Method of making a miniature plug-in fuse

• US 4,056,884 A
• Filed: 06/08/1976
• Issued: 11/08/1977
• Est. Priority Date: 02/08/1975
• Status: Expired due to Term

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Aryamane, Avinash P., Williamson, Harold L.
• Primary Examiner(s): DiPalma, Victor A.
• Application Number:
  US05/693,937
• Time in Patent Office: 518 Days
• Field of Search: 29/623, 29/DIG. 15, 29/414, 29/417, 339/62, 339/147 P, 339/208, 337/198, 337/187, 337/201, 337/206, 337/255, 337/262, 337/263, 337/264, 337/293, 337/295, 337/297, 113/119, 113/116 P
• US Class Current: 29/623
• CPC Class Codes: H01H 69/02 Manufacture of fuses
• CPC Class Codes: H01H 85/0417 with parallel side contacts
• CPC Class Codes: Y10T 29/49107 Fuse making
• CPC Class Codes: Y10T 29/49798 Dividing sequentially from leading end, e.g., by cutting or breaking

Abstract

A method comprises the steps of providing a blank containing a pair of laterally spaced coplanar terminal forming blade portions which are interconnected by a transverse rigid web, coplanar current carrying extensions thereof and an interconnecting relatively fragile fuse-forming link inserting around the blank a housing made of insulating material with the current carrying extensions of the blank and the interconnecting fuse-forming link preferably within the housing and with the pair of terminal blade portions of the blank and the transverse web on the outside of the housing, securing said blank to the housing so the housing rigidly interconnects and supports the current carrying extensions, and blanking the exposed transverse web interconnecting the terminal blade portions.

Claims

1. A method of making a plug-in fuse element comprising a pair of juxtaposed laterally spaced generally parallel terminals to be received by pressure clip terminals or the like, the terminals having current-carrying extensions at the inner end portions thereof which are to be interconnected by a fuse link, said method comprising:

providing a sheet-like body of fuse metal, and blanking said sheet-like body of fuse metal to form parallel mutually coplanar juxtaposed laterally spaced terminal forming blade portions, current-carrying extensions at the inner end portions of the terminal forming blade portions thereof and a fuse-forming link portion interconnecting said current-carrying extensions, said fuse-forming link portion being substantially smaller in cross-sectional area than the other portions of the blanked body of fuse metal.

2. The method of claim 1 wherein prior to said blanking step the body of fuse metal is reduced in thickness in the areas thereof in which said fuse-forming link portion is to be formed so such portion is both narrower in width and thinner in thickness than the terminal-forming blade portions and current-carrying extensions.

3. The method of claim 2 wherein said fuse-forming link portion of the body of fuse metal extends transversely between said current-carrying extension of the terminal-forming blade portions thereof.

4. The method of claim 1 wherein there is applied over the blanked body of fuse metal a housing made of insulating material which is open at the inwardly facing side thereof for the full width of the plug-in fuse element so as initially to receive said plug-in fuse element therethrough when it is assembled therewith, and said housing and plug-in fuse element are anchored together after assembly.

5. The method of claim 1 wherein there is applied immediately over said plug-in fuse element a housing made of insulating material including closely spaced side walls, which closely envelope said current-carrying extensions of said plug-in fuse element.

6. The method of claim 5 wherein said housing and plug-in fuse element are interlocked by projections formed in said housing which enter apertures in the plug-in fuse element.

7. The method as defined in claim 6 wherein the insulating body is ultrasonically heated where it is staked into the interlock openings in the blank.

8. A method of making a plug-in fuse assembly comprising a plug-in element including a pair of terminals to be received by pressure clip terminals or the like, a fuse-forming link forming at least part of an interconnection between the terminals, said method comprising the steps of providing a blank of fuse metal where the blank is initially provided with a portion of reduced thickness, and blanking said blank to form a pair of terminals which are at least in part interconnected by a fuse-forming link portion formed in said portion of reduced thickness, so that the fuse-forming link portion of the blank is of much less thickness and cross-sectional area than the terminals.

