Abstract:
A blade shank that can be used for cutting corrugated sheets incorporating improvements to blade design and cutting geometries for an improved cutting action on corrugated sheets; that may include a handle, but does include a blade shank or blade base, at least one cutting edge, at least one guide member attached to the blade base or blade shank; the blade shank can be attached to a handle with the cutting edge facing rearward while the guide member is directed rearward wile the guide member straddles the cutting edge or edges.

Description:
FIELD OF THE INVENTION 
     The present invention relates to specialty knife blades, in particular, relates to specialty knife blades for the sign industry used for cutting and trimming corrugated plastic sheets for signs. 
     BACKGROUND OF THE INVENTION 
     Corrugated plastic sheets are used in the sign industry as a backing for signs. This material is made up of a series of flutes connected side by side to form corrugated sheets. This material can be printed on or used as a low cost backing for a sign. This material usually needs to be trimmed or cut to size. Typically a box cutter type knife with a straight edge can be used to cut against the flutes. When cutting with the flutes, an unsightly cut will result if the knife hits a sidewall of the flute causing the knife to “jump flutes”. Most of the time, the flutes are not perfectly straight because of the extruded manufacturing process. They can incorporate a slight wave so it is close to impossible to cut the length of a sheet without crossing a flute wall with a standard box knife and straight edge. 
     This difficulty in cutting with the flutes was the need that has been filled by a “flute knife” or “flute cutter”. The typical flute knife uses guide members that are attached to a blade and the blade is attached to a handle. The guide member is sized to fit into the flute of the corrugated plastic sheet. It is inserted into the flute and is used to guide the cutting blade as the user pulls the knife through the material. A second guide member, on the end of the blade is used when the user wants to cut one side of the fluted material so he can make a bend or hinge the material. 
     There are short comings with current flute cutter operation. 
     Flute cutters need an increased or disproportionate force to initially penetrate a flute wall of a corrugated sheet than the force needed to maintain the cut once started in that sheet. 
     Flute cutters must have the guide member go straight down the flute tube. If the guide member is not aligned in the flute tube while cutting, it presses against the top or bottom wall of the tube, increasing friction and slowing or stopping the cutting process. 
     The handle and guide member are at a specific angle when constructed. If the handle is not maintained at that specific angle during the cut, the guide member will press against the top or bottom wall slowing or stopping the cutting process. 
     Maintaining this critical angle with a traditional flute cutter is awkward and fatiguing. Many times the material is held by hand or the material is leaning against a wall while the user tries to rip its length. 
     Cutting thicker walled material with a larger traditional flute cutter is close to impossible. The thicker walls of the 10 mill corrugated sheet close on the blade and pinches it during a cut increasing the resistance requiring a Herculean effort by the user. 
     No flute cutter has a replaceable cutting blade or blade shank. Currently when the flute knife blade dulls out, it is discarded in its entirety including the handle. 
     There is no flute cutter that has interchangeable guide members to allow for the cutting of different size corrugated plastic sheets. 
     PRIOR ART 
     There are two flute knife designs currently being sold in volume. The first is the Saw Trax Coro Claw flute knife. It uses an ergonomically shaped grip in an elliptically shaped handle. It has a short blade shank incorporated into the plastic handle. The second flute knife is the Plast-Kut flute knife. It&#39;s blade shank runs the entire length of the knife and has plastic sides molded to the shank to form a handle area. Both knives use rivets to attach their pair of guide members to the blade shank. The angle of the guide member to handle of the two cutters is different, but both operate the same way and both must be careful to maintain the angle of handle to guide member during use. 
     SUMMARY OF THE INVENTION 
     This invention shows improvements to flute knife design and cutting geometries for an improved and easier cutting action on corrugated sheets. 
     The issue of increased force to initiate a cut versus maintaining the cut is addressed by staggering the cutting edge on either side of the guide member. By doing so, only one wall of the corrugated sheet is cut at a time upon entry into the corrugated sheet by the flute knife. 
     Guide member alignment in the corrugated material is addressed by a variable angle guide member or by using a quillion for material alignment with the guide member. 
