Patent Publication Number: US-2005132865-A1

Title: Cutting system with enhanced cutting blade depth control

Description:
BACKGROUND  
      This invention relates to a cutting system with enhanced cutting blade depth control. The invention has importance in the custom framing mat industry or other industries where flat sheets of material require cutting. Custom framing mats with various shaped and sized openings are highly desirable to customers having uniquely sized photographs or paintings. Additionally, mat purchasers desire mats with decorative cuts. These mats by their very custom nature cannot be off the shelf mass-produced items. Local hobby and craft stores require cutting systems that may provide mats with varying cutouts or openings as well as decorative cuts carved into the mats. Systems having cutting blade depth control provide increased flexibility and customer satisfaction. The cutting system of this invention may be used for mat cutting as well as other material cutting applications where fine control of blade depth is important. Too little cutting depth will not allow a complete cut through a mat or other material while too much cutting depth may cause ragged or rough surfaces on at least one face of the cut material. Too much cutting depth may inhibit a cutting system from making decorative grooved cuts that may not be cuts all the way through the material.  
     SUMMARY  
      The cutting system includes a two dimensional X-Y axis carrier system for transporting the blade control mechanism around a cutting board or support frame. The support frame holds the item to be cut, which may be a paper, cardboard, or synthetic material. The blade control mechanism includes a hollow shaft blade cutting direction motor. The hollow shaft motor has a hollow shaft that has at least one end protruding from the motor. This protruded portion of the hollow shaft is directed towards a mat holding area of the support frame when the blade control mechanism is installed in the X-Y carrier. The protruded portion of the hollow shaft of the blade control mechanism is engaged to a blade holder for rotating the blade holder. The blade holder may be engaged to a blade. As the blade control mechanism is carried around the X-Y axis of the cutting board or support frame, the hollow shaft motor rotates the blade using the hollow shaft and the blade holder through 360 degrees of movement. The blade cuts tangent to the curve it is cutting or cutting a straight line.  
      A depth control or plunge rod is engaged at one end to a depth control operator. The plunge rod passes through the hollow shaft of the hollow shaft motor to contact a blade carrier portion of the blade holder. When the depth control operator drives the plunge rod into and through the hollow shaft, the plunge rod in turn increases effective blade extension from the blade cutter by pushing and sliding the blade outwards along the blade carrier portion of the blade holder. The depth control operator may be a pneumatic or hydraulic cylinder that allows for movements of the blade for different blade cutting depth or cutting height adjustments. In the alternative, the depth control operator may be a linear motor that may allow for infinite blade cutting depth variations within the blade movement range. The depth control operator, whether pneumatic, hydraulic, or electric motor driven may be driven manually as well as from a computer programmed for a design or cut.  
      Additional effects, features and advantages will be apparent in the written description that follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:  
       FIG. 1  is a top down view of a carrier system for transporting the blade control mechanism around a cutting board or support frame;  
       FIG. 2  is a first embodiment of a blade control mechanism using pneumatics for controlling blade depth for use with the carrier system of  FIG. 1 ;  
       FIG. 3  is a second embodiment of a blade control mechanism using an electric motor for controlling blade depth for use with the carrier system of  FIG. 1 ;  
       FIG. 4  is a third embodiment of the a blade control mechanism using pneumatics for controlling blade depth for use with the carrier system of  FIG. 1 ; and  
       FIG. 5  is a side view of a blade holder for the blade control mechanisms of  FIGS. 2, 3 , and  4 .  
       FIG. 6  is a different cutaway side view of the blade holder of  FIG. 5 .  
       FIG. 7  is a rear quarter perspective of the blade holder of  FIG. 5 .  
       FIG. 8  is the rotating cam for the blade holder of  FIG. 5 .  
       FIG. 9  is an upper perspective of the blade carrier of  FIG. 5 .  
       FIG. 10  is a lower perspective of the rotating cam and blade carrier for the blade holder of  FIG. 5 .  
       FIG. 11  is a simplified version of the blade holder of  FIG. 5 . 
