Claims
- 1. A yarn package traverse mechanism for a yarn winding machine, for winding a yarn package onto a bobbin having spaced-apart flanges, said mechanism comprising,
- a rotatable bobbin mount comprising a spindle for receiving said flanged bobbin, said spindle having an axis of rotation,
- a traverse screw and follower mounted in a traverse box, said traverse box being mounted in an immobile position on said machine, said traverse screw having a first reciprocating drive means and said follower being positioned by said traverse screw to reciprocate along the length of a yarn package,
- a traverse yarn guide pivotally mounted on said follower and extending over said yarn package, said yarn guide being adapted to pivot away from said axis in a direction perpendicular thereto,
- lifting means for determining the pivotal position of said yarn guide relative to said axis, said lifting means being independent of said bobbin and said spindle, said lifting means comprising a vertically displaceable member adapted to lift said yarn guide, and
- control means operatively connected with said lifting means, said control means being adapted to control movement of said yarn guide away from said axis during the winding of said package whereby a small gap is maintained between said traverse yarn guide and the package surface during winding of at least a part of said package, said control means thereby not allowing any part of said mechanism to contact said package surface.
- 2. A yarn package traverse mechanism as set forth in claim 1 said vertically displaceable member comprising
- a lifting bar mounted on said machine, said lifting bar being positioned to cooperate with said yarn guide for lifting said yarn guide away from said package axis, said lifting bar being adapted to move in an operative motion path, and
- said control means comprising a cam surface and a cam follower operatively cooperating with said lifting bar, said cam surface and cam follower cooperating to control the spaced position of said yarn guide relative to said package axis, as determined by the longitudinal position of said lifting bar in its operative motion path.
- 3. A yarn package traverse mechanism as set forth in claim 1, said vertically displaceable member comprising
- a lifting bar mounted on said machine, said lifting bar being positioned to cooperate with said yarn guide for maintaining said yarn guide in a spaced relation to said package surface, said lifting bar being adapted to move in an operative motion path, and
- said control means comprising
- a stepping motor operatively connected with said lifting bar, said motor being intermittently operable to change the position of said lifting bar at which it cooperates with said yarn guide and, thereby, to change the spaced position of said yarn guide, the operating position of said lifting bar being determined by its longitudinal position in its operating motion path.
- 4. A yarn package traverse mechanism as set forth in claim 3 said mechanism comprising
- at least one flange sensing member connected to said yarn guide, said flange sensing member being positioned to contact said bobbin's flanges at the end of each traverse stroke by said yarn guide, said stepping motor being operated intermittently in response to that contact.
- 5. A yarn traverse mechanism for a yarn winding machine adapted to wind yarn on a flanged bobbin, said mechanism comprising
- a traverse screw and follower mounted in a traverse box, said traverse box being mounted in an immobile position on said machine,
- a rotating bobbin mount comprising a spindle having an axis of rotation,
- a traverse yarn guide pivotally mounted on said follower for movement away from said axis in a plane perpendicular thereto, said yarn guide thereby being adapted to reciprocate along the length of said flanged bobbin for forming a yarn package thereon, said yarn guide comprising two fingers between which yarn is fed, said fingers being pivotally mounted on said follower and being capable of pivotal movement in a direction perpendicular to said axis together or independent of each other,
- lifting means for determining the instantaneous pivotal position of said yarn guide relative to said axis, said lifting means being independent of said bobbin and said spindle, said lifting means comprising a vertically displaceable member adapted to lift said yarn guide,
- control means operatively associated with said vertically displaceable member for maintaining a small gap between said guide fingers and the surface of said yarn package being wound on said bobbin so that no part of said yarn guide contacts the package surface, and
- means for moving the leading one of said guide fingers clear of said bobbin's flange at the end of each traverse stroke by said yarn guide so that the trailing one of said guide fingers may guide said yarn right up to that flange.
- 6. A yarn traverse mechanism as set forth in claim 5 said moving means comprising
- a fixed cam associated with said traverse box, said cam being adapted to be engaged by each leading guide finger for pivoting said leading finger to said position beyond the exterior periphery of said flange so that said leading finger may pass over said flange as said yarn guide completes a traverse stroke.
