CA1064390A - Compound angle cutting edge and method of using same - Google Patents
Compound angle cutting edge and method of using sameInfo
- Publication number
- CA1064390A CA1064390A CA298,780A CA298780A CA1064390A CA 1064390 A CA1064390 A CA 1064390A CA 298780 A CA298780 A CA 298780A CA 1064390 A CA1064390 A CA 1064390A
- Authority
- CA
- Canada
- Prior art keywords
- cutting
- stock material
- piercing
- die
- cutting edges
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A novel compound angle cutting edge configuration on a die rule provides cleaner cuts on stock material with less tonnage, improved cutting and cleaner cuts. The die rule cutting edge includes a plurality of side by side notches on only one side of the cutting edge defining a plurality of equally spaced piercing points. A primary cutting edge extends from each piercing point substantially to a next adjacent piercing point and forms a compound angle with an imaginary line through the tips of the piercing points of between about one and fifteen degrees. In a method of cutting blanks, the cutting edges are axially pressed through stock material to cut blanks of predetermined configuration. The cutting action consists of the piercing points penetrating the material and then the primary cutting edges slicing the stock material from one penetration point, substantially linearly and unidirectionally, to the next adjacent penetration point.
A novel compound angle cutting edge configuration on a die rule provides cleaner cuts on stock material with less tonnage, improved cutting and cleaner cuts. The die rule cutting edge includes a plurality of side by side notches on only one side of the cutting edge defining a plurality of equally spaced piercing points. A primary cutting edge extends from each piercing point substantially to a next adjacent piercing point and forms a compound angle with an imaginary line through the tips of the piercing points of between about one and fifteen degrees. In a method of cutting blanks, the cutting edges are axially pressed through stock material to cut blanks of predetermined configuration. The cutting action consists of the piercing points penetrating the material and then the primary cutting edges slicing the stock material from one penetration point, substantially linearly and unidirectionally, to the next adjacent penetration point.
Description
~064390 The present invention relates generally to die rules and methods of cutting blanks.
Several unsolved problems have existed in the art of cutting devices prior to the present invention. For example, many cutting devices have somewhat elaborate cutting configur-ations which are costly to form on the cutting blade. Many other cutting blade arrangements simply do not give a clean cut on the stock material as desired.
- Still other problems arise in connection with a cutting die press. For example, many of the prior art cutting -blades require a relatively high tonnage or force to press the cutting blade entirely through the stock material. In die presses where a resilient die pad is used, inordinate wear of -~ the die pad has been experienced with various types of notched blades because of the cutting blade cutting away the die pad after it has sliced through the stock material. If a hard , ~; metallic back up die pad is used, the cutting blade is dulled . ... .
by metal-to-metal contact after the cutting operation.
- Specific examples of prior art cutting blade configur-ations are disclosed in United States Patents Nos. 3,277,764 to Henc, 3,422,712 to Lovas, and 201,104 to Frary. Each of these :
`'; prior art devices likewise include inherent disadvantages not experienced by the present invention.
According to the present invention there is provided an `~ improved die rule having a plurality of generally equally spaced piercing points and primary cutting edges on a chamfered cutting portion of the cutting edges being substantially linear and extending from one piercing point substantially the entire distance to a next adjacent piercing point, each cutting edge ` 30 and a line through the tips of the piercing points defining an ;;
;, 1 ' A.
.~
10643gO
acute angle between about one and five degrees in side elevation of the die rule, the piercing points and cutting edges being defined by notches formed in the die rule chamfer, the notches being defined by major and minor triangular-shaped notch faces between adjacent piercing points, the major triangular face being bounded on one edge by a primary cutting edge, the notch faces having a common side, and the minor triangular face defining a secondary edge interconnecting the primary cutting edge with a next adjacent piercing point, the primary cutting edge and secondary edge defining a generally check-marked shaped edge configuration between each pair of adjacent piercing ; points.
The invention also provides a method of cutting blanks -:
from stock material comprising the steps of positioning the stock material in alignment with a die rule, relatively moving the die rule and stock material toward one another, initially contacting the stock material by a plurality of generally equally spaced peaks on a cutting portion of the die rule, thereby piercing the stock material at a plurality of generally equally spaced positions, continuing to relatively move the material and the die rule and cutting the stock material between the plurality of pierced positions with a plurality of primary cutting edges, each of the primary cutting edges (a) extending from one piercing peak substantially the entire distance to the next piercing peak and (b) extending away from . the stock material by an angle of from about one to fifteen degrees with a line connecting the piercing peaks, the cutting edges thereby progressively cutting the stock material substan-tially unidirectionally from one pierced position progressively toward a next adjacent pierced position, preferably at a rate : ~ -2- ~:
.
10643~0 -in comparison with the rate of relative movement between the cutting tool and stock material within the ratios of between about 57.29:1 and 3.73:1.
Another particular aspect of the method of the invention provides in a method of cutting stock material the steps of positioning the stock material on a resilient die pad in alignment with a cutting die rule, the die rule having a chamfered portion defined by two converging surfaces which intersect to form a cutting portion, the cutting portion having formed thereon a plurality of notches which define a plurality . :
of generally equally spaces piercing points and a plurality of substantially linear primary cutting edges extending from each -piercing point substantially the entire distance to an adjacent piercing point, the primary cutting edges extending away from the piercing points by an angle of no more than fifteen degrees, - :
thereby forming a valley on the cutting portion between each piercing point, the valley having a depth of no more than three ...
; sixteenths of an inch; relatively moving the stock material and the die rule toward one another, and in a substantially simultaneous, sequential operation (a) initially penetrating the stock material at a plurality of positions with the die ., ;' rule piercing points, (b) cutting the stock material with the :
primary cutting edges in a direction away from each initially penetrated position toward a next adjacent penetrated position, whereby the stock material from each penetrated position is cut substantially the entire distance therebetween in a progressive cutting action in substantially only one direction at a rate of greater than 3.73 times the rate of relative movement between the stock material and the die rule, due to the angle of the ~I
' 30 primary cutting edges, and (c~ pressing the piercing points , ~; 3 ~064.3~o through the stock material and into the resilient die pad by a distance of not more than about three sixteenths of an inch due to the shallow valley depth on the cutting portion, at which depth the stock material will be cut through its entire depth by the cutting edges; and retracting the stock material from the die rule and die pad.
