Patent Publication Number: US-6209433-B1

Title: Single revolution die cutter

Description:
This application claims benefit of U.S. Provisional Ser. No. 60/074,260 filed Feb. 10, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates, generally, to rotary die cutting apparatus and methods, and further relates to apparatus and methods for cutting a product sheet. The invention has particular utility in cutting product sheets formed from thick stock such as multi-layer laminates, polymers, or polyurethanes. These product sheets include, but are not limited to, sports cards, school-type portraits, souvenirs and memorabilia. 
     2. Background Information 
     The state of the art includes various devices and methods for cutting a product sheet. These known devices are labor intensive. They are difficult to operate and maintain because of problems related to clearing jams and to replacing the tooling for product changeovers and wear. 
     The present invention provides an economical, durable, and simple apparatus and method for cutting product sheets which is believed to constitute an improvement over existing technology. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an apparatus and method for cutting product sheets formed from thick stock. The apparatus or cutter generally comprises a frame, an anvil roll revolvably attached to the frame, a die roll revolvably attached to the frame and in operable contact with the anvil roll, and a drive mechanism for revolving the anvil roll and the die roll. Both the anvil roll and die roll have a cylindrical body. The anvil roll body has a smooth, hard surface. The die roll has tooling or blades that extend from the body. The anvil roll and die roll are geared together to allow product sheets to be fed between the rolls and cut by the tooling. 
     The frame generally comprises a base, a motor plate attached to the base, a set of opposing anvil bearing blocks attached to the base, and a set of opposing die bearing blocks attached to the anvil bearing blocks. The anvil roll extends between and is revolvably attached to the anvil bearing blocks. Similarly, the die roll extends between and is revolvably attached to the die bearing blocks. The die roll has a pair of spring-loaded pins that are retractable into the body of the die roll. The product sheet is fed into the apparatus and stopped by the pins in a predetermined position with respect to the tooling on the die roll. The pins are preferably rotatable and eccentric. An operator adjusts the predetermined position for stopping the product sheet by rotating the retractable pins. 
     The drive mechanism preferably comprises an electric motor. The motor drives the anvil roll using a belt. An engagement mechanism selectively engages the motor to the anvil roll, thus allowing the motor to run continuously. The engagement mechanism preferably includes a single revolution clutch attached to a journal shaft of the anvil roll. The clutch prevents the motor from driving the anvil roll when it is engaged, and allows the motor to drive the anvil roll for one revolution when it is released. The clutch is preferably actuated by energizing a solenoid. The engagement mechanism may further include a latch mechanism for accurately stopping the rotation of the clutch and the anvil roll after one revolution. The latch mechanism prevents backlash and provides a consistent stop and start position for each revolution, thus enabling the product sheets to be consistently and repeatably processed. The apparatus also includes a transparent upper cover around the die roll. The transparent cover enables the operator to monitor the die cutting process. Additionally, the upper cover and die bearing blocks are constructed and arranged to be quickly and easily removed, providing the operator with the ability to quickly remove and replace the die roll to sharpen the tooling or to perform a product changeover. Furthermore, the fasteners used to attach the die bearing blocks on the anvil bearing blocks provide a means to adjust the load pressure applied by the die roll against the anvil roll. The product sheet is fed along an infeed guide or product placement device into the cutter. Each sheet stops against the spring-loaded pins of the die roll, which is at a predetermined start and stop position. When the clutch is released, the revolving anvil roll and die roll draw the product sheet and cut the product into the desired pattern. The cut product exits into a tray. The product placement device eliminates guesswork by automatically centering the sheet to the tooling on the die roll. 
     The cutter is suitable for use in cutting product sheets of thick stock such as multi-layer laminates, polymers, or polyurethanes. For instance, the cutter can be used to cut sports cards or school portraits. For example, the apparatus can cut individual sports cards from an 8.5″ by 7.5″ sheet containing six cards in two rows and three columns. The cutter is designed to cut sheets ranging in width from 8½ inches to 17 inches. 
