EP2006427A2

EP2006427A2 - Fiber bundle concentrating apparatus for spinning machine

Info

Publication number: EP2006427A2
Application number: EP08157271A
Authority: EP
Inventors: Naoki Maruyama; Koji Maeda; Kazuo Seiki
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2007-06-01
Filing date: 2008-05-30
Publication date: 2008-12-24
Also published as: JP2008297676A; EP2006427A3; CN101314875A

Abstract

A fiber bundle concentrating apparatus includes a guide member having a pair of guide surfaces which face each other and guide a fiber bundle so that the width of the fiber bundle is narrowed, and an excitation device for vibrating the guide member to generate sound pressure. The guide member includes a pair of guide portions which are placed to face each other, so that the guide surfaces are formed. Each guide portion has a straight portion and a tapered portion, which are made continuous by a connection portion. The straight portions are formed so that the distance between the two guide surfaces is constant, and the tapered portions are formed so that the distance between the two guide surfaces gradually becomes greater toward a direction opposite to the advancing direction of the fiber bundle. The straight portions form an outlet through which the fiber bundle is fed out from the guide member. The shape of the guide portions is set so that when the guide member is vibrated at a predetermined frequency by the excitation device, the outlet and the connection portions are located in locations different from the nodes of vibration.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a fiber bundle concentrating apparatus for a spinning machine, and in particular, to a fiber bundle concentrating apparatus which is placed downstream from the draft device (draft part) of a ring spinning machine and appropriate for concentrating a fiber bundle that has been drafted by the draft device.
Various types of fiber bundle concentrating apparatuses for concentrating a fiber bundle that has been drafted in advance, before twisting, for the purpose of gaining high quality thread having little unevenness and little fluff have been proposed for ring spinning machines. As a method for concentrating a fiber bundle, a method using a mechanical guide (collector), and a method for making an air flow for suction act on a fiber bundle moving on a perforated belt (ventilation apron) are generally used.
The guides and guide members, for example the perforated belt, which are used in these methods, guide the fiber bundle while contacting the fiber bundle. Measures for reducing friction on the surface of the guide member are necessary in order to guide the fiber bundle without disturbing fibers aligned in the fiber bundle, and it is necessary to prevent this effect of reducing friction from weakening over time. Japanese Laid-Open Patent Publication No. 2007-9391 discloses a fiber bundle guiding apparatus for guiding a fiber bundle without contacting the fiber bundle in order to prevent friction on the guide surface of the guide member. The fiber bundle guiding apparatus in this publication is provided with a guide member having a pair of guide surfaces for guiding the fiber bundle moving in an advancing direction in such a manner that the width of the fiber bundle becomes narrower, and an excitation device for vibrating the guide member so that sound pressure for preventing the fiber bundle from contacting the guide surfaces is generated. The excitation device vibrates the guide member at a predetermined resonant frequency (for example, approximately 34 kHz), and thus, the guide member guides the fiber bundle in a non-contact state.
In order to form high quality thread, which is referred to as compact thread, it is necessary to concentrate fiber bundle in such a manner that they have a width of approximately 0.5 mm to 1.0 mm in the fiber bundle concentrating portion (condensing zone). In order to concentrate the fiber bundle in such a small area, it is preferable to use a guide member having a pair of guide portions, each of which includes a tapered portion and a straight portion which continues on the downstream side of the tapered portion in the advancing direction of the fiber bundle. The tapered portions are formed so that the distance between the two guide surfaces gradually increases in the direction opposite to the advancing direction. The straight portions are formed so that the distance between the two guide surfaces is constant along the advancing direction. The fiber bundle is guided from the tapered portions to the straight portions. However, when the guide member is simply vibrated as in the above described publication, there is a possibility that a transition portion through which the fiber bundle moves from the tapered portions to the straight portions may become clogged with fiber bundle in the case where the amplitude of the vibration of the guide member is too small. In addition, the quality of the thread is negatively affected in the case where the amplitude in an outlet formed by the straight portions is too small.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a fiber bundle guiding apparatus for a spinning machine in which a transition portion through which a fiber bundle moves from tapered portions to straight portions in a guide member is prevented from becoming clogged with fibers, and at the same time, high quality thread can be spun stably.
