MXPA97000915A - An alarm acoustic device, particularly for motorized vehicles - Google Patents

Abstract

The present invention relates to an acoustic alarm device, particularly for motor vehicles, comprising: a case in which at least one diaphragm is mounted to at least one excitation coil mounted in a fixed position in the case, so less a mobile ferromagnetic member, connected to the diaphragm and subjected to operation to the magnetic field generated by said coil, said mobile ferromagnetic member comprising an axial portion within which said coil is disposed, an acoustic outlet duct, and a normally closed switch device that includes two contact members that cooperate with each other and are adapted to move away after a deformation of the diaphragm, caused by the excitation of the associated winding, so as to interrupt the supply of current to said winding, characterized in that the switching device is disposed in said acoustic conduit I left

Description

AN ACOUSTIC DEVICE PE ALARMO, PARTICULARLY FOR MOTORIZED VEHICLES The present invention relates to acoustic alarm devices, particularly for motor vehicles, of the type defined in the introduction to claim 1. An acoustic alarm device of this type is des <: pl &e in UO93 / 01588 fn this acoustic alarm device lf) above, the switch is arranged on a bed defined between a diaphragm and the housing Fn US-n-4 540 q? 5 an electromagnet is described which included a diaphragm coupled to the mobile nucleus of an electromagnet, and neither a switch to interrupt the supply of current to the boiler cable, nor was the switch available in a single line. < ori da < ornpi ondi da entro e wi (ra < jrna e hotel «.iiueiit or K, The invention aims to provide an improved alarm device of the abovementioned type. This object is achieved according to the invention by means of an acoustic alarm device having the characteristics defined in claim 1. Additional features and advantages of the Will the invention be made clear from the following detailed description, presented with reference to the accompanying drawings, provided only? as a non-limiting example, in the Figure 1 is a perspective view of an acoustic alarm device according to the invention .. Figure 5? is a sectional view according to FIG. 11-E of FIG. 1. FIG. 3 is a partially sectioned side elevational view showing an enlarged scale of the alarm device shown in FIG. , and 0"FIG. 4 is a sectional view similar to that shown in FIG. 2, showing a variant or second embodiment of an acoustic alarm device according to the invention. Referring to the drawings, and specifically to the Figures 1 and 2, an acoustic alarm signal for motor vehicles according to the invention comprises a support box, generally indicated as 1. the ca is made o1 f 'syripi or a plastic material. shown by way of example, the ca (1 1) essentially comprises an upper portion 1 2 and a lower portion- or body 3, which are joined to each other, by * example, by * means of a hot sheet device, in a plane 4 (Figure 2) "The upper portion 2 of the box 1 is closed by a cover 5 while the lower portion 3 is closed at the bottom by a cover 5. Also said cover or closure members 5 and 6 are conveniently made of a plastic material and can be joined by ultrasonic welding (or other methods known per se) to the respective pt 2 and 3 of the box 1. Co or can be seen in Figure 2, in the axial central portion of the ca a 1 there is defined an essentially cylindrical passage 7 in which are mounted two mobile members 8 and 9 of ferromagnetic material, front axial entity and aligned with each other. The opposite ends of said members 8, 9 are connected to the central portions of two elastic membranes or diaphragms 10 and 11, made for example of a metal material, whose respective peripheral portions fit into the opposite end portions of the box 1, The axial end portions of members 8 and 9, facing each other or indicated 8a and 9 respectively, are configured substantially in the form of bells. FIG. 2 shows a stationary agile ferro member, configured substantially as a disk, which is fixed transversely in the passage 7 of the box 1 between the bell-shaped portions 8a and 9a of the mobile members 8 and 9. The periphery of said stationary ferromagnetic member 12 is separated from the end edges of said movable elements 8, 9 by respective air spaces 13 and 14.

