CA1050512A - Method and apparatus for automatically changing bobbins and winding yarn continously - Google Patents

Abstract

AN IMPROVEMENT OF METHOD AND APPARATUS FOR AUTOMATICALLY

CHANGING BOBBINS AND WINDING YARN CONTINUOUSLY

ABSTRACT OF THE DISCLOSURE

An improved method and apparatus for automatically chang-ing bobbins and winding yarn continuously in a winding or taking-up apparatus provided with a rotatable turret whereon a pair of bobbin holders are rotatably mounted. Each bobbin utilized for this apparatus is provided with a yarn catching groove formed on a peripheral portion thereof. When the bobbin exchanging operation is carried out, the turret is turned in a direction opposite to the rotatational direction of fresh and full packaged bobbins held by the corresponding bobbin holders so that the yarn passed through a traverse guide of the apparatus is aligned with the yarn catching groove of the fresh bobbin whereby the yarn is engaged with the above-mentioned yarn catching groove.

Description

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BACKGROUND OF THE INVENTION
This invention relates to a method for automatically changing bobbinsand winding yarns continuously threrupon and an apparatus for workir~ this method. Mor~ particularly the invention relates to a revolving-type winding method in which a yarn is continuously wound on bobbins held on bobbin holders rotatably mounted on a rotatable turret while automatically replacing a f~lly wound bobbin with an empty bobbin, and to an apparatus for practising this winding method.
In conventional continuous yarn winding:~apparatuses including an automatic b~bbin exchange mechanism, for example, as is disclosed in the specification of British Patent No. 1,332,182, a yarn to be transferred from a full bobbin to an empty bbbbin is caught by yarn-guidirlg fitt-ings fixed to the end of a bobbin holder for holding a bobbin thereon, or by thread-guiding fittings held on a bobbin holder wlth a bobbin.
When the bobbln exchange is conducted by using such conventional apparatus, a yarn wraps around the yarn-guid-lng fittings in a complicated manner and such operations~
as ~the treatment of the yarn end after doffing of a full bobbin;and the dismounting and mounting of yarn-guiding , : :
;fittings become complicated. Accordingly, various difficulties are involved in automating treatments subse-quent to the doffing step and, if these treatments are made automatic, equipment costs are tremendously high so that no economical advan~ages can be attained.
For overcoming these difficulties,it was~proposed to form a yarn-catching circular groove on a bobbin. However when bobbins having a groove on the periphery thereof are employed, the ratlo ofsuccess in catching the yarn end is very low, resulting in reduction of productivity and oper-:. . ::ational

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efficiency. Especially when i-t is intended to perform the bobbin exchange automatically, this defect becomes a serious obstacle.
As a result of out investigations made to clarify why the ratio of success in catching the yarn end is low in the method using bobbins having a circular groove formèd on the periphery thereof, we found that since the yarn is main-tained under excessive tension when it is about to be en-gaged wi-th the circular groove of a bobbin, it is very difficult for the bobbin to hold the yarn by the circular groove, and that since the yarn is not properly aligned with the circular groove, the yarn cannot be engaged with said circular groove. ~:
A yarn-guide or the like may be used for aligning a yarn with a circular groove, in order to avoid said prob-lem. However, if a yarn-guide or the like is used, the yarn is relaxed in the vicinity of the bobbin. Since a yarn in the relaxed state has a property that i* i$ likely to wrap around a rotary member disposed in the vicinity thereof, for example, a roller or the like, winding of the relaxèd yarn on a roller located in thev~cinity of the yarn passage is enhanced as wèll as winding of the yarn on the b~bb1n~. Further, properly alignment of the yarn wtth the circular groove on~a bobbin cannot be ob-tained~even if~the utmost efforts are made using the con- ;
ventional method, beca~use limitations areimpOsed on the precision of positionin$ the groove and the yarn is inevit-ab].y unstable when travelling. ; i : 1 : ~ : . . .
,~ ~; It lS a primary object of th1s invention to provide ~-a method and apparatus for automatically changing bobbins and winding yarn continuously thereupon, in which the above-mentioned defects and disadvantages involved in con-ventional techniques can be overcome, namely such method and apparatus ~ 3 _ ~ L()5~51Z
in which full bobbins, where the yarn ends can easily be handled as steps subsequent to doffing, can be obtained and exchange of bobbins can be done very smoothly without trouble.
In the method of this invention for automatically changing bobbins and winding yarn continuously thereupon, a yarn catching groove is formed at the end of a bobbin instead of yarn~guiding fittings used for catching the yarn in the conven-tional techniques. On exchange of bobbins a turret is rotated in a direction opposite to the rotational direction of the bob-bins, so that the yarn is aligned with the groove and engagedwith the grooved bobbin.
According to the present invention, in an apparatus for automatically changing bobbins and winding a yarn thereupon continuously which comprises a turnable turret on which a plur-ality of bobbin holders for holdi.ng bobbins are rotatably moun-ted, means for rotating bobbins held on said bobbin holders, and ., .
traverse means for traversing said yarn upstream of said bobbin holders in the axial direction thereof, means forturning said turret to alternate exchange positions of bobbins held on said ~ 20 bobbin hoIders between a winding position and a standby position, J~ there is provided the improvement wherein said bobbin rotating ~means comprises a motor,~ a friction roller driven by said motor ~ ~ for driving said bobbin held on said~bobbin holders when the ;~ peripheral surface of said bobbin contacts with~said friction roller, a power transmission means for transmitting a driving ~power from said motor to said friction roller, auxiIiary means for driving said bobbin for contacting said bobbin with said ~riction roller, and comprising an arm swingably mounted on a shaft of said turret, an auxiliary roller rotatably mounted on :

