Description:TECHNICAL FIELD
[0001] The present invention relates to adjustment of a position of a draft roller for drafting a fiber bundle.

BACKGROUND ART
[0002] In the following description, the Japanese Patent Application Publication No. 2013-522485 may be referred to as PTL 1.
[0003] A drafting apparatus that drafts a fiber bundle by driving an apron belt is known to the public. This type of the drafting apparatus is disclosed, for example, in PTL 1.
[0004] In the drafting apparatus of PTL 1, a guide apron is looped around a bottom roller and a guide table. The bottom roller is supported by a bearing carriage. The bearing carriage is movable in a conveying direction of fibers.

SUMMARY OF THE INVENTION
[0005] The tension applied to the apron belt significantly effects quality of yarn, operation capacity, power consumption, and life of the apron belt itself. Because of the recent increase in the spinning speed, it is important to maintain the tension of the apron belt appropriately.
[0006] In the configuration of PTL 1, the tension of the guide apron can be adjusted by changing the distance between the guide table and the bottom roller. However, in the configuration of PTL 1, since the bottom roller is slid to change the distance, twisting is prone to occur and thus the bottom roller may not be smoothly displaced.
[0007] The present invention is made in view of the situation described above and its purpose is to achieve smooth displacement of a draft roller.
[0008] A first aspect of the present invention provides a draft roller assembly with a configuration described below. That is, the draft roller assembly includes a base member, a housing, a bearing, a draft roller, and a belt guide member. A through hole is formed through the housing. The bearing is inserted into the through hole. The draft roller is rotatably supported by the bearing. The belt guide member guides an apron belt. The housing is rotatable with respect to the base member. Rotation of the housing with respect to the base member changes a distance between the housing and the belt guide member.
[0009] Accordingly, the distance between the draft roller and the belt guide member can be smoothly changed by rotating the housing.
[0010] The above-described draft roller assembly preferably includes the apron belt that is looped around the draft roller and the belt guide member.
[0011] Accordingly, the tension of the apron belt can be smoothly adjusted by rotating the housing.
[0012] The above-described draft roller assembly preferably includes a biasing member that biases the housing to one side in the rotational direction.
[0013] Accordingly, the housing can be rotated by force of a predetermined magnitude by using the biasing member in a direction to stretch the apron belt.
[0014] In the above-described draft roller assembly, it is preferable to include a configuration as follows. That is, the housing is rotatable about a rotary shaft with respect to the base member. The biasing member is a spring attached to the rotary shaft.
[0015] Accordingly, the housing can be biased to one side in the rotational direction with a simple configuration.
[0016] In the above-described draft roller assembly, it is preferable that a magnitude of a spring force is adjustable by changing a position to which the spring is fixed.
[0017] Accordingly, the tension applied to the apron belt can be changed according to a situation.
[0018] In the above-described draft roller assembly, it is preferable to include a configuration as follows. That is, the draft roller assembly includes a first member and a second member. The first member protrudes from the base member. The second member is fixed to the first member. The belt guide member is fixed to the second member.
[0019] Accordingly, the belt guide member can be fixed at an accurate position.
[0020] The above-described draft roller assembly preferably includes an angle fixer that fixes a rotational angle of the housing.
[0021] Accordingly, positional relation between the belt guide member and the draft roller can be reliably maintained.
[0022] In the above-described draft roller assembly, it is preferable that the angle fixer includes a fixing member that is fixed in a direction parallel to the rotational axis of the housing.
[0023] Accordingly, the housing can be prevented from rotating unintentionally when fixing the angle of the housing using the fixing member.
[0024] In the above-described draft roller assembly, it is preferable to include a configuration as follows. That is, the draft roller assembly includes a fiber bundle bundling member that bundles a fiber bundle. The fiber bundle bundling member is fixed to the housing.
[0025] Accordingly, positional accuracy of the fiber bundle bundling member with respect to the draft roller can be improved. Thus, quality of drafting of the fiber bundle is improved.
[0026] The above-described draft roller assembly preferably includes a stopper that restricts the housing from rotating in a direction away from the belt guide member at an angle greater than a predetermined angle.
[0027] Accordingly, ease of assembling can be improved.
[0028] In the above-described draft roller assembly, it is preferable to include a configuration as follows. That is, two fiber bundle paths are formed in the draft roller assembly, the respective fiber bundle paths being a path along which the fiber bundle can travel. A pair of the housings, a pair of the draft rollers, and a pair of the belt guide members are provided for the two fiber bundle paths. An angle fixer that fixes a rotational angle of the housing is arranged for each of the housings. The angle fixer is located farther from a middle position between the two fiber bundle paths than the housing.
[0029] Accordingly, the angle fixer can be easily accessed from outside. Thus, ease of adjusting the position of the draft roller is improved.
[0030] A second aspect of the present invention provides a drafting apparatus with a configuration as follows. The drafting apparatus includes a base member, a first housing, a bearing, a first draft roller, and a belt guide member. A through hole is formed through the first housing. The bearing is inserted into the through hole. The first draft roller is rotatably supported by the bearing. The belt guide member guides an apron belt. The first housing is rotatable with respect to the base member. Rotation of the first housing with respect to the base member changes a distance between the first housing and the belt guide member.
[0031] Accordingly, the distance between the draft roller and the belt guide member can be smoothly changed by rotating the housing.
[0032] The above-described drafting apparatus may include a configuration as follows. That is, the drafting apparatus includes a first member and a second member. The first member protrudes from the base member. The second member is fixed to the first member. The belt guide member is fixed to the second member.
[0033] Accordingly, the positional accuracy of the belt guide member is improved.
[0034] The above-described drafting apparatus may include a configuration as follows. That is, the drafting apparatus includes a second draft roller, a second housing, and an installed member. The second draft roller is arranged downstream of the first draft roller in a fiber traveling direction. The second housing rotatably supports the second draft roller. The installed member is fixedly provided on the second housing. The belt guide member is fixed to the installed member.
[0035] Accordingly, positional accuracy of the belt guide member with respect to the second draft roller can be improved.
[0036] In the above-described drafting apparatus, it is preferable to include a configuration as follows. That is, the drafting apparatus includes a supporting member, a second housing, and a second draft roller. The supporting member rotatably supports the first housing. The second housing is integrally formed with the base member. The second draft roller is arranged downstream of the first draft roller in a fiber traveling direction and is supported by the second housing. The supporting member is detachably fixed with respect to the base member.
[0037] Accordingly, maintenance around the first housing can be easily performed.
[0038] In the above-described drafting apparatus, it is preferable to include a configuration as follows. That is, the drafting apparatus includes a traversing apparatus that traverses an apron belt. The apron belt is looped around the first draft roller and the belt guide member. A traversing member of the traversing apparatus is positioned with respect to the supporting member.
[0039] Accordingly, since positional accuracy of the traversing member with respect to the apron belt is improved, smooth traversing motion of the traversing member can be achieved.
[0040] In the above-described drafting apparatus, it is preferable to include a configuration as follows. That is, two fiber bundle paths are formed in the drafting apparatus, the respective fiber bundle paths being a path along which the fiber bundle can travel. A pair of the first housings, a pair of the first draft rollers, and a pair of the belt guide members are provided for the two fiber bundle paths. An angle fixer that fixes a rotational angle of the first housing is provided for each of the first housings. The angle fixer is located farther from a space between the two fiber bundle paths than the first housing.
[0041] Accordingly, the angle fixer can be easily accessed from outside. Thus, ease of adjusting the position of the draft roller is improved.
[0042] A third aspect of the present invention provides a spinning machine with a configuration as follows. That is, the spinning machine includes a drafting apparatus, a spinning apparatus, and a winding apparatus. The drafting apparatus includes the above-described draft roller assembly or includes the above-described configuration. The spinning apparatus forms a yarn by applying swirling airflow on a fiber bundle drafted by the drafting apparatus. The winding apparatus winds the yarn formed by the spinning apparatus into a package.
[0043] Accordingly, the spinning machine that can displace the draft roller smoothly for maintenance or the like can be achieved. As a result, the quality of the yarn formed by the spinning machine is improved.

BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a front view of a spinning machine according to one embodiment of the present invention.
FIG. 2 is a side view of a spinning unit.
FIG. 3 is a side view schematically showing a drafting apparatus.
FIG. 4 is a perspective view showing a lower part of a drafting apparatus.
FIG. 5 is a perspective view showing a draft roller assembly in detail.
FIG. 6 is an exploded perspective view of a draft roller assembly.
FIG. 7 is a perspective view showing a side of a lower part of a drafting apparatus.
FIG. 8 is a perspective view showing a state in which a rotary housing rotated from the state shown in FIG. 7.
FIG. 9 is a perspective view showing a lower part of a drafting apparatus.
FIG. 10 is a perspective view showing a variation of a second support.

EMBODIMENT FOR CARRYING OUT THE INVENTION
[0045] Next, a spinning machine 1 that includes a drafting apparatus 5 according to one embodiment of the present invention will be described below with reference to the drawings. The spinning machine 1 shown in FIG. 1 includes more than one spinning unit 2 arranged side by side, a frame 3, and a yarn joining cart 30.
[0046] As shown in FIG. 2, each of the spinning units 2 includes a fiber bundle guide 4, the drafting apparatus 5, an air spinning apparatus (a spinning apparatus) 6, a yarn monitoring apparatus 7, a yarn storage apparatus 8, and a winding apparatus 9, in the order from upstream to downstream. Each apparatus that the spinning unit 2 includes is supported by the frame 3. In the present specification, the terms “upstream” and “downstream” shall mean the upstream and the downstream in a traveling direction of the fiber bundle and the yarn during spinning.
[0047] The fiber bundle guide 4 guides a fiber bundle 10 supplied from a sliver case that is not shown in the drawings. The fiber bundle 10 guided by the fiber bundle guide 4 is fed to the drafting apparatus 5.
[0048] The drafting apparatus 5 drafts the fiber bundle 10. The drafting apparatus 5 includes a draft bottom roller group 5a and a draft top roller group 5b as components for drafting. The draft bottom roller group 5a includes more than one draft bottom roller. The draft bottom rollers are rotationally driven by motors not shown in the drawings. The draft top roller group 5b includes more than one draft top roller. The draft bottom rollers and the draft top rollers are arranged to face each other. By conveying the fiber bundle 10 while sandwiching it between the draft bottom rollers and the draft top rollers, the fiber bundle 10 can be stretched. The drafting apparatus 5 will be described in detail later.
[0049] The air spinning apparatus 6 can perform air spinning by generating a swirling airflow inside. The air spinning apparatus 6 performs spinning by applying twists to the fiber bundle 10 supplied from the drafting apparatus 5 with a swirling airflow to form a yarn 15. Instead of the air spinning apparatus 6, an apparatus that performs a ring spinning may be used.
[0050] The yarn 15 formed by the air spinning apparatus 6 travels through the yarn monitoring apparatus 7. The yarn monitoring apparatus 7 monitors the thickness of the travelling yarn 15 using an optical sensor not shown in the drawings. When the yarn monitoring apparatus 7 detects a yarn defect in the yarn 15 (for example, a point where the thickness of the yarn 15 is abnormal), it sends a yarn defect detection signal to a unit controller 26. When the unit controller 26 receives the yarn defect detection signal, it cuts the yarn 15. The unit controller 26 may stop the air spinning apparatus 6 to cut the yarn 15, or may drive a cutter to cut the yarn 15. Instead of the optical sensor, the yarn monitoring apparatus 7 may monitor the thickness of the yarn 15 using, for example, a capacitive sensor. As yarn defects, a foreign substance included in the yarn 15 and/or an abnormal tension of the yarn 15 may be monitored.
[0051] After traveling through the yarn monitoring apparatus 7, the yarn 15 is wound on a bobbin 17 by the winding apparatus 9. The winding apparatus 9 winds the yarn 15 to produce a package 18. The winding apparatus 9 includes a cradle arm 19, a winding drum 20, and a traversing apparatus 21.
[0052] The cradle arm 19 rotatably supports the bobbin 17 for winding the yarn 15. Being rotationally driven while making contact with the outer peripheral surface of the bobbin 17 or the outer peripheral surface of the package 18, the winding drum 20 rotates the bobbin 17 (or the package 18). The traversing apparatus 21 includes a traverse guide 22. The traverse guide 22 is driven in a winding width direction of the bobbin 17 while being engaged with the yarn 15. Accordingly, the yarn 15 being wound onto the bobbin 17 can be traversed.
[0053] With the spinning unit 2 with the configuration as described above, the yarn 15 can be formed from the fiber bundle 10 and be wound onto the bobbin 17.
[0054] In the spinning machine 1 of the present embodiment, the yarn storage apparatus 8 is arranged between the yarn monitoring apparatus 7 and the winding apparatus 9. As shown in FIG. 2, the yarn storage apparatus 8 includes a yarn storage roller 23 and an electric motor 25 that rotationally drives the yarn storage roller 23.
[0055] With the electric motor 25 rotationally driving the yarn storage roller 23, the yarn storage apparatus 8 draws out the yarn 15 from the air spinning apparatus 6. The yarn storage roller 23 can wind and temporarily store the drawn out yarn 15 by winding the yarn 15 on its outer peripheral surface. Since the yarn 15 is temporarily stored in this manner, the yarn storage apparatus 8 functions as a kind of a buffer. This can eliminate problems (for example, slack of the yarn 15) that occur when the speed of the spinning by the air spinning apparatus 6 and the speed of the winding by the winding apparatus 9 do not match for some reason.
[0056] Each of the spinning units 2 includes the unit controller 26. The unit controller 26 controls each configuration that the spinning unit 2 includes. One unit controller 26 may be configured to control two or more predetermined number of the spinning units 2.
[0057] As shown in FIG. 1 and FIG. 2, the yarn joining cart 30 includes a yarn joining apparatus 31, a suction pipe 32, and a suction mouth 33.
[0058] The yarn joining apparatus 31 is an apparatus for joining ends of yarns together. The configuration of the yarn joining apparatus 31 is not particularly limited. For example, a pneumatic splicer that twists ends of yarns together by a swirling airflow may be employed. The yarn joining apparatus 31 may be a knotter that mechanically ties ends of yarns together. The suction pipe 32 sucks and captures an end of the yarn delivered from the air spinning apparatus 6 and guides it to the yarn joining apparatus 31. The suction mouth 33 sucks and captures an end of the yarn from the package 18 supported by the winding apparatus 9 and guides it to the yarn joining apparatus 31.
[0059] The yarn joining apparatus 31 joins ends of yarns guided by the suction pipe 32 and the suction mouth 33. Accordingly, the cut yarn 15 becomes continuous again between the air spinning apparatus 6 and the winding apparatus 9.
