outer side of the fixed member 71.
The ascending and descending member 73 is movable in the vertical direction (axial direction of the yarn supplying bobbin 21 and the regulating member 72) integrally with the regulating member 72. The chase portion detection sensor 74 that detects a chase portion 21a of the yarn supplying bobbin 21 is mounted on the ascending and descending member 73.
With such a configuration, the ascending and descending member 73 is caused to descend based on a detection signal output by the chase portion detection sensor 74, and thereby the regulating member 72 can be positioned at a predetermined distance from the chase portion 21a. Furthermore, a constant distance can be maintained between the chase portion 21a and the regulating member 72 by causing the ascending and descending member 73 to descend with the descent of the position of the chase portion 21a with the advancement of the unwinding of the yarn 20 from the yarn supplying bobbin 21. In this manner, a balloon that is formed at the position where the yarn 20 separates from the chase portion 21a during the unwinding of the yarn 20 from the yarn supplying bobbin 21 can be properly regulated, and the winding operation can be performed while maintaining a constant tension on the yarn 20 being unwound from the yarn supplying bobbin 21.
In the present embodiment, when an amount of the yarn 20 remaining on the yarn supplying bobbin 21 decreases (for example, to an amount equal to or less than 30% of a fully wound amount), an increase in the tension on the yarn 20 can be suppressed by contriving an inner shape of the regulating member 72. The inner shapes of the regulating member 72 and their functions, etc., are explained later.
The tension applying device 13 shown in FIG. 2 applies a predetermined tension on the running yarn 20. The tension applying device 13 according to the present embodiment has a gate-type structure with movable comb teeth arranged with respect to fixed comb teeth. The movable comb teeth are rotatable by a rotary solenoid so that the movable comb teeth and the fixed comb teeth are in an engaged state or a released state.
A lower-yarn detection sensor 31 is arranged between the unwinding assisting device 12 and the tension applying device 13. The lower-yarn detection sensor 31 detects whether the yarn 20 is running at the position where the lower-yarn detection sensor 31 is arranged.
The yarn monitoring device 15 monitors a thickness, etc., of the yarn 20 to detect yarn defects, such as a slub. A cutter 39 that cuts the yarn 20 immediately upon detection of a yarn defect by the yarn monitoring device 15 is arranged further upstream on a yarn route than the yarn monitoring device 15 (below the yarn monitoring device 15).
The yarn joining device 14 joins a lower yarn from the yarn supplying bobbin 21 and an upper yarn from the package 29 when the yarn 20 is cut by the cutter 39 upon detection of a yarn defect by the yarn monitoring device 15 or when a yarn breakage occurs during unwinding of the yarn 20 from the yarn supplying bobbin 21, or upon replacement of the yarn supplying bobbin 21. The yarn joining device 14 can be a type that uses a fluid, such as compressed air, or can be a mechanical type.
A lower-yarn guiding pipe 25 that catches and guides the lower yarn from the yarn supplying bobbin 21 and an upper-yarn guiding pipe 26 that catches and guides the upper yarn from the package 29 are arranged near the yarn joining device 14. A suction hole 32 is formed at the tip of the lower-yarn guiding pipe 25 and a suction mouth 34 is formed at the tip of the upper-yarn guiding pipe 26. The lower-yarn guiding pipe 25 and the upper-yarn guiding pipe 26 are, respectively, connected to an appropriate negative pressure source to cause the suction hole 32 and the suction mouth 34 to produce suction force.
With such a configuration, during yarn breakage, etc., the suction hole 32 of the lower-yarn guiding pipe 25 is turned downward about a shaft 33 to suck and catch the lower yarn. Thereafter, the lower-yarn guiding pipe 25 is turned upward to guide the lower yarn up to the yarn joining device 14. Substantially simultaneously with the above action, the upper-yarn guiding pipe 26 is turned upward about a shaft 35 from the position shown in FIG. 2 and also the package 29 is reversely rotated to enable the suction mouth 34 to catch the upper yarn unwound from the package 29. Thereafter, the upper-yarn guiding pipe 26 is turned downward about the shaft 35 to guide the upper yarn to the yarn joining device 14. Yarn joining of the lower yarn and the upper yarn is then carried out by the yarn joining device 14.
