Abstract:
Arrangement and method for handling doctor blades of a paper/board machine which are placed against a face of a roll in the paper/board machine to keep the face clean and to service the face. A doctor blade blank is formed from a doctor blade roll, i.e., from a reel of doctor blade material, by unwinding the roll of doctor blade material and cutting the doctor blade material at a determined cut-off point to thereby obtain a doctor blade blank having a desired pullout or blade length and which will be modified to form a doctor blade.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    The present application is a divisional application of copending U.S. patent application Ser. No. 09/263,397 filed Mar. 5, 1999 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present relates to an arrangement and method for forming doctor blade blanks for use for a roll in a paper/board machine. The present invention relates to an arrangement and method for handling doctor blades for a roll in a paper/board machine.  
         BACKGROUND OF THE INVENTION  
         [0003]    In the prior art, the use of various doctor blades in a paper or board machine is known. A doctor blade is an important part of a paper or board machine which secures the operation of the paper/board machine, i.e., ensures its operability. The blade is typically arranged in connection with a roll and maintains the condition of the roll face and removes a web portion from the roll face which is then passed out of connection with the roll into a pulper.  
           [0004]    As is well known in the art, doctor blades have been stored in connection with the paper/board machine on various shelves for doctor blades. For use, the doctor blade is lifted from the shelf straight into a doctor blade holder construction.  
         OBJECTS AND SUMMARY OF THE INVENTION  
         [0005]    It is an object of the present invention to provide a new and improved arrangement and method for handling doctor blades.  
           [0006]    It is another object of the present invention to provide a new and improved arrangement and method for the storage and preparation of doctor blades for a paper/board machine.  
           [0007]    It is another object of the present invention to provide new and improved arrangements and methods for forming doctor blade blanks for subsequent use as doctor blades.  
           [0008]    In order to achieve these objects, and others, in accordance with the invention, a separate storage carriage is employed, which comprises at least one roll of doctor blades from which the doctor blade can be unwound, i.e., a reel of doctor blade material. The doctor blade material placed on the roll can be unwound through a separate measurement device and associated cut-off device. The cut-off device comprises a measurement detector from which the pulled-out length of the doctor blade and the residual length remaining in the roll can be measured and read. At a desired point, the feed of the doctor blade from the roll is stopped, and the doctor blade is cut off to the desired length. The roll of doctor blades is arranged around a revolvingly mounted shaft and the band of doctor blades is passed through separate guides to the cut-off device. A measurement detector of the measurement device is placed in direct vicinity of the cut-off device and measures the blade length that has been fed. From a display placed in connection with a central processing unit, it is possible to read the blade length that has been fed out, and further, from the display it is possible to read the blade length that remains on the roll of doctor blades.  
           [0009]    The roll of doctor blades is placed in a separate carriage, which can be shifted into different locations in connection with the paper/board machine. Thus, the same carriage can be used in different locations while the carriage comprises a number of different rolls of doctor blades and separate cut-off means and measurement detectors for the rolls of doctor blades.  
           [0010]    Thus, in one embodiment of an arrangement for forming doctor blade blanks from at least one roll of doctor blade material, holding means, e.g., a storage carriage, is provided to hold each roll of doctor blade material such that the doctor blade material is unwindable therefrom and cutting means for cutting each roll of doctor blade material after the doctor blade material has been at least partially unwound from the roll to form a doctor blade blank having a desired length. Preferably, the length of the doctor blade material being unwound from each roll is measured by measurement means, e.g., a measurement detector arranged in connection with each roll. The central processing unit is coupled to the measurement means, e.g., by a data transfer bus, for receiving the measured length of the doctor blade material being unwound from each roll and is arranged to enable the cutting means to be manually or automatically actuated to cut the desired length of doctor blade material from each roll. To this end, a display is coupled to the central processing unit, e.g., by a data transfer bus, for displaying the measured length of the doctor blade material being unwound from each of the at least one roll.  
