Method for Doffing for a Spinning Machine and a Corresponding Doffer

Abstract

A method for removing full bobbins from spindles of a ring spinning machine and for setting down empty sleeves on the spindles using a doffer is disclosed. The doffer has a beam and a rotatable gripping device that is mounted on the beam and has a sleeve gripper and a bobbin gripper, wherein the doffer is arranged next to the ring spinning machine. The beam is raised vertically and the gripping device is extended from the beam over the full bobbin. The invention also relates to a doffer having the corresponding drives.

Description

FIELD OF THE INVENTION

The present invention relates to a method for removing full bobbins from spindles on a spinning machine and setting down empty sleeves on the spindles using a doffer. The invention also relates to a doffer for a ring spinning machine having a plurality of spinning stations.

BACKGROUND

Doffer apparatuses for spinning machines are well-known. The doffer apparatus usually has a plurality of gripping devices so that a gripping device is assigned to each spinning station. In many cases, such a gripping device has a gripper, which first removes a full bobbin from a spindle and sets it down on a journal on a conveyor belt, for example. Then the gripper grips an empty sleeve for example from a journal on a conveyor belt, and places it on the spindle. Between the removal of the bobbin and the placement of the sleeve, a beam on the doffer apparatus on which the gripping devices are arranged must be moved from the spinning station to the conveyor belt and back again to the spinning station. Because of the size of the doffer apparatus, this movement is usually time consuming, which causes spinning time to be lost.

To solve this problem, Swiss Patent CH 676724 describes a doffer apparatus having gripping devices, each of which is provided with two controllable gripping elements for gripping sleeves and bobbins. The gripping elements there are accommodated in a rotating disk driven by an adjusting drive. For a doffing operation, the first gripping element first grips an empty sleeve. Then the beam on the doffer apparatus moves the gripping devices together with the empty sleeves toward the spinning stations. At the spinning station, the second gripping element then removes the full bobbin from the spindle. Next, the adjusting drive rotates the rotating disk, so that the first gripping element is set down with the empty sleeve over the spindle. Then the first gripping element sets down the empty sleeve on the spindle. Once this is done, the spinning process can be continued. With this doffer apparatus, wide areas of the beam are avoided during the downtime of the spinning stations, which thus saves time. But one disadvantage of this doffer apparatus is that, in the direction of the longitudinal axis of the spinning machine, the gripping devices with the rotating disks require more space than what is available between two spinning stations on many modern spinning machines. Furthermore, the demand for space is increased in an unfortunate manner with this embodiment because the doffer tilts out at the side.

French Patent FR 589966 discloses a doffer double gripper, which picks up the completed bobbins/cops and sets the empty sleeves down. However, one disadvantage of this embodiment is the lower fastening of the sleeves/cops because this is a stability problem.

SUMMARY OF THE INVENTION

An object of the present invention is thus to create a method and a respective doffer apparatus which will allow a rapid doffing operation with restricted available space. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

The present objects are achieved by the features described and claimed herein.

The objects are achieved in particular by a method for removing full bobbins from spindles on a ring spinning machine and setting the empty sleeves down on the spindles using a doffer, wherein the doffer has a beam and a rotatable gripping device mounted on the beam with a sleeve gripper and a bobbin gripper. The doffer is arranged next to the ring spinning machine. The method comprises the following method steps:

(a) Gripping an empty sleeve with a sleeve gripper;
(b) Vertical raising of the beam;
(c) Extension of the gripping device from the beam over the full bobbin;
(d) Removing the full bobbin from the spindle with the bobbin gripper, rotating the gripping device and setting the empty sleeve down on the spindle;
(e) Retracting the gripping device toward the beam;
(f) Vertical lowering of the beam, and
(g) Placement of the full bobbin.

In particular, advantages are provided by a doffer having a beam and a rotatable gripping device mounted on the beam, and having a sleeve gripper and a bobbin gripper, wherein the doffer can also be arranged next to the ring spinning machine. The ring spinning machine comprises spindles, comprising a drive for vertically raising and lowering the beam, and a drive for extending and retracting the gripping device from the beam over the spindles.

The method according to the invention and the doffer according to the invention are advantageous because they are very space saving, and the machine is not made wider due to the lateral extension of the doffer. Furthermore, this is a very simple design.

In a first specific embodiment, the gripping device is pivoted outward from the beam in the horizontal direction. A simple joint is advantageously used here between the beam and the gripping device. In this case, after gripping the empty sleeve, the gripping device executes a rotational operation to thereby bring the bobbin gripper into the correct position for removing the filled bobbin.