A further particular aspect of the method of the in- ~
vention provides in a method of cutting blanks from stock : :
material, the steps of positioning the stock material in align-ment with a cutting tool having a pair of converging faces; and relatively moving the cutting tool and stock material toward one another (a) to initially pierce the stock material in a plurality ; of generally equally spaced positions by a plurality of generally equally spaced peaks on a cutting portion of the cutting tool, and thqreafter (b) to progressively cut the stock material sub-stantially unidirectionally from each of the pierced positions toward a next adjacent pierced position with a plurality of primary cutting edges on the cutting tool, each of the primary cutting edges extending from one piercing peak substantially the entire distance to the next piercing peak and extending away from the stock material by an angle of from about 1 to 5 with , a line connecting the piercing peaks and (c) to cut the stock material between the pierced positions at a rate of between about 11.43 and 57.29 times the rate of relative movement between the cutting tool and stock material.
When a cutting die rule is used in combination with a resilient back up die pad underneath the stock material, the piercing points and cutting edges must extend completely through the stock material and into the die pad for a depth which is at least equal to the depth of the notch valley between the , .~ :
piercing points. Since the present invention enables - a relatively shallow notch valley depth, the penetration into the die pad is reduced, resulting in increased die pad life.
The present invention may be used quite satis- :
factorily to cut a wide range of materials, including for example, fiberglass, fabrics, foam rubber, paper, surgical pads, sheet material including vinyl fibers, aluminum, plastics, and various and numerous types of textile goods. This extreme wide-range utility of the . .
present invention can therefore be appreciated.
Many advantages have also been found to follow from the present invention. First, less tonnage or ~-~
pressure is required to press the cutting tool or die rule through the stock material. This enables smaller power means with an associated reduction in cost. Ad-ditionally, the lower tonnage requirement results in longer life of the cutting tool, increased production, less maintenance and machine down time is obtained, since reduced pressure is developed at the cutting edge.
Another advantage is the cleaner, straighter .,j, , .
; cuts that are accomplished by the present invention.
Additionally, the notched compound cutting edge con-figuration is relatively simple to form and can be done, ' ,,7 for example, by grinding. As previously discussed, another advantage afforded by the present invention is longevity of the back up cutting die pad.
. Other advantages are particular to the in-dividual stock material being cut. For example, in 30 cutting fiberglass it has been found that approximately `''., ' '.
,~ . , . :. . . . .... : - i , ~ , , 106~3~?0 eighty percent less dust is generated during cuttingy Fibers in vinyl and other fiber materials are not fused together, because of less heat generated during the cut-ting ac~ion, resulting from cleaner cutting while the reduced pressure is exerted on the cutting tool.
Cutting cylindrical holes in foam with prior art cutting instruments generally results in a concave-shaped cut along the thickness of the stock material.
This is due to the cutting instrument compressing the foam material before the cutting action actually begins.
The present invention eliminates the concave or convex holes or end cuts and proves a straighter cut for foam materials because the piercing points initiate the cut-ting action and reduces the foam compression.
Other advantages and meritorious features of this invention will more fully appear from the follow-ing specification, claims and accompanying drawings.
The embodiment of the invention will now be described with reference to the accompanying drawings in which:
Figure 1 is a schematic, cross-sectional view of a die press;
Figure 2 is a perspective view of the cutting -` tool of Figure l;
Figure 3 is a schematic, partially cross-sectional view of another die press and cutting tool in combination with a punch tool;
Figure 4 is a perspective view of the cutting tool of Figure 3;
. ~Y ..
Figures 5-10 are perspective views of various :, :
, - 6 -10~;43g~ -cutting tools;
Figure 11 i5 an enlarged, fragmented plan view of one embodiment of the cutting edge configuration;
Figure 12 is an enlarged, fragmented side elevational view of the cutting edge configuration of Figure 11;
Figure 13 is a cross-sectional view taken along plane 13-13 of Figure 12.
Referring to the drawings, Figure 1 illustrates a cutting press 10 which is primarily suited for use in cutting thick or tough materials, such as soft metallic materials.
The die press 10 includes a fixed die base 12 surmounted by and connected to mounting plate 14 in a conventional manner.
A male punch 16 and a resilient stripper pad 18 are suitably mounted on top of mounting plate 14 for receiving stock material 20. The stock material is cut with a flat die rule 22 which is shown in perspective in Figure 2. The cutting edge of die rule 22 includes a plurality of side-by-side notched configurations 23 which form a novel cutting edge that will be more fully explained below.
Die rule 22 is mounted in a die rule mounting block 24, which is illustrated as being a wood block. Mounting block 24 is suitably mounted to a back up plate 26 which is connected to a punch holder 28. A compressible stripper pad 30 is also attached to mounting block 24 in conventional manner and comprises, for example, hard rubber as is somewhat ' conventional in the art. The die rule 22, stripper pad 30, , mounting block 24, back up plate 26, and punch holder 28 comprise a vertically reciprocal cutting die.
Operation of the embodiment of Figure 1 includes -~ . . , , ~ . ~ - - .
10~439~
raisin~ the cutting die so that a piece of stock material 20 may be properly positioned on male punch 16 and stripper pad 18.
The cutter die is then driven under pressure downwardly so that the die blade 22 severs the stock material to ~orm a blank of predesired configuration, thereby leaving scrap material 33.
As illustrated, die rule blade 22 cuts through the stock material and barely extends into a slot 32 defined between punch 16 and stripper pad 18. Downward movement of the die press is limited substantially to the position shown in Figure 1, so that the cutting edge on rule 23 does not strike mounting plate 14. As the die rule blade 22 projects into slot 32, the stripper pad 30 is compressed. Then as the die press is raised, stripper pad 30 expands and leaves the cut stock material on punch 16.
