EP1529248A2 - Device and method for testing the leak-tightness of a timepiece case - Google Patents

Device and method for testing the leak-tightness of a timepiece case

Info

Publication number
EP1529248A2
EP1529248A2 EP20030792255 EP03792255A EP1529248A2 EP 1529248 A2 EP1529248 A2 EP 1529248A2 EP 20030792255 EP20030792255 EP 20030792255 EP 03792255 A EP03792255 A EP 03792255A EP 1529248 A2 EP1529248 A2 EP 1529248A2
Authority
EP
Grant status
Application
Patent type
Prior art keywords
gas
concentration
characterized
box
device according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP20030792255
Other languages
German (de)
French (fr)
Inventor
François Gueissaz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Asulab AG
Original Assignee
Asulab AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • GPHYSICS
    • G04HOROLOGY
    • G04DAPPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
    • G04D7/00Measuring, counting, calibrating, testing or regulating apparatus
    • G04D7/006Testing apparatus for complete clockworks with regard to external influences or general good working
    • G04D7/007Testing apparatus for complete clockworks with regard to external influences or general good working with regard to the sealing of the case

Abstract

The invention relates to a device for testing the leak-tightness of a case (2) belonging to an electronic timepiece (1) comprising a time base (42) which is used to produce a standard frequency signal and a central processing unit (44) which is used to determine the time from said standard signal. The invention is characterised in that it comprises an electronic sensor (32) which can measure fluctuations in the concentration of an atmospheric gas confined in the case (2). According to the invention, the results of the measurement taken by the electronic sensor (32) are processed by the central processing unit (44) which, if necessary, emits an audible or visible alarm in response to the measurement signal.

Description

DISPOSITI F AND CONTROL METHOD OF SEALING AN E BOX OF PI ECE HORLOGERI E

The present invention relates to a device to ensure that a box of a timepiece is sealed vis-à-vis the outside. The present invention also relates to a method for monitoring the tightness of such a box. li has already been proposed to establish in a watch case a pressure greater than atmospheric pressure, so as to prevent an external pressure greater than the pressure in the box results in a penetration of water, steam, gas or dust in the box (Swiss patent No. 312740). For this purpose, the box is provided with a valve for blowing an inert gas is under a pressure of 1, 1 to 1, 5 atmosphere and a manometer allowing the wearer of the watch to know the pressure in within the box.

A pressure gauge is, however, a complicated, delicate and expensive instrument which, in case of failure of the seal of the watch case, can be damaged as well as movement, which greatly increases the reclamation costs .

To overcome these problems, it has been proposed (Swiss Patent No. 544959) to replace the gauge by a device also for verifying the maintenance of pressure in a watch case, said device comprising an elastically deformable membrane, bistable separating gas-tight manner the box of an enclosure in which there is a different pressure, and means to make visible to the user one or other of the two stable states of the membrane.

A device of the type described hereinbefore has the advantage of being relatively simple and robust enough, and be less expensive than a pressure gauge. Such a device however has the disadvantage of providing information of the all or nothing type comparable to that provided by an LED, for example. Thus, this device will pass from its first to its second stable state in which it indicates to the wearer of the watch that the latter has a sealing defect, as when the overpressure inside the watch case will have dropped of a predetermined value. So it may well be that the watch has leaks, but the pressure that prevails has not yet reached the threshold necessary to trigger the verification device for maintaining the seal. The movement can thus deteriorate without the watch of the wearer's knowledge. On the other hand, it is necessary to inject inert gas into the box with a higher specific pressure threshold of the verification device, which requires appropriate tools that all watchmakers are not likely to hold. Finally, the measurements made by such a device may be seriously marred error by variations in ambient temperature affecting the confined air pressure in the box.

The present invention aims to overcome the aforementioned drawbacks in addition to others by proposing a sealing device for monitoring a watch case that allows the holder to be alerted as soon as it begins to present leakage.

To this end, the present invention relates to a device for controlling a transmission of an electronic timepiece including a time base for producing a standard frequency signal and a central processing unit to determine the time from standard signal, characterized in that it comprises an electronic sensor capable of measuring fluctuations in the concentration of a gas of the atmosphere contained in the box, the results of the measurement performed by the electronic sensor being processed by the unit central processing means responsive to the measurement signal, emits, if necessary, an audible or visual alarm.