In a second specific embodiment, the gripping device is pivoted outward from the beam in a pivoting movement of the gripping device, which is directed from below to obliquely upward. The gripping device here will execute a vertical offset to arrive at the working position for removing the full bobbin.

Depending on the space requirements, the rotational operation of the gripping device can be carried out before placement of the empty sleeves on the spindles, retraction of the gripping device toward the beam, wherein the gripping device is extended again over the spindles after the rotational operation. Alternatively, the rotational operation of the gripping device may also take place directly over the spindles without requiring any retraction and extension of the gripping device.

The bobbin gripper advantageously has a bobbin receptacle that is open toward the bobbin, and the sleeve gripper has a sleeve receptacle that is open toward the bottom and can be inverted over the bobbin and/or the sleeve for gripping it from above. The sleeve gripper and the bobbin gripper may be designed to be cylindrical or conical. The conical embodiment has the advantage that it provides a better hold of the sleeve and the bobbin, in particular when the two are pneumatically operated because the membrane is better adapted to the sleeve and the bobbin.

In an advantageous refinement of the invention, each gripping unit has two indicators by which the position of the rotational device is visible through a basic body. If a malfunction has occurred and the operator must reengage or equip a gripper unit, he can recognize the correct position from the outside. The two indicators must be set in alternation in the case of neighboring gripping units, so that the gripping units can be positioned and the missing gripping unit can be used correctly.

Finally, it is advantageous if the angle between the axis of rotation and the bobbin gripper axis is equal to the angle between the axis of rotation and the axis of the sleeve gripper. It is thus possible to achieve the result that, after rotation of the gripping unit, the positions of the bobbin gripper and the sleeve gripper are exactly switched, which then facilitates rapid placement of the empty sleeve.

In an advantageous specific embodiment, an axis of the bobbin gripper and an axis of the sleeve gripper may be arranged at an angle to one another, which is between 4° and 20°, especially preferably 15°. The angle between the axis of rotation of the gripping device and the axis of the bobbin gripper may also be equal to the angle between the axis of rotation and the axis of the sleeve gripper.

BRIEF DESCRIPTION OF THE FIGURES

Additional advantages of the invention are described in the following exemplary embodiments in which:

FIGS. 1a-j show schematic diagrams of a first specific embodiment of views of certain phases in changing from full bobbins to empty sleeves in the method according to the invention; and

FIGS. 2a-g show schematic diagrams of another specific embodiment of views of certain phases in changing from full bobbins to empty sleeves in the method according to the invention.

Only the features that are important for the invention are shown. The same features are provided with the same reference numerals in different figures. The directions of movement are indicated with arrows.

DETAILED DESCRIPTION

Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

FIG. 1 shows schematic diagrams of a first specific embodiment of views of certain phases in changing from full bobbins 7 to empty sleeves 5 on spindles 8 of a ring spinning machine according to the present method. The starting position for a changing operation according to the invention from bobbins 7 using the doffer apparatus 1 is illustrated schematically in FIG. 1a. The doffer apparatus 1 comprises a doffer beam 2 and a plurality of rotatable gripping devices 3 using two gripping elements 4₁, 4₂, so that a gripping device 3 is assigned to each spinning station on the ring spinning machine. The figures illustrate a gripping device 3 merely as an example, but several gripping devices 3 are arranged along the ring spinning machine. The multiple gripping devices 3 are mounted on the beam 2. Furthermore, the beam 2 can be moved in such a way that it can bring the gripping devices 3 into the positions relevant for the doffing operation in order to receive the empty sleeves 5 from the pin 6 of a conveyance system and deposit the full bobbins 7, and toward the spindles 8, in order to remove the full bobbins 7 and set down the empty sleeves. To do so, the gripping device 3 comprises as the first gripping element a sleeve gripper 4₁ and, as the second gripping element, a bobbin gripper 4₂. The bobbin gripper 4₂ is designed for gripping the full bobbin, and the sleeve gripper 4₁ is designed for gripping the empty sleeve. It is provided that the two gripping elements 4₁, 4₂ of the gripping device 3 can be rotated so that they mutually change positions.

