Urethane dies
AssigneeChrysler Corporation
InventorWilliam G. Krowl
Life of this patent
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Abstract
A forming tool made from resins and fillers for the cold forming of sheet metal and especially suitable for forming short runs of sheet metal parts with drop hammers, hydraulic presses or mechanical crank presses, the filler being a mixture of iron filled resin and an aggregate; the aggregate being a lightweight by-product of the steel making process.
Claims8
A laminated forming tool with a work contact surface, tool sides and a base made from resins and fillers for the cold forming of sheet metal, especially suitable for forming short runs of sheet metal parts with drop hammers, hydraulic presses or mechanical crank presses and the like which comprises:
- two layers of urethane on the tool sides and adjacent the contact surface;
- two layers of loose-knit cloth each impregnated into two more urethane layers;
- a first layer of thin, tight-knit cloth impregnated into another urethane layer;
- a second layer of thin, tight-knit cloth impregnated with aluminum filled resin and layered onto the first layer of thin, tight-knit cloth;
- three layers of thick, tight-knit cloth each impregnated with aluminum filled resin and layered onto the second layer of thin, tight-knit cloth;
- a fourth layer of thick, tight-knit cloth layered onto the other three layers of thick tight-knit cloth and impregnated with iron filled resin;
- a mass cast core comprising four parts aggregate mixed with one part iron filled resin formed onto the fourth layer of thick, tight-knit cloth, the core having a surface at the cloth and a free surface;
- a base affixed to a free surface of said core available for mounting purposes on a machine to press or form the sheet metal parts.
A method of making a laminated forming tool, with a contact surface, tool sides and a base, from resins and fillers, for the cold forming of sheet metal, especially suitable for forming short runs of sheet metal parts with drop hammers, hydraulic presses or mechanical crank presses and the like which comprises:
- affixing wood walls to an inside metal wood pattern such that the walls exceed the height of the peak on the pattern;
- sheet waxing the wood pattern to a thickness equal to the thickness of the metal to be formed;
- spraying the sheet wax surface with a release agent for communication with urethane;
- applying a first layer of urethane to the sheet wax surface and to the side walls;
- applying a second layer of urethane to the first layer when the first layer tacks;
- applying two layers of loose-knit cloth wetted into two new layers of urethane, butting the cloth into the edges of the surface created by the wood pattern;
- applying a first layer of thin, tight-knit cloth wetted into another layer of urethane onto the loose-knit cloth layer;
- applying a second layer of thin, tight-knit cloth wetted into a layer of aluminum filled resin onto the first thin, tight-knit layer;
- applying four layers of thick, tight-knit cloth each wetted into layers of aluminum resin, all four sequentially layered onto the second layer of thin, tight-knit cloth;
- wetting to the fourth layer of thick, tight-knit cloth with iron filled resin;
- filling the cavity formed by the side walls and the wood pattern with a mass cast core comprising four parts aggregate mixed with one part iron filled resin;
- curing said resin and
- attaching a base to the core for mounting the tool to a machine to press or form the sheet metal parts.
Dependencies are inferred from the claim text.