As can be seen more clearly in Figure 3, two fixed cores 15, 16, made of ferromagnetic material, are connected to the central portions of the opposite faces of the stationary ferromagnetic member 12 .. Said fixed cores 15, 16 can be formed with separate elements, or integral with the member in the form 12. Around the fixed cores 15 and 16, respective reels 17 and 18 of an electrically insulating material are provided, which for example are overmolded on said cores 15 and 16. Said reels 17, 18 carry excitation coils. respective, indicated as 19 and 20. The opposite ends of the fixed cores 15 and 16 are separated from the associated mobile members 8 and 9 by air spaces 21 and 22, respectively (Figure 2). During the operation, when the coils 19 and 2 (1) are supplied with an excitation current, they can generate 1 magnetic luxuries that are found in the ferro-magnetic member in disc disk 12, in the associated fixed cores 15 and 16 and in the bell portions 8a, 9a of the mobile members R and 9. Under the effect of said magnetic flows, the mobile members 8 and 9 are attracted towards the disk-shaped ferromagnetic element 12, thus causing a elastic deformation of the diaphragms 10 and 11, respectively, associated therewith In the case 1, between the diaphragm 10 and 11 a variable volume chamber is defined, which is in communication with an acoustic exit conduit 23 defined in FIG. box 1, through an essentially radial passage 27. Said acoustic conduit develops substantially like a spiral around the central passage 7 and ends up forming a flared exit radiation section 29, configured as a horn. the operation, when the energizing bobbins 19 and 20 are supplied with a current, the members (mobile erromagneti eos 8 and 9 move one towards the o ro ba or the effect of the generated magnetic field, causing 1,! an elastic deformation of the diaphragms 10 and 11 and a reduction of the volume of the chamber defined above of volume v pab Le "., e mounts a switch device, generally indicated as 34 in Figure 2, in step 27 that The variable volume chamber is placed in communication with the output acoustic conduit 28. In the illustrated embodiment said switch device 34 comprises two configured metal sheets 37 and 38 having an end which is fixed at 39 to the box 1. opposite end portions of the blades 37 and 38 bear, in mutually frontal relation, respective contact members 41 and 42. Beyond said contact members, the torminate portions of said blade ends 37 and 38 have respective, bent appendices descending and ascending, respectively, indicated as 43 and 44. Said bent indexes 43, 4 extend towards the central cylindrical passage 7 of the box l of the alarm device, specifically between the end edges of the bell-shaped portions 8a, 9a of the movable members 8, 9. The terminal bent appendices 43 and 44 of the sheets 37 and 38 are graduated in a direction that is orthogonal to the plane of Figure 2 and at rest are disposed adjacent to, or in contact with, the end edges of the bell-shaped portions 9a and 8a of the movable members 9 and 8. The disk-shaped ferromagnetic member 12 is conveniently provided with a radial groove indicated as 12a in Figure 3, in correspondence with the ends of the bent appendices 43, 44 of the blades 37, 38 of the switch 34 ,. At rest, mainly in the non-excited condition of the coils 19 and 20, the contacts 41 and 42 of the switch 44 are in contact with each other. In this way, the switch 34 is not badly erroneous, to allow the supply of said fluxes 19, 20 by activation of the dip? S? Ti vo of a 1 pn .. When the alarm device is activated, the excitation of the bulges 19, 20 causes a displacement of mutual approximation of the mobile members 8 and 9., that with the end edges of the respective bell shaped portions 8a, 9a adjust the bent end appendices 44, 43, causing separation of the contact members 41 and 42. In this way the switch 34 is opened and interrupts the flow of current to the 19 and 20. The mobile ferroinagnetic members 8 and 9 then return to the rest position under the effect of the return action exerted by the diaphragms 10 and 11 .. Fl displacement of the limbs. 8 and 9 one outside the other then allows the switch 34 to close and a current to be supplied once again to the bobbins 19 and 20. The operation continues in this way until the device is activated, mainly until it has been copied to a voltage source (not shown). During the operation, the vibration of the diaphragms and 11 causes the generation of a sound radiation which reaches the acoustic outlet conduit 28 through the radial passage 27 from the variable volume chamber in which the mobile members 8 and 9 are mounted. Due to the presence of two contracted vibration assemblies, with the acoustic alarm device described Subsequently, it is practically avoided that the box 1 can transmit reactions or vibrations to the body of the motor vehicle in which the alarm device is installed. Possible arcs generated between the contacts 41, 42 are "blown" under the action of the air set in vibration after the oscillation of the elastic diaphragms 10 and 11. In FIG. 4, a variant or additional embodiment of an acoustic device is illustrated. alarm according to the invention.

