Abstract:
An offline tubular blanket washing system includes a tube washer for cleaning blanket tubes removed from a printing unit. A storage rack receives the blanket tubes cleaned in the tube washer and stores the blanket tubes for installation in the printing unit.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to a tubular blanket washing system which is offline, i.e. not part of a printing press. 
     Offset lithographic web printing presses have printing units containing several printing cylinders rotating between side frames. The cylinders include a print cylinder carrying a print form having an image thereon and a blanket cylinder carrying a blanket tube. The image is transferred from the print form to the blanket tube and from the blanket tube to the web. 
     Vertical and horizontal web offset presses having gapless blanket tubes may include on-press blanket washers. Such washers are typically integrated into the structure of the press. However, end users of web offset presses often do not purchase on-press blanket washers and therefore manual washing of the blanket tubes must be performed. This results in down-time for the press and accordingly must be performed quickly leaving little time for inspection. The tubes do not have time to “rest” and be rejuvenated and the use of chemicals on the press is required. 
     In addition, some presses have limited access for washing the blanket tubes and some washing chemicals are not recommended for use on the press. In such cases, the blanket tubes must be removed for cleaning. U.S. Pat. No. 5,813,336 discloses a printing unit from which print forms and blanket tubes can be removed through an opening in a side frame. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the invention to provide an offline tubular blanket washing system, which overcomes the herein afore-mentioned disadvantages of the heretofore-known devices of this general type, which reduces down-time while permitting the surface of the blanket tube to be cleaned quickly and inspected for quality and performance, which is less labor-intensive, permits the tubes to rest and be rejuvenated between production runs, controls the use of chemicals and efficiently stores unused blanket tubes. 
     With the foregoing and other objects in view there is provided, in accordance with the invention, an offline tubular blanket washing system, comprising a tube washer for cleaning blanket tubes removed from a printing unit; and a storage rack for receiving the blanket tubes cleaned in the tube washer and storing the blanket tubes for installation in the printing unit. The tube washer may be disposed on the storage rack. 
     Through the use of this device, two sets of blanket tubes can be used, one on and one off the press. The tubes are washed by the tube washing off the press instead of by personnel manning the press. Compounds and conditioners for rejuvenating the surface of the blanket tube my be employed. Cleaned blanket tubes are always ready in the storage rack to be installed in the printing units. 
     In accordance with another feature of the invention, the tube washer includes side frames for rotatably supporting one or two blanket tubes, a driven rotating brush rotatably supported in the side frames for cleaning the blanket tubes, and one or two cleaning solution applicators associated with the blanket tubes and the rotating brush. 
     In accordance with a further feature of the invention, the tube washer includes a waste collector disposed below the blanket tubes and the rotating brush for receiving the cleaning solution. The tube washer may also have a filter and treatment device for receiving the cleaning solution and selectively guiding the cleaning solution back to the cleaning solution applicators. 
     In accordance with an added feature of the invention, the blanket tubes are installed in and removed from the tube washer through one of the side frames. 
     In accordance with an additional feature of the invention, the storage rack has two side walls defining a slot therebetween for receiving the blanket tubes from the tube washer and dispensing the blanket tubes for installation in the printing unit. 
     In accordance with yet another feature of the invention, according to one embodiment, the slot is L-shaped, and the storage rack has a blanket tube pick up and return region associated with the slot. According to another embodiment, the slot is inverted U-shaped, and the storage rack has a blanket tube pickup region and a blanket tube return region associated with the slot. The storage rack may also be horizontally oriented. 
     In accordance with a concomitant feature of the invention, the storage rack has an environmental control device for the blanket tubes. 
