US3921923A

US3921923A - Yarn transfer method in an automatic take-up motion

Info

Publication number: US3921923A
Application number: US530487A
Authority: US
Inventors: Masanori Kuno; Tadaaki Kato
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1973-12-24
Filing date: 1974-12-06
Publication date: 1975-11-25
Anticipated expiration: 1992-11-25
Also published as: FR2255243B1; JPS5090734A; DE2459990A1; FR2255243A1; CH577931A5; IT1027995B; JPS5417860B2; DE2459990B2

Abstract

In an automatic take-up motion of peripheral drive turret type, a method of automatically transferring a yarn from a first bobbin on which said yarn has been being taken-up to a second unwound bobbin on which said yarn is to be wound subsequently, is disclosed herein. These first and second bobbins are mounted on a turret mechanism so as to be readily exchanged in position by rotating said turret mechanism. This novel yarn transfer method consists of the steps of driving said first and second bobbins with independent electric motors, lowering a traverse speed of the yarn to a speed that is most suitable for formation of a transfer tail, displacing a traverse cam roll with a pneumatic cylinder or other known means so as to make the yarn contact with a yarn grasping device provided at an end of the bobbins or on a bobbin holder and to make the yarn grasping device grasp said yarn, cutting off the yarn between said yarn grasping device and the fully wound first take-up bobbin by means of a cutter associated with said yarn grasping device to take-up the yarn on the second unwound bobbin, restoring the traverse cam roll to its normal position simultaneously with the formation of the transfer tail, accelerating the traverse speed up to a speed upon normal take-up operation, pressing the unwound second bobbin against a driving roll, switching off a power supply to said independent electric motors for driving the bobbins, and then carrying out the take-up operation with a peripheral drive system.

Description

United States Patent [191 Kuno et al.

[ Nov. 25, 1975 I YARN TRANSFER METHOD IN AN AUTOMATIC TAKE-UP MOTION [75] Inventors: Masanori Kuno, Chiryu; Tadaaki Kato, Nagoya, both of Japan [73] Assignee: Mitsubishi Jukogyo Kabushiki Kaisha, Tokyo, Japan [22] Filed: Dec. 6, 1974 [21] Appl. No.: 530,487

[30] Foreign Application Priority Data Dec. 24, 1973 Japan 48-2432 [52] US. Cl. 242/18 A; 242/18 PW [51] Int. Cl. B65H 67/04 [58] Field of Search 242/18 A, 18 PW, 18 DD, 242/18 G, 25 A [56] References Cited Primary Examiner-Stanley N. Gilreath Attorney, Agent, or FirmCushman, Darby & Cushman [57] 4 ABSTRACT In an automatic take-up motion of peripheral drive turret type, a method of automatically transferring a yarn from a first bobbin on which said yarn has been being taken-up to a second unwound bobbin on which said yarn is to be wound subsequently, is disclosed herein. These first and second bobbins are mounted on a turret mechanism so as to be readily exchanged in position by rotating said turret mechanism. This novel yarn transfer method consists of the steps of driving said first and second bobbins with independent electric motors, lowering a traverse speed of the yarn to a speed that is most suitable for formation of a transfer tail, displacing a traverse cam roll with a pneumatic cylinder or other known means so as to make the yarn contact with a yarn grasping device provided at an end of the bobbins or on a bobbin holder and to make the yarn grasping device grasp said yarn, cutting off the yarn between said yarn grasping device and the fully wound first take-up bobbin by means of a cutter associated with said yarn grasping device to take-up the yarn on the second unwound bobbin, restoring the traverse cam roll to its normal position simultaneously with the formation of the transfer tail, accelerating the traverse speed up to a speed upon normal take-up operation, pressing the unwound second bobbin against a driving roll, switching off a power supply to said independent electric motors for driving the bobbins, and then carrying out the take-up operation with a peripheral drive system.

1 Claim, 5 Drawing Figures US. Patent Nov. 25, 1975 Sheetlof3 3,921,923

US. Patent Nov. 25, 1975 Sheet20f3 3,921,923

US. Patent Nov. 25, 1975 Sheet3of3 3,921,923

YARN TRANSFER METHOD IN AN AUTOMATIC TAKE-UP MOTION CATEGORY OF THE INVENTION This invention relates in general to improvements in an automatic take-up motion, and more particularly to improvement in a method of automatically transferring a yarn from a first bobbin on which said yarn has been being taken-upto a second unwound bobbin on which said yarn is to be wound subsequently in said automatic take-up motion.

