EP0741344B1 - Security device with acoustic alarm - Google Patents

Description

The present invention relates to a device for security with waterproof acoustic alarm. More particularly, this invention relates to a device security alarm which is small and which can be worn on the user's wrist, for example in the form of a wristwatch.

Nowadays, the security of people is unfortunately become a very worrying problem, especially in urban areas. In particular, people lying alone in dark streets or parking lots may feel strongly in danger. It is therefore desirable to have an easy-to-use acoustic alarm trigger and able to provide a very loud sound in order to scare away possible attackers and warn third parties in the vicinity, in order to obtain assistance the as fast as possible.

We already know security devices with alarm acoustic. Indeed, document US-A-4 806 911 describes a portable alarm security device made under shape of a key ring comprising a piezoelectric vibrator, an oscillator, a driving circuit for vibrate the vibrator, and means to activate the alarm. However, the device described is not waterproof. In addition, the alarm cannot easily be engaged if the device is in the pocket the user.

Document GB-A-2 267 374 describes a device for security with portable acoustic alarm, which is integrated in a piece of jewelry, for example a wristwatch. The device also includes a piezoelectric vibrator, an oscillator, a driving circuit for vibrate the vibrator, and means to activate the alarm. The fact that there is a speaker provided on the visible side of the room harms the aesthetics of the device. In addition, the wristwatch described does not appear not be waterproof. Anyway, no indication is given on the construction of the device itself.

Furthermore, wristwatches comprising a audible alarm device are already known. However, these are normally alarm clocks in which the noise level to be achieved is not comparable to that essential for a security. For example, GB-A-2,066,525 describes an alarm watch including a piezoelectric vibrator mounted on a metal membrane. The watch includes a drilled bottom to allow vibration of the whole membrane vibrator. The bottom is mounted so that a volume air remains between the membrane and the bottom itself. Thus, a resonance cavity is produced which allows to obtain a resonance at the natural frequency of the vibrator. The holes in the bottom allow air, and therefore sound to escape. The efficiency is then increased and a higher sound level can be obtained. Others examples of such alarm clocks are known to documents CH 537 033 or JP-A-55 080082.

As the bottom of this alarm clock device is pierced, water and impurities that it carries or others pollutants can enter the device in thus facilitating the creation of bacteria in the cavity of resonance. If these bacteria are not removed, i.e. if the device is not cleaned periodically, they can cause the wearer allergic reactions. In addition, if the openings are the sound level produced by the alarm can be greatly decreased. It is therefore essential to be able to regularly and easily clean the bottom, as well as the openings therein.

This phenomenon of formation of impurities and plugs in the bottom holes is accentuated with the devices security, the fact that these are intended, for definition, to be worn almost permanently by the user, which exposes them all the same to the environment pollutants.

In addition, the consequences of a possible malfunction of this type of safety device are obviously much more serious than with a wake-up device, since the good or the bad operation of a safety device may have direct consequences for safety or integrity physical and / or moral of its user, in case of aggression.

The natural answer to these types of problems is to provide an arrangement to prevent penetration of water and impurities inside the cavity of resonance, by complex filter systems or by the reduction of openings in the bottom.

However, these solutions are not satisfactory both in terms of cost and efficiency of the noise level produced.

An object of the present invention is to remedy these faults and bring a new solution to fouling of the resonant cavity of a security with acoustic alarm, portable and waterproof.

This goal is achieved thanks to the characteristics particular features of the claim 1.

Thanks to the features of the invention, the user can easily and regularly clean its safety device without the need for a tool. This allows him to clean his device for example in the shower or under a stream of water. So the level sound of the alarm device can be ensured by also cleaning openings due to the character removable from the bottom. In addition, the risk of injuring the bottom in removing it is thus avoided.

As the device remains complete even when the bottom is removed, the device is kept watertight. In effect, the bottom has no role in sealing which is guaranteed by the vibrator membrane.

Advantageously, the membrane is attached in a way allowing to further increase the sound level by the alarm.