Thanks to these characteristics, the present invention provides a device for instantaneously alert the wearer of a watch with a sealing defect in the box at his watch. Indeed, as soon as the watch has a leak, it causes gas exchange between the surrounding air and the atmosphere contained in the watchcase and a concomitant decrease in the gas concentration of the confined atmosphere in said box, which reduction is detected by the sensor. Quickly notified of the loss of seal of the watch, the wearer can bring it in its watch which can be placed under a vacuum bell in order to test and repair, if necessary. The risks that the movement of the watch being damaged are reduced greatly.

Another advantage of the present invention lies in the fact that the gas sensor operates in conjunction with the electronic watch, using this means for generating, if necessary, an audible or visual alarm. It is not necessary to stay in the box shows additional electronic components, which allows substantial savings in terms of cost of components and assembly time and save space in the box the watch.

According to an additional characteristic of the invention, the gas sensor comprises a differential measuring bridge. Such a circuit is reliable, compact and consumes much less power that starts only for brief periods at regular time intervals. In addition, it contains no moving parts, which further increases reliability. According to yet another feature of the invention, the gas in the confined atmosphere of the watch case is a neutral, heavy gas having a different thermal conductivity than air such as, for example, carbon dioxide. After recognition of a loss of sealing of the case and subsequent repair, the watch can be easily reconditioning by a trade watchmaker. Just, in fact, while the watch case is still open, to introduce into it neutral and heavy gas whose concentration fluctuations are monitored. Thus, in the case of carbon dioxide is a gas that is readily available in the form of aerosol, no special tools are required. After completing the gas box, completely or partially, it is sufficient to close it in a sealed manner without having to worry about the concentration of said gas to the extent that the device according to the invention utilizes relative values ​​of concentration and not absolute values. The use of a neutral gas has other advantages. Thus, due to its neutrality, it can react with the components of the watch, so that changes in its concentration in the confined atmosphere of the box accurately reflect gas exchange occurring between the box and 'ambiant air. Of course, the neutral gas chosen must be non-toxic and little spread in the air, that is to say that its concentration in the box will have to be higher than its concentration in the air.

Alternatively, the inert gas may be blown into the box via a valve. This variant is particularly advantageous when one wants to instill in the watchcase neutral lighter than air gas such as helium. Indeed, it would not be possible to fill the box of such a light neutral gas by simply opening it and filling it through an aerosol because the gas would escape. On the other hand, the coefficient of thermal conductivity of helium is in a ratio of ten relative to that of the ambient air, which allows for increased detection sensitivity. In addition, a light gas such as helium diffuses more easily, which further contributes to enhance the detection sensitivity. The present invention also relates to a sealing method for controlling a box of a timepiece, said method being characterized in that it comprises the steps of:

- introducing a gas with a starting concentration in the confined atmosphere of the box; - measuring the concentration of starting of said gas;

- measuring continuously or intermittently the gas concentration, and - generating an alarm when the measured gas concentration is different from the initial concentration of said gas or where the leakage rate exceeds a predetermined value.

Other features and advantages of the present invention will become apparent from the detailed description which follows of an embodiment of the control device according to the invention, this example being given purely by way of non-limiting illustration only, in conjunction with the annexed drawing wherein:

- Figure 1 is a sectional view of a wristwatch equipped with the leak testing device according to the invention; - Figure 2 is a view of the box of the watch shown in Figure 1 when one proceeds to the gas filling by means of an aerosol;

- Figure 3 is a view of a watch fitted with a valve for blowing a gas into the watch case, and

- Figure 4 is a circuit diagram of the gas sensor and the central processing unit of the watch.

The present invention proceeds from the general inventive idea which consists in measuring changes in the concentration of a gas in a confined atmosphere in a watch case. As soon as a decrease in the gas concentration is detected, an alarm is generated to warn the wearer of the watch that it has a sealing defect. Compared to the known prior art solutions which consist, for the most part to establish an overpressure in the box of the watch and monitor a possible reduction of this pressure, the present invention has the main advantage of not constitute a system the all or nothing type that provides information when the parameter to be monitored reaches a threshold value, but rather to provide a highly sensitive system that will notify the carrier of the immediately shows that it will begin to show signs of loss of sealing. On the other hand, the system of the invention measures a relative value, not an absolute value. It is therefore not necessary to determine the initial concentration of gas at a fixed value, only the value of the initial concentration to be known. Finally, the device according to the invention is of the passive type, so it has no moving parts and is therefore very reliable.