     The dulling of the cutting edge of the blade shank is addressed by varying the position of the guide member on the cutting edge creating a new cutting point and/or by incorporating a separate and replaceable cutting edge while keeping the same blade shank base and same handle. 
     The cutting of different sized corrugated sheets is addressed with interchangeable guide members of different sizes. 
     The cutting of larger and thicker walled corrugated sheets is addressed by a beveled blade design that prevents the wall of the corrugated material from closing on and pinching the blade shank. Unlike a saw, that cuts a section out of a material leaving room for the blade as it cuts, a knife slices material and pushes the sides out of the way as it cuts. When cutting thicker walled corrugated plastic sheets, the wall sides of the sheet close on the knife shank as it cuts. This closing action greatly increases the friction on the knife blade and the force required to push the blade through the material. The point of beveling the blade in the guide member as it cuts a corrugated sheet is to prevent the pinching action of the cut sides on the blade shank. The bevel cut of a knife blade forces the individual flute wall side up and down on either side of the blade shank as it passes. This greatly reduces the friction and force needed to push the blade though the corrugated sheet as opposed to pinching action from cutting the sheet with the blade at a 90 degree angle. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
       Preferred embodiments of the invention are shown in the drawings, wherein; 
         FIG. 1  is a side view of an embodiment of a blade shank; 
         FIG. 2  is a side view of an embodiment of a blade shank showing a second guide member. 
         FIG. 3A  is a side view of an embodiment of a blade shank showing a material guiding edge with a handle. 
         FIG. 3B  is a side view of an embodiment of a blade shank showing a material guiding edge and a detachable blade shank and a different type handle. 
         FIG. 4A  is a side view of an embodiment of a blade shank showing a pivoting guide member. 
         FIG. 4B  is a side view of a second embodiment of a blade shank showing a pivoting guide member. 
         FIG. 5  is a side view of an embodiment of a blade shank showing different positions for a guide member. 
         FIG. 6  is a side view of an embodiment of blade shank showing interchangeable guide members. 
         FIG. 6A  is a front view of the guide member showing a slot and fasteners for attaching. 
         FIG. 7  is a side view of an embodiment of blade shank showing a replaceable cutting edge. 
         FIG. 8  is a side view of an embodiment of blade shank showing a replaceable cutting edge with a material guiding edge. 
         FIG. 9A  is a side view of an embodiment of blade shank showing a replaceable and reversible cutting edge that is angled on different sides of the guide member. 
         FIG. 9B  is a side view of a second embodiment of blade shank showing a replaceable and reversible cutting edge that is angled on different sides of the guide member. 
         FIG. 10  is a side view of an embodiment of blade shank showing a replaceable angled cutting edge with a pivoting guide member. 
         FIG. 11  is a side view of an embodiment of blade shank showing a replaceable cutting edge with a guide member that can be repositioned on the blade shank. 
         FIG. 12A  is a top view of a beveling blade in a guide member. 
         FIG. 12B  is a side perspective view of a beveling blade in a guide member. 
         FIG. 13  is a top view of a beveling blade in a guide member that has a bend allowing a handle to be at a right angle to the side of the guide member. 
         FIG. 14  is a top view of a beveling blade in a guide member with multiple bends to bevel cut in opposite directions on opposing sides of the guide member. 
         FIG. 15  is a top view of a beveling blade in a guide member with multiple bends to bevel cut in opposite directions on opposing sides of the guide member with a second guide member attached to the end of the blade. 
         FIG. 16  is a side view of a beveling and angled blade shank. 
         FIG. 17  is a front view of a blade shank showing independent sides of a guide member attached to the blade shank. 
         FIG. 18A  is a top view of a beveling blade shank that has different sized independent sides and their position on the blade shank. 
         FIG. 18B  is an exploded top view of a beveling blade shank that has different sized independent sides and the fasteners to attach them. 
         FIG. 19  is a top view of a beveling blade shank in a corrugated sheet during a cut showing what happens to the cut walls of the corrugated sheet. 