• la figure 1 est une vue en coupe représentant de façon schématique le dispositif de sécurité à alarme selon l'invention;
• la figure 2 est une vue agrandie de la figure 1, représentant plus particulièrement la fixation d'une membrane portant un vibreur piézo-électrique et d'un fond sur un boítier du dispositif;
• la figure 3 est une vue de dessous du boítier seul représenté au figure 1 et 2; et
• la figure 4 est une vue de dessus du fond seul représenté aux figures 1 et 2.

An embodiment of the object of the invention will be described below, by way of example only, with reference to the appended drawings, in which:

• Figure 1 is a sectional view schematically showing the alarm security device according to the invention;
• Figure 2 is an enlarged view of Figure 1, showing more particularly the attachment of a membrane carrying a piezoelectric vibrator and a bottom on a housing of the device;
• Figure 3 is a bottom view of the housing alone shown in Figure 1 and 2; and
• FIG. 4 is a top view of the bottom alone shown in FIGS. 1 and 2.

Referring now to Figures 1 and 2, we will describe below an alarm security device acoustics according to the invention, identified here by the reference general 1.

The acoustic alarm safety device 1 is, in an advantageous non-limiting embodiment, consisting of a timepiece, in particular a wristwatch, comprising a case 2 comprising a middle 3 inside which is housed a circle casing 4 conventionally carrying a movement watchmaking 6, and a bezel 12 associated with a crystal 14 tightly mounted on the middle part 3. The functions main of this movement can be controlled by a rod 8 which can slide and rotate inside the case 2 and to which a crown 10 is subjected.

The watch movement 6 leads to a set of display means, here not referenced, intended to be move over an information dial.

This arrangement is sealed by the arrangement a seal 15 interposed between a region upper part 3 and bezel 12. Bezel 12 is mounted on notch on the middle 3.

In addition, the casing ring 4 carries a battery. supply 16 intended to supply a circuit electronic, not shown, likewise carried by the circle 4 and whose operation can be controlled by a push button 18 capable of actuating a contact electric supplying a voltage to said circuit electronic.

This electronic circuit, not shown, is linked electrically to a piezoelectric vibrator 20 which is fixedly fixed to a fixed membrane 22, as is will explain it below, in a region-tight manner bottom of case 2.

Thus, when the push button 18 is actuated by the user of safety device 1, the circuit electronic, not shown, delivered by contact electric or flange 24 a control signal causing the piezoelectric vibrator 20 to vibrate and its associated membrane 22, at the natural frequency of resonance. The electronic circuit can be arranged from so that push button 18 has to be operated two repeatedly to avoid triggering the vibrator 20 and therefore the audible alarm, which is too easy. However, the device 1 can also include two identical push buttons 18, located for example two hours and eight o'clock on the middle 3, which must be operated simultaneously to trigger the audible alarm.

Advantageously, the electronic circuit is arranged so that the stopping of the vibrator 20 is controlled by three consecutive actuations of the push button or push-buttons 18. Thus, stopping the audible alarm does not cannot be done easily by a possible aggressor.

The vibrating assembly formed by the piezoelectric vibrator 20 and the membrane 22 is secured to the middle part 3 of the case 2 via an attached ring 26, while the case 2 is closed at its base by a bottom drilled 28 which has the distinction of being removable and which can therefore be easily removed by the user.

For this purpose, we will now refer to Figure 2 which represents in more detail the assembly on the housing 2, on the one hand, from the bottom 28, and on the other hand, from the vibrating assembly formed by the vibrator 20 and the membrane 22.

The added ring 26 is of annular shape and has an axially opening in its center opening 30 which allows the movement in bending of the membrane 22 under the action of vibrator 20 to provide a sound due to its amplitude movement in a cavity resonant 32 formed by the bottom 28.

This added ring 26 has on its contour external a shoulder 34 which is shaped to come engage with notch on a cylindrical undercut 36 externally projecting from the middle part 3, from its base. In addition, the membrane 22 is housed between the ring 26 and the case 2 and it will be noted that it is pressed by its upper surface against the middle part 3, under the action of the added ring 26. Positioning shoulder 34 can also be adjusted to delimit an inner diameter which corresponds to the diameter of the membrane 22. This membrane 22 can thus be clipped or chased into the attached ring 26.

