Fuse Switch With Plural Positionable Fuse Elements

The present invention relates to an improved fuse switch including a rachet wheel rotated to a desired angle by a drive bar or link mounted pawl. The switch also includes a fuse having eight or more radiating arms, the fuse being controlled by the rachet wheel to change the fuse position when one pair of opposing arms has burned through. The switch of the invention is also provided with an indication lamp connected in parallel with the power and controlled by means of a relay to to provide light for the operator to repair the fuse when the fuse has burned down due to overload of equipment on the circuit.

One object of the present invention is to facilitate assembly and disassembly of a fuse switch without the use of a screwdriver.

Another object of the invention is to provide means carried by a switch, as for example a rachet wheel, for changing an internally carried fuse, to thus save repair time.

Yet another object of the invention is to provide a fuse switch with an indication lamp so that repair during operation at night can be made without providing additional lighting equipment.

The present invention will now be described in greater clarity and specificity with reference to the following drawings in which:

FIG. 1 is a top plan view of a preferred fuse element of the present invention;

FIG. 2 is a cross-sectional view of the FIG. 1 fuse taken along section line 2--2;

FIG. 3 is a top plan view of the washer of the assembled switch of FIG. 18;

FIG. 4 is a cross-sectional view of the FIG. 3 washer taken along section 4--4;

FIG. 5 is a top plan view of the rotating cylinder of the assembled switch of FIG. 18;

FIG. 6 is a front cross-sectional view of FIG. 5 taken along section line 6--6;

FIG. 7 is a front cross-sectional view of the plunger of FIG. 18;

FIG. 7a is a partial elevational view of the plunger of FIG. 7 when rotated 90.degree.;

FIG. 8 is a top view of the rachet wheel of FIGS. 17 and 18;

FIG. 9 is a front cross-sectional view of FIG. 8 taken along section line 9--9;

FIG. 10 is a front elevational view of the drive bar or link shown in FIG. 17;

FIG. 11 illustrates, in section, the rotating disc of FIGS. 12 and 17;

FIG. 12 is a bottom plan view of the rotating disc of FIG. 11;

FIG. 13 is a top view of the top section or cover shown in FIG. 18;

FIG. 14 is a cross-sectional view of the top section cover taken along section line 14--14 in FIG. 13;

FIG. 15 is a bottom view of the top cover of FIG. 14;

FIG. 16 is a schematic of the circuit of the switch of the present invention;

FIG. 17 is a bottom view of the present invention after being assembled; and

FIG. 18 is a cross-sectional view on section line 18--18 of FIG. 17.

As shown in the drawings, the present invention comprises a bottom section or cover 1, rotating stand 2, top cover 3, and rachet wheel 33.

Noting FIG. 18, the bottom section or cover 1 is made of insulating material, and includes a top section or surface having two cavities 11,11 for insertion thereinto of coil springs 12,12 and copper contacts 13A,13B, respectively. The contacts 13A,13B are urged upwardly to a point slightly above the bottom cover surface by coil springs 12,12 in order to maintain tight contact with the fuse 25 when the bottom cover 1 is attached to the top cover 3. Each cavity 11 has an aperture 15 at its bottom to accomodate free movement of vertically disposed copper rod 14 therethrough. Copper rod 14 connects a secondary circuit including a a horizontally disposed bar 16 with a vertically displaceable plunger 17. The middle of the bar 16 is fixed by ordinary means to support bracket 18, with coil spring 19 being positioned between the support bracket 18 and the bar 16 to resiliently urge the end of bar 16 which is connected to plunger 17 upwardly, thus driving plunger 17. Thus contact 13A is urged downwardly so that electric shock is avoided when the fuse is assembled. Contact 13A is connected with a power source by a power cable (see FIG. 16), while contact 13B is connected with equipment powered by the circuit. Plunger 17, located between the two contacts, is connected in parallel with a relay 19A and an indication lamp 21A.

The plunger 17 includes an inner copper conductor 17A, an outer conductive copper cylinder 17B and insulating material 17C separating the inner conductor and the cylinder. At its top end, plunger 17 has a recess 20 for insertion of the bottom of the indication lamp 21A which is fixed within the top cover 3.

As can be seen in FIG. 18, the rotating stand 2 comprises the rotating disc 21 and rotating cylinder 22 both coaxial with plunger 17 on which indication lamp 21A is carried. Referring to FIGS. 11 and 12, the rotating disc 21 includes eight apertures or depressions 23 separated by partitions or lands 24. Each depression receives one of the arms of the fuse 25 shown in FIGS. 1 and 2. Thus when the disc 21 is rotated, each arm of the fuse 25 is followed by a respective partition 24. Beneath fuse 25 is a washer 25A provided for the support of the fuse to avoid chipping away thereof as it is burned down. The center of the rotating disc 21 is provided on one side with a cross-shaped key 26 which may be inserted into the cross-shaped keyway 27 in the rotating cylinder 22, and on its other surface is provided with balls 28 to increase the likelihood that disc 21 will rotate uniformly. Rotating cylinder 22 (note FIGS. 5 and 6) includes at one end a cross-shaped keyway 27 for insertion thereinto of the rotating disc key 26, and under that end has external threads 29 for fixing it within the rachet wheel 4. Both rotating disc 21 and rotating cylinder 22 have aligned apertures--the rotating cylinder including aperture 30 extending longitudinally therethrough and preferably being of circular cross-section, and the rotating disc including aperture 30' extending longitudinally therethrough and also being preferably of circular cross-section--so that free movement of the plunger 17 therethrough may be accomodated.

The top cover 3, shown in FIGS. 13, 14 and 15, is made of transparent plastic material, having recess or slot 31 and indication lamp cavity 32 for receipt therein of the indication lamp 21A. Internal and external threads at the cavity 32 and lamp 21A, respectively, permit the lamp to be fixed within the cavity. Top cover 3 is attached to the bottom cover 1 by engaging slot 31 with flange 32, respectively.

The rachet wheel 4, as shown in FIGS. 8 and 9, includes rachet notches or teeth 33 at its periphery, and an internal thread 34 which engages with the external thread 29 of the rotating cylinder 22 by ordinary means.

Both bottom cover 1 and flange 35 have aligned apertures (see FIG. 18) to accomodate free linear movement of the drive bar 36 therethrough. When the drive bar 36 is moved toward the center of the switch, pawl 37 on the drive bar 36 is caused to move by a spring 38, and to engage a tooth 33 of rachet wheel 4, thus driving the rachet wheel through the desired angle. As this stroke of pawl 37 ends, a retaining pawl 39 (actuated by another spring not shown) swings about fixed pin to engage a convenient tooth to prevent the rachet wheel 4 from turning back when the drive bar 36 returns outwardly from its displaced position (i.e., moves away from the switch center).