[0060] Next, with reference to FIG. 3, the drafting apparatus 5 will be described.
[0061] As shown in FIG. 3, the drafting apparatus 5 includes a draft base (base member) 50. The draft base 50 is a frame-like or block-like member. The draft base 50 is fixed to the frame 3 by suitable means.
[0062] The draft bottom roller group 5a and the air spinning apparatus 6 are attached to the draft base 50. The draft base 50 supports the draft bottom roller group 5a and the air spinning apparatus 6. As shown in FIG. 3, the draft bottom roller group 5a includes a front bottom roller (a second draft roller) 51, a middle bottom roller (a draft roller, a first draft roller) 52, a third bottom roller 53, and a back bottom roller 54 that are arranged in the order from downstream to upstream in the fiber traveling direction. A tensor bar (a belt guide member) 56 is arranged downstream of the middle bottom roller 52 in the fiber traveling direction. Since the fiber bundle 10 is drafted in the fiber traveling direction in the drafting apparatus 5, a direction of drafting is parallel to the fiber traveling direction. A bottom apron belt (an apron belt) 57 is looped around the middle bottom roller 52 and the tensor bar 56. A condenser (a fiber bundle bundling member) 58 is arranged between the middle bottom roller 52 and the third bottom roller 53. The condenser 58 restricts the width of the fiber bundle 10 supplied to the middle bottom roller 52 (in other words, the bottom apron belt 57) and bundles the fiber bundle 10.
[0063] The drafting apparatus 5 includes more than one motor not shown in the drawings. Each of the motors can rotationally drive the front bottom roller 51, the middle bottom roller 52, the third bottom roller 53, and the back bottom roller 54.
[0064] As shown in FIG. 3, the drafting apparatus 5 includes a draft cradle 90. The draft top roller group 5b is attached to the draft cradle 90 and the draft cradle 90 supports the draft top roller group 5b. The draft cradle 90 can be opened and closed with respect to the draft base 50. When the draft cradle 90 is closed, the draft top roller group 5b comes into contact with or comes close to the daft bottom roller group 5a. As shown in FIG. 3, the draft top roller group 5b includes a front top roller 91, a middle top roller 92, a third top roller 93, and a back top roller 94 in the order from downstream to upstream in the fiber traveling direction. A top apron belt 97 is looped around the middle top roller 92.
[0065] As shown in FIG. 4, in the present embodiment, two draft bottom roller groups 5a and two air spinning apparatuses 6 are arranged side by side with respect to one draft base 50. In other words, in the present embodiment, two fiber bundle paths are arranged side by side with respect to one draft base 50. The alignment direction of the two draft bottom roller groups 5a and the alignment direction of the two air spinning apparatuses 6 in the one draft base 50 are parallel to the axial directions of the draft rollers of the draft bottom roller group 5a. In the following description, a direction parallel to the axial directions of the draft rollers in the draft bottom roller group 5a may be referred to a roller axial direction. Since the two draft bottom roller groups 5a and their supporting structures are symmetrical with respect to a line of symmetry L1, a description will be made collectively. The line of symmetry L1 is arranged in the middle of the two fiber bundle paths.
[0066] Consider a projection plane obtained by projecting onto a plane parallel to the two fiber bundle paths, the draft base 50 and the two fiber bundle paths in a direction perpendicular to the plane. In this projection plane, the draft base 50 is arranged between the two fiber bundle paths. In detail, when viewed from a direction perpendicular to both the roller axial direction and the fiber traveling direction, the draft base 50 is arranged in the projection plane at a position that includes a middle position between the two draft bottom roller groups 5a. Accordingly, one draft base 50 can be arranged for two draft bottom roller groups 5a. The draft base 50 is formed to be substantially symmetrical with respect to the line of symmetry L1.
[0067] As shown in FIG. 4, the drafting apparatus 5 includes a first support (a second housing) 61, a second support 62, a third support 63, and a fourth support 64. Each of the first support 61, the second support 62, the third support 63, and the fourth support 64 is integrally formed with the draft base 50 or is attached to the draft base 50.
[0068] The first support 61 supports the front bottom roller 51 in a cantilever manner. The second support 62 supports the middle bottom roller 52 in a cantilever manner. The third support 63 supports both ends of the third bottom roller 53. The fourth support 64 supports both ends of the back bottom roller 54.
[0069] One first support 61 is arranged for each front bottom roller 51. The first support 61 supports an end of the front bottom roller 51 closer to the line of symmetry L1 than the other. One second support 62 is arranged for each middle bottom roller 52. The second support 62 supports an end of the middle bottom roller 52 closer to the line of symmetry L1 than the other.
[0070] The first support 61 is integrally formed with the draft base 50 to protrude upward from the draft base 50. The second support 62 is arranged to protrude upward from the draft base 50.
[0071] As shown in FIG. 5, the second support 62 includes a supporting member (a first member) 62a and a rotary housing (a housing, a first housing) 62b. In FIG. 5, the rotary housing 62b is transparently depicted by a chain line. In FIG. 5 and FIG. 6, the third support 63 and the fourth support 64 are omitted for brevity of the drawings.
[0072] The supporting member 62a is arranged to protrude upward from the draft base 50 and is fixed to the draft base 50. As shown in FIG. 6, the supporting member 62a is fixed to the draft base 50 with more than one (in the present embodiment, three) screw 87. By removing these screws 87, the supporting member 62a can be separated from the draft base 50.
[0073] As shown in FIG. 5, the lower portion of the supporting member 62a is formed cylindrical that is elongate in the roller axial direction. A round bar-shaped shaft member (rotary shaft) 66 is inserted into this cylindrical portion and fixed thereto. The shaft member 66 is oriented parallel to the roller axial direction and both its ends protrude from the supporting member 62a. The shaft member 66 is fixed to the supporting member 62a by suitable means such as a pin not shown in the drawings such that the shaft member 66 does not relatively rotate with respect to the supporting member 62a.
