JPH0345501B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a relatively small current-limiting fuse blowout display device used for PT, etc.

Prior Art In general, a fuse display device has a display piece 31 inside an insulating display tube 30 inserted into an insulating tube (not shown) as shown in FIGS. 5 and 6, and when the fuse is fused, The display piece 31 is made to spring out by a coil spring 32. In order to always place the display piece 31 in a recessed state inside the display tube 30 against the biasing force of the coil spring 32, the display resistance wire 33, which is conventionally inserted through the insulating tube 30 in the longitudinal direction, is inserted into the display tube 30. After being wound around one of the pair of hooks 34 and 35 provided at the inner end of the tube 30, it extends into the display tube 30 and resists the biasing force of the coil spring 32 to close the display tube. It is inserted into the display piece 31 held in the display tube 30, then reversed and wound around the other hook part 35 at the inner end of the display tube 30, and connected to an electrode (not shown) arranged at the outer end of the display tube 30. Ta.

Therefore, there is a problem in that the structure is complicated and time consuming to assemble the display piece 31 to the display tube 30.

OBJECTS OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a fuse blowout indicating device that has a simple structure and is therefore easy to assemble.

Structure of the Invention The fuse blowing display device of the present invention has a pair of electrodes arranged at both ends of an insulating tube, an element is connected between the two electrodes, a display tube is installed inside one electrode side, and the display tube has an element. In a fuse blowout display device that houses a display member that can protrude from the display tube insertion hole formed in the one electrode when the fuse blows out, the fuse is made of a conductive material and is electrically connected to the one electrode and is attached to the fuse. An indicator tube in which a protrusion is formed by caulking on the inner end side where the part is formed, an insulating cover fitted to the inner end of the indicator tube, and a locking piece accommodated in the indicator tube. The locking piece has a display member in which a locking protrusion facing the inner circumferential surface of the display tube is formed, and the protrusion is disposed within the display tube and has one end on the inner end side of the display tube. the other end is locked to the locking protrusion of the locking piece, and one end is connected to a spring that normally biases the display member in the protruding direction, and the other electrode; an element whose other end passes through the insulating lid, is locked to a locking piece of the display member inside the display cylinder, and then is reversed and locked to a locking part on the inner end side of the display cylinder;
It is equipped with the following.

Embodiments Hereinafter, embodiments of the present invention for displaying the blowout of vacuum fuses will be described with reference to FIGS. 1 to 4.

1 is an insulating tube, 2 is a cap-shaped electrode that is fitted and fixed to one end of the insulating tube 1, and 3 is a resistance wire as an element whose one end is connected to the electrode 2, which is inserted into the insulating tube 1. It is formed into a spiral shape. Reference numeral 4 denotes a cap-shaped electrode that is fitted onto the other end of the insulating tube 1 and fixed with adhesive, and a display tube insertion hole 5 is provided in the center thereof. A conductive metal display tube 6 whose inner end is housed in the insulating tube 1 is inserted into the insertion hole 5.
The outer circumferential surface of the insertion hole 5 is electrically connected by soldering or the like while being locked at the locking flange portion 7 at the outer end of the display tube.

Reference numeral 8 denotes a coil spring housed in the display tube 6, and its inner end includes a protrusion 9 formed on the inner periphery of the inner end of the display tube 6, and a protrusion formed by caulking from the protrusion 9 toward the outer end. It is fixed immovably between the parts 10 and 10. Reference numeral 11 denotes a display piece as a display member housed inside the display tube 6, and includes a locking piece 13 formed integrally with the disc-shaped display plate 12 and bent inward into an L-shape. It is configured.
The locking piece 13 has a width that is the same as the inner diameter of the coil spring 8, and has locking protrusions on both sides of its proximal end to which the outer end of the coil spring 8 is locked, as shown in FIG. 14 is formed in the radial direction of the display cylinder 6.

Then, by inserting the locking piece 13 into the outer end of the coil spring 8 while rotating the display piece 11, the locking protrusion 14 is engaged between the pitches of the coil spring 8 (see FIG. 3), and the coil spring 8 is rotated. It is attached so as to prevent it from coming off from the spring 8.

Reference numeral 15 denotes an insulating cover fitted to the inner end of the display cylinder 6, which has a through hole 16 in its center and a recess 17 cut into its outer periphery. Reference numeral 18 is a cylindrical copper caulking member through which the other end of the resistance wire 3 and one end of the display wire 19 constituting the element are inserted and caulked together. It is locked on the inner end surface. The display line 19 indicates the insulating lid 15.
It extends through the through hole 16 of the display tube 6, and is inserted through the locking piece 13 so that the display piece 11 is sunk into the display tube 6 while resisting the biasing force of the coil spring 8. . After insertion, the other end of the display line 19 is reversed and inserted into the recess 17 of the insulating cover 15.
It extends outside the display tube 6 through the inner periphery of the display tube 6 and is wound around a notch 20 as a shaping section cut into the inner end of the display tube 6 .