Figure 3 illustrates a die press primarily suited for cutting soft stock material. This embodiment includes a fixed base 42 and a vertically reciprocable punch holder 44 to which back up plate 46, mounting block 48, and die rule blade 50 are ; mounted. In this particular embodiment, the die rule blade is cylindrical as shown in Figure 4 and includes a plurality of side-by-side notches 52 in accordance with the present inven-tion. Also in this embodiment, a punch 54 is suitably mounted in mounting block 48, and may include the cutting edge config-uration of this invention.
In operation of the embodiment in Figure 3, the punch ; holder 44 is raised from the position illustrated and a piece of stock material 56 is properly positioned on a resilient die pad 58. Die pad 58 is suitably mounted on the fixed base 42 and is comprised of a rubber or polyurethane material. Scrap material is formed during the cutting operation by punch 54, ,, ;' . . ...... , . . ................. ;, . . . . .
: - . . . : . . ... . . . .
~06439a the scrap being removed through a knock-out hole 60 in punch 54, as is conventional.
After the stock material is properly positioned on the die pad, punch 54 is moved under pressure by suitable power means, such as a hydraulic cylinder and piston, to drive the die rule cutting blade through the stock material 56. At about the same time, punch 54 forms a scrap slug.
As shown in Figure 3, the die rule cutting edge barely cuts into the die pad. This is necessary so that the notched configuration of the cutting edge in the present invention will completely cut through the stock material. However, in later ; portions of this disclosure, it will be explained that the present invention limits the extent to which the die rule cuts into the die pad, thereby yielding one of the advantages of the :- .
present invention; i.e., greater die pad longevity, with very ``~ little resurfacing required.
From the embodiments shown in Figures 1 and 3, it can be readlly seen that the cutting edge configuration of this invention can be used in a variety of ways. Figures 5-10 further illustrate that the cutting edge configuration is not limited to a die rule, per se, but is virtually unlimited in its application. For example, Figure 5 illustrates a circular hole saw 70 having a shaft 71 and being conventional in every aspect except the novel cutting edge configuration 72 of the present invention.
Figure 6 illustrates a flat die rule blade similar to that of Figure 2 and including a shank 74. A chamfer 75 at the cutting edge of the die rule is formed by two conver-ging, generally V-shaped surfaces. The novel cutting edge con-figuration of this invention is formed on the chamfer 75 and .~
, , ;, _ ~ _ . , . ~
.~064390 includes the plurality of notches and side-by-side peaks 76.
Figures 7 and 8 illustrate cylindrical die rules, or punches, 78 and 82 having respective chamfer regions 79 and 83.
In these embodiments, the internal bore of the die rule is generally cylindrical, but there still existC two converging surfaces to define the cutting edge. Notches 80 and 8~ are ` formed on the terminus of the cylindrical die rules to define the cutting edge configuration of this invention. Each punch includes a knockout hole 77 and 85, respectively, for scrap materi~l ejection.
Figure 9 illustrates a slitter wheel 86 including a circular hole 87 and being conventional in every respect except for the cutting edge configuration 88 of the present invention.
As is known to those who are skilled in the cutting art, a slitter wheel traverses stock material under pressure to effect the cutting operation.
Figure 10 illustrates another version of a cylindrical die rule 90 which is substantially similar to die rule 50 illus-trated in Figure 4. Of course, the cutting edge configuration 92 is that of the present invention.
Figures 11-13 show in enlarged fashion a cutting ;~ edge configuration according to a preferred embodiment of the ;; ~ the present inven-tion. From Figure 11, it can be seen that the illustrated tool is a cylindrical die rule 100, similar to that in Figure 10. The die rule 100 includes a shank 102 and a chamfer formed by converging surfaces 104 and 106. Figure 13 shows the converging sides forming an angle C, which in preferred embodiment, should be chosen to fall in the range of between one and thirty degrees. As discussed pre-` 30 viously in regard to Figures7 and 8, surface 104 could be cylin-';' _ 10 ~:; A -~
. ~
drical, but there would still exist two converging surfaces to define the die rule cutting region.
The cutting edge configuration includes side-by-side notches or indentations which are formed on only one of the chamfer converging surfaces, for example, by grinding.
rhese notches define a plurality of teeth having generally equally spaced peaks 108 which serve to pierce the stock material to initiate the cutting action. The notches are also configured to form a plurality of primary cutting or slicing edges 110, each extending away from one peak into an associated notch and toward a next adjacent peak. It can be seen from Figure 12, that cutting blade edge 110 extends approx-imately 75 to 80 percent or more of the distance between two adjacent peaks. For purposes of defining the present invention, it is considered that this constitutes the primary cutting edge extending substantially across the entire distance between two adjacent peaks.
, Further, it can be seen from Figure 12 that the primary cutting edge 110 forms an angle "b" with a line through piercing points 108. According to the invention, this angle ` should be no more than about fifteen degrees. More preferably, the angle should be within the range of between about one and :. ~., ` five degrees.
Figure 11 also shows that cutting edge 110 forms an angle "a" in plan view with a line through peaks 108. This ., ~ . .
~ angle is directly related, in general, to the slope angle of . .
~; surface 104 relative to the vertical. This relationship can be seen in Figure 13j wherein the notch is illustrated in : ...
` phantom. In most instances, this angle "a" will be between about one and fifteen degrees, but this is not critical. In ...
. ~
die rule embodiments having a cylindrical inner bore, such as in Figures 7 and 8, angle "a" would appear to approach zero for strict geometrical reasons.
