BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an earth leakage breaker;
FIG. 2 is a disassembled side view of a main body housing of the breaker of FIG. 1;
FIG. 3 is a perspective view showing the internal structure of the breaker with the main body housing disassembled;
FIG. 4(
a) through FIG. 4(d) are supplementary illustrations showing arrangement of an earth leakage tripping device and an earth leakage operation output switch mounted on the earth leakage breaker, wherein FIG. 4(a) is a plan view of the whole breaker with a top cover, FIG. 4(b) is a plan view without a top cover, FIG. 4(c) is an enlarged plan view of a region “P” in FIG. 4(b), and FIG. 4(d) is an enlarged plan view of the region “P” in which the earth leakage trip device and the earth leakage operation output switch are removed from the configuration in FIG. 4(c) to empty the recess of the case cover;
FIG. 5 is a perspective view in which an earth leakage operation output switch is inserted and held in the earth leakage trip device in FIG. 1;
FIG. 6 is a side view of FIG. 5;
FIG. 7 is a disassembled perspective view of a trip coil unit in FIG. 5;
FIG. 8 is a perspective view of the earth leakage trip device of FIG. 5 before mounting an earth leakage operation output switch;
FIG. 9 is a front view of the earth leakage operation output switch;
FIG. 10(
a) and FIG. 10(b) are perspective views of FIG. 9, in which FIG. 10(a) is seen from the front side and FIG. 10(b) is seen from the rear side;
FIG. 11(
a) and FIG. 11(b) are perspective views illustrating the earth leakage operation output switch with the lead wires entangled with the support member and lead out sidewardly, in which FIG. 11(a) is seen from the front side, and FIG. 11(b) is seen from the rear side;
FIG. 12(
a) and FIG. 12(b) are perspective views illustrating the earth leakage operation output switch with the lead wires entangled with the support member and lead out forwardly, in which FIG. 12(a) is seen from the front side, and FIG. 12(b) is seen from the rear side;
FIG. 13 is a perspective view illustrating the lead wires of the earth leakage operation output switch inserted and set in the case cover of the earth leakage breaker in the arrangement of the wires lead out sidewardly corresponding to FIG. 11;
FIG. 14 is a perspective view illustrating the lead wires of the earth leakage operation output switch inserted and set in the case cover of the earth leakage breaker in the arrangement of the wires lead out upwardly corresponding to FIG. 12;
FIG. 15 is a perspective view illustrating a configuration with the top cover (auxiliary cover) covering the case cover of the main body housing of FIG. 13; and
FIG. 16(
a) and FIG. 16(b) illustrate a conventional earth leakage tripping device having an earth leakage operation output switch installed in an earth leakage breaker, in which FIG. 16(a) is a plan view of a partial cross section, FIG. 16(b) is a plan view of a structure of an essential parts of FIG. 16(a).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Some preferred embodiments according to the invention will be described with reference to FIGS. 1 through 15. FIG. 1 through FIG. 4(d) show a structure of an earth leakage breaker mounting an earth leakage operation output switch; FIG. 5 through FIG. 8 show a structure of an earth leakage trip device mounted on an earth leakage breaker; FIG. 9 to FIG. 10(b) show a structure of an earth leakage operation output switch; and FIG. 11(a) through FIG. 15 show lead out and wiring structure of lead wires connected to the earth leakage operation output switch.
Referring to FIG. 1 through FIG. 3, a main body housing 6 of an earth leakage breaker has a structure divided into a case 6a, a case cover 6b, and a top cover (auxiliary cover) 6c made of molded resin. The case cover 6b in the figures is divided into a cover division 6b-1 covering a supply side area of the main body housing 6 and a cover division 6b-2 covering a load side area (FIG. 2). The top cover 6c is attached for allowing opening and closing. One end of the top cover 6c is combined with the cover division 6b-2 by a hinged coupling, and the other end of the top cover 6c is combined with the upper surface of the cover division 6b-1 by a screw coupling.
Installed in the case 6a are a switching operation handle 7, a switching mechanism 15, an arc extinguishing chamber 16, a zero phase current transformer 17, and an earth leakage trip device 1 in the side of the handle 7 (FIG. 3). The case cover 6b covering the case 6a has a recess 6b-3 with a pocket configuration in the both sides of the operation handle 7 for accommodating various internal accessory devices including an earth leakage operation output switch 5 that is mounted on the earth leakage trip device 1 afterwards, an auxiliary switch, an alarm switch and the like. The case 6a and the accessories are covered by the top cover 6c. In FIG. 1, the reference numeral 12 designates an earth leakage test button, and the numeral 13 designates knobs of switches for sensitivity current and operation time selection. These parts are installed in a unit case of the earth leakage trip device 1 as described below.
