Patent Application
20090064464
This application claims priority based on European patent application EP 07 017 492.5, filed Sep. 6, 2007.
The invention relates to devices and methods for compacting fiber flocks and more specifically to devices for compacting fiber flocks to form fiber flock mats.
Devices for compacting fiber flocks are usually designed as hopper-type feeds such as vibrating chute feeds. These feeds compact the flock-like fibers into a flock mat, which is then sent to, for example, a fleece forming system. Devices for compacting fiber flocks are known from, for example, EP 0 529 246 B1, DE 195 38 143 C2, and DE 299 24 648 U1.
These devices suffer from the disadvantages that the fiber flocks are often compacted in irregular fashion and that the compaction can be controlled to only a limited extent by adjustment of the machine parameters.
It is an object of the present invention to provide a device for compacting fiber flocks into a flock mat, by means of which a uniformly dense flock mat can be produced very quickly.
According to an aspect of the invention, the device for compacting fiber flocks into a flock mat comprises a means for supplying the fiber flocks, a discharge belt for carrying the compacted flock mat away, and two walls arranged opposite each other between the means for supplying the fiber flocks and the discharge belt. The two walls form the boundaries of an essentially vertical chute feed, which defines the transport direction of the fiber flocks. At least one of the walls is supported in such a way that its movement during each cycle comprises a component in the transport direction of the fiber flocks and a component in the direction transverse to that transport direction.
With this arrangement, it is possible not only to move the flocks downward through the chute feed by means of vibratory movement but also to accelerate the compaction process by the guided movement of at least one wall, which moves first inward and then downward. This guarantees continuous deposition onto the discharge belt.
Both walls are preferably supported in such a way that, during each cycle, they can move in a predetermined manner, this movement comprising a component in the transport direction of the fiber flocks and a component transverse to that. As a result of this coordinated, synchronized movement, the compacting effect in the direction toward the discharge belt is increased.
To improve the discharge of the compacted fiber flocks, the two walls are slightly offset from each other in the transport direction by the use of two offset discharge rollers at the bottom end of the vertical chute feed.
In a preferred embodiment, the upper area of at least one wall is supported pivotably on an upper cam arrangement. As a result, the direction in which the wall moves, namely, in the transport direction of the fiber flocks and also transversely thereto, is defined in a simple manner. Similarly, the lower area of at least one wall is rigidly supported on a lower cam arrangement. In addition, the upper cam arrangement preferably comprises a longer stroke than the lower cam arrangement, as a result of which an elliptical movement is produced in the upper area of the wall, whereas only a circular movement is generated in the lower area.
In one embodiment, the upper cam arrangement includes a stationary but rotating upper shaft, which drives an upper cam disk rigidly connected to the upper shaft. The upper cam arrangement also includes an upper con rod, which is connected rotatably at one end to the upper cam disk and at the other end pivotably to the respective wall by way of a connecting pin permanently connected to the upper con rod.
In an other embodiment, the lower cam arrangement comprises a stationary but rotating lower shaft, which drives a lower cam disk rigidly connected to the lower shaft, and a lower con rod, which is connected at one end to the lower cam disk and at the other end rigidly to the wall.
To achieve the different types of strokes mentioned above, the upper cam arrangement is preferably designed in a similar manner, wherein the diameter of the cam disk is appropriately larger, and the upper con rod is connected pivotably to the wall by a connecting pin permanently connected to the upper con rod.
In this arrangement, the upper cam arrangement and the lower cam arrangement are connected to each other so that their movements can be synchronized It is also contemplated that the cam arrangements of the two walls have different phase positions to allow alternative movement. In an especially highly developed embodiment, a control unit is provided, which serves to coordinate or otherwise modify the movements of all the cam arrangements of the device with each other. As a result, standard sequences can be predefined, but it is also possible, for example, to adjust the rotational speed of the camshafts as appropriate in response to the results of a weight measurement of the flock mat which has been produced.
Additional features and advantages of the present invention can be derived from the following description, which refers to the drawing.
In the example shown here, the two walls 10 of the chute feed are each connected at the top to an upper cam arrangement 18 and at the bottom to a lower cam arrangement 20. Upper cam arrangement 18 has a stationary but rotating upper shaft 22, which drives an upper cam disk 24 connected rigidly to upper shaft 22. In addition, upper cam arrangement 18 has an upper con rod 26, which is connected to upper cam disk 24 preferably by way of a ball bearing (not shown). Upper con rod 26 is connected to wall 10 through a connecting pin 28 thereby creating a pivotable connection between upper con rod 26 and wall 10.
In a similar manner, lower cam arrangement 20 comprises a stationary lower shaft 32, which is connected rigidly to a lower cam disk 34. Lower con rod 36 is also installed around, and connected to, the lower cam disk 34 preferably by way of a ball bearing at one end. At the other end, Lower con rod 36 is rigidly connected to a corresponding section of wall 10. Upper shaft 22 and lower shaft 32 are driven in the same direction and thus move wall 10 by way of upper cam arrangement 18 and lower cam arrangement 20 along an essentially orbiting path with one component in the transport direction of the fiber flocks, i.e., vertically downward in the present example, and with one component transverse to the transport direction of fiber flocks 4, that is, in such a way as to narrow the width of chute feed 8. The shafts of the other wall rotate in the opposite direction.
Because the diameter of the upper cam disk 24 is larger than that of lower cam disk 34, and because upper cam arrangement 18 is pivotably supported on wall 10, wall 10 can execute a longer transverse stroke at upper cam arrangement 18 than it does at lower cam arrangement 20. As a result, flock material 4 is particularly loose near cam arrangement 18 and is pressed together over a greater transverse distance as it passes into the lower area of chute 8 near cam arrangement 18. Accordingly, greater compaction of fiber flocks 4 may be achieved as fiber flock 4 moves through chute feed 8 from an area near cam arrangement 18 toward cam arrangement 20. This effect can be intensified by narrowing chute feed 8 in the bottom area by having walls 10 slant toward each other.
Because walls 10 are preferably designed as perforated plates, and can include a set of small, downward-pointing shingles or pointed members, the component of the cam movement acting in the transport direction of fiber flocks 4 can achieve or intensify the ability of walls 10 to carry fiber flocks 4 through chute feed 8. Such movement also provides the ability to compact fiber flocks 4 vertically in the direction toward the outlet of chute feed 8.
Although a specific embodiment of the invention has been described in detail on the basis of the present example, various alternative designs or modifications are also possible. For example, chute feed 8 can also be slanted; two cam disks 24 and 34 can be of the same size; and only one of walls 10 can be movable, the other being stationary. There are also various ways in which cam arrangements 18 and 20 can be designed, as will be obvious to the expert. The important point in all cases is the possibility of a cyclical movement, which comprises both a component in the transport direction of fiber flocks 4 through chute feed 8 and a component transverse to that direction of movement of fiber flocks 4. For this purpose, it is possible to use circular movements, elliptical movements, or even rectangular movements.
In the present example, an elliptical movement is obtained for upper wall area 10, whereas the lower wall area 10 executes a circular movement. Here, too, many different modifications are possible. Two cam arrangements 18, 20 can easily comprise other types of eccentricities and can be in different phase positions with respect to each other in preferred embodiments.
In a one such design, upper shaft 22 and lower shaft 32 are connected, for example, by chains or toothed belts. It is also possible and contemplated herein for each shaft to have its own separate drive.
It may be advantageous to provide a control unit 42, which controls shafts 22, 32 and which can also be responsible for control of the movement of the discharge rollers 12, feed rollers 2, and opening roller 6 in unison or independently based on the desired application and particular specifications of use. As a result, it is easy to influence the density of flock mat 4 thus produced. When an automatic control circuit is provided to correct for variations in weight, the weight of the flock mat which has been produced can be measured in any desired way, and this value can be used by the control unit to set or to adjust any of above parameters both before and during use of the compacting device.
The present invention therefore makes it possible to improve the production of flock mats in a simple cost effective manner.
While the invention is shown in several forms, it is not limited to those embodiments illustrated, but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07 017 492.5 | Sep 2007 | EP | regional |