The notched configuration of the present invention also defines a pair of pyramidal notch surfaces 112 and 114 and an incidentally-occurring secondary cutting edge 116. The secondary cutting edge, of course, cuts only small portions of the stock material so that the cutting action is subs~antially unidirectionally along primary cutting edge 110 from one piercing point to the next. In some embodiments, edge 116 may even become purely vertical so that the entire cutting action is along a primary cutting edge 110. For definitional purposes, surfaces 110 and 11~ are considered to constitute a check-marked shaped edge interconnecting adjacent piercing points.
Pyramidal-shaped surface 112, the major pyramidal surface, is bounded on one side by primary cutting edge 110 and has a common side with secondary pyramidal surface 114. For definitional purposes, these surfaces are considered to define a generally boomerang-shaped notch configuration. However, it is not necessary that the notches be defined by these pyramidal surfaces. The important consideration would appear to be the ` combination of the piercing points, the major cutting edges establishing progressive angular cutting from one piercing point to the next, and the notches being formed on only one side of the chamfer.
Figure 12 also illustrates that the small angle "b"
defines a relatively shallow valley depth "d". This depth will, :, of course, be a direct result of the angle "h" and the distance between adjacent piercing points. For most applications of the present invention, this depth will not be more than about three ,' :' ~ - 12 "?
.-- . .
sixteenths (3/16) of an inch. In the more preferred embodiments, the depth of the valley will be no more than about 3/32, and may even be as shallow as 1/32 and 1/64 of an inch, depending upon the material to be cut. In the most preferred embodiment, the valley depth will result from angle "b" being from about 1 to 5. It will be recalled from the discussion relating to the embodiment of Figure 3 that this shallow valley depth has great significance when a resilient back up die pad supports the stock material. Specifically, for a notched die rule blade to com-pletely cut through stock material the cutting edge portion must project completely through the stock material and therefore into the resilient die pad material. This penetration depth is mini-mized in the present invention because of the shallow notch valley depth. Accordingly, the resilient die pad does not ex-perience the wear associated with prior art notched cutting edges.
The manner of using a cutting tool having the present cutting edge configuration is substantially identical to that of prior cutting tools. However, the cutting action created by :
the present invention is not the same as in the prior art.
Specifically, when the cutting tool is pressed into the stock material peaks 108 pierce the material to initiate the cutting . action. Continued movement of the cutting tool through the ` stock material results in a progressive cutting or slicing by the primary cutting edge substantially unidirectionally from one piercing point to the next. Further, the piercing points , . .~.
~ and primary cutting edges are formed by a notch which is only . . ..
- on one side of the cutting tool so that stock material exerts a resistive pressure substantially on only one side of the cutting , :,, tool which creates a unidirectional cutting pressure on the .
; - 13 -, ,;
, . ,~ .
., ,` ~ , .. . , , . . .,.- . -~06~;~9~
material being cut. These overall structural limitations and cutting method steps result in the reduced tonnage requirements previously explained.
It will be understood from the foregoing description that the rate of cutting action in the direction between the pierced points on the stock material will be dependent upon the angle of the cutting edges. Specifically, the cotangent for a one degree cutting edge is 57.29, the cotangent for a five degree cutting edge is 11.43 and the cotangent for a fifteen degree cutting edge is 3.73. Therefore, with a one degree cutting edge, the stock material will be cut at a rate of about 57.29 times the rate of relative movement between the cutting tool and stock material; with a five degree cutting edge, the stock material between the pierced positions will be cut at a rate of about 11.43 times the rate of relative movement between the cutting tool and stock material; and with a fifteen degree cutting edge, the stock material between the pierced positions will be cut by a rate in comparison with the rate of relative movement between the cutting tool and stock material of about 3.73:1.
It is to be understood that the description and explana-tion herein is merely exemplary of the overall invention and is not intended to be limiting in any respect. For example, the cutting edge configuration may be formed by other methods than grinding and may be used in all equivalent cutting tools.
- ~ , .
~' ... . . . . .. .
,, -
Several unsolved problems have existed in the art of cutting devices prior to the present invention. For example, many cutting devices have somewhat elaborate cutting configur-ations which are costly to form on the cutting blade. Many other cutting blade arrangements simply do not give a clean cut on the stock material as desired.
- Still other problems arise in connection with a cutting die press. For example, many of the prior art cutting -blades require a relatively high tonnage or force to press the cutting blade entirely through the stock material. In die presses where a resilient die pad is used, inordinate wear of -~ the die pad has been experienced with various types of notched blades because of the cutting blade cutting away the die pad after it has sliced through the stock material. If a hard , ~; metallic back up die pad is used, the cutting blade is dulled . ... .
by metal-to-metal contact after the cutting operation.
- Specific examples of prior art cutting blade configur-ations are disclosed in United States Patents Nos. 3,277,764 to Henc, 3,422,712 to Lovas, and 201,104 to Frary. Each of these :
`'; prior art devices likewise include inherent disadvantages not experienced by the present invention.
According to the present invention there is provided an `~ improved die rule having a plurality of generally equally spaced piercing points and primary cutting edges on a chamfered cutting portion of the cutting edges being substantially linear and extending from one piercing point substantially the entire distance to a next adjacent piercing point, each cutting edge ` 30 and a line through the tips of the piercing points defining an ;;
;, 1 ' A.
.~
10643gO
acute angle between about one and five degrees in side elevation of the die rule, the piercing points and cutting edges being defined by notches formed in the die rule chamfer, the notches being defined by major and minor triangular-shaped notch faces between adjacent piercing points, the major triangular face being bounded on one edge by a primary cutting edge, the notch faces having a common side, and the minor triangular face defining a secondary edge interconnecting the primary cutting edge with a next adjacent piercing point, the primary cutting edge and secondary edge defining a generally check-marked shaped edge configuration between each pair of adjacent piercing ; points.
