US3203634A

US3203634A - Suction device for removing a starting length of yarn from a textile coil

Info

Publication number: US3203634A
Application number: US243546A
Authority: US
Inventors: Furst Stefan
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-12-11
Filing date: 1962-12-10
Publication date: 1965-08-31
Anticipated expiration: 1982-08-31
Also published as: DE1276523B; CH407832A; GB1025756A

Description

5 FURST 3,203,634 SUCTION DEVICE FOR REMOVING A STARTING LENGTH OF YARN FROM A TEXTILE COIL Filed Dec. 10, 1962 2 Sheets-Sheet 1 Aug. 31, 1965 s. FURST 3,203,534

SUCTION DEVICE FOR REMOVING A STARTING LENGTH OF YARN FROM A TEXTILE COIL 2 Sheets-Sheet 2 Filed Dec. 10, 1962 FIG. 4

FIG. 3

'even under most unfavorable conditions.

United States Patent v SUCTION DEVICE FOR REMGVING A STARTING 11 Claims. (c1. 242-18 My invention relates to devices for seeking and withdrawing a length of yarn from a coil of yarn in textile fabrication.

To afford or facilitate automatic operations of this kind, bobbins and other yarn coils are often provided with a reserve winding of a few turns of yarn wound upon the tip of the coil core (tip bunch) or upon the core foot (foot bunch). The reserve winding can be seized and pulled off by a gripper, air-suction device, airblowing device, or the like means. However, it is not always possible to employ yarn coils with such a reserve winding. Although, in principle, a suction device could also be used to seek and withdraw a starting end of yarn from the peripheral surface of the yarn body proper, rather than from a reserve winding on the core, the latter mode of operation makes it ditficult to properly limit the length of yarn thus pulled off. In contrast thereto, when a reserve winding is subjected to suction, the length of yarn withdrawn can be limited by placing a stop member against or into the surface of the main body of yarn,

particularly at the conical front portion of that body. The yarn end can then be unwound only up to the stop member. When a reserve winding is not available, such a stop member cannot be used, or it must be placed so far to the rear on the yarn body that the length of yarn withdrawn in front of the stop member is always long enough, even under most unfavorable conditions. This has the consequence that the length of yarn pulled off is often so extreme as to involve excessive losses.

To avoid these disadvantages, it has been proposed to limit the interval of time in which the current of suction air is made effective. This, however, must take into account that air-flow speeds of about 50 to 100 meters per second are needed for reliably tearing a starting end of yarn away from the main yarn body to which it tends to adhere, and for conveying the yarn end to a predetermined other location. Since the adhesion of the starting end to the wound body of yarn is different from coil to coil, depending upon particular storage conditions and upon the roughness or other constitution of the particular yarn, the suction device must remain active until the starting end of the yarn is reliably removed from the coil body This require ment, at the high air-flow velocities, also results in often withdrawing from the coils an excessively great length of yarn, thus rendering the operation highly uneconomical.

It is an object of my invention to obviate the above- 'mentioned deficiencies of the suction devices heretofore known for pulling a starting length of yarn from bobbins and other yarn coils. More specifically, it is an object to provide a suction device which, with the aid of relatively simple means, affords a reliable removal of the starting end from the yarn coil regardless of whether or not the coil is provided with a reserve winding such as a tip bunch, and which nevertheless limits the pulled-off end to a desired length.

To this end, and in accordance with my invention, I mount a sensing or measuring member in the suction range of a suction tube whose open end portion surrounds the coil with the necessary clearance for pulling the yarn end by suction into the tube, the sensing or measuring member being responsive to the presence of yarn in the suction tube at a given location corresponding essentially to the desired length of yarn to be pulled off the coil. The sensing member then issues a signal, preferably electrically, thus rapidly and accurately indicating the moment when a suflicient amount of yarn is pulled away from the textile coil and into the suction device. As soon as the signal issuing from the sensor is efiective, suitable means are made active to prevent a further amount of yarn from being pulled into the suction tube.

According to another feature of my invention, we connect the sensing member with a stop device that prevents further withdrawal of yarn from the coil. Such a stop device may consist, for example, of clamping means that clamp the yarn to the coil in opposition to any further suction effect. According to another feature of my invention, however, it is preferable to prevent further withdrawal of yarn by providing the suction tube with control means that substantially interrupt or shut off the suction pressure in response to the signal issuing from the sensing member. Thus, the signal can be employed for disconnecting or stopping the suction-pressure generator relative to the suction tube. However, since generally a single negative-pressure source is employed for a plurality of suction nozzle tubes, it is preferable to provide each suction tube with a controllable valve whose actuating means are connected to the sensing member so as to substantially throttle or shut oil the suction pressure when the sensing member responds to presence of yarn at the above-mentioned location within the suction tube.

