Do-it-yourself stopwatch repair

Our watch workshop repairs not only wrist, floor and wall clocks. The range of services also includes the repair of alarm clocks, stopwatches, pocket watches.

The difference between alarm clocks and table clocks is a device for signaling at a specified time. Alarm clocks are:

• Mechanical.
• Electronic-mechanical.
• Quartz.
• Electronic.

The pocket watch is powered by a mainspring located in the drum.

The stopwatch mechanism is no different from conventional watches. But there is an additional mechanism to return the arrows to their original position.

The following defects occur in the stopwatch mechanism.

1. Due to the fact that the crown is fixed on the thread, and the threaded part of the shaft is pointed, during the winding of the stopwatch spring, the crown may sink deeper along the thread, which will shorten the working part of the shaft somewhat.

In this case, you should unscrew the head and put a piece of metal into the head sleeve, from which the head will rise higher.

2. Crown wheel lining worn out. This causes the repair wheels to crackle. It is necessary to lower the screw of the crown wheel or replace the lining.

3. The double heart repositioning hammer does not come close to the hearts. In this case, it is necessary to slightly rivet the ends of the hammer or file off the ledge that interacts with the column.

4. There are cases when the stopwatch complication is in perfect working order, however, when the hands are reset to zero, the second hand does not reach its original position and each time it moves further and further away from the zero position. It is necessary to strengthen the second hand on the tube or squeeze the tube of the second hand so that it fits more tightly on the heart sleeve.

5. In the case when the arrow rises and does not rotate with the axis, remove the fixing spring and slightly deepen the notch of the sleeve so that the spring enters deeper into the groove. This improves the fixation of the heart • on the axis.

In some stopwatches and watches with a stopwatch, chronograph wheels are used, with which cores are mounted on the same axis, designed to return the hands to the zero position. This assembly (chronograph wheel, heart and hand) must be balanced by drilling a hole in the sector of the wheel.

If the hands are removed tightly, then the dial is removed together with the hearts and with the hands. Hearts that do not require special repairs are cleaned with a dry brush. The holes of the hearts are cleaned with a pointed chock and blown with a rubber bulb. If the arrows are not removed, then when disassembling the mechanism, the lever of the double hammer is removed from the heart during the installation of the dial.

During the assembly process, the pins of the axles and the working surfaces of the trigger mechanism are lubricated with oil. When adjusting the starting device, it is necessary to achieve the movement of the locking pin in an arc so that the pin, after the release of the balance, would give the initial push to the balance. To small

the friction spring worked reliably, it is necessary to ensure its proper pressure on the axle. For these purposes, often resort to its additional bending.

The landing of the arrows must be with the proper interference. Arrows are set at the zero position of the hearts.

Where to begin. Some notes from Bogdan Ya.

This is purely an experience of an amateur who has never been a professional watchmaker. Accordingly, all this is suitable for an amateur. The road to a professional is in the school. Everything will be taught there.

Start with Pinkin. Or from Troyanovsky. In general, there are books on the topic of watch repair. Download and print.Okay, there is no Internet - everything will be done for you in any Internet cafe. You must have the book. It might be expensive, but it's worth it. This book is a guide for the non-professional who should be able to understand at least something from this book. Almost our case. I have never done anything like this before - and here it is.

We will make some additions with the amendment for today for those who are pinned down.

Screwdrivers. Start simple.

Chinese. I use. I'm sharpening. As for Chinese screwdrivers, look where they change watch batteries on the streets and sell batteries and watch straps. Or in the most ordinary households. Screwdriver set for small jobs.

You take a screwdriver. If it turns out to be too soft and bends when you try to unscrew something, you put a candle next to the screwdriver. You heat the blade of the screwdriver and quickly into the wax. This is hardening. Then you take a small stone and, according to Pinkin, you sharpen it.

More cool - in the machine on a diamond disk. But it will be later. When the tool and machines appear. Well suited stones for finishing.

Tweezers (for starters, medical eye tweezers will do).