The invention also provides a method of cutting blanks -:
from stock material comprising the steps of positioning the stock material in alignment with a die rule, relatively moving the die rule and stock material toward one another, initially contacting the stock material by a plurality of generally equally spaced peaks on a cutting portion of the die rule, thereby piercing the stock material at a plurality of generally equally spaced positions, continuing to relatively move the material and the die rule and cutting the stock material between the plurality of pierced positions with a plurality of primary cutting edges, each of the primary cutting edges (a) extending from one piercing peak substantially the entire distance to the next piercing peak and (b) extending away from . the stock material by an angle of from about one to fifteen degrees with a line connecting the piercing peaks, the cutting edges thereby progressively cutting the stock material substan-tially unidirectionally from one pierced position progressively toward a next adjacent pierced position, preferably at a rate : ~ -2- ~:
.
10643~0 -in comparison with the rate of relative movement between the cutting tool and stock material within the ratios of between about 57.29:1 and 3.73:1.
Another particular aspect of the method of the invention provides in a method of cutting stock material the steps of positioning the stock material on a resilient die pad in alignment with a cutting die rule, the die rule having a chamfered portion defined by two converging surfaces which intersect to form a cutting portion, the cutting portion having formed thereon a plurality of notches which define a plurality . :
of generally equally spaces piercing points and a plurality of substantially linear primary cutting edges extending from each -piercing point substantially the entire distance to an adjacent piercing point, the primary cutting edges extending away from the piercing points by an angle of no more than fifteen degrees, - :
thereby forming a valley on the cutting portion between each piercing point, the valley having a depth of no more than three ...
; sixteenths of an inch; relatively moving the stock material and the die rule toward one another, and in a substantially simultaneous, sequential operation (a) initially penetrating the stock material at a plurality of positions with the die ., ;' rule piercing points, (b) cutting the stock material with the :
primary cutting edges in a direction away from each initially penetrated position toward a next adjacent penetrated position, whereby the stock material from each penetrated position is cut substantially the entire distance therebetween in a progressive cutting action in substantially only one direction at a rate of greater than 3.73 times the rate of relative movement between the stock material and the die rule, due to the angle of the ~I
' 30 primary cutting edges, and (c~ pressing the piercing points , ~; 3 ~064.3~o through the stock material and into the resilient die pad by a distance of not more than about three sixteenths of an inch due to the shallow valley depth on the cutting portion, at which depth the stock material will be cut through its entire depth by the cutting edges; and retracting the stock material from the die rule and die pad.
A further particular aspect of the method of the in- ~
vention provides in a method of cutting blanks from stock : :
material, the steps of positioning the stock material in align-ment with a cutting tool having a pair of converging faces; and relatively moving the cutting tool and stock material toward one another (a) to initially pierce the stock material in a plurality ; of generally equally spaced positions by a plurality of generally equally spaced peaks on a cutting portion of the cutting tool, and thqreafter (b) to progressively cut the stock material sub-stantially unidirectionally from each of the pierced positions toward a next adjacent pierced position with a plurality of primary cutting edges on the cutting tool, each of the primary cutting edges extending from one piercing peak substantially the entire distance to the next piercing peak and extending away from the stock material by an angle of from about 1 to 5 with , a line connecting the piercing peaks and (c) to cut the stock material between the pierced positions at a rate of between about 11.43 and 57.29 times the rate of relative movement between the cutting tool and stock material.
When a cutting die rule is used in combination with a resilient back up die pad underneath the stock material, the piercing points and cutting edges must extend completely through the stock material and into the die pad for a depth which is at least equal to the depth of the notch valley between the , .~ :
piercing points. Since the present invention enables - a relatively shallow notch valley depth, the penetration into the die pad is reduced, resulting in increased die pad life.
The present invention may be used quite satis- :
factorily to cut a wide range of materials, including for example, fiberglass, fabrics, foam rubber, paper, surgical pads, sheet material including vinyl fibers, aluminum, plastics, and various and numerous types of textile goods. This extreme wide-range utility of the . .
present invention can therefore be appreciated.
Many advantages have also been found to follow from the present invention. First, less tonnage or ~-~
pressure is required to press the cutting tool or die rule through the stock material. This enables smaller power means with an associated reduction in cost. Ad-ditionally, the lower tonnage requirement results in longer life of the cutting tool, increased production, less maintenance and machine down time is obtained, since reduced pressure is developed at the cutting edge.
Another advantage is the cleaner, straighter .,j, , .
; cuts that are accomplished by the present invention.
Additionally, the notched compound cutting edge con-figuration is relatively simple to form and can be done, ' ,,7 for example, by grinding. As previously discussed, another advantage afforded by the present invention is longevity of the back up cutting die pad.
. Other advantages are particular to the in-dividual stock material being cut. For example, in 30 cutting fiberglass it has been found that approximately `''., ' '.
,~ . , . :. . . . .... : - i , ~ , , 106~3~?0 eighty percent less dust is generated during cuttingy Fibers in vinyl and other fiber materials are not fused together, because of less heat generated during the cut-ting ac~ion, resulting from cleaner cutting while the reduced pressure is exerted on the cutting tool.
Cutting cylindrical holes in foam with prior art cutting instruments generally results in a concave-shaped cut along the thickness of the stock material.
This is due to the cutting instrument compressing the foam material before the cutting action actually begins.
The present invention eliminates the concave or convex holes or end cuts and proves a straighter cut for foam materials because the piercing points initiate the cut-ting action and reduces the foam compression.
Other advantages and meritorious features of this invention will more fully appear from the follow-ing specification, claims and accompanying drawings.
The embodiment of the invention will now be described with reference to the accompanying drawings in which:
Figure 1 is a schematic, cross-sectional view of a die press;
Figure 2 is a perspective view of the cutting -` tool of Figure l;
Figure 3 is a schematic, partially cross-sectional view of another die press and cutting tool in combination with a punch tool;
Figure 4 is a perspective view of the cutting tool of Figure 3;
. ~Y ..
Figures 5-10 are perspective views of various :, :
, - 6 -10~;43g~ -cutting tools;
Figure 11 i5 an enlarged, fragmented plan view of one embodiment of the cutting edge configuration;
Figure 12 is an enlarged, fragmented side elevational view of the cutting edge configuration of Figure 11;
Figure 13 is a cross-sectional view taken along plane 13-13 of Figure 12.