3~ said arm, a further motor disposed on a machine frame, and a power transmission means for transmitting driving power of said , ,~ .

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further motor to said frict~on.rollex, and ~herein.said turret -turning means compr~ses ~ea~s for turning said turret in a direc-tion opposite to the rotational direction of said bobbins at the time o b~bbin exchange, a guide disposed upstream of said yarn traverse means for disengaging said yarn from said yarn traverse means, and a yarn catching groove foxmed at a peripheral portion of each bobbin.
An apparatus of this invention for automatically chan- -g~ng bobbins and winding yarn continuously thereupon, which is used for practising the aforesaid method smoothly and assuredly, comprises a turnable turret on which a plurality of bobbin holders for holding bobbins are rotatabl~ mounted, means for rotating the bobbins held on said bobbin holders, and traverse means for trav-ersing said yarn upstream of said~ bobbin holders in the axial direction thereof, means for turning said turret to alternate exchange positions of bobbins he].d on said.bobbin holders between a winding position and a standby position, an improvement com-prising T~n combination, said turret turning means being capable , of turning said turret in a direction opposite to the rotational direction of said bobbins, a guide disposed upstream of said yarn : tràverse means for disengaging said yarn from said yarn traverse ~,~ means, and a yarn catching groove formed at a peripheral portion of each bobbin.
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~: ~BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view illustrating an embodiment i .. ~of the apparatus for practising the method of this invention .~ .

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for automatically changing bobbins and continuously wind-ing a yarn.
Figs. 2 through 5 are views illustrating an embodiment of the method of this invention where bobbins are exchanged and a yarn is wound by using the apparatus shown in Fig.

1.
Fig. 5 is a front view of a tandem-type apparatus for automatically changing bobbins and winding yarns continu-ously according to this invention.
Fig. 7 is a view showing the right side of the appara-~tus shown in Figo 6.
Fig. 8 is a view showing the section taken along the 'i line VIII-VIII in Fig. 6.
Fig. 9 is an air pressure circuit diagram of an actu-at~r ~or rotating a turret.
Figs. lOA to lOD are views illustrating the operation of the tandem-type apparatus shown in Fig. 6.
DETAILED DESCRIPTION OF THE INVENTION
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The method of this invention for automatically chang-ing bobbins and continuously winding a yarn will now be , .
illustrated by reference to the apparatus of this invention ~ -illustrated in Figs. 1 to 5.
Referring to Fig. 1, a yarn 1 is traversed by a yarn gulde 3 of a traverse device 2, passed through a frlction ~ ~
roller 4, and wound on a bobbin 7 or 8 pressed by said ~ -roller 4 rotated at a certain speed to form a package. The traverse device 2 and friction roller 4 are carried on a slide b~lock (not shown), capable of rectilinear vertical movement and on the traverse device 2, a~yarn disengaging guide 12 is swingably pivoted on bearings lla and llb, ~ ;
formed on brackets lOa and lOb. A yarn gathering guide 14 is slidably attached to ~uide bars 13a and .' ' ' ' ',:~ .