The sleeve gripper 4₁ and the bobbin gripper 4₂ each have a sleeve receptacle that is open at the bottom and can be inverted over the bobbin 7 and/or the sleeve 5 for the purpose of gripping them. The two elements may be designed to be cylindrical or conical and may be operated pneumatically with a membrane. The diameter of the sleeve gripper 4₁ and the diameter of the bobbin gripper 4₂ are advantageously the same, in particular when the sleeve gripper 4₁ and the bobbin gripper 4₂ are designed to be essentially identical. In an advantageous specific embodiment, one axis of the bobbin gripper 4₂ and one axis of sleeve gripper 4₁ can be arranged at an angle to one another, which is between 4° and 20°, especially preferably 15°. The angle between the axis of rotation of the gripping device 3 and the axis of rotation of the bobbin gripper may also be equal to the angle between the axis of rotation and an axis of the sleeve gripper.

It is also the case that two neighboring gripping devices 3 can be rotated with a time lag between them. This is a particularly space-saving embodiment. Each gripping device 3 may then have two indicators, where the position of the rotational device is indicated through a base body.

In a first variant of the method according to the invention, the gripper beam 2 is first positioned so as to grip each of the empty sleeves 5 with a sleeve gripper 4₁ of the gripping devices 3 and to lift them up from a pin 6. As can be seen in FIG. 1b, the beam 2 is raised vertically according to the invention by a drive, which is not shown in greater detail here. FIG. 1c shows that the gripping device is then rotated about an axis of rotation in order to be able to receive the full bobbin 7 in a working position with the unoccupied bobbin gripper 4₂.

With the ring spinning machine shut down, the full bobbins 7 are gripped at their sleeves by the gripping elements of the gripping devices 3. The empty sleeves 5 are situated on the side of the spindles 8 facing away from the machine frame during this operation. In this method step, the gripping device 3 is extended and/or unfolded horizontally from the beam 2 (see arrow), in order to be positioned over the bobbins 7, and then is lowered (FIG. 1d). The horizontal pivoting and/or unfolding of the gripping device 3 takes place by way of articulated connections that are present between the beam 2 and the gripping device 3.

Next, the bobbin 7 is gripped and the gripper beam 2 is moved vertically upward in order to remove the bobbins 7 from the spindles 8. If the bobbins 7 are free of the spindles 8, then the gripping device 3 is rotated again by 180°, so that the empty sleeves 5 enter the position flush with the spindles 8. In this process step of rotation, the gripper can be moved and/or rotated into the position in FIG. 1b and shifted back to the spindle 8 (FIG. 1e). Alternatively, the gripper 3 can rotate over the spindles 8 (not shown in the figures). The empty sleeves 5 are again placed on the spindles 8 due to a vertical downward movement of the doffing beam 2. The end of this changing phase is illustrated in FIG. 1f. As shown in FIG. 1g, the doffer beam 2 is again retracted with the full bobbins 7 (cf. arrow). At the latest at this point in time, the ring spinning machine that has been stopped can be started up again.

FIGS. 1h-j show the lowering of the doffer beam 2 and the simultaneous rotation, so that the bobbins 7 are moved out of their waiting position into their subsequent position that is flush with the pin 6. In FIGS. 1i,j the gripper elements 4₂ holding the full bobbins 7 are in the position in which they are flush with the pin 6. By lowering the doffer beam 2 vertically and then releasing the gripping elements 4₂, the bobbins 7 are dispensed to the pins 6. Then the doffer 1 goes back to a resting position. The operation of changing full bobbins 7 for empty sleeves 5 is thus concluded.

FIG. 2 shows schematic diagrams of a second specific embodiment of views of certain phases in changing full bobbins 7 for empty sleeves 5 on a ring spinning machine in the method according to the invention. In FIG. 2a, the starting position is diagramed schematically for an operation of changing bobbins 7 with the doffer apparatus 1 according to the invention. The doffer apparatus 1 per se corresponds to the exemplary embodiment of FIG. 1, as described above, except for a second specific embodiment of setting down the gripping devices 3 over the spindles 8.

In this second variant of the method according to the invention, the gripper beam 2 is first positioned in such a way as to grip the empty sleeves 5, each with a sleeve gripper 4₁ of the gripping devices 3, and to lift them up from the pin 6 (FIG. 2a). As can be seen in FIG. 2b, the beam 2 is raised vertically according to the invention by a drive, which is not shown in greater detail. FIG. 2c shows that the gripping device 3, which is slightly inclined in FIG. 2b, is now brought into position over the bobbin 7 from underneath in a lateral tilting movement, to thereby be able to receive the full bobbin 7 in a working position with the unoccupied bobbin gripper 4₂. A corresponding articulated connection or a corresponding pivoting joint is present between the beam 2 and the gripping device 3. The movement is a pivoting of the gripping device 3, directed upward obliquely from the bottom with an offset contained therein.