The winder unit 4 also includes a cradle 23 and a traverse drum 24 further downstream of the yarn monitoring device 15. The cradle 23 is configured to enable attachment of the winding bobbin 22 thereto. The traverse drum 24 traverses the yarn 20 through a traverse groove formed on the surface thereof and also drives the winding bobbin 22 to wind the yarn 20.
With such a configuration, each winder unit 4 of the automatic winder 1 winds the yarn 20 that is unwound from the yarn supplying bobbin 21 on the winding bobbin 22 to form the package 29 of a predetermined length.
How the position adjusting section 81 adjusts the position of the yarn supplying bobbin 21 is explained next. When the yarn supplying bobbin 21 is not slanting, the position adjusting section 81 aligns the axial line of the yarn supplying bobbin 21 and the axial line of the regulating member 72 by aligning the conveying tray 80 exactly below the regulating member 72 of the unwinding assisting device 12.
However, when the yarn supplying bobbin 21 is slanting with respect to the conveying tray 80 (as shown in FIG. 4A), even if the conveying tray 80 is aligned exactly below the regulating member 72, the position of the yarn supplying bobbin 21 cannot be stabilized. Hence, the position adjusting section 81 adjusts the position of the yarn supplying bobbin 21 such that the axial line of the regulating member 72 passes through the center of a core tube of the yarn supplying bobbin 21.
Specifically, the position adjusting section 81 first moves the conveying tray 80 toward the front side (toward the right in FIGS. 4A and 4B), and stops moving the conveying tray 80 when the center of the core tube of the yarn supplying bobbin 21 is detected by the chase portion detection sensor 74 (a state shown in FIG. 4B).
Thereafter, the position adjusting section 81 moves the conveying tray 80 back toward the rear side (toward the left in FIGS. 4A and 4B), and stops moving the conveying tray 80 when the core tube of the yarn supplying bobbin 21 is no longer detected by the chase portion detection sensor 74 (a state shown in FIG. 5A). Since the position of the chase portion detection sensor 74 is known, the conveying tray 80 can be aligned with the target position of the yarn supplying bobbin 21 by causing the conveying tray 80 to move from this position by a certain distance (a state shown in FIG. 5B).
How the inner shape of the regulating member 72 of the unwinding assisting device 12 reduces a tension during unwinding when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount is explained below.
FIG. 6A depicts the unwinding of a yarn in a conventional configuration when the amount of the yarn remaining on the yarn supplying bobbin is equal to or less than 30% of the fully wound amount. Because the chase portion 21a of the yarn supplying bobbin 21 is lost when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount, a longer portion of the yarn 20 (a portion enclosed within the broken line in FIG. 6A) rubs against the yarn layer). This leads to an increase in the tension, resulting in increased possibility of yarn breakage or sloughing.
In this respect, in the present embodiment, an inner diameter of the regulating member 72 is varied to suppress the increase in the tension during unwinding when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount. Specifically, as shown in FIG. 6B, the regulating member 72 of the present embodiment has an open portion (larger diameter portion) 72a and a constricted portion (smaller diameter portion) 72b. The open portion 72a has an inner diameter larger than the constricted portion 72b and is positioned below the constricted portion 72b.
In this manner, because the regulating member 72 has the constricted portion 72b, when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount, the constricted portion 72b comes into contact with the balloon and suppresses bulging of the balloon on the upper portion (see FIG. 6B). This causes the lower portion of the balloon to bulge out significantly. That is, an apex of the balloon is brought to a lower position. Consequently, the portion of the yarn 20 that rubs against the yarn layer (portion enclosed within a broken line in FIG. 6B) can be shortened. In this manner, the tension during unwinding when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount can be reduced.
FIG. 7 is a graph showing data obtained from an experiment in which a change in tension is measured for the duration of unwinding according to the present embodiment and according to the conventional configuration. It can be understood from the graph that, by arranging the constricted portion 72b and the open portion 72a inside the regulating member 72, as in the present embodiment, the tension during unwinding when there is less amount of the yarn 20 remaining on the yarn supplying bobbin 21 toward the end of unwinding period (when the amount of the yarn 20 remaining on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount) is reduced. Specifically, the result of the experiment reveals that, by adopting the configuration according to the present embodiment, the tension during unwinding in the present embodiment can be reduced by about 25% as compared to the conventional configuration.
