Patent Publication Number: US-7896329-B2

Title: Waste blower for a paper sheet punching and embossing machine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a paper sheet punching and embossing machine. 
     2. Description of the Related Art 
     In known sheet punching and embossing machines, which are used for punching, tearing off, embossing and delivery of sheets of paper, cardboard, and other stock materials, it is known how to move the sheets with gripper cars into the individual stations of the machine. Grippers are secured on the cars and grab the sheets at a front end, while the gripper cars are moved on endless chains through the machine. With this type of movement of the sheets through the machine, continuous operation in the individual stations of the machine arranged one after the other is obtained. Since an impression of the gripper on the final punched and/or embossed sheet is undesirable, the marginal region at which the gripper grabs the sheet is separated from the finished sheet. This gripping margin is usually discarded at the end of the machine. Many different devices are known for separating the gripping margin from the sheet. 
     EP 0 586 876 B1 discloses a known a device in which a revolving cutting cylinder includes spaced apart blades, and a suction and blowing mechanism is arranged between the spaced blades. After the waste strip is separated by the blades arranged on the cylinder, the waste strip is held by a partial vacuum against the cylinder and transported away. The actual discarding of the waste strip occurs when, first, the suction is replaced by a blowing, and second, an exhaust hood is arranged above the cylinder, so that the waste strip is blown away from the cylinder by the blown air and attracted by the suction air of the exhaust hood. 
     DE 102 59 556 A1 discloses a known sheet punching and embossing machine of this kind, in which gripper cars are secured to revolving chains, and sheets are pulled through a sheet punching and embossing machine by grippers. The sheet punching and embossing machine includes a punching mechanism, a tear-off mechanism and a delivery mechanism. In a discarding station connected downstream, a gripping margin separated from the sheet is discarded. Discarding occurs by opening the grippers of the car, such that the gripping margin is dropped. To facilitate discarding of the gripping margin, brushes or wiper fingers are provided in the machine frame between the grippers. 
     Depending on the type of sheet being processed in the machine, a larger or smaller gripping margin will be wasted. A gripping margin is typically between two centimeters and five centimeters. Additionally, the gripping margin may also consist of a full-size sheet, from which the copy has been punched out. This gripping margin including a margin several centimeters thick, having the size of the complete sheet, also must be transported to the delivery station. 
     Especially when the gripping margin corresponds to a full-size sheet, the grip opening cam at the discarding station has to be adjusted to the gripping margin in order to eliminate the gripping margin as waste from the machine. For this, the machine must be retrofitted. With a normal gripping margin, one grip opening cam is attached in a first position and with a gripping margin equal to the size of the sheet a second grip opening cam is attached in a second position. For this, the ejection point has to be adjusted in a stepless manner, depending on the machine speed and the paper weight. Especially in the case of a gripping margin equal to the size of the sheet, this results in retrofitting costs, on the one hand, and a reduction in the machine speed, on the other, in order to eject a gripping margin equal to the size of the sheet from the machine. 
     SUMMARY OF THE INVENTION 
     To overcome the problems described above, preferred embodiments of the present invention provide a sheet punching and embossing machine in which a costly retrofitting of the machine is avoided, reliable ejection of different gripping margins is accomplished at maximum machine performance and with low cost and simple structural elements. 
     According to preferred embodiments of the present invention, a blower blows air towards an ejection station so that a directed current of air acts on the gripping margin. According to preferred embodiments of the present invention, a sheet punching and embossing machine achieves reliable ejecting of the gripping margin without any retrofitting of the grip opening cam. Thus, ejection of the gripping margin is achieved at low cost. 
     In a preferred embodiment of the present invention, several blowers are secured next to one another across the entire width of the ejection station, so that a blower strip is defined. This ensures that gripping margins of different sizes can be reliably ejected over the entire width of the ejection station. 
     Preferably, a conveyor belt is provided in the ejection station below the movement trajectory of the gripper car. This facilitates the ejection of especially large gripping margins. 
     In another preferred embodiment of the present invention, the blower is secured inside the circular path of the gripper car in the machine frame. This ensures that the current of air can be accurately directed towards the conveyor belt. 
     In another preferred embodiment, a suction blower is secured outside the circular path of the gripper car in the machine frame. With the suction blower, the gripping margin is reliably sucked out of the gripper car. 
     The use of a blower as a blowing and/or sucking blower produces a defined ejecting of the gripping margin because during the ejection of a long gripping margin, the air is transformed by the blower (either sucking or blowing) into a directed current of air. This enables a secure delivery of the gripping margin on a waste belt disposed beneath the path of the gripper car. 
     Other features, elements, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is the basic layout of a sheet punching and embossing machine. 
         FIG. 2  is a detailed side view in the region of an ejection station including a blowing blower. 
         FIG. 3  is a detailed side view in the region of an ejection station with a sucking blower. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  shows the basic layout of a sheet punching and embossing machine  1  for punching, tearing off, embossing and delivery of sheets of paper, cardboard, or other stock materials. The punching and embossing machine  1  includes a punching mechanism  2 , a tear-off mechanism  3 , a delivery mechanism  4  and an ejection station  24 , which are supported and enclosed in a common machine housing  5 . 
