JPH0536736U - Circuit breaker - Google Patents

Abstract

(57) [Summary] [Structure] When fixing the circuit breaker to the mounting plate 13, the through holes 23a formed in the cover 23 and the case body 22,
22b through mounting screw 14. Through hole 22
b has a large diameter part in which the head of the mounting screw 14 can be housed and a projection 22c for preventing the mounting screw 14 from falling out, and the head of the mounting screw 14 is located in the large diameter part. Thus, the mounting screw 14 is housed in the through hole 22b in advance. Further, a coil spring 17 that constantly presses in the direction of the protrusion 22c may be provided on the outer periphery of the mounting screw 14. [Effect] Since the mounting screw 14 is previously mounted in the through hole 22b of the case 21, it is necessary to insert the mounting screw 14 into the through hole 22b of the case 21 each time the circuit breaker is fixed to the mounting plate 13. There is no. Moreover, mounting screw 1
There is no drop or loss of 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a circuit breaker.

[0002]

[Prior Art]

 The circuit breaker generally has a structure as shown in FIG. That is, the case 1 made of an insulating material is provided with a case main body 2 for accommodating the blocking element therein and a cover 3 for closing the upper opening of the case main body 2. In this case, the base member 4 may be detachably attached to a part of the bottom surface of the case body 2. The breaking element is a fixed contact 6 having a fixed contact 5 fixed to the case body 2, a movable contact 8 having a movable contact 7 facing the fixed contact 5 of the fixed contact 6 on one end side, and the movable contact. The separation spring 9 for urging the movable contact 8 from the fixed contact 6 and the movable contact 8 located between the separation spring 9 and the movable contact 7 of the movable contact 8 are engaged with the movable contact 8. A cross bar 10 which is slidably provided along the sliding wall 2a of the case body 2 and the movable contact 8 is brought into contact with and separated from the fixed contact 6 by sliding the cross bar 10. An operating mechanism 11 for operating the operating mechanism 11 and a trip device 12 for operating the operating mechanism 11 so that the movable contact 8 is separated from the fixed contact 6 when an overcurrent is detected.

Such a circuit breaker is generally fixed by mounting the case 1 on the mounting plate 13. In this case, in the case 1, the cover 3 and the case body 2 are formed with through holes 3a and 2b, respectively, and the base member 4 is formed with a through hole 4a having a smaller diameter than the through holes 3a and 2b. The mounting screw 14 is inserted through the through holes 3a, 2b and 4a, and the mounting screw 14 is screwed into the screw hole 13a provided in the mounting plate 13 to fix the case 1. The base member 3 is fixed to the case body 2 by separately screwing a fixing screw 15 into the case body 2 from the bottom surface side.

One such screw mounting portion is provided between the terminal portions on the load side and the power source side, which are diagonally positioned on the case 1, and the case 1 is mounted on the mounting plate 13 via the screw mounting portion. Fixed to.

[0005]

[Problems to be solved by the device]

 In the fixing structure as described above, the mounting screw 14 may fall out when the mounting screw 14 is inserted into the through holes 3a, 2b of the case 1 or after the insertion, and may be lost. There was a problem. The present invention has been made to solve the above problems, and an object of the present invention is to provide a circuit breaker capable of preventing a mounting screw from falling off.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, a case including a case body for accommodating a blocking element therein and a cover for closing an upper opening of the case body is formed in the cover and the case body. In the case of a circuit breaker that is fixed to a mounting plate with a mounting screw through a through hole, at least a part of the through hole is made large enough to accommodate the head of the mounting screw, and the head of the mounting screw is placed in this through hole. While being housed, it is characterized in that a projecting portion is formed in the through hole to prevent the mounting screw from falling off. The feature is that a coil spring that constantly presses toward the protruding portion is provided on the outer circumference of the mounting screw.

[0007]

[Action]

 Since the mounting screw is installed in the through hole of the case in advance, it is not necessary to insert the mounting screw into the through hole of the case each time the circuit breaker is fixed to the mounting plate. Moreover, the mounting screws do not drop or get lost. In addition, by inserting a tool through the through hole of the case and screwing in the mounting screw, the case can be easily fixed to the mounting plate, and workability is good. Further, since the mounting screw is constantly pressed against the protruding portion by the coil spring, rattling does not occur.

[0008]

Embodiment An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, the case 21 has a case body 22 and a cover 23 each made of an insulating material, and further has a base member 24 for closing a part of the bottom surface of the case body 22. A breaking element is housed inside the case body 22, and this breaking element has a fixed contact 6 having a fixed contact 5 fixed to the case body 22, and a movable contact 7 facing the fixed contact 5 at one end side. The movable contactor 8 is provided. A separation spring 9 composed of a compression coil spring is provided on the other end side of the movable contactor 8, and always urges the movable contactor 8 upward in the contact separation direction with the crossbar 10 as a fulcrum. The crossbar 10 is located between the opening spring 9 and the movable contact 7 of the movable contact 8, is in contact with the movable contact 8, and is slidable along the sliding wall 22a of the case body 22. There is. The operation mechanism 11 has a handle, a link mechanism, and the like, and slides the crossbar 10 along the sliding wall 22a to bring the movable contact 8 into contact with and separate from the fixed contact 6. The trip device 12 operates the operating mechanism 11 so that the movable contact 8 is separated from the fixed contact 6 when overcurrent is detected.