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13b, mounted on the back surface of the guide 12. The guide bar 13a also acts as a swinging shaft for the yarn disen-gaging guide 12, and a sliding cylinder 16 is attached to the top end of the guide bar 13a through a lever 15. This cylinder 16 is actuated by air pressure. Further, a yarn gathering cylinder 17, which is actuated by air pressure, is a-ttached to the yarn gather guide 14.
A turret 9 is rotatably disposed on a shaft 9a and is rotated by an actuator (not shown). Bobbin holders 5 and 6 are rotatably mounted on the turret 9 and bobbins 7 and ',' 8 are held on the bobbin holders 5 and 6. The turret 9 is rotated in the clockwise direction indicated by an arrow ~
Xl in Fig. l, and the rotational direction of the turret 9 - -is opposite to the rotational direction of the bobbin ~, holders 5 and 6 (the counterclockwise directions shown by , an arrow X2 in Fig. l). Yarn catching grooves 7a and 8a are formed on~,ends of the bobbins 7 and 8 on the peripher-ies thereof. ~,' Guides 20a and 20b are so disposed that the guide ,' 20a or 20b on the traverse device side can be projected ,~
to the vicinity of the yarn catching groove 7a or 8a of ~' , ~ .
the bobbin 7 or~8 respectively, ~rom the position of the ;'-' turre~t 9~by means of a cylinder 21 or 2? actuatsd by air '`
pressure. -Ths sxchange of bobbins and the windlng of a yarn are conducted ln the following manner by u~sing the apparatus -having the a-foresaid structure. ' , '' In the state shown in Fig. l, a yarn is transferred from~a full bobbln to an emp,ty bobbin 7 and the full bobbin is doffed. In this state, winding is atarted and when the yarn is fully wound on the bobbiny7, a full-bobbin signal is given by a timer (not shown) or the like and ths start-ing of the bobbin 8 is . .
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initiated by an auxiliary roller (not shown) in the manner described in the explanation of the second emkodiment of the present invention. Then, the turret 9 is rotated in the clockwise direction Xl in Fig. 2 by an actuator (not shown) and a fully wound package P in Fig. 2 on the bobbin 7 rotated while in contact with the surface of the friction roller 4. When the package P æparates from the friction roller 4 and an empty bobbin falls in contact with the friction roller 4 (see Fig. 4), the yarn disengaging guide 12 is swung to the direction X4 in Fig. 4 and the yarn 1 is disengaged from the yarn guide 3. Since the yarn tends to move to~rd a passage having lower yarn tension, the yarn 1 runs along a passage from the fulcrum of the -tra~erse device to the center of the traverse motion device 2. The yarn gathering guide 14 is moved in the direction X3 in Fig. 5 and simultaneously, the guide 20a is moved in the direction X
in Fig. 5. Accordingly, when the yarn 1 is aligned with the yarn catching -~ groove 8a of the bobbin 8, as shown in Figs. 4 and 5, the yarn 1 is led to the fully wound package P and a bulge of wound yarn .
23 is formed on the package. Further, when the yarn 1 is aligned with the `` yarn catching groove 8a of the bobbin 8 by the yarn gathering guide 14, and the portion of the thread 1 extending from the ~20 friction roller 4 to the fully wound package P falls into contact : wlth~ the yarn catching groove 8a of the empty bobbin 8.
Since the rotational direction of the bobbin is the opposite of the moving direction of the yarn 1 and the empty bobbin a is rotated by the turret 9 in such a manner as will allow intrusion of the yarn 1, the yarn 1 is engaged with the ~;~ yarn~catching groove 8a of the empty bobbin 8 and yarn tension ; between the fully wound package P and the empty bobbin 8 increases, ~ whereby the yarn 1 is broken and winding on the empty bobbin 8 is ,~ initiated.
io When winding of the yarn 1 on the empty bobbin 8 is :' ' ` 7 1 [3S(~Sl~
initiated, the yarn gathering guide 14 is re-turned to the original position and, then the yarn disengaging guide 12 is returned to -the original position. At this point, a transfer -tail is formed on the empty bobbin 8 by means of the yarn gathering guide 14 and the yarn disengaging guide 12, and the yarn 1 is engaged with the yarn guide 3 of the traverse device 2 to initiate normal winding. In the same manner as described above, the yarn is continu-ously wound on bobbins while full bobbins are replaced with empty bobbins.
` In the foregoing embodiment, the guides 20a and 20b are mounted on the turret. It is possible to disposed the guides on the lower side of the traverse device 2 so that guides are pushed in between the bobbi~ 7 and 8. This modification is especially preferred for the so-called tan-dem-type apparatus in which two bobbins are held on one bobbin holder.
An embodiment where the method of this invention is , .
applied to a winding machine of the tandem type will now be described by reference to Figs. 6 through 10. For ! ~
facilitating understanding of` the description, members mentioned ln the foregoing embodiment are indicated by the same reference numerals.
Referring to Figs. 6 and 7, two slide shafts 23 extend-ing in the vertical dlrection are fixed to a machine f`rame ~22 and a slide block 25 is moved rectilinearly and verti-' ~ cally along the slide shafts 23 by a slide bearing 24.
~J, ~ The slide block 25 carries a traverse device Z having a pair of traverse guides 3 for traversing a yarn l in the traverse zone and a rotatable friction roller 4 connected .1 , .
to a drive motor (not~shown). A case 26 is provided witha bearing 27 supporting the friction roller 4. A pair of brackets 28 are mounted on the traverse device 2 to swing- ~-ably support a yarn disengaging guide 12 . ~ ~
:: ' extending in the traverse direction of the traverse guide 3 by means of a pin 28a. The top end of a rod 16a of a swinging cylinder 16 and the rear end 16b of the cylinder 16 are pinengaged with the yarn disengaging guide 12 and a bracket 2a disposed on the traverse device 2, respectivel~
When the rod 16a is proj,ected, the yarn disengaging guide 12 is swung so as -to cross the passage of the yarn 1 and disengages the running yarn 1 from the traverse guide 3.
A gyide 19 is fixed to the traverse device 25 to face -the yarn disengagi:ng guide 12 with the yarn lying therebetween The guide 19 has one V-shaped recess l9a in each traverse ,, zone. ~' A turrets 9 is rotatably supported on a shaft 9a, and mounts bobbin holders 5 and 6 rotatably. A circular ' groove S having a V-shaped section is formed on the peri-~,heral surface of a bobbin B in the vicinity of the end face thereof. Two bobbins are held on each of the bobbin holders 5 and 6. On the peripheral surface of the turret 9, a pair of positioning recesses 9b are formed at positi~s symmetrical to each other with respect to the shaft 9a.
A cylinder 30 is mounted on the machine frame 22 to move : .
~, forward and backward positioning pins 29, which are engaged ' with said recesses 9b.
A main cylinder 31 is mounted to support the slide bloak 25 thereon by means of a rod 32 in order to displace said ,~lide block in an upward or downward direction. A
compressed fluid is fed into the main cylinder 31 through ~;, ' a conduit (not shown) to push up the slide block 25. Feèd-: : .. :
ing~of the compressed fluid is controlled by a control ;-valve (not shown~ so that the slide block 25 is always~l~fted~
up with a certain force aginst the total weight of the-slide hlock 25 carrying thèreon the friction rollèr 4,~th-e trav-erse device 2,and:a motor driving these members. '' ~ ' ~ ,::, .:
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as well as the frictional force generated when -the slide ~ -block 25 slides along the slide shafts 23.
A contact pressure control device 33 including a pulley 35 and an eccentric cam 36 is mounted on a shaft 34 rotatably supported on the machine frame 22. Belts 39 and 40, the ends of which are connected to the slide block 25 and a rod 38 of an auxiliary cylinder 37, respec-tively, are hung on the pull~ey 35 and the eccentric cam 36, respectively, in directions reverse to each other.
The eccentric cam 36 is disposed so that as shown in Fig. 7, at initiation of winding, namely in the state where the friction roller 4 is directly in contact with the bobbin Bj~ the belt 40 separates from the point most distan*-from the shaft 34. When a compressed fluid ~s fed to the aux-iliary cylinder 37 through a conduit (not shown), the slide block 25 is pushed down against the pushing-up force of the main cylinder 31, whereby the friction roller 4 is urged toward the b~bbin B. As the diameter of the package wound on the bobbin B increases, the eccentr:ic cam 39 is rotated to reduce the above-mentioned contact pressure.
As is shown in Fig. 8, an actuator 42 is connected to the turret 9 through a so-called one-way clutch 41 for transmitting a rotation of one direction to one end of the shaft 9a. As is shown in Fig. 9, in the actuator 42, pis-tons 44~and 45 are fitted to a~cylinder 43 to form pressure chambers 46a and 46b. A compressed fluid such as compress~d air is caused to act on the~pressure chambers 46a and 46b alternately by means~of a~change-over valve 47, whereby the pistons 44 and 45 are caused to make reciprocating .
movement and rotate a pinion 49 engaged with a rack formed on a rod 48 connecting the pistons 44 and 45 . ~ :