To achieve the foregoing objective and in accordance with a first aspect of the present invention, a fiber bundle concentrating apparatus for a spinning machine is provided. The apparatus includes a guide member and an excitation device. The guide member guides a fiber bundle which moves along a predetermined advancing direction. The guide member has a pair of guide surfaces which face each other and guide a fiber bundle in such a manner that the width of the fiber bundle becomes narrower. The excitation device vibrates the guide member to generate sound pressure. The guide member is provided with a pair of guide portions in plate form which are placed in such a manner as to face each other so that the pair of guide surfaces are formed. The pair of guide portions each have a straight portion and a tapered portion which is located on the upstream side of the straight portion in the advancing direction of the fiber bundle. Each straight portion and the corresponding tapered portion are made continuous by a connection portion. The straight portions form an outlet through which the fiber bundle is fed out from the guide member. The straight portions are formed in such a manner that the distance between the two guide surfaces is constant along the advancing direction of the fiber bundle, and the tapered portions are formed in such a manner that the distance between the two guide surfaces gradually becomes greater toward a direction which is opposite to the advancing direction of the fiber bundle. The shape of the guide portions is set so that when the guide member is vibrated at a predetermined frequency by the excitation device. The outlet and the connection portions are located in locations different from the nodes of vibration.
In accordance with a second aspect of the present invention, a ring spinning machine having the fiber bundle concentrating apparatus according to the above first aspect of the present invention is provided.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:

Fig. 1A is a side view showing a draft device according to one embodiment of the present invention;
Fig. 1B is an enlarged side view showing a portion of the guide member shown in Fig. 1A;
Fig. 2A is a side view showing the guide member;
Fig. 2B is a front view showing the guide member;
Fig. 3 is a plan view schematically showing the relationship between the guide member and the bottom roller;
Fig. 4 is a graph showing the relationship between the quality of thread and the amplitude;
Figs. 5A and 5B are front views each showing a guide member according to a modified embodiment; and
Fig. 6 is a side view showing a portion of a guide member according to another modified embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, a fine spinning machine according to one embodiment of the present invention is described in reference to Figs. 1A to 4.
A draft device 11 shown in Fig. 1A is of a four-line type and provided with a three-line type draft part and a pair of final delivery rollers 26 provided on the downstream side of the above described draft part in an advancing direction of a fiber bundle F. The three-line type draft part is provided with a front bottom roller 12, a middle bottom roller 13 and a back bottom roller 14. Support brackets 16 and 17 are fixed in such a manner as to be adjustable in position in the front or rear direction relative to the roller stand 15 that forms the base of the machine, and the middle bottom roller 13 and the back bottom roller 14 are supported by these support brackets 16 and 17, respectively.
A front top roller 21, a middle top roller 22 and a back top roller 23 are respectively supported by the frame 20b of the weighting arm 20 so as to correspond to the front bottom roller 12, the middle bottom roller 13 and the back bottom roller 14, respectively, with top roller supporting members. The weighting arm 20 has a lever 20a which is rotatable between a pressure applying position and a released position. As shown in Fig. 1A, in a state where the lever 20a contacts the frame 20b in such a state as to be placed in a pressure applying position, the respective top rollers 21, 22 and 23 which are supported by the weighting arm 20 are held in a locked state in a pressure applying position (spinning position), in which the top rollers 21, 22 and 23 are pressed by the bottom rollers 12, 13 and 14. In addition, the above described locked state is cancelled in a state where the lever 20a has been rotated upward to the released position from the state shown in Fig. 1A.
The final delivery roller pair 26 includes a bottom nip roller 26a supported by the roller stand 15 and a top nip roller 26b supported by the weighting arm 20 with a support member. The top nip roller 26b is supported by the weighting arm 20 with a support member per two spindles, in the same manner as the front top roller 21 of the draft device 11.