         FIG. 20  is a top view of a beveling blade shank in a handle in a corrugated sheet during a cut showing how the sizing of the independent sides can position the cut in the flute of the corrugated sheet. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Beginning with  FIG. 1 , a blade shank  10  that can include a handle  11  is shown. The handle  11  would be attached to a blade shank  12  such that the blade shank extends from the forward end of handle  11 . Blade shank  12  is ground to include two staggered cutting edges,  14  and  15  on its rearward facing side. Each of cutting edges  14  and  15  have been ground on opposite sides of blade shank  12 . Blade shank  12  is preferably made from spring metal or stainless steel. A guide member  13 , extends beyond blade shank  12 &#39;s rearward edge and is positioned between cutting edges  14  and  15 . The guide member  13  can be made from metal or plastic. Fasteners  16  can be used to attach guide member  13  to blade shank  11  if guide member  13  is made of metal. 
       FIG. 2  shows a blade shank  20  that can include a handle  21 . The handle  21  would be attached to a blade shank  22  such that the blade shank extends from the forward end of handle  21 . Blade shank  21  is ground to include two staggered cutting edges,  24  and  25  on its rearward facing side. Each of the cutting edges  24  and  25  have been ground on opposite sides of blade shank  22 . Blade shank  22  is preferably made from spring metal or stainless steel. A first guide member,  23 , extends beyond blade shank  22  rearward and is positioned between cutting edges  24  and  25 . A second guide member  27  is attached to the edge of blade shank  22  and points rearward. Second guide member  27  acts as a guard on cutting edge  24  and is used to cut a single flute wall for hinging or bending corrugated sheets. The guide members  23  and  27  can be made from metal or plastic. Fasteners  26  are used to attach guide member  23  and  27  to blade shank  21  if guide members  23  and  27  are made of metal. 
       FIG. 3A . shows a blade shank  30  that can include a handle  31 . The handle  31  can be attached to a blade shank  32  such that the blade shank extends from the forward end of handle  31 . Blade shank  32  is ground to include two staggered cutting edges,  34  and  35  on its rearward facing side. Each of said cutting edges  34  and  35  have been ground on opposite sides of blade shank  32 . Blade shank  32  is preferably made from spring metal or stainless steel. A guide member,  33 , extends beyond blade shank  32  rearward and is positioned between cutting edges  34  and  35 . The guide member  33  can be made from metal or plastic. Fasteners  36  are used to attach guide member  33  to blade shank  32 . A guiding edge  38  is shown as an integral part of handle  31  or blade shank  32 . When blade shank  32  is attached to handle  31 , guiding edge  38  is parallel to guide member  37  and spaced from guide member  37  an amount that would leave a cutting gap slightly larger than a wall thickness of the corrugated material to be cut. 
       FIG. 3B  shows a blade shank  30  that can include a handle  31 . The handle  31  can be attached to a detachable blade shank  32 , shown separated, such that the blade shank extends from the forward end of handle  31 . Blade shank  32  is ground to include two staggered cutting edges,  34  and  35  on its rearward facing side. Each of said cutting edges  34  and  35  have been ground on opposite sides of blade shank  32 . Blade shank  32  is preferably made from spring metal or stainless steel. A guide member,  33 , extends beyond blade shank  32  rearward and is positioned between cutting edges  34  and  35 . The guide member  33  can be made from metal or plastic. Fasteners  36  are used to attach guide member  33  to blade shank  32 . A second guide member  37  is attached to the edge of blade shank  32  and points rearward. Second guide member  37  acts as a guard on cutting edge  34  and is used to cut a single flute wall for hinging or bending corrugated sheets. A guiding edge  38  is shown as an integral part of handle  31 . When blade shank  32  is attached to handle  31 , edge  38  is parallel to guide member  37  and spaced from guide member  37  an amount that would leave a cutting gap slightly larger than a wall thickness of a corrugated material to be cut. Detachable blade shank  32  has an attaching hole  391 . When attached, the base of blade shank  391  would go into a slot  390  in handle  31 . A attaching hole  392  in handle  31  would line up with blade shank attaching hole  391  and a fastener, not shown would be used to attach blade shank  32  to handle  31 . 
