Abstract:
The invention provides a rotary punch assembly for punching successive sheets of paper, the assembly comprising a first punch pin roller and a second roller which form a nip therebetween. The first punch pin roller has a plurality of punch pins protruding therefrom and is driven, while the second roller has a resilient surface and is freely rotating. As a sheet is passed through the nip between the rollers, the punch pins penetrate the paper as the pins work against the resilient surface of the second roller to pierce the holes.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application is a continuation of International Patent Application No. PCT/US03/13983, filed May 5, 2003, which claims priority to U.S. Provisional Patent Application No. 60/378,334, filed May 6, 2002. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates generally to automated punching machines for perforating one or more sheets. More particularly, the invention relates to rotary punches typically utilized in in-line processing.  
       BACKGROUND OF THE INVENTION  
       [0003]     In the paper finishing industry, automatic die punching machines are utilized to punch regular, repeating patterns of holes through individual sheets or stacks of sheets in preparation for binding. Typical die punching machines utilize either reciprocating die punches which are actuated by a ram, or rotary die punches. In rotary die punches, one or more sheets are passed between a punch pin roller from which a plurality of punch pins protrude and a die roller having precision openings for receiving the punch pins. Such traditional rotary punches have complex gearing structures because the pins and the dies must precisely mate. As a result, changing or trading-out the pins or dies is generally an expensive and involved undertaking, typically resulting in a considerable amount of down time for the punch.  
       OBJECTS AND SUMMARY OF THE INVENTION  
       [0004]     It is a primary object to provide a rotary punch that is reliable, and economical to produce and operate.  
         [0005]     Another object of the invention is to provide a simplified rotary punch that includes a minimal number of moving parts and that is less complex than those currently available in the market.  
         [0006]     A further object is to provide a rotary punch that is compact in design.  
         [0007]     An additional object is to provide a rotary punch arrangement that has reduced service costs and wherein the individual components may be relatively easily and quickly changed out.  
         [0008]     In accordance with these and other objects of the invention, there is provided a rotary punch which includes a driven cylindrical punch pin roller and a freely rotating base roller which includes a relatively soft, resilient surface. As a sheet of paper is passed between the driven punch pin roller and the freely rotating resilient base roller, the punch pins penetrate the paper as the pins work against the resilient surface of the base roller to pierce holes into the paper.  
         [0009]     Thus, the inventive punch design utilizing a single driven roller and a freely rotating second roller provides a much simplified design over the current rotary punches which typically include very complex gearing arrangements in order to accurately drive the lower die roller in time with the upper punch pin roller. As a result, the complexity and associated cost of servicing the inventive new punch will also be greatly reduced over conventional designs. This reduced complexity is particularly apparent in the elimination of the complex gearing arrangements required in traditional rotary punches to accurately drive and synchronize the lower die roller for proper engagement with the upper punch pin roller. Consequently, the components of the inventive punch arrangement may be singularly quickly replaced or modified, i.e., the lower roller, the punch pin roller, or the punch pins themselves may be readily changed out. In sharp contrast, a traditional punch pin roller or die roller would require the complete punch assembly to be removed and disassembled in order to change out any single component. The rapid changeover of the inventive new punch design also allows for quickly changing the punch design itself, i.e., the hole arrangement, shape, number, and size.  
         [0010]     These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of a rotary punch arrangement constructed in accordance with teachings of the invention.  
         [0012]      FIG. 2  is a perspective view of a further embodiment of a rotary punch arrangement constructed in accordance with teachings of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]     Turning now to the drawing, there is shown in  FIG. 1 a  rotary punch arrangement constructed in accordance with teachings of the invention. The rotary punch assembly  10  includes a cylindrical punch pin roller or pin holder  12  from which a plurality of punch pins  14  extend. Although shown in a round configuration, the punch pins  14  may be of substantially any shape, size, number, and distribution along the roller  12 . Further, while a single row of punch pins  14  is illustrated such that a single row of perforations is made in a single sheet during each rotation of the punch pin roller  12 , it is understood that multiple rows of punch pins  14  may alternately be provided.  
         [0014]     The punch pin roller  12  is secured to a shaft  16  that is journalled for rotation in bearing supports  18 . Although the bearing supports  18  are supported in a pair of roller supports  20  secured to a base  22  or other frame, it will be appreciated by those of skill in the art that the rotary punch assembly  10  will be assembled into or secured to a punch machine or an in-line printer or the like to punch a series of sheets progressing down a line. While not shown, it will further be appreciated that the sheets to be punched may be fed to the rotary punch assembly by any appropriate means, such as, for example, a plurality of rollers and/or belts or the like. Examples of such punch stations or machines in which the inventive punch would be suitable are disclosed in U.S. Pat. No. 4,574,669 and PCT Application PCT/US0304962.  
         [0015]     In order to both support sheets as they pass through the rotary punch assembly and to facilitate punching the perforations through the sheets, a base or lower roller  24  is provided. In accordance with the invention, the lower roller  24  includes a resilient surface  26  such that as a sheet progresses through the nip  28  formed between the punch pin roller  12  and the lower roller  24 , the punch pins  14  press against the sheet and the resilient surface  26  of the lower roller  24 . The punch pins  14  will penetrate the sheet as the punch pins  14  depress the sheet against the resilient surface  26 .  