The present invention will be described in connection with a timepiece of the wristwatch type. It goes without saying that the invention is not limited to such a watch and can be applied identically to the extent of the loss of sealing any type of timepiece. Figure 1 appended to the present patent application is a sectional view of a timepiece provided with the gas detection device according to the invention. Designated as a whole by the general reference numeral 1, this timepiece conventionally comprises a housing 2 provided with a middle part 4 and a base 6 which delimits the housing 2 in its lower part. In the example shown in the drawing, the bottom 6 is made of one piece with the middle part 4. It goes without saying however that the present invention applies equally to a box that would not monohull and that would include a separate bottom of the caseband. The housing 2 may be achieved, for example, a plastic material according to well known injection techniques. The present invention does not limited to the choice of such material and the housing 2 can be made of any material adapted to the needs of the watch industry, such as, in particular, steel.

The timepiece 1 also includes a clockwork movement 8 mounted in a casing ring 10. This movement 8 is supplied with current by an electric battery 12 which may, where appropriate, be recharged after exhaustion or replaced. The battery 12, shown schematically in the drawing, typically in the form of a pellet. It can be housed in the bottom 6 of the watch 1. The lower face of battery 12 which constitutes one of the poles thereof is electrically connected to ground of the watch 1, for example by means of a spring contact 13 attached to the bottom 6 of said watch 1. the other pole of the battery 12 which is formed by its upper side is, in the usual manner, electrically connected to the clockwork movement 8.

In its upper part, the housing 2 is delimited by a crystal 14 covering the display means 16 of a schedule information. In the example shown in the drawing, these display means 16 are composed of a dial 18 above which move an hour hand 20, a minute hand 22 and second hand 24. It is therefore analogue display means of the time. It could also include digital display means comprise a liquid crystal cell. Finally, the housing 2 comprises at its upper periphery a notch 26 in which is engaged a bezel 28 which serves to fix the glass 14 on the housing 2. The bezel 28 is fixedly mounted on the housing 2, for example by gluing or welding ultrasonic or by driving. The crystal 14 is sealed relative to the housing 2 through the use of a gasket 30 clamped between the ice and the housing. As can be seen in Figure 1, the timepiece 1 also comprises a sensor 32 housed in the casing 2. This sensor 32 is capable of detecting the fluctuations of the concentration of a gas such as, for example, dioxide atoms, of the atmosphere contained in the housing 2. the sensor 32 is preferably of electronic type, of small dimensions and low power consumption. An example of such a sensor consists of that sold by the Swiss company Microsens MTCS Products under the reference 2200. The operating principle of such a sensor is as follows. electric heating means have the role of maintaining a thermally and electrically insulative membrane forming part of the sensor to a predetermined target temperature. Depending on the fluctuations of the neutral gas concentration of the atmosphere contained in the box, the thermal conductivity of said atmosphere varies, and it is necessary to provide more or less electrical energy to the heating means to maintain the membrane in its temperature setpoint. Correspondence tables used to determine, according to the supplied electric power, the concentration of the atmosphere used in inert gas. In the case of carbon dioxide, its thermal conductivity is less than one third than that of the air, which allows variations to detect the concentration of this gas as low as 1%. In another embodiment, measuring the heat flow between the bladder and a temperature sensor, separated from one another by the gas whose concentration fluctuations are to be measured.

When the gas sensor commissioning 32, it is first necessary to carry out filling of the watch in a neutral gas. For this, two solutions are possible. The first, which is the most simple, is to open the case 2 of the watch 1 and to spray the gas therein. Thus, in the case of carbon dioxide gas which is easy to procure in the form of an aerosol canister 34 (see Figure 2), no specific tools are required. After filling the box 2 gas, simply close it tightly. Alternatively, it is also possible to provide the 1 shows a valve 36 (see Figure 3) adapted to open under the action of external pressure and comprising a pipe 38 on which can be fixed a conduit 'feed 40 of a pressurized gas.