Referring to the drawings, Figure 1 illustrates a cutting press 10 which is primarily suited for use in cutting thick or tough materials, such as soft metallic materials.
The die press 10 includes a fixed die base 12 surmounted by and connected to mounting plate 14 in a conventional manner.
A male punch 16 and a resilient stripper pad 18 are suitably mounted on top of mounting plate 14 for receiving stock material 20. The stock material is cut with a flat die rule 22 which is shown in perspective in Figure 2. The cutting edge of die rule 22 includes a plurality of side-by-side notched configurations 23 which form a novel cutting edge that will be more fully explained below.
Die rule 22 is mounted in a die rule mounting block 24, which is illustrated as being a wood block. Mounting block 24 is suitably mounted to a back up plate 26 which is connected to a punch holder 28. A compressible stripper pad 30 is also attached to mounting block 24 in conventional manner and comprises, for example, hard rubber as is somewhat ' conventional in the art. The die rule 22, stripper pad 30, , mounting block 24, back up plate 26, and punch holder 28 comprise a vertically reciprocal cutting die.
Operation of the embodiment of Figure 1 includes -~ . . , , ~ . ~ - - .
10~439~
raisin~ the cutting die so that a piece of stock material 20 may be properly positioned on male punch 16 and stripper pad 18.
The cutter die is then driven under pressure downwardly so that the die blade 22 severs the stock material to ~orm a blank of predesired configuration, thereby leaving scrap material 33.
As illustrated, die rule blade 22 cuts through the stock material and barely extends into a slot 32 defined between punch 16 and stripper pad 18. Downward movement of the die press is limited substantially to the position shown in Figure 1, so that the cutting edge on rule 23 does not strike mounting plate 14. As the die rule blade 22 projects into slot 32, the stripper pad 30 is compressed. Then as the die press is raised, stripper pad 30 expands and leaves the cut stock material on punch 16.
Figure 3 illustrates a die press primarily suited for cutting soft stock material. This embodiment includes a fixed base 42 and a vertically reciprocable punch holder 44 to which back up plate 46, mounting block 48, and die rule blade 50 are ; mounted. In this particular embodiment, the die rule blade is cylindrical as shown in Figure 4 and includes a plurality of side-by-side notches 52 in accordance with the present inven-tion. Also in this embodiment, a punch 54 is suitably mounted in mounting block 48, and may include the cutting edge config-uration of this invention.
In operation of the embodiment in Figure 3, the punch ; holder 44 is raised from the position illustrated and a piece of stock material 56 is properly positioned on a resilient die pad 58. Die pad 58 is suitably mounted on the fixed base 42 and is comprised of a rubber or polyurethane material. Scrap material is formed during the cutting operation by punch 54, ,, ;' . . ...... , . . ................. ;, . . . . .
: - . . . : . . ... . . . .
~06439a the scrap being removed through a knock-out hole 60 in punch 54, as is conventional.
After the stock material is properly positioned on the die pad, punch 54 is moved under pressure by suitable power means, such as a hydraulic cylinder and piston, to drive the die rule cutting blade through the stock material 56. At about the same time, punch 54 forms a scrap slug.
As shown in Figure 3, the die rule cutting edge barely cuts into the die pad. This is necessary so that the notched configuration of the cutting edge in the present invention will completely cut through the stock material. However, in later ; portions of this disclosure, it will be explained that the present invention limits the extent to which the die rule cuts into the die pad, thereby yielding one of the advantages of the :- .
present invention; i.e., greater die pad longevity, with very ``~ little resurfacing required.
From the embodiments shown in Figures 1 and 3, it can be readlly seen that the cutting edge configuration of this invention can be used in a variety of ways. Figures 5-10 further illustrate that the cutting edge configuration is not limited to a die rule, per se, but is virtually unlimited in its application. For example, Figure 5 illustrates a circular hole saw 70 having a shaft 71 and being conventional in every aspect except the novel cutting edge configuration 72 of the present invention.
Figure 6 illustrates a flat die rule blade similar to that of Figure 2 and including a shank 74. A chamfer 75 at the cutting edge of the die rule is formed by two conver-ging, generally V-shaped surfaces. The novel cutting edge con-figuration of this invention is formed on the chamfer 75 and .~
, , ;, _ ~ _ . , . ~
.~064390 includes the plurality of notches and side-by-side peaks 76.
Figures 7 and 8 illustrate cylindrical die rules, or punches, 78 and 82 having respective chamfer regions 79 and 83.
In these embodiments, the internal bore of the die rule is generally cylindrical, but there still existC two converging surfaces to define the cutting edge. Notches 80 and 8~ are ` formed on the terminus of the cylindrical die rules to define the cutting edge configuration of this invention. Each punch includes a knockout hole 77 and 85, respectively, for scrap materi~l ejection.
Figure 9 illustrates a slitter wheel 86 including a circular hole 87 and being conventional in every respect except for the cutting edge configuration 88 of the present invention.
As is known to those who are skilled in the cutting art, a slitter wheel traverses stock material under pressure to effect the cutting operation.
Figure 10 illustrates another version of a cylindrical die rule 90 which is substantially similar to die rule 50 illus-trated in Figure 4. Of course, the cutting edge configuration 92 is that of the present invention.
Figures 11-13 show in enlarged fashion a cutting ;~ edge configuration according to a preferred embodiment of the ;; ~ the present inven-tion. From Figure 11, it can be seen that the illustrated tool is a cylindrical die rule 100, similar to that in Figure 10. The die rule 100 includes a shank 102 and a chamfer formed by converging surfaces 104 and 106. Figure 13 shows the converging sides forming an angle C, which in preferred embodiment, should be chosen to fall in the range of between one and thirty degrees. As discussed pre-` 30 viously in regard to Figures7 and 8, surface 104 could be cylin-';' _ 10 ~:; A -~
. ~
drical, but there would still exist two converging surfaces to define the die rule cutting region.
