Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
  • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
  • B26D7/26—Means for mounting or adjusting the cutting member; Means for adjusting the stroke of the cutting member
  • B26D7/2614—Means for mounting the cutting member
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/38—Cutting-out; Stamping-out
  • B26F1/44—Cutters therefor; Dies therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
  • B26D7/00—Details of apparatus for cutting, cutting-out, stamping-out, punching, perforating, or severing by means other than cutting
  • B26D7/26—Means for mounting or adjusting the cutting member; Means for adjusting the stroke of the cutting member
  • B26D2007/2607—Means for mounting or adjusting the cutting member; Means for adjusting the stroke of the cutting member for mounting die cutters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/38—Cutting-out; Stamping-out
  • B26F1/384—Cutting-out; Stamping-out using rotating drums
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/38—Cutting-out; Stamping-out
  • B26F1/44—Cutters therefor; Dies therefor
  • B26F2001/4472—Cutting edge section features
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/38—Cutting-out; Stamping-out
  • B26F1/44—Cutters therefor; Dies therefor
  • B26F2001/4481—Cutters therefor; Dies therefor having special lateral or edge outlines or special surface shapes, e.g. apertures

Definitions

• This invention relates to a die cutting insert for a rotary die cutter and the die itself. More specifically, this invention relates to a replaceable and/or interchangeable die cutting insert for a rotary die which can be used to cut absorbent articles from a web of material.
• a rotary die cutter includes a rotatable anvil roll which cooperates with a rotatable knife shaft assembly.
• the knife shaft assembly has an outer circumference with at least one die cutter associated therewith.
• the knife shaft assembly cooperates with the anvil roll to form a nip through which a web of material can pass. As a web of material passes between the nip, the die cutter will cut the material into a predetermined shape. Since the nip between the anvil roll and the knife shaft assembly is very small, it is necessary that the anvil roll and the knife shaft assembly be manufactured to very close tolerances. Because of the close tolerances, most rotary die cutters utilize a solid die shaft having the die cutters integrally formed thereon.
• Rotary die cutters are used in many different industries to cut many different types of material.
• rotary die cutters can be employed to cut paper, cardboard, plastic, laminates formed of two or more layers, absorbent materials such as wood pulp fluff, webs formed from natural or synthetic fibers, cellulose fluff, tissue, cotton, rayon and various other types of woven and nonwoven materials.
• Rotary die cutters are particularly useful in cutting a plurality of layers of different material which have been assembled to form an absorbent article such as a sanitary napkin or a pantiliner.
• Such products are normally constructed, from top to bottom, of a liquid-permeable cover sheet, one or more absorbent layers, a liquid-impermeable baffle, a layer of garment attachment adhesive and a removable peel strip.
• the various layers are normally bonded together by a construction adhesive and the article usually has a total thickness of between about 0.1 inches to about 1.0 inch.
• Each replaceable and/or interchangeable die cutting insert has a unique configuration and includes mounting means for properly securing it to the outer circumference of a knife shaft assembly.
• this invention relates to a replaceable and/or interchangeable die cutting insert for a rotary die cutter and the die itself.
• the insert includes an arcuately-shaped base formed on a pre-determined radius.
• the base has first and second spaced apart ends and first and second oppositely aligned surfaces.
• a continuous knife is integrally formed about the outer periphery of the first surface.
• the knife has a cutting edge and first and second side walls.
• the knife edge has a thickness of less than about .005 inches and the first side wall is aligned approximately pe ⁇ endicular to the cutting edge.
• the second side wall is aligned at an angle of at least about 15° relative to the cutting edge.
• the die cutting insert also includes a mechanism for removably attaching it to a die cutting shaft.
• the mechanism can include at least one aperture formed adjacent to each end of the base. The apertures extend completely through the base and are designed to receive threaded bolts. The bolts are selected and sized to mate with the apertures and secure the base to the die cutting shaft.
• the general object of this invention is to provide a replaceable and/or interchangeable die cutting insert for a knife shaft assembly.