       FIG. 4A  shows a cutting head  40  for a blade shank consisting of a blade shank  41 , guide members  42  and  43 , staggered cutting edges  44  and  45 , fasteners  46 , slot  48  in blade shank  41  and fastener  49 . Guide member  42  can pivot around fastener  46  and is limited in it&#39;s travel by fastener  49  in slot  48  of blade shank  41 . This pivoting action of guide member  42  expands the critical angle range between the handle and the guide member needed to keep the guide member from binding in the flute of a corrugated sheet while cutting. 
       FIG. 4B  shows a second embodiment of the cutting head  40  where slot  48  and fastener  49  swap positions with fastener  46  of guide member  42 . 
       FIG. 5  shows a cutting head  50  for a blade shank consisting of a blade shank  51 , guide members  52  and  53 , staggered cutting edges  54  and  55 , fasteners  56 , and alternate positioning holes  57  in blade shank  51 . Guide member  52  and  53  can be repositioned on blade shank  51  by removing fasteners  56 , repositioning the guide member over a different pair of alternate positioning holes  57 , and reattaching the guide member with fasteners  56 . This repositioning of the guide member creates a new cutting contact point on cutting edges  54  and  55 , effectively replacing the cutting surface. 
       FIG. 6  shows an exploded side view of a blade shank  60  consisting of a blade shank  61 , a replaceable guide member  64 , a smaller replaceable guide member  63 , a straight angled cutting edge  62 , fasteners  65 , mounting holes  62  of blade shank  61 , guide member mounting holes  66  of guide member  64 , guide member mounting holes  67  of guide member  63 , a cutting edge  69  of blade shank  61 .  FIG. 6A  shows a front view of guide member  63  showing slot  68 . In operation, either guide member would insert blade shank  61  in guide member slot  68  so that guide member holes  66  or  67  line up with blade shank holes  62  so that the guide member is projecting over the cutting edge  69 . Fasteners  65  attach either guide member  63  or  64  to blade shank  61  through holes  62 . When attached, the guide member would point rearward extending past angled cutting edge  69 . Since cutting edge  69  is angled to guide member  63  or  64 , staggered cutting points of contact on cutting edge  69  are created. 
       FIG. 7  shows a blade shank  70  that can include a handle  71 . The handle  71  is attached to a blade base  72  such that the blade base extends from the forward end of handle  71 . Blade base  71  is notched to allow for a replaceable cutting blade  75 . The rearward edge side of the cutting blade  75  has been ground to create a sharp edge. A first guide member,  73 , extends beyond blade base  72  and cutting blade  75 , rearward and is positioned over cutting blade  75  so there are parts of the cutting blade on either side of guide member  73 . A second guide member  74  is attached to the edge of blade base  72  and cutting blade  75  and creates a guard for the cutting blade. Guide member  73  and  74  can be made from metal or plastic. Fastening holes  780  in cutting blade  75  and hole  77  in second guide member  74  are aligned and fasteners  76  are used to attach guide member  73  and  74  to blade base  72  and attach cutting blade  75  to second guide member  74 . A top front view is provided showing a slot  78  in guide member  74 . In slot  78 , the position of blade shank  72  and cutting blade  75  can be seen. 
     The blade shank of  FIG. 8  is similar to the blade shank of  FIG. 7  with the addition of a guiding edge  89 .  FIG. 8  shows a flute knife  80  that includes a handle  81 . The handle  81  is attached to a blade base  82  such that the blade base extends from the forward end of handle  81 . Blade base  81  is formed to allow for a replaceable cutting blade  85 . Each rearward edge side of the cutting blade has been ground to create a sharp edge. A first guide member,  83 , extends beyond blade base  82  and cutting blade  85  rearward, and is positioned over cutting blade  85  so there are parts of the cutting blade on either side of guide member  83 . A second guide member  84  is attached to the edge of blade base  82  and cutting blade  85  and creates a guard for the cutting blade. Guide member  83  and  84  can be made from metal or plastic. Fastening holes  880  in cutting blade  85  and hole  87  in second guide member  84  are aligned and fasteners  86  are used to attach guide member  83 ,  84  to blade base  82 . Fastener  87  is used to attach cutting blade  85  to second guide member  84 . Guide edge  89  can be made as an extension of handle  81  or of blade base  82 . It extends beyond the forward and rearward ends of guide member  83 , runs parallel with guide member  83  and is spaced from guide member  83  a distance that is slightly more than a wall thickness of the corrugated sheet to be cut. Guide edge  89  helps align the non rigid corrugated sheet with guide member  83  to prevent binding of guide member  83  when cutting. A top front view is provided showing a slot  88  in guide member  84  and guide edge  89  below. In slot  88 , the position of blade shank  82  and cutting blade  85  can be seen. 