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to each other. The rotary movement of the actuator 42 is transmitted to the turret 9 as a one-direction rotation, namely as the clockwise direction rotation indicated by the arrow Xl. This rotational direc-tion indicated by an arrow Xl is opposite to the rotational direction X2 of -the bobbin. Oil is filled in the pressure chamber 46b positioned on the exhaust side when the turret 9 is rotated in the direction Xl, and a speed controller 51 is disposed :
between the pressure chamber 46b and an auxiliary oil tank 50. The rotation of the turret-9 connected to the actuator 42 can be smoothly adjusted by controlling the opening of a throttle valve 52 of the speed controller 51.
In Flg. 8, an annular guide 53 is fitted to the peri-pheral surface of the turret 9 and is attached to the machine frame 22. The guide 53 has a cam groove 54 on the inner peripheral surface. The guide 53 may be divided into two portions for easier maintenance. Bobbin holder insert- ,-ing holes 9c are perforated in the turret 9 to receive therein slidlng cylinders 55 of the bobbin holders 5 and 6 so that'they can move in the axial direction. A pin 57 is screwed to the surface of the sliding cylinder 55 to sup-i , port~a~cam folIower 56 thereon to be inserted~ into the '' ~' ;
c'am~gi~oove~ 54.~A shaft 60 is positloned the inslde of the ,; ,, sli~dlng~cyli~nder 55 vla bearlngs 58 and 59.~ A head 61~for receivi,ng~a bobbin~B thereon~is~f~ixed to the top end of the ,' sha~ft;;~60~nd,a pulley 62 is fixed to the rear end of the shaft~ 60. With rotation of the turret 9, the cam groove ~
acts together with~ the cam follower 56; for moving~the bobbin ~ ,, holders~5 and 6 in the axlal directlon~toward the side of the~turret 9 and returning~them to their original posi- ~-tions agaln-A~rotary ~ctuator 63 is fitted to the turret 9, and a . ~: , , pinion 65 attached to the top énd of a rod 64 of the actu- ' '~ ator 63 - 11 ~ " ""' '; '~ ,: '''' .`~ , .: ' ~ ~ 50 5 ~ ~
is turned left or right by means of a compressed fluid. The pLnion 65 is engaged ~Jith teeth 67 formed on the rear end of an arm 66 pivoted swingably on the shaft 9a, and tlle arm 6G is : st~ng around the shaft 9a with rotation of the pinion 65. On the top end of the arm 6S, an auxiliary roller 68 is rotatably supported by means o~ a pin 69 and a bearing 70. A belt 73 is extended bet~een the auxiliary roller 68 and an intermediate - pulley 72 rotatably supported by a bearing 7.1~ ~ bélt 76 is extended bet~reen the intermediate pulley 72 and a pulley 75 connected to an auxiliary motor 74 fixed to the rnachine frame . 22. The rota-tion of the motor 74 is transmitted to the auxiliary rollsr 68 tllrou~h the belt 76, the intermediate pulley 72 and tl~e -~. . belt 73, and the bobbin holder 5 or 6 is rotated by the pressing of the auxiliary roller 68, to which rotation is given by the ro~ary actuator 63, against tlle pulley 62 located at the end of the bobbin holder 5 or 6.
~. brake device 77 for the bobbin holders comprises a i palr.of ~iscs ~0 actuated by a fluid pressure cylinder 78 and move~ alon~ a guide shaft 799 and a spring 81 adJusting the dlstance bet~een the discs 80 to adjust the degree of braking .~ by thè discs 80~ -,, .
~s sllown~in Figs. ~ and 7, a push-out cylinder 82 is ~ixed to the machine frame 22 to do~f a full bobbin from the ~'; bobbin holder and a push-out piece 84 is attached to a rod 83 ~25 of the push-out cylinder 82 so that the upper end of the push-~ ~ .
,i out piece 84 presses the end portion of the bobbin B~ h guide -~ 85 is disposed to pravent oscillating movement of the push-out piece 84.
Bobbin exchange and yarn winding conducted by using the appar~tus of this inven-tion havinO the above-mentioned ~ 12 -.