- 7. A yarn traverse mechanism as set forth in claim 6 further comprising
- flange sensing means mounted on each guide finger, each said flange sensing means being adapted to detect a bobbin flange proximate to said finger, the flange sensing means on said trailing guide finger causing a signal to be transmitted for reversing said traverse mechanism when said trailing finger's flange sensing means detects the proximity of a bobbin-flange.
- 8. A yarn traverse mechanism as set forth in claim 6 further comprising
- flange sensing means adapted to detect a bobbin's flange when proximate to said finger, said flange sensing means on said trailing guide finger causing a signal to be transmitted for reversing said traverse mechanism when said trailing finger's flange sensing means detects the proximity of a bobbin's flange.
- 9. A yarn traverse mechanism for a yarn winding machine adapted to wind yarn on a flanged bobbin, said mechanism comprising
- a rotating bobbin mount comprising a spindle having an axis of rotation,
- a traverse yarn guide support means and a yarn guide mounted on said machine, said traverse yarn guide support means including a yarn guide support member for reciprocal translatory movement parallel to said axis, said yarn guide being pivotally mounted on said support member for pivotal movement in a direction perpendicular to said axis, and said yarn guide having two guide fingers between which said yarn is located, the trailing guide finger in each traverse stroke being operable to cause yarn to be laid up to one flange of said bobbin,
- a displacement device cooperating with said yarn guide for alternately moving each guide finger to a position clear of a respective one of said bobbin's flanges, said displacement device being operable to so move the leading finger in a traverse stroke prior to or when said leading finger reaches a bobbin's one flange so that the trailing finger of said same traverse stroke may move to a position closely adjacent said bobbin's one flange,
- a flange sensing means connected to each guide finger on the inner edge of that finger, each flange sensing means being adapted to contact a bobbin flange when its associated finger is the trailing finger in a traverse stroke for transmitting a signal to cause that traverse stroke to be reversed,
- a carrying plate movably mounted on one of said guide fingers, the flange sensing means for said one finger being mounted on said carrying plate, said carrying plate having biasing means so as to be normally retained in an inoperative position at which its flange sensing means does not obstruct that flange sensing means mounted to the other of said guide fingers when that other guide finger's flange sensing means is in its normal position at which it is adapted to contact a bobbin flange, and
- a follower means connected to said carrying plate and operatively cooperating with deflector means on said other finger, said deflector means being adapted to move said carrying plate from its inoperative position to an open position at which said carrying plate's flange sensing means can contact a bobbin's flange, said deflector means moving said carrying plate to said operative position only when said other guide finger is displaced by said displacement device away from its normal position at which it is adapted to contact a bobbin flange, and said carrying plate being moved back to said inoperative position by said biasing means when said other guide finger is returned to its normal position.
- 10. A yarn traverse mechanism as set forth in claim 9, said displacement device comprising
- lifting means to move the relatively leading finger in each traverse stroke to a position beyond the exterior periphery of said bobbin's flange.
- 11. A yarn traverse mechanism as set forth in claim 9, said flange sensing means functioning to cause signals to be transmitted that operate to reverse the direction of the movement of said yarn guide lengthwise of the package, and to move it outwardly of the surface of the package to maintain a small gap between said yarn guide and said package surface.
- 12. A yarn package traverse mechanism for a yarn winding machine for winding a yarn package onto a bobbin having spaced-apart flanges, said mechanism comprising
- a rotatable bobbin mount comprising a spindle for receiving a said flanged bobbin, said spindle having an axis of rotation,
- a traversable yarn guide means comprising a yarn guide support means and a yarn guide extending over said yarn package, said yarn guide support means including a yarn guide support member for reciprocal translatory movement parallel to said axis, and said yarn guide being pivotally mounted on said support member for pivotal movement in a direction perpendicular to said axis,
- first reciprocating drive means for linearly displacing said support member and said yarn guide in a direction parallel to said axis,
- lifting means for determining the instantaneous pivotal position of said yarn guide relative to said axis, said lifting means being independent of said bobbin and said bobbin's spindle, said lifting means comprising a vertically displaceable member adapted to lift said yarn guide, and
- second drive means for vertically displacing said displaceable member relative to said support member, said yarn guide being progressively pivoted away from said axis as the diameter of said yarn package increases so as to maintain a small gap between said yarn guide and the surface of said yarn package during winding of at least part of said package, thereby avoiding contact between said yarn guide and said package surface.