After the indicator line 19 is wound, the notch 20 is caulked in the direction of the arrow in FIG. A sealant 21 such as the like is filled to seal the inner end of the display cylinder 6 in a watertight manner.

Therefore, this fuse is electrically connected in the order of electrode 2→resistance wire 3→display line 19→display tube 6→electrode 4. Note that 22 is arc-extinguishing sand filled in the insulating cylinder 1. That is, this fuse itself has a current limiting effect.

Now, the fuse configured as described above is connected in parallel to a vacuum fuse (not shown) that is not equipped with a blowout indicator.

Then, when an overcurrent flows through the vacuum fuse and the vacuum fuse is cut off, a current flows through a fuse connected in parallel with the vacuum fuse, and the internal resistance wire 3 and indicator wire 19 are blown out. The display line 1
When fuse 9 is fused, the stored coil spring 8 is released and the display piece 11 is projected to the outside to indicate the fuse cutoff operation.

At this time, since one end of the coil spring 8 is engaged between the protrusion 9 and the protrusion 10 of the display tube 6, it does not come off from the display tube 6. Further, since the locking protrusion 14 of the display piece 11 is engaged between the pitches at the other end of the coil spring 8, the display piece 11 does not come off from the coil spring 8.

Further, unlike the conventional case, the display piece 11 and the coil spring 8 can be easily engaged with each other through the locking protrusion 14, and the spring 8 is protruded from the outer peripheral surface of the inner end side of the display tube 6 into which the spring 8 is inserted. By simply caulking the portion 10, the display tube 6, coil spring 8, and display piece 11 can be integrally assembled inseparably. Moreover, since the display tube 6 is made of a conductive material and is electrically connected to the electrode 4, after the display wire 19 inserted into the display tube 6 through the insulating cover 15 is inserted through the locking piece 13, The entire device can be easily assembled by simply reversing the display line 19 and winding it around the notch 20.

Effects of the Invention As detailed above, according to the present invention, the coil spring and the display member can be integrally assembled to the display tube with a simple structure and cannot be separated, and are engaged with the locking piece of the display member within the display tube. The effect is that the entire device can be easily assembled by simply engaging the other end of the element, which has been inverted after mating, to the engaging portion on the inner end side of the display cylinder. Therefore, it is an industrially excellent invention that is particularly effective when used for relatively small devices such as PT fuses or vacuum fuses to indicate melting.

[Brief explanation of drawings]

Fig. 1 is a half-sectional view of a fuse according to an embodiment of the present invention, Fig. 2 is a sectional view of the display tube, Fig. 3 is a sectional view of the main part showing how the display member is attached, and Fig. 4 is an insulating cover. and a perspective view of the inner end of the display tube, FIG. 5 is a sectional view of a conventional display tube, and FIG. 6 is a perspective view of the display tube. DESCRIPTION OF SYMBOLS 1... Insulating tube, 2, 4... Electrode, 3... Resistance wire as an element, 6... Display tube, 8... Coil spring, 10... Protrusion, 11... Display piece as a display member. , 13... Locking piece, 14... Locking protrusion, 15... Insulating lid, 19... Display line as an element.

Claims (1)

[Claims] 1. A pair of electrodes are arranged at both ends of an insulating tube, an element is connected between the two electrodes, and a display tube is installed inside one electrode side, and when the element is fused, the display tube has a In a fuse blowout display device that accommodates a display member that can protrude from a display tube insertion hole formed in an electrode, the fuse is made of a conductive material and is electrically connected to one electrode 4, and an engaging part 20 is formed. An indicator tube 6 having a protrusion 10 formed by caulking on the inner end side thereof, an insulating cover 15 fitted to the inner end of the indicator tube 6, and a lock housed in the indicator tube 6. The display member 11 has a piece 13, and the locking piece 13 is formed with a locking protrusion 14 facing the inner circumferential surface of the display tube 6; Tube 6
It is locked to the protrusion 10 on the inner end side, and the other end is locked to the locking protrusion 14 of the locking piece 13,
A spring 8 that normally biases the display member 11 in the projecting direction has one end connected to the other electrode 2, and the other end passes through the insulating lid 15, and the display member 11 is connected to the display member 11 in the display tube 6. After being locked with the locking piece 13 of
1. A fuse blowout display device comprising: elements 3, 19 that are attached to a fuse. 2. The fuse blowout display device according to claim 1, wherein the engaging portion is a notch 20 formed in the shape of a hook on the inner end of the display cylinder 6. 3. A recess 17 is provided on the outer periphery of the insulating lid 15 in correspondence with the notch 20, and the other ends of the elements 3, 19 are wound around the notch 20 of the display tube 6 through the recess 17. A fuse blowout indicating device according to claim 2.