METHOD FOR FORMING DIES

• US 3,661,577 A
• Filed: 03/12/1968
• Issued: 05/09/1972
• Est. Priority Date: 03/12/1968
• Status: Expired due to Term

• Current Assignee: Atlas Steel Rule Die Incorporated
• Original Assignee: Carl John Klemm, Richard August Tietz, Terrell Ray Street, Trevor Blake
• Inventors: Klemm, Carl John, Tietz, Richard August, Street, Terrell Ray, Blake, Trevor
• Primary Examiner(s): Torchin, Norman G.
• Assistant Examiner(s): Kimlin, Edward C.
• Application Number:
  US04/712,526
• Time in Patent Office: 1,519 Days
• Field of Search: 96/38.2,41,36,27
• US Class Current: 430/22
• CPC Class Codes: B23P 15/406 rotary or plane die cutters

Abstract

A die for cutting paperboard material or the like comprises a pair of die plates having coacting cutting elements which partially overlap in the plane of the material to be cut. In making the die plates, a first image representing the critical overlap portion of the cutting elements is utilized to obtain a second and third image each representing a complete cutting element. The second and third image each includes an overlap portion derived from a common image source thereby to facilitate accuracy of registry of two matching die plates ultimately derived from said second and third images.

Claims

2. In a method of producing die members according to claim 1;

comprising exposing a sheet of film through the base thereof and through a spacer onto separate sheets of raw film to obtain orientation reversal of said first and second images leading toward production of a pair of matched, coacting, die plates.

3. In a method of producing die members according to claim 2 wherein the thickness of said spacer and the thickness of the backing on said sheet of film are substantially equal.

4. In a method of producing die members according to claim 1 wherein images representing portions of the cutting elements adjacent the overlapping section are borne on sheets of film;

exposing one of said sheets of film through the base thereof and another of said sheets of film through a spacer onto separate sheets of raw film to obtain relative orientation reversal of said images leading toward production of a pair of matched, coacting, die plates.

5. In a method of producing coacting die plates each having one of a coacting pair of cutting elements and one of a coacting pair of scoring elements, comprising:

forming a first and second image each having portions of its respective outline in related correspondence with and other portions thereof displaced from related correspondence with the outline of the respective cutting elements of said die plates;

one of said images having sections in related correspondence with one of said scoring elements;

forming a third image in related correspondence with predetermined common parts of the cutting elements;

said third image having sections in related correspondence with another of said scoring elements;

optically transferring said first and second images onto separate photosensitive surfaces;

optically transferring the images of said predetermined common parts onto said photosensitive surfaces in register with its other transferred image, whereby the images of said predetermined common parts predominate over said first and second images as to the portions of outline of the latter images which are displaced from related correspondence with the outline of the respective cutting elements, so that each image imposed on each photosensitive surface is a composite of the two images from which it is derived.

6. The method according to claim 5 wherein one of said coacting pair of scoring elements includes a male scoring element, the longitudinal axis of which is centered on a desired score line to be formed in said sheet material and the other of said coacting pair of scoring elements includes a female scoring element having two raised areas generally parallel to and having their longitudinal axes slightly and equally spaced on opposite sides of said score line;

said third image also having a section representing said male scoring element whereby the relative location, on one photosensitive surface, of the image representing the male scoring element and the image in related correspondence with predetermined common parts of the cutting elements is independent of the registry of said sequential optical transference of images onto said one photosensitive surface.

7. In a method as set forth in claim 5, wherein said photosensitive surfaces comprise photosensitive plates;

removing by chemical means material from said plates except in regions bearing said imposed images to produce a pair of matched, coacting die plates having the working surfaces as integral parts thereof in the form of raised lands above the background areas of said plates.

8. In a method of producing a die comprising a pair of opposed coacting die members each having one of a coacting pair of cutting elements, said cutting elements having sections overlapping one another in the general plane of the material being cut thereby, which method comprises the steps of;

forming a first image representing the overlapping sections of said cutting elements;

forming a second image representing a section of a cutting element of one die member;

forming a third image representing a section of the cutting element of the other die member;

optically combining said first image and said second image to produce a first composite image representing one cutting element;

optically combining said first image and said third image to produce a second composite image representing the other cutting element;

whereby each composite image representing said pair of cutting elements has a section derived from a common image source representing the overlapping section of said cutting elements.

9. In a method for producing a die for forming a line of severence in a sheet material, said die comprising a pair of opposed, coacting die members, each die member having one of a coacting pair of cutting elements, each of said coacting pair of cutting elements having an overlap portion and a backup portion, said overlap portions overlapping one another in the general plane of the sheet material being cut, the method comprising the steps of:

forming an image representing the overlap portion of the cutting elements, forming two images, each representing one of the cutting elements, combining said images to obtain two composite images, each exceeding the width of the backup of one of the cutting elements;

optically combining each of said composite images with said image representing the overlap in a manner to produce resulting images representing the backup plus overlap of the cutting elements.

10. In a method as set forth in claim 9 further comprising:

stepping and repeating each of said composite images onto separate sheets of film so that each of the latter bears multiple like images thereon;

stepping and repeating said image representing the overlap onto a sheet of film so that the latter bears multiple, like images;

said sheets of film being optically combined as aforesaid to produce a plurality of like images each representing the backup plus overlap of the cutting elements.

11. In a method as set forth in claim 10 wherein said stepping and repeating steps are effected in the same sequen-tial order.

12. In a method as set forth in claim 9 wherein said images representing each cutting element are born on sheets of film;

exposing one film sheet associated with one of the cutting elements through the base thereof to impose its images onto raw film with the same orientation;

exposing another sheet of film associated with the other cutting element through a spacer onto raw film to obtain lateral reversal of the image;

wherein the images representing the cutting elements imposed on said sheets of raw film are reversed relative to one another leading toward production of a pair of matched coacting die plates.

13. In a method as set forth in claim 9 wherein said image representing the overlap is initially born on one sheet of film;

exposing said latter film sheet through the base thereof to impose the overlap image onto raw film with the same orientation;

exposing said one sheet of film representing the overlap through a spacer onto raw film to obtain lateral reversal of the overlap image;

wherein the imageS representing the overlap imposed on said sheets of raw film are reversed relative to one another leading toward production of a pair of matched coacting die plates.

14. In a method of producing a die for forming a line of severance in a sheet of material, said die comprising a pair of opposed, coacting die members each having one of a coacting pair of cutting elements, each of said cutting elements having an overlap portion and a backup portion, said overlap portions overlapping one another in the general plane of the sheet material being cut, the method comprises the steps of:

forming a first image representing the overlapping portions of said cutting elements;

forming a second image representing one of the cutting elements;

forming a third image representing the other of the cutting elements;

optically combining said first, second and third images in two separate steps to produce two separate composite images each exceeding the width of the backup of one of the cutting elements by light lock;

optically combining each of said composite images with said image representing the overlap in a manner to cancel out the light lock so that the resulting images represent the backup plus overlap of the cutting elements.

15. In a method as set forth in claim 14 wherein one of said two separate steps of combining said first, second, and third images to produce a composite image comprises, utilizing the first and second image to block light from predetermined sections of the third image to produce the aforesaid light lock on one of said combined images.

16. In a method for producing a die for working a sheet up of material along a pre-selected pattern of cut lines, said die comprising a pair of opposed coacting die members, each die member having one of a coacting pair of cutting elements, each of said cutting elements having an overlap portion and a backup portion, said overlap portions overlapping each other in the general plane of the sheet material being cut, comprising the steps of:

forming a first drawing having a plan image of the area common to both cutting elements representing said overlapping portions of said cutting elements, said common area being centered on and substantially coincident in length to the desired line of severance to be formed in said sheet material;

completing said drawing to include the plan images of both cutting elements, said drawing being related to the degree of undercutting resulting from chemical removal of material in forming said die;

optically transferring the plan image representing the overlapping portions on the first drawing onto a first sheet of film;

optically transferring the plan image of the first of said cutting elements onto a second sheet of film and the plan image of the second of said cutting elements onto a third sheet of film;

said plan image of the first cutting element being marked on said completed drawing in the combination of a first indicating medium and a second indicating medium, said plan image of said second cutting element being marked on said completed drawing in the combination of a second indicating medium and a third indicating medium;

the second indicating medium indicating said common area on said first and said completed drawing;

said first and third indicating media being optically separable from each other and said second indicating medium being optically combinable with either of said first and third indicating media under conditions which exclude the other of said first and third media;

optically transferring the images on the first and second, and the first and third sheets of film, each pair in register with one another, onto separate photosensitive surfaces whereby the images imposed on one photosensitive surface is a composite of the images born on the first and second sheets of film and the images imposed on the other photosensitive surface is a composite of the images born on the first and third sheets of film.

17. THe method according to claim 16 wherein one die member has a coacting set of scoring elements including a male scoring element, the longitudinal axis of which is centered on a desired score line to be formed in said sheet material and the other die member has a female scoring element comprising two raised areas generally parallel to and having their longitudinal axes slightly and equally spaced on opposite sides of said score line;

said first drawing including the plan image of said male scoring element;

said plan image of the male scoring element being marked on said first drawing with said first indicating medium;

optically transferring the plan image representing the male score element and the plan image representing the overlapping portions onto said first sheet of film.

18. The method according to claim 16 wherein said first and third indicating media are complementary colors and said exclusion is effected by passing said optical transmission through color filters.

19. The method according to claim 17 wherein said female scoring element is marked on said completed drawing with said third indicating medium;

optically transferring the plan image representing the female score element and the plan image representing one of said cutting elements onto said second sheet of film.

20. The method according to claim 17 wherein one die member has a male scoring element, the longitudinal axis of which is centered on a desired score line to be formed in said sheet material and the other die member has a female scoring element comprising two raised areas generally parallel to and having their longitudinal axes slightly and equally spaced on opposite sides of said score line;

said completed drawing including the plan images of said scoring elements;

said plan image of the male scoring element being marked on said completed drawing in the combination of said second indicating medium and said third indicating medium.

21. In a method of producing die plates, having coacting cutting elements, comprising:

forming a first and second image each having portions of its respective outline in related correspondence with the outline of respective cutting elements of said die plates;

forming a third image in related correspondence with common overlapping sections of said cutting elements;

optically transferring said first and third, and said second and third images, onto separate photosensitive surfaces whereby the images imposed on one surface is a composite of the first and third images and the image imposed on the other surface is a composite of the second and third images.