BACKGROUND OF THE INVENTION Heretofore, the so-called automatic take-up motions in which a yarn being taken-up on a fully wound bobbin is transferred onto an unwound bobbin without interrupting the take-up operation and thereby the yarn can be taken-up continuously, have been proposed. However, these automatic take-up motions in the prior art all had difficulties in the method of transferring a yarn being taken-up to a unwound bobbin, and no satisfactory one could be obtained in respect to reliability in yarn transfer as well as formation of a transfer tail. More particularly, although the formation of the transfer tail was possible according to the method of transferring a yarn in which after the yarn has been taken-up on a fully wound bobbin the yarn is disengaged from a traverse guide and then the yarn is engaged to a yarn grasping device provided at an end of an unwound bobbin or on a bobbin holder, there was a fear that a yarn may be taken-up on the fully wound bobbin without being traversed and thus a fully wound package may possibly get out of shape upon high speed taken-up operation, because the yarn was disengaged from the traverse guide. On the other hand, according to the method of transferring a yarn in which a yarn is kept inserted in a traverse guide and while traversing the yarn it is engaged to a yarn grasping device provided on an unwound bobbin, the transfer operation of the yarn could be achieved satisfactorily to a certain extent, but it was impossible to form a transfer tail because the yarn was always traversed.

SUMMARY OF THE INVENTION The present invention has been worked out in order to obviate the aforementioned disadvantages in the prior art, and it is a principal object of the present invention to provide a novel yarn transfer method in an automatic take-up motion, in which a transfer tail can be formed and also transfer of a yarn can be achieved reliably by continuing traverse of the yarn without disengaging the yam from a traverse guide and by carrying out transfer of the yarn while it is being taken-up on a fully wound bobbin.

According to one feature of the present invention, a method of transferring a yarn in an automatic take-up motion consists of the steps of driving bobbins with independent electric motors, lowering a traverse speed to a speed that is most suitable for formation of a transfer tail, displacing a traverse cam roll with a pneumatic cylinder or other known means so as to make the yarn contact with a yarn grasping device provided at an end of the bobbins or on a bobbin holder and to make the yarn grasping device grasp said yarn, cutting off the yarn between said yarn grasping device and a fully wound take-up bobbin by means of a cutter associated with said yarn grasping device to take up the yarn newly on an unwound bobbin, restoring the traverse cam roll to its normal positionsimultaneously with the formation of the transfer tail, accelerating the traverse speed up to a speed upon normal take-up operation, pressing the unwound bobbins against a driving roll, switching off a power supply to said independent electric motors for driving the bobbins, and then carrying out the take-up operation with a peripheral drive system.

Above-mentioned and other features and objects of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a cross-sectional side view of an automatic take-up motion which practices the method according to the present invention,

FIGS. 2, 3 and 4 are diagrammatic views showing successive states in a take-up operation of a part of the apparatus in FIG. 1, and

FIG. 5 is a timing chart showing the time sequence of the actuation of the respective component parts in the same apparatus upon automatically transferring a yarn from one bobbin to'another.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT:

Referring now to the drawings, especially to FIG. 1, reference numeral 1 designates a drive roll, numeral 2 designates a traverse cam roll, numeral 3 a traverse guide, and numerals 4, 4' bearings for supporting the traverse cam roll 2, said bearings 4, 4' being slidably held within a cam box (5). Numeral 6 designates a pneumatic cylinder (having a stroke of about mm) for displacing the traverse cam roll 2 and is coupled to the bearing 4. Numeral 7 designates an electric motor for driving the traverse cam roll 2, which is telescopically coupled to the traverse cam roll 2 through a coupling mechanism 8. Numeral 9 designates another electric motor for the drive roll 1. It is to be noted that the aforementioned drive roll 1 is adapted to be pressed against a bobbin by any appropriate butting means (not shown).

Reference numerals

10, 10 designate bobbin,

holders held by a turret arm 11.

Numerals

12, 12 designate electric motors for accelerating the bobbins, which are contained within the bobbin holders l0 and 10, respectively, and which are connected to an external power supply (not shown) through wires 13 and slip rings 14. Numeral 15 designates an unwound bobbin, numeral 15 designates a fully wound bobbin, and numerals l6 and 16' designate yarn grasping devices provided on the respective bobbins l5 and 15. Numeral l7 designates yarns at the opposite traverse end positions during the period when the yarn is traversed in a normal take-up operation, numeral 18 designates yarns at the opposite traverse end positions during the period when the traverse cam roll 2 has been displaced by actuating the pneumatic cylinder 6 so that the yarn may contact with the yarn grasping device 16, numeral 19 v 15 has become fully wound, the electric motor 12 contained within the bobbin holder for the unwound.

