Apparatus for Handling a Yarn End During a Donning Operation on a Textile Machine

The present invention relates to an apparatus for handling a yarn end during a donning operation on a textile machine and, more particularly, relates to an apparatus for performing the donning operation while continuously delivering yarn produced by a textile machine wherein the yarn is wound on a bobbin mounted on a friction roller.

In the conventional textile machine where the yarn is wound on a bobbin mounted on a friction roller, if the yarn delivering operation is stopped and an auxiliary yarn is wound on a fresh bobbin mounted on the friction roller after doffing a full packaged bobbin from the friction roller, it is necessary to piece an end of the auxiliary yarn with the end of a fresh yarn delivered from a spinning part or delivery part of the textile machine. Consequently, the donning operation becomes very complicated.

To eliminate the above-mentioned complicated operation, several attempts have been made to carry out the donning operation without stopping the spinning or yarn supply operation from the delivery section of the machine to the winding mechanism. In these attempts, the yarn which is continuously delivered from the machine is introduced into a suction means or wound on a waste roller. However, the suction means or waste roller is disposed at a position between the winding mechanism and the delivery part of the textile machine. Consequently, the first winding of the yarn on a fresh bobbin is complicated. This is so because a yarn portion, which is held by holding means such as a suction nozzle, must be introduced into a nip line between the fresh bobbin and the friction roller in a relatively unstretched or slackened condition, after the connection with the holding means.

The principle object of the present invention is to provide an apparatus for performing the donning operation while continuously delivering a yarn from a delivery section of a textile machine, so as to eliminate the abovementioned drawbacks of the conventional donning method and apparatus.

To attain the purpose of the present invention, a portion of yarn taken up from a delivery part of the textile machine is passed beyond a peripheral surface of a friction roller at a point where the friction roller will be contacted by a winding bobbin. The yarn is then held by a holding means. The initial winding of yarn on the fresh bobbin is carried out by displacing an arm which rotatably holds the fresh bobbin in a position where it frictionally contacts the friction roller.

To effectively carry out the donning operation in the present invention, the full packaged bobbin is doffed from the winding mechanism by displacement of the bobbin to a discharge position. The yarn extending between the full bobbin and the delivery section of the textile machine is cut and the cut end of the yarn which is connected to the delivery section of the textile machine, is held by a suction means. Consequently, the so-called yarn retrieving operation can be eliminated.

Further objects and characteristic features of the present invention are clarified by the following detailed illustration of the embodiments with reference to the attached drawings and claims. The latter however, are not limited to the embodiments but are intended to cover modifications within the spirit and scope of the present invention.

FIG. 1 through FIG. 6 are schematic side views of an embodiment according to the present invention, showing steps of a doffing and donning operation;

FIGS. 7 and 8 are schematic plan and side views, respectively, of a part of a cradle utilized for the openend spinning unit according to the present invention;

FIG. 9 is a sectional view of one of cradles taken along a line 9--9 in FIG. 7;

FIG. 10 is an elevational view of the bobbin holding member shown in FIG. 9;

FIG. 11 is a front view of the bobbin holder shown in FIG. 1 through FIG. 6;

FIG. 12 through FIG. 14 are schematic side views of a second embodiment according to the present invention, showing steps of a doffing operation and the initial steps of a donning operation;

FIG. 15 is a schematic side view of the apparatus of the second embodiment wherein the operation for cutting a yarn between a full packaged bobbin displaced from a friction roller and a full yarn package is shown;

FIG. 16 is a schematic side view of the apparatus of the second embodiment, wherein a blowing nozzle utilized for leading a cut-end of the yarn toward a fesh bobbin is shown;

FIG. 17 is a schematic side view of the apparatus of the second embodiment, wherein a modified means for leading a cut-end of the yarn toward a fresh bobbin is shown;

FIG. 18 is a perspective view of a guide plate for defining a yarn passage in the apparatus of the second embodiment;

FIG. 19 is a front elevational view of a cutter utilized for the apparatus of the second embodiment;

FIG. 20 is a front elevational view of a modification of the cutter sohown in FIG. 19;

FIG. 21 is a schematic side view of a modification of the apparatus shown in FIG. 17, wherein a suction nozzle for catching a cut-end of the yarn which is connected to a full packaged bobbin is provided along with an auxiliary cutter;