An alternative is to get acquainted with the radio bazaar (if Moscow, then it seems Gorbushka - where they sell radio components, radio stations and computer bells and whistles) - see the boxes where the instrument is sold. You will be greatly surprised by the abundance. Good tools are surprisingly expensive. Forms of tweezers - see Pinkin. I'm not talking about big watchmaking workshops. They'd rather be beaten than sell something at a normal price. They do not want to produce competitors. And if they sell, then the prices are simply unrealistic. Doesn't go through any gates.

There is also a radio market - Galosh gasoline. Wash. It is much drier than kerosene and white spirit.

You take chopsticks (like Chinese ones) - finger length - to taste. You stick a fishing steel 3-4 cm long into the end - it can be thicker and thinner. 0.1 - 0.15 mm. This is for the fishermen. One meter is enough for 10 years of work.

The very tip is splashed with one blow of a hammer (through a punch or a hard piece of iron) on a hard anvil. You get a small spatula. You make 3-4 of these with different blade sizes and different steel diameters. This will replace the oil dosage. As anvils, I use either a roller from a large bearing or carbide plates for a lathe - your way to a flea market or to friends in a workshop.

In approximately the same way - for a start it will come in handy - sticks with ordinary sewing needles - while the hands are cowardly and there are no good tweezers - exposing parts (gears to stones, screws, etc.) is an auxiliary tool.

Surgical clamps. Different. Very handy as small and strong pliers. Bought usually on occasion at a flea market.

Dental spatulas. It is convenient to use in all cases as an auxiliary tool.

Enema. Rubber. From the pharmacy. Big. Blow off the dust. The tip must be rubber.

Butter. Or in the workshop (if they don’t beat you, although they usually look like sheep and pretend that they don’t understand what you are talking about and try to get you off as soon as possible). Or maybe at the radio bazaar - in the same place where solder and acid are sold. Oil MN-30, MN-45 or watch oil. Although it is not aerobatics, it will do for a start.

It is better to keep it in a dark heavy box - and the sun will not burn and there is less chance that it will turn over.

To open the cases - a large broken medical tweezers. It is clear that this is not kosher - but it is also possible. Likewise - the old caliper. Only it is necessary to correct the edges of the sponges - so that they are more rectangular.

Scalpel - opening cases.

Binocular loupe. It is relatively inexpensive, but without it it is better not to even start. Or photographic goods (classic - where they sell spyglasses and binoculars) or a radio market. There are different strengths. If you have money, take two. One 1.5 times, one - the strongest one for sale - seems to be up to 2.5 times.They can be sold on an elastic band - you will have to redo it for a hard rim. You can go talk in the workshop of optics - glasses. Maybe they'll offer something like pince-nez. As for ordinary magnifiers - to taste - I rarely use them. It turned out to be extremely useful for cutting the cub's nails - they were not visible at all for the first six months, but they need to be cut.

Binocular microscope. Yes. Old. Look. The oldest one is MBS-1. It has a straight image - not upside down - which is what we see. Should cost around $ 50. A very useful thing. In every way. Up to the point of tearing the skapka out of your finger. But this is on occasion and over time. MBS-10 or OGMZ are cooler - the distance from the object to the eyepiece is greater, it is clear that it is more expensive. But still, under the MBS-10, an ordinary screwdriver does not fit - you need to shorten it. Although on the website of the Lytkarinsky plant - the manufacturer of the MBS-10 there is a link that they sell lenses with an object distance of about 19 cm for the MBS-10. This may be a good solution if we got the MBS-10. Everything between MBS-1 and MBS-9 - consider the same. Over time, the lens can be redone yourself. Take whatever is cheaper. It's closer to the flea market. The only thing is that it is desirable that there be an illuminator (transformer + light bulb).

Everything that is further from the tool - only after evisceration 4-5 hours.

Where to get a watch - get yourself a fashion to visit a flea market - everything floats there. Often they just sell mechanisms. For instance:

When you warm up a little - after buying a binocular microscope - there is also a radio market, shops with tools - they usually sell ultrasonic washers. But here, too, the question is whether it is necessary. 50 years before that they had not been used - they took a bath and washed the parts in gasoline with a brush. You can get by, but the weight is good. Should cost in the range of 50-80 $. Denatured alcohol and Galosha gasoline were poured into the ultrasound of 30 watts. Working. Doesn't flash. Washes like a beast, but still sometimes you need to tear something off with a toothpick. They say in the bazaar that 30-watt sinks - indestructible - work without problems and there is no return due to marriage. If the model is as shown in the picture - what should be done after purchase - disassemble completely (moisture may turn out to be inside, one of the indicators is stylish clicks when working against a uniform sound), squeeze the metal tank out of the case and put it back on the Auto Sealant (white , ours, not on transparent silicone). Plumbing does not pass - highly corrosive. One of the indicators of plumbing is a strong acetic smell.