[0074] The rotary housing 62b includes a cylindrical portion 67 that rotatably supports the axis of the middle bottom roller 52. The cylindrical portion 67 is formed to be elongate in the roller axial direction. A pair of supporting arms 68 are integrally formed with the cylindrical portion 67 to protrude downward from both ends of the cylindrical portion 67. A connecting hole 69 is formed in a bottom end portion of each of the supporting arms 68 and the connecting holes are rotatably coupled to the ends of the shaft member 66. A bush-like bearing not shown in the drawings is arranged between the shaft member 66 and the connecting hole 69. Accordingly, the rotary housing 62b can be supported with respect to the supporting member 62a (in other words, the draft base 50) in a manner that the rotary housing 62b can rotate around the shaft member 66.
[0075] As shown in FIG. 5, a through hole 70 is formed through the cylindrical portion 67 along the roller axial direction. Two bearings 71 are inserted into this through hole 70. The shaft of the middle bottom roller 52 is attached to the through hole 70 via two bearings 71. In this manner, the middle bottom roller 52 is supported by the rotary housing 62b in such a way that it can be rotated by the bearings 71.
[0076] A fixing arm (a second member) 72 is fixed to a top portion of the supporting member 62a. As shown in FIG. 6, the fixing arm 72 is fixed to the supporting member 62a with more than one (in the present embodiment, two) screw 88. The fixing arm 72 extends in a direction away from the line of symmetry L1 to protrude from the supporting member 62a and the tensor bar 56 is fixed to its end portion. The tensor bar 56 is arranged between the front bottom roller 51 and the middle bottom roller 52.
[0077] In the supporting member 62a, a biasing spring (a biasing member) 73 is attached to a portion near the end portion of the shaft member 66 located farther from the line of symmetry L1 than the other. The biasing spring 73 is formed like a torsion coil spring and its coiled portion is arranged around the outer peripheral of the shaft member 66. To accommodate the coiled portion of the biasing spring 73, a spring accommodation space 74 is formed around the shaft member 66 in the supporting member 62a. The spring accommodation space 74 is a recess which opens at one side of the supporting member 62a in the axial direction and of which its top portion is open. The coiled portion of the biasing spring 73 is arranged between one supporting arm 68 that is located farther from the line of symmetry L1 than the other and the supporting member 62a.
[0078] One end of the spring wire of the biasing spring 73 formed like the torsion coil spring is inserted to a first recess 75 formed on the inner wall of the spring accommodation space 74. The other end of the spring wire extends upward from the spring accommodation space 74 and is inserted into a second recess 76 formed on the supporting arm 68. The biasing spring 73 applies a spring force to the rotary housing 62b in a direction in which the middle bottom roller 52 moves away from the tensor bar 56.
[0079] As shown in FIG. 5, more than one first recess 75 is formed at different phases (positions). By selecting the first recess 75 to insert the spring wire of the biasing spring 73, the fixed position of the biasing spring 73 can be changed. As a result, the spring force of the biasing spring 73 can be changed to obtain desired tension of the bottom apron belt 57. However, the number of the first recess 75 may be only one.
[0080] On one end surface of the shaft member 66 that is located farther from the line of symmetry L1 than the other, an adjusting plate 77 is fixed in a manner that the adjusting plate 77 does not relatively rotate. An arcuate and elongate adjusting hole 78 is formed on the adjusting plate 77. An angle fixing screw (a fixing member) 79 is inserted into this adjusting hole 78. The angle fixing screw 79 is fixed to a screw hole formed on the supporting arm 68. The axial direction of the angle fixing screw 79 is parallel to the roller axial direction.
[0081] By tightening the angle fixing screw 79, the rotary housing 62b is fixed so that it does not relatively rotate with respect to the shaft member 66 (in other words, the supporting member 62a). By loosening the angle fixing screw 79, the rotary housing 62b becomes relatively rotatable. Thus, the rotary housing 62b is moved in a direction away from the tensor bar 56 by the spring force of the biasing spring 73. In this manner, the adjusting plate 77 and the angle fixing screw 79 constitute an angle fixer 85 that fixes the rotational angle of the rotary housing 62b.
[0082] Drafting of the fiber bundle 10 by the drafting apparatus 5 is performed with the angle fixing screw 79 tightened. With the operation of the drafting apparatus 5, the bottom apron belt 57 may be stretched and lose tension. In this case, an operator loosens the angle fixing screw 79 in the state shown in FIG. 7 in which the drafting apparatus 5 is stopped. When the rotary housing 62b fixed by the angle fixing screw 79 is unfixed, the rotary housing 62b rotates by the action from the biasing spring 73 in the direction in which the middle bottom roller 52 moves away from the tensor bar 56. The rotary housing 62b rotates as shown in FIG. 8 until the tension of the bottom apron belt 57 and the spring force of the biasing spring 73 becomes equal and then stops. Under this state, the operator tightens the angle fixing screw 79. Accordingly, the drafting apparatus 5 can resume the operation with the tension of the bottom apron belt 57 recovered. The above-described tension adjusting operation may be performed periodically or may be performed irregularly triggered by a decrease of the quality of the yarn detected by the yarn monitoring apparatus 7 or the like.
[0083] In the present embodiment, the displacement of the middle bottom roller 52 with respect to the tensor bar 56 is realized by the rotation of the rotary hosing 62b, not by the parallel movement as disclosed in PTL 1. Therefore, twisting, a hold or the like are less likely to occur and the smooth displacement of the middle bottom roller 52 can be easily achieved.
[0084] The direction in which the adjusting hole 78 is tightened by the angle fixing screw 79 is parallel to the rotational axis of the rotary housing 62b. Therefore, the positional accuracy of the middle bottom roller 52 can be improved because a force in the rotational direction is less likely to be applied to the rotary housing 62b when tightening the angle fixing screw 79.
[0085] An arcuate and elongate guide hole 80 is formed on one supporting arm 68. In accordance with this guide hole 80, a restricting pin (a stopper) 81 is fixed to the supporting member 62a to protrude from it. The restricting pin 81 is inserted in the guide hole 80 under a state in which it extends in the roller axial direction.
[0086] When the angle fixing screw 79 is completely removed from the adjusting hole 78, the rotary housing 62b to which the spring force of the biasing spring 73 is applied attempts to rotate significantly with respect to the supporting member 62a. However, the restricting pin 81 hits the end portion of the guide hole 80 and the rotary housing 62b is prevented from rotating more than a predetermined angle with respect to the supporting member 62a. Since the range of the rotational angle of the rotary housing 62b is suitably limited, the second support 62 during assembling operation is kept compact, for example, and the ease of assembly is improved.