Many machines for fabrication of textile coils, for example automatic yarn-package winding machines, make it desirable that the starting end of the yarn be not only seized and pulled off the coil, but that the starting end be thereafter carried away to a given other location in the machinery. This is done, as a rule, by moving the suction nozzle, after it has pulled the starting end of yarn from the coil, in a given direction so that the length of yarn seized by the suction nozzle reaches the given other location. For example, when a number of cops are successively supplied to a winding machine to be wound into a larger yarn package, the starting end from each new cop fed to a winding station is first seized by a suction-nozzle tube which withdraws a given length of yarn, and the tube is then shifted or turned away from the cop to place the yarn end into the action range of a knotter. Such machines are illustrated and described, for example in US. Patents Nos. 2,936,130, 3,034,737, 3,059,865 and 3,059,867, all assigned to the assignee of the present invention.

Referring to suction devices for yarn-package winding machines of the type just mentioned, it is another object of my present invention to afford not only a reliable withdrawal of a limited length of yarn from the coil but to simultaneously prevent the yarn from gliding out of the suction tube after the current of suction air is stopped or during any following conveying travel of the nozzle end of the suction tube from the coil to the knotter or other location.

According to another feature of my invention, therefore, the above-mentioned yarn-presence responsive sensor is also coupled or connected with a clamping device which mechanically holds the-withdrawn length of yarn in the suction tube so that, when the suction current is interrupted or discontinued, the yarn is simultaneously clamped fast in the tube.

According to another, preferred feature, a valve mechanism, controlled by the above-mentioned yarn-responsive signals of the sensor, is simultaneously designed as part of a clamping device which automatically clamps the yarn to the suction tube when throttling or stopping the suction current.

According to still another feature of my invention, more specific than the one last mentioned, the controllable valve for stopping the suction current is mounted in the vicinity of the sensing member. In this case, the interval of time elapsing from the response of the sensing member to the closing of the valve is sufficient, on account of the high air velocity, to place the yarn end into the clamping range of the valve with the result that the yarn end becomes clamped by the'valve mechanism itself.

Applicable as sensing or measuring member for ascertaining the presence of yarn in the suction tube, are any sensing components of known type, for example mechanical or electrical feelers, electronic or photoelectric yarn feelers or other proximity-type sensors. Applicable as electric or electronic yarn feelers, for example, are the known electronic yarn cleaners that consist essentially of a capacitor arrangement and respond to the change in capacitance effected by the presence of yarn. Such capacitive sensors release an electric pulse due to change in capacitance, immediately upon passage of yarn through the sensing capacitors or their immediate vicinity. Suitable as photoelectric yarn feelers are photocells in conjunction with light sources of any of the variety of types commercially available for such purposes. A portion of the suction tube can be made transparent, so that the light source can be mounted on one side of the suction tube and the photoelectric cell on the diameterically opposite side.

According to still another feature of my invention, the reliability of performance is further improved by giving the nozzle portion of the suction tube a curved contour that guides the withdrawn length of yarn to the location of the sensing member. According to a preferred and more specific feature, the suction tube is given a curved shape, for example approximately U-shape, and is provided with a slot extending along the inner bight of the tube at the place of the smallest diameter of curvature. The yarn end sucked away from the coil is then pulled into the slot so that the yarn end extends along a geometrical chord. By mounting the sensing member in the vicinity of this chord and hence in the bight space of the curved suction tube, a reliable performance is secured because the yarn end is constrainedly guided to pass along a predetermined path close to the sensing member.

The above-mentioned objects, advantages and features of my invention, said features being set forth with particularity in the claims annexed hereto, will be apparent from, and will be described in, the following with respect to the embodiments of devices according to the invention illustrated by way of example on the accompanying drawings, in which:

FIG. 1 shows in longitudinal section a device equipped with a mechanical yarn feeler acting electrically upon a combined valve and clamping device.

FIG. 2 shows, also in longitudinal section, a suction device equipped with an electric sensing member of the capacitive type.

FIG. 3 is a horizontal section through the suction tube according to FIG. 2, the section being taken midway through the bight of the U-shaped tube portion.

FIG. 4 shows, by a cross section similar to that of FIG. 3, a device generally in accordance with FIG. 2 but equipped with a photoelectric sensing member; and

FIG. 5 shows schematically a device according to FIG. I mounted for rotary travel of the suction tube to shift the entrained length of yarn away from the coil.