g l~OS12 ~itructure ~/ill now be described~
In the state sho~ n in E~igs 6 alld 7 9 a yarn 1 is ~round on a bobbin B held on the bobbin holder 5 while -the yarn 1 is tr&verse~. b~,r tlle travcrse ~uicle 3 of tho traversc devicc 2.
5 ~.Jhen the bobbin becomes full as sho~m in Figs 101~ and lOB, a full bobbin signal is given by a timer (not shown) or the lilce.
In response to this si~nal 9 the auxiliary motor 74 is turned on to initia-ce rotation oi the auxiliary roller 6~, and by the rotary actuator 63 the auxiliary roller 68 is caused to press 10 the pulley 62 of the bobbin holder 6 on l,~ich an empty bobbin B
is held, ~/hereby the rotation of the bobbin B i5 initiated Then, the cylinder ~0 is actuated to draw out the positioning :-~ pin. 29 frorn -the recess 9b and the turret 9 is rotatecl in the . clockl,rise direction (the direction indicatecl by an arrow ,~1) by the actuator ~2, ~Jhereupon the full bobbin on -the bobbin holder ~-5 and -the ernpiy bobbin on the bobbin holder 6 are rotated. :
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l..rith rol;ation of the turret 9, cam follc)wers 56 .nounted on the bobbill holc!ers 5 and 6 ancl cam grooves 54 formecl on the cams 53 ~' are :en~aged ~ith ea~h other and the bobbin holcler 6 carrying . .
20 the ernpty bobbin thereon is moved in the axial direction ttlle ., .
dlrection indicatecl b~ an arrow X3 in Fi.g 103). ht this point, the peripheral ~roove S of the enpty bobbin B held on the bobbin holder~ 6 slightly exceeds the recess l9a of the guide 19 and ls . : .
locatecl in l;he traverse zone OI the traverse guide 3 ~.rhen the 2g turret~9 i5~ further rotated, the full bobbln separates from the ' frictloll roller 4.~ Th6n, the~ auxiliary roller 68 ls switched .
, over ~from:the pulley 62 of the bobbin holder 6 carrying the ; ;-~ .
`` empty bobbin to:the pulley 62 of the:bobbin llolder 5 carrying the full. bobbi,~. When the turret 9 is further rotated, the empty bobbin falls into contact with the friction roller 4. A:Eter .:
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~ 05~S~L2 the yarn 1~ being wound on -the full bobbin ~rom the -traverse ; guide 3, has been placed in con-tact with the surface of the empty bobbin, the s~ing~lg cylinder lG is actuated in the direction indicated by an arrow Y.~ as sho~M in Fig lOC to swing the yarn disengagin~ guide 12. The yarn 1 is bent between the yarn disenga~in~ guide 12 and -the guide 19 as indicated by a t~lo-clot chain line in Fig. lOC. In this state9 ~rhen the yarn 1 is traversed by the traverse guide 3, the yarn 1 slides on the peripheral face of the guide 19 while in contact therewith and arrives at ancl falls into the recess 19a formed on the guide 19 . . .
~ Thus, tlle yarn 1 is released from the traverse guide ~ as . ~ .
: indicated by a solid line in Fig lOC, and a bulge of wound yarn is formed on the full bobbin at a position corresponcling to the recess 19a. While the turret 9 c`ontinues the rotation, the bobbin holder 5 carrying the empty bobbin is moved in a direction opposite to the above mentioned c~.irection, ancl the circular ~roove ~ ~ormed on ~he periphery o tlle empty bobbir.
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is shi~ted toward the yarn 1 being wound. I]hen the circular groove S i5 in ali ~nent with the yarn 1, since the rotational direction of the empty bobbin (the direction X2) is opposite to the moving direction of the yarn 1 and since the rotational ~: directlon of the~turret 9 (the direction X1) is opposite to the rotational~direction of the bobbin (the direction ~2~, the yarn 1 is allowed to move into the circular groove S of the empty ~.25 bobbLn S and is al~rays en~aeed l~rith this groove S. At this - mornent, yarn tension bet~reen the full bobbin and tlle empty bobbin increases, ~hereby the yarn l is cut c~nd winding of the yarn 1 on~the empty bobbin is initiated. Then, the auxiliary motor 7 is turned ofI, and the auxlliary roller 68 pre5sing the pulley 62 o~ the bobbin holder 5 carrying the full bobbin is stopped .. . .

