Textiles: fiber preparation – Working – Carding
Reexamination Certificate
2001-01-25
2002-03-12
Calvert, John J. (Department: 3765)
Textiles: fiber preparation
Working
Carding
C019S0650CR, C019S10600R
Reexamination Certificate
active
06353973
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a calender, particularly for webs of textile fabric, non-woven fabric, or synthetic fabric, with a frame and a first roll, a second roll and a third roll mounted in the frame, wherein the third roll forms during operation a single nip either with the first roll or with the second roll.
2. Description of the Related Art
A calender of the above-described type is sold by Kleinewerfers Textilmaschinen GmbH in the form of a three-roll calender with rolls arranged one above the other. The nip is in this calender formed either between the upper roll and the middle roll or between the lower roll and the middle roll. The two different pairings of rolls are necessary in order to be able to switch over as soon as possible and without major reassembly from one manner of treatment to another manner of treatment. For example, it may be necessary to treat the fabric web with different surface qualities of the upper and the lower rolls. Another situation occurs when it is desired to change the treatment temperature of the fabric web. Since the temperature change in the heated roll can be carried out only at about 1° C. to 2° C. per minute in order to avoid undue thermal stresses, a temperature change of 40° C. will take a relatively long time. On the other hand, if it is possible to change to a roll which already has the required temperature, the time required for changing between the two types of treatment is drastically shortened.
Consequently, in the known calender, the travel path of the fabric web is changed when changing from one manner of treatment to another. Thus, if the fabric web has been fed to the upper nip, i.e., the nip between the upper roll and the middle roll, the fabric web is then supplied for the changed treatment to the lower nip, i.e., the nip between the lower roll and the middle roll. The nip which is not in use remains open. A calender of the above-described type has been found acceptable in principle for different treatment possibilities of fabric webs. However, the change of one type of treatment in one nip to another type of treatment in the other nip is relatively cumbersome. In particular, the path along which the fabric web is guided must be changed. This is true for the entry side as well as the exit side. If the fabric web is a non-woven fabric which is to be bonded in the nip, for example, a supply belt on which the fabric is supplied to the nip must be pivoted. The fabric web must either travel with a different travel path through cooling rolls which as a rule are arranged at the exit of the nip, or the position of the cooling rolls must also be changed.
A calender of the above-described type is also known from DE 37 12 276 C1. In one embodiment of this calender, three rolls are arranged one above the other, wherein the middle roll can be moved either upwardly to form a nip with the upper roll, or downwardly to form a nip with the lower roll. The fabric web is supplied through a pivotable supply unit whose supply path ends either a short distance below the upper roll or a short distance above the lower roll. The fabric web leaving the respective nip is guided either from below or from above around a guide roll and leaves the calender in a slightly upwardly or downwardly inclined direction.
SUMMARY OF THE INVENTION
It is the primary object of the present invention to facilitate the change from one type of operation to another type of operation.
In accordance with the present invention, in a calender of the above-described type, the first roll is movable between a first work position in which it forms the nip with the third roll and a first parking position, and the second roll is movable between a work position in which it forms the nip with the third roll and a second parking position, wherein the two work positions coincide and the parking positions of each of the first and second rolls is distanced from the third roll by such a distance that a movement of the respectively other roll between the work position and the parking position is possible.
The statement that the two work positions coincide does not mean that they coincide in the mathematical sense. Smaller deviations are permissible as long as the nip, which is formed by the respective first or second roll which is in the work position with the third roll, produces essentially the same treatment result, independently of which roll is at a given time in the work position. Of course, this is only true if the first and second rolls are equal. However, the first and second roll will normally be of different construction. The differences may be in the surface structure or in the material if the first or second rolls or both rolls are constructed as engraved rolls. The differences may also be in the temperature or in other physical properties. A change in the type of operation from a treatment in the nip between the first and second rolls to a treatment in the nip between the second and third rolls is relatively simple. In particular, it is not necessary to change the entry travel path or the exit travel path of the fabric web. It is merely necessary to move the roll which prior to the change of the type of operation was in the work position into its parking position and to move the other roll from its parking position into the work position. Such movements can be carried out substantially simpler than the change of a travel path. It is merely a prerequisite that the roll in the parking position leaves room for the movement of the other roll from the work position into the parking position and vice versa.
In accordance with a preferred embodiment, the first roll and the second roll are each movable together with their drive and possibly supply units. Accordingly, each roll when moved takes along with it its drive and possibly its supply unit, for example, required for achieving a predetermined temperature. Accordingly, when changing from one type of operation with the first roll to another type of operation with the second roll, it is actually only necessary to move the respective roll. It is not necessary to provide new connections or to connect drives to the respective roll. The roll which is in the parking position can continue to rotate with a rate of rotation independent of the production speed, for example, for cooling the roll.
In accordance with a preferred embodiment, the first roll is mounted on the frame through a first pivoting lever and the second roll is mounted on the frame through a second pivoting lever, wherein each pivoting lever is pivotable about a pivot axis. The movement of the rolls can be carried out quickly and without problems with a pivoting movement. During the pivoting movement, the pivoting lever is secured to the pivot axis. Consequently, the pivot lever always has a defined position relative to the frame, so that the control of the movement is very simple.
Each pivoting lever can preferably be secured relative to the frame on the side of a press plane located opposite the pivot axis, wherein the press plane extends through the two roll axes of the rolls forming the nip. This takes into consideration that for treating the fabric web the third roll is pressed with a certain force against the roll located in the work position. The first or second roll located in the work position is secured through the pivot axis to the frame. However, without the additional attachment of the pivoting lever, a relatively large moment would act on the pivoting lever, wherein the moment is difficult to absorb. By attaching the pivoting lever to the frame on both sides of the press plane, this problem is eliminated. The attachment can also be carried out indirectly at least on one side.
In accordance with a preferred feature, the pivoting lever located in the work position can be locked to the pivoting lever in the parking position. This does not result in an indirect locking of the pivoting lever in the working position to the housing. Rather, the pivoting lever is locked directly through the respectively other pivo
Calvert John J.
Kleinewerfers Textilmaschinen GmbH
Kueffner Friedrich
Welch Gary L.
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