The same reference characters are applied in all illustrations to corresponding elements respectively.

Denoted by 1 in FIG. 1 is the textile coil, shown as a cop, whose starting end is to be sought and pulled off. The coil 1 is held in proper position by any suitable holding means, depending upon the particular apparatus or machine of which the suction device is to form part.

For example, according to FIG. 5, the tubular core or quill of coil 1 is speared upon a mandril 1b which is mounted on a hub 1c, as is the case in the coil-winding machines according to the above-mentioned patents. The flaring nozzle end of a suction tube 3 surrounds the tip 2 (FIG. 1) of the coil 1 with sufficiently wide peripheral clearance to permit an intensive current of air, represented to arrows 4, to pass into the suction tube along the front portion of the yarn body on the coil. The other end of the tube is connected to a suitable source of negative pressure. For example, according to FIG. 5, the other end of the tube is mounted on, and communicates with, a pipe 3b perpendicular to the plane of illustration and serving as a conduit for connecting the suction tube 3 to a blower or pump that produces the vacuum pressure. The pipe 3b also constitutes a pivot that permits turning the suction tube 3 away from the cop 1 after the yarn end is withdrawn and clamped in the suction tube, thus conveying the yarn to a different location, as mentioned above.

During operation, the suction air passes along the conical surface portion of the body of yarn on coil 1 and thus entrains the starting end of yarn. The yarn end, thus being pulled into the suction tube, is wound from the coil over the tip 2 of the core. For guiding the yarn end on a predetermined path in the tube, the tube is U-shaped and is provided with a slot 5 in its inner bight at the location of the smallest radius of curvature. The yarn end F pulled into the suction tube is caught in the slot 5 and passes between the

ends

5a and 5b of the slot along a straight path constituting a geometrical chord with respect to the inner bight curvature of the suction tube. Located in the inner bight space between the legs of the U- shape is a sensing member which in the embodiment of FIG. 1 consists of a mechanical yarn feeler 6 pivoted at 8 to a mounting structure that is fastened to the suction tube 3. The feeler 8 is biased counterclockwise by a spring 7 toward a fixed stop 9. When the yarn F passes through the slot 5, it engages the feeler 6 and turns it clockwise. A movable electric contact 10 of the yarn feeler 6 then engages a stationary contact 11. This closes an electric circuit from a current source 12 through an electromagnet 13. The magnet 13, when thus energized, attracts its armature 14 in opposition to the force of a spring 15 and causes a linking rod 16 to turn a crank arm 17 on the shaft 18 of a valve member 19. As a result, the valve member turns from the open position shown by broken lines to the closed position shown by full lines. In the closed position of the throttle valve the end of yarn F is clamped between valve member 19 and the adjacent wall of suction tube 3.

Consequently, as soon as the starting length of yarn passing through the slot 5 actuates the feeler 6, the valve member 19 commences to operate and to throttle the suction current air until it becomes ineffective or substantially stopped. When the latter condition is reached, the withdrawn length of yarn is sufiiciently long to be clamped fast. Hence the yarn end remains held in the suction device independently of any continuance of the suction air current. If the suction device is subsequently used for conveying the yarn end to a dilferent location, for example by turning the suction tube 3 about its pivot to the broken-line position shown in FIG. 5, or also by additionally moving the hub with mandril 1b and cop 1 counterclockwise to a different angular position, the yarn end remains attached to the suction tube. If desired, an electric switch may be interposed in the energizing circuit of the magnet 13 so that, by subsequently opening the switch, the magnet is deenergized for returning the valve member 19 under the force of spring 15 to the open position. Any yarn residue would then be eliminated by the air current.

In the embodiment of FIG. 2, the nozzle portion of the suction tube 3 extends longitudinally over a larger portion of the yarn coil than in FIG. 1, it being assumed that in this case the coil is not completely filled with yarn so that the wound body of yarn no longer reaches up to the tip 2 of the tubular core. In such cases it may happen that the withdrawal of the starting end in a device according to FIG. 1 encounters trouble because the yarn end can no longer be unwound from the body of yarn by pulling it over the tip. For that reason, the suction tube 3 in the device shown in FIG. 2 is given a curved contour which curves upwardly at 3a behind the straight nozzle portion 3b before curving downwardly in U-shaped configuration. The upward portion of the curvature is such that the point near the locality 5a where the yarn end rest against the inner bight of the suction tube is substantially located on the longitudinal axis 1' of the coil 1. As a result, the yarn end F can be unwound from the coil body by pulling the yarn over the tip 2 despite the fact that the yarn end comes from the body of yarn located relatively remote from the tip.