By reducing the tension in this manner, a frequency of yarn breakage and sloughing can be reduced without having to slow down the winding speed. Consequently, a winding efficiency can be improved.
In the conventional configuration as well as the configuration according to the present embodiment, umbrella sections 72c and 172c are formed, respectively, on the bottom ends of the regulating members 72 and 172. An inner diameter of the umbrella sections 72c and 172c increases from top to bottom of the umbrella sections 72c and 172c. The umbrella section 72c is a member that prevents the balloon from expanding too much. The taper of the umbrella section 72c forms a relatively large angle with respect to the axial line of the regulating member 72. Consequently, unlike the open portion 72a of the present embodiment, the umbrella section 72c is unable to suppress the bulging in the upper portion of the balloon when the amount of the yarn 20 on the yarn supplying bobbin 21 is equal to or less than 30% of the fully wound amount. Hence, the umbrella section 72c is unable to suppress the increase in the tension due to rubbing of the yarn 20 against the yarn layer. It is preferable that the taper of the umbrella section 72c with respect to the axial line is, for example, 15 degrees. However, the angle is not limited to the value mentioned here.
Next, possible shape variations capable of demonstrating the desired advantage of the present invention are explained. FIGS. 8A to 8D are cross-sections of the regulating members 72 of various shapes, taken along the axial direction.
The regulating member 72 shown in FIG. 8A includes the open portion 72a, the constricted portion 72b, a step 72d that lies at the boundary between the open portion 72a and the constricted portion 72b, and the umbrella section 72c. In the regulating member 72 shown in FIG. 8B, a taper 72e is provided instead of the step 72d. The constricted portion 72b shown in FIGS. 8A and 8B extends from the top end up to the mid portion of the regulating member 72.
The regulating members 72 shown in FIGS. 8A and 8B can be formed, for example, by first separately creating the open portion 72a and the constricted portion 72b and thereafter joining the open portion 72a and the constricted portion 72b. The umbrella section 72c can be formed integrally with the regulating member 72 or formed separately and attached to the regulating member 72 later.
The regulating member 72 shown in FIG. 8C includes the open portion 72a, the constricted portion 72b, the umbrella section 72c, and a second open portion 72f. The constricted portion 72b shown in FIG. 8C is a projection that juts inward in a radial direction of the regulating member 72 and is formed only in the mid portion of the regulating member 72.
The regulating member 72 shown in FIG. 8C can be formed, for example, by pressing and deforming the mid portion of a cylindrical member. In the resulting shape, the inner diameter of the open portion 72a and the second open portion 72f will be the same.
The umbrella section 72c is not essential for demonstrating the desired advantage of the present invention, and can be omitted as shown in FIG. 8D.
Further shape variations of the regulating member 72 are shown in FIGS. 9A to 9D. The regulating members 72 shown in FIGS. 9A to 9D are obtained by partially modifying the regulating member 72 shown in FIG. 8A. However, similar modifications can also be made to the regulating members 72 shown in FIGS. 8B to 8D. Furthermore, multiple combinations of various features shown in FIGS. 9A to 9D can also be made.
As shown in FIG. 9A, the open portion 72a, the constricted portion 72b, and the umbrella section 72c can be integrated. The regulating member 72 having integrally molded open portion 72a, the constricted portion 72b, and the umbrella section 72c can be formed by using, for example, a die, etc.
FIG. 9B is a drawing of an example where the corner of the step 72d is rounded (curved). The position at which the angle can be rounded is arbitrary. For example, the end of the open portion 72a or the end of the constricted portion 72b in each of FIGS. 8A to 8D can be rounded. The corner can also be flattened (chamfered).
FIG. 9C is a drawing of an example where the constricted portion 72b has a curved edge instead of a straight edge.
