Patent Publication Number: US-4836802-A

Title: Sealed fuse holder

Description:
BACKGROUND AND SUMMARY 
     The present invention arose during development efforts directed toward providing a sealed fuse holder particularly for marine applications, and particularly adapted to be mounted in an aperture in a mounting panel and subject to moisture and to fuel vapor. 
     In marine applications, there is a need to provide a fuse holder which is both moisture-proof and explosion-proof. The present invention addresses and and solves this need. The invention provides an improved fuse holder for blade-type fuses, particularly for the above noted requirements in marine applications. 
     A known fuse holder is shown in U.S. Pat. No. 4,560,227, incorporated herein by reference. A known blade-type fuse is shown in U.S. Pat. No. 3,909,767, incorporated herein by reference. The noted fuse holder is neither moisture-proof nor explosion-proof. The fuse holder is open at the front and rear, and allows entry of moisture and fuel vapor to the area of the electrical contact surfaces and to the area of the fusible link. Moisture degrades the electrical contact surfaces. Fuel vapor in the area of the fusible link presents an explosion hazard. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a sealed fuse holder in accordance with the invention, with a known blade-type fuse separated therefrom. 
     FIG. 2 is a sectional view taken along line 2--2 of FIG. 1. 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 1. 
     FIG. 4 is a front elevation view of the fuse holder of FIG. 1. 
     FIG. 5 is an enlarged sectional view of a portion of FIG. 3, prior to insertion of the fuse. 
     FIG. 6 is a view like FIG. 5, but showing insertion of the fuse. 
     FIG. 7 is a sectional view taken along line 7--7 of FIG. 6. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows a sealed fuse holder 10 comprising a resilient molded rubber electrically insulating receptacle 12 adapted to receive a fuse 14 comprising a hard plastic fuse body 16 having a pair of spaced parallel male blade terminals 18 and 20 extending therefrom. Fuse 14 is known in the art, and is shown in the above noted incorporated patents. Rubber receptacle 12 is molded in place between and around a pair of spaced electrically conducting female terminal-receiving clips 22 and 24. These clips are shown in above incorporated U.S. Pat. No. 4,560,227. Receptacle 12 has a front face 26 with an opening 28 therein defining a cavity 30 extending rearwardly therefrom, and having a back wall 32, FIGS. 2 and 5, spaced rearwardly from front face 26, and having side walls 24, 26, FIGS. 3 and 5, extending from front face 26 at opening 28 rearwardly to back wall 32. The female terminal-receiving clips 22, 24 extend rearwardly from back wall 32 within and sealed by the molded rubber receptacle 12 and receive respective blade terminals 18, 20 inserted rearwardly thereinto. 
     Receptacle 12 includes an integral molded rubber resilient rib 38 extending along the side walls of the cavity and engaging and being resiliently deformed by fuse body 16 in sealing relation. Cavity 30 is sealed from the front by integral molded rubber rib 38, and is sealed from the rear by the rubber receptacle 12 molded between and around female terminal-receiving clips 22 and 24. Resilient rubber rib 38 prevents entry of moisture and fuel vapor into cavity 30 rearwardly of the rib. Rib 38 engages fuse body 16 rearwardly of front face 26 and forwardly of back wall 32 and seals the space between rib 38 and back wall 32 against entry of moisture and fuel vapor from front face opening 28. 
     Fuse body 16 is a generally flat planar member with coplanar blade terminals 18 and 20 in the plane of the fuse body and separated by a fusible link 40 therebetween, FIG. 2. The fuse body has opposite generally planar sides 42, 44, FIG.6, with a blade terminal such as 20 extending planarly therebetween and extending rearwardly thereof. The resilient rib 38 includes portions 38a and 38b, FIGS. 3, 5, 6, engaging each of the opposite generally planar sides 42 and 44 of fuse body 16 and deformed thereby, FIG. 6. The opposite generally planar sides 42 and 44 of fuse body 16 have rear ends 46, 48, FIG. 6, abutting against back wall 32. Fusible link 40 is forward of rear ends 46 and 48 and is sealed by back wall 32 engaging rear ends 46, 48 of the noted opposite generally planar sides of fuse body 16. 
     The present invention advantageously provides a sealed fuse holder particularly adapted for marine applications and particularly adapted to be mounted in an aperture 50, FIGS. 2 and 3, in a mounting panel 52 having a front side 54 and a back side 56 subject to moisture and fuel vapor. The first sealing means provided by integral molded rubber resilient rib 38 at rib portions 38a and 38b provides sealing against moisture and fuel vapor from the front. The second sealing means provided by the integral molded rubber receptacle 12 between and around female terminal-receiving clips 22 and 24 and also including back wall 32 provides sealing against moisture and fuel vapor from the rear. These first and second seals provide moisture-proof and explosion-proof sealing. The remaining portion of the front seal is provided by hard plastic channel portions 58 and 60 of fuse body 16, which are known in the art, received in channel grooves 62 and 64 of resilient molded rubber receptacle 12, which grooves are molded to conform to and be sealed by channels 58 and 60. 
     Fuse holder 10 is installed rearwardly through aperture 50 of panel 52 until circumferential groove 66 around the exterior of receptacle 12 is received in aperture 50 in snap-in relation. During this insertion, shoulder portion 68 of receptacle 12 is slightly compressed until it is rearward of aperture 50. Insertion is stopped by outer peripheral flange 70 around front face 26 engaging the front side 54 of panel 52. The engagement of aperture 50 of panel 52 by groove 66 of receptacle 12, and the engagement of back side 56 of panel 52 by shoulder 68 of receptacle 12, and the engagement of front side 54 of panel 52 by flange 70 of receptacle 12 seals any communication through aperture 50 between the back side 56 and the front side 54 of the panel. 
     It is recognized that various equivalents, alternatives and modifications are possible within in the scope of the appended claims.