- 13. A yarn package traverse mechanism as set forth in claim 12, said vertically displaceable member comprising
- a lifting bar in said machine positioned to cooperate with said yarn guide along said length of a yarn package for maintaining said yarn guide in a spaced relation to said package surface, and said second drive means comprising
- a stepping motor operatively cooperating with said lifting bar to change the position of the lifting bar in a direction normal to the direction of reciprocation of the yarn guide and thereby change the position of the said yarn guide so as to maintain the spaced relationship between the yarn guide and the package surface.
- 14. A yarn package traverse mechanism as set forth in claim 12, said yarn guide comprising
- two fingers between which yarn is fed, said fingers each being pivotally mounted on said support member, and said fingers each being capable of pivotal movement in said direction together or independently of each other, and
- means for moving the leading one of said fingers clear of said bobbin's flange at the end of each traverse stroke by said yarn guide so that the trailing one of said fingers may guide said yarn right up to that flange.
- 15. A yarn package traverse mechanism as set forth in claim 14 said moving means comprising
- a fixed linear cam means adapted to be engaged by each leading guide finger for pivoting said leading finger to a position beyond the exterior periphery of said flange to that said leading finger may pass over said flange as said yarn guide completes a traverse.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 8614605 |
Jun 1986 |
GBX |
|
IMPROVEMENTS IN AND RELATING TO YARN WINDING MACHINES
This application is a continuation of application Ser. No. 062,179 filed June 2, 1987, now abandoned.
This invention relates to yarn winding apparatus. By the term "yarn" we wish to include natural and synthetic yarns and filaments as well as wire.
Existing winders include a yarn laying mechanism which may, for example, be in the form of a traverse guide screw or cam and a yarn guide which is caused, by engagement of a follower with the screw or cam, to reciprocate or traverse along the length of a yarn package e.g. a bobbin to lay the yarn evenly on the surface of the package. There are various other ways of driving the yarn guide, such as scrolls, cams, belts and chains.
If the bobbin, for example, has end flanges then in order to lay the yarn, which may be in the form of a filament, close to the flanges the guide has to be positioned above the flanges so that it can pass thereover. Hence the length of the yarn from the traverse guide to the surface of the bobbin on which yarn is being laid is significant and can lead to a ridged unevenly wound package. Furthermore the yarn may not be laid close up to the flange of the bobbin with the result that the end windings may fall into a gap between the flange and the end of the windings.
While not being desirable to have too great a distance between the traverse yarn guide and the surface of the bobbin, it is also not desirable to have the traverse guide or associated sensing roller in frictional contact with the bobbin since this also results in an uneven package surface when winding certain materials e.g. fine mono-filament yarns.
If the yarn is wound unevenly unwinding problems due to yarn jerking and sticking may arise causing uneven tension in the yarn being unwound and even yarn breakage.
Such problems are substantially overcome by a yarn winding apparatus in accordance with the invention which comprises a yarn traverse mechanism including a traverse yarn guide which is caused to reciprocate along the length of a bobbin to be wound, to lay the yarn on the bobbin wherein the apparatus includes a mechanism to control the position of the traverse yarn guide relative to the axis of the package being wound so as to maintain a small gap between the traverse guide and the package surface during package formation, no part of the mechanism contacting the package surface.
Thus no sensor or the like is present to impose a drag on the package. The `small gap` between the yarn guide and the package is, for example, the thickness of the yarn and this gap removes problems caused by frictional drag of the yarn guide on the package. Furthermore the problems which occur if the yarn guide is significantly spaced from the package surface are avoided because of the structure of the yarn guide itself.
Preferably, the yarn guide is split to have two independently displacable fingers between which yarn is positioned. The relatively trailing part or finger in any particular stroke of the guide acts to cause the yarn to be moved fully to the flange of the bobbin because means are provided to displace the relatively leading guide finger on any particular stroke at or prior to the leading finger reaching the flange of the bobbin so that the trailing portion can reach, and lay yarn right up to, the flange.
The leading finger may be pivoted or retracted straight back from the bobbin but, preferably it is raised so as to enable it to clear the flange.
The means for lifting a guide finger may for example comprise a cam positioned on the winder adjacent each flange on the body which engages the relatively leading guide finger and which acts to pivot the leading guide finger upwardly at a position close to the flange so that that guide finger may pass over the top of the flange.