The cutting edge configuration includes side-by-side notches or indentations which are formed on only one of the chamfer converging surfaces, for example, by grinding.
rhese notches define a plurality of teeth having generally equally spaced peaks 108 which serve to pierce the stock material to initiate the cutting action. The notches are also configured to form a plurality of primary cutting or slicing edges 110, each extending away from one peak into an associated notch and toward a next adjacent peak. It can be seen from Figure 12, that cutting blade edge 110 extends approx-imately 75 to 80 percent or more of the distance between two adjacent peaks. For purposes of defining the present invention, it is considered that this constitutes the primary cutting edge extending substantially across the entire distance between two adjacent peaks.
, Further, it can be seen from Figure 12 that the primary cutting edge 110 forms an angle "b" with a line through piercing points 108. According to the invention, this angle ` should be no more than about fifteen degrees. More preferably, the angle should be within the range of between about one and :. ~., ` five degrees.
Figure 11 also shows that cutting edge 110 forms an angle "a" in plan view with a line through peaks 108. This ., ~ . .
~ angle is directly related, in general, to the slope angle of . .
~; surface 104 relative to the vertical. This relationship can be seen in Figure 13j wherein the notch is illustrated in : ...
` phantom. In most instances, this angle "a" will be between about one and fifteen degrees, but this is not critical. In ...
. ~
die rule embodiments having a cylindrical inner bore, such as in Figures 7 and 8, angle "a" would appear to approach zero for strict geometrical reasons.
The notched configuration of the present invention also defines a pair of pyramidal notch surfaces 112 and 114 and an incidentally-occurring secondary cutting edge 116. The secondary cutting edge, of course, cuts only small portions of the stock material so that the cutting action is subs~antially unidirectionally along primary cutting edge 110 from one piercing point to the next. In some embodiments, edge 116 may even become purely vertical so that the entire cutting action is along a primary cutting edge 110. For definitional purposes, surfaces 110 and 11~ are considered to constitute a check-marked shaped edge interconnecting adjacent piercing points.
Pyramidal-shaped surface 112, the major pyramidal surface, is bounded on one side by primary cutting edge 110 and has a common side with secondary pyramidal surface 114. For definitional purposes, these surfaces are considered to define a generally boomerang-shaped notch configuration. However, it is not necessary that the notches be defined by these pyramidal surfaces. The important consideration would appear to be the ` combination of the piercing points, the major cutting edges establishing progressive angular cutting from one piercing point to the next, and the notches being formed on only one side of the chamfer.
Figure 12 also illustrates that the small angle "b"
defines a relatively shallow valley depth "d". This depth will, :, of course, be a direct result of the angle "h" and the distance between adjacent piercing points. For most applications of the present invention, this depth will not be more than about three ,' :' ~ - 12 "?
.-- . .
sixteenths (3/16) of an inch. In the more preferred embodiments, the depth of the valley will be no more than about 3/32, and may even be as shallow as 1/32 and 1/64 of an inch, depending upon the material to be cut. In the most preferred embodiment, the valley depth will result from angle "b" being from about 1 to 5. It will be recalled from the discussion relating to the embodiment of Figure 3 that this shallow valley depth has great significance when a resilient back up die pad supports the stock material. Specifically, for a notched die rule blade to com-pletely cut through stock material the cutting edge portion must project completely through the stock material and therefore into the resilient die pad material. This penetration depth is mini-mized in the present invention because of the shallow notch valley depth. Accordingly, the resilient die pad does not ex-perience the wear associated with prior art notched cutting edges.
The manner of using a cutting tool having the present cutting edge configuration is substantially identical to that of prior cutting tools. However, the cutting action created by :
the present invention is not the same as in the prior art.
Specifically, when the cutting tool is pressed into the stock material peaks 108 pierce the material to initiate the cutting . action. Continued movement of the cutting tool through the ` stock material results in a progressive cutting or slicing by the primary cutting edge substantially unidirectionally from one piercing point to the next. Further, the piercing points , . .~.
~ and primary cutting edges are formed by a notch which is only . . ..
- on one side of the cutting tool so that stock material exerts a resistive pressure substantially on only one side of the cutting , :,, tool which creates a unidirectional cutting pressure on the .
; - 13 -, ,;
, . ,~ .
., ,` ~ , .. . , , . . .,.- . -~06~;~9~
material being cut. These overall structural limitations and cutting method steps result in the reduced tonnage requirements previously explained.
It will be understood from the foregoing description that the rate of cutting action in the direction between the pierced points on the stock material will be dependent upon the angle of the cutting edges. Specifically, the cotangent for a one degree cutting edge is 57.29, the cotangent for a five degree cutting edge is 11.43 and the cotangent for a fifteen degree cutting edge is 3.73. Therefore, with a one degree cutting edge, the stock material will be cut at a rate of about 57.29 times the rate of relative movement between the cutting tool and stock material; with a five degree cutting edge, the stock material between the pierced positions will be cut at a rate of about 11.43 times the rate of relative movement between the cutting tool and stock material; and with a fifteen degree cutting edge, the stock material between the pierced positions will be cut by a rate in comparison with the rate of relative movement between the cutting tool and stock material of about 3.73:1.
It is to be understood that the description and explana-tion herein is merely exemplary of the overall invention and is not intended to be limiting in any respect. For example, the cutting edge configuration may be formed by other methods than grinding and may be used in all equivalent cutting tools.
- ~ , .
~' ... . . . . .. .
,, -
Claims (6)
1. An improved die rule having a plurality of generally equally spaced piercing points and primary cutting edges on a chamfered cutting portion, each of said cutting edges being substantially linear and extending from one piercing point substantially the entire distance to a next adjacent piercing point, each cutting edge and a line through the tips of the piercing points defining an acute angle between about one and five degrees, said piercing points and cutting edges being defined by notches formed in the die rule chamfer, said notches being defined by major and minor triangular-shaped notch faces between each piercing point, said major triangular face being bounded on one edge by a primary cutting edge, said notch faces having a common side, and the minor triangular face defining a secondary edge interconnecting the primary cutting edge with a next adjacent piercing point, said primary cutting edge and secondary edge defining a generally check-marked shaped edge configuration between each pair of adjacent piercing points.