9. The method as defined in claim 8 wherein the portion of reduced thickness of the blank of fuse metal is reduced by milling.

10. The method as defined in claim 8 wherein the portion of reduced thickness of the blank of fuse metal is reduced by milling and subsequent squeezing.

11. The method of making a plug-in fuse element including a pair of spaced confronting generally parallel terminals to be received by pressure clip terminals or the like, current-carrying extensions at the inner end portions of the pair of terminals and a fuse-forming link interconnecting the current-carrying extensions, said method comprising the steps of providing a continuous strip of conductive material, sequentially advancing the continuous strip, blanking said continuous strip to provide at spaced intervals in said strip longitudinally interconnected blanks each comprising a pair of spaced confronting generally parallel terminal portions extending longitudinally along the strip, and a pair of current-carrying extensions of the terminal portions extending longitudinally along the strip and providing also a fuse-forming link extending laterally of the strip and between each pair of said current-carrying extensions thereof, and severing end blanks from the strip.

12. The method of claim 11 wherein there is added between the current-carrying extensions of each blank rigid insulating means which forms a rigid interconnection therebetween, with the pair of terminals of each blank extending from the insulating means.

13. The method of claim 11 wherein the insulating means applies to each blank, forms also a housing enclosing the fuse-forming link thereof.

14. The method of claim 11 wherein said continuous strip is made of fuse metal so that said fuse-forming link as well as said each pair of terminals are formed when the strip is blanked, and each severed end blank forms a one piece all fuse metal body.

15. The method as defined in claim 14 wherein the sequentially advanced continuous strip of fuse metal before it is blanked is initially provided with portions of reduced thickness within which the fuse-forming links are formed so that, when the strip of fuse metal is blanked, the interconnecting fuse-forming links of the longitudinally interconnected blanks are of less thickness than the spaced terminals thereof.

16. The method as defined in claim 15 wherein the portion of reduced thickness in the strip of fuse metal are arranged at longitudinally spaced intervals in the strip.

17. The method of making a plug-in fuse assembly comprising a plug-in element having a pair of spaced terminals to be received by pressure clip terminals or the like, current-carrying extensions at the inner end portions of the pair of terminals and a fuse link between said current-carrying extension, and a housing of insulating material, said method comprising the steps of providing a continuous strip of fuse metal, sequentially advancing the continuous strip, blanking said continuous strip after it is sequentially advanced to provide at spaced intervals in said strip longitudinally interconnected blanks each containing a pair of spaced terminals, current-carrying extensions at the inner end portions of the pair of terminals and a fuse link between said current-carrying extension, severing the end blanks from the strip, and applying and securing over each end blank a housing of insulating material with the current-carrying extensions and the fuse link of the end blank within the housing and with the pair of terminals of the end blank extending outwardly from the housing, said housing closely enveloping said current-carrying extensions but being spaced from said fuse link.

18. The method as defined in claim 17 wherein applying the housing over the end blank occurs before severing said end blank from the strip.

19. A method of making a plug-in fuse element comprising a plug-in element including a pair of spaced confronting generally parallel terminal forming blade portions to be received by pressure clip terminals or the like, a pair of confronting current carrying extensions projecting longitudinally from the inner ends of the pair of terminal forming blade portions and a fuse-forming link portion interconnecting the current carrying extensions, said method comprising the steps of providing a sheet-like blank of fuse metal initially provided within the longitudinal margins thereof with a portion of reduced thickness, blanking said blank including at least said portion of reduced thickness to leave a pair of spaced confronting general parallel terminal forming blade portions to be received by pressure clip terminals or the like, confronting current carrying extensions projecting longitudinally from the inner end portions of said terminal forming blade portions, and a fuse-forming link formed in said portion of reduced thickness extending between the confronting portions of said current carrying extensions.