FIGS. 4(
a) through 4(d) are supplementary illustrations of the earth leakage breaker with an earth leakage operation output switch 5 mounted afterwards in the main body housing 1, in which FIG. 4(a) shows a state with a top cover 6c shown in FIG. 1, FIG. 4(b) shows a state that the cover is removed, FIG. 4(c) is an enlarged plan view of the region “P” in a state the cover division 6b-2 is removed, and FIG. 4(d) is a drawing for reference showing a state in which the earth leakage trip device 1 and the earth leakage operation output switch 5 have been removed from the main body housing to empty the recess 6b-3 of the case cover 6b. In FIGS. 4(c) and 4(d), the reference numeral 14 designates an earth leakage detection circuit (a printed circuit board) contained in a printed board accommodation portion 11a of the unit case 11 described later, and the numeral 15 designates a switching mechanism for a main circuit contact. A U-shaped groove 6b-4 is formed at the upper edge of a side wall of the case cover 6b for leading out lead wires 18 connected to the earth leakage operation output switch 5 outwardly.
Descriptions will be made on an assembly structure of the earth leakage trip device 1 referring to FIGS. 5 through 8; and on the structure of the earth leakage operation output switch 5 referring to FIGS. 9, 10(a) and 10(b).
The earth leakage trip device 1 shown in FIG. 5 and FIG. 6 comprises a unit case 11; components contained in the unit case 11 as a unit including an earth leakage detection circuit 14 (FIG. 4(c)), an earth leakage test switch 12, switches 13 for sensitivity current and operation time selection, and an assembly of a trip coil unit 8 shown in FIG. 7; and a switch housing 11b for accommodating and holding an earth leakage operation output switch 5 provided on a side surface of the unit case 11.
The trip coil unit 8 is, as shown in FIG. 7, an assembly comprising a case 10; and an earth leakage indication button 4 and a trip actuation slider 9 coupled with a trip coil 3 (a plunger type electromagnet) through a driver lever 3b inserted into the case 10. This case 10 is fitted to the unit case 11 of the earth leakage trip device 1 by snap fitting (FIG. 5). In this fitted state, the dog 9a for switching operation branched from the side of the actuation slider 9 is projecting to the bottom of the switch housing 11b formed on the unit case 11.
The earth leakage operation output switch 5 is a micro-switch including a contact mechanism (c-contact) provided with normally-open and a normally-close contact points. As shown in FIG. 9 and FIGS. 10(a) and 10(b), a plunger 5b, an actuator of the contact mechanism, is projecting from the bottom surface of a switch case (a molded resin case). On the left and right end surfaces, engage projections 5d and a hook 5e (snap fit) are formed in a monolithic construction. On the top of the micro switch, lead wire supports 5c (three pieces) are provided in a form of a bar with a rectangular cross section directing right-wards or left-wards and having an L-shaped bent at the tip. The lead wire supports are retaining members to entangle three lead wires 18 (FIG. 8) that are connected to the internal contacts and lead out to the top surface of the switch case.
The unit case 11 (a molded resin case) of the earth leakage trip device 1 in FIG. 8 includes a housing 11a for a printed circuit board 14 for the earth leakage detection circuit (FIG. 4(c)) and the switch housing 11b in a pocket shape for removably accommodating and holding the earth leakage operation output switch 5. The housing 11a and the switch housing 11b are formed in a monolithic construction in the unit case 11. The switch housing 11b has a fitting groove 11b-1 and snap fit part 11b-2 corresponding to the engage projections 5d and hook 5e, respectively, of the earth leakage operation output switch 5. The numeral 11c designates a snap fit member for engaging and holding the case 10 (FIG. 7) of the trip coil unit 8.
In the assembled state having the earth leakage trip device 1 mounted on the main body housing 6 (FIG. 1), the switch housing 11b formed on the side surface of the unit case 11 (FIG. 8) faces the recess 6b-3 formed in the case cover 6b, and projecting from the top surface of the case cover 6b are the earth leakage indicating button 4, a push button 12 of the earth leakage test switch, and the knobs 13 of the switches for rated sensitivity current and operation time selection.