    
    
     DETAILED DESCRIPTION  
      A cutting system as shown in  FIG. 1  includes a two dimensional X-Y axis carrier system for transporting the blade control mechanism  101 ,  201 , or  301  around a cutting board or support frame  130 . The support frame  130  may hold an item or sheet of material to be cut, which may be a paper, cardboard, or synthetic piece of material such as mat board. Various forms of X-Y carrier systems may be applicable. The X-Y carrier system shown in  FIG. 1  may include an X motive carrier driver  132  that may drive along an X pathway or drive rod  134 . Additionally the X-Y carrier may have a Y motive carrier  131  that may drive along a Y pathway or drive rod  133 . It should be emphasized that this X-Y carrier is only one example and that other embodiments may include other methods to drive a cutting blade control mechanism about a support frame and still be covered by this invention. For instance, the Y motive carrier and the X motive carrier could easily be the same driving unit and rails may not be necessary nor do rails when used have to be engaged to the support frame  130 .  
      The blade control mechanism  101 ,  201 , or  301  includes a hollow shaft blade cutting direction motor  102  with a hollow shaft  103 . The hollow shaft  103  has at least one protruded end portion  104  protruding from the hollow shaft motor  102 . This protruded end portion  104  of the hollow shaft  103  is directed towards a mat holding area of the support frame when the blade control mechanism  101  or  201  is installed in the X-Y carrier  130 .  
      The protruded portion  104  of the hollow shaft  103  of the blade control mechanism  101  or  201  is engaged to a blade holder  105  for rotating the blade holder  105  and hence determining the cutting direction of a blade  108 . The blade holder  105  may be engaged to a blade  108 . The blade  108  may be a razor type knife or other blade capable of piercing and cutting the work material. In the preferred embodiment, the blade  108  is at a 45-degree angle from the cutting surface when the material to be cut is a mat board, although this angle may vary depending on the material to be cut and varying thickness.  
      As the blade control mechanism  101 ,  201 , or  301  is carried around the X-Y axis of the cutting board or support frame  130 , the hollow shaft motor  102  rotates the blade  108  using the hollow shaft  103  and the blade holder  105  through 360 degrees. Where the hollow shaft motor  102  is a stepper motor known in the art of electronics, it has the capability of rotating the blade  108  through these 360 degrees in over 3000 discrete movements. This allows flexibility in cut designs due to the increased variability of these blade steering movements. The blade cuts tangent to the curve it is cutting or cutting a straight line.  
      A depth control or plunge rod  106  is engaged at one end to a depth control operator  119  or  219  or  319 . The depth control operator  119  may be connected to the hollow shaft motor  102  although this is not a necessity. The plunge rod  106  passes through the hollow shaft  103  of the hollow shaft motor  102  to contact a blade carrier portion  109  of the blade holder  105 . When the depth control operator  119  or  219  drives the plunge rod  106  into and through the hollow shaft  103 , the plunge rod  106  in turn increases effective blade extension from the blade cutter by sliding the blade  108  outwards along the blade carrier portion  109  of the blade holder  105 . The blade carrier portion  109  may be slide channel formed to allow movement of the blade  108  through it. When the depth control operator  119  withdraws the plunge rod  106  through the hollow shaft  103 , a spring or other potential energy storing mechanism will force the blade  108  back up the blade carrier portion  109  of the blade holder  105 . Thus the depth of the blade extension is reduced and the blade  108  is withdrawn fully or partially into the blade holder  105 . The spring may uniquely be a compression spring.  