In addition, a seal 38 consisting of a elastic O-ring is housed in a groove 40, and is crushed inside this groove by being pressed against the upper surface of the membrane 22. So, this force pressing of the membrane 22 directly against the middle 3, provides excellent grip grip the membrane 22 which is made of a metallic material, for example brass or stainless steel. This tackle by force of the metal membrane 22 against the housing 2 also seals the housing 2 vis-à-vis the exterior thanks to the compression of the seal 38.

Advantageously, the metal membrane 22 is glued on the ring 26 which is removable, which allows, thanks to the notch mounting of the ring 26, to replace the battery 16, then replace the membrane 22 and the vibrator 20, during reassembly, on the correct side with respect to the flange 24 due to the subjugation of this membrane 22 to the ring 26. Thus, there is no risk of positioning at reverse of vibrator 20 with respect to electrical contact 24, which would of course have the effect of altering the operation of the safety device.

Therefore, the bonding of the membrane 22 on the ring 26 and the fixing of the ring 26 to the notch on the housing 2 ensure error-free positioning of the vibrator 20 with respect to its electrical contact 24, and ensures thus the functioning of the safety device in the event disassembly and reassembly.

We understand that a possible implementation the membrane 22, and in particular the vibrator 20, upside down on box 2, and without prior test by user, would have dramatic consequences for the user safety who, in the event of assault and after pressing button 18 would notice suddenly the non-functioning of his device security.

In addition, we note that the bottom 28 has wide openings 42 (two being here only represented) allowing the output of the sound created at the interior of the resonant cavity 32. This arrangement therefore provides a very high noise level.

So we understand that instead of preventing the penetration of water and any impurities to inside the resonant cavity, it facilitates otherwise this entry, but also the evacuation. In consideration, an advantageous provision has been made for mechanical connection between the housing 2 and the bottom 28, such that the bottom 28 can be very easily and regularly removed by the user, so that he can access the rear surface of the metal membrane 22 as well as inside the bottom 28 to ensure their cleaning.

We therefore planned a mechanical connection between the case 2 and the bottom 28 such that this bottom 28 can be removed without the need for a tool.

The free edge 28a of the bottom 28 further comprises two diametrically opposed beads or bulges 46 extending radially inwards from the bottom 28.

As seen in Figure 3, the housing 2 includes at its base, that is to say in its lower region, and directly above the staff 36 of the middle part 3, a lateral edge 44, including the first two regions 44a diametrically opposed each extend over a first arc of a circle α1, and has a first constant radius R1. These first two regions 44a, called engagement allow the establishment of the bottom 28, and in particular beads or bulges 46, on the housing 2, and especially on its edge 44.

Said edge 44 further comprises two second regions 44b of the same diametrically opposite arranged respectively in the extension of the first two regions 44a and adjacent thereto.

Each second region 44b extends over a second arc of circle α2 and has a second progressive radius R2.

In addition, the edge 44 has two third regions 44c also diametrically opposite, arranged respectively in the extension of the two second regions 44b and of contiguous to these.

Each third region 44c extends over a third arc of a circle α3 and has a third constant radius R3.

It is therefore understood that each intermediate region 44b constitutes a transition region between regions 44a and 44c and that the radius R2 gradually extends over the arc of circle α2 between the smallest radius R1 and the most large radius R3. This progressive radius R2 is between radius R1 and radius R3.

Relative to region 44a, region 44b forms a excess material which will cause the jamming of the bottom 28 by an external lateral action against bulges or bulges 46.

We will also specify that the edge 44 presents on 360 ° an undercut which helps to maintain force of the bottom 28 on the housing 2.

It will also be noted that the beads 46 are fitted by stamping on the end of the free edge 28a from the bottom 28. So, thanks to the transition region 44b, the beads 46 undergo a directed radial force outwards which block the bottom 28 against the housing 2. The bottom can therefore be removed manually from the housing 2 by rotation in opposite direction, then be put back easily by the user. Note that here there is no sealing between the bottom 28 and the housing 2, since this sealing is ensured between the ring 26-membrane assembly 22 and the middle part 3 of the case 2, via the seal 38. However, it is understood that a seal can be inserted between the back and the middle if this were desirable, for example in case the background was not perforated.

