{"product_id":"1930s-duro-metal-products-patent-litigation-archive","title":"1930s Duro Metal Products Patent Litigation Archive","description":"\u003cp\u003ec. 1920s-1950s; Duro Metal Products Company - Chicago, IL\u003cbr\u003e\n\u003cbr\u003e\nExtensive archive of patent-related materials centered around mechanical locking and tool-adjacent innovations, including diagrams, typed legal correspondence, engineering drawings, and original patent documentation. The group appears to document Duro Metal Products' involvement in a dispute and\/or licensing negotiations surrounding inventions attributed to Johnson Lock Co., with particular emphasis on automotive locking devices, torque-related mechanisms, and associated tooling applications.\u003cbr\u003e\n\u003cbr\u003e\nThe archive includes multiple large-format patent sheets with detailed technical illustrations, annotated diagrams, and early 20th century filing information, alongside mid-century legal correspondence from Chicago-based patent attorneys. Several envelopes and mailing labels remain intact, addressed directly from Duro Metal Products Co., referencing patent claims, filings, and technical evaluations. Also present are blueprint-style drawings, typed letters on onion-skin paper, and supporting documentation referencing foreign patents and structural claims-suggesting a broader international patent strategy or defense. The material spans decades of development and review, capturing both the invention phase and later legal positioning.\u003cbr\u003e\n\u003cbr\u003e\nShows heavy wear consistent with archival use, including edge tearing and creasing to envelopes, toning and discoloration throughout, folded and worn corners, and general handling wear. Contents remain largely intact with legible text and drawings.\u003cbr\u003e\n\u003cbr\u003e\n9\" W x 14\" H each\u003cbr\u003e\n\u003cbr\u003e\nMM - C-20022 - 040226\u003c\/p\u003e\n\n\u003cp\u003eFor information regarding shipping, please visit our Terms \u0026amp; Conditions page \u003ca class=\"GeneratedLink\" href=\"https:\/\/industrialartifacts.net\/pages\/shipping\" target=\"_blank\"\u003ehere\u003c\/a\u003e.\u003c\/p\u003e\n","brand":"Industrial Artifacts","offers":[{"title":"Default Title","offer_id":43963621965867,"sku":"C-20022","price":325.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0194\/8170\/files\/6270bea9-f50f-5ff5-b302-88bc91610f6a.jpg?v=1776877186","url":"https:\/\/industrialartifacts.net\/products\/1930s-duro-metal-products-patent-litigation-archive","provider":"Industrial Artifacts","version":"1.0","type":"link"}