A fiber bundle concentrating apparatus 30 that forms a fiber bundle guiding apparatus is placed between the final delivery roller pair 26 and the pair of front rollers 12 and 21 located on the upstream side of the final delivery roller pair 26. As shown in Fig. 2B, the fiber bundle concentrating apparatus 30 is provided with a guide member 31 and an excitation device 32 for vibrating the guide member 31. The excitation device 32 vibrates the guide member 31 in such a manner that sound pressure for reducing the width of the fiber bundle F is generated. That is, the sound pressure is applied to the fiber bundle F in such a direction that the width of the fiber bundle F is reduced.
The guide member 31 includes a pair of flat plates 33 and a spacer 34 for connecting the two flat plates 33 at a predetermined distance. Each flat plate 33 is provided with a proximal end portion 33a which is fixed to the spacer 34 through, for example, brazing, a middle portion 33b which is narrower than the proximal end portion 33a, and a guide portion 35, which extends approximately perpendicular to the middle portion 33b. That is to say, the guide member 31 is provided with a pair of guide portions 35 in plate form which face each other. The facing surfaces of the pair of guide portions 35 form the above described pair of guide surfaces 35a. The guide surfaces 35a guide the fiber bundle F in such a manner that the width of the fiber bundle F becomes smaller toward the advancing direction of the fiber bundle F. The middle portion 33b and the proximal end portion 33a of each flat plate 33 function as a support portion for supporting the guide portion 35. Each support portion is a portion in plate form which continues to the guide portion 35 and is connected to the excitation device 32.
As shown in Fig. 3, each guide portion 35 is provided with a straight portion 35b and a tapered portion 35c which is located on the upstream side of the straight portion 35b in the advancing direction of the fiber bundle F. The straight portions 35b are formed in such a manner that the distance between the two facing guide surfaces 35a is constant along the advancing direction of the fiber bundle F. The tapered portions 35c are formed in such a manner that the distance between the two facing guide surfaces 35a gradually and continuously becomes greater toward the direction opposite to the advancing direction of the fiber bundle F. The guide members 31 are formed so that the distance between the facing straight portions 35b is 1 mm or less, though this may be different depending on the conditions for spinning. As shown in Fig. 1B, the straight portions 35b and the tapered portions 35c continue via a connection portion 35e. The straight portions 35b form an outlet 35d through which the fiber bundle F is fed out from the guide member 31. The shape of the guide portions 35 is set in such a manner that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the location of the outlet 35d of the straight portion 35b and the location of the connection portion 35e become locations different from the nodes of vibration. The nodes of vibration correspond to portions where the amplitude of vibration for generating sound pressure in the guide surfaces 35a of the guide portions 35 is minimum in the longitudinal direction of the guide portions 35.
In this embodiment, the shape of the guide portions 35 is set in such a manner that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the location of the outlet 35d of the straight portions 35b and the location of the connection portions 35e coincide with peaks of vibration as shown in Fig. 1B. The peaks of vibration correspond to locations where the amplitude of the vibration for generating sound pressure on the guide surfaces 35a of the guide portions 35 is maximum in the longitudinal direction of the guide portions 35. In Fig. 1B, the left side of the straight line L indicated by a two-dot chain line is the straight portion 35b. In addition, the shape of the guide portions 35 is set in such a manner that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the total length of the guide portions 35 corresponds to the wavelength of the vibration. Accordingly, the length of the straight portions 35b is the same as the length of the tapered portions 35c.
The excitation device 32 is preferably provided with a transducer 36, which is a Langevin transducer, and this transducer 36 has a pair of piezoelectric elements 37a and 37b in ring form. An electrode plate 38 in ring form is placed between the two piezoelectric elements 37a and 37b, and metal blocks 39 and 40 contacting the surface of the respective piezoelectric elements 37a and 37b on the side opposite to the electrode plate 38. These piezoelectric elements 37a and 37b, the electrode plate 38, and the metal blocks 39 and 40 are secured and fastened to each other with bolts (not shown), and thus, the transducer 36 is formed. The bolt is screwed into a screw hole (not shown) created in the metal block 39 from the side of the metal block 40. The two metal blocks 39 and 40 are in such a state as to be electrically connected via the bolt. A flange 39a is formed at a distal end of the metal block 39, and the metal block 39 is secured to an attachment piece 41 through the flange 39a. The transducer 36 is secured to the roller stand 15 via the attachment piece 41 with a bolt (not shown).