It will also be understood that the fixing of the membrane 22 on the housing 2 is of the built-in type, since the outer periphery of the membrane 22 is completely trapped between the added ring 26 and the middle part 3 of the case 2.

We will also specify that with a vibrator assembly 20-membrane 22 with a total thickness of 0.53 mm, the membrane has a thickness of 0.25 mm and the vibrator an additional thickness, it has been determined that the arrangement described provided a very high noise level raised by dimensioning the membrane 22 so that its diameter D, up to the inner edge of the ring reported 26, i.e. the diameter of its free surface was chosen between 29 and 31 mm. It was found that the better sound level was obtained with equal diameter at 30 mm; the diameter of the membrane being 35 mm, and that of the 25 mm vibrator in this example.

This result is surprising if we consider the theory relating to the nodal method of fixation. According to this theory, which is known to those skilled in the art, ends of the membrane should be free for obtain a maximum amplitude of the membrane, and therefore a maximum sound level. However, as it is better to have a device of small dimensions, this way fixing the membrane would involve high costs, because of complicated construction, and because of important dimensions which could further harm the aesthetics of the safety device.

We understand from what has just been described that the device according to the invention produces a very high noise level high, characteristic which can be ensured by the user himself thanks to the ease of cleaning of the device.

Although an embodiment of the invention has been illustrated, the invention is not limited to this specific construction, which is only given to title of nonlimiting example compared to the object of the invention.

Claims (10)

1. Acoustic alarm safety device comprising :

   a case (2),

   a thin membrane (22),

   a vibrating element (20) associated to said membrane (22) so as to make it vibrate,

   electric means for providing a control signal to said vibrating element and

   means (18) for actuating said electric means,

   characterized in that said device (1) further comprises

   a pierced back cover (28) attached to said case (2) and arranged so as to protect the case and so as to allow vibration of the vibrating element and membrane set (20, 22), said back cover being removably attached to said case in such a manner that the user of the device can manually remove said back cover while avoiding damaging the back cover because he needs no tool, and

   a fitted ring (26) to which said membrane (22) is attached, said ring (26) and said membrane (22) being secured to said case in such a manner that the ring-membrane set (26, 22) assures the waterproofness of said case (2).
2. Safety device according to claim 1, characterized in that said membrane (22) is flattened against said case (2) by the fitted ring (26).
3. Safety device according to claim 1 or 2, characterized in that said ring (26) is snap-fitted to said case (2).
4. Safety device according to any one of the preceding claims, characterized in that a watertight gasket (38) is located in a groove (40) arranged in said case (2), said gasket being crushed within said groove (40) and being flattened against the superior surface of said membrane (22).
5. Safety device according to any one of the preceding claims, characterized in that said fitted ring (26) is stuck to said membrane (22).
6. Safety device according to the preceding claim, characterized in that the diameter D of the free surface of said membrane (22) is chosen between 29 and 31 mm.
7. Safety device according to the preceding claim, characterized in that the diameter D of the free surface of said membrane (22) is 30 mm.
8. Timepiece characterized in that it comprises an acoustic alarm safety device according to any one of the preceding claims.
9. Safety device according to any of claims 1 to 7, being waterproof and comprising two elements forming respectively a case (2) and a back cover (28), characterized in that the first of said elements (2) has in its inferior region a lateral exterior edge (44) comprising :

   two first regions (44a) which are diametrically opposed and which each extend along a first circular arc (α1) having a first constant radius (R1), and

   two second regions (44b) which are diametrically opposed and which are each arranged respectively in the extension of said first regions (44a) such that they are adjacent said first regions, and which each extend along a second circular arc (α2) having a second progressive radius (R2), and

   two third regions (44c), which are diametrically opposed and which are each arranged respectively in the extension of said second regions (44b) such that they are adjacent said second regions, and which each extend along a third circular arc (α3) having a third constant radius (R3),

   and in that said second element (28) has a free edge (28a) comprising two bulges (46) which are diametrically opposed and which extend radially towards the interior of said back cover (28), such that said second regions (44b) which are formed of a material of increased thickness provoke the jamming of said back cover against said bulges (46).
10. Waterproof device according to claim 9, characterized in that said second progressive radius (R2) is comprised within the first radius (R1) and the third radius (R3).

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