     The features, benefits and objects of this invention will become clear to those skilled in the art by reference to the following description, claims and drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a perspective view of a the present invention. 
     FIG. 2 is a perspective view of the drive mechanism and engagement mechanism of the present invention. 
     FIG. 3 is a side view of the frame of the present invention. 
     FIG. 4 is an opposite side view of the frame of the present invention. 
     FIG. 5 is a side view of the present invention without the cover assembly. 
     FIG. 6 is an opposite side view of the present invention without the cover assembly. 
     FIG. 7 is a side view of the engagement mechanism of the present invention. 
     FIG. 8 is an electrical schematic of the present invention. 
     FIG. 9 is a top view of the present invention without the cover assembly. 
     FIG. 10 is illustrates the rotatable eccentric pins in a die roll, and the product placement against these rotatable eccentric pins in a predetermined location with respect to the tooling in the die roll. 
     FIGS. 11 a,    11   b  and  11   c  illustrate the eccentric pins retracting into the cylindrical body of the die roll. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, an example of the preferred embodiment of the present invention is illustrated and generally indicated by the reference numeral  10 . The apparatus for cutting product sheets, or cutter  10 , is described below first in terms of its major structural elements and then in terms of its secondary structural and/or functional elements which cooperate to cut product sheets. 
     Referring now to FIGS. 1,  3 ,  4  and  7 , the cutter  10  generally comprises a frame  12 , an anvil roll  14  revolvably attached to the frame  12 , a die roll  16  revolvably attached to the frame  12  and in operable contact with the anvil roll  14 , and a drive mechanism  18  for driving or revolving the anvil roll  14  and the die roll  16 . As shown in FIG. 5, the product sheets are fed into the cutter  10  in between the anvil roll  14  and die roll  16  along the dotted line marked Product Path. The cylindrically-shaped body surfaces of the anvil roll  14  and die roll  16  press against each other and revolve to draw the product sheets between each other. The body surface of the die roll  16  has tooling, or blades, which cut the product sheets into a predetermined pattern. Additionally, as shown in FIGS. 2,  6  and  7 , the cutter  10  includes an engagement mechanism  20  for selectively engaging and disengaging the drive mechanism  18  from driving or revolving the anvil roll  14  and die roll  16 , and further includes a cover assembly  22  for promoting aesthetics, safety and durability. 
     The frame  12  generally comprises a base  32 , a motor plate  34  attached to the base  32 , a pair of opposing anvil bearing blocks  36  attached to the base  32 , and a pair of opposing die bearing blocks  38  attached to the anvil bearing blocks  36 . The base  32  is preferably a horizontally-oriented, plate-like structure that supports the other elements of the cutter  10 . The motor plate  34  is preferably a vertically-oriented, plate-like structure that is fastened or otherwise attached to the base  32 . The drive mechanism  18 , particularly the motor  72 , is mounted to the base  32  and motor plate  34 . The anvil bearing blocks  36  are likewise fastened or otherwise attached to the base  32 . Needle bearings  42  are pressed into journal openings in each of the anvil bearing blocks  36 . Additionally, at least one of the anvil bearing blocks  36  has a window opening  44  through which an operator can view the alignment of the anvil roll  14 , the die roll  16 , and the product sheet in an assembled cutter  10 . Each of the anvil bearing blocks  36  preferably has an inclined surface  46  upon which the die bearing blocks  38  are attached. The incline surface  46  allows the die roll  16  to be horizontally and vertically offset from the anvil roll  14 , allowing the product sheets to be diagonally fed between the two rolls  14  and  16 . This design simplifies the product input and output devices by utilizing gravitational force. Since the die roll  16  is replaced to sharpen the tooling and to perform product changeovers, it is desirable for an operator to quickly and easily remove and reattach the die bearing blocks  38 . The preferred embodiment uses shoulder bolts  48 , although other fasteners could be used, to quickly attach the die bearing blocks  38  to the anvil bearing blocks  36 . These fasteners are tightened or loosened to adjust the load pressure between the die roll  16  and the anvil roll  14 . The load pressure is preferably optimized to provide a quality cut in the product without undue wear on the tooling, and to prevent the product from walking to one side of the cutter  10  during the cutting process. Additionally, since it is desirable to accurately position the die roll  16  over the anvil roll  14 , the bearing blocks  36  and  38  are preferably keyed together by mating at least one precision-machined aperture and precision-machined pin formed in the blocks  36  and  38 . Needle bearings  42  are pressed into journal openings in each of the die bearing blocks  38 . 