      In one embodiment, the blade holder  105  may be similar to the unique design shown as blade holder as shown in FIGS.  5  to  11 . In this embodiment the blade ( 108 ) is not locked in firmly until the final rotation of a rotating cam. The rotating cam incorporates a pin  250  located in slots ( 251 ). Cam ( 243 ) is used to lock shaft in open position. There is a blade cartridge  240  upon which a blade is installed. There is a foot  245  through which the blade is inserted outward. The cam  243  has rotating shaft  244 . The rotating shaft  244  passes through the outer walls of the housing as well as through the blade carrier ( 260 ). There is a slot  236  in the outer walls of the (housing)  205  allowing insertion movement of the rotating shaft  244  as well as the carrier ( 260 ). The blade cartridge  240  as shown in  FIG. 10  has a magnet  140  on one face for engaging the blade  208 . The blade cartridge  240  contains a blade slot  261  for engagement of the blade  208 . The blade cartridge  240  has a locking notch  252 . This locking notch  252  is important for accomplishing the final rotation locking of the pin  250  in slot  251 . The blade cartridge  240  has a magnet for initial holding of the blade. This cartridge  208  is inserted into the blade cartridge carrier ( 260 ) until the locking notch  252  aligns with the locking pin ( 250 ) located on the shaft  244  at which time the shaft rotates and the locking pin ( 250 ) falls into the slot and is forced there with the pressure of a torsion spring  271  and wedging the blade and blade cartridge into place. The torsion spring applies a rotational force upon the shaft  244 . For this embodiment, the plunge rod  106  is similar to the plunge rod  106  above. The depth control operator drives the plunge rod  106  downward passing side support  230 . The plunge rod  106  initially contacts the blade cartridge carrier  260 , moving the unit with the blade  208 , the blade cartridge ( 240 ), and the blade cartridge carrier ( 260 ) downward along the slot  236  formed within the housing  205  and placing the blade into a cutting position.  
      The following explanation should help clarify the operation of the blade holder  105  structure described above. The plunge rod  106  only moves in an upward and downward direction. The plunge rod  106  only pushes on a horizontal angle slide pin  242 . The blade cartridge carrier ( 260 ) slides at a 45 degree angle down and forward as the plunge rod  106  pushes on the pin  242 . The pin  242  slides across the bottom of the plunge rod  106  as the plunge rod is moving downward allowing the carrier ( 260 ) attached to it to move downward at a 45 degree angle carrying the blade cartridge ( 204 ) and blade ( 208 ) with it into cutting position. The mechanism  101  or  102  is imparting only a downward force with the plunge rod  106  but since the rod  106  is pushing on pin ( 242 ) mounted on the carrier ( 260 ) it is converting a vertical downward force to a 45-degree downward force. The blade  208  is mounted on the blade cartridge  240 , which is removed from the carrier  260  for replacing the blade  208 . The blade cartridge ( 240 ) is inserted into a sliding cartridge carrier ( 260 ), which moves downward and forward by force from the plunge rod carrying the blade cartridge  240  and blade  208  with it. The following items are meant to securely hold the blade cartridge  240  in place during cutting. A handle  270  on the end of the shaft ( 244 ) is rotated until a semicircular notch ( 264 ) in the cam shaped disc  243  aligns with a pin  263  protruding from the side of the housing ( 205 ) and the notch  264  falls over the pin  263  therefore locking the unit open so the blade cartridge  240  can be removed. After a new blade is placed in the blade cartridge ( 240 ) (being held in place temporarily with a magnet  140 ) the blade cartridge ( 240 ) is inserted into a matching slot in the blade cartridge carrier ( 260 ). There is a small locking pin  250  mounted horizontally on the rotating main shaft  244  that will eventually line up with a slot  252  on the back of the blade cartridge ( 240 ). As the blade cartridge ( 240 ) is manually pushed forward into the blade cartridge carrier ( 260 ) the force exerted will push the blade cartridge carrier ( 260 ) forward and cause the semi circle notch  264  in the cam  243  to be lifted off the pin  263  that was holding it in place and a torsion spring  271  mounted on the side of the housing ( 205 ) and connected to the main shaft will cause the main shaft  244  to rotate and the locking pin ( 250 ) will fall into the slot  252  on the back of the blade cartridge  240 . Due to the large force of the tension spring  271  and the close proximity of the locking pin  250  so close to the center of rotation of the main shaft  244  it creates a very large lever advantage at the locking pin  250  therefore holding the blade cartridge ( 240 ) firmly in place. Since the blade  208  thickness is slightly thicker than the blade indented area or blade receiving slot  261  on the blade cartridge  240  the blade  208  is firmly pushed against the blade cartridge  240  and therefore locking the blade  208  in place while plunging and un-plunging into and out of the mat board.  
