# Simple mechanical closures for traps, responsive to mechanical vibrations and changes in the position of the sensing element, design and installation features.

There are simple mechanical closures that respond to mechanical vibrations and changes in the position of the sensor relative to the vertical axis, the position relative to the magnetic poles or the installed position in any plane.

In the first case, the closure is a load on the spring. A load can have (depending on various design considerations) a different configuration, but only the load mass and spring stiffness matter in principle.

## Simple mechanical closures for traps, responding to mechanical vibrations and changes in the position of the sensing element, design and installation features.

The frequency of natural oscillations is easily calculated, and in the case of resonance, the load overcomes the contact space. Such contactors are often installed in transport, under the railroad bed, etc. When vibrations of a certain frequency (engine operation at certain revolutions) occur, contact closure occurs. It is necessary that the ratio of the spring stiffness to the mass of the load is equal to the product of the square of the frequency you need by four “pi” squared.

In public places, suitcases often place a metal tube with a rod suspended inside; in case of tilting or swinging the suitcase, the rod touches the tube walls and closes the chain. This design is not bad for mining cars, the explosion will occur with a certain acceleration. Say when starting off. A similar design can be performed as a resonating device (a variant of the previous design), but the rod suspended inside the tube will play the role of the pendulum. If the tube is also suspended, it is better that the natural frequency of the rod is a multiple of the natural frequency of the tube.

## Simple mechanical compass trap closures.

An interesting option for the contactor is the compass design. Dry compasses are mainly used without liquid, in them one arrow serves as a contact, and the other one or two pins mounted on the compass card. Instead of pins, you can install a reed switch. When the magnetic arrow approaches him, he closes the circuit.

A fuse with such a switch as the previous one is good for preventing munition clearance, opening a door, and stretching. When installing it on a car, an explosion is observed when the car is turned, which ensures more reliable damage to the crew.

The disadvantage is the oscillation of the compass needle, and the difficulty of its operation near massive iron structures. The gyrocompass is devoid of such shortcomings. It can be a small electric motor with a massive rotor or a flywheel suspended on a gimbal suspension.

Figure 7 shows a door handle with a test tube attached to it. Inside the tube there is a metal ball and a tube with two contacts. When you turn the knob, the ball closes the contacts. Instead of a ball, you can use mercury or salt water.