When an earth leakage operation output switch 5 is installed afterwards into the earth leakage breaker in the structure as described above, after opening the top cover 6c as shown in FIG. 1, the earth leakage operation output switch 5 is inserted from above towards the recess 6b-3 of the case cover 6b opening outside the earth leakage trip device 1 and pushed down into the switch housing 11b of the unit case 11 as shown in FIG. 8, and removably engaged and fixed at a predetermined position. In this held state of the switch, the tip of the dog 9a (which is cut tapered) branched from the actuation slider 9 of the trip coil unit 8 (FIG. 7) is located opposing the side of the plunger (actuator) 5b of the earth leakage operation output switch (micro switch) 5 as shown in FIG. 6.
In the above described structure, on the event of ground fault in the distribution system, the earth leakage detection circuit 14 detects earth leakage current in the main circuit. The output signal from the earth leakage detection circuit 14 operates the trip coil 3 of the earth leakage tripping device 1 driving the actuation slider 9 to trip the switching mechanism 15 and open the main circuit contacts. At the same time, the dog 9a branched from the actuation slider 9 moves to the direction of the arrow in FIG. 6 and pushes the plunger (actuator) 5b of the earth leakage operation output switch 5 inwardly. The contact (a “make” contact) of the micro switch turns ON, and an electric signal indicating earth leakage operation is output through the lead wires 18. When electric indication of earth leakage operation is not needed in the system, the earth leakage operation output switch 5 can be removed from the case cover 6b of the main body housing 6, and the breaker can be used as a normal (standard specification) earth leakage breaker. In such a case, the earth leakage operation can be seen by pop-up action of the earth leakage indication button 4.
Next, a description will be made on a process, in the state of the earth leakage operation output switch 5 post-mounted on the earth leakage breaker, to arrange the lead wires 18 connected to the switch towards the side or above from the main body housing 6 of the breaker and lead out of the breaker referring to FIG. 11(a) through FIG. 15.
After the earth leakage operation output switch 5 is inserted and set on the main body housing 5 of the earth leakage breaker, in the case that the lead wires 18 connected to the earth leakage operation output switch 5 are lead out to the side of the main body housing 6 as shown in FIG. 15 (the arrow “A” designates the lead out direction of the lead wires) and externally wired, the three lead wires 18 lead out above the switch are entangled with the lead wire support 5c and lined up tightly as shown in FIGS. 11(a) and 11(b). The lead wires are lead out through a groove 6b-4 (FIG. 4(d)) formed on the side edge of the cover 6b as shown in FIG. 13. When the top cover 6c of the main body housing 6 is closed in this state, the lead wires 18 are pressed between the side edge of the case cover 6b and the edge of the top cover 6c in the intermediate portion of the lead wires and fixedly held at this position. If an external tensional force is exerted on the lead out lead wires 18, there is no risk that the lead wires come off accidentally from the micro switch or the switch itself slips off from the unit case 11 of the earth leakage trip device 1.
When the lead wires 18 cannot be lead out for wiring sideways as shown in FIG. 15 due to restriction by the surroundings of the installed earth leakage breaker, and the lead wires 18 are to be lead out for wiring towards upward along the surface of the main body housing 6 as in FIG. 14, the three lead wires 18 are entangled with the lead wire support 5c and lined up tightly to draw out in the direction of the arrow “A” as shown in FIGS. 12(a) and 12(b). Then, the top cover 6c is put and bound in the same process as the above-described one. Thus, the lead wires 18 drawn out in the direction of the arrow “A” are pressed between the edge of the case cover 6b and the edge of the top cover 6c in the intermediate portion of the lead wires and fixedly held at this position.
The lead wire supports 5c in a form of a bar with a rectangular cross section are provided on the top of the micro switch, and when the lead wires 18 are lead out for wiring from the earth leakage operation output switch 5 post-mounted on the main body housing 6 of the earth leakage breaker, the lead wires 18 can be lead out in a desired direction and held on the main body housing 6 by wiring in the above described process.
The disclosure of Japanese Patent Applications No. 2006-282096 filed on Oct. 17, 2006 and No. 2006-105830 filed on Apr. 7, 2006 are incorporated as a reference.
While the invention has been explained with reference to the specific embodiments of the invention, the explanation is illustrative and the invention is limited only by the appended claims.
Patent Application
20070236841