           [0011]    The carriage may include one or more compartments, each roll being situated in a respective compartment, and an opening associated with each compartment through which the doctor blade material from the roll situated in that compartment is unwound. The measurement means, e.g., a measurement detector arranged in each compartment at or proximate the opening, thereby measures the length of doctor blade material being unwound from the roll situated in the compartment and passed through the opening. The cutting means, e.g., a cut-off device, are also arranged proximate the opening of each compartment and guide means are associated with each compartment for guiding unwinding of the doctor blade material through the opening.  
           [0012]    In the method for forming doctor blade blanks from at least one roll of doctor blade material, the doctor blade material is unwound from the roll(s), the length of the doctor blade material being unwound is measured, a cut-off point on each roll of doctor blade material is determined in order to obtain a doctor blade blank having a desired length, the unwinding of the doctor blade material is stopped once the doctor blade material has been unwound past the cut-off point, and then the doctor blade material is cut at the cut-off point to thereby form a doctor blade blank having the desired length. This procedure is repeated when necessary to enable the formation of multiple doctor blade blanks from a single roll of doctor blade material.  
           [0013]    In the following, the invention will be described in detail with reference to some exemplifying embodiments of the invention illustrated in the figures in the accompanying drawing. However, the invention is by no means strictly confined to the details of the illustrated embodiments alone. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.  
         [0015]    [0015]FIG. 1 is a perspective view of a storage carriage for rolls of doctor blades in accordance with the invention.  
         [0016]    [0016]FIG. 2 is a schematic illustration of a roll of doctor blades in accordance with the invention.  
         [0017]    [0017]FIG. 3 is a schematic illustration of the operation of an arrangement in accordance with the invention as a block diagram presentation. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    Referring to the accompanying drawings wherein the same reference numerals refer to the same or similar elements, FIG. 1 is a perspective view of a storage carriage for rolls of doctor blades including separate compartments (also referred to as stations or positions) for different reels or rolls of doctor blades as well as, for each reel or roll, separate cut-off devices for cutting the reels or rolls to form doctor blades and measurement detectors for measuring the length of the doctor blade. The doctor blades formed from the roll or reel of doctor blade material can also be called doctor blade blanks, because a length of doctor blade material that has been cut off to the specified measure is usually provided with perforations and required fastenings and only then would constitute a doctor blade useable in a paper/board machine. Once provided with perforations and fastenings, the doctor blade is installed in connection with a roll in the paper/board machine.  
         [0019]    More specifically, FIG. 1 shows a storage carriage  50  for rolls of doctor blades  10   a   1 ,  10   a   2 ,  10   a   3  which comprises a box-like frame R, an upper, openable lid R 1  and a side cover R 2 . Wheels  50   a   1 , 50   a   2 , 50   a   3 , 50   a   4  (of which only  50   a   4  is not shown) are provided on a lower surface of the frame R to enable the carriage  50  to be moved to different locations in the paper/board machine. The rolls of doctor blades  10   a   1 ,  10   a   2  and  10   a   3  are placed in compartments D 1 , D 2  and D 3 , respectively, inside the frame R. Although three compartments are shown, it should be understood that the frame R may contain any number of compartments. Each roll of doctor blades  10   a   1 ,  10   a   2 ,  10   a   3  is rotatably mounted on a shaft  11  which is revolvingly mounted on bearings  12   a   1 ,  12   a   2 . Measurement device  13  includes a measurement detector  13   a   1  arranged in connection with the feed-out opening A 1  of the compartment D 1  of the doctor blade roll  10   a   1  for measuring the length of a doctor blade T to be formed. Cut-off device  14   a   1  and at least one guide  15   a   1 ,  15   a   1 ′, . . . (shown in FIGS. 2 and 3) are also arranged in connection with the feed-out opening A 1 . Based on a measurement signal produced by means of the measurement detector  13   a   1 , the feed-out length of the doctor blade T that has been fed out and also the residual length remaining on the roll  10   a   1 , are computed in a central processing unit  100 , and the measurement data can be read from a display  16  connected to the central processing unit. When the desired/estimated feed-out length of the doctor blade T has been reached, unwinding of the doctor blade material is stopped and the cut-off device  14  is operated and the doctor blade T is cut off. In a corresponding manner, compartments D 2  and D 3  comprise similar arrangements for the doctor blade rolls  10   a   2 ,  10   a   3 , respectively, associated with the compartments. The feed-out length of the doctor blade T can also be estimated, in which case a measurement device is not required.  