         [0016]     The currently preferred embodiment of the invention includes a rubber lower roller  24 . It has been determined that rubber provides sufficient depressibility and resiliency to result in clean cuts through sheets passed through the nip  28 , while providing a relatively durable lower roller  24 . Other resilient materials may likewise be utilized in the lower roller  24 . Moreover, the lower roller  24  may be formed essentially entirely of a resilient material such as rubber, or the roller may be formed of steel or the like and have a surface covering of a resilient material, such as rubber.  
         [0017]     In accordance with an important aspect of the invention, preferably only the punch pin roller  12  is driven, while the lower roller  24  is freely rotating, that is, not driven. It will be appreciated that the roller may have some resistance to rotation as a result of, for example, friction resulting from the mounting arrangement. No complex gearing arrangements, however, are required in order to synchronize the rotation of the two rollers  12 ,  24 . More importantly, however, the elimination of complex gearing arrangements utilized in synchronized rotary punch arrangements, facilitates greatly simplified and more rapid maintenance and changeover of the rotary punch  10 . Additionally, the rollers  12 ,  14  themselves are of a relatively lower cost than traditional rotary punch arrangements. As a result, punch pin rollers  12  of various designs and configurations may be provided and an operator may readily change such a rotary punch assembly  10  to a new configuration for successive jobs.  
         [0018]     Referring now to  FIG. 2 , there is shown a second embodiment of the invention. In this embodiment, the cylindrical punch pin roller or pin holder  32  is similarly journaled in bearing supports  38  in roller supports  40  or the like, here shown extending from a base plate  42 . In this embodiment, the punch pins (not visible in this view, but extending from the punch pin roller  32  in a manner similar to that shown in  FIG. 1 ) are received in a longitudinally extending channel  50  in the roller  32 . An elongated locking plate  52  is received in the channel  50  to bear against the heads of the pins to retain them in the proper position in the roller  32 . The elongated locking plate  52 , in turn, is retained in position in the roller  32  by screws  54  that bear against the side of locking plate  52 . In order to prevent the screws  54  from interfering with proper rotation of the roller  32  and punching of sequential sheets, the screws  54  are received in an elongated channel  56  in the roller  32 . It will be appreciated, however, that alternate manners of mounting the pins in the punch pin roller  32  may be provided, or the punch pin roller may be fabricated such that the pins may not be changed out individually, but, rather, are permanently secured to the punch pin roller.  
         [0019]     In order to provide clean punching of the sheets passing between the rollers  32 ,  44 , the optimal separation between the punch pin roller  32  and the lower roller  44  may be adjusted. This adjustment can be particularly important in view of the preferred, resilient material of the lower roller  44 . In the embodiment illustrated in  FIG. 2 , the punch pin roller  32  is adjustable towards or away from the lower roller  44 , although, in other envisioned embodiments of the invention, one or both of the rollers  32 ,  44  may be so adjusted. In this regard, roller tension screws  60  are received in threaded bores  62  in the roller supports  40 . As the roller tension screws  60  are rotated inward, they bear against the surface  64  of the bearing supports  38  to adjust the separation of the rollers  32 ,  44 . To bias the bearing supports  38  toward the roller tension screws  60  and the punch pin roller  32  away from the lower roller  44 , biasing springs  66  are positioned to bear against the lower surface  68  of the bearing supports  38 .  
         [0020]     To assist in removal of the punch pins from the perforated sheet, a stripper plate  70  may be provided at the nip between the rollers  32 ,  44 . In this embodiment, the stripper plate  70  is pivotably mounted to the roller supports  40  by a pivot shaft  72 , the ends of which are received in brackets  74  mounted to the roller supports  40 . The pivoted position of the stripper plate  70  may then be determined by stripper adjustment screws  76  which bear against a surface of the roller supports  40 , the stripper plate  70  preferably being further biased into position by one or more springs (not visible). In this way, the position of the stripper plate  70  may be adjusted to account for variables such at the set separation of the rollers  32 ,  44 , and the thickness of the sheets to be passed between the rollers  32 ,  44 .  
         [0021]     In order to further support the lower roller  44 , particularly when the roller  44  is formed of an entirely resilient material, pairs of lower support rollers  80  are provided along the generally lower surface of the lower roller  44 . One such pair of rollers  80  is shown in the illustrated embodiment. A further pair is preferably provided along the other side of the lower roller  44 , extending upward from the base plate  42  such that the two pairs of rollers  80  cradle the lower roller  44 . The rollers  80  are preferably freely rotating and disposed an adjustable distance from the lower roller  44 .  
         [0022]     In summary, the invention provides a rotary punch arrangement  10  that may be disposed in-line or as a standalone device. It is economical to both operate and maintain, and provides considerable advantages over conventional rotary punch arrangements. The rotary punch arrangement includes a first driven punch pin roller, and a second roller having a relatively softer surface for receiving the punch pins as they perforate the sheets passing between the two rollers. The second roller may be driven or, preferably, it may be freely rotating, eliminating the complexity of standard punch roller arrangements.  
         [0023]     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.  
         [0024]     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.  
         [0025]     Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.