bobbin is automatically switched on to accelerate the unwound bobbin 15 until it acquires such r.p.m. that its peripheral velocity becomes equal to or higher than the linear velocity of the yarn that is being wound on the fully woundbobbin 15' (FIG. 2). Subsequently, after the rpm. of the unwound bobbin has been completely raised, the turret arm 11 is rotated to separate the fully wound bobbin 15 from the drive roll 1 and to bring the unwound bobbin 15 to a position just in front of the position where it contacts with the drive roll 1 (FIG. 3). Substantially in coincidence with the separation of the fully wound bobbin 15' from the drive roll 1, the traverse speed control device 19 is actuated to lower the traverse speed to a speed most suitable for formation of a transfer tail (30 100 rpm). Since the fully wound bobbin 15 becomes not to be applied with a driving force as it leaves the drive roll 1 at this moment, in order to prevent the yarn from slackening the electric motor 12 contained within the bobbin holder 10 for the fully wound bobbin 15 is switched on simultaneously with the rotation of the turret arm 11 and thereby a tension in the yarn can be maintained. Then the yarn is taken-up on the fully wound bobbin l5" and traversed at a reduced traverse speed, while it is slipping on the surface of the unwound bobbin 15 that is being rotated at a high speed. Simultaneously with the rotation of the turretarm 1 l, the pneumatic cylinder 6 is actuated to displace the traverse cam roll 2 by about mm so that the traverse motion may be performed up to the position where the yarn makes contact withthe yarn grasping device 16 provided at one end of the bobbin. In this way, the yarn l8 traversed up to the position above the yarn grasping device 16 is at once en-. gaged with the yarn grasping device 16 that is rotating with a relative velocity to the yarn, and a new take-up operation on the unwound bobbin 15 is commenced as the yarn is traversed at a reduced speed from that end of the unwound bobbin 15 towards its central portion. On the other hand, the yarn which has been being taken up on the fully wound bobbin 15' is cut off by means of a cutter associated with the yarn grasping device. Then the commencement of the take-up operation is detected by means of the photoelectric tube means 20, and in response to the detected signal, the pneumatic cylinder 6 is again actuated to restore the traverse cam roll 2 to its normal position, the traverse speed control device 19 is actuated to realize a normal traverse speed, the unwound bobbin 15 is pressed against the drive roll 1, and simultaneously therewith the

electric motors

12 and 12 contained within the

respective bobbin holders

10 and 10 are switched off. The unwound bobbin 15 is frictionally driven by the drive roll I to achieve the conventional surface drive type of take-up operation. The above-referred respective operations are continuously and automatically carried out during several seconds, and thus the transfer of the yarn has been finished.

Now the present invention will be further explained in more detail in connection to the following practical example:

EXAMPLE Yarn Speed: 2500m/min. Number of Ends: 1 end/bobbin holder Number of Bobbins: l bobbin/bobbin holder Bobbin Size: Outer Diameter 89mm X lnner Diameter 73mm d) X Length 340mm Traverse Length: 305mm Traverse Frequency: 700 times/min. upon normal takeup operation 60 times/min. upon yarn transfer-opera tion Stroke of Displacement for Traverse Means: 20mm Maximum Wound Diameter: 250mm Yarn: nylon stretched yarn of 420 denier Outer Diameter of Drive Roll: mm 4) Yarn Grasping Device: a ring having a saw-tooth shaped cutter Electric Power Supply for Electric Motors for Drive Roll and Those Contained within Bobbin Holders: 21 common power supply (The power supply for driving the fully wound bobbin uses an auto-transformer of slide type to regulate the voltage.)

Traverse Speed Control Device: A speed control sys U tem is employed, in which inverter power supplies for high speed operation and for low speed operation are I individually provided and upon yarn transfer-these, power supplies are switched from one to another to achieve speed control.

With regard to the above-referred example, the time sequence of the actuation of the respective components parts can be illustrated as shown in FIG. 5. I

As described above, according to the present invention, under the condition that an unwound bobbin asso-, w ciated with an acceleratingelectric motor is rotating at:

a peripheral velocity that is most suitable for making a yarn wind itself round the bobbin as accelerated by said accelerating electric motor, the unwound bobbin is made to contact with the yarn that is being taken-up on a fully wound bobbin, then the yarn travelling towards the fully wound bobbin is transferred to the unwound bobbin by actuation of a yarn grasping device at an end vice provided at an end of the bobbin or on the bobbin f holder, to thereby achieved yarn grasping and cutting a of the yarn. Since the yarn is being traversed at a reduced speed, it is taken-up in a spiral form having a small pitch angle from the end of the bobbin towards its central portion to form a transfer .tail. This commencement of the take-up operation is detected by means of a photoelectric tube or other known means,

and in response to this detected signal, the traverse means is restored to the position upon normal take-up operation and also the traverse frequency is also restored to the frequency upon normal take-up operai tion. ln addition, simultaneously with the commencement of take-up operation of the yarn, the power supply for the accelerating electric motor is switched off, and the take-up operation is achieved according to a.