Yes, I forgot, a flea market - look for Petri dishes - or maybe in a pharmacy or in a laboratory at a hospital. But you are not their client - there is an expensive flea market - that's it. These are flat round glass or plastic low trays - for details. They are cheap. Take 5 pieces for current disassembly work. I like glass ones more - they are heavier, they fidget less on the table.

Then, for convenience, in offices that make business cards, you can sometimes drive up and buy boxes for business cards. Wholesale will cost within $ 0.30 pcs. Transparent ones are also a very convenient thing - but this is for longer storage.

silica gel. Small bags that are invested in new fashionable shoes, equipment, components for computers. Absorbs water. It is necessary to dry either in the microwave or at a good temperature - in an electric oven. Gas does not pass - when the gas burns, water is released. After drying, the bag is placed in a box in which small tools and spare parts are stored for a long time - so that they do not rust.

Radiobazar. Snap bags - they sell by the hundreds. Size 4 X 6 cm. Lay down watches and small items. They usually pack small pieces that are sold at the bazaar.

To begin with, a watch can be placed on the mesh from a meat grinder during disassembly. Then you will decide what you need and how you feel more comfortable. The stand can be machined from brass. Should be heavy enough.

Take a coil from any old starter from electricians - try asking for 380 volts. If not, go to 220v.You attach the wires - the demagnetizer is ready. Turn on only for a short time - it heats up.

About the new instrument. It's not always worth the money. Think about how to get out of what you have. It is needed if you earn a living by doing this and the customer pays for everything. If this is a hobby, then not in the first place. Calculate the expenses like this: I quit smoking (and drinking) and all the savings are for the instrument. In this case, it is really a hobby and a useful pastime.

Now the steepness has gone. Machine.

Option 2. High-speed machine. 10,000 revolutions. We sharpen with a diamond file. It may well be. There are eagles who did something in this way. But as for me, this is not very correct. If you sharpen, then sharpen.

Given the above - if you do not sharpen the axles how to fry pies - then for a non-professional turner-watchmaker it would be more appropriate to take a small-sized precision universal machine. I would say that 20% of the work is turning axles (or even less), 80% is turning screws and body parts, various minor milling work.

Examples I would name are:

Collet chuck, native collets. On top is a cutting corner. A part of the caliper is attached to it and we get a “milling cutter”.

- new - Proxxon PD-230 / E, there is also a milling attachment or milling cutter FF-230. Look for them there, they even have a price list in the power tool section - that is, they really do this.

Regarding the old MD-65. Axis 0.1 sharpens. Doesn't hit. Any further explanation is unnecessary.

Now the next topic. Okay. We got a machine. Well qua. We have a type of computer in the form of a processor, monitor and keyboard. But all this locomotive needs software. Windows-2000 or Windows-XP and for tough peppers, Linux will do. So, the most interesting begins. Software often costs more than hardware. The same story with machines. Requires accessories and additional tools. An approximate set of additional personal belongings to the machine, I think, will cost no less than the cost of the machine. Now we are talking about turning + milling. My MD-65 turned out to be with a milling corner plate - a milling cutter is clamped in the machine chuck, and the support is turned over a la milling table, only vertical + milling vice. It turns out to mill arrows on it. Cut slots in the screws too.

- incisors - at least a hundred. Fits well in old wooden school cooking boxes.

For precise sharpened incisors, old boxes from under grandmother's silver spoons go very well - incisors are more expensive than spoons, they will not be beaten.

- collets and collet chuck. I have 2 sets - one native from MD-65 (3-13 mm), the second set - Lorsch (hour, 0-6 mm).

This is in the machine, Lorsch in the adapter.