     The sheets  6  are gripped in a gripping margin at their front edge by gripper rods  8  attached to revolving chains  7  and transported intermittently through the various stations  2 ,  3 ,  4  and  24  of the punching and embossing machine  1 . 
     The punching station  2  includes a lower table  9  and an upper table  10 . The lower table  9  is securely mounted in the machine frame and provided with a counterplate for the punching blade. The upper table  10  is mounted so as to be movable vertically up and down. 
     The gripper rod  8  transports the sheet  6  from the punching and embossing station  2  into the tear-off station  3 , which includes tear-off tools. In the tear-off station  3 , the unneeded scraps from the sheet  6  are torn off by the tear-off tools in a downward direction, so that the scraps  11  fall into a container cart  12  disposed under the station. 
     From the tear-off station  3 , the sheet is transported to the delivery station  4 , where either the sheet is merely stacked or where separation of individual copies is performed at the same time. The delivery station  4  may also include a pallet  13  on which the individual sheets are stacked in the form of a pile  14 , so that after a particular stacking height is reached, the pallets with the sheets stacked thereon can be transported away from the punching and embossing machine  1 . 
     As shown in  FIG. 1 , the chains  7  include several gripper cars  8 , so that several sheets  6  can be processed in the various stations  2 ,  3 ,  4  and  24  at the same time. 
     At the delivery mechanism  4 , the gripping margin (not shown) is separated from the sheet  6 . At the ejection station  24 , the separated gripping margin  15  is ejected and hauled away by a conveyor belt  17 . The ejecting is usually performed by opening of the gripper  8  or by a combined opening of the gripper  8  and a brush  21  (see  FIG. 2 ) arranged next to the grippers  8 , which eject the gripping margin  15  from the gripper car in the event that the gripping margin  15  remains stuck in the gripper car  8  when the gripper  8  is open. 
       FIG. 2  shows a side view of a sheet punching and embossing machine according to a preferred embodiment of the present invention in the region of the ejection station  24  at which the gripping margin  15  is discarded. As noted above, the dimensions of the gripping margin may correspond to those of the entire sheet.  FIG. 2  shows a conveyor belt  17 , which is secured in the machine frame  20  underneath a circular path  18  of the gripper car  19 . The portion of the sheet punching and embossing machine defining the circular path  18  for the gripper car  19  is a portion of the machine frame  20 . Approximately in the middle of the circular path  18 , a wiping brush  21  is mounted in the machine frame  20 . Inside the circular path  18 , a blower  22  is secured in the machine frame  20 . In order to intensify the directed current of air, a baffle  23  is disposed beneath the wiping brush  21 . In addition to the benefit of a direction air flow, the baffle  23  ensures a directed ejection of the gripping margin  15 . 
     In a preferred embodiment of the present invention, the blower or blowers  22  are secured in the machine frame  20  and are distributed uniformly across the entire width of the machine, at substantially regular intervals from each other. For example, five blowers  22  may be secured in the machine frame  20  and distributed next to each other across the width of the machine. The blowers are preferably speed-regulated, and the speed is regulated as a function of the gripping margin and the paper weight. In addition, the machine speed is factored into the automatic control process. Thus, the current of air and thus the force exerted on the waste paper is continuously regulated as a function of the machine speed. By providing a blower strip  22 , a constant force is produced in the direction of the waste paper belt  17 . This has the effect of enabling the machine speed to be increased by 20% without retrofitting the grip opening cams. Furthermore, it is beneficial for design considerations that the blower strip may be installed in a sheet of metal of the ejection station, also known as the delivery. 
     In the direction of the arrow P, the gripping margin  15  is transported to the indicated delivery  24 , where the gripper  25  of the gripper car  19  opens and thus releases the gripping margin  15 . Due to the directed air flow, indicated here by the arrows  26 , the ejecting of the gripping margin  15  is facilitated. Due to the blower strip  22 , a constant force is produced in the direction of the waste belt  17 . This enables even long gripping margins to be disposed on the conveyor belt  17  with no problems and delivered out of the sheet punching and embossing machine. The conveyor belt  17  moves the ejected gripping margins  15  in the direction of the arrow F from the machine. Another benefit resulting from a blowing blower  22  or a blower strip  22  is that the waste stream can be more easily guided with relatively small distances between the wastes. 
     According to preferred embodiments of the present invention, it is possible to use a sucking blower  27 , in addition to a blowing blower  22 , as shown in  FIG. 3 . The gripping margin  15  is not forced out from the gripper car  19  by the blower  22 , but instead is pulled out from the grippers  25  of the car  19  by the directed air flow  28  of the blower  27 . This provides a benefit if, for example, existing machinery needs to be modified or retrofitted with a blower strip  27 . Since the blower strip  27  is mounted behind the circular path  18  of the gripper car  19 , and the blower strip  27  can be easily installed. 
     It is noted that a sucking blower  27  and a blowing blower  22  may be used together and at the same time, depending on the weight of the sheet being handled. 
     While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.