      The Blade Cartridge ( 240 ) with magnet  140  carries and holds the blade ( 208 ) in precise cutting position. As the cartridge ( 240 ) is inserted into the carrier ( 260 ) the thin end ( 210 ) end slides under the shaft ( 244 ) until it stops against the shaft ( 244 ) at the ledge created at the notch ( 252 ). When slightly more force is exerted by the operator, it causes the carrier ( 260 ) to move forward along with the shaft ( 244 ). This continued forceful movement causes the semicircle ( 264 ) in the cam ( 243 ) to disengage from the pin ( 263 ), allowing the shaft  244  to rotate powered by the torsion spring  271 , therefore causing the locking pin ( 250 ), that is part of the shaft ( 244 ), to engage slot ( 252 ) in the cartridge. The Blade cartridge Carrier ( 260 ) carries the blade ( 108 ) and blade cartridge ( 240 ) at a 45-degree [or other angle] angle relative to the mat board. The shaft  244  engages a loose hole in the carrier ( 260 ) to allow rotation for locking. The shaft  224  then rotates to allow clamping of blade cartridge ( 240 ) and blade ( 208 ). The shaft  244  has cam ( 243 ) on end to allow locking in the open position for changing blades and the shaft contains a small horizontal offset locking pin ( 250 ), which snaps into slot ( 251 ). This pin  250  acts like a cam that engages into the slot ( 252 ) in the blade cartridge ( 260 ) thereby clamping the blade cartridge and blade in place when the shaft ( 244 ) is rotated. A finger handle  270  is attached to the end of the shaft ( 244 ) for rotating shaft into an open position-engaging semicircle ( 264 ) with pin ( 263 ) to allow removal of the blade cartridge and blade. See  FIG. 11 . A torsion spring  271  is held in place between this handle and the housing (not pictured) to provide energy for the blade locking. There is a head block (not pictured) connected to the motor shaft ( 104 ) and provides support and alignment for all other members. The head block actually does nothing except attach the entire assembly to the motor shaft. It is the housing ( 205 ), which surrounds the head block that contains the slot ( 252 ), locking pin ( 263 ) and a lower polished surface for the blade cartridge carrier ( 260 ) to slide on. The Housing ( 205 ) surrounds the head block and holds and aligns the Block (not shown) and other parts and contains a slot  236  on the side of the housing (not pictured) that allows the shaft ( 244 ) to slide forward at 45 degrees and a pin ( 263 ) to allow the cam ( 243 ) to engage for holding shaft ( 244 ) in open position for blade changes. The Locking Pin ( 250 ) fits in notches ( 251 ) and rotationally engages in slot ( 252 ) of the blade cartridge ( 240 ) for locking blade cartridge and blade into position.  
      The rotating shaft  244  of the cam  243  has a semi-circular region and locking pin are  250  in the middle area. The semi-circular region or edge carrying region may have notches  251  with a pin  250  that acts as a cam at the interface with the circular end regions of the rotating shaft  244 . The blade cartridge  208  has a magnet for initial holding of the blade. This cartridge  208  is inserted into the blade cartridge  240  until the locking notch aligns with the rotating shaft of the cam  243 . At which time a torsion spring  271  rotates the cam  243  locking the blade cartridge  208  and wedging the blade into place. For this embodiment, the plunge rod  106  is similar to the plunge rod  106  above. The depth control operator drives the plunge rod  106  downward passing side support  230  that is engaged to slots  232  in the back wall  231 . The plunge rod  106  initially contacts the blade cartridge  240 , moving the unit with the blade  208 , the blade cartridge, and the blade cartridge  240  downward along the slot  236  in the outer walls of the blade holder  205  and placing the blade into a cutting position.  
