Fuseholder - Patent Review 5444428

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This invention relates to a fuseholder adapted for snap-on connection to one or more electrical conductors so that an otherwise unfused load may be adequately protected by a fuse.

BACKGROUND OF THE INVENTION

The use of male adapter plugs, which are inserted into receptacles powered by a vehicle battery or other power system, is being extended to new applications requiring increased current loads. Adapter plugs are available in the prior art both with built-in integral fuses and also without fuses. In many adapter-plug designs having integral fuses, only fuses in the range of three amperes or less may be used; however, load currents can extend to fifteen amperes or more for some appliances powered by adapter-plug line cords.

The prior art includes an automobile in-line fuseholder which receives and encloses a standard automobile flat-blade insert fuse. This fuseholder can be used with an electrical conductor connected to an adapter plug. However, since the fuseholder is molded on and over the line cord, the adapter plug must be disassembled in order to establish a fused connection with the fuseholder.

SUMMARY OF THE INVENTION

Accordingly, a principal object of their invention is to provide a fuseholder which can be easily applied to an unfused conductor or a pair of unfused conductors.

Another object of their invention is to provide a fuseholder for an unfused load which can be applied to a line cord attached to an adapter plug, a receptacle or other electrical device without requiring disassembly of the plug, receptacle device or load.

Another object is to provide an in-line fuseholder which can be snapped onto a line cord without disturbing any input or output accessory connected to the ends of the line cord.

A preferred embodiment of the fuseholder of this invention comprises an integral single-piece housing for receiving portions of a pair of in-line electrical conductors which may be connected to a non-fused electrical adapter plug. One conductor of the pair is severed within the holder to form an open connection until the connection is completed by a flat-blade insertion fuse. A pair of female electrical terminals is located within the fuseholder with each terminal connected to a different end of the severed conductor. The fuseholder has a foldable "clam-shell" housing formed by a pair of foldable cover sections joined by a centrally disposed hinge section. The housing is opened to receive the in-line electrical conductor pair, or alternatively is folded to a closed position to create a partially closed cavity which forms a fuse-insert access opening opposite the hinge section. Any inserted flat-blade fuse is connected in series with the conductor terminals to complete a fused conductor connection through the fuseholder to the adapter plug.

DESCRIPTION OF THE DRAWINGS

In order that all of the structural features for attaining the objects of this invention may be understood, reference is made to the accompanying drawings in which:

FIG. 1 is an isometric view of a capped fuseholder of this invention engaging a pair of twin conductors;

FIG. 2 is a view related to FIG. 1 which shows the fuseholder cap disengaged from the fuseholder housing to provide access to a flat twin-blade fuse;

FIG. 3 is an exploded view which shows the fuseholder housing in an unfolded position, the fuseholder cap assembly disengaged from the fuseholder housing, and a pair of twin conductors in which one conductor is prepared with a set of female electrical terminals for receiving a flat blade fuse;

FIG. 4 a plan view which shows the internal construction of an unfolded fuseholder housing;

FIG. 5 is a side elevation view of the fuseholder housing of FIG. 4;

FIG. 6 a plan view which shows the external construction of the folded fuseholder housing;

FIG. 7 is a section view taken along line 7--7 of FIG. 4;

FIG. 8 is a section view taken along line 8--8 of FIG. 4;

FIG. 9 is a section view taken along line 9--9 of FIG. 4;

FIG. 10 is a section view taken along line 10--10 of FIG. 4;

FIG. 11 is a section view taken along line 11--11 of FIG. 4;

FIG. 12 is a view related to FIG. 1 which shows the side of the fuseholder housing opposite to that shown in FIG. 1;

FIG. 13 is a side elevation view of the fuseholder housing of FIG. 12;

FIG. 14 is a section view taken along line 14--14 of FIG. 13 which shows the internal connection of a flat fuse to a pair female terminals fixed to a single line conductor of a pair of twin conductors engaged by the fuseholder housing;

FIG. 15 is a section view taken along line 15--15 of FIG. 14;

FIG. 16 is a section view taken along line 16--16 of FIG. 14;

FIG. 17 is a section view taken along line 17--17 of FIG. 14; and

FIG. 18 is a modified section view taken along line 18-18 of FIG. 14 in which the fuse is removed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Fuseholder 1 of this invention engages a pair of twin conductors 2 and 3 in such a manner that flat-blade insert fuse 4 completes a series electrical connection with conductor 2 (FIGS. 1, 2 and 3). Conductor 2 is severed (FIG. 3), and the conductor insulation is removed for a short length sufficient to receive female electrical terminals 5 and 6. Terminals 5 and 6 are housed within fuseholder housing 7 (FIG. 14). These terminals are located within the fuseholder housing to receive fuse blades 8 and 9 when the fuse is inserted in end access opening 10 formed by folding fuseholder housing 7 (FIGS. 1, 2, 12, 15 and 16).