The device according to FIG. 2 is provided with a slot 5 in the bight portion of the suction tube 3 in the same manner as in the embodiment of FIG. 1, so that when the yarn end extends through the slot it forms a chord with respect to the inner curvature of the suction ube. At the slot ends 5a and 5b the wall of the tube, consisting of metal or synthetic plastic, is provided with respective covers to eliminate sharp edges and reduce the friction, thus reducing the stresses and wear imposed upon the yarn at these places. vThe .covers may consist of rubber or plastic, for example.

The sensing member 21, mounted on the suction tube 3 between the legs of the U-shape, consists essentially of an electric capacitor structure of the kind known and used for electrostatic yam-cleaning or slob-catching purposes. The yarn F extends between or along the capacitor electrodes, as apparent from FIGS. 2 and 3, thus changing by its presence the capacitance in a suitable electric or electronic measuring circuit for performing the desired signal or control operation, for example for energizing an electromagnet 13 to actuate a valve and clamping mechanism as described above with reference to FIG. 1.

In the embodiment according to FIG. 4, the signal in response to the presence of yarn in the slot 5 is produced by a photoelectric yarn feeler. In the illustrated example the yarn feeler comprises a light source, such as a light bulb 22, with an optical lens 23, both mounted in a housing 24 that permits a beam of light to issue through an aperture at the location occupied by the yarn F when the yarn is located in the slot 5. Mounted on the opposite side of the slot is a photoelectric cell 25 connected by the leads 26 to an electric circuit so that the current flowing in the circuit is modified when the yarn F enters into the beam of light issuing from the source 22. This change in electric current can be employed, for example, to control the magnet 13 as described with reference to FIG. 1.

It will be noted from the drawings that the curved tube structure in each of the embodiments defines a location of minimum curvature radius spaced from the open end portion of the tube, and that the sensing member in each embodiment is located adjacent said location.

Suction devices according to my invention are suitable generally for seeking, seizing and withdrawing a starting length of yarn from textile coils for any yarn fabricating or textile manufacturing purposes. Of particular advantage, however, is the invention in conjunction with automatic yarn-package winding machines that are to operate with yarn-supply coils without tip bunch or similar reserve winding. Thus, in a cheese-winding or cone-winding machine as illustrated and decribed in the above-mentioned Patent No. 2,936,130, the suction device according to the present invention is readily applicable in lieu of the one denoted by 13, in the patent.

To those skilled in the art it will be obvious upon a study of this disclosure that my invention permits of a variety of modifications and can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of my invention and within the scope of the claims annexed hereto.

I claim:

1. A suction device for seeking and removing a starting length of yarn from a yarn coil, comprising a curved suction tube structure having an open end portion surrounding, when in operation, the coil with clearance for pulling the yarn end by suction current into said tube structure, said tube structure defining a given location of minimum curvature radius spaced from said open end portion, said structure having air guiding means for urging the yarn end to said given location, a sensing member mounted adjacent said location of said tube structure and responsive into a responded condition upon presence of yarn at said location, and signal responsive means connected to said sensing member to be controlled by said member when said member is in said responded condition for substantially terminating the suction current in said end portion when a sufiicient length of yarn is removed from the coil.

2. A device according to claim 1, said air guiding means including a curved contour of said tube structure defining a bight for guiding the yarn to said location, said location being at the inner side of said bight, said signal responsive means comprising stop means connected to said sensing member for actuation by response of said member into said responded condition to prevent further removal of yarn from the coil.

3. A suction device for seeking and removing a starting length of yarn from a yarn coil, comprising a curved suction tube structure having an open end portion for surrounding, when in operation, the coil with clearance for pulling the yarn end by suction into said tube structure, said tube structure defining a given location of minimum curvature radius spaced from said open end portion, said device having air guiding means forming part of said tube structure for urging the yarn end to said given location, a sensing member mounted adjacent said location of said tube structure and responsive into a responded condition upon presence of yarn at said location and movable into said responded condition when a sufficient predetermined length of yarn is pulled into said tube structure, suction control means in said tube structure, and means connecting said control means to said sensing member for actuating the latter upon movement of said sensing member into said responded condition.

4. A suction device according to claim 3, said suction control means including yarn clamping means for fastening, when active, the pulled-cit yarn end to said tube structure.

