JPS6013146Y2 - thermostat - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of thermostats used in electric heating appliances such as electric irons.The purpose of this invention is to reduce the occurrence of arcs when the contacts open and close by adopting a snap action mechanism. It is something to do.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a base made of an insulating material such as porcelain, on which terminal plates 2 and 3 are attached with screws 2' and 3'.

Reference numeral 4 denotes an intermediate fixed base to which the base of a fixed contact plate 7 having a fixed contact 5 on the base side and an operating rod holder 6 on the tip, and one side of a support spring 8 and a support plate 9 are attached with screws 10. The support spring 8 and the support plate 9 are insulated from each other.

The support plate 9 has one side connected to the terminal 3 of the base 1, has spring properties, and is biased upward.

11 is a lead plate installed between the fixed contact plate 7 and the terminal 2 of the base 1.

The support spring 8 has a rectangular shape and has a punched part in the center, and one end is fixed to one end of a snap spring 13 having a movable contact 12 corresponding to the fixed contact 5, and the snap spring 13 has a punched part in the center. It has a toggle spring 14.

The support spring 8 also has a spring receiving tongue 15 at the end of the punched portion.

One end of the toggle spring 14 is movably attached to the spring receiving tongue piece 15, and the two are pushed against each other.

Reference numeral 16 denotes an actuating rod whose one end is fitted into the actuating rod receiver 6, and is structured so that the fixed contact plate 7 can be moved up and down by moving the actuating rod 16 up and down.

Reference numeral 17 is a bimetal whose one end is attached to a heating plate 18 having a heater, and a U-shaped support fitting 19 is attached to the other end of this bimetal 17, and an adjustment corresponding to the top surface of the end of the snap spring 13 is attached to this support fitting 19. A screw 20 is attached, and an insulator 21 is provided at the tip of the adjustment screw 20.

Further, the bimetal 17 is configured to be bent downward by the heat of the heater, and causes the snap spring 13 to move up and down.

The operation of the above configuration will be described.

First, the distance between the insulator 21 and the snap spring 13 is adjusted by pushing down the actuating rod 16 from a state where the insulator 21 is in contact with the upper surface of the end of the snap spring 13, and the set temperature is low. do.

When the heater is energized in this state, that is, with a certain gap maintained between the insulator 21 and the snap spring 13,
The bimetal 17 is bent downward by the heat of the heater, and when the insulator 21 comes into contact with the snap spring 13, the toggle spring 14 tries to repel this, but the snap spring 13
When it exceeds the dead end, the snap spring 13 rapidly reverses.

As a result, the movable contact 12 attached to the snap spring 13 is separated and opened more quickly than the fixed contact 5.

After that, when the bimetal 17 cools down, it returns upward, and in the process of returning to its original position, when the snap spring 13 crosses the dead center, it reverses itself, and the movable contact 12 contacts the fixed contact 5, closing the circuit again.

This is repeated by the movement of the bimetal 17.

As described above, according to the present invention, since the snap action mechanism is fixed to the intermediate fixing base, the snap action is reliably performed, and the generation of arcs when opening and closing the contacts can be kept to a minimum.

In addition, even when the temperature is variable, the base is fixed, so the support plate and lead plate that connect the intermediate fixed base and the base become cantilevered by the upper and lower movement of the operating rod, and the dimensions of the snap action mechanism are always constant. Therefore, the snap action maintains stable operation regardless of whether the set temperature is high or low.

Furthermore, the snap spring is rectangular, and a punched torque spring is movably attached to the center of the spring, so the snap spring does not twist when the bimetal is activated, and the contact always operates normally, allowing accurate temperature control. It has excellent effects such as being able to perform.

[Brief explanation of the drawing]

FIG. 1 is a front view of a thermostat showing an embodiment of the present invention, FIG. 2 is a plan view of the main part of FIG. 1, and FIG. 3 is a bottom perspective view of the thermostat. 1...Base, 4...Intermediate fixing base, 5.
...Fixed contact, 7...Fixed contact plate,
...Support spring, 9...Support plate, 12...
...Movable contact plate, 13...Snap spring, 1
4... Toggle spring, 15... Spring receiving tongue piece, 17... Bimetal.

Claims (1)

[Scope of utility model registration request] The terminal plates 2 and 3 are attached to the upper surface of the base 1 made of an insulating material, and the base of the fixed contact plate 7 has a fixed contact 5 on the base side and an operating rod holder 6 on the tip, and a rectangular shape with a punched shape in the center. One side of the support spring 8 and the support plate 9 are fixed to the intermediate fixed base 4 with insulation between the fixed contact plate 7 and the support spring 8, and one side of the support plate 9 and the fixed contact plate 7 is fixed to the intermediate fixed base 4. The support spring 8 is connected to the terminal plates 3 and 2 of the base 1, and one side of the support spring 8 is fixed to one end of a snap spring 13 having a movable contact 12 corresponding to the fixed contact 5. A spring receiving tongue piece 15 is formed at the end of the spring, and a snap spring 13
A punched torque spring 14 is formed in the center of the spring, one end of the torque spring 14 is attached movably and against the spring receiving tongue 15, and one end is heated to one end of the snap spring 13. The thermostat is constructed by making the other end of a bimetal 17 attached to a plate 18 correspond to each other via an adjustment screw 20 and an insulator 21, and opening and closing a fixed contact 5 and a movable contact 12 by the movement of the bimetal 17.