[0087] One third support 63 is arranged for two third bottom rollers 53 as shown in FIG. 4 and is arranged to connect the two third bottom rollers 53. One fourth support 64 is arranged for two back bottom rollers 54 and is arranged to connect the two back bottom rollers. The third support 63 and the fourth support 64 are fixed to the draft base 50.
[0088] Next, an apron traversing apparatus 40 that traverses the bottom apron belt 57 within a predetermined stroke will be described below.
[0089] The apron traversing apparatus 40 is arranged on the draft base 50. The apron traversing apparatus 40 includes an arm member (a traversing member) 41 and a motor (a drive) 43.
[0090] One arm member 41 is arranged for two bottom apron belts 57. The arm member 41 is an elongate plate-shaped member that extends in the roller axial direction. The arm member 41 may be formed from two parts joined together. As shown in the drawings, such as FIG. 7, a long and narrow space that extends in the roller axial direction is formed between the supporting member 62a and the rotary housing 62b of the second support 62. The arm member 41 is inserted into this space with its thickness direction oriented in the fiber traveling direction. The arm member 41 is supported by the supporting member 62a in such a way that the arm member 41 can slide in the roller axial direction.
[0091] As shown in FIG. 9, two fulcrum members 82 are arranged side by side on one supporting member 62a. The two fulcrum members 82 constitute a slide guiding portion that guides the bottom apron belt 57 in the traverse direction. Each of the fulcrum members 82 is a short cylindrical member with a ring groove formed on its outer periphery. The width of the ring groove is approximately equal to the thickness of the arm member 41. Each fulcrum member 82 is supported in such a way that it can rotate with respect to the supporting member 62a. The direction in which the two fulcrum members 82 are aligned coincides with the roller axial direction. Four elongated holes 47 are formed through the arm member 41. Each of the elongated holes 47 extends in the roller axial direction. The width of the elongated hole 47 is approximately equal to the diameter of the fulcrum member 82 at the position where the ring groove is formed. The portion of each fulcrum member 82 at which the ring groove is formed is inserted into the elongated hole 47. Accordingly, the fulcrum members 82 can guide the arm member 41 so that it moves along the roller axial direction.
[0092] A large-diameter portion of the fulcrum member 82 is so configured that it can be separated from the portion with the ring groove by a suitable mechanism. Accordingly, the portion of the arm member 41 with the elongated hole 47 can be inserted into the ring groove of the fulcrum member 82.
[0093] One longitudinal end of the arm member 41 protrudes from the second support 62 in a direction away from the line of symmetry L1. This protruding portion is located below the tensor bar 56. An action portion 42 is formed on the protruding portion of the arm member 41. The action portion 42 is a recess which opens upward. Similarly, another action portion 42 is formed on the other end of the arm member 41. The width of the recess accommodates the width of the bottom apron belt 57. The bottom apron belt 57 which is looped around the middle bottom roller 52 and the tensor bar 56 passes through the recess.
[0094] By reciprocating the arm member 41 in the roller axial direction, the two bottom apron belts 57 can be reciprocated in the roller axial direction via the two action portions 42. Accordingly, the bottom apron belt 57 can be moved periodically with respect to the fiber bundle path. As a result, the bottom apron belt 57 is less prone to wear and thus the frequency of the maintenance such as replacing the bottom apron belt 57 can be reduced.
[0095] As shown in the drawings such as FIG. 9, one motor 43 is arranged for two bottom apron belts 57. The motor 43 is arranged between the second support 62 arranged in a pair. The housing of the motor 43 is fixed to the draft base 50 via a motor bracket 44 that is an L-shaped member in a side view.
[0096] The output shaft of the motor 43 is arranged substantially parallel to the fiber traveling direction. An eccentric cam 45 is fixed to the output shaft of the motor 43. An elongate cam hole 46 that extends in the vertical direction is formed in the center of the arm member 41 in the longitudinal direction. The eccentric cam 45 is inserted into the cam hole 46. In this manner, a cam mechanism is formed.
[0097] When the motor 43 operates, the eccentric cam 45 rotates. This rotational motion is converted into the reciprocal motion of the arm member 41 in the roller axial direction through the cam hole 46. Accordingly, the two bottom apron belts 57 can be traversed.
[0098] While being supported by the four fulcrum members 82, the arm members 41 reciprocates integrally. If even one of the four fulcrum members 82 is misaligned, resistance occurs and the reciprocating movement cannot be smoothly performed. This can make the motor 43 to lose steps or can result in the increase of the energy consumption. As shown in the drawings such as FIG. 7, the bottom apron belt 57 travels diagonally with respect to the action portion 42 of the arm member 41. If the arm member 41 is misaligned (especially, misaligned in the direction of drafting), a failure such as coming-off of the bottom apron belt 57 from the action portion 42 can easily occur.
[0099] In this regard, in the present embodiment, all of the four fulcrum members 82 are attached to the supporting member 62a which is immovable with respect to the draft base 50, not to the rotary housing 62b. As a result, the reciprocating movement of the arm member 41 can be performed accurately and smoothly because the positional accuracy of the fulcrum members 82 is improved. Therefore, failures such as coming-off of the bottom apron belt 57 from the action portion 42 can be reduced.
[0100] As shown in the drawing such as FIG. 6, a bracket 83 is fixed to a surface of an upper portion of the rotary housing 62b, the surface being located on the upstream side in the fiber traveling direction. The bracket 83 extends in a direction away from the line of symmetry L1 and a condenser 58 is fixed to its end portion.
[0101] As described above, the condenser 58 is indirectly fixed to the rotary housing 62b. Since the middle bottom roller 52 is supported by the rotary housing 62b as described above, positional accuracy of the condenser 58 with respect to the middle bottom roller 52 can be improved.
[0102] The drafting apparatus 5 includes a draft roller assembly 5p with the draft base 50 to which more than one component is attached. The draft roller assembly 5p includes the draft base 50, the rotary housing 62b, the bearing 71, the middle bottom roller 52, and the tensor bar 56.
