Patent Application
20080121770
This application claims the priority, under 35 U.S.C. ยง 119, of Austrian application A 1944/2006, filed Nov. 23, 2006; the prior application is herewith incorporated by reference in its entirety.
The present invention relates to a device for detachably fixing a holder for a doctor blade, which is assigned to a supporting and guiding roll in a paper production plant, to a support. The holder is mounted on the support such that it can be pivoted about an axis oriented at least approximately in the direction of the doctor edge bearing on the supporting or guiding roll. Furthermore, the holder is formed by holding fingers which extend transversely with respect to the pivot axis and which are in each case constructed with a first bearing part which interacts with a second bearing part located on the support and, between the holder and the support, there is disposed at least one actuating element, by means of which the holding fingers can be pivoted independently of one another.
In paper production plants there is a wire, which is moved along the plant on supporting or guiding rolls and to which the paper stock or pulp is applied. In the direction of movement of the wire, the liquid contained in the paper stock is sucked out of the latter and the paper web produced as a result is dried by means of air sucked through the wire. In the further course of the movement path of the paper web in this plant there is a felt, on which the paper web is dried further. Both the wire and the felt are moved over supporting and guiding rolls. Further on, the paper web is moved directly over supporting and guiding rolls.
On account of the liquid sucked out of the paper stock and on account of the drying operations, constituent parts, in particular pulp fibers, led out of the paper stock or out of the paper web reach the supporting or guiding rolls, which means that the latter become contaminated. Since these contaminants impair the operation of the supporting or guiding rolls, there is the need to subject them to continuous cleaning. For this purpose, the supporting and guiding rolls are in each case assigned a doctor blade, which is brought into contact with the relevant supporting and guiding roll and by means of which contaminants located on the roll are doctored off the latter.
Here, there is the need to arrange the doctor blade in such a way that it bears on the relevant roll with a predefined pressure. For this purpose, the holder of the doctor blade is constructed with a device for adjusting the angular position of the doctor blade with respect to the relevant roll. Since, moreover, the holder of the doctor blade often has to be replaced in order to be able to clean the latter and the doctor blade, there is also the need to construct the fixing of the holder for the doctor blade to the support for the holder in such a way that it can be released in the simplest possible way.
In prior art devices of this type, the holder for the doctor blade and the support of the holder are constructed with lugs projecting toward one other, which are formed with drilled holes assigned to one another, into which a bearing pin extending over the width of the wire is inserted. In order to be able to remove the holder for the doctor blade from the support for the holder, the bearing pin is pulled out laterally. In this way, the holder for the doctor blade can be removed from the support, that is to say lifted off, transversely with respect to the longitudinal direction of the bearing pin. In this case, however, there is often the difficulty that, on account of the constructional configuration of the plant, the space required for a movement of the holder transversely with respect to its support is not available.
It is accordingly an object of the invention to provide a device for releasably fixing a holder for the doctor blade in a paper production plant which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is further developed in such a way that the holder for the doctor blade can be displaced with respect to the support in the longitudinal direction of the bearing pin without needing to be moved from the carrier, that is to say lifted off the latter, transversely with respect to the insertion direction.
With the foregoing and other objects in view there is provided, in accordance with the invention, an assembly for mounting a doctor blade assigned to a supporting and guiding roll in a paper production plant, comprising:
a support and a holder for carrying the doctor blade detachably mounted to the support and pivotally mounted on the support about a pivot n axis oriented substantially in a direction of a doctor blade edge bearing on the supporting or guiding roll;
the holder being formed by a plurality of holding fingers extending transversely with respect to the pivot axis and each having a first bearing part interacting with a second bearing part on the support;
at least one actuating element disposed between the holder and the support for pivoting the holding fingers independently of one another;
one of the first and second bearing parts being formed by a bearing shell having a cutout formed therein, extending in the direction of the pivot axis, and the other of the first and second bearing parts being formed by a bearing pin carried by a web penetrating the cutout in the bearing shell, enabling the holder to be displaceable with respect to the support in the direction of the pivot axis over an entire length of the doctor blade.
In other words, the objects of the invention are achieved in that one of the two bearing parts is formed by a bearing shell, which is formed with a cutout, in particular with a slot, extending in the direction of the pivot axis, and the other bearing part is formed by a bearing pin which is carried by a web or the like penetrating the cutout in the bearing shell, which means that the holder can be displaced with respect to the support in the direction of the pivot axis over the entire length of the doctor blade.
Preferably, each holding finger is formed with a separate bearing part, whereas the bearing part located on the support extends in one piece over the entire length of the doctor blade or is formed by individual sections of the bearing part located at a distance from one another. In particular, each holding finger is assigned a bearing pin, which is fixed to the holding finger by means of a web or the like, and on the support there is provided a strip-like bearing shell extending over the length of the doctor blade, or a plurality of sections of the strip-like bearing shell are provided, the at least one bearing shell being formed with cutouts, in particular with slots, on its side assigned to the holding fingers.
Preferably, a covering plate extending over all the holding fingers is also provided, is fixed to the holding fingers and bears on the edge of the doctor blade assigned to the holder. Furthermore, at their end assigned to the doctor blade, the holding fingers can be formed with profiling used for the fixing of the doctor blade. In particular, at their end assigned to the doctor blade, the holding fingers are each formed with a cutout, into which a strip projecting from the doctor blade can be inserted.
According to further preferred features, the holding fingers are formed as two-armed levers, which are mounted on the support in their central region, and the support for the holding fingers is constructed with a flexible covering element reaching over the holding fingers.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in device for the detachable fixing of a holder for a doctor blade in a paper production plant, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Referring now to the figures of the drawing in detail and first, particularly, to
The doctor blade 2 is fixed to a holder 3, which is formed by a large number of holding fingers 31 arranged beside one another and a covering plate 32 located above these. For this purpose, at its edge facing the holder 3, the doctor blade 2 is formed with a strip 21 which projects into cutouts 33 provided at the ends of the holding fingers 31. Furthermore, by means of the covering plate 32, which is screwed to the holding fingers 31, all the holding fingers 31 are connected to one another to form a single structural unit.
The holder 3 for the doctor blade 2 can be pivoted with respect to a support 5 for the holder 3 by means of a bearing 4 on the support 5. In order to adjust the pivoted position of the holder 3 with respect to the support 5, between the support 5 and the holder 3 there are two actuating elements in the form of inflatable hoses 6, by means of which the angular position of the holder 3 with respect to the support 5 can be adjusted.
In addition, at the ends of the holder 3 and of the support 5 that face away from the doctor blade 2, a flexible covering element 51 is provided.
The support 5 is located on a swinging arm 7, which is fixed to a shaft 8 which extends in the axial direction of the roll 1 and which can be adjusted into a pivoted position by means of a tensioning rod 9 and can be fixed in this position.
As can be seen further from
| Number | Date | Country | Kind |
|---|---|---|---|
| A 1944/2006 | Nov 2006 | AT | national |