FIG. 22 is a cross-sectional view of the suction nozzle shown in FIG. 21, taken along a line 22--22 in FIG. 21;

FIG. 23 is a perspective view of a part of the apparatus of the second embodiment, wherein means for forming a transfer tail wind on a fresh bobbin is provided;

FIG. 24 is a perspective view of a third embodiment according to the present invention;

FIG. 25 through FIG. 28 are schematic side views of the third embodiment, showing steps of a doffing operation and a donning operation;

FIG. 29 is a schematic side view of a part of the third embodiment showing the yarn being introduced into the entrance to a slit formed in an arm and then introduced to a terminal of the slit;

FIG. 30 is a schematic front elevational view of the apparatus shown in FIG. 25;

FIG. 31 is a schematic front elevational view of a part of the third embodiment wherein the situation just before cutting the yarn is shown;

FIG. 32 is a sectional view of the apparatus shown in FIG. 31, taken along a line 32--32 in FIG. 31;

FIG. 33 is a schematic front elevational view of a part of the third embodiment wherein the situation just after cutting the yarn is shown;

FIG. 34 is a sectional view of the apparatus shown in FIG. 33, taken along a line 34--34 in FIG. 33.

The apparatus according to the present invention may be utilized on a textile machine such as a yarn winder, a take-up machine in a mill producing filamentary yarn, an open-end spinning machine, etc. However, for the sake of clarity and simplicity in the following detaled illustration of the present invention, only the embodiments related to an open-end spinning machine are illustrated. In the following illustration of three different embodiments, the same elements in each of the embodiments are represented by identical reference numerals, and elements having similar functions in each of the three embodiments are represented by identical reference numerals having the numeral 100, 200 and 300 added thereto in the first, second and third embodiments, respectively.

Referring to FIGS. 1, 2, 3, 4, 5 and 6 wherein the steps of the doffing and donning operations of the first embodiment are shown, a silver 3 contained in a can 2 is supplied to an open-end spinning unit 1. A yarn 11 is delivered from the spinning unit 1 by means of a take-up force created by delivery rollers 4 and 5. The roller 4 is positively driven by a driving mechanism (not shown) while the roller 5 rotatably contacts the roller 4. The yarn 11 is then wound on a bobbin 7 by a take-up mechanism comprising a friction roller 6 and a bobbin holding cradle 113 which is rotatably mounted on a pivot shaft 113a such that the bobbin 7 is capable of contacting the friction roller 6 as shown. In this take-up mechanism, the friction roller 6 is a split drum which is positively driven by a driving mechanism (not shown) and provided with a yarn guide groove for traversing a yarn passage along a longitudinal axis of the bobbin, as shown in FIG. 19. The size of the yarn package formed on the bobbin 7 is increased by rotation of the bobbin 7 until a full yarn package 8 is formed by take-up of the yarn 11. Rotation of bobbin 7 is created by the frictional contact of the yarn package with the split drum 6. Then the full yarn package 8 is doffed from the above-mentioned winding mechanism and displaced to a conveyor belt 12 disposed lengthwise of the open-end spinning machine at a position adjacent to the winding mechanism of the spinning machine.