[0103] As described above, the draft roller assembly 5p of the present embodiment includes the draft base 50, the rotary housing 62b, the bearing 71, the middle bottom roller 52, and the tensor bar 56. The through hole 70 is formed through the rotary housing 62b. The bearing 71 is inserted into the through hole 70. The middle bottom roller 52 is rotatably supported by the bearing 71. The tensor bar 56 guides the bottom apron belt 57. The rotary housing 62b is rotatable with respect to the draft base 50. The rotation of the rotary housing 62b with respect to the draft base 50 changes the distance between the rotary housing 62b and the tensor bar 56.
[0104] Accordingly, the distance between the middle bottom roller 52 and the tensor bar 56 can be smoothly changed by rotating the rotary housing 62b.
[0105] The draft roller assembly 5p of the present embodiment includes the bottom apron belt 57 that is looped around the middle bottom roller 52 and the tensor bar 56.
[0106] Accordingly, the tension of the bottom apron belt 57 can be smoothly adjusted by rotating the rotary housing 62b.
[0107] The draft roller assembly 5p of the present embodiment includes the biasing spring 73 that biases (urges) the rotary housing 62b to one side in the rotational direction.
[0108] Accordingly, the rotary housing 62b can be rotated by the force of a predetermined magnitude by using the biasing spring 73 in the direction to stretch the bottom apron belt 57.
[0109] In the draft roller assembly 5p of the present embodiment, the rotary housing 62b is rotatable about the shaft member 66 with respect to the draft base 50. The biasing spring 73 is a spring attached to the shaft member 66.
[0110] Accordingly, the rotary housing 62b can be biased to one side in the rotational direction with a simple configuration.
[0111] In the draft roller assembly 5p of the present embodiment, the magnitude of the spring force is adjustable by changing the position to which the biasing spring 73 is fixed among the first recesses 75.
[0112] Accordingly, the tension applied to the bottom apron belt 57 can be changed according to the situation.
[0113] The draft roller assembly 5p of the present embodiment includes the supporting member 62a and the fixing arm 72. The supporting member 62a protrudes from the draft base 50. The fixing arm 72 is fixed to the supporting member 62a. The tensor bar 56 is fixed to the fixing arm 72.
[0114] Accordingly, the tensor bar 56 can be fixed at an accurate position.
[0115] The draft roller assembly 5p of the present embodiment includes the angle fixer 85 that fixes the rotational angle of the rotary housing 62b.
[0116] Accordingly, the positional relation between the tensor bar 56 and the middle bottom roller 52 can be reliably maintained.
[0117] In the draft roller assembly 5p of the present embodiment, the angle fixer 85 includes the angle fixing screw 79 that is fixed in a direction parallel to the rotational axis of the rotary housing 62b.
[0118] Accordingly, the rotary housing 62b can be prevented from rotating unintentionally when fixing the angle of the rotary housing 62b using the angle fixing screw 79.
[0119] The draft roller assembly 5p of the present embodiment includes the condenser 58 that bundles the fiber bundle 10. The condenser 58 is fixed to the rotary housing 62b.
[0120] Accordingly, the positional accuracy of the condenser 58 with respect to the middle bottom roller 52 can be improved. Thus, the quality of drafting of the fiber bundle 10 is improved.
[0121] The draft roller assembly 5p of the present embodiment includes the restricting pin 81 that restrict the rotary housing 62b from rotating in a direction away from the tensor bar 56 at an angle greater than a predetermined angle.
[0122] Accordingly, the ease of assembly can be improved.
[0123] In the draft roller assembly 5p of the present embodiment, two fiber bundle paths are formed, the respective fiber bundle paths being a path along which the fiber bundle 10 can travel. The draft roller assembly 5p includes a pair of the rotary housings 62b, a pair of the middle bottom rollers 52, and a pair of the tensor bars 56 for the two fiber bundle paths. The angle fixer 85 that fixes the rotational angle of the rotary housing 62b is arranged for each of the rotary housings 62b. The angle fixer 85 is located farther from a middle position between the two fiber bundle paths (the position of the line of symmetry L1) than the rotary housing 62b.
[0124] Accordingly, the angle fixer 85 can be easily accessed from outside. Thus, ease of adjusting the position of the middle bottom roller 52 is improved.
[0125] The drafting apparatus 5 of the present embodiment includes the draft base 50, the rotary housing 62b, the bearing 71, the middle bottom roller 52, and the tensor bar 56. The through hole 70 is formed through the rotary housing 62b. The bearing 71 is inserted into the through hole 70. The middle bottom roller 52 is rotatably supported by the bearing 71. The tensor bar 56 guides the bottom apron belt 57. The rotary housing 62b is rotatable with respect to the draft base 50. The rotation of the rotary housing 62b with respect to the draft base 50 changes the distance between the rotary housing 62b and the tensor bar 56.
[0126] Accordingly, the distance between the middle bottom roller 52 and the tensor bar 56 can be smoothly changed by rotating the rotary housing 62b.
[0127] The drafting apparatus 5 of the present embodiment includes the supporting member 62a and the fixing arm 72. The supporting member 62a protrudes from the draft base 50. The fixing arm 72 is fixed to the supporting member 62a. The tensor bar 56 is fixed to the fixing arm 72.
[0128] Accordingly, the positional accuracy of the tensor bar 56 is improved.
[0129] The fixing arm 72 may be fixed to the first support 61 instead of the second support 62. In this configuration, the fixing arm 72 corresponds to the installed member. The fixing arm 72 may be integrally formed with the first support 61.
[0130] Also in this case, the positional accuracy of the tensor bar 56 can be improved.
[0131] The drafting apparatus 5 of the present embodiment includes the supporting member 62a, the first support 61, and the front bottom roller 51. The supporting member 62a rotatably supports the rotary housing 62b. The first support 61 is integrally formed with the draft base 50. The front bottom roller 51 is arranged downstream of the middle bottom roller 52 in the fiber traveling direction and is supported by the first support 61. The supporting member 62a is detachably fixed with respect to the draft base 50.
[0132] Accordingly, the maintenance around the rotary housing 62b can be easily performed.
[0133] The drafting apparatus 5 of the present embodiment includes the traversing apparatus 21 that traverses the bottom apron belt 57. The bottom apron belt 57 is looped around the middle bottom roller 52 and the tensor bar 56. The arm member 41 of the traversing apparatus 21 is positioned with respect to the supporting member 62a.
[0134] Accordingly, since the positional accuracy of the arm member 41 with respect to the bottom apron belt 57 is improved, the smooth traversing motion of the arm member 41 can be achieved.