As shown in Figure 4, the clockwork movement 8 of the watch 1 conventionally comprises a time base 42 for generating a standard frequency signal and a central processing unit 44, in particular to determine the time from the standard signal and provide driving pulses to a motor 46 which will drive the hour hand 20, minute and 22 seconds 24 via a not shown gear train. Alternatively, the central processing unit 44 may also provide electrical control signals to a liquid crystal cell to display digitally hour. According to a preferred embodiment of the invention, the pressure sensor 32 comprises a differential measuring bridge 48 which can be powered using a 50 voltage or current generator 52 and which is formed of four branches comprising each resistance, respectively 54 and 56, and connected in series. The resistors of the pair of branches which are connected in parallel with the current source are equal, while the resistors 56 of the other pair of legs have a resistance which varies depending on the inert gas concentration in the atmosphere enclosed in the case 2 of the watch 1. When the gas concentration decreases, the balance is broken between the two pairs of branches, which creates a potential difference proportional to the concentration of inert gas. This potential difference is applied to the input of an analog / digital converter 58 via a differential amplifier 60. Finally, the output of the converter 58 is connected to one of the central processing unit inputs 44 the clock 1. If the watch is provided with a liquid crystal display device, the central processing unit 44 may indicate to the user the leak rate of the watch 1. the leak rate is the ratio between pressure difference in millibars and a duration in seconds, the whole being multiplied by the volume in liters of the watchcase. Practically, to calculate the leak rate, the central processing unit calculates the difference between the last two pressure measurements and then divides this result by the time between the moments which were made pressure measurements. It remains then to the CPU to multiply this ratio by a constant that represents the volume of the watch case. The actual value of the leakage rate can be displayed on the liquid crystal display cell. May also be chosen to introduce in the memory of the central unit with a nominal value representing the maximum allowable leak rate by the clock, and to express the value of leak rate measured as a percentage of the nominal value. Similarly, for greater clarity, the central processing unit may calculate an average leak rate for a plurality of pairs of pressure values ​​measured in the past. Interest calculated leak rate is the fact that it can take an exaggerated value even when the gas concentration of the atmosphere contained in the watch case has not yet passed under the critical threshold beyond which the alarm is triggered. The user can thus, in itself, check the quality of the sealing of his watch 1 and decide if it needs to be reported in the watchmaker to end repair.

Once the gas introduced into the housing 2, the sensor 32 performs a measurement of the initial concentration of this gas, and then performs subsequent measurements continuously or intermittently. As soon as the sensor detects a variation of the inert gas concentration in the atmosphere confined in the upper housing to a predetermined value, it generates an alarm. Indeed, if the inert gas concentration varies, this means that the air entered the housing from the outside thereof. The alarm can be visual type and is displayed as a message or a symbol on a liquid crystal screen. The sensor may also control the lighting of a LED or even the transmission of an audible signal. Therefore, the wearer of the watch 1 is notified that it is defective seal and must be returned to the watchmaker end repair. The carrier is quickly informed, the risk that the movement of the watch is deteriorated greatly limited.

It goes without saying that the present invention is not limited to the embodiments described above and that various simple modifications and variants can be envisaged within the scope of the invention. In particular, it may be contemplated that the gas sensor carries out a measurement of the ambient temperature prior to measuring the concentration of the desired gas. Indeed, a timepiece is typically designed for use in a temperature range between -20 ° C and + 70 ° C. It will be understood that such temperature variations affect the pressure inside the box. By previously measuring the ambient temperature, the sensor may calculate the result of this measurement to correct the measurement of the pressure at which it will proceed subsequently.