The bobbin holding cradle 113 mentioned above comprises, as shown in FIGS. 7 and 8, a pair of parallel cradle arms 114 and 115 rotatably mounted on the pivot shaft 113a (FIG. 1) which is rigidly secured to a supporting means (not shown) which in turn is mounted to the frame of each spinning unit. The cradles arms 114, 115 are provided with bobbin catchers 116, 117 whereby a bobbin can be rotatably held. As the construction and function of the bobbin catcher 116 is similar to the bobbin catcher 117, the following illustration only relates to the bobbin catcher 116. Referring to FIGS. 9 and 10, the bobbin catcher 116 comprises a needle bearing 118 which is in splined engagement with a circular hollow space 119 formed in the cradle 114. A bobbin holding member 120 which is rotatably held by the needle bearing 118. The needle bearing 118 is provided with a laterally expanded flange portion 118a which is capable of sliding along the axial direction of the circular hollow space 119 at the laterally expanded portin 119a. A cover member 121 is rigidly mounted to the cradle 114 by set screws 122 such that the bearing 118 assembled with the bobbin holding member 120 is capable of being displaced into a space between the cradle 114 and an inside wall of the cover member 121. A ring shaped cover member 123 is rigidly mounted to the cradle 114 by set screws 124 such that the head portion 120a of the bobbin holding member 120 is capable of being displaced within an aperture formed in the ring 123. An expansion helical spring 125 is mounted on the needle bearing 118 in a cylindrical space 126 formed between the cylindrical surface 119a and the peripheral surface of the needle bearing 118 so that the needle bearing is always urged toward the head portion 120a along the axial direction of the bobbin holding member 120 and the head portion 120a is always urged outwardly from the outside surface of the ring shaped cover 123. The head portion 120a of the bobbin holding member 120 is provided with a partial spherical surface which is capable of being inserted into a cylindrical hollow formed in a fresh bobbin 7a. Consequently, if a fresh bobbin 7a is pushed into the intervening space between the head portions of the bobbin holding members of the bobbin catchers 116, 117, the above-mentioned head portions are first displaced toward the covers of the bobbin catchers 116 and 117 and then these head portions are inserted into the cylindrical space at the two end portions of the bobbin 7a. Consequently, the two ends of the fresh bobbin are rotatably caught and held by these bobbin catchers 116, 117.

In this embodiment, the cradle 113 is capable of turning upward from the split drum 6. A suction duct 110 is disposed above each take-up mechanism. A suction nozzle 109 is connected to the suction duct 110 is disposed above the cradle 113 directly above each take-up mechanism. Consequently, after doffing a full yarn package 8 from the bobbin catchers 116, 117, when the yarn 11 carried from the delivery rollers 4 and 5 is sucked into the suction nozzle 109, the yarn passes beyond the surface of the split drum 6 on the side where the yarn package normally contacts the split drum 6. A bobbin holder 128 is mounted to the bottom outside of the suction nozzle 109 so as to detachably hold the fresh bobbin 7a in such a condition, that, when the bobbin holding cradle 113 is turned toward the suction nozzle 109, the bobbin holding means comprising the bobbin catchers 116 and 117 arrives at the position of the bobbin holder 128. The fresh bobbin 7a is then automatically transferred from the bobbin holder 128 to the bobbin holding means of the cradle 113 simple by moving the cradle to position shown in FIG. 3.

To clarify the above-mentioned bobbin transfer motion, the construction of the bobbin holder 128 is illustrated in more detail. Referring to FIG. 11, the bobbin holder 128 comprises a curved spring plate composed of an upside-down U-shaped top portion 128a which is secured to the suction tube 109 (FIG. 1), a pair of round portions 128b, 128c extended downward from legs of the reverse U-shaped top portion 128a and a pair of channel portions 128d, 128e extended downward from the round portions 128b, 128c, respectively. The space between round portions 128b, 128c coincides with a portion of the cylindrical outer surface of a fresh bobbin 7a while the intervened space between the channel portions 128d and 128e is so narrow that a fresh bobbin 7a held by the round portions 128b, 128c cannot freely fall down therethrough. However, if the fresh bobbin 7a held by the round portions 128b, 128c of the bobbin holder 128 is also held at its two axial ends by the holding means of the cradle 113 and pushed downward by displacing the holding means of the cradle 113 downward, the channel portions 128d, 128e are forced to expand so as to permit the escape of the fresh bobbin 7a from the holder 128. It is essential to dispose the bobbin holder 128 at a position where the fresh bobbin 7a, held by the bobbin holder 128, is capable of being caught at its two axial ends by the bobbin holding means of the cradle 113 when the cradle 113 is turned toward the suction nozzle 109. Consequently, when the cradle 113 is turned toward the suction nozzle 109 and the holding means of the cradle 113 comes to the position in the bobbin holder 128, each holding member of bobbin catchers 116 and 117 is firstly pushed into the aperture of the respective cradle 114 (115) when the fresh bobbin 7a contacts the head portion 120a of each bobbin holding member 120, and then the head portions 120a engage the axial hollow ends of the fresh bobbin 7a. In other words, the fresh bobbin 7a is held by the catchers of the cradle 113, after this fresh bobbin 7a is taken from the bobbin holder 128 by the turning of the cradle 113 toward the split drum 6. In this embodiment, it is further essential to dispose the bobbin holder 128 at a position on the suction nozzle 109 opposite and above both the path of yarn passage over the split drum 6 and the conveyor 12 (FIGS. 1 and 2). A guide plate 129 is disposed between the split drum 6 and the conveyer 12 so as to guide a full yarn package 8 to the conveyer 12.