• a more specific object of this invention is to provide a rotary die cutter having a rotatable anvil and a rotatable knife shaft assembly with one or more replaceable die cutting inserts mounted to the outer circumference of a die shaft.
• Another object of this invention is to provide a knife shaft assembly having replaceable and/or interchangeable die cutting insert attached thereto which can be removed without requiring the inserts to be reground in order to obtain the right clearance nip between the anvil roll and the knife shaft assembly.
• a further object of this invention is to provide a replaceable and/or interchangeable die cutting insert which can quickly and easily be removed and/or attached to a die shaft.
• Still another object of this invention is to provide a replaceable and/or interchangeable die cutting insert which can easily be properly secured to a die shaft at a predetermined torque value.
• an object of this invention is to provide a rotary die cutter having a rotatable anvil roll mating with a rotatable knife shaft assembly to form a nip therebetween and having one or more replaceable and/or interchangeable die cutting inserts mounted about its outer circumference of the knife shaft.
• Fig. 1 is a schematic of a rotary die cutter showing a rotatable anvil roll cooperating with a rotatable knife shaft assembly to form a nip therebetween and having a web of material passing through the nip.
• Fig. 2 is a perspective view of a replaceable and/or interchangeable die cutting insert.
• Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. 2 showing the cutting edges and the mounting holes for attaching the insert to a die shaft.
• Fig. 4 is an exploded, cross-sectional view of a portion of the replaceable and/or interchangeable die cutting insert mounted to a portion of the outer circumference of the die shaft.
• a rotary die cutter 10 which includes a rotatable anvil roll 12 cooperating with a rotatable knife shaft assembly 13.
• the anvil roll 12 can be constructed of a ferrous or non-ferrous metal and should have a smooth surface.
• the anvil roll 12 can be formed from a material which is compressible, such as neoprene rubber or from a non-compressible material, such as steel. For most applications, it is preferred that the anvil roll 12 be a metal roll.
• the knife shaft assembly 13 includes a die shaft 14 with an outer circumference 16 and at least one replaceable and/or interchangeable die cutting insert 18 mounted onto the die shaft 14.
• replaceable it is meant that the insert 18 can be unbolted and removed from the die shaft 14, cleaned, reground or machined in some fashion and then secured back onto the die shaft 14 in its original position.
• interchangeable it is meant that each of the die inserts 18 is capable of being mutually interchanged with any other insert 18. This interchangeability feature is very important because, up until now, it has been virtually impossible to produce replaceable and interchangeable inserts 18 for a rotary die cutter 10 while still maintaining the nip dimension between the anvil roll 12 and the knife shaft assembly 13.
• the knife shaft assembly 13 can be constructed of a metal, for example steel, and should have an outer circumference machined to a very close tolerance.
• the die shaft 14 can have one or more, preferably several die cutting inserts 18 mounted to its outer circumference 16. As depicted in Fig. 1, there are four die cutting inserts 18 equally spaced about the outer circumference 16 of the die shaft 14.
• the anvil roll 12 and the knife shaft assembly 13 cooperate to form a nip 20 therebetween through which a web of material 22 can pass. As the anvil roll 12 and the knife shaft assembly 13 are rotated in opposite directions, the web of material 22 can pass through the nip 20 and be cut by the die cutting inserts 18 into individual articles 24.
• the articles 24 can be transported by conventional means, such as a conveyor 26, to a location where they can be stacked, packaged and later shipped.
• Any waste trim 30 from the rotary die cutter 10 can be directed away from the nip 20 by a conduit 28 using vacuum, air pressure, gravity or mechanical means.
• the waste trim 30 can then be collected in a hopper 32 for possible recycling or some other means of disposal.
• a replaceable and/or interchangeable die cutting insert 18 is shown before it is secured to the die shaft 14.
• the replaceable and/or interchangeable die cutting insert 18 has an arcuately-shaped base 34 formed on a predetermined radius.
• the base 34 has first and second spaced apart ends, 36 and 38 respectively, and first and second oppositely aligned surfaces, 40 and 42 respectively.
• the first surface 40 will face the anvil roll 12 when the inserts 18 are assembled onto the knife shaft assembly