The guide member 31 is secured to a horn 42 which is vibrated by the transducer 36. A distal end of the horn 42 is secured in a portion close to one end of the above described guide member 31 through brazing. The horn 42 is secured to the transducer 36 on the proximal end surface on the side opposite to the distal end surface to which the guide member 31 is secured. The distal end surface of the horn 42 is a plane perpendicular to the direction of the axis of the transducer 36.
The transducer 36 is connected to an oscillator 43. The electrode plate 38 is connected to the oscillator 43 via a wire 44a and the ground terminal of the oscillator 43 is connected to the metal block 40 via a wire 44b. The transducer 36, the horn 42 and the oscillator 43 form the excitation device 32 for vibrating the guide member 31. The oscillator 43 excites the transducer 36 so that the guide member 31 vibrates at a frequency higher than the audible region for humans.
Prior to the operation of the fine spinning machine, the location of the middle bottom roller 13 and the back bottom roller 14 is adjusted to an appropriate location by adjusting the location of the support brackets 16 and 17 in accordance with the material to be spun. The location of the middle top roller 22 and the back top roller 23 is also adjusted so as to correspond to the location of the middle bottom roller 13 and the back bottom roller 14.
When the fine spinning machine is operated, the fiber bundle F is drafted in the three-line type draft part of the draft device 11, and after that guided into the nipping portion of the final delivery roller pair 26 via the guide surfaces 35a of the guide members 31, and fed out through the final delivery roller pair 26. At the time of operation of the fine spinning machine, the transducer 36 is excited with the resonant frequency (for example approximately 30 kHz) of the guide member 31 as the oscillator 43 is driven, and as a result, the horn 42 vibrates longitudinally so as to generate flexural vibration of the guide members. The guide portion 35 extends in the direction in which the fiber bundle F is drawn out, and therefore, the guide portions 35 vibrate in wave form in a planar view. The vibration of these guide portions 35 has an amplitude in the direction of the longitudinal vibration of the horn 42 (in the left-right direction in Fig. 2B), and has peaks, which are locations where the amplitude is maximum, and nodes, which are locations where the amplitude becomes minimum. The fiber bundle F moves downstream while being twisted after passing through the nipping point between the bottom nip roller 26a and the top nip roller 26b, and is wound around a bobbin, not shown. The final delivery roller pair 26 are rotated in such a manner that the surface speed is slightly greater than the surface speed of the front bottom roller 12 and the front top roller 21, and therefore, the fiber bundle F changes in direction and moves downstream while being twisted after passing through the nipping point between the final delivery roller pair 26 in such a state as to be appropriately tense.
The fiber bundle F that is drafted in the three-line type draft part is guided into the space between the final delivery roller pair 26 in such a state as to be compressed so that the width is 1 mm or less while passing between the guide surfaces 35a. Accordingly, fuzzing and waste cotton are suppressed, so that the quality of the thread is improved in comparison with fine spinning machines where a three-line type draft device which does not have a fiber bundle concentrating apparatus 30 is provided.
It has been found out that simply guiding and concentrating the fiber bundle F in a vibration state is insufficient to prevent fiber clogging of the connection portions 35e between the straight portions 35b and the tapered portions 35c and gain high quality thread having little unevenness and little fluff. In addition, as shown in Fig. 4, the inventors of the present application found out that the quality of thread deteriorates when the amplitude in the guide portions 35, particularly the amplitude in the outlet 35d of the straight portions 35b and the connection portions 35e, is too small.
