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US 4,067,103 AGranted
Method of making a plug-in fuse
AssigneeLittelfuse, Inc.
InventorAllen L. Ciesmier
Life of this patent
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AssigneeLittelfuse, Inc.
InventorAllen L. Ciesmier
Estimating the term…
A method for making a plug-in fuse assembly like that disclosed and claimed in U.S. Pat. No. 3,909,767, granted Sept. 30, 1975 for Miniature Plug-In Fuse having different desired fuse ratings. The method comprises the steps of providing a strip of fuse metal which is initially preferably provided throughout its length with a continuous longitudinally extending portion of reduced thickness having a fixed thickness dimension and from which fuse link portions of fuse elements are to be stamped. Various selected areas of the strip, those which preferably are not the portions of reduced thickness and from which the terminal portions of the fuses are to be formed, are covered with a non-oxidizable conductive coating, preferably tin plating. The strip of fuse metal is then blanked to form longitudinally spaced still interconnected plug-in fuse element-forming sections each comprising spaced terminal blade portions and current-carrying extensions thereof formed from the thicker tin plated portions of the strip and a fuse link extending between said current-carrying extensions and formed from the unplated portions of the strip. The interconnecting un-plated fuse link portions of fixed reduced thickness dimension are arranged in desired locations and provided with desired configurations, including width and length dimensions, to provide the different desired fuse ratings. The method may include inserting over the end fuse-forming section of the strip either before or after it is severed from the strip a housing made of insulating material, with the current carrying extensions and the interconnecting fuse link portion of each plug-in fuse element within the housing and with the pair of terminal blade portions thereof extending outwardly from the housing.
A method of making a plug-in fuse element including a plate-like body of an ambient air oxidizable fuse metal having a pair of spaced confronting generally parallel terminal blade portions to be received by pressure clip terminals or the like, current-carrying extensions at the inner ends of said pair of terminal blade portions and a fuse link portion interconnecting the current-carrying extensions, the method comprising the steps of providing a strip of fuse metal having longitudinally spaced blank portions from which individual plug-in fuse elements are to be formed, each blank portion having corresponding portions spaced transversely of the length of the strip from which said fuse link portions, on the one hand, and at least said terminal blade portions, on the other hand, of a plug-in fuse element is to be formed, providing bands of non-oxidizing conductive coatings on the opposite faces of said fuse metal strip which cover at least the terminal blade-forming portions of said blank portions of said strip, the fuse link-forming portions thereof being free of such coatings, sequentially advancing the strip of fuse metal, and blanking said strip in each of said blank portions thereof to form said pairs of terminal blade portions coated with said conductive non-oxidizing coating, said current-carrying extensions interconnected by a fuse link portion free of said non-oxidizing coatings.
A method of making a plug-in fuse element including a plate-like body of an ambient air oxidizable fuse metal having a pair of spaced confronting generally parallel terminal blade portions to be received by pressure clip terminals or the like, current-carrying extensions at the inner ends of said terminal blade portions and a fuse link portion interconnecting the current-carrying extensions, the method comprising the steps of providing a blank of fuse metal having a portion from which the fuse link portion of the fuse element is to be formed and other portions from which said terminal blade portions and current-carrying extensions thereof are to be formed, the blank being thicker than desired in the areas thereof from which said fuse link is to be formed, initially coating all exposed surface areas of said blank with a non-oxidizing conductive coating, and then reducing the thickness of said blank from both sides thereof in the fuse link-forming area thereof, to produce thereat fuse metal of said desired thickness and to remove said conductive non-oxidizing coatings therefrom, and blanking said blank of fuse metal to form a fuse link of desired resistance value from said reduced thickness fuse link-forming portions of the blank and to form said terminal blade portions and current-carrying extensions thereof in the other portions of the blank.
Dependencies are inferred from the claim text.