ساعات الزنبرك - الزنبرك صندوق ادخار .. الآلات التي نستخدمها كل يوم وكيف تؤدي عملها

Spring watches - Spring is a savings box .. The machines we use every day and how they work

Spring watches:

If you have ever taken apart a watch with a spring, and tried to put it back together again, you might think that it is a very complex device, its parts are really difficult to assemble. However, the way it works is very easy.

The machine of this watch is similar to the machine of the music box in many ways: each of these two machines has a spring that unwinds its coils to turn something. In the music box, the spring turns a cylinder, while the watch spring turns the wheels (gears) that move its hands. Each of the two machines contains a speed regulator, whose job is to prepare this machine to work as slowly, deliberately and organized as possible. Perhaps the watch needs this organization more than the music box. Therefore, the rotating shovel becomes incapable without managing this organization process accurately and tightly. In some clocks, it is replaced by another speed regulator called the "pendulum", and in others, it is replaced by a thin coil spring, which performs this regulation process.

We will now study how these two devices regulate the speed of the clock. The best way to study the work of the pendulum is to make one.

Bring a piece of string two feet long, then tie one end of the string to a small, heavy object such as a piece of stone, a solid ball, or a bunch of keys. Hold the string from the other end, then move it lightly so that this pendulum swings (as you see in the drawing on page 184).

Calculate the number of revolutions that the string swings in a minute, then repeat this experiment, but this time, let your movement of the string be more intense and stronger so that the string swings more than the first time. You will find that there is no difference between the number of times the string moves in the two times from a practical point of view. Whether the pendulum moves a small or a large distance, the number of revolutions that its movement makes in a minute remains constant and does not change.

The pendulum of a clock is used to adjust the movement of the spring. This spring moves the wheels (gears) that turn the hands of the clock. If we want the clock to be perfectly accurate, these gears must always move at the same speed, whether the spring is wound a full turn, a half-turn, or not wound at all. This is because the pendulum supervises and undertakes this process with the help of another precise device, the (clock hammer).

The illustration shows you that this hammer consists of two parts, one of which is a gear (wheel) with teeth inclined outwards. This gear rotates under the influence of the movement of the spring. If the gear is completely free, it rotates as it pleases, and turns rapidly without control or order, just as the gears of a toy car do. Thus, the spring is separated in a few seconds. But this gear is not in fact completely free, because it is attached to another piece in the form of a hook with a tooth at each end. This saw vibrates and oscillates by means of the pendulum. During this oscillation, each tooth of the hook is attached to the gear, one after the other. This means that the gear does not rotate unless the hook moves, and the gear continues to move for a short distance until the other tooth of the hook is attached to it. All this results in a series of regular movements. The pendulum - as you saw in your experiment - moves to the right and to the left (swings). The number of revolutions of this movement becomes constant and does not change per minute. This pendulum in turn (shakes) the hook that allows the gear to rotate - which is connected to the spring by other gears - it allows this spring to unwind its coils regularly and in small batches each time. The regular movement of unwinding the spring causes the clock hands to rotate regularly as well, and all this means that the clock becomes set.

You have noticed from your experience that the pendulum swings each time a distance that gradually shortens until it is unable to move at all at the end of the minute. What causes the pendulum to move for a long period that may reach hours or days?

This is the job of the hook. Every time a tooth of the hook's teeth meets the gear, it receives a push, sufficient for the pendulum to maintain its movement. These pushes that the teeth of the pendulum receive in succession are the cause of those gentle chimes that emanate from the clock and are a pleasure to hear.

This pendulum clock has two obvious drawbacks. First, the pendulum is a rather bulky body. This means that the case that houses the clockworks must be large. Second, this clock must always be hung or placed vertically so that the pendulum can move freely. For this reason, most of these clocks are equipped with various models of devices that regulate their speed, which require only a small space and are designed to perform their function in any position. This regulator is a thin spring that is provided by all wristwatches and most wall clocks.

If you do not have a spring to conduct your experiments with, a rubber band will do the trick. Attach a weight to one end of the rubber band, and the weight of this weight should be enough to stretch the band to half its capacity. Hold the rubber band at the other end, and give it a gentle shake. Count the number of cycles the rubber band vibrates up and down in fifteen seconds. Then shake the weight vigorously, and count the cycles of vibration. You will find that the number is almost the same in both cases. The rubber band was exactly like a real spring. All springs oscillate at the same rate and at a constant speed after they are put into action, whether by tension, compression, or winding. A watch spring oscillates by filling and emptying it. This spring is connected to a small gear called a pendulum. When this gear is wound or unwound, the spring turns the pendulum in one direction, and then in the opposite direction. The pendulum in turn moves (a device, similar to that in a pendulum clock, that is, it shakes a toothed hook that allows a gear to rotate so that one tooth is attached to this gear at a time in succession.

What makes this pendulum constantly spin and straighten? And why doesn't it slow down and then stop working just like a rubber band does? The reason for this is the presence of the same devices that keep the pendulum oscillating back and forth - namely the hook and the gear with slanted teeth: each time one side of the hook strikes this gear, the gear vibrates: and is pushed enough to allow the hairspring to spin and straighten. This movement also causes the sound of the clock that comes from the wristwatch or the wall clock and you hear it.

All these parts - the thermos with teeth - the hook - the hairspring and the pendulum - do not regulate their movement by themselves, but rather they move under the influence of a large spring called the mainspring. When you wind the clock (the wristwatch or the wall clock) Energy is stored in this main spring, which it returns when it is unwound and uncoiled, little by little each time. This process is supervised and regulated by the regular, periodic motion of winding, unwinding and uncoiling the hairspring. At the same time, unwinding the mainspring turns the hands of the clock.

Timekeeping machines must be well-made if they are not to advance or delay. Perhaps the best of them all are those types used by sailors, which are called chronometers. A good chronometer does not advance or delay more than one minute per year!

Perhaps the wrist or wall clock is the most precisely designed and manufactured of all the spring devices you see in your home.