surface. frictional drive system while pressing the unwound bobbin against the drive roll. As described,

since the yarn transfer is carried out as the yarn is being taken-up on the fully wound bobbin while continuing the traverse of the yarn without disengaging the yarn from a traverse guide, the tension in the yarn can be maintained even upon yarn transfer and the yarn would not wind itself round the drive roll or the Godet roll. In addition, since the peripheral velocity of the unwound bobbin upon engaging with the yarn can be adjusted to make the relative movement between the yarn grasping device and the yarn to a most suitable one for making the yarn wind itself round the bobbin, the yarn transfer operation can be carried out in a reliable manner.

Furthermore, since the traverse speed is lowered during the yarn transfer operation, a transfer tail can be formed simultaneously with the winding of the yarn itself round the bobbin, and by restoring the traverse means to the position for normal take-up operation after the formation of the transfer tail has been confirmed, the yarn wound not be taken-up as overlapped on the initially formed transfer tail, and so a perfect transfer tail can be obtained. During the yarn transfer operation, the fully wound bobbin is rotating due to its own inertia, as it is separated from and not driven by the drive roll. However, in order to maintain the tension in the yarn in a more reliable manner, the bobbin driving motor is actuated to prevent the fully wound bobbin from being decelerated, during the period of 2 3 seconds from the separation of the fully wound bobbin from the drive roll up to the completion of the yarn transfer operation.

While it is desirable for carrying out the aforementioned operations to have an electric power supply which can independently adjust the peripheral velocities of the drive roll, unwound bobbin and fully wound bobbin, respectively, the power supplies for driving the drive roll, unwound bobbin and fully wound bobbin could be provided in common, if the outer diameter of the drive roll and the outer diameter of the unwound bobbin are appropriately selected (the outer diameter of the drive roll being selected somewhat smaller than the outer diameter of the unwound bobbin or than twice as large as the latter), and if the number of poles,

output power and torque performance of the bobbin accelerating electric motor are appropriately selected.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A method of transferring a yarn from a fully wound take-up bobbin to an unwound bobbin in an automatic take-up motion of a peripheral drive turret type, characterized by the steps of, independently rotating said unwound bobbin, separating said fully wound bobbin from a drive roll peripherally driving said fully wound bobbin, independently rotating said fully wound bobbin, lowering a traverse speed of the yarn to a speed that is most suitable for formation of a transfer tail, displacing a traverse cam roll with a pneumatic cylinder or other known means so as to make the yarn contact with a yarn grasping device provided at an end of the unwound bobbin or on a bobbin holder of the unwound bobin grasping the yarn with said grasping device, cutting off the yarn between said yarn grasping device and said fully wound take-up bobbin by means of a cutter associated with said yarn grasping device to take-up the yarn on said unwound bobbin, restoring the traverse cam roll to its normal position simultaneously with the formation of the transfer tail, accelerating the traverse speed of the yarn up to a speed for normal take-up operation, pressing the unwound bobbin against a driving roll, switching off a power supply to the means independently driving the bobbins, and rotating said unwound bobbin with said driving roll for carrying out the take-up operation.

Claims

1. A method of transferring a yarn from a fully wound take-up bobbin to an unwound bobbin in an automatic take-up motion of a peripheral drive turret type, characterized by the steps of, independently rotating said unwound bobbin, separating said fully wound bobbin from a drive roll peripherally driving said fully wound bobbin, independently rotating said fully wound bobbin, lowering a traverse speed of the yarn to a speed that is most suitable for formation of a transfer tail, displacing a traverse cam roll with a pneumatic cylinder or other known means so as to make the yarn contact with a yarn grasping device provided at an end of the unwound bobbin or on a bobbin holder of the unwound bobin grasping the yarn with said grasping device, cutting off the yarn between said yarn grasping device and said fully wound take-up bobbin by means of a cutter associated with said yarn grasping device to take-up the yarn on said unwound bobbin, restoring the traverse cam roll to its normal position simultaneously with the formation of the transfer tail, accelerating the traverse speed of the yarn up to a speed for normal take-up operation, pressing the unwound bobbin against a driving roll, switching off a power supply to the means independently driving the bobbins, and rotating said unwound bobbin with said driving roll for carrying out the take-up operation.