- indicators. At 0.01 and 0.001. It is clear that various fasteners are needed for them. Often you have to do the fastening yourself.

– centrifuges – 0.01. Without it, there is simply nothing to do on the machine.

- Binocular microscope. Without words. We have already talked about this above.

- 4-jaw chuck. With separate unclenching of the cams.

- whetstone - sharpen cutters roughly

– diamond wheels – sharpen cutters precisely

– swivel vice (horizontal swivel system) – drill holes in precisely defined places. Screw holes in the rim of the transparent case back. It's hand drilled. It can be seen that the screws jump.

- dividing head Or with disks or with vernier. Cutting gears. Or at least make a square.

- I'm not talking about cutters. Both face and for gears. Thickness of disc cutters - from 0.1-0.15 - this is the thickness of the Neva blade.

- measuring tool - this is for rough work

- and for accurate - only optics

- then you need to look at what you need already according to the work performed. You have to do a lot yourself. Think of a lot. Very often, for the manufacture of one part, more time is spent on making a clamp in order to clamp this part into the machine.

Cutting the foil - making a "disk" arrow. Handy materials.

Now the conversation is where and how to organize it all. Must be dry. No dust. Not on the head of the family - the family must know that this is yours - and no matter what you do there - they have no entry there. And howling about the noise from the workshop is also nothing. Their comments are inappropriate (oh, it's dirty, oh, it stinks of gasoline).

At one type I saw a German machine - the type of our school one. More precisely, only pre-war. He mounted it under the kitchen table. In the center of the table is a shelf with a machine on it. The top board of the table rises - like in old school desks. He lowered the board, put the tablecloth in place and crumbled the onion with sausage. All the same, there will be no large turning work at home - everything is some kind of small shadow.

If we are talking about a large workshop or a more serious restoration work for the soul, then in addition to a small machine, you need to look towards a larger machine - a school one (I don’t want to name the type - there are many different ones), a horizontal milling NGF-110 and a muffle furnace - this is for more rough work and making fixtures. It is clear that this all needs a trailer of fixtures and tools. Photo of the basement in the country.

If you can order or buy somewhere, look towards the rollers. They can be quite expensive. Sometimes they are very helpful. Especially in the manufacture of new parts, arrows and linings for the cutters of a lathe.

As a conclusion, let's say this - this process is endless. There was a good point in one sensible book on choosing a watch lathe that is fully applicable in our case - we are all mortal. All these tools are of interest only to us. Personally. There is no reason to expect that someone after us will continue with fire in the eyes of what we started. The whole instrument must be bought on the basis that after us, our grateful descendants will die of all this rubbish and quickly. They can throw it in the trash too. They needed a place for a geranium! It is necessary to make sure that they can get more for it, slowly and confidently all this numerous relatives and offspring must be explained that all this is expensive and that in remote times it will be possible to earn something. And accordingly, if you already buy, then buy a liquid instrument, which will have a price even in 50 years. This is on the one hand. On the other hand, we are all working now. We earn something. This is just the right time to prepare a circle of activities for ourselves at a time when our earnings will decrease, that is, in retirement. Good luck.

Stopwatches are devices designed to measure small periods of time, on the order of tens of seconds and fractions of a second. Depending on the purpose of the application, stopwatches are 4 one-hand and two-hand, three-, six-, ten- and thirty-second, sixty-second, etc.

The constructive scheme of a conventional single-hand stopwatch with respect to the arrangement of the main components (engine, transmission, balance regulator) is similar to the schemes of wrist and pocket watches. However, the start, stop and reset of the hands to zero is carried out by a special mechanism located under the dial and called the complication.

When stopping and starting the stopwatch, braking and releasing the balance are carried out. This type of stopwatch is called an intermittent stopwatch.

There are also stopwatches with a continuous stroke, in which the mechanism runs continuously, and the complication turns on and off only the pointer mechanism.

Usually the stopwatch dial contains 60 second divisions, less often 100 divisions. At the top of the dial there is a small scale with divisions of 10, 30 or 60 min. In the center of the dial there is a hole into which the bushing of the second heart enters, the second hand is mounted on this bushing. On the small scale of the dial there is a minute hand, which is mounted on the sleeve of the minute heart.