Fuseholder 1 comprises two separable parts, namely fuseholder housing 7 and end cap assembly 11 (FIGS. 1, 2, 3, 12, 13 and 14). Both parts are fabricated from a flexible plastic, such as polypropylene, because each part has an integral hinge section that is required to fold. In particular, housing 7 comprises a fuse and conductor retaining cover section 12 and a locking cover section 13 integrally joined by a hinge section 14. Hinge section 14 is formed with a series of five rectangular hinge holes 15 which facilitate folding (FIG. 3). As is best shown in FIG. 10, hinge section 14 is also reduced in wall thickness in the areas adjacent hinge holes 15 to further promote ease of folding. End cap assembly 11 includes a cap 16 integrally joined to flexible plastic cap hinge 17 which in turn is integrally attached to rectangular ring 18 (FIGS. 1 and 3). Ring 18 is attached to housing 7 by folding housing 7 as is shown in FIGS. 1 and 2 and slipping the ring over the end of the housing until the short bands of ring 18 are captured by the pair of catch sets 19 and 20 (FIGS. 2, 3, 4, 5, and 6).

When housing 7 is folded, projecting lock finger 21, which is supported on an inside surface of cover section 13 (FIGS. 2, 3, 4 and 5), mates with lock hole 22 to lock cover sections 12 and 13 in the folded position. Thereafter, the placement of ring 18 in catch sets 19 and 20 further assures retention of housing 7 in the folded position.

The ends of cover sections 12 and 13 are formed with notches 23 and 24, respectively (FIGS. 3, 4 and 6). These notches expose a portion of flat fuse 4 so that the fuse can be easily inserted and removed manually frown fuseholder 1. Additionally, a set of four projecting finger grips 25 are formed on an outer surface of cover sections 12 to facilitate manual handling of fuseholder 1.

A set of partially cylindrical conductor passage sections 26, 27, 28, 29, 30 and 31 (FIGS. 3, 10 and 14) are formed on the inside of cover sections 12 and 13. The severed left end of conductor 2 (as viewed in FIGS. 3 and 14) is received by passage sections 26 and 30; and the severed right end of conductor 2 is received by passage sections 27 and 31. Through conductor 3 is received by through passage sections 28 and 29. Four sets of strain-relief barbs 32, 33, 34 and 35 (FIG. 3) project from the inside walls of passage sections 26, 30, 27 and 31, respectively. These barbs engage the insulation cover of severed conductor 2 to assist in locking the separated internal ends of this conductor in place relative to fuseholder 1 and to relieve any possible external pulling force that might otherwise be applied to terminals 5 and 6. No strain-relief barbs are located within through passage sections 28 and 29.

A terminal separating block 36 is supported on the inside surface of cover section 12 (FIGS. 3 and 4). When housing 7 is folded, the projection of block 36 separates closed passage sections 26-30 from closed passage sections 27-31 to assist in separating terminals 5 and 6 from one another to prevent an electrical short. The projection of block 36 is restricted, however, from obstructing closed through passage sections 28-29. The mating passage sections formed by folding housing 7 establishes one through passage for conductor 3, and an obstructed passage for conductor 2 which leads into divided terminal access passage 44-45.

A compartment 37 for receiving terminal 5 is formed by walls 38 and 39 and rib 40 when housing 7 is folded (FIGS. 3, 4 and 14); and compartment 41 for receiving terminal 6 is similarly formed by walls 42 and 43 and rib 40. The wire-containing stems of terminals 5 and 6 are received by divided terminal access passage 44-45. This passage leads to compartments 37 and 41. Terminal access passage 44-45 is divided by separating block 36 (FIG. 4). Access passage 44-45, as well as compartments 37 and 41, are further defined by end-wall reinforcing ribs 46 and 47 (FIG. 4). Reinforcing ribs 46 and 47 reinforce ends walls 38, 39, 42 and 43 to prevent a pulling stress on terminals 5 and 6 exerted either by conductor 2 or fuse 4 from displacing the terminals from their respective compartments.

Sidewalls 48 and 49 of cover section 12 (FIGS. 3 and 8) support a pair of locking tabs 50 and 51. When housing 7 is folded, tabs 50 and 51 engage edge recesses 52 and 53 formed on the sides of cover section 13 to further assure locking.

It should be understood that the preferred embodiment of the invention can be modified without departing from the scope of the invention.

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