• the second surface 42 will be concave so as to match the outer circumference 16 of the die shaft 14 onto which the insert 18 is to be secured. It is common to machine the second surface 42 to have a tolerance of plus or minus .0001 inches so as to facilitate a proper attachment between the die cutting insert 18 and the die shaft 14. If the second surface 42 is not machined to closely match the outer circumference 16 of the die shaft
• the die cutting insert 18 is shown having a knife 44 which is integrally formed about the periphery of the first surface 40.
• the knife 44 is a continuous element but could be serrated if desired.
• the knife 44 has a cutting edge 46 and first and second side walls, 48 and 50 respectively.
• the cutting edge 46 has a width of less than about .005 inches.
• the width of the cutting edge 46 is between about .0005 to about .004 inches, and most preferably, the width is between about .001 to about .002 inches.
• the width of the cutting edge 46 is very important because if the thickness becomes too great, it will be more difficult to cleanly cut the material 22 passing through the nip 20. For example, instead of making a clean cut, the cutting edge 46 could compressed the material 22 and allow the material 22 to be torn or broken and thereby produce a ragged cut.
• the first side wall 48 is aligned approximately pe ⁇ endicular to the cutting edge 46.
• the first side wall 48 is coextensively aligned with the outside periphery 52 of the base 34.
• the first side wall 48 will be aligned pe ⁇ endicular, that is at 90 degrees, to the cutting edge 46.
• the second side wall 50 is aligned in an angle of at least about 15° relative to the cutting edge 46.
• the second side wall 50 is located inward of the first side wall 48 and terminates at a third surface 54.
• the third surface 54 is located intermediate the first surface 40 and the second surface 42.
• the third surface 54 is spaced below the first surface 40 by a distance "d".
• the actual distance between the first surface 40 and the third surface 54 can vary but normally will be about equal to the thickness of the article 24 which is to be cut.
• the distance of the third surface 54 below the first surface 40 can be between about 0.1 inches to about .125 inches.
• the distance “d” also represents the height of the knife 44.
• the distance "d” can be affected by the type of material 22 which is being cut, the thickness of the material, whether the material is compressible, whether the material is formed from a single layer or from a plurality of layers, whether the layers are bonded together by an adhesive, as well as the particular characteristics of the material itself.
• a thermoplastic film may react differently to be cut than a fibrous nonwoven web.
• the second side wall 50 is aligned at an angle ⁇ of at least about 15° relative to the cutting edge 46.
• the angle ⁇ is between about 15° to about 50° relative to the cutting edge 46, and more preferably, the angle ⁇ is between about 15° to about 40° relative to the cutting edge 46.
• the second side wall 50 be angled relative to the cutting edge 46 at an angle ⁇ of at least about 15° because the design of the insert 18 leaves very little support for the knife 44. Since the first side wall 48 is approximately pe ⁇ endicularly aligned to the cutting edge 46, all support provided to the knife 44 will have to come from the material present between the first side wall 48 and the second side wall 50. If the angle ⁇ is less than about 15°, there is a high probability that the cutting edge 46 will crack or chip as the material 22 is being cut because the forces acting on the cutting edge 46 can become very high.
• the replaceable and/or interchangeable die cutting insert 18 further includes means for removably attaching the base 34 to at least a portion of the outer circumference 16 of the die shaft 14.
• the die shaft 14 can have one or more, and preferably a plurality of replaceable and/or interchangeable die cutting inserts 18 mounted about its outer circumference 16.
• the inserts 18 can be arranged so that they are equally spaced apart from one another or they can be arranged such that the outer periphery of one will contact the outer periphery of an adjacent insert 18.
• One means for removably attaching the die cutting inserts 18 to the die shaft 14 includes forming at least one aperture 56 adjacent to each of the first and second ends, 36 and 38 respectively.
• a pair of apertures 56 are formed adjacent to each of the ends, 36 and 38 respectively, so as to permit each insert 18 to be correctly secured to the die shaft 14 without introducing unwanted forces into each insert 18.
• Each of the apertures 56 extends completely through the base 34 from the third surface 54 to the second surface 42.
• the apertures 56 are not threaded but do contain a counterbore 58 located adjacent to the third surface 54.
• Each counterbore 58 is sized and configured to receive the head of a machine bolt 60, see Fig. 4, which will attach the insert 18 to the die shaft 14.