     Both the anvil roll  14  and die roll  16  comprise a generally cylindrically-shaped roll body  52 , an idler journal shaft  54 , and a drive journal shaft  56 . The journal shafts  54  and  56  have a precision fit within the needle bearings  42  in the bearing blocks  36  and  38 . The idler side of the anvil roll  14  has a gear  62  and the idler side of the die roll  16  has a gear  64 . The anvil roll gear  62  and the die roll gear  64  mesh with each other to cause a revolving anvil roll  14  to drive or revolve the die roll  16  in the opposite direction. These gears  62  and  64  may be marked to allow an operator to view and synchronize or time the die roll  16 , the anvil roll  14 , and the product sheet. The die roll  16  has a pair of spring-loaded pins  66  that retract into the body  52  of the die roll  16  when they contact the surface of the anvil roll  14 . These retractable pins  66  position the product sheet in a predetermined position with respect to the tooling on the die roll  16 , and allow the product sheet to be drawn between the two rolls  14  and  16  in a controlled and precise manner. The pins  66  are preferably rotatable and eccentric, allowing an operator to adjust the placement of the product sheet by rotating the pins  66 . Additionally, the pins  66  may have graduated markings to enable an operator to rotate each pin  66  the same amount to prevent the product sheets from skewing as they are fed into the cutter  10 . 
     Referring to FIGS. 2 and 7, the drive mechanism  18  preferably comprises a motor  72 . The motor  72  drives the anvil roll  14  through a timing belt  74  that extends between a motor pulley  76  attached to the motor  72  and a clutch pulley  78  that is attached to the drive journal shaft  56  of the anvil roll  14 . The motor  72  is preferably a fractional horsepower, AC electric motor that, as shown in FIG. 8, operates on common line voltage. 
     The engagement mechanism  20  selectively engages the motor  72  to the anvil roll  14 , thus allowing the motor  72  to run continuously. Referring to FIGS. 2,  7  and  9 , the engagement mechanism  20  preferably includes a single revolution clutch  82  attached to the drive journal shaft  56  of the anvil roll  14  and to the clutch pulley  78 . The clutch  82  prevents the motor  72  from driving the anvil roll  14  when the clutch  82  is engaged or latched, and allows the motor  72  to drive the anvil roll  14  one revolution when the clutch  82  is actuated or released. The clutch  82  has a tine  84  that extends from an exterior surface. When the clutch  82  is engaged, the tine  84  on the clutch and the anvil roll  14  remain stationary. When the clutch  82  is released, the tine  84  on the clutch and the anvil roll  14  revolve. The engagement mechanism  20  also includes a clutch release arm  86  that pivots on an arm stand  88  to move between a clutch release position and an engage position. The arm  86  has a notch  90  on a proximal end which latches with the tine  84  of the clutch  82  when the arm  86  is in the engage position. The clutch  82  is preferably actuated by energizing a solenoid  92 . Alternatively, the clutch  82  could be mechanically actuated with a plunger. In the embodiment shown in FIGS. 2,  6 ,  7  and  9 , the solenoid  92  is attached by a link  94  to the distal end of the arm  86 . The energized or actuated solenoid  92  pulls down on the distal end of the arm  86 , causing the arm  86  to pivot into the release position by raising the proximal end of the arm  86  and by unlatching the notch  90  from the tine  84 . The arm  86  is preferably biased in the engage position with a bias spring  96  that extends between the proximal end of the arm  86  and the stand  88 . 