      The following explanation should help clarify the operation of the blade holder  205  structure described above. The plunge rod  106  only moves in an upward and downward direction. The plunge rod  106  only pushes on a horizontal angle slide pin  242  mounted on the blade cartridge carrier  240 . The blade cartridge carrier  240  slides at a 45 degree angle forward as the plunge rod  106  pushes on it and the pin  242  slides along the bottom end of the plunge rod  106  as it moves the pin  242  forward and down at 45 degrees. The mechanism  101  or  102  is imparting only a downward force with the plunge rod  106  but since the rod  106  is mounted on the sliding carrier  240  it is converting a vertical downward force to a 45-degree downward force. The blade  208  is mounted on the blade cartridge  240 , which is removed from the foot block  260  for replacing the blade  208 . The blade cartridge  208  is inserted into a sliding cartridge carrier  240 , which moves downward and forward by force from the plunge rod carrying the blade cartridge  240  and blade  208  with it. The following items are meant to securely hold the blade cartridge  240  in place during cutting. A handle  270  on the side of the foot block  260  is rotated until a semicircular notch  264  in the cam shaped disc  243  aligns with a pin  263  protruding from the side of the foot block  260  and the notch  264  falls over the pin  263  therefore locking the unit open so the blade cartridge  240  can be removed. After a new blade is placed in the blade cartridge  208  (being held in place temporarily with a magnet  140 ) the blade cartridge  208  is inserted into a matching slot in the blade cartridge carrier  240 . There is a small locking pin  250  mounted horizontally on the rotating main shaft  244  that will eventually line up with a slot on the back of the blade cartridge  208 . As the blade cartridge  208  is manually pushed forward into the blade cartridge carrier  240  the force exerted will push the blade cartridge carrier  208  forward and cause the semi circle notch  264  in the cam  243  to be pushed off the pin  263  that was holding it in place and a torsion spring  271  mounted on the side of the foot block and connected to the main shaft  244  will cause the main shaft to rotate and the locking pin  250  will fall into the slot  252  on the back of the blade cartridge  240 . Due to the large force of the torsion spring  271  and the close proximity of the locking pin  250  so close to the center of rotation of the main shaft  244  it creates a very large lever advantage at the locking pin  250  therefore holding the blade cartridge  208  firmly in place. Since the blade  208  thickness is slightly thicker than the blade indented area or blade receiving slot  261  on the blade holder  240  the blade  208  is firmly pushed against the blade cartridge carrier  240  and therefore hopefully locking the blade  208  in place while plunging and un-plunging into and out of the mat board.  
      The depth control operator may be a pneumatic cylinder system  119  that allows for discrete or finite movements or of the blade  108  for different blade cutting depth or cutting height adjustments. This is shown in the embodiment shown in  FIG. 2 . A cylinder shaft  107  is engaged at one end to the end of the plunge rod  106  opposite to that attached to the used to push to extend the blade  108 . The cylinder shaft  107  is engaged at its other end to the internal piston  121  of the pneumatic cylinder. The piston  121  moves within an operating chamber  120  of the pneumatic cylinder  119 . An air supply A is applied through an air operator  122  to an upper side of the piston  121  to apply blade extension force through the cylinder shaft  107 , and the plunge rod  106  through the hollow shaft  103  to the blade  108  along the blade carrier  109 . The pneumatic cylinder  119  could easily be replaced with a hydraulic cylinder that would apply blade extension force through the application of hydraulic fluid from a source A to a piston  121 . Potential energy is stored in a spring upon application of air A to the upper side of the piston  121  and when air is vented from the upper side of the piston  121 , the spring forces the piston  121  in a direction to retract the blade  108  or reduce blade  108  extension.  
      The depth of blade  108  plunge may be adjusted manually through a pneumatic cylinder knob or adjuster  124  that rotates an end stop shaft  123  to raise or lower an end stop  125 . The end stop  125  has an upper stop surface. The lower portion of the piston  121  comes to rest against the upper stop surface of the end stop  125  at the predetermined blade extension stop. The predetermined blade extension stop may be set by the pneumatic cylinder knob  124  adjustment of the height of the end stop  125 . The adjustable end stop  125  makes the pneumatic cylinder  119  have a variable effective size due to the varied piston  121  movement.  