The stopwatch runs intermittently.The stopwatch is started by pressing the crown, which, through the winding roller, transmits the movement to the starting lever.

When the crown is pressed again, the stopwatch stops, and when pressed a third time, the hands return to their original position.

On fig. 211, a the complication of the mechanism is shown at the moment when the hands are in the zero position.

The lever system of compression (Fig. 211.6) is controlled by a ratchet wheel 5 with twelve teeth, carrying four columns.

To start the stopwatch, press the head with your finger, which causes the ratchet wheel to turn with the start lever. 2, when the crown is released, it returns to its original position together with the lever under the force of spring 7.

Lever arm 2, descending with its lower plane, turns the ratchet wheel by one tooth, at this time the spring 6 ratchet wheel falls on the next tooth. During the rotation of the ratchet wheel, its first column will also turn to the right. The latter, in turn, presses on the ledge a double hammer 8 and lifts it up so that it springs 11 clings to hearts. ledge a mounted on a raised corner of the first column, thanks to which the double hammer releases the hearts 9 and 10.

Simultaneously with the rotation of the ratchet wheel, the balance brake 12 under the action of a spring 14 with its protrusion from the second column falls into the depression between the second and third columns and releases the balance 15, pinned 13.

Thus, the stopwatch is set in motion: the hearts began to rotate, the second and minute hands rotate with them.

Rice. 211. The position of the stopwatch switch:

o - when setting the arrows to zero; 6 - with the stopwatch on; v - when the mechanism stops: 1 - winding roller; 2 — starting lever; 3 — shoulder screw; 4 — starting lever column; 5 - ratchet wheel with four columns; 6 - thrust spring; 7 - starting lever spring; 8 - double hammer; 9, 10 - cores; 11 - double hammer spring; 12 — balance brake; 13 — brake pin; 14 — brake spring; 15 — balance; 16, 17 — spring of hearts; G - when the arrows return to the zero position; 1 - heart; 2 - double hammer plane

In order to stop the stopwatch mechanism, press the crown again, the lever will lower and move the ratchet one tooth forward, at this time the protrusion a double hammer will be in the middle of the plane of the first column, and the brake protrusion falls on the corner of the third column. way pin 13 will sink and slow down the balance 15 (Fig. 211, c). The mechanism will stop and the double hammer 8 will remain in the raised position.

To return the stopwatch hands to their original position, you need to press the crown a third time, while the lever will turn the ratchet wheel by one aub, while the protrusion of the double hammer 8 falls into the hollow between the first and second columns. Thereby double hammer 8 under the action of a spring and descends, hitting the planes on the hearts 9 and 10.

The design of the nodes of the minute and second hearts is the same. Heart springs 16 and 17 with one end they enter the recess of the axis and with the other they touch the sleeves of the heart, fixing the heart on the axis. In addition, the spring in this case acts as a friction clutch. So the springs 16 and 17 perform two functions: they press the heart to the axis, ensuring the rotation of the heart along with the axis and do not allow the heart to arbitrarily rise up.

The stopwatch complication returns to its original position. (The correct position of the plane of the double hammer in the zero position is shown in Fig. 211,d).

STOPWATCH REPAIR

The following defects occur in the stopwatch mechanism.

1. Due to the fact that the crown is fixed on the thread, and the threaded part of the shaft is pointed, during the winding of the stopwatch spring, the crown may sink deeper along the thread, which will shorten the working part of the shaft somewhat.

In this case, you should unscrew the head and put a piece of metal into the head sleeve, from which the head will rise higher.

2. Crown wheel lining worn out. This causes crackling of the strapping wheels. The crown wheel screw should be lowered or the lining replaced.

3. The double heart repositioning hammer does not come close to the hearts. In this case, it is necessary to slightly rivet the ends of the hammer or file off the ledge that interacts with the column.

4. There are cases when the stopwatch complication is in perfect working order, however, when the hands are reset to zero, the second hand does not reach its original position and each time it moves further and further away from the zero position. It is necessary to strengthen the second hand on the tube or squeeze the tube of the second hand so that it fits more tightly on the heart sleeve.

