JPS6318101Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a flameproof explosion-proof switch, and particularly relates to an improved structure of a contact block.

In general, flameproof explosion-proof switches, by their nature, keep the internal space of the switching chamber below a certain volume, reducing the explosive force even if an explosion occurs inside the switching chamber due to the arc generated by opening and closing the contacts. At the same time, consideration must be given to prevent ignition from spreading to the outside.

For this purpose, a configuration as shown in FIG.
Parallel recessed holes 1a for inserting two sets of normally open and normally closed fixed contacts 2, 2 and 3, 3 from the top surface toward the inside;
1a, and a recessed hole 1b for inserting a support body 6 made of an insulating material which bridges both the recessed holes 1a, 1a at the center and supports the support spring 4 and the movable contact 5, thereby forming an opening/closing chamber inside. It consists of

After the normally open fixed contacts 2, 2 are fitted and fixed into the respective recesses 1a, 1a, the support body 6 is inserted together with the support spring 4 into the fitting insertion recess 1b, and then the normally closed fixed contacts 3, 3 are inserted into the recessed holes 1b. are inserted and fixed into the respective recessed holes 1a, 1a, and the operation frame 7 is fixed with the mounting screws 8. At this time, while pressing the support body 6, the normally closed fixed contacts 3, 3 are inserted into the respective recessed holes 1a. , 1a, it is difficult to fix the normally closed fixed contacts 3, 3, and the sequential assembly method requires a large number of man-hours. Note that 9 is a push button supported by a spring 10.

This invention was proposed to improve these drawbacks, and will be explained below based on the embodiments shown in FIGS. 2 to 4. Components that are the same as those in FIG. 1 are indicated by the same symbols.

The main body 1 of this invention is made of a molded insulator,
A recess 11 is formed in the center of the upper surface of the main body 1, and a step 11a is formed on the side wall of the recess 11 from the middle to the bottom of the recess 11. A concave recess 11b for inserting the support spring 4 is formed in the recess 11b, and the normally open fixed contacts 2, 2 have their contact portions directed toward the stepped portion 11a at the inner bottom on both sides of the concave hole 11b. They are arranged in parallel and fixed. On the other hand, the normally closed fixed contacts 3, 3 are
The bases are arranged and fixed in parallel on the upper surface of the stepped portion 11a, and the contact portions are provided to face the contact portions of the normally open fixed contacts 2, 2.

12 is a block piece made of a substantially square-shaped molded insulator that can be fitted into the recess 11 of the main body 1, and has an insertion hole 12a for the support 6 in the center;
The lower part of 2a becomes a recess 12b that forms an opening/closing chamber when fitted to the main body 1.

Therefore, according to this invention, the support spring 4 is inserted into the recessed hole 11b at the inner bottom of the main body 1, and the movable contact 5 is pushed down while pressing down the support body 6 whose lower end is engaged with the support spring 4. It is interposed on the lower surface facing contact side of the normally closed fixed contact 3 to stabilize it.

Next, the support 6 is inserted into the through hole 12a of the block piece 12.
After fitting into the recess 11 while inserting the upper part of the main body 1 and the operating frame 7, the main body 1 and the operating frame 7 are fixed with the mounting screws 8. At this time, the upper end of the support 6 is exposed at the upper end of the opening of the through hole 12a of the block piece 12, and the push button 9 of the operation frame 7
The pressed lower ends of the two face each other. Note that 13 and 14 are external connection terminals connected to the normally open and normally closed fixed contacts 2 and 3.

As explained above, in this invention, a recess 11 is formed in the main body 1, and a stepped portion 11b is formed on the side wall of the recess 11 from the middle to the bottom of the recess 11.
The assembly is made simple by simply forming a block piece 12 which fills in a blank part while leaving an opening/closing chamber part, and the number of assembly steps can be reduced because division of labor during assembly becomes possible. Furthermore, the contacts can be easily cleaned and inventory can be managed effectively.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a conventional example, Figs. 2 to 4 show an embodiment of this invention, Fig. 2 is an exploded perspective view, Fig. 3 is a vertical sectional view, and Fig. 4 is only the main body. FIG. DESCRIPTION OF SYMBOLS 1... Main body, 2... Normally open fixed contact, 3... Normally closed fixed contact, 4... Support spring, 5... Movable contact, 6... Support body, 11... Recess, 11a... ...Ranked section, 12...Block piece.

Claims (1)

[Scope of utility model registration request] A recess is formed on the upper surface of the main body made of a molded insulator, and a step is formed on the side wall of the recess from the middle to the bottom of the recess, and the recess is permanently fixed at the inner bottom of the recess where there is no step. A contact is fixed, a normally closed fixed contact is fixed on the upper surface of the stepped portion facing the normally open fixed contact, and a movable contact is supported between the normally open fixed contact and the normally closed fixed contact. The movable contact support body is inserted by being supported by a spring, and a block piece is fitted into the recess leaving an opening/closing chamber, and the movable contact support body is fitted into and supported by the block piece. Flameproof explosion-proof switch.