Printed circuit fuse assembly

• US 4,394,639 A
• Filed: 05/28/1981
• Issued: 07/19/1983
• Est. Priority Date: 12/18/1978
• Status: Expired due to Fees

• Current Assignee: James D. Mcgalliard
• Original Assignee: James D. Mcgalliard
• Inventors: McGalliard, James D.
• Primary Examiner(s): Broome, Harold
• Application Number:
  US06/267,704
• Time in Patent Office: 782 Days
• Field of Search: 337/4, 337/292, 337/297, 337/293, 337/283, 337/284, 361/104, 361/400, 361/404, 361/408, 361/431, 361/41, 340/638, 340/639, 174/68.5, 357/45, 357/41, 219/517
• US Class Current: 337/292
• CPC Class Codes: H01H 2085/266 with replacement of a fuse which is part of a printed circuit
• CPC Class Codes: H01H 85/046 Fuses formed as printed circuits
• CPC Class Codes: H01H 85/24 Means for preventing insertion of incorrect fuse
• CPC Class Codes: H01H 85/263 with spare printed circuit fuse
• CPC Class Codes: H01R 13/68 with built-in fuse
• CPC Class Codes: H05K 1/0263 High current adaptations, e.g. printed high current conductors or using auxiliary non-printed means; Fine and coarse circuit patterns on one circuit board H05K1/0293 takes precedence
• CPC Class Codes: H05K 1/0286 Programmable, customizable or modifiable circuits by programmable non-printed jumper connections H05K3/222

Abstract

A circuit fuse assembly comprising a plurality of fuse elements which are simultaneously formed using printed circuit or through hole plating techniques and including means for easily substituting a different one of the plural fuse elements when the in-circuit fuse element burns out due to an overload current condition. In the preferred embodiment, the fuse assembly is (a) integrally formed with the printed circuit of the fused electrical apparatus and (b) formed with a common electrical connection such that a single electrical bridge of solder or other means enables substitution of a replacement fuse element. Other embodiments of the present invention provide a restorable printed circuit fuse for use in standard fuse holders, in-line plug connectors, conventional three prong plug connectors, edison bases, and plug-in triple outlets.

Claims

1. In an electrical device having a printed circuit board including a plurality of electrical components, such as a resistor, capacitor, integrated circuit, or the like, which are combined to form a printed circuit, an improved fuse assembly comprising:

a conventional fuse having a predetermined current rating electrically connected to said printed circuit;

a thin printed fuse element having a predetermined fuse rating higher than said rating of said conventional fuse formed integral with said printed circuit and connected in series with said conventional fuse; and

said thin fuse element, upon burn-out, providing a permanent record on said circuit board of consumer mis-use of said electrical device caused by the bypass or improper replacement of said conventional fuse.

2. The improved fuse assembly of claim 1 wherein said thin fuse element is formed at the same time and with the same process as used to the manfacturing of said printed circuit.

3. In an electrical device having an electrical circuit including a plurality of electrical components, an improved fuse assembly comprising:

a current actuated first fuse having a predetermined current rating for protecting said electrical circuit, said first fuse accessible to the user of said electrical device to permit replacement thereof by said user;

a current actuated second fuse connected in series with the first fuse and measuring the same current, having a predetermined current rating higher than said current rating of said first fuse for protecting said circuit in the event of misuse of said electrical device by said user caused by the bypass or improper replacement of said first fuse;

said fuses connected in said circuit to interrupt power to said circuit upon burn-out of either of said fuses; and

said first fuse interrupting power to said circuit in preference to said second fuse for all overload current conditions of said electrical device.

4. In an electrical device having an electrical circuit including a plurality of electrical components, an improved fuse assembly, comprising:

first circuit interrupting means, for opening said circuit at a first predetermined current level to protect said circuit;

second circuit interrupting means connected in series with the first circuit interrupting means and measuring the same current, for opening said circuit at a second predetermined current level, higher than said first predetermined level, for protecting said circuit in the event of misuse of said first circuit interrupting means by a user;

said first circuit interrupting means opening said circuit in preference to said second circuit interrupting means for all overload current conditions of said electrical device, and

said first circuit interrupting means easily replaceable or resettable by said user, said second circuit interrupting means less easily replaceable or resettable by said user than said first circuit interrupting means to provide a record of misuse of said first interrupting means.