     The engagement mechanism  20  may further include a latch mechanism, not shown in the figures, for preventing backlash and for consistently and accurately stopping the clutch, the anvil roll and the die roll from revolving after each revolution. The latch mechanism stops the revolving clutch and the anvil roll at a predetermined start and stop point with a predetermined accuracy. An operator can quickly, repeatably and accurately process successive product sheets because the start and stop position of the clutch and anvil roll are known and are accurately controlled. After each revolution, the operator merely places the product sheet on the pins  66  of the die roll  16  to position the product sheet in a desired predetermined position with respect to the tooling on the die roll  16 . The operator then releases the clutch  82  to engage the motor  72  and process the product sheet. 
     The cover assembly  22  generally includes a rear cover  102 , a front cover  104 , and an upper cover  106 . The rear cover  102  is attached to the base  32  and generally covers the drive mechanism  18 , the engagement mechanism  20 , and the anvil roll  14 . The front cover  104  is preferably mounted to the base  32  at a generally vertical mount portion  108 . The front cover  104  also includes an inclined upper portion  110  that extends toward the intersection of the anvil roll  14  and die roll  16 , and further includes an inclined lower tray portion  112  that receives the cut or processed product below the die roll  16 . A scraper blade may be attached to the upper portion  110  to remove any cut product that may cling to the surface of the anvil roll  14 . The upper cover  106  generally covers the die roll  16 . It is preferably transparent or clear to enable the operator to monitor the die cutting process. The upper cover  106  is preferably attached to the die bearing blocks  38  using knurled screws  114 . These screws  114  allow an operator to quickly access and remove the die roll  16 . A limit switch  116  is wired into the electrical circuit to prevent the cutter  10  from operating with the upper cover  106  removed. A product placement device or infeed tray  118  may be mounted onto the anvil bearing blocks  36  to properly feed the product sheet between the rolls  14  and  16 . The infeed tray  118  shown in the figures auto centers the product sheet with respect to the tooling on the die roll  16 . 
     The cutter  10  utilizes an operator interface with few controls, thus simplifying the process of cutting product sheets. The controls of the cutter  10  include a lighted power switch  122  and a cycle switch  124 . The power switch provides current to the electric motor  72 . However, the engaged clutch  82  prevents the anvil roll  14  and the die roll  16  from revolving. The cycle switch  124  energizes the solenoid  92 , which temporarily releases the clutch  82  allowing the anvil roll  14  to rotate for one revolution. The cycle switch  124  may take a variety of forms, including a finger actuated switch as shown in the figures or a foot-actuated switch. Referring to FIGS. 1 and 8, the cutter  10  operates on common line voltage and is wired with an easily replaceable fuse  126 . 
     An operator performs the following steps to cut photographic prints. First, the operator turns on the motor by pressing the power switch. The motor may run continuously through the process. Second, the operator sets a product sheet in an infeed tray to feed the product sheet between the anvil roll and the die roll of the cutter. The product sheet rests on the eccentric, spring-loaded retractable pins on the die roll. These pins may be rotated to adjust the position of the edge of the product sheet with respect to the tooling on the die roll. Third, the operator actuates the cycle switch to engage the motor and revolve the anvil roll and the die roll. The cycle switch moves a clutch release arm into a release position and unlatches or releases the clutch. The product is drawn between the rolls and cut by the tooling on the die. 
     The descriptions above and the accompanying drawings should be interpreted in the illustrative and not the limited sense. While the invention has been disclosed in connection with the preferred embodiment or embodiments thereof, it should be understood that there may be other embodiments which fall within the scope of the invention as defined by the following claims. Where a claim, if any, is expressed as a means or step for performing a specified function it is intended that such claim be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof, including both structural equivalents and equivalent structures, material-based equivalents and equivalent materials, and act-based equivalents and equivalent acts.