     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 an offline tubular blanket washing system, 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. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic, perspective view of a two-directional blanket tube storage and conditioning system with a blanket tube washer shown in phantom; 
     FIG. 2 is a side-elevational view of a one-directional blanket tube storage and conditioning system with a blanket tube washer shown in outline form; 
     FIG. 3 is a partly broken-away, front-elevational view of a blanket tube with storage chucks and a fragmentary, side-elevational view of a printing unit using the blanket tube; 
     FIG. 4 is an enlarged, perspective view of the blanket tube washer; and 
     FIG. 5 is a side-elevational view of the blanket tube washer with side frames removed. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a two-directional blanket tube storage and conditioning system having a storage rack  1  for blanket tubes  2 . The storage rack  1  may be installed at the location of a printing press. The storage rack  1  has L-shaped walls  3 ,  4  defining a slot  5  through which the blanket tubes  2  can move. The slot  5  has a blanket tube pick up and return region  6 . A blanket tube washer  20  is shown in phantom in FIG. 1 to illustrate its position on the storage rack  1 , but will be described in greater detail below with regard to FIG.  4 . The blanket tubes  2  may be inserted into the slot  5  through the region  6  after washing and conditioning and may be removed through the region  6  for installation in a printing unit  11  shown in FIG.  2 . An environmental control device  9 , which is installed on the wall  4 , may be an air conditioning system blowing into the slot  5  for rejuvenating the blanket tubes  2  after cleaning in the blanket tube washer  20 . 
     FIG. 2 shows a one-directional blanket tube storage and conditioning system having a storage rack  10  for the blanket tubes  2 . The storage rack  10  is intended to be installed at a location other than at a printing press. The storage rack  10  has Ω-shaped or inverted U-shaped walls  13 ,  14  defining a slot  15  for the blanket tubes  2 . The slot has a clean blanket tube pickup region  16  and a clean blanket tube return region  17 . The blanket tube washer  20  is shown in outline form on the storage rack  10 . The environmental control device  9  is also installed on the storage rack  10 . 
     FIG. 3 is a front-elevational view of a blanket tube  2  removed from the printing unit  11 . The blanket tube  2  has storage chucks  7  and a gapless blanket  8 . 
     FIG. 4 shows details of the tube washer  20 . The tube washer  20  has a drive-side frame  21  containing AC or pneumatic motors  25  and an operator-side frame  22 . Two blanket tubes  2  are journaled between the side frames  21 ,  22  and are driven by two of the motors  25  so as to rotate on the chucks  7 . The blanket tubes  2  to be cleaned and conditioned are installed in and removed from the tube washer  20  in the direction of arrows  23  through the side frame  22 . The installation and removal is accomplished as described in U.S. Pat. No. 5,813,336. A rotating brush  24  is also journaled between the side frames  21 ,  22  and is driven by one of the motors  25 . Naturally, one motor may be used with appropriate gearing, instead of three. The brush  24  may be moved vertically as indicated by a doubled-headed arrow, into and out of contact with the blanket tubes  2 . Two cleaning solution applicators  26  are each disposed above a respective one of the blanket tubes  2 . Finally, a waste collector  27  is disposed between the side frames  21 ,  22  and below the blanket tubes  2  and rotating brush  24  for collecting cleaning solution dropping from the blanket tubes. 
     FIG. 5 shows the cleaning solution applicators  26 , the blanket tubes  2  and the rotating brush  24  installed in the tube washer  20  above the waste collector  27 . As is illustrated by arrows in FIG. 5, the brush  24  reciprocates in circumferential direction and the blanket tubes  2  rotate toward each other. The cleaning solution is applied by the applicators  26  so as to clean and recondition the blanket tubes  2 . Waste solution dropping into the collector  27  is removed through a tube  28  leading to a filter and treatment device  29  for the waste solution. The treated solution may be returned to the applicators  26  through a tube  30  or removed through a tube  31  for further treatment. 
     The actual cleaning sequence takes place by rotating the blanket tubes  2  and then applying the washing fluid or cleaning solution. The brush  24  is then placed in contact with the blanket tubes and rotated against them. After a period of time, the rotation is stopped and the blanket tubes are removed from the tube washer  20 . 
     According to the invention, blanket tubes  2  are removed from a printing unit  11  and cleaned and conditioned in a tube washer  20  installed on a storage rack  1  or  10  according to FIG. 1 or FIG.  2 . The cleaned and conditioned tubes are placed into a pick up and return region  6  or a pickup region  16  of the storage rack  1  or  10 . The cleaned and conditioned tubes are then removed from the storage rack through the pick up and return region  6  or the return region  17  and placed into the printing unit  11  as needed. The storage rack may be located alongside the press of offsite. It is also noted that the storage rack may be horizontally configured, with the walls  3 ,  4  in a horizontal orientation and the region  6  facing upward.