Next, the donning operation according to the first embodiment is hereinafter illustrated in detail. In this embodiment, a fresh bobbin 7a is inserted into each bobbin holder 128 of each spinning unit before commencing the doffing operation as shown in FIG. 1.

When a full yarn package 8 has been formed on a bobbin 7, the doffing operation is commenced. An operator cuts the yarn 11 at a position between the delivery rollers 4, 5 and the take-up roller 6. The above-mentioned cutting operation is carried out manually or by using a suitable cutting apparatus. The yarn portion connected to the yarn package 8 is wound around the yarn package 8 and, if the above-mentioned operation is carried out manually, the end of the yarn connected to the yarn delivered from the delivery rollers 4 and 5 is held in the hand of the operator. Then after doffing the full yarn package 8 from the cradle 113, the cradle 113 is turned toward the suction nozzle 109 manually. (see arrow in FIG. 2)

During the above-mentioned upward turning motion of the cradle 113, the full yarn package 8 rolls along a slope formed on the guide plate 129 toward the conveyor belt 12 and rests on the conveyor belt 12. The yarn 11 is continuously being delivered from the delivery rollers 4 and 5 and is carried to the suction nozzle 109 so as to be continuously sucked thereinto. (FIG. 3)

When the cradle 113 is turned to a terminal position of its upward turning motion, the bobbin catchers 116, 117 of the cradle 113 holds a fresh bobbin 7a, which is also being held by the bobbin holder 128 as already illustrated, while the yarn 11a continuously being delivered from the delivery rollers 4 and 5 is continuously sucked into the suction nozzle 109.

In the above-mentioned condition, the conveyor belt 12 carries the full yarn package 8 outside the open-end spinning machine. After that the yarn 11a is introduced onto the split drum 6 by the downward turning motion of the fresh bobbin 7a, which is rotatably held by the bobbin catchers 116, 117 of the cradle 113, and nipped by the fresh bobbin 7a and the split drum 6. (FIG. 4)

Next, the yarn 11a between the suction nozzle 109 and the fresh bobbin 7a is cut manually or by a suitable cutting device (not shown) into two portions 11c and 11d. The portion 11d extends from the suction nozzle 109, while the portion 11c extends from the fresh bobbin 7a. The yarn portion 11d is sucked into the suction nozzle 109, while the portion 11c of the yarn 11a falls on the fresh bobbin 7a so that the yarn portion 11d is wound on the bobbin 7a due to the rotation of the bobbin 7a (FIG. 5).

The winding of yarn portion 11d on the bobbin 7a sets the yarn on the bobbin for the commencement of the bobbin winding operation (FIG. 6).

In the above-mentioned embodiment, the suction of the suction duct 110 may be actuated only at the time of carrying out the above-mentioned doffing and donning operation. Further, the conveyor belt 12 may be omitted, in which case a reserve box or carrier for temporarily storing the full yarn packages may be utilized. If the above-mentioned bobbin holder 128 is omitted from the open-end spinning machine, a fresh bobbin 7a is mounted on the cradle 113 while the cut-end of the yarn 11a is continuously sucked into the suction nozzle 109, so that the fresh bobbin 7a pushes the yarn 11a toward the split drum 6.

Next, the construction and function of the second embodiment is hereinafter illustrated in detail. In this embodiment, when a full yarn package is displaced from the take-up mechanism to the conveyer belt, the operation of cutting yarn between the take-up mechanism and the conveyer is automatically carried out. The yarn which is continuously delivered from the delivery rollers of the spinning unit is continuously held in a condition such that the continuously delivered yarn passes along the position of the periphery of the round surface of the split drum which is contacted by a fresh bobbin or yarn package during the take-up operation.