       FIG. 9A  shows a blade base  91  that is formed to allow for a replaceable cutting blade  95  with a cutting edge that has staggered cutting points on a constant angled blade. Each rearward side of the cutting blade has been ground to create a sharp edge. A first guide member,  93 , extends beyond blade base  92  and cutting blade  95 , rearward and is positioned over cutting blade  95  so there are parts of the cutting blade on either side of guide member  93 . A second guide member  94  is attached to the edge of blade base  92  and cutting blade  95  and creates a guard for the cutting blade. Guide member  93  and  94  can be made from metal or plastic. Fastening holes  980  in cutting blade  95  and hole  97  in second guide member  94  are aligned and a fastener (not shown) is used to attach member  94  and blade  95 . Fasteners  96  are used to attach guide member  93 ,  94  to blade base  92 . A second hole  980  is shown to illustrate that cutting blade  95  is reversible. A notch  99  on blade base  92  is shown and is a second holding point for cutting blade  95 . 
       FIG. 9B  shows a blade shank  90 . Blade base  91  is formed to allow for a replaceable cutting blade  95  with a cutting edge that has staggered cutting points on a double angled blade. Each rearward edge side of the cutting blade have been ground to create a sharp edge. A first guide member,  93 , extends beyond blade base  92  and cutting blade  95  rearward and is positioned over cutting blade  95  so there are parts of the cutting blade on either side of guide member  93 . A second guide member  94  is attached to the edge of blade base  92  and cutting blade  95  and creates a guard for the cutting blade. Guide member  93  and  94  can be made from metal or plastic. Fastening holes  980  in cutting blade  95  and hole  97  in second guide member  94  are aligned and fasteners  96  are used to attach guide member  93 ,  94  to blade base  92  and attach cutting blade  95  to second guide member  94 . A second hole  980  is shown to illustrate that cutting blade  95  is reversible. A notch  99  on blade base  92  is shown and is a second holding point for cutting blade  95 . A top front view is provided showing a slot  98  in guide member  94 . In slot  98 , the position of blade shank  92  and cutting blade  95  can be seen. 
     The blade shank of  FIG. 10  is similar to the blade shank of  FIG. 7  with a pivoting first guide member  103 .  FIG. 10  shows a flute knife  100  that can include a handle  101 . The handle  101  is attached to a blade base  102  such that the blade base extends from the forward end of handle  101 . Blade base  101  is formed to allow for a replaceable cutting blade  105 . The rearward edge side of cutting blade  105  has been ground to create a sharp edge and the cutting blade has a constant angle to a first guide member,  103 . Guide member  103  extends beyond blade base  102  and cutting blade  105 , rearward and is positioned over cutting blade  105  so there are parts of the blade on either side of guide member  103 . A second guide member  104  is attached to the edge of blade base  102  and cutting blade  105  and creates a guard for the cutting blade. Guide member  103  and  104  can be made from metal or plastic. Fasten  107  in second guide member  104  is used to hold cutting blade  105  in place. Blade base  102  is slotted with a crescent shaped slot  108  at the rear of guide member  103 . Fastener  109  runs through guide member  103  and slot  108  allowing the end of guide member  103  to pivot toward and away from guide member  104  and around guide member fastener  106  of guide member  103 . This pivoting action helps keep guide member  103  aligned in a flute of a corrugated sheet even if the handle angle is slightly off. 
     A top front view is provided showing a guide member  104  and the positions of blade shank  102  and cutting blade  105  can be seen. 
