Fuse block with rejection feature

Abstract

A rejection-type fuse block is disclosed for use with Class CC cartridge-type fuses having ferrules at opposite ends, the ferrule at one end having a cap of smaller diameter than the ferrule. An insulated rejection collar having a rejection opening sized to allow the cap to pass therethrough while preventing passage of the ferrule is positioned between the fuse and an electrically conductive terminal. A leaf spring located at the end of the fuse opposite the cap end serves to axially press the fuse towards the insulated rejection collar and the cap into contact with the terminal. Fuse clips are provided for releasably securing the clip in proper position.

What is claimed is: 
     
       1. A rejection fuse block for a cartridge-type fuse having electrical contact elements at opposite ends, the contact element at one end including a cap, said cap having a smaller cross-sectional width than the adjacent portion of said fuse contact element; said fuse block comprising: (a) support means;   (b) electrically conductive means mounted on said support means and having a surface for contacting said cap at said one end of said fuse and making a first electrical connection with said fuse;   (c) electrically insulated rejection means colligated with said surface of said electrically conductive means, said rejection means having a rejection opening sufficiently large to pass said cap portion therethrough into contact with said electrically conductive means but smaller than the adjacent portion of said fuse contact element to prevent passage therethrough of said adjacent portion;   (c) means mounted on said support means for contacting the contact element at the opposite end of said fuse to make a second electrical connection with said fuse and for biasing said fuse towards said electrically insulated rejection means to force said cap into contact with said electrically conductive means; and   (d) dummy fuse clip means, said dummy clip means releasably retaining said one end of said fuse such that said cap is in alignment with said rejection opening in said rejection means, said dummy clip means being electrically insulated from said electrically conductive means.   
     
     
       2. The fuse block of claim 1 wherein said means for contacting the contact element at the opposite end of said fuse and for biasing said fuse towards said electrically insulated rejection means comprises a fuse clip for releasably retaining said contact element at the opposite end of said fuse and a leaf spring arranged to contact said contact element at the opposite end of said fuse and bias said fuse towards said electrically insulated rejection means. 
     
     
       3. The fuse block of claim 1 wherein said electrically conductive means having a surface for contacting said cap defines a pocket for receiving said cap therein to provide an electrical connection. 
     
     
       4. The fuse block of claim 2 wherein said leaf spring is composed of a material having a lower electrical conductivity characteristic than that of said fuse clip. .Iadd. 
     
     
       5.  A rejection fuse block for a cartridge-type fuse having electrical contact elements at opposite ends, the contact element at one end including a cap, said cap having a smaller cross-sectional width than the adjacent portion of said fuse contact element; said fuse block comprising: (a) support means;   (b) electrically conductive means mounted on said support means and having a surface for contacting said cap at said one end of said fuse and making a first electrical connection with said fuse;   (c) electrically insulated rejection means colligated with said surface of said electrically conductive means, said rejection means having a rejection opening sufficiently large to pass said cap portion therethrough into contact with said electrically conductive means but smaller than the adjacent portion of said fuse contact element to prevent passage therethrough of said adjacent portion;   (d) means mounted on said support means for contacting the contact element at the opposite end of said fuse to make a second electrical connection with said fuse and for biasing said fuse towards said electrically insulated rejection means;   (e) insulative guide means engageable with the adjacent portion to center said gap with said electrically conductive means; and   (f) said electrically conductive means further including retention means for providing a positive connection with the cap. .Iaddend. .Iadd.   
     
     
       6.  The rejection fuse block of claim 5 wherein said retention means includes a pocket in said surface of said electrically conductive means to positively connect the cap. .Iaddend. .Iadd.7. The rejection fuse block of claim 5 wherein said guide means includes an insulative stop engageable with the adjacent portion to limit the movement of the cap towards said support means and opposing insulative sides engageable with the adjacent portion for the centering of the cap. .Iaddend. .Iadd.8. A rejection fuse block for a cartridge-type fuse having a rejection terminal on one end and a non-rejection terminal at the other end, the rejection terminal having a cap with a smaller cross-sectional width than the adjacent portion of the rejection terminal, said fuse block comprising: an insulating support base;   a first electrically conductive means mounted on said support base and having an electrical contact for contacting the cap and making a first electrical connection with the fuse;   an electrically insulated rejection member adjacent said electrical contact, said rejection member having an opening sufficiently large to pass the cap therethrough into contact with said electrical contact but smaller than the adjacent portion of the fuse rejection terminal to prevent passage therethrough of the adjacent portion;   a second electrically conductive means mounted on said support base for contacting the non-rejection terminal of the fuse to make a second electrical connection with the fuse;   biasing means mounted on said support base for biasing the adjacent portion of the fuse rejection terminal against said electrically insulated rejection member;   insulative alignment means engaging opposite sides of the adjacent portion for centering the cap with said electrical contact; and   said electrical contact having a pocket to retain the cap. .Iaddend.   
     
     
        .Iadd. .  The rejection fuse block of claim 8 wherein said rejection 
     
     
        member is made of a dielectric material. .Iaddend. .Iadd.10.  The rejection fuse block of claim 8 wherein said second electrically conductive means is a fuse clip releasably retaining the non-rejection terminal. .Iaddend. .Iadd.11. The rejection fuse block of claim 8 wherein said opening is aligned with said pocket. .Iaddend. .Iadd.12. The rejection fuse block of claim 8 wherein said alignment means also retains the adjacent portion. .Iaddend. .Iadd.13. The rejection fuse block of claim 8 wherein said rejection member spaces the cap from said electrical 
     
     
        contact. .Iaddend. .Iadd.14.  The rejection fuse block of claim 8 wherein said insulative alignment means is made of metal and is electrically insulated from said first electrically conductive means. .Iaddend. 
     
     
        .Iadd.  .  The rejection fuse block of claim 14 wherein said metal alignment means acts as a heat sink to dissipate excess heat generated by the fuse. .Iaddend. .Iadd.16. The rejection fuse block of claim 8 wherein said biasing means is a leaf spring. .Iaddend. .Iadd.17. The rejection fuse block of claim 16 wherein said leaf spring is made of a material with an electrical resistance high enough to sufficiently reduce current flow therethrough to prevent stress relaxation in said leaf spring. .Iaddend. .Iadd.18. A fuseholder for a fuse having a rejection ferrule on one end and a non-rejection ferrule on the other end, the rejection ferrule having a cap arranged concentrically with the rejection ferrule and having a smaller diameter than the rejection ferrule, comprising: an insulative base;   an electrically conductive contact mounted and projecting from one end of said base and having a pocket for receiving and retaining the cap for making a first electrical connection with the fuse;   an electrically conductive fuse clip mounted and projecting from the other end of said base for receiving and retaining the non-rejection ferrule and for making a second electrical connection with the fuse;   an insulative member projecting from said base between said fuse clip and contact, said member having an opening aligned with said pocket for receiving the cap but not the rejection ferrule;   biasing means adjacent said fuse clip for axially biasing the rejection ferrule against said insulative member;   an insulative stop projecting from said base engageable with the rejection ferrule for limiting the movement of the rejection ferrule towards said base; and   centering means projecting from said base engageable with the rejection ferrule for centering the cap with said opening and contact. .Iaddend.