Electrostatic discharge protected fuse and fuse holder

• US 6,064,292 A
• Filed: 12/31/1998
• Issued: 05/16/2000
• Est. Priority Date: 12/31/1998
• Status: Expired due to Fees

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Pongracz, David J.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Vortman, Anatoly
• Application Number:
  US09/224,538
• Time in Patent Office: 502 Days
• Field of Search: 337/241, 337/222, 337/223, 337/224, 337/244, 337/251, 337/267, 337/268, 337/256, 337/199, 337/17, 337/19, 337/28, 337/221, 337/32
• US Class Current: 337/224
• CPC Class Codes: H01H 85/0095 Earthing means
• CPC Class Codes: H01H 85/303 Movable indicating elements
• CPC Class Codes: H01H 9/12 Means for earthing parts of switch not normally conductively connected to the contacts

Abstract

An electrostatic discharge ground path for a fuse installable in a fuse holder includes an area of metallization on at least one insulating surface of the fuse extending from an exposed surface of the fuse to a contact area within the fuse holder.

Claims

1. An electrical fuse assembly comprising:

a fuse including;

an insulative fuse body having an interior cavity and a face surface;

a pair of conductive fuse power contacts on the exterior of said fuse body remote from said face surface;

a fuse element in said fuse body cavity in contact with said fuse power contacts, said fuse element having an indicator portion arranged to be in a first location of said fuse body cavity when said fuse element is intact and in a second location of said fuse body cavity when said fuse element is destroyed as a result of excessive current therethrough; and

an indicator window on said fuse body face surface providing a view of said second location of said fuse body cavity; and

a fuse holder including;

an insulative fuse holder body having a cavity for receiving said fuse with said fuse body face surface being exposed;

a pair of conductive fuse holder power contacts secured inside said fuse holder body cavity for engagement with corresponding fuse power contacts when said fuse is installed in said fuse holder cavity; and

a pair of power terminal pins extending through said insulative fuse holder body into engagement each with a respective one of said fuse holder power contacts;

WHEREIN THE IMPROVEMENT COMPRISES;

a conductive fuse holder ground contact inside said fuse holder body cavity;

a ground terminal pin extending through said fuse holder body into engagement with said ground contact;

a conductive fuse ground contact on the exterior of said fuse body remote from said face surface and engaging said fuse holder ground contact when said fuse is installed in said fuse holder cavity; and

an area of metallization on the exterior of said fuse body, said area of metallization covering a portion of said fuse body face surface without covering said indicator window, said area of metallization extending into contact with said fuse ground contact.

2. An electrical fuse assembly comprising:

a fuse holder having at least one ground terminal; and

a fuse having a pair of power contacts and at least one ground contact, the fuse being disposable within said fuse holder such that the at least one ground terminal engages with the at least one ground contact, wherein the fuse has a fuse body within which is a fuse element visible through a window on the fuse body.

3. The electrical fuse assembly of claim 2 wherein said fuse further has an area of metallization permanently affixed on a surface of said fuse extending from the at least one ground contact.

4. The electrical fuse assembly of claim 2 wherein the fuse holder has at least one conductive trace extending from the at least one ground terminal to a fuse holder ground contact.

5. The electrical fuse assembly of claim 4 wherein the fuse ground contact engages with the fuse holder ground contact when the fuse is disposed within the fuse holder.

6. The electrical fuse assembly of claim 2 wherein the fuse further has an area of metallization permanently affixed on an external surface of the fuse body extending from the at least one ground contact, the area of metallization not covering the window.

7. The electrical fuse assembly of claim 2 wherein an electrical ground path is formed by the engagement of the at least one ground terminal with the at least ground contact, which ground path creates a path of least resistance for an electrostatic discharge applied to the fuse.