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- 1~50S~2 and the movement of the pulley 62 is controlled by the br~ce device 77~ On the other hand, a transfer tail of several turnsJ
in general9 is formed on the end portion of the empty bo~bin while the bobbin holder 6 carrying -the empty bobbin is re-turned ; 5 to the normal windi~g position with the yarn 1 being ~roun~ thereon.
By feedin~ a compressed fluid to the cylinder 30 up to this moment, the positioning pin 29 is en~aged with the recess 9b, whereby the turret 9 is settled at the prescribed position, As soon as, or just before or after, the bobbin holder G
10 arrives at the normal ~inding position, the yarn disengag-ng guide 12 is returnecl to the original position by means of the swinging cylinder 15. Thus, the yarn 1 is released from the yarn disengaging ~uide 12 and the guide 19, and it travels along the thread passage crossing the traverse zone of the traverse 15 guide 3 and is engaged 'llth the traverse guide 3 to start the normal wincling.
~fter the full bobbin has been stopped, the full bobbin is doffed from the bobbin holder 5 by the push-out piece ~r fixe~ to the push-out cylinder 82, and an empty bobbin B is , `l 20~ donned on tlle bobbin holder 5 and is prepared for the next bobbin exchange.
As the traverse mechanism of the apparatus of this -~
invention, a belt traverse mechanism, a cam traverse mechanism or any of the other lcno~/n~traverse mechanisms can be emplo~/e~
~;~25 Cutt m g of the yarn~bet~Jeen the empty bobbin and the fuIl bobbin may be accomplished by using appropriate cutting means.
~lthougll tllo circular groove lS formed on the front side of the bobbin in the fore~oing embodiment, the circular groove may be formed on the frame side. In this case, the bobbin is shifted ~ 30 toward the front side at the time of bobbin exchange. Further, ', ' . .
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it is possible to allow the full bobbin and empty bobb~ to be in contact with the friction roller when they are exchanged, Furthermore, the bobbin drive system is not limited to the friction drive system using~ a friction roller as sho~Jn in the 5 foregoing embodiment, but it is possible to adopt the spindle system where the bo~oin holder is driven and rotated by a motor disposed coaxially ~Jith the bobbin holder. Although the sli~e block carryin~ thereon the iriction roller and the traverse device is moved rectlinearly in the vertical direction in the :
:10 foregoing embodiment~ such an arrangement may be made that the bobbin holder is moved in the horizontal clirection .insteacl of . the slide ~lock. ~-J In -the contact pressure control device 33 a counter wel~ht, a sprin~ or a torque motor may be employed instead of the ~15 cylinder 31 and/or the cylinder 37, . ~ ~ In the a~paratus of this invention, by virtue of the ; ~ ~eature that the rotational direction of the bobbin holder is opposite to the rotational direction of the turret c~nd the ~arn is runnin~ in the opposite direction whi].e in contact with .:-~20 the surface of the bobbin, at the time of the bob~in exchange ~ .
the yarn tension is slightly reduced upstream of ~he bobbin and the~runnin~ arn:comes to have a property such that it is readily :~ wound on the:bobbin, whereby the yarn is engaged ~ith the circular . ~ groove of tl~e bobbin with certainty an~ the ratio of success .,25 in the transfer is drastlcally improved, This reduction of the ;~ tension ~lS ~er~ slight and~:the degree of the tension reduction ~ .
,~: is not such that the running yarn is readily wound on rollers ,.
disposed upstream of the bobbin. Further, in the apparatus of l~. this inven~ion, since the yarn is engaged ~rith the circular i30 groove ~ormed on the periphery of the bobbin while the bobbin : - 16 _ ':