5. In the case when the arrow rises and does not rotate with the axis, remove the fixing spring and slightly deepen the notch of the sleeve so that the spring enters deeper into the groove. This improves the fixation of the heart on the axis.

In some stopwatches and watches with a stopwatch, chronograph wheels are used, with which cores are mounted on the same axis, designed to return the hands to the zero position. This assembly (chronograph wheel, heart and hand) must be balanced by drilling a hole in the sector of the wheel.

If the hands are removed tightly, then the dial is removed together with the hearts and with the hands. Hearts that do not require special repairs are cleaned with a dry brush. The holes of the hearts are cleaned with a pointed chock and blown with a rubber bulb. If the arrows are not removed, then when disassembling the mechanism, the lever of the double hammer is removed from the heart during the installation of the dial.

During the assembly process, the pins of the axles and the working surfaces of the trigger mechanism are lubricated with oil. When adjusting the starting device, it is necessary to achieve the movement of the locking pin along an arc so that the pin, after the release of the balance, would give the initial push to the balance. In order for a small friction spring to work reliably, it is necessary to ensure its proper pressure on the axle. For these purposes, often resort to its additional bending.

The landing of the arrows must be with the proper interference. Arrows are set at the zero position of the hearts.

REPAIR OF CHRONOGRAPHS

Chronographs or watches with stopwatch devices are a complex combination of a watch and a stopwatch. They are usually activated by pushing the crown, the first push activates the chronograph hands, the second push stops them, and the third resets the hands to zero.

Modern wrist chronographs are usually equipped with two control buttons. One pusher controls the start and stop of the chronograph stopwatch, and the other pushes the hands back to zero.

When repairing chronographs, they are disassembled in a certain sequence.

After removing any part, you should store it only together with its screws.

When disassembling, you should not touch the eccentric screws, since, having pulled them out of place, it is necessary to adjust them again, which is very difficult. Chronographs are also cleaned very carefully so as not to move the eccentric screws.

In a chronograph, most of the springs are under tension, and therefore, when disassembling, you must first carefully loosen the springs.

The fine teeth of the chronograph wheels, in addition to the usual cleaning, are additionally cleaned with a glass brush to a shine.

During cleaning, special attention should be paid to the holes in the center wheel tribe and in the levers.

The holes are cleaned on both sides with a wooden chock so that it passes through.

At the end of cleaning, the holes are blown with a rubber bulb.

The assembly of chronograph mechanisms is carried out after the assembly of the watch mechanism.

Before assembly, each part should be lightly lubricated with oil: the holes of the pins, the shoulders of the screws that are in contact with the levers, and the places of the springs that touch the levers.

When assembling chronographs, the column wheel is first installed, and then the friction spring of the central chronograph wheel is put in place.

Carefully install the chronograph wheel on the axis of the second wheel, while pressing lightly on the lower through stone.

It is necessary to ensure that the chronograph wheel, mounted on the axis of the seconds wheel, correctly engages with the intermediate chronograph wheel and is in the same plane with it. If the wheel is fixed too high on the second axle, it must be slightly lowered down to the specified height, and if the wheel is set low, it must be removed and the hole in the wheel slightly pulled off.

Next, they assemble the starting lever and check the correct operation of it, put in place the bridge holding the upper trunnions of the two wheels indicated above. The return lever is installed, but the spring in contact with the return lever must first be put in place.

Every detail must be checked during installation and then the fully assembled chronograph movement must be checked.

The ease of rotation of the intermediate wheel is checked by a jet of air directed from a rubber pear to the side planes of the teeth. When installing the center chronograph wheel, it is recommended to check the position of the friction spring.

The tension of the spring must be such that the chronograph center wheel moves away from the wheel with which it engages, and not closer to it. Never touch the teeth of the chronograph wheels with a metal tool as they can be easily damaged.

Mechanical devices for special purposes.

Chronograph “Slava”

Watch with a chain in a premium box with the coat of arms of the USSR

30-minute counter shifted to the left. Blued hands, lacquered dial. The accuracy of the measurement scale is 1/5 second.

Column-wheel chronograph movement with 19 jewels.
One-button control “start-stop-reset”.