     The blade shank of  FIG. 11  is similar to the blade shank of  FIG. 7  with the addition of a guide member reposition system.  FIG. 11  shows a flute knife  1100  that can include a handle  1101 . The handle  1101  is attached to a blade base  1102  such that the blade base extends from the forward end of handle  1101 . Blade base  1102  is formed to allow for a replaceable cutting blade  1105 . Each rearward edge side of the cutting blade has been ground to create a sharp edge. A first guide member,  1103 , extends beyond blade base  1102  and cutting blade  1105 , rearward and is positioned over cutting blade  1105  so there are parts of the cutting blade on either side of guide member  1103 . A second guide member  1104  is attached to the edge of blade base  112  and cutting blade  115  and creates a guard for the cutting blade. Guide member  1103  and  1104  can be made from metal or plastic. Blade base  1102  has guide member repositioning holes  1107 . Guide members use fasteners  1106  to attach to blade base  1102 . Whenever a guide member is repositioned, a new sharp cutting point is created increasing the life of cutting blade  1105 . 
       FIG. 12A  is a front view of a cutting head  1200  that can be used for cutting corrugated plastic sheets consisting of a blade shank  1202  and a guide member  1204 . Guide member  1204  can be made of plastic or metal material and can be attached to blade shank  1202  by fasteners or by injected molding. Blade shank  1202  is partially encased in guide member  1204  at an angular axis, instead of at a 90 degree axis. Blade shank  1202  has an extended side  1205  that can be used for holding or as an attaching point for a handle. Guide member  1204  is of such a cross section as to be just smaller than the flute hole of a corrugated sheet it is to be used with. When guide member  1204  is inserted into a flute of a corrugated sheet, it guides blade shank  1202  through the sheet at a bevel angle to the sheet so the sheet walls are cut at the same bevel angle as the bevel angle of blade shank  1202  in guide member  1204 . 
       FIG. 12B  shows a side perspective angle of cutting head  1200 . A cutting edge  1201  is shown at the bottom of blade shank  1202 . This cutting edge can be ground or sharpened so it is sharp enough to slice through the corrugate sheet. 
       FIG. 13  is similar to  FIG. 12  with the addition of a bend in blade shank  1302  creating a handle section,  1305 , to maintain a 90 degree angle to the sheet while cutting.  FIG. 13  is a front view of a cutting head  1300  that can be used for cutting corrugated plastic sheets consisting of a blade shank  1302  and a guide member  1304 . Guide member  1304  can be made of plastic or metal material and can be attached to blade shank  1302  by fasteners or by injected molding. Blade shank  1302  is partially encased in guide member  1304  at an angular axis instead of at a 90 degree axis. Blade shank  1302  has a bend outside the guide member forming side  1305 . Side  1305  can be used for holding or as an attaching point for a handle. Blade shank side  1305  forms a 90 degree angle to the guide member. Guide member  1304  is of such a cross section as to be just smaller than the flute hole of a corrugated sheet it is to be used with. When guide member  1304  is inserted into a flute of a corrugated sheet, it guides blade shank  1302  through the sheet and at a bevel angle to the sheet so the sheet walls are cut at the same bevel angle as the bevel angle of blade shank  1302  in guide member  1304 . 
       FIG. 14  is similar to  FIG. 13  with the addition of a bend in a section of blade shank  1402  that is encased by guide member  1404 , creating sides  1406  and  1407 .  FIG. 14  is a front view of a cutting head  1400  that can be used for cutting corrugated plastic sheets consisting of a blade shank  1402  and a guide member  1404 . Guide member  1404  can be made of plastic or metal material and can be attached to blade shank  1402  by fasteners or by injected molding. Blade shank  1402  has two sides  1406  and  1407 , encased in guide member  1404 . Sides  1406  and  1407  are at an angular axis to the sides of guide member  1404  instead of at a 90 degree axis creating a opposite angled bevel angle on either side of guide member  1404 . Blade shank  1402  has a bend outside the guide member forming side  1405 . Side  1405  can be used for holding or as an attaching point for a handle. Blade shank side  1405  forms a 90 degree angle to the guide member. Guide member  1404  is of such a cross section as to be just smaller than the flute hole of a corrugated sheet it is to be used with. When guide member  1404  is inserted into a flute of a corrugated sheet, it cuts with blade shank sides  1406  and  1407  at a bevel angle so the sheet walls are cut at an opposing bevel angle of its outer wall sides. 