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5 ~ 2 holder is being moved in the axial direction so that the circular - groove e~cee~s tha recess Pormed on the guide, holding OI the yarn by the circular groove is done with certainty without beLn~ influellced by the unstable movement of the yarn or the processing precision of the groove. During the bobbin e~chan~e, -the yarn tension retains normal value so that no undue damage such as une~eness of dyeability occurs Moreover, s mce a transfer tail is formed simultaneously with the holding of tl~e yarn, no ercessive winding is caused Oll the bobbin, and treatments subsequenl to the doffin~ step can be performed very easily and the transfer tail is not ~isturbed by the excessive w~ldin~.
Still further in this invention, since no yarn guiding fittings are used, treatment of such fittings is unnecessaryand automatic ; handlin~ o~ ~obbins and packages subsequent to the doffin~
step can be preatly facilitated. In case such fittings are employed, in order to prevent detachment of the fittillgs at high spee~l rotation, the fittings are disposed at a closer . .~ . . , pOSitiOll to the mac'hine frame than that o~ bobbills, so -that f a trans~er tail can ~enerally be formed only on the frame side o~the bobbin~ In contrast, according to this invention, a f~ trans~er tail may bç formed on any optional side of the bobbin .
f and hence, it is possible to optionally select the direction f~ o~ ~rindin~ of the yarn on the bobbin and the position of the f-1;~ transfer t~il depencin~ on the use.
f 25 hs is apparf~nt fr~om the foregoin~ illustration, according .,,: ~ ~ , ..
to this invention, the ratio of success in the transfer o~^ the y8rn is greatly improved and the post treatments can be greatly faollitated. Accordin~ly, this invention ~al;es grea-t contri-butions to the improvçment of productlvlty.