Tachometer 9ChP

The specialization of the Third Moscow Watch Factory (3 MChZ) was the production of watch devices and military devices, such as bomb timers, on-off time recording devices, etc.
This is a device for measuring the speed of a shaft (for example, an engine). When you press a button, it starts ticking (the sound is really very similar to a bomb) and counts the revolutions of the rotating shaft.

The rotational movement is fed to a large shaft, and is transmitted through a worm gear to a counting device with an arrow. To solve the problem of the direction of rotation, an overrunning clutch is used, the same as in a modern automatic watch winder. In whichever direction the shaft rotates, the arrow moves in one direction.

By pressing the button, an accurate measurement of the number of revolutions is made (taking into account incomplete shares) in 5 seconds, the device extrapolates the value for a minute.

Inside is a rather complex device, something like a programmer. The program is set by the teeth on the escape wheel, some of them are omitted, actually intentionally. Control from the programmer - cam levers.

Device operation algorithm:
1. pressing the button - spring charging
2. releasing the button - start the balance
3. the programmer is turned on, the escape wheel with skipped teeth
4.Three clock balance programmer stabilizes the course of the watch device
5. on the fourth cycle, the velvet wheel for measuring revolutions is connected
6. The counting device measures the number of revolutions in 30 balance cycles (5 seconds)
7. The programmer stops the measurement by blocking the RPM wheel
8. after two more cycles, the programmer stops the balance

The stopwatch mechanism, like a regular watch, has a spring motor, a wheel gear, a stroke and a regulator.In addition, the stopwatch has an additional mechanism for controlling the arrows, which is called compli-nation.

Depending on the number of second hands, the nature of their action, the principle of operation of the clock mechanism, stopwatches are divided into several groups.

SOPpr - single-hand stopwatch of simple action: mechanical control of the hands with interrupted operation of the clock mechanism.

SOPRnp-r - single-hand stopwatch of simple action, mechanical control of the hands with uninterrupted operation of the clock mechanism.

SOSpr - single-hand summing stopwatch, mechanical control of the hands with interrupted operation of the clock mechanism.

SOSnpr - single-hand summing stopwatch, mechanical control of the hands with continuous operation of the mechanism,

SDPpr is a two-hand stopwatch of single action, mechanical control of the hands with interrupted operation of the clock mechanism.

SDPnpr is a two-hand stopwatch of single action, mechanical control of the hands with uninterrupted operation of the clock mechanism.

SDSpr is a two-hand summing stopwatch, mechanical control of the hands with interrupted operation of the clock mechanism.

SDSnpr is a two-hand summing stopwatch, mechanical control of the hands with uninterrupted operation of the clock mechanism.

The number of scales, capacity and division value of second scales, seconds and minutes counter scales can be different. Stopwatches are produced in two calibers: 42 and 54 mm and, depending on the accuracy of the movement, are divided into three classes.

The simplest and cheapest is a single-hand stopwatch. The stopwatch mechanism has a caliber of 43 mm, an anchor passage on eleven ruby ​​stones. The stopwatch has a second hand for counting seconds and fractions of a second and a minute hand for counting minutes on a scale with 30 divisions. The second scale is divided into 60 large divisions corresponding to seconds. Each major division contains five minor divisions corresponding to 0.2 s each. The second hand moves in leaps and bounds. Each jump of the second hand corresponds to 0.2 s.

On fig. 75 shows a diagram of a stopwatch. The stopwatch works as follows. To start the stopwatch movement, you need to press the crown. The second hand will begin to move across the dial. If the crown is pressed a second time, the movement and hands will stop. A third push on the crown will return the hands to zero position.

The complication of the stopwatch mechanism is located on the platinum under the dial. In the initial position of the complication (Fig. 75, a), the arrows are set to zero and are stationary. With a sharp press on the crown, the movement through the shaft 1 is transmitted to the trigger lever 15, which performs translational movement along two guides. One of them is the cylindrical part of the screw 14, and the other is the pin 2, sliding in the groove of the platinum.

The complication lever system is controlled by a column wheel 12, which has four columns, and a ratchet wheel with twelve teeth located under it (not shown in the figure). When turning the ratchet wheel with the trigger lever 15 by one tooth, the column wheel turns clockwise. The position of the ratchet wheel is fixed by a flat spring 10.