Referring to FIGS. 12, 13 and 14, a cradle 213 has a construction similar to the cradle 113 shown in the first embodiment. At a position above the cradle 213 a bobbin holder 228, which has a construction similar to the bobbin holder 128, is disposed. The relative position of the bobbin holder 228 to the bobbin catcher (not shown) of the cradle 213 is similar to the first embodiment. Therefore, when the cradle 213 is turned upward about a shaft 213a, and the cradle 213 comes to the terminal position of its upward turning motion, a fresh bobbin 7a held by the bobbin holder 228 is also caught by the bobbin catcher (not shown) of the cradle 213. Then when the cradle 213 is turned downward toward the split drum 6, the bobbin 7a is released from the bobbin holder 228 and held only by the above-mentioned bobbin catcher. A modified guide plate 215 is disposed between the take-up mechanism and the conveyor belt 12. As shown in FIG. 18, the guide plate 215 is provided with a slit 216 and a suction nozzle 209 (FIGS. 12, 13 and 14) is disposed right below the slit 216. The suction nozzle 209 is connected to a suction duct 210. A pair of cutting devices 217 and 218 are disposed at the positions outside of the suction nozzle 209 shown in the drawings. That is, the cutting device 217 is disposed between the suction nozzle 209 and the conveyor belt 12, so that a yarn 11 connected to a full yarn package 8 carried to the conveyer belt 12 is cut, while the cutting device 218 is disposed between the suction nozzle 209 and the split drum 6, so that a yarn 11 from the split drum 6 is cut. To carry out the above-mentioned cutting operation without failure, it is necessary to introduce the yarn 11 into the slit 216. To attain the above-mentioned condition, the shape of the guide plate 215 and the disposition of the slit 216 are of particular importance. That is, a plate having a reverse U-shaped lateral cross section is utilized for the guide plate 215 and the slit 216 formed on the flat portion 215a extends to one of the leg portions 215b. Consequently, when the yarn is introduced into the slit 216, the yarn passes along a straight passage between the two terminals of slit 216, which passage lies under the flat portion 215a. Further, the suction force of the suction nozzle 209 is preferably applied to the slit 216 to aid in moving the yarn 11 to the slit 216 through either by the traverse motion of the split drum 6, or the motion of the conveyer belt 12 which displaces the full yarn package along the longitudinal direction of the guide plate 215. As shown in FIG. 18, the slit 216 may be modified to take the shape of the slit denoted by numerals 216a.

The detailed construction of the above-mentioned cutting devices 217 and 218 are shown in FIGS. 19 and 20. The cuttng knives 222 of the cutting device 217 are mounted on a horizontal bar 221 that each cutting knife 222 is disposed adjacent to each spinning unit. These cutting knives 222 may be mounted as a single body or separately on the bar 221. The bar 221 is supported by a pair of arms 225, 226 which are pivotably mounted on pivot shafts 224a, 224b. Arms 225, 226 are mounted on brackets 223a, 223b, the arm 225 being connected to a crank shaft 233 via levers 230 and 232 so that the arm 225 is capable of reciprocally swinging between the positions represented by a solid line and a broken line. In the above-mentioned embodiment, reference numerals 227, 229, 231 are connecting pins while the reference numeral 228 represents an extended portion of the arm 225. The above-mentioned reciprocal pivoting motion is created by the crank motion of the lever 232. This reciprocal pivoting motion, together with the up and down motion of the cutting device 217, moves the yarn 11 along and in contact with the knife edge and toward the knife. Consequently, the cutting operation of the yarn 11 can be carried out without failure. Referring to FIG. 20, the cutting device 218 comprises a stationary cutting knife 238 and a movable cutting knife 237 whereby a scissors type cutter is formed. The movable knife 237 is actuated by a solenoid 400. That is, the knife 237 is rotatably mounted on a pivot shaft 236, and the bottom end portion of the knife 237 is connected to a plunger 234 of the solenoid 400. A helical spring 235 is mounted on the plunger 234 so as to assist the return motion of the plunger 234.