Claims

1. Device for monitoring the tightness of a box (2) of an electronic timepiece (1) comprising a time base (42) for generating a standard frequency signal and a central processing unit ( 44) for determining the time from the standard signal, characterized in that it comprises an electronic sensor (32) capable of measuring fluctuations in the concentration of a gas of the atmosphere contained in the box (2), the results of the measurement performed by the electronic sensor (32) being processed by the central processing unit (44) responsive to the measurement signal, emits, if necessary, an audible or visual alarm.
2. Device according to Claim 1, characterized in that the electronic sensor (32) comprises a differential measurement bridge (48).
3. Device according to any one of claims 1 or 2, characterized in that the gas in the confined atmosphere of the enclosure is an inert gas.
4. Device according to claim 3, characterized in that the concentration of inert gas into the enclosure from the atmosphere is less than its concentration in the ambient air.
5. Device according to any one of claims 3 or 4, characterized in that the inert gas is carbon dioxide or helium.
6. Device according to any one of claims 1 to 5, characterized in that the enclosure is provided with a valve (36) in order to inject the gas.
7. Device according to any one of claims 1 to 6, characterized in that the sensor (32) measuring the initial concentration of gas and then measuring the concentration of continuously or intermittently and controls the production of an alarm signal as soon as it detects a fluctuation in the value of the concentration of gas greater than a predetermined value.
8. Device according to any one of claims 1 to 7, characterized in that the sensor (32) comprises electric heating means whose function is to maintain constant the temperature of a thermally and electrically insulative membrane.
9. A method of controlling the tightness of a box (2) of a timepiece (1), said method being characterized in that it comprises the steps of:
- introducing a gas with a starting concentration in the confined atmosphere of the box;
- measuring the concentration of starting gas; - measuring continuously or intermittently the gas concentration, and - generating an alarm when the concentration of the measured gas is different from the initial concentration of said gas or where the leakage rate exceeds a predetermined value.
10. The method of claim 9, characterized in that, before measuring the concentration of gas is carried out a measurement of the ambient temperature.
11. A method according to any one of claims 8 to 10, characterized in that the box is filled with gas by opening thereof, by filling it with gas and then closing the sealed manner.
12. A method according to any one of claims 8 to 10, characterized in that the enclosure is filled with gas via a valve.
EP20030792255 2002-08-09 2003-08-06 Device and method for testing the leak-tightness of a timepiece case Withdrawn EP1529248A2 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP02078340 2002-08-09
EP20020078340 EP1388766A1 (en) 2002-08-09 2002-08-09 Device and method for testing watertightness of an enclosure such as a watch case
PCT/EP2003/008672 WO2004019141A8 (en) 2002-08-09 2003-08-06 Device and method for testing the leak-tightness of a timepiece case
EP20030792255 EP1529248A2 (en) 2002-08-09 2003-08-06 Device and method for testing the leak-tightness of a timepiece case

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20030792255 EP1529248A2 (en) 2002-08-09 2003-08-06 Device and method for testing the leak-tightness of a timepiece case

Publications (1)

Publication Number Publication Date
EP1529248A2 true true EP1529248A2 (en) 2005-05-11

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ID=30129229

Family Applications (2)

Application Number Title Priority Date Filing Date
EP20020078340 Withdrawn EP1388766A1 (en) 2002-08-09 2002-08-09 Device and method for testing watertightness of an enclosure such as a watch case
EP20030792255 Withdrawn EP1529248A2 (en) 2002-08-09 2003-08-06 Device and method for testing the leak-tightness of a timepiece case

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP20020078340 Withdrawn EP1388766A1 (en) 2002-08-09 2002-08-09 Device and method for testing watertightness of an enclosure such as a watch case

Country Status (6)

Country Link
US (1) US20050270908A1 (en)
EP (2) EP1388766A1 (en)
JP (1) JP2005535902A (en)
KR (1) KR20050035874A (en)
CN (1) CN1675598A (en)
WO (1) WO2004019141A8 (en)

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EP2770380A1 (en) * 2013-02-21 2014-08-27 The Swatch Group Research and Development Ltd. Electronic device provided with an automatic leak detection means
EP2770315A1 (en) * 2013-02-21 2014-08-27 The Swatch Group Research and Development Ltd. Electronic device provided with an automatic leak detection means
DE102015200549A1 (en) * 2015-01-15 2016-07-21 Zf Friedrichshafen Ag Circuit device and method for monitoring a circuit device
DE102015204613B4 (en) * 2015-03-13 2018-03-15 Levitation AG A method for manufacturing a watch glass with at least one gem
CN106017804A (en) * 2016-05-26 2016-10-12 青岛海尔股份有限公司 Refrigeration and freezing apparatus airtightness inspecting method and refrigeration and freezing apparatus
CN106404313A (en) * 2016-09-18 2017-02-15 惠州Tcl移动通信有限公司 Method for testing IPX7 performance of waterproof device and waterproof device

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Also Published As

Publication number Publication date Type
WO2004019141A8 (en) 2005-02-10 application
EP1388766A1 (en) 2004-02-11 application
JP2005535902A (en) 2005-11-24 application
CN1675598A (en) 2005-09-28 application
WO2004019141A2 (en) 2004-03-04 application
KR20050035874A (en) 2005-04-19 application
US20050270908A1 (en) 2005-12-08 application
WO2004019141A3 (en) 2004-07-15 application

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