In this embodiment, the shape of the guide portions 35 is designed so that when the guide member 31 is vibrated by the excitation device 32, the outlet 35d of the straight portions 35b and the connection portion 35e are located in peaks of vibration. Therefore, the amplitude of the vibration becomes maximum in the connection portions 35e, which easily become clogged with fibers, and therefore, sound pressure applied to the fiber bundle F in the connection portions 35e also becomes greater. Thus, the energy for driving the excitation device 32 required to vibrate the guide member 31 is reduced to the utmost while preventing the guide portions 35 from becoming clogged with fibers. In addition, the amplitude of the vibration becomes maximum in the outlet 35d of the straight portions 35b. That is to say, the amplitude of the vibration becomes the tolerable value X or greater in Fig. 4 in the outlet 35d of the straight portions 35b and the connection portions 35e, so that the quality of the thread is prevented from deteriorating and the thread is prevented from being cut.
According to this embodiment, the following advantages are gained.

(1) The fiber bundle concentrating apparatus 30 is provided with an excitation device 32 for vibrating the guide member 31 so that sound pressure for reducing the width of the fiber bundle F is generated. Accordingly, the fiber bundle F is guided in such a state that there is little friction while preventing the state of friction on the guide surfaces 35a from deteriorating over time due to wear of the guide surfaces 35a caused by friction with the fiber bundle F and adhesion of foreign substances.
(2) The guide member 31 is provided with a pair of guide portions 35 in plate form having a guide surface 35a, and the pair of guide portions 35 are provided with a straight portion 35b and a tapered portion 35c located on the upstream side of the straight portion 35b in the advancing direction of the fiber bundle F. The distance between the guide surfaces 35a which face each other is constant in the straight portions 35b, and becomes greater in the tapered portion 35c toward the upstream side in the advancing direction of the fiber bundle F. The shape of the guide portions 35 is set so that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the location of the outlet 35d of the straight portions 35b and the location of the connection portions 35e are different from the nodes of vibration. Accordingly, a state where sufficient sound pressure cannot be gained in the outlet 35d of the straight portions 35b and the connection portions 35e is avoided, and thus, a transition portion through which the fiber bundle F moves from the tapered portions 35c to the straight portions 35b is prevented from becoming clogged with fibers. Also, thread with stable quality is spun.
(3) The shape of the guide portions 35 is set so that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the location of the outlet 35d of the straight portions 35b and the location of the connection portions 35e coincide with peaks of vibration. Accordingly, the amplitude of vibration becomes maximum in locations of the connection portions 35e which easily become clogged with fibers, and therefore, the transition portion through which the fiber bundle F moves from the tapered portions 35c to the straight portions 35b is prevented from becoming clogged with fibers while the excitation device 32 is excited by as small a drive energy as possible.
(4) In addition, the shape of the guide portions 35 is set so that when the guide member 31 is vibrated at a predetermined frequency by the excitation device 32, the total length of the guide portions 35 corresponds to the wavelength of vibration. Thus, the amplitude of the vibration in the outlet 35d of the straight portions 35b and the connection portions 35e becomes large in comparison with the case where the entire length of the guide portions 35 corresponds to twice the wavelength or more of the vibration under such conditions that the energy for driving the excitation device 32 is the same. Therefore, the transition portion through which the fiber bundle F moves from the tapered portions 35c to the straight portions 35b is prevented from becoming clogged with fibers more effectively, and at the same time, thread with more stable quality is spun.
(5) The guide member 31 is formed of two flat plates 33 which are connected with a spacer 34 in between. Accordingly, the guide portions 35 are formed so as to have a predetermined distance in between and in a desired form with high precision as compared to the case where the guide member is formed by bending one sheet of plate material.

The invention is not limited to the above described embodiment, and the above described embodiment may be modified as follows, for example.