      In the embodiment shown in  FIG. 4 , there is a different blade plunge limiter. In this preferred embodiment, depth of blade  108  plunge may be adjusted manually through a second pneumatic cylinder knob or adjuster  324  that rotates about a head top plate  323  of the blade control mechanism  301 . The second pneumatic cylinder knob  324  is stationary in the vertical direction. There are internal threads  331  on the inner chamber walls of the second pneumatic cylinder knob  324  on which a movable cylinder  319  rides upwards or downwards depending on the rotation of the second pneumatic cylinder knob  324 ; the movable cylinder  319  having external threads  341  to match the internal threads  331  of the second pneumatic cylinder knob  324 . The movable cylinder  324  not rotating due to an anti-rotation pin  321  that is fixed in the radial direction to an internal portion of the blade control mechanism  301 . The movable cylinder  324  has internal piston  321  that rides up or down on the inner walls of the movable cylinder  319  about sealing rings  326 . The internal piston  321  is engaged to the cylinder shaft  107  to operate the blade  108  of the blade holder in a similar fashion as described above in the blade control mechanism  101 . The movable cylinder  319  has an air supply A and an internal air line  322  that leads to the operating area  320  of the movable cylinder. The movable cylinder  319  has a lower piston stop area  329  against which the internal piston  321  stops at upon being downward driven. Rotation of the second pneumatic cylinder knob  324  raises or lowers the movable piston  321  that in turn varies the piston stop area  329  and hence varies the plunge depth of the amount of plunge rod  106  movement and hence blade  108  movement. The predetermined blade extension stopping point being set by the pneumatic cylinder knob  324  adjustment of the height of the piston stop area  329 .  
      In one commercialized embodiment, the cylinder knob or adjuster is located on top of the cylinder  119  head and is calibrated in 24 segments. Each segment represents a 0.006-inch plunge of the blade  108  through a material to be cut. If the material is mat board, its thickness may vary from 0.050″ to 0.200″ and the desired blade protrusion through the backside of the mat would be 0.010″ to fully cut out the opening. In situations where decorative cuts are made in the face of the mat without cutting all the way through, the blade is set for a depth that is less than the overall mat thickness. The cutting mechanism  101  or  201  is then directed for return pass in the other direction. An angled blade  108  allows for such Vee channels to be cut into the face of the mat material. The pneumatic cylinder knob  124  in this one embodiment is designed to rotate the end stop  125  through the end stop shaft  123  to the desired location to achieve the desired blade  108  depth. The cutting system described here is in no way limited to the above specifications. This commercialized embodiment is only described as way of example of a preferred but not the only workable embodiment of a cutting system.  
      The depth of the blade  108  plunge may also be adjusted automatically through an external driver unit such as pneumatics, hydraulics, electromagnets, or motor which would take the place of the pneumatic cylinder knob  124 .  
      In an alternative embodiment, the depth control operator may be a linear motor  219  that may allow for infinite blade cutting depth variations within the blade movement range. This is shown in the embodiment in  FIG. 3 . The linear motor  219  in this embodiment is engaged to a motor shaft  207  that takes the place of the cylinder shaft  107  described in the above embodiment. This arrangement creates some advantages. Since the depth of the blade  108  is controlled by a linear motor such as a small stepper motor that may be controlled by a computer  111 , the users of the cutting system may be able to precisely control the depth of the blade while the blade  108  is cutting the material. The user may therefore better control the designs she produces in the mat board surface. Sometimes the user may direct the cutting system to cut all the way through and sometimes it will be cutting variable depth Vee grooves. The linear motor  219  allows the computer  111  to be pre-programmed for various thickness of mat board from different manufacturers of mat board. The linear motor  219  may be either a servo or stepper motor.  
      The depth control operator electric motor  219  driven may be driven manually as well as from a computer  111  programmed for a design or cut. The hollow shaft motor may also be driven by a computer or chip  111  programmed to coordinate the three dimensions of cuts in materials; the hollow shaft motor  102  controlling the X and Y direction, the X-Y carrier system X-Y location and the depth control operator controlling the Z or height axis.  
      As described above, the embodiments of the cutting system provide a number of advantages, some of which have been described above and others of which are inherent in the invention. Also modifications may be proposed to the embodiments of the cutting system without departing from the teachings herein.