The case 21 accommodating such a shut-off element is provided with a screw mounting portion at one position between the phases of the power source side and load side terminal portions which are diagonally located when viewed from the upper surface. It is fixed to a mounting plate 13 such as a distribution board via the section. Although only the screw mounting portion on the power supply side is shown in the figure, this screw mounting portion is attached using the through holes 23a, 22b, 24a formed in the cover 23, the case body 22 and the base member 24, respectively. Is to be screwed into the screw hole 13a of the mounting plate 13. In this case, the base member 24 is fixed to the case main body 22 from the bottom surface side by the fixing screw 15, and the washer of the mounting screw 14 abuts on the peripheral portion of the upper surface of the through hole 24a of the base member 24, so that the case 21 is fixed to the mounting plate 13 via the base member 24. Here, the through hole 22b of the case main body 22 is formed as a stepped hole having a large diameter portion on the base member 24 side and a small diameter portion on the cover 23 side, and the diameter D of the large diameter portion is determined by the mounting. The diameter of the small diameter part is smaller than the head diameter of the mounting screw 14 and is smaller than the head diameter of the mounting screw 14 so that the head part of the mounting screw 14 can be housed. The size is such that it can be inserted and rotated. As a result, a protrusion 22c is formed on the inner surface of the through hole 22b of the case body 22 to prevent the attachment screw 14 from falling off. Further, the axial length of the large diameter portion of the through hole 22b is formed shorter than the axial length of the mounting screw 14 so that the mounting screw 14 does not come out of the through hole 24 of the base member 24. Therefore, even when the mounting screw 14 is inserted into the large-diameter portion of the through hole 22b and the through hole 24 of the base member 24 in advance at the time of assembling the circuit breaker and assembled, the head portion of the mounting screw 14 has the through hole 22b. Since it hits the protruding portion 22c of the cover 23, it does not fall out through the through hole 23a of the cover 23. Therefore, if the mounting screws 14 are previously assembled in the case 12 as described above, it is necessary to separately insert the mounting screws into the through holes 23a and 22b of the case 21 when fixing the circuit breaker to the mounting plate 13. The case 21 can be easily fixed to the mounting plate 13 by positioning it in the screw hole 13a of the mounting plate 13 as it is, inserting a tool such as a screwdriver into the through holes 23a and 22b, and screwing the mounting screw 14. become able to.

2 to 4 show other embodiments of the present invention. FIG. 2 shows the case 31 formed by the cover 23 and the case body 32 without using a base member. In this case, the through hole 32b of the case main body 32 is formed to have a size slightly larger than the head diameter of the mounting screw 14 over the entire axial direction, and after the mounting screw 14 is inserted through the through hole 32b, it is larger than the tool diameter. By inserting the ring 16 having a hole smaller than the head diameter and configuring the lower end of the ring 16 as the protrusion 32c, the same effect as that of the first embodiment can be obtained.

3 and 4, the coil spring 17 is provided outside the mounting screw 14 to prevent the mounting screw 14 from rattling by constantly pressing the mounting screw 14 against the protrusion 22c. Is. 3 shows a cylindrical projection 22d formed on the peripheral edge of the upper surface of the through hole 24a of the base member 24, and the coil spring 17 arranged outside the projection 22d, and FIG. The through hole 24a is formed in a stepped manner, and the coil spring 17 is arranged in the large diameter portion thereof, and the buckling of the coil spring 17 is prevented by the outer peripheral surface of the protrusion 22d or the inner peripheral surface of the through hole 24a. is doing.

By thus preliminarily incorporating the mounting screw into the screw mounting portion of the case of the circuit breaker, the mounting screw is inserted into the case of the circuit breaker when fixing the circuit breaker to the mounting plate. There is no need to do it, and you can fix it by simply positioning it in the screw hole of the mounting plate and screwing in the mounting screw, which simplifies the work. Also, by always pressing the mounting screw against the protruding part of the through hole, rattling of the mounting screw can be prevented, and if the tool is inserted into the through hole, it easily engages with the head of the mounting screw. It becomes easier to engage the mounting screw with the mounting screw, and the work becomes even easier.

[0013]

[Effect of the device]

 As described above, according to the present invention, the mounting screw is attached in advance to the screw mounting portion of the case of the circuit breaker so that it cannot be removed. It is not necessary to insert it into the through hole, and it can be fixed simply by positioning it in the screw hole of the mounting plate and screwing it in, which makes the work extremely easy.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a circuit breaker according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing a main part of another embodiment of the present invention.

FIG. 3 is a side sectional view showing a main part of another embodiment of the present invention.

FIG. 4 is a side sectional view showing a main part of another embodiment of the present invention.

FIG. 5 is a side sectional view of a conventional circuit breaker.

[Explanation of symbols]

1, 21, 31 are cases, 2, 22, 32 are case bodies, 3, 23 are covers, 6 are fixed contacts, 8 are movable contacts, 9 is a spring for opening and closing, 10 is a crossbar, and 11 is an operation. A device, 12 is a trip device, 13 is a mounting plate, 14 is a mounting screw, and 22c and 32c are protrusions.

Claims (2)

[Scope of utility model registration request] 1. A case comprising a case main body for accommodating a blocking element therein and a cover for closing an upper opening of the case main body, and a mounting plate with a mounting screw through a through hole formed in the cover and the case main body. In the circuit breaker fixed to, the at least a part of the through hole is formed to have a size capable of accommodating the head portion of the mounting screw, and the head portion of the mounting screw is accommodated in the through hole while the through hole is disposed. A circuit breaker characterized in that a protruding portion for preventing the mounting screw from coming off is formed on the. 2. The circuit breaker according to claim 1, wherein a coil spring is provided on the outer periphery of the mounting screw so as to constantly push in the direction of the protruding portion.