The guide portions 35 may be formed so as to have a length which does not correspond to the wavelength of vibration, while the location of the outlet 35d of the straight portions 35b and the location of the connection portions 35e coincide with peaks of vibration. The number of nodes of vibration is not limited to one between the outlet 35d and the connection portions 35e which are located in peaks of vibration, for example. The number of nodes may be N, which is a natural number no less than two, and thus, the guide portions 35 may be formed so as to have a length which corresponds to N times the wavelength of vibration. Under conditions where the length of the guide portions is the same, however, the amplitude in peak portions becomes larger as the frequency of vibration becomes lower, and therefore, it is preferable for the guide portions 35 to have a total length which corresponds to the wavelength of vibration.
It is not necessary for the location of the outlet 35d and the location of the connection portions 35e to coincide with peaks of vibration, and they may be different from the nodes of vibration. If the location of the outlet 35d and the location of the connection portions 35e coincide with the nodes of vibration, the amplitude of vibration cannot be sufficiently large in the outlet 35d and the connection portions 35e. Contrastingly, if the location of the outlet 35d and the location of the connection portions 35e are different from the nodes of vibration, the amplitude can be sufficiently large, depending on the energy applied to the excitation device 32. However, if the outlet 35d and the connection portions 35e are located close to the nodes of vibration the energy required for making the amplitude of vibration sufficiently large in the outlet 35d and the connection portions 35e becomes large. Therefore, it is preferable for the outlet 35d and the connection portions 35e to be located close to peaks of vibration. "Close to the peak of vibration" means that the distance from a peak of vibration is, for example, in a range within 20% of the distance between an adjacent peak and node.
The guide members 31 are not limited to having a configuration where two flat plates 33 are connected via a spacer 34. The guide member 31 shown in Fig. 5A is provided with a single proximal end portion 33a secured to a horn 42, a pair of middle portions 33b in plate form which are provided integrally with this proximal end portion 33a, and a pair of guide portions 35 in plate form which are provided integrally with the distal ends of the pair of middle portions 33b. The guide member 31 shown in Fig. 5B is provided with a proximal end portion 33a in single plate form, a middle portion 33b in single plate form, and a pair of guide portions 35 in plate form. The guide member 31 in Fig. 2B and the guide member 31 in Fig. 5A make it easier to form the guide portions 35 in such a manner that the guide portions 35 vibrate as desired than the guide members 31 in Fig. 5B.
The straight portions 35b may be longer than the tapered portions 35c instead of the configuration where the connection portions 35e are located at approximately the center in the longitudinal direction of the guide portions 35. The length between the connection portions 35e and the outlet 35d in the guide portions 35 shown in Fig. 6 is approximately two times greater than the length between the connection portions 35e and the inlet of the guide portions 35. In addition, the total length of the guide portions 35 corresponds to 3/2 the wavelength of vibration, so that the four locations of the outlet 35d, the center portion between the outlet 35d and the connection portions 35e, the connection portions 35e and the inlet of the tapered portions 35c coincide with peaks of vibration. In this case, it is preferable for the middle portion 33b to be connected to a guide portion 35 in one of three portions corresponding to the nodes of vibration.
The straight portions 35b may be shorter than the tapered portions 35c.
The tapered portions 35c do not necessarily extend in straight line form in such a manner that the guide surfaces 35a become a plane, but may curve in such a manner that the guide surfaces 35a become a curved surface. Thus, the tapered portions 35c and the straight portions 35b smoothly continue through the connection portions 35e, which is preferable. In addition, in the case where the tapered portions 35c extend essentially in straight line form, only portions in the vicinity of the connection portions 35e may be smoothly curved, so that the tapered portions 35c smoothly continue to the straight portions 35b.
As in the configuration described in Japanese Laid-Open Patent Publication No. 2007-9391 , the guide member 31 may be formed of two independent plates, and transducers 36 may be attached to the respective plates.
The shape of the sides of the guide portions 35 is not limited to a shape which becomes narrower toward the two ends (inlet and outlet) in the longitudinal direction, but may be in such a shape as to have a constant width throughout the entirety in the longitudinal direction.
The guide member 31 may be secured to the horn 42 through soldering or using an adhesive, or secured and fastened with a bolt, instead of being secured through brazing.
The horn 42 may have any form, for example truncated cone form or columnar form.