FIG. 9D is a drawing of an example where the open portion 72a and the constricted portion 72b are slightly tapered. The tapering of the open portion 72a and the constricted portion 72b is made such that there is a slight increase in the inner diameters from top to bottom of the open portion 72a and the constricted portion 72b. Because the taper can also be used as a draft angle at the time of die casting, it is preferable that this shape variation shown in FIG. 9D is combined with the shape variation shown in FIG. 9A. Furthermore, because the taper in the open portion 72a forms a small angle with respect to the axial line of the regulating member 72, like the open portion 72a in other shape variations, this open portion 72a also demonstrates the desired advantage of being capable of suppressing the bulging in the upper portion of the balloon, and thereby reducing the tension. Hence, the open portion 72a and the umbrella section 72c shown in FIG. 9D completely differ in their shapes and functions from each other. Furthermore, in the present specification, even though a taper of a small angle is formed or a minute unevenness is formed in the open portion 72a or the constricted portion 72b, the open portion 72a or the constricted portion 72b shall be deemed to fall under "constant inner diameter". If it is taken into consideration that the taper can be used as a draft angle, it is preferable that the angle of the fine taper of the open portion 72a and the constricted portion 72b with respect to the axial line is, for example, 2 degrees. However, the angle is not limited to the value mentioned here. Any angle ranging from 0 degree to 5 degrees is permitted.
The inner diameters of the open portion 72a and the constricted portion 72b and the positions where the open portion 72a and the constricted portion 72b are formed can be selected as desired. For example, the inner diameter of the constricted portion 72b can range from 20 millimeter (mm) to 29 mm and a difference in the inner diameters of the constricted portion 72b and the open portion 72a can be kept as equal to or greater than 0.5 mm. For example, the inner diameter of the constricted portion 72b can be kept as 26 mm, and the inner diameter of the open portion 72a can be kept as 34 mm. It is preferable to set the position of the constricted portion 72b such that the boundary (for example, the step 72d) between the open portion 72a and the constricted portion 72b is about 50 mm from the top end of the regulating member 72. It is preferable that a gap between the constricted portion 72b and the core tube of the yarn supplying bobbin 21 is equal to or greater than 1 mm.
As explained above, the unwinding assisting device 12 according to the present embodiment includes the cylindrical regulating member 72. The regulating member 72 includes the constricted portion 72b and the open portion 72a having an inner diameter that is greater than that of the constricted portion 72b. The regulating member 72 moves closer to the yarn supplying bobbin 21 as the unwinding of the yarn 20 from the yarn supplying bobbin 21 advances (the regulating member 72 moves from an unwinding side of the yarn supplying bobbin 21, which is the 'second side' of the yarn supplying bobbin 21 in the axial direction, to a supported side of the yarn supplying bobbin 21, which is the 'first side' of the yarn supplying bobbin 21 in the axial direction). The open portion 72a is positioned below the constricted portion 72b and the position of the open portion 72a with respect to the constricted portion 72b is unchanged during unwinding. The inner diameter of at least the bottom end of the open portion 72a is constant.
To rephrase it from another perspective, the unwinding assisting device 12 includes the fixed member (fixed-type balloon regulating member) 71 that is substantially cylindrical and whose position is unchanged during unwinding and the regulating member (movable-type balloon regulating member) 72 that is substantially cylindrical and that is movable relative to the fixed member 71 and descends as the unwinding advances. The regulating member 72 includes the constricted portion (smaller diameter portion) 72b and the open portion (larger diameter portion) 72a that is positioned below the constricted portion 72b and has an inner diameter larger than the constricted portion 72b. When the regulating member 72 descends to a previously set lower limit position and the chase portion 21a of the yarn layer of the yarn supplying bobbin 21 is lost, the constricted portion 72b comes into contact with the balloon and shifts the apex of the balloon downward, thereby regulating the bulge in the upper portion of the balloon. The open portion 72a allows the lower portion of the balloon to bulge out. The position of the constricted portion 72b with respect to the open portion 72a is constant.
With the above configuration, the portion of the yarn 20 being unwound from the yarn supplying bobbin 21 that rubs against the yarn layer is shortened. Consequently, the tension on the yarn 20 can be reduced, and sloughing can be prevented. Hence, the frequency of yarn breakage can be reduced without having to slow down the winding speed. Consequently, the winding efficiency can be improved.
Another embodiment of the present invention is explained next. In the above embodiment, the present invention is applied to a tray-type automatic winder 1. In this embodiment, the present invention is applied to a magazine-type automatic winder. In this modification, an orientation alignment of the yarn supplying bobbin 21 is performed as explained below. Because it is a known method, only a simple explanation is provided.
