Description

Limit Switch 

* Economical plastic housing, light weight
* Prevent oil and water
* Double way switch, double spring internal switch
* Variety of levers
* Widely used in mechanical equipment, automatic machine, tool, electric motion tool etc.

So what are the limit switches and what are they used for?

They may be called trip end switches, or electromechanical limit switches.

This switch performs a function like a manual push button switch, but the only difference is that the pressure is done mechanically instead of manually.

There are many types of mechanical means to operate these switches, including cams, levers, pulleys and cylindrical pistons, and the symbols used do not specify the type of actuator used.

It contains a number of open and closed contact points, and the position of these points changes when something collides with them. It can be seen frequently in cranes, elevators, and on transmission belts.

Using the mechanical end-of-stroke wrench on conveyor belts

Product technical specifications:

• Limit Switch 

• Type: Chinese
• Industrial use/application
• Switch type Rotary limit switch, lever limit switch
• The current rating is 10 amps
• The degree of protection is IP65
• Oil-proof, waterproof and dust-proof, rated structure
• The maximum AC voltage is 500V
• Operating ambient temperature (-10) – (+80)
• The mechanical operating cycle is 15,000,000 cycles
• Minimum operating temperature -10°C
• Maximum operating temperature +80°C
• Long life

1. Actuator

It is considered part of the key, and through it the sensation is transmitted to the rest of the parts of the key. There are many forms of it, and there are three types:

• Side Rotary.
• Side or Top Push.
• Wobble Stick or Cat Whisker.

The Actuator has two modes:

• The non-operating Reset Point position, which is not affected by any force or torque.
• Trip Point operating mode When the actuator is affected by force or torque, it moves from Reset mode to Trip mode.

Solid Rotary type

It is a prominent column installed next to the head of the Limit Switch, and when it moves, the connection points work, and this type can move in one direction or two directions (Uni-direction_Bi-direction).

An arm called the Lever Arm is attached to the column, and there are many forms of this arm, as shown in the figure.

Top push side type

It is a short button installed on the head of the key. When pressed, the key works.

It is often with a spring so that it can return to its normal position when the pressure is removed, and there are few types that do not have this spring. In this case, this button is pressed in the opposite direction until it returns to its normal position and there are many shapes as shown in the form.

Wobble Stick or Cat Whisker

It is a long and thin arm fixed to the head of the limit switch, and when it is moved in any direction, the switch works. This arm is made of a flexible wire wrapped in a certain way, so that it gives great flexibility and ease of moving it in any direction, and it returns to its normal position when the force is removed.

The shape of the movement arm, the extent to which it will withstand shocks, and its mechanical design must be determined so as to suit the nature of the mechanical part that it will collide with.

2. Head

The head is the part in which the mechanical parts responsible for transferring movement from the actuator actuator to the contact points are located. When the actuator moves, the mechanical part presses on the connection points and changes their state (close or open).

3. Contact Block

It contains a set of connection points that can be two pairs of connection points or four pairs, and their normal position is Normal Close or Normal Open. The number of contact points that we will need must be determined.

4. Terminal Block

It contains screws through which the electrical wires are connected to the connection points.

5. Switch Body

It contains a box of points and terminals.

Operating environment, i.e. the place where the key will be installed, in terms of moisture, dust, temperature and vibration so that we can determine the appropriate shape and external structure of the key.

Is it made of metal or plastic?

In the chemical and fertilizer industries, a plastic structure is preferred if the temperature is not high.

It must determine how to install it and put it in its proper place