The transducer 36 of the excitation device 32 is not limited to a piezoelectric element, and may be formed of a magnetostrictor or a super magnetostrictor.
A fiber bundle concentrating apparatus includes a guide member having a pair of guide surfaces which face each other and guide a fiber bundle so that the width of the fiber bundle is narrowed, and an excitation device for vibrating the guide member to generate sound pressure. The guide member includes a pair of guide portions which are placed to face each other, so that the guide surfaces are formed. Each guide portion has a straight portion and a tapered portion, which are made continuous by a connection portion. The straight portions are formed so that the distance between the two guide surfaces is constant, and the tapered portions are formed so that the distance between the two guide surfaces gradually becomes greater toward a direction opposite to the advancing direction of the fiber bundle. The straight portions form an outlet through which the fiber bundle is fed out from the guide member. The shape of the guide portions is set so that when the guide member is vibrated at a predetermined frequency by the excitation device, the outlet and the connection portions are located in locations different from the nodes of vibration.

Claims

A fiber bundle concentrating apparatus for a spinning machine, comprising:
a guide member (31) for guiding a fiber bundle (F) which moves along a predetermined advancing direction, the guide member (31) having a pair of guide surfaces (35a) which face each other and guide a fiber bundle (F) in such a manner that the width of the fiber bundle (F) becomes narrower; and

an excitation device (32) for vibrating the guide member (31) to generate sound pressure,
wherein the guide member (31) is provided with a pair of guide portions (35) in plate form which are placed in such a manner as to face each other so that the pair of guide surfaces (35a) are formed, the pair of guide portions (35) each have a straight portion (35b) and a tapered portion (35c) which is located on the upstream side of the straight portion (35b) in the advancing direction of the fiber bundle (F), each straight portion (35b) and the corresponding tapered portion (35c) are made continuous by a connection portion (35e), the straight portions (35b) form an outlet (35d) through which the fiber bundle (F) is fed out from the guide member (31), the straight portions (35b) are formed in such a manner that the distance between the two guide surfaces (35a) is constant along the advancing direction of the fiber bundle (F), and the tapered portions (35c) are formed in such a manner that the distance between the two guide surfaces (35a) gradually becomes greater toward a direction which is opposite to the advancing direction of the fiber bundle (F), the fiber bundle concentrating apparatus being characterized in that:
the shape of the guide portions (35) is set so that when the guide member (31) is vibrated at a predetermined frequency by the excitation device (32), the outlet (35d) and the connection portions (35e) are located in locations different from the nodes of vibration.
The fiber bundle concentrating apparatus according to claim 1, characterized in that the shape of the guide portions (35) is set so that when the guide member (31) is vibrated at the predetermined frequency by the excitation device (32), the outlet (35d) and the connection portions (35e) are respectively located in a peak of vibration.
The fiber bundle concentrating apparatus according to claim 1 or 2, characterized in that the shape of the guide portions (35) is set so that when the guide member (31) is vibrated at the predetermined frequency by the excitation device (32), the total length of the guide portions (35) corresponds to the wavelength of vibration.
The fiber bundle concentrating apparatus according to any one of claims 1 to 3, characterized in that the tapered portions (35c) form an inlet through which a fiber bundle (F) is introduced into the guide member (31), and the length between the connection portion (35e) and the inlet is equal to the length between the connection portion (35e) and the outlet (35d) .
The fiber bundle concentrating apparatus according to any one of claims 1 to 4, characterized in that the guide member (31) is provided with a pair of support portions (33a, 33b) in plate form, each support portion (33a, 33b) being continuous to one of the pair of guide portions (35) and is connected to the excitation device (32).
The fiber bundle concentrating apparatus according to any one of claims 1 to 5, characterized in that the guide member (31) is provided with a pair of plates (33), which include the pair of guide portions (35), and a spacer (34) for connecting the pair of plates (33) at a predetermined distance.
A ring spinning machine comprising the fiber bundle concentrating apparatus according to any one of claims 1 to 6.