       FIG. 15  is similar to  FIG. 14  with the addition of a bend in a section of blade shank  1502  that is encased by guide member  1502 , creating side  1508  and the addition of a second guide member at the end of blade shank  1502 .  FIG. 15  is a front view of a cutting head  1500  that can be used for cutting corrugated plastic sheets consisting of a blade shank  1502  and a first guide member  1504 . First guide member  1504  can be made of plastic or metal material and can be attached to blade shank  1502  by fasteners or by injected molding. A second guide member,  1509 , is attached at the end of blade shank  1502  on side  1507 . Guide member  1509  runs parallel to guide member  1504 , acts as a guard to side  1507 , is made out of the same material and attached in the same manner as guide member  1504 . Blade shank  1502  has a side  1508 , encased in guide member  1504  and is perpendicular to the top and bottom sides of guide member  1504 . Sides  1506  and  1507  join with side  1508  and are at opposing angles to side  1508 . Blade shank  1502  has a bend outside guide member  1504  forming side  1505 . Side  1505  can be used for holding or as an attaching point for a handle. Blade shank side  1505  forms a 90 degree angle to its side of guide member  1504 . Guide member  1504  and  1509  are of such a cross section as to be just smaller than the flute hole of a corrugated sheet it is to be used with. When guide member  1504  is inserted into a flute of a corrugated sheet, the blade shank sides  1506  and  1507  cut through the sheet at beveled angles to the sheet so the sheet walls are cut at opposed bevel angles. 
       FIG. 16  is a side view of a cutting head  1600  similar to the one in  FIG. 15  with an addition of a bend to form side  1610  at the end of side  1607 . Side  1610  is parallel with side. This side view shows cutting sides  1606  and  1607  have staggered cutting edges because of their angle to guide members  1604  and  1609 . This staggering of the cutting edges on either side of guide member  1604  makes the initial blade entry into a corrugated sheet easier because one side is entering the sheet at a time as opposed to both sides at the same time.  FIG. 16  shows fasteners  1611  used to attach guide members  1604  and  1609  to blade shank  1602 . 
       FIG. 17  is a front view of an embodiment a cutting head  1700  that would have independent sides to each guide member. Independent side  1712  and  1713  are held to blade shank  1702  with fasteners  1711 . 
       FIG. 18  A is a front view of a cutting head  1800  showing the different height and width of guide member sides  1812  and  1813  on cutting head  1800 . Blade shank  1802  is made up of sides  1805 ,  1806 ,  1807 ,  1808  and  1810 . Guide member  1804  is made up of guide member sides  1813  and  1812  and blade shank side  1808  held together by fastener  1811  (not shown). Guide member  1809  is made up of guide member sides  1813  and  1812  and blade shank side  1810  held together by fastener  1811  (shown by dashed lines). By varying the height and width of guide member sides  1812  and  1813  or by varying the angle of sides  1806  and  1807  to side  1808  and  1810 , a cut in a specific place on the outer top and bottom walls of a corrugated sheet can be made. For instance, a specific cutting location in the center of the top and bottom flute walls or a cutting location at the top and bottom flute walls next to an inner side flute wall can be designed. 
       FIG. 18B  is an exploded view of  FIG. 18A  showing parts of cutting head  1800  including fasteners  1811 . 
       FIG. 19  is a view looking down the guide member  1904  of cutting head  1900  inside a flute of a corrugated sheet  1914  during a cut. Guide member  1904  is made up of guide member sides  1913  and  1912  and blade shank side  1908 . Cutting edges  1906  and  1907  cut sheet  1914  so that flute wall sections  1915  is pushed inward toward guide member side  1912  and flute wall section  1916  is pushed outward creating a non-pinching slice for cutting edges  1906  and  1907 . 
       FIG. 20  shows a view down guide member  1804  of cutting head  1800  while in a corrugated sheet including a handle  2001  attached to part  1805  of cutting head  1800 .