The gripping device 3 is then tilted back and rotated into a retracted position (FIG. 2d) to then be extended again and tilted and to place the empty sleeve 5 on the spindle 8 (FIG. 2e). FIG. 2f then shows the renewed tilting back and FIG. 2g shows the full bobbin being deposited on the pin 6.

The method according to the invention and the doffer according to the invention are advantageous because they are very space-saving and do not cause the machine to be wider due to the lateral extension of the doffer. Furthermore, this is a very simple design.

LIST OF REFERENCE NUMERALS

• 1 Doffer, doffer apparatus
• 2 Doffer beam
• 3 Gripping device
• 4₁ Gripping element, sleeve gripper
• 4₂ Gripping element, bobbin gripper
• 5 Sleeve
• 6 Pin
• 7 Full bobbin
• 8 Spindle

Claims

1-15: (canceled)

16. A method for removing full bobbins from spindles on a ring spinning machine and for setting down empty sleeves on the spindles using a doffer, wherein the doffer has a beam and a rotatable gripping device mounted on the beam, the gripping device having a sleeve gripper and a bobbin gripper, and the doffer arranged next to the ring spinning machine, the method comprising the following sequential steps:

(a) gripping an empty sleeve with the sleeve gripper;

(b) raising of the beam vertically;

(c) extending the gripping device from the beam to a position over a full bobbin on a spindle at the ring spinning machine;

(d) removing the full bobbin from the spindle with the bobbin gripper, rotating the gripping device, and placing the empty sleeve on the spindle;

(e) retracting the gripping device toward the beam;

(f) lowering the beam vertically; and

(g) setting down the full bobbin from the bobbin gripper.

17. The method according to claim 16, wherein step (c) comprises a horizontal pivoting of the gripping device away from the beam, and further comprising a rotational operation of the gripping device carried out between the steps (a)-(b) and between the steps (f)-(g).

18. The method according to claim 16, wherein step (c) comprises a pivoting of the gripping device obliquely upward with an offset.

19. The method according to claim 16, wherein step (d) comprises retraction of the gripping device toward the beam before the rotational operation of the gripping device, wherein the gripping device is again extended over the spindle after the rotational operation, or the rotational operation of the gripping device of step (d) takes place with the gripping device located over the spindle.

20. The method according to claim 16, wherein the bobbin gripper has a bobbin receptacle that is open at the bottom and is inverted over the bobbin for gripping the bobbin from above, and the sleeve gripper has a sleeve receptacle that is open toward the bottom and is inverted over the sleeve for gripping the sleeve from above.

21. The method according to claim 16, wherein the sleeve gripper and the bobbin gripper are operated pneumatically.

22. The method according to claim 16, wherein adjacent ones of the gripping devices on the beam are rotated with a time lag between one another.

23. The method according to claim 16, wherein the gripping device has indicators that provide a rotational position indication of the gripping device through a base body of the gripping device.

24. A doffer system configured for arrangement alongside a ring spinning machine to remove full bobbins from spindles on the ring spinning machine and to set down empty sleeves on the spindles, the doffer comprising:

a doffer beam;

a gripping device rotatably mounted on the beam;

the gripping device further comprising a sleeve gripper and a bobbin gripper;

a drive configured with the doffer beam to raise and lower the doffer beam; and

a drive configured with the gripping device to extend and retract the gripping device relative to the doffer beam.

25. The doffer system according to claim 24, wherein the drive configured with the gripping device comprises one of a joint for horizontal pivoting of the gripping device away from the beam, or a joint for obliquely upward pivoting of the gripping device with an offset.

26. The doffer system according to claim 24, wherein the bobbin gripper comprises a bobbin receptacle that is open at the bottom and is inverted over the bobbin for gripping the bobbin from above, and the sleeve gripper comprises a sleeve receptacle that is open toward the bottom and is inverted over the sleeve for gripping the sleeve from above.

27. The doffer system according to claim 26, wherein the bobbin gripper and the sleeve gripper are cylindrical or conical.

28. The doffer system according to claim 26, wherein the bobbin gripper and the sleeve gripper comprise a same diameter.

29. The doffer system according to claim 24, wherein an axis of the bobbin gripper and an axis of the sleeve gripper are at an angle to one another between 4° and 20°.

30. The doffer system according to claim 24, wherein an angle between an axis of rotation of the gripping device and an axis of the bobbin gripper is equal to an angle between the axis of rotation of the gripping device and an axis of the sleeve gripper.