In the magazine-type automatic winder 1, a yarn supplying bobbin guiding section 61 shown in FIG. 10A guides the yarn supplying bobbin 21, which is delivered by a not shown magazine, to the yarn supplying section 10. The yarn supplying section 10 includes an orientation adjusting section (bobbin supporting section and adjusting section) 11. The orientation adjusting section 11 adjusts an orientation of the yarn supplying bobbin 21 by turning a member inserted into the core tube of the yarn supplying bobbin 21 to front and rear sides.
How the orientation adjusting section 11 adjusts the orientation of the yarn supplying bobbin 21 is explained below. The orientation adjusting section 11 receives the yarn supplying bobbin 21 delivered by the yarn supplying bobbin guiding section 61 (a state shown in FIG. 10A), turns the yarn supplying bobbin 21 to the rear side, and causes the yarn supplying bobbin 21 to stand upright (a state shown in FIG. 10B).
Thereafter, the orientation adjusting section 11 once again slightly turns the yarn supplying bobbin 21 to the front side until the yarn supplying bobbin 21 is detected by the chase portion detection sensor 74 (a state shown in FIG. 11A). The automatic winder 1 has stored therein, by associating with a type, etc., of the yarn supplying bobbin 21 being used, information pertaining to by what angle the yarn supplying bobbin 21 is to be turned from a position where the chase portion detection sensor 74 starts detecting the yarn supplying bobbin 21 to bring the yarn supplying bobbin 21 to the proper position. The orientation adjusting section 11 accordingly turns the yarn supplying bobbin 21 by the amount corresponding to this previously set value (a state shown in FIG. 11B).
In the magazine-type automatic winder 1, the orientation of the yarn supplying bobbin 21 is adjusted as explained above. In this manner, the axial line of the yarn supplying bobbin 21 is aligned with the axial line of the unwinding assisting device 12 (regulating member 72).
Exemplary embodiments of the present invention are explained above; however, the following variations in the configuration can be made.
The component members constituting the unwinding assisting device 12 can be selected as desired. One or more between the fixed member 71, the regulating member 72, the ascending and descending member 73, and the chase portion detection sensor 74 can be omitted or their shapes can be changed. For example, the present invention can also be applied to a fixed-type unwinding assisting device that does not include the ascending and descending member 73.
The regulating member 72 can be of shapes other than the variations and the combinations thereof explained above. In the present specification, members having a slit and members whose cross-section does not have an accurate circular shape also shall be deemed to fall under "cylindrical shape". Hence, the fixed member 71 or the regulating member 72 can have a slit or cross-section of the fixed member 71 and the regulating member 72 can be non-circular.
The adjustment methods of the position (orientation) by the position adjusting section 81 and the orientation adjusting section 11 are only examples; other control methods can be adopted or other sensors, etc., can be used for performing position (orientation) adjustments.
The traverse device can be an arm-type or a drum-type traverse device instead of one having the traverse drum 24.
The setting angle at which the yarn supplying bobbin 21 can be selected as desired and is not limited to vertical direction (substantially vertical direction); the yarn supplying bobbin 21 can be arranged slantingly relative to the vertical direction. Because, as mentioned above, the terms "top" and "bottom" in the present specification are not limited to a perfect vertical direction, even a configuration where the yarn supplying bobbin 21 is arranged at a predetermined angle shall be deemed to fall under "automatic winder" of the present invention.
According to an aspect of the present invention, an unwinding assisting device that regulates a balloon, which is a portion of a yarn being unwound from a yarn supplying bobbin and that sways owing to the centrifugal force, has the following configuration. That is, the unwinding assisting device includes a regulating member. The regulating member is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion. The regulating member moves toward a first side in an axial direction of the yarn supplying bobbin with the advancement of the unwinding of the yarn from the yarn supplying bobbin. The open portion is more proximally positioned on the first side than the constricted portion, and the position of the open portion with respect to the constricted portion is unchanged during unwinding. The inner diameter of at least an end of the open portion on the first side is constant.