In the above-mentioned embodiment, either one of the cutting devices 217 and 218 may be actuated before the other, or both of cutting devices 217 and 218 may be actuated simultaneously. The cutting operation is carried out after the fresh bobbin 7a held by the cradle 218 contacts the split drum 6. It is of course required that the yarn portion 11c extending from the split drum 6 be wound upon the fresh bobbin 7a. When shown in FIG. 15, as the cutting device 218 is actuated the yarn 11 between the split drum 6 and the suction nozzle 209 is tensioned. Thus, the yarn portion 11c tends to jump towards the fresh bobbin 7a. However, to assure that the cut yarn portion 11c comes into contact with the fresh bobbin 7a, it is preferable to utilize an auxiliary blowing nozzle 220. Blowing nozzle 220 is connected to a blowing duct 219 as shown in FIG. 16. In FIG. 16, the blowing nozzle 220 which is connected to the blowing duct 219 is disposed between the split drum 6 and the cutting device 218 at a position just below the slit 216. Consequently, if the blowing nozzle 220 is actuated simultaneously with the actuation of the cutting device 218, the yarn end portion 11c is urged toward the fresh bobbin 7a by the blowing force created by the nozzle 220 and by its natural tendency to jump toward the fresh bobbin 7a. When the yarn end portion 11c comes into contact with the fresh bobbin 7a, which is turning in the direction indicated by arrow D, the yarn end portion 11c can be easily picked up by the fresh bobbin 7a.

A mechanical means for introducing the yarn end portion 11c to the split drum 6 is shown in FIGS. 17, 21 and 23. Referring to FIG. 17, a rod 246 provided with a yarn receiver 247 is connected to a push rod 241 via a swing plate 243. The swing plate 243 is swingably mounted on a bracket (not shown) by a pivot shaft 244. The lower end of the rod 246 is connected to the swing plate 243 by a connecting pin 245, while the push rod 241 is slidably mounted in a guide aperture in bracket 240. Bracket 240 is in turn secured to a machine frame (not shown) and connected to the swing plate 243 by a connecting pin 242. The rod 246 is capable of being displaced upward by pushing the rod 241 from a first holding position represented by a broken line to a position represented by a solid line in FIG. 17, while the rod 246 and the swing plate 243 are capable of being displaced downward by their own weight. The yarn receiving portion 247 of the rod 246 is normally positioned at the first position where it is held below the yarn passage between the split drum 6 and the suction nozzle 209 without its contracting the yarn during the normal take-up operation. However, when the push rod 241 is pushed, the rod 246 is displaced upward so that the yarn receiving portion 247 contacts the yarn portion 11c and urges it upwardly. Consequently, the yarn portion 11c can be more easily picked up by the fresh bobbin 7a. In the above-mentioned embodiment, it is preferable to provide a friction surface such as a brush surface, etc., on the yarn receiving portion 247 of the rod 246. This is because, if the yarn portion 11c is caught by the brush on the yarn receiving portion 247 while the end of yarn portion 11c is being sucked into the suction nozzle 209, the displacement of yarn portion 11c into the suction nozzle 209 is prevented, in addition the yarn portion 11a continuously supplied from the delivery rollers 4 and 5 is relieved of tension between the point where the split drum 6 contacts the fresh bobbin 7a and the yarn receiving portion 247 of the rod 246. As a result the slackened portion of the yarn 11a can be easily wound on the fresh bobbin 7a. After this initial winding operation, the cutting device 218 is actuated to cut the yarn portion 11c between the receiving portion 247 of the rod 246 and the suction nozzle 209, so that the cut-end portion of the yarn portion 11c is taken up by the fresh bobbin 6.

In the modified embodiment shown in FIG. 23, the yarn receiving portion 247 is provided with a yarn collecting guide portion 247a whereby a transfer tail wind 11i can be easily formed at the end portion of the fresh bobbin 7a. In this embodiment, the positions of the slit 216, suction nozzle 209 and the cutting device 218 are in line with the position of the yarn collecting guide portion 247a. However, the functions of these elements are quite similar to the embodiment shown in FIG. 17, except that the time of actuation of the cutting device 218 is just after the forming of the above-mentioned transfer tail wind 11i on the fresh bobbin 7a.

In the modified embodiment shown in FIG. 21, the cutting device 218 of the previous embodiment is omitted, and the suction nozzle 209 is given the function of severing the yarn portion 11c. The suction nozzle 209 is provided with an aperture 248 formed below the top of the nozzle. The aperture 248 opens into suction nozzle 209 along a tangential direction to the inside cylindrical wall of nozzle 209 as shown in FIG. 22.