Spring 3 returns the trigger lever 15 to its original position. The brake 9 of the balance 6 is acted upon by the spring 7. Therefore, when the column wheel is turned, the protrusion b of the brake 9 jumps off the column 11 of the column wheel and pushes the balance of the clockwork, which was stopped by the pin 8. From this moment, the balance 6 begins to oscillate, i.e. the mechanism is set in motion. At the same time, column 1 of the column wheel raises the double hammer 13 - protrusion a is in the extreme right position on column 1 (Fig. 75, b).When the double hammer is lifted, hearts 4 and 5 are released and the arrows begin to rotate. The spring 11 of the double hammer 13 always tends to turn it clockwise.

To stop the stopwatch, you need to make a second press on the crown, while the lever 15 will turn the fastenings of the hearts of the ratchet wheel by one more tooth. The protrusion of the balance brake under the influence of column 111 of the column wheel will turn around its axis, rise to the column of the column wheel and brake the balance 6 with pin 8 - the mechanism will stop. When the column wheel is turned, the protrusion a of the double hammer slides over the column 1 and remains in the upper position on the column.

a - the position of the stopwatch complication at the moment the hands are set to zero, b - the position of the stopwatch complication during the operation of the mechanism, c - the position of the stopwatch complication when the mechanism stops; 1 - winding shaft, 2.8 - pins, 3 - trigger spring, 4, 5 - minute and second hearts, c - balance, 7 - spring, 9 - brake, 10 - flat spring, 11 - double hammer spring, 12 - column wheel, 13 - double hammer, 14 - screw, 15 - starting lever, 16, 17 - springs

To return the stopwatch hands to zero (Fig. 75, c), you need to press the crown a third time. In this case, the starting lever will turn the ratchet wheel by one more tooth, and the double hammer 13, under the action of the spring, will fall into the cavity between columns 1-11, hitting the minute and second cores 4 and 5 with ends c and d. These parts have the same design. They are fixed on their axles with the help of springs 16 and 17. One end of the spring enters the axle recess, and the other end touches the core bushing, tightly pulling it to the axle.

The stopwatch hands are mounted on the corresponding bushings of the hearts. When the mechanism is turned on, the axes of the hearts rotate due to the unwinding of springs 16 and 17.

With each blow of the hammers on the cores, a torque is created that overcomes the resistance of the springs, as a result of which the arrows return to their original position.

The balance of the stopwatch is braked when the crown is pressed a second time and remains in this position until a new start, which occurs only after the hands return to the zero position.

When the crown is pressed a third time, protrusion b of the balance brake slides over column 111, holding the balance with pin 8.

Stopwatches of the SDS type are intermittent stopwatches, in contrast to continuous stopwatches, in which the balance does not stop.

Two-hand stopwatches with two second hands are widely used. With the help of these stopwatches, you can measure the time of any two phenomena or processes started at the same time. The two-hand stopwatch SDS is produced by the 2nd Moscow Watch Factory. Movement caliber - 54 mm. It has an anchor passage, 22 ruby ​​stones are used as supports.

The second scale of the dial 2 (Fig. 76) has 30 divisions: a full turn of the second hands takes 30 seconds. Each second division is divided into 10 small divisions corresponding to 0.1 s each. The second hands move in leaps and bounds. The jump of the second hand corresponds to one small division, or 0.1 s.

Rice. 76. General view of the SDS stopwatch:

1 - minute counter hand, 2 - dial, 3 - button to start and stop the stopwatch, 4 - main stopwatch hand, 5 - crown, 6 - stop button of the auxiliary hand, 7 - auxiliary hand

For ease of use, the second hands are made in different colors - black and red. To start both second hands, press button 3. The red (auxiliary) stopwatch hand is stopped by pressing button 6. In this case, the black (main) stopwatch hand 4 will continue to move. The black hand is stopped by pressing the button 3 again. To return the black hand to its original zero position, press the crown 5.When the start button 6 is pressed again, the red hand takes its original position under the black second hand, regardless of where it is on the dial at this time, moving or stopped.

The SDS stopwatch allows you to sum up the readings of the second hand, i.e. start and stop it without returning to the zero position.