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Claims (7)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an apparatus for automatically changing bobbins and winding a yarn thereupon continuously which comprises a turnable turret on which a plurality of bobbin holders for holding bobbins are rotatably mounted, means for rotating bobbins held on said bobbin holders, and traverse means for traversing said yarn up-stream of said bobbin holders in the axial direction thereof, means for turning said turret to alternate exchange positions of bobbins held on said bobbin holders between a winding position and a standby position, the improvement wherein said bobbin rotating means comprises a motor, a friction roller driven by said motor for driving said bobbin held on said bobbin holders when the peripheral surface of said bobbin contacts with said friction roller, a power transmission means for transmitting a driving power from said motor to said friction roller, auxiliary means for driving said bobbin for contacting said bobbin with said friction roller and comprising an arm swingably mounted on a shaft of said turret, an auxiliary roller rotatably mounted on said arm, a further motor disposed on a machine frame, and a power transmission means for transmitting driving power of said further motor to said friction roller, and wherein said turret turning means comprises means for turning said turret in a direc-tion opposite to the rotational direction of said bobbins at the time of bobbin exchange, a guide disposed upstream of said yarn traverse means for disengaging said yarn from said yarn traverse means, and a yarn catching groove formed at a peripheral portion of each bobbin.

2. An apparatus as set forth in claim 1 wherein said yarn catching groove formed at a peripheral portion of each bobbin is located in the vicinity of an axial end portion thereof.

3. An apparatus as set forth in claim 2 wherein each bobbin holder is slidable along an axial direction thereof.

4. An apparatus according to claim 1, further comprising a slide block disposed on a machine frame in a slidable condi-tion in an upward or downward direction relative to said bobbin holder, and means for displacing said slide block, said traverse means and said friction roller being carried by said slide block.

5. An apparatus according to claim 4, wherein said dis-placing means is a pneumatic cylinder for supporting said slide block.

6. An apparatus as set forth in claim 4, wherein each bobbin holder is slidable along an axial direction thereof.

7. An apparatus according to claim 1, further comprising means for urging said friction roller toward said bobbin, and means for controlling the urging force created by said urging means.