         [0020]    [0020]FIG. 2 is a schematic illustration of a roll of doctor blades, i.e., a reel of doctor blades  10   a   1 ,  10   a   2 ,  10   a   3 , in accordance with the invention, wherein each roll or blank of a doctor blade is mounted on a shaft, which is provided with bearings. In the vicinity of the feed-out end of each doctor blade, there is the measurement detector and cut-off device. In the vicinity of each feed-out opening, there is also the guide for the doctor blade.  
         [0021]    More specifically, FIG. 2 shows doctor blade roll compartments D 1 , D 2 , D 3 , each including a shaft  11   a   1 ,  11   a   2 ,  11   a   3  for a roll of doctor blades  10   a   1 ,  10   a   2 ,  10   a   3 , bearings  12   a   1 ,  12   a   2  mounted on the shaft  11   a   1 ,  11   a   2 ,  11   a   3 , a feed-out opening A 1 , A 2 , A 3  and a measurement detectors  13   a   1 ,  13   a   2 ,  13   a   3  arranged in connection with the feed-out opening A 1 ,A 2 ,A 3 . Display  16  is arranged to display the measurement information produced from each compartment D 1 , D 2 , D 3 . The central processing unit  100  interposed between the measurement device  13  and the display  16  operates as a collector/processor of the data from the measurement device  13 , i.e., from the measurement detectors  13   a,  and directs the measurement data along a bus e 4  to the display  16 . The measurement data is obtained based on the information produced by the measurement detectors  13   a   1 ,  13   a   2 ,  13   a   3 . The cut-off device  14   a   1 ,  14   a   2  and  14   a   3  of each station D 1 , D 2 , D 3  performs the cutting-off of the doctor blade T based on the data read from the display  16 . The cutting-off can be carried out by the operator of the carriage  50 . In addition to the cut-off device, the arrangement in accordance with the invention can also include a perforation device  200 , by whose means pull-out holes can be perforated to the end/ends of the doctor blade (FIG. 2). The perforation device  200  may be arranged in connection with the cut-off devices  14   a,  or it may be a separate device which is independent from the cut-off devices  14   a  and which is displaceable to the desired compartment D 1 , D 2 , D 3 .  
         [0022]    Further, the central processing unit  100  optionally include controls for the operation of the cut-off devices  14   a   1 ,  14   a   2 ,  14   a   3 , i.e., the cut-off devices  14   a  are coupled to the central processing unit, e.g., by electrical cables. Such controls may be arranged, for example in connection with the lid R 1  of the carriage  50 . Similarly, the display  16  can be placed in connection with the lid R 1 .  
         [0023]    [0023]FIG. 3 is a block diagram of the operation of the arrangement in accordance with the invention which is used in a method in accordance with the invention. From the measurement detectors  13   a   1 ,  13   a   2  or  13   a   3  of the compartments D 1 , D 2 , D 3 , the measurement information is passed along data transfer buses e 1 , e 2 , e 3  to the central processing unit  100 , and further from the central processing unit  100  there is a data transfer bus e 4  to the display  16  for reading of the information of the compartments D 1 , D 2  and/or D 3 . Optionally, it is possible to read the length of the blade T that has been pulled out of the opening A 1 , A 2  and/or A 3 , in which case, the cut-off device  14   a   1 ,  14   a   2  and/or  14   a   3  can be operated when the desired pull-out length has been reached. From the display  16 , it is also possible to read, in respect of each compartment D 1 , D 2 , D 3 , the remaining blade length of the doctor blade roll  10   a   1 , or  10   a   2  or  10   a   3  placed in the respective compartment. The guides  15   a   1 ,  15   a   1 ′, . . . ,  15   a   2 ,  15   a   2 ′, . . . ,  15   a   3 ,  15   a   3 ′, . . . controls the path of the blade T in a controlled manner past the measurement detector  13   a   1 ,  13   a   2 ,  13   a   3  of each compartment D 1 , D 2 , D 3  and further past the cut-off device  14   a   1 ,  14   a   2 ,  14   a   3  related to the compartment D 1 , D 2 , D 3 .  
         [0024]    The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.