In said Figure, the same reference numbers have been attributed once again to the parts and elements already described in the previous one. The variant of conformity to Figure 4 differs from the previously described embodiment in which inside the booms 19, 20 there is no longer a fixed ferromagnetic core, but rather cylindrical respective appendages 8b, 9b of the mobile ferromagnetic members 8 and 9. Among said mobile terromagnet members, LL can be) * Is a stationary ferromagnet member provided with, for example, the shape of a disk as for the L2 imembro of the Figure? , for the circulation of the magnetic fluxes generated by Los bobi najes. However, as an alternative, such a ferromagnetic member can be avoided, and in such a case the magnetic fluxes generated by the coils circulate completely in the two mobile ferromagnet members and the air spaces defined in FIG. they. Furthermore, in such a case the two excitation bobbins can be replaced by only one bob. Naturally, the principles of the invention remain the same; the forms and the embodiments and details of construction may be varied widely with respect to those described and illustrated solely by way of non-limiting example, without thereby departing from the scope of the present invention as defined in the appended claims. In particular, although the embodiments described above comprise two assemblies that vibrate in phase opposition, the invention can also be applied successfully to acust alarm devices provided with a single vibration assembly, and thus with a single diaphragm the . The invention is also not intended to be limited to alarm devices that comprise an electromechanical switch, but can also be implemented in acoustic alarm devices in which the interruption of the excitation current is controlled by means of electronic devices. static

Claims (13)

THE NOVELTY OF THE INVENTION CLAIMS

1. An acoustic alarm device, particularly for motorized vehicles, comprising a box (1) in which at least one diaphragm (10, 11) is mounted at least one excitation booster (19, 20). ) mounted in a fi xed position in the box (1), at least one mobile ferromagnetic member (8, 9), connected to the diaphragm (10, 11) and? operating in the magnetic field generated by said coil e fl , twenty); said ferro-magnetic member LCO rnóvi 1 (8,9) comprises an axial end portion (8a, 9a), inside which said coil (19, 20) is disposed; an acoustic outlet duct (27-29), and a normally closed switch device (34) including two contact members (41-42) cooperating with each other and adapted to move away after a deformation of the diaphragm (10, 11). ) caused by the excitation of the associated bulge (19, 20), so as to interrupt the supply of current to said coil (19, 20); characterized in that the switching device (34) is arranged in said output acoustic conduit (27-29).

2. An alarm device according to claim 1 characterized in that said axial end portion (8a, 9a) of the mobile ferromagnetic member (8, 9) has an end edge that is separated by an air space (13, 14) from the peripheral portion of a stationary ferromagnetic member (12), connected to the winding e (19, 20) and mounted in a position f ja on the ca (1) adjacent to the end portion of the coil e ( 19, 20) opposite said ferro-magnetic rod member (8, 9).

3. An alarm device according to claim 2, characterized in that the stationary ferromagnetic member (12) is substantially configured as a disk, and is disposed adjacently in at least one fixed ferromagnetic core (15, 16) that is extends within a coil (19, 20) up to near the mobile agile ferrous member (8, 9).

4. An alarm device according to claim 3, characterized in that the stationary ferromagnetic member (12) is integral with at least one fixed core of the aforementioned (15, 16).

5. A device "alarm in accordance with claim 1 characterized in that at least one of the The aforementioned movable ferromagnetic bodies (8, 9) comprise a central appendage (8b, 9b) extending within said axial end portion (8a, 9a) thereof and within the associated bobbin (19, 20). ).

6. An alarm device according to claim 1 characterized in that said switch device (34) comprises two blades (37, 38) carrying respective contact members (41 42) that are in contact with each other at rest; at least one blade (37, 38) is adapted to cooperate with at least one moving member of the aforementioned (8, 9); when in operation, said movable member (8, 9) moves after an excitation of the associated coil (19, 20), so that the contact member (41, 42) carried by a leaf (37, 38) is 7.- An alarm device according to any of the present claims, characterized in that it comprises a first and a second diaphragm (10, 11).

They are arranged in front relation and at a mutual distance in the ca (1), with the respective peripheral portions adjusted in the box (1), said diaphragms (10, 11) are elastically deformable and are adapted to define between them a variable volume chamber (7) in communication with the inlet (27) of an acoustic outlet duct (27-29), a first and a second mobile agrical ferro member (8, 9) that are axially in front of each other and separated by a space .? air (13, 14) and which at opposite ends thereof are connected to the first and second diaphragms (10, 11), respectively; at least one winding of the aforementioned ones (19, 20) is coupled in operation to said mobile ferromagnetic members (8, 9) in such a way that the intermittent excitation of said coil ae (19, 20) causes corre sponding movements. in opposition to said mobile members (8, 9) and the counterphase vibