Lightweight dimensionally stable steel rule die
OwnerRussell Brayton, Michael Kush +1inventors
InventorsRussell Brayton, Michael Kush, Robert McArtan
Life of this patent
Estimating the term…
Abstract
A lightweight, dimensionally stable steel rule die for cutting and scoring carton blanks having a die board containing the cutting and scoring rules which is formed of a laminated plastic construction adapted to register and coact with a steel counterplate over prolonged production runs and maintain registration within a tolerance range of about ±0.002 inches.
Claims20
A flat board die assembly for cutting and scoring carton blanks formed of paperboard and the like, comprising:
- a die board having opposed major surfaces and a plurality of marginal side surfaces, said die board having a plurality of slots receiving rules therein, said slots and said rules having thicknesses sized to permit a friction fit of said rules inside said slots, said die board having a lightweight construction no greater than about three pounds per square foot;
- and
- a die chase surrounding the marginal edges of said die board;
- and
- means operatively connected to said die board and said die chase for maintaining positional relation between said rules within a range of about ±0.002 inches.
A flat board die assembly for cutting and scoring carton blanks formed of paperboard and the like, comprising:
- a die board having opposed major surfaces and a plurality of marginal side surfaces, said die board having a plurality of slots receiving rules therein, said slots and said rules having thicknesses sized to permit a friction fit of said rules inside said slots, said die board having a lightweight construction no greater than about three pounds per square foot, said die board further having a laminated structure including an inner core which is of a rigid polyurethane material, said inner core having opposed major surfaces, said die board further having a cover sheet secured to one of said opposed major surfaces, said cover sheet formed of a different material than said inner core;
- a steel counterplate coacting with said rules in said die board to produce cutting and scoring impressions in the carton blanks;
- and
- a die chase surrounding the marginal edges of said die board.
A method for producing a lightweigt, dimensionally stable rule die for cutting and scoring carton blanks formed of paperboard and the like, comprising the acts of:
- providing a die board inner core composed of a polyurethane material and a first die board cover sheet composed of a more rigid material;
- forming a plurality of slots in said inner core for receiving a corresponding plurality of cutting and creasing rules, said slots being sized smaller than said rules so as to provide a friction fit therewith, said inner core slots formed in a pattern for registration with said cover sheet slots but spaced a lesser distance apart based upon a compensation factor X determined according to the following formula:
- X=1−N(Ke)/L
- wherein N equals the number of rules in a selected axial direction, Ke equals the amount of expansion per slot which occurs when the rules are inserted in the inner core slots, and L equals the total length of the inner core along the selected axial direction;
- adhesively bonding said first cover sheet to said inner core;
- and
- inserting said rules through said cover sheet slots and into said inner-core slots.
Dependencies are inferred from the claim text.