Alternatively the guide parts may each be formed or provided with a member to engage the flange of the bobbin in such a way to cause the respective guide part to be lifted over it.
In a further alternative the means may act to rotate the guide about a transverse axis so that the relatively leading finger is lifted as the guide rotates through 90.degree. allowing the other i.e. the trailing finger, to be moved up close to the flange of the bobbin. The guide may, for example, be rotated mechanically at the appropriate part of the traverse, or, alternatively, with such a guide, once it has passed beyond the mid-point of any one stroke, the angle of the yarn between the let off point and the point of laying on the bobbin surface may be such that the tension in the yarn will cause the yarn guide to rotate about a central pivot in effect lowering the trailing part of the guide and raising the leading part of the guide through a sufficient angle as the guide approaches the bobbin flange as to enable it to be pivoted fully to the required position when it engages the obstructing wall of the flange. This avoids other separate guide pivoting means.
Preferably the mechanism for controlling the position of the yarn guide relative to the axis of the package so that the yarn guide is in effect moved away from the axis as the package is being formed so as to maintain the small gap between the guide and the package surface, comprises a standard "stepping" motor which is operated intermittently to lift the yarn guide away from the package axis. The intermittent operation of the motor is preferably achieved by electric signals transmitted from a feeler, the operation of which will be described hereafter, which may, for example, be positioned to engage a flange of a flanged bobbin at the end of each traverse stroke.
The engagement of the flange and feeler causes a signal to be transmitted.
It is not essential that the small gap be present between the yarn guide and package surface throughout the full winding cycle. Apparently if the traverse guide rests on the surface of the package for example for the last few winding layers no noticeable ill-effect will occur. Neither is it essential for the width of the small gap to be maintained constant throughout winding.
Preferably the traverse box containing the screw and follower is maintained in a fixed position. Whilst this is convenient it requires a somewhat longer traverse guide finger and the longer and heavier fingers would increase frictional drag were they to rest on the surface of the package. When ridging of the package occurs this traverse guide would start to bounce significantly altering the yarn tension control and thus further exacerbating ridging. The invention is thus particularly useful for winders having fixed traverse boxes.
As the bobbin increases in diameter with the layers of yarn pressure increases on the flanges to the extent that they may become deformed outwardly and the distance between the flanges is varied. If a fixed traverse distance is employed then yarn could fall into the space at each end of the bobbin. After the bobbin is emptied a certain amount of restoration to its original shape occurs but this varies from bobbin to bobbin and so it is important that the distance of each traverse right from the very first layer is monitored and controlled. As previously mentioned feelers or detectors are provide which may be mounted on each guide finger to detect when the yarn reaches the flange. As well as transmitting a signal to a "stepping" motor to raise the level of the yarn guide relative to the surface of the package, the feeder also signals to the traverse guide mechanism to reverse and return to the opposite flange.
Such detector means may comprise a runner on the inner edge of each guide to contact the adjacent bobbin flange at the end of each traverse stroke when that guide part is the trailing finger and which transmits a signal to reverse the direction of guide drive and operate the "stepping" motor which raises the level of the yarn guide relative to the package surface.
In a preferred embodiment there is a pivotally mounted detector carrying a runner. The runner is rotated by the rotating flange to reduce friction and at the same time, the pressure on the runner causes the detector to pivot to send a signal to reverse the direction of the traverse movement of the yarn guide. Thus by means of this detective system the length of each traverse can vary if the distance between the bobbin flanges varies so that yarn will always be layed right up to the bobbin flange regardless of the thickness of the package.
US Referenced Citations (11)
Foreign Referenced Citations (8)
| Number |
Date |
Country |
| 48770 |
Apr 1977 |
JPX |
| 141479 |
Dec 1978 |
JPX |
| 557219 |
Nov 1943 |
GBX |
| 1002570 |
Aug 1965 |
GBX |
| 1356335 |
Jun 1974 |
GBX |
| 1403918 |
Aug 1975 |
GBX |
| 1434916 |
May 1976 |
GBX |
| 2127860 |
Apr 1984 |
GBX |
Continuations (1)
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Number |
Date |
Country |
| Parent |
62179 |
Jun 1987 |
|
Patent Grant
4884764