[0135] In the drafting apparatus 5 of the present embodiment, two fiber bundle paths are formed, the respective fiber bundle paths being a path along which the fiber bundle 10 can travel. The drafting apparatus 5 includes a pair of the rotary housings 62b, a pair of the middle bottom rollers 52, and a pair of the tensor bars 56 for the two fiber bundle paths. The angle fixer 85 that fixes the rotational angle of the rotary housing 62b is provided for each of the rotary housings 62b. The angle fixer 85 is located farther from a middle position between the two fiber bundle paths than the rotary housing 62b.
[0136] Accordingly, the angle fixer 85 can be easily accessed from outside. Thus, the position of the middle bottom roller 52 can be easily adjusted.
[0137] The spinning machine 1 of the present embodiment includes the drafting apparatus 5, the air spinning apparatus 6, and the winding apparatus 9. The drafting apparatus 5 includes the draft roller assembly 5p. The air spinning apparatus 6 forms the yarn 15 by applying the swirling airflow on the fiber bundle 10 drafted by the drafting apparatus 5. The winding apparatus 9 winds the yarn 15 formed by the air spinning apparatus 6 into the package 18.
[0138] Accordingly, the spinning machine 1 that can displace the middle bottom roller 52 smoothly for maintenance or the like can be achieved. As a result, the quality of the yarn 15 formed by the spinning machine 1 is improved.
[0139] Although the preferred embodiment of the present invention has been described above, the above-described configuration can be modified, for example, as follows. Such a modification may be made singularly or made in combination with any other modifications.
[0140] The shaft member 66 may be extended to protrude from the supporting arm 68 and the biasing spring 73 may be arranged at this extended portion of the shaft member 66. In this configuration, the biasing spring 73 is arranged, for example, farther from the line of symmetry L1 than the rotary housing 62b.
[0141] Instead of the torsion coil spring, a compression spring, for example, may be used as the biasing spring 73. The compression spring may be arranged, for example, between the supporting member 62a and the rotary housing 62b.
[0142] A biasing spring may be arranged on a jig that is used for adjusting the tension of the bottom apron belt 57 and is detachable with respect to the drafting apparatus 5 (the draft roller assembly 5p). By loosening the angle fixing screw 79 with the jig attached to the second support 62, the rotary housing 62b can be rotated by the action of the biasing spring of the jig with respect to the supporting member 62a. After that, the angle fixing screw 79 is tightened. In this configuration, since the biasing spring 73 on the second support 62 can be omitted, the number of the components in the drafting apparatus 5 (the draft roller assembly 5p) can be reduced.
[0143] As shown in a modification in FIG. 10, the orientation of the angle fixing screw 79 may be changed to be perpendicular to the roller axial direction. In the description of the modification shown in FIG. 10, the components identical or similar to those of the above-described embodiment may be marked with the same reference sings in the drawings and the description thereof may be omitted. An angle fixer 85x of the modification shown in FIG. 10 includes an adjusting plate 77x. The adjusting plate 77x is arranged between a pair of a supporting arms 68 and fixed to the bottom surface of a cylindrical portion 67 of a rotary housing 62b. A supporting member 62a includes a tubular portion 84 for supporting a shaft member 66. The adjusting plate 77x is arranged to cover the outside of the tubular portion 84. A threaded hole 78x is formed through the adjusting plate 77x and an angle fixing screw 79 is attached to the threaded hole 78x. The distal end of the angle fixing screw 79 makes contact with the outer peripheral surface of the tubular portion 84.
[0144] The adjusting plate 77x integrally rotates with the rotary housing 62b. When the angle fixing screw 79 attached to the adjusting plate 77x is loosened, the distal end of the angle fixing screw 79 separates from the outer peripheral surface of the tubular portion 84 so that the rotary housing 62b becomes rotatable. When the angle fixing screw 79 is tightened, the distal end of the angle fixing screw 79 makes contact with the tubular portion 84 strongly so that the rotary housing 62b can be fixed such that it cannot rotate.
[0145] The first support 61 may be configured as a separate component from the draft base 50.
[0146] Instead of the guide hole 80 and the restricting pin 81, the range of the rotational angle of the rotary housing 62b may be restricted, for example, by forming a projecting portion on the supporting arm 68. In this configuration, when the rotary housing 62b attempts to rotate more than a predetermined angle, the projecting portion makes contact, for example, with a suitable portion of the supporting member 62a and the rotation is restricted.
[0147] The adjusting hole 78 and the angle fixing screw 79 may be omitted.
[0148] The guide hole 80 and the restricting pin 81 may be omitted.
[0149] The condenser 58 does not have to be positioned with respect to the second support 62. For example, the condenser 58 may be fixed to the draft base 50.
[0150] A key groove along the roller axial direction may be formed on the top surface of the draft base 50, a key along the roller axial direction may be fixed to the bottom surface of the supporting member 62a, and the supporting member 62b may be attached to the draft base 50 with the key joint. In this case, it is easier to arrange the front bottom roller 51 and the middle bottom roller 52 to be precisely parallel.
[0151] The apron traversing apparatus 40 may be omitted.
[0152] In the drafting apparatus 5 and the draft roller assembly 5p, the two draft bottom roller groups 5a may be asymmetrically arranged. The drafting apparatus 5 and the draft roller assembly 5p may include only one draft bottom roller group 5a. In this case, the draft cradle 90 supports the draft top roller group 5b of one spinning unit 2.
[0153] In the above-described embodiment, each apparatus is so arranged that the yarn 15 supplied from the upper side is wound at the lower side in the direction of the machine height. However, each apparatus may be so arranged that the yarn 15 supplied from the lower side is wound at the upper side.
[0154] In the above-described embodiment, the yarn 15 is drawn out of the air spinning apparatus 6 by the yarn storage roller 23. However, the yarn 15 may be drawn out of the air spinning apparatus 6 by a delivery roller and a nip roller known to the public. In this case, at least one of the yarn storage roller 23, a mechanical compensator, or a suction slack tube may be arranged downstream of the delivery roller and the nip roller.
[0155] Although, in the above-described embodiment, the spinning machine 1 includes the yarn joining cart 30, at least one apparatus related to yarn joining may be arranged in each spinning unit 2. The method of yarn joining is also not limited to using the yarn joining apparatus 31 and the spinning machine 1 may join the yarn by piecing. , Claims:We claim:

1. A draft roller assembly (5p) comprising:
a base member (50);
a housing (62b) through which a through hole (70) is formed;
a bearing (71) that is inserted into the through hole (70);
a draft roller (52) that is rotatably supported by the bearing (71); and
a belt guide member (56) that guides an apron belt (57),
wherein the housing (62b) is rotatable with respect to the base member (50), and
wherein rotation of the housing (62b) with respect to the base member (50) changes a distance between the housing (62b) and the belt guide member (56).

2. The draft roller assembly (5p) as claimed in claim 1, comprising the apron belt (57) that is looped around the draft roller (52) and the belt guide member (56).

3. The draft roller assembly (5p) as claimed in claim 1 or 2, comprising a biasing member (73) that biases the housing (62b) to one side in a rotational direction.

4. The draft roller assembly (5p) as claimed in claim 3, wherein the housing (62b) is rotatable about a rotary shaft (66) with respect to the base member (50), and
wherein the biasing member (73) is a spring (73) attached to the rotary shaft (66).

5. The draft roller assembly (5p) as claimed in claim 4, wherein a magnitude of a spring force is adjustable by changing a position to which the spring (73) is fixed.

6. The draft roller assembly (5p) as claimed in one of claims 1 to 5, comprising:
a first member (62a) that protrudes from the base member (50); and
a second member (72) that is fixed to the first member (62a),
wherein the belt guide member (56) is fixed to the second member (72).

7. The draft roller assembly (5p) as claimed in one of claims 1 to 6, comprising an angle fixer (85) that fixes a rotational angle of the housing (62b).

8. The draft roller assembly (5p) as claimed in claim 7, wherein the angle fixer (85) includes a fixing member (79) that is fixed in a direction parallel to a rotational axis of the housing (62b).

9. The draft roller assembly (5p) as claimed in claim 8, comprising:
a fiber bundle bundling member (58) that bundles a fiber bundle (10),
wherein the fiber bundle bundling member (58) is fixed to the housing (62b).

10. The draft roller assembly (5p) as claimed in claim 6, comprising a stopper (81) that restricts the housing (62b) from rotating in a direction away from the belt guide member (56) at an angle greater than a predetermined angle.

11. The draft roller assembly (5p) as claimed in one of claims 1 to 10, wherein
two fiber bundle paths are formed, the respective fiber bundle paths being a path along which the fiber bundle (10) can travel,
wherein a pair of the housings (62b), a pair of the draft rollers (52), and a pair of the belt guide members (56) are provided for the two fiber bundle paths,
wherein an angle fixer (85) that fixes a rotational angle of the housing (62b) is provided for each of the housings (62b),
wherein the angle fixer (85) is located farther from a middle position between the two fiber bundle paths than the housing (62b).
12. A drafting apparatus (5), comprising:
a base member (50);
a first housing (62b) through which a through hole (70) is formed;
a bearing (71) that is inserted into the through hole (70);
a first draft roller (52) that is rotatably supported by the bearing (71); and
a belt guide member (56) that guides an apron belt (57),
wherein the first housing (62b) is rotatable with respect to the base member (50), and
wherein rotation of the first housing (62b) with respect to the base member (50) changes a distance between the first housing (62b) and the belt guide member (56).

13. The drafting apparatus (5) as claimed in claim 12, comprising:
a first member (62a) that protrudes from the base member (50); and
a second member (72) that is fixed to the first member (62a),
wherein the belt guide member (56) is fixed to the second member (72).

14. The drafting apparatus (5) as claimed in claim 12, comprising:
a second draft roller (51) that is arranged downstream of the first draft roller (52) in a fiber traveling direction;
a second housing (61) that rotatably supports the second draft roller (51); and
an installed member (72) that is fixedly provided on the second housing (61),
wherein the belt guide member (56) is fixed to the installed member (72).

15. The drafting apparatus (5) as claimed in claim 12, comprising:
a supporting member (62a) that rotatably supports the first housing (62b);
a second housing (61) that is integrally formed with the base member (50); and
a second draft roller (51) that is arranged downstream of the first draft roller (52) in a fiber traveling direction and is supported by the second housing (61),
wherein the supporting member (62a) is detachably fixed with respect to the base member (50).

16. The drafting apparatus (5) as claimed in claim 15, comprising
a traversing apparatus (21) that traverses the apron belt (57) that is looped around the first draft roller (52) and the belt guide member (56) ,
wherein a traversing member (41) of the traversing apparatus (21) is positioned with respect to the supporting member (62a).

17. The drafting apparatus (5) as claimed in one of claims 12 to 16, wherein
two fiber bundle paths are formed, the respective fiber bundle paths being a path along which the fiber bundle (10) can travel,
wherein a pair of the first housings (62b), a pair of the first draft rollers (52), and a pair of the belt guide members (56) are provided for the two fiber bundle paths,
wherein an angle fixer (85) that fixes a rotational angle of the first housing (62b) is arranged for each of the first housings (62b), and
wherein the angle fixer (85) is located farther from a middle position between the two fiber bundle paths than the first housing (62b).

18. A spinning machine (1) comprising:
a drafting apparatus (5) that includes the draft roller assembly (5p) as claimed in any one of claims 1 to 11 or the drafting apparatus (5) as claimed in any one of claims 12 to 17;
a spinning apparatus (6) that forms a yarn (15) by applying swirling airflow on a fiber bundle (10) drafted by the drafting apparatus (5); and
a winding apparatus (9) that winds the yarn (15) formed by the spinning apparatus (6) into a package (18).