5. A suction device for seeking and removing a starting length of yarn from a yarn coil, comprising a curved suction tube structure having an open end portion for surrounding, when in operation, the coil with clearance for pulling the yarn end by suction into said tube structure, said tube structure defining a given location of minimum curvature radius spaced from said open end portion, said device having air guiding means forming part of said tube structure for urging the yarn end to said given location, a sensing member mounted adjacent said given location for issuing a signal when a sutiicient predetermined length of yarn is pulled into said tube structure, a suction control mechanism having a member movable to an active position in which said mechanism substantially shuts off the suction pressure in said tube portion, said suction control mechanism including clamping means for clamping the pulled-off yarn end against said tube structure, said movable member forming part of said clamping means so as to clamp the yarn simultaneously with shutting oft the suction pressure, and control means connecting said mechanism to said sensing member for actuating said mechanism under control by said signal.

6. A suction device for seeking and removing a starting length of yarn from a yarn coil, comprising a curved suction tube having an open end portion for surrounding, when in operation, the coil with clearance for pulling the yarn end by suction into said tube, said tube defining a given location of minimum curvature radius spaced from said open end portion, a sensing member mounted at said location for issuing a signal when a sufficient predetermined length of yarn is pulled into said tube, a controllable throttle valve in said tube, air guiding means forming part of said tube for urging the yarn end to a given location in said tube spaced from said end portion, and control means connecting said valve to said sensing member for controlling said valve in response to said signal to substantially shut off the suction pressure in said tube portion.

7. A suction device for seeking and removing a starting length of yarn from a yarn coil, comprising a suction tube structure having an open end portion surrounding, when in operation, the coil with clearance for pulling the yarn end by suction current into said tube structure, said tube structure having a curved contour defining an inner bight for urging the yarn end to a given location at said bight and spaced from said end portion, said tube structure having in said inner bight of said curved contour a slot to be traversed by the yarn end, said slot being positioned so as to define for the yarn end a path along a geometrical chord of the inner bight contour, a sensing member mounted along said geometrical chord in the inner bight space of said tube portion and movable into responded condition in response to presense of yarn along said chord, and signal responsive means connected to said sensing member to be controlled by said member in said responded condition when a suflicient length of yarn is removed from the coil.

8. In a suction device according to claim 7, said tube portion having a substantially U-shape, and said sensing member being fastened to said tube between the legs of the U-shape.

9. In a suction device according to claim 7, said sensing member comprising an electric switch having a movable feeler engageable with the yarn end in said slot.

10. In a suction device according to claim 7, said sensing member comprising an electric proximity switch responsive to presence of yarn in said slot.

11. A suction device according to claim 5, comprising an electric actuator electrically connected to said sensing member and mechanically engageable with said control mechanism for actuating the latter in response to said signal, said sensing member and mechanism and actuator being mounted on said suction tube.

References Cited by the Examiner UNITED STATES PATENTS 2,208,930 7/40 Kahlisch 242-35.6 2,338,914 1/44 Esser et al. 24235.6 2,780,908 2/57 Bechtler 5734.5 X 2,812,632 11/57 Tillet 5734.5

MERVIN STEIN, Primary Examiner.

RUSSELL C. MADER, Examiner.

Claims

1. A SUCTION DEVICE FOR SEEKING AND REMOVING A STARTING LENGTH OF YARN FROM A YARN COIL, COMPRISING A CURVED SUCTION TUBE STRUCTURE HAVING AN OPEN END PORTION SURROUNDING, WHEN IN OPERATION, THE COIL WITH CLEARANCE FOR PULLING THE YARN END BY SUCTION CURRENT INTO SAID TUBE STRUCTURE, SAID TUBE STRUCTURE DEFINING A GIVEN LOCATION OF MINIMUM CURVATURE RADIUS SPACED FROM SAID OPEN END PORTION, SAID STRUCTURE HAVING AIR GUIDING MEANS FOR URGING THE YARN END TO SAID GIVEN LOCATION, A SENSING MEMBER MOUNTED ADJACENT SAID LOCATION OF SAID TUBE STRUCTURE AND RESPONSIVE INTO A RESPONDED CONDITION UPON PRESENCE OF YARN AT SAID LOCATION, AND SIGNAL RESPONSIVE MEANS CONNECTED TO SAID SENSING MEMBER TO BE CONTROLED BY SAID MEMBER WHEN SAID MEMBER IS IN SAID RESPONDED CONDITION FOR SUBSTANTIALLY TERMINATING THE SUCTION CURRENT IN SAID END PORTION WHEN A SUFFICIENT OF YARN IS REMOVED FROM THE COIL.