2. In a method of cutting blanks from stock material, the steps of positioning the stock material in alignment with a die rule, relatively moving the die rule and stock material toward one another, initially contacting the stock material by a plurality of generally equally spaced peaks on a cutting por-tion of the die rule, thereby piercing the stock material at a plurality of generally equally spaced positions, continuing to relatively move the material and the die rule and cutting the stock material between the plurality of pierced positions with a plurality of primary cutting edges, each of said primary cutting edges (a) extending from one piercing peak substantially the entire distance to the next piercing peak and (b) extending away from the stock material by an angle of from about one to fifteen degrees with a line connecting the piercing peaks, said cutting edges thereby progressively cutting the stock material substantially unidirectionally from one pierced position pro-gressively toward a next adjacent pierce position.
3. A method as claimed in claim 2, wherein the pro-gressive cutting of the stock material by the cutting edges is effected by an amount, in comparison with the extent of the relative movement between the cutting tool and the stock material, within the ratios of between about 57.29:1 and 3.73:1.
4. In a method of cutting stock material, the steps of: positioning the stock material on a resilient die pad in alignment with a cutting die rule, said die rule having a cham-fered portion defined by two converging surfaces which inter-sect to form a cutting portion, said cutting portion having formed thereon a plurality of notches which define a plurality of generally equally spaced piercing points and a plurality of sub-stantially linear primary cutting edges extending from each pierc-ing point substantially the entire distance to an adjacent piercing point, said primary cutting edges extending away from said piercing points by an angle of no more than fifteen degrees, thereby forming a valley on the cutting portion between each piercing point, said valley having a depth of no more than three sixteenths of an inch; relatively moving the stock material and the die rule toward one another, and in a substantially simul-taneous, sequential operation (a) initially penetrating the stock material at a plurality of positions with the die rule piercing points, (b) cutting the stock material with the primary cutting edges in a direction away from each initially penetrated position toward a next adjacent penetrated position, whereby the stock material between each penetrated position is cut substantially the entire distance therebetween in a progressive cutting action in substantially only one direction, and (c) pressing the piercing points through the stock material and into the resilient die pad by a distance of not more than about three sixteenths of an inch due to the shallow valley depth on the cutting portion, at which depth the stock material will be cut through its entire depth by the cutting edges; and retracting the stock material from the die rule and die pad.
5. In a method of cutting blanks from stock material, the steps of: positioning the stock material in alignment with a cutting tool having a pair of converging side faces; relatively moving the cutting tool and stock material toward one another (a) to initially pierce the stock material at a plurality of generally equally spaced positions by a plurality of generally equally spaced peaks on a cutting portion of the cutting tool, and thereafter (b) to progressively cut the stock material substan-tially unidirectionally from each of the pierced positions toward a next adjacent pierced position with a plurality of primary cutting edges formed on the cutting tool, each of said primary cutting edges extending from one piercing peak substantially the entire distance to the next piercing peak and extending away from the stock material by an angle of from about 1° to 5° with a line connecting the piercing peaks.
6. A method as claimed in claim 5, wherein the primary cutting edges are formed by a plurality of equally spaced notches on only one of said side faces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA298,780A CA1064390A (en) | 1975-06-11 | 1978-03-13 | Compound angle cutting edge and method of using same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/585,802 US3961858A (en) | 1975-06-11 | 1975-06-11 | Compound angle cutting edge |
| CA244,432A CA1069428A (en) | 1975-06-11 | 1976-01-28 | Compound angle cutting edge and method of using same |
| CA298,780A CA1064390A (en) | 1975-06-11 | 1978-03-13 | Compound angle cutting edge and method of using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1064390A true CA1064390A (en) | 1979-10-16 |
Family
ID=27164302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA298,780A Expired CA1064390A (en) | 1975-06-11 | 1978-03-13 | Compound angle cutting edge and method of using same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1064390A (en) |
-
1978
- 1978-03-13 CA CA298,780A patent/CA1064390A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4002092A (en) | Compound angle cutting edge and method of using same | |
| US5555759A (en) | Workpiece-deforming tool and die for use in a punch press | |
| US3961858A (en) | Compound angle cutting edge | |
| WO1987000116A1 (en) | Method and tool for punching plaster plates | |
| US3277764A (en) | Apparatus for working corrugated board or the like | |
| US5093999A (en) | Vegetation cutting tool and method of manufacture | |
| US2423601A (en) | Shear for frangible materials | |
| CA1064390A (en) | Compound angle cutting edge and method of using same | |
| CA2275013A1 (en) | Method and apparatus for scarfing a plate-like material | |
| CN211991198U (en) | Plate shearing machine for machining | |
| CA1062604A (en) | Compound angle cutting edge and method of using same | |
| US2590024A (en) | Method of making pinking scissors | |
| CA1061706A (en) | Compound angle cutting edge and method of using same | |
| US3354768A (en) | Rotary cutters for sheet material | |
| CN212169206U (en) | High-efficient high-yield special cutting blade | |
| CN217434385U (en) | Rotary shaver blade, cutter head and cutter foot | |
| CN213259840U (en) | Cloth perforating machine | |
| JPH07275964A (en) | Passing cut die for punch press and passing cut method | |
| CN218453092U (en) | Ceramic tile cutting device | |
| CN210650942U (en) | Frock is cuted to automotive decoration spare material handle | |
| CN219633996U (en) | Punching tool | |
| CN210280860U (en) | Square tube cutting machine | |
| CN213002170U (en) | Cutting and stamping device for die machining | |
| CN218549339U (en) | Simple wire stripper | |
| CN215848537U (en) | Continuous machining mechanism of punch press for cutting protective equipment |