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US 4,226,143 AGranted
Method of making steel rule type piercing and blanking dies
OwnerGraydon D. Whitecotton, Walley E. Whitecottoninventors
Life of this patent
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OwnerGraydon D. Whitecotton, Walley E. Whitecottoninventors
Estimating the term…
A steel rule first die is made by mounting steel rule elements, and other shearing elements if desired, in a die block in known manner. A punch die blank is mounted on a support having means for aligning the blank with such shearing elements. One or more layers of adhesive tape of predetermined thickness are applied to the shearing side face of the shearing elements to define a clearance-producing layer thereon. Foamed plastic blocks are adhered to the punch blank so as to form defined areas on its face opposite the shearing elements of the first die, and an adherent impressionable soft layer of hardenable resin is applied to such defined areas. The first die is then assembled in aligned relation with the punch die blank, with its shearing elements impressed deeply in the soft resin layer so as to form wide edge faces in such layer against the clearance-producing layer of tape on the shearing side faces of the shearing elements. The resin layer is hardened and the punch blank is then removed from the assembly with the die element impression fixed thereon. The edge faces are desirably coated with a contrasting color which may penetrate the hardened resin. The punch blank is then machined to the hardened impression, and the machining step is controlled in accordance with removal of color from the edge faces which define the die element impression. This forms a punch which accurately matches the shearing elements of the first die, with clearance therefrom corresponding to the thickness of the tape. The tape and resin are removed, and the steel rule die and the punch are mounted in a die set for use.
The method of making steel rule dies, comprising
The method of making steel rule dies, comprising
The method of making a punch die to match a first die having shearing elements with shearing side faces thereon, in which a punch blank is coated with a soft impressionable thick layer of hardenable resin over areas thereof opposite the shearing elements of the first die and such shearing elements are impressed in the resin layer and the layer then hardened to produce a fixed impression of the shearing elements defined by wide edge faces of the hardened resin, and the punch blank is machined to such edge faces to produce a punch matching the shearing elements of the first die, which includes the improvement comprising the step of applying to the shearing side faces of said shearing elements a clearance-producing layer of tape or the like, before impressing said shearing elements in the resin layer, so that the edge faces of the impression will provide for clearance between the first die and the punch produced by machining the punch blank to such edge faces.
The method of making a punch die to match a first die having shearing elements with shearing side faces thereon, in which a punch blank is coated with a soft impressionable thick layer of hardenable resin over areas thereof opposite the shearing elements of the first die and such shearing elements are impressed in the resin layer and the layer then hardened to produce a fixed impression of the shearing elements defined by wide edge faces of the hardened resin, and the punch blank is machined to such edge faces to produce a punch matching the shearing elements of the first die, which includes the improvement comprising the step of applying contrasting coloring material to the wide edge faces of the hardened resin before machining the punch blank to such edges, and controlling the machining in accordance with removal of contrasting color from such edges by the machining.
The method of making a punch die to match a first die having shearing elements with shearing side faces thereon, in which a punch blank is coated with a soft impressionable thick layer of hardenable resin over areas thereof opposite the shearing elements of the first die and such shearing elements are impressed in the resin layer and the layer then hardened to produce a fixed impression of the shearing elements defined by wide edge faces of the hardened resin, and the punch blank is machined to such edge faces to produce a punch matching the shearing elements of the first die, which includes the improvement comprising the step of affixing barrier elements to the punch blank to form defined areas thereon at and adjacent the positions of shearing elements on the first die, and applying the resin layer to such defined areas, the barrier elements serving to confine the resin into close conformity with the shearing faces of the shearing elements impressed therein.
Dependencies are inferred from the claim text.