Therefore, a rotating air current is created in the nozzle which rotates about the longitudinal axis of the suction nozzle 209. According to the above-mentioned rotating air current, the yarn portion 11c is turned toward its untwisting state so that individual fibers of the yarn portion 11c are liberated and sucked into the nozzle 209. Consequently, in spite of continuously introducing the yarn portion 11c into the suction nozzle 209, the length of yarn portion 11c in the nozzle 209 is maintained substantially constant. Under the above-mentioned condition, when the rod 246 is shifted upward so as to carry the yarn portion 11c upward by means of the yarn receiving portion 247, the end of the yarn portion 11c is pulled out of the suction nozzle 209. Therefore, the yarn portion 11c can be easily wound on the fresh bobbin 7a. If air is positively supplied into the suction nozzle 209 via the aperture 248, the above-mentioned untwisting of the yarn is carried out more effectively.

Next, the doffing operation by the above-mentioned second embodiment is illustrated with reference to the basic second embodiment shown in FIG. 12 through FIG. 14.

As in the case of the first embodiment, a fresh bobbin 7a is inserted into the bobbin holder 228. Upon forming a full yarn package 8, the doffing operation is commenced. (FIG. 12)

The operator turns the cradle 213 upward and takes off the full yarn package 8 from the cradle 213 so that the full yarn package 8 rolls along the guide plate 215 and is received by the conveyor belt 12. According to the above-mentioned doffing motion, the yarn 11 passes through the slit 216 (not shown) and is sucked into the suction nozzle 209. The cradle 213 is turned to its uppermost position and the fresh bobbin 7a which is being held by the bobbin holder 228 is grasped by the bobbin catcher (not shown) of the cradle 213 in a manner similar to the first embodiment. (FIG. 13)

When the cradle 213 is turned toward the split drum 6, the fresh bobbin 7a is released from the bobbin holder 228 and held only by the bobbin catcher of the cradle 213. Upon contact of the fresh bobbin 7a with the split drum 6, as the cutting devices 217 and 218 are actuated, the cut piece of yarn 11d (FIG. 14) in the suction nozzle 209 is sucked into the suction duct 210, while the yarn portion 11c is wound on the fresh bobbin 7a so that the winding operation on the fresh bobbin 7a is commenced. (FIG. 14)

In the above-mentioned two embodiments, the suction nozzle is utilized for forming a yarn passage at a position in front of a part of the peripheral surface of the friction roller 6 by which the yarn 11 passes during the normal taking-up operation. However, a conventional waste roller may be utilized instead of the suction nozzle.

In the third embodiment shown in FIGS. 24, 25, 26, 27, 28, 29 and 30, the cradle 313 is capable of holding an end of the yarn delivered from the delivery rollers and cutting the yarn connected to a full yarn package which has been doffed from the take-up mechanism. The end of yarn delivered from the delivery rollers is then automatically wound on a fresh bobbin 7a which is rotatably mounted on the cradle.

Referring to FIG. 24, the cradle 313 comprises a pair of cradle arms 313a, 313b. The cradle arm 313a does not have a handle as does arm 313b and is provided with a suction nozzle 309 which holds the yarn. The suction nozzle 309 is provided with a slit 309a which extends from a front free end thereof toward a position beyond and adjacent the bobbin carrier (not shown) of the cradle 313a. The nozzle 309 sucks the yarn portion 11a delivered from the delivery rollers 4 and 5 during the doffing and donning operation. The slit 309a carries the cut-end portion of the yarn 11a which is connected to the yarn being delivered from the delivery rollers 4 and 5 to a position where the yarn 11a is wound on the fresh bobbin 7a. The slit 309a is provided with a particular shape to achieve this. Specifically an upstream terminal 309b of the slit 309a is located at the bottom portion of the aperture of the nozzle 309 so as to prevent the introduction of the yarn 11a into the slit 309a at the beginning of the operation. After doffing a full yarn package 8 and the holding of a fresh bobbin 7a in the cradle 313, the operator introduces the yarn 11a into the slit 309a manually and carries the yarn 11a from the upstream terminal 309b to a downstream terminal 309c of the slit 309a. As shown in FIGS. 29 and 30, if the yarn 11a is carried to the downstream terminal 309c while the full yarn package 8 is being held by the cradle arms 313a, 313b, the yarn 11a is automatically introduced into the contact line between the split drum 6 and the full yarn package 8. Consequently, the yarn 11a is introduced into a transverse groove of the split drum 6 so that the yarn 11a is wound on the full yarn package 8. To prevent this it is necessary to select the time at which the yarn 11a is introduced into the downstream terminal 309 c of the slit 309a to be the time when winding on a fresh bobbin 7a is commenced.