With this configuration, when the amount of the yarn remaining on the yarn supplying bobbin is equal to or less than 30% of the fully wound amount with the advancement of the unwinding of the yarn from the yarn supplying bobbin, an inner peripheral surface of the constricted portion comes into contact with the balloon, and thereby suppresses bulging of the balloon on an upper portion of the yarn supplying bobbin, and causes the lower portion of the balloon to bulge out significantly. Consequently, the portion of the yarn that rubs against the yarn layer can be shortened, a tension on the yarn can be reduced, and sloughing can be prevented. Therefore, a frequency of yarn breakage can be reduced without having to slow down a winding speed. Consequently, a winding efficiency can be improved.
In the above unwinding assisting device, it is preferable that the constricted portion extends from an end of the regulating member on a second side, which is opposite to the first side, up to a mid portion of the regulating member.
With this configuration, the constricted portion is arranged over a wider area, and therefore can cope with a variety of balloon conditions. This configuration also enables an apex of the balloon to easily come into contact with the inner peripheral surface of the constricted portion and facilitates suppressing of the bulging of the balloon on the upper portion. Furthermore, the regulating member can be easily made using a die, for example.
In the above unwinding assisting device, it is preferable that the constricted portion is arranged in a mid portion of the regulating member.
With this configuration, only a part of the regulating member needs to have a small diameter. Consequently, the range requiring machining (or the range where a member needs to be mounted) can be reduced, and thereby a manufacturing cost can be reduced.
It is preferable that the above unwinding assisting device has the following structure. That is, a cross-sectional shape of the inner peripheral surface of the constricted portion cut along an axial direction of the regulating member is a straight line. A step or a taper with an increasing diameter toward the first side is formed at a boundary between the constricted portion and the open portion.
In the above unwinding assisting device, an inner diameter of the constricted portion can be constant.
In the above unwinding assisting device, the cross-sectional shape of the inner peripheral surface of the constricted portion cut along the axial direction of the regulating member can be a curved line.
In the above unwinding assisting device, an inner diameter of the open portion can be constant.
The desired advantage of the present invention, which is the reduction of tension, is therefore realized by using the regulating member of various shapes described above.
In the above unwinding assisting device, it is preferable that the constricted portion has a projection that juts inward in a radial direction of the regulating member.
In the above unwinding assisting device, the inner diameter of the open portion is constant. An inner diameter of a portion toward the second side from the projection is equal to the inner diameter of the open portion and is constant.
With this configuration, by merely pressing a portion of a cylindrical member having a constant diameter, a regulating member capable of demonstrating the desired advantage, which is the reduction of tension, can be formed.
In the above unwinding assisting device, it is preferable that an umbrella section with an increasing inner diameter toward the first side be more proximally arranged on the first side than the open portion.
With this configuration, the expansion of the balloon can be suppressed from the start to the end of unwinding, and the tension can be reduced.
According to another aspect of the present invention, an unwinding assisting device includes a regulating member that is cylindrical, and includes a constricted portion and an open portion having an inner diameter larger than the constricted portion. The open portion is more proximally arranged on a first side than the constricted portion. An inner diameter of the constricted portion is in the range of 20 millimeter (mm) to 29 mm, and a difference between the inner diameters of the constricted portion and the open portion is equal to or greater than 0.5 mm.
According to still another aspect of the present invention, an inner diameter of the constricted portion is of a value that allows a gap of 1 mm between an inner peripheral surface of the constricted portion and an outer peripheral surface of the yarn supplying bobbin placed inside the constricted portion.
By above numerical limitation, an unwinding assisting device capable of effectively demonstrating the desired advantage of the present invention, which is the reduction of tension, can be realized.
The above unwinding assisting device is included in an automatic winder that also includes a bobbin supporting section that supports the yarn supplying bobbin.
With the above configuration, an automatic winder capable of effectively demonstrating the desired advantage of the present invention, which is the reduction of tension, can be realized.
It is preferable that the automatic winder includes an adjusting section that adjusts a position or an orientation of the yarn winding bobbin with respect to the regulating member during unwinding.
Generally, the smaller the inner diameter of the constricted portion, the better the tension can be reduced. However, the smaller the inner diameter of the constricted portion, the higher the possibility that the yarn supplying bobbin comes into contact with the constricted portion during unwinding. In this respect, because with the above configuration the positional relationship between the yarn supplying bobbin and the constricted portion can be adjusted appropriately by the adjusting section, the desired advantage of the present invention, which is the reduction of tension, can be effectively demonstrated.
Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching of the claims.