• a threaded machine bolt 60 is shown positioned in one of the apertures 56.
• the bolt 60 is aligned with and threaded into a threaded bore or aperture 62 formed in the die shaft 14.
• the bolt 60 contains a head 64 and a threaded shank 65.
• the head 64 is larger than the threaded shank 65 and is designed to seat in the counterbore 58 when the insert 18 is mounted onto the die shaft 14. When assembled, the head 64 will be flush with the third surface 54.
• Each of the machine bolts 60 can have a predetermined thread pitch. In addition, the length of the threads and the number of threads per inch can vary depending upon one's application. The size and style of the bolts 60 can be selected depending upon the size and configuration of the replaceable and/or interchangeable die cutting insert 18. It should be noted that it is desirable to tighten the bolts 60 to a relatively high torque setting, for example between about 100 pounds per square inch (psi) to about 1000 psi.
• each bolt 60 is tightened to a torque setting of between about 200 psi to about 500 psi, and more preferably, between about 400 psi to about 500 psi.
• a fine thread be used instead of a course thread.
• One bolt size which works well in mounting an insert measuring about six inches in length, about two inches in width and about .75 inches in depth to a die shaft 14 is a bolt 60 having the following diameter (inches) and thread .3125-24 UAF.
• the bolts 60 should be sized and configured to mate with each pair of the coaxially aligned apertures 56 and 62. It should be noted that when each of the die cutting inserts 18 contains a single aperture 56 formed adjacent to each end, 36 and 38 respectively, that only two threaded bolts 60 will be required to secure each insert 18 to the die shaft 14. However, when each of the die cutting inserts 18 contains two apertures 56 formed adjacent to each end, 36 and 38 respectively, four threaded bolts 60 will be required to secure each insert 18 to the die shaft 14.
• one of the threaded bores 62 is shown. It should be realized that there will be a plurality of threaded bores 62, one for each of the corresponding apertures 56 formed in each of the inserts 18. It is possible to arrange the threaded bores 62 in the die shaft 14 such that various sizes of inserts 18 can be assembled onto the die shaft 14 at a later time. By forming more threaded bores 16 than needed and arranging them at different locations about the outer circumference 16 of the die shaft 14, one can use a single die shaft 14 to accommodate two or more different style of die cutting inserts 18. It has also been found to be extremely advantageous to form a counterbore 66 at the open end of each of the threaded bores 62.
• Each counterbore 66 begins at the outer circumference 16 of the die shaft 14 and has a depth of at least about .05 inches. Preferably, the depth will range from about .1 inches to about .2 inches, and more preferably, the depth will range between about .1 inches and about .15 inches. A depth of about .125 inches works well when the threaded bores 62 have a diameter of about .3125 inches or greater.
• the presence of the counterbores 66 are important for they functions to relieve compressive stresses in the metal from which the die shaft 14 is constructed. Such force can occur as the replaceable and/or interchangeable die cutting inserts 18 are secured to the die shaft 14.
• the insert 18 can also contains a pin hole 68 formed at the intersection of the central longitudinal axis X— X and the central transverse axis Y-Y.
• the pin hole 68 is designed to be coaxially aligned with a hole or bore formed in the die shaft 14 such that a pin can be inserted through the pin hole 68 and serve to physically align the insert 18 onto the die shaft 14.
• the bolts 60 can be threaded into the threaded bores 62.
• the pin hole 68 is an optional feature and is present only for convenience in mounting the insert 18 onto the die shaft 14.

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• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)

Applications Claiming Priority (5)

Publications (2)

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ID=26681410

Family Applications (1)

Country Status (6)

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• 1996
  • 1996-12-19 JP JP09526335A patent/JP2000503262A/ja not_active Abandoned
  • 1996-12-19 KR KR10-1998-0705750A patent/KR100441574B1/ko not_active Expired - Fee Related
  • 1996-12-19 EP EP96945072A patent/EP0876246B1/de not_active Expired - Lifetime
  • 1996-12-19 DE DE69628668T patent/DE69628668T8/de not_active Expired - Fee Related
  • 1996-12-19 AU AU13528/97A patent/AU1352897A/en not_active Abandoned
  • 1996-12-19 WO PCT/US1996/020711 patent/WO1997027033A1/en not_active Ceased

Non-Patent Citations (1)

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