The detailed construction and function of the third embodiment according to the present invention is hereinafter explained in detail. The bobbin catchers 350a, 350b are mounted on the cradle arms 313a, 313b, respectively. These bobbin catchers 350a, 350b have a construction similar to the first embodiment. A yarn catching pin 351 is rigidly mounted on the bobbin catcher 350a at a position on the outside peripheral surface as shown in FIGS. 31, 32. A cutter 317 is mounted on the cradle arm 313a and provided with a sharp knife edge on its bottom and a pair of guide pieces 352a and 352b adjacent the two outside positions of the cutter 317. The relative arrangement of these elements (the slit terminal 309c, cutter 317 and the pin 351) are shown in FIGS. 31, 32, 33 and 34. When the cradle arm 313a is turned upward, the yarn 11a does not contact the knife edge of the cutter 317. However, when the cradle arm 313a is turned downward and a fresh bobbin 7a comes into contact with the split drum 6, the yarn 11a introduced into the slit terminal 309c is introduced into a space between the guide pieces 352a and 352b and is caught by the pin 351. Consequently, the yarn 11a is urged against the knife edge of the cutter 317 so that the yarn 11a is severed. The cut end 11c of the yarn 11a on the split drum 6 side is wound on the fresh bobbin 7a while being held by the pin 351. The cut ends 11d of the yarn 11a on the slit 309a side is sucked into the nozzle 309. A bobbin holder 328 (FIG. 28) is mounted on a bracket (not shown) secured to a frame of a spinning unit, the construction and function of the bobbin holder 328 being quite similar to the first and second embodiments. Therefore, when the cradle arms 313a, 313b are turned upward to their terminal position, a fresh bobbin 7a, which is being held by the bobbin holder 328, is also grasped by the bobbin catchers 350a, 350b. When the cradle arms 313a, 313b commence to turn downward, the fresh bobbin 7a is released from the bobbin holder 328 and held only by the cradle arms 313a, 313b. In this embodiment, a guide plate 315 is mounted as in the first and second embodiments so as to guide the full yarn package 8 toward the conveyor belt 12. A suction duct 310 (FIG. 25) is connected to the suction nozzle 309 by way of a flexible hose. The suction duct 310 may be actuated just before the doffing and donning operation.

Next, the doffing and donning operation of the third embodiment is hereinafter explained.

Before a full yarn package 8 is formed, a fresh bobbin 7a is inserted into the bobbin holder 328. And when a full yarn package 8 is formed, the doffing operation is commenced. (FIG. 25)

The operator cuts the yarn 11 at a position between the delivery rollers 4 and 5 and the split drum 6. The above-mentioned cutting operation is carried out manually or by utilizing a suitable cutting device. The yarn portion 11a which is continuously being delivered from the delivery rollers 4 and 5 is held by hand while the yarn portion 11b on the split drum side is wound on the full yarn package 8. (FIG. 26)

The yarn portion 11a held by hand is introduced into the suction nozzle 309 and the cradle arms are turned upward. During the above-mentioned upward turning motion of the cradles, the full yarn package 8 is manually pushed out from the bobbin catchers 350a, 350b so that the full yarn package 8 rolls along the guide plate 315 to the conveyer belt 12. Upon arrival of the cradle arms 313a, 313b at the terminal of their upward motion, the fresh bobbin 7a held by the bobbin holder 328 is automatically grasped by the bobbin catchers 350a, 350b. Thereafter, the yarn portion 11a is introduced to the slit terminal 309c. In the above-mentioned condition, the yarn portion 11a passes beyond the part of peripheral surface of the split drum 6 which is contacted by bobbin 7a or a yarn package during the normal taking up operation. (FIG. 27)

When the operator turns the cradle arms 313a, 313b downward toward the split drum 6, the yarn portion 11a is pushed by the fresh bobbin 7a toward the split drum 6, and simultaneously the yarn portion 11a is cut by the cutter 317. The yarn which is delivered from the delivery rollers 4 and 5 is wound on the fresh bobbin 7a which is rotating by the frictional contact with the split drum 6 as described hereinbefore. The full yarn package 8 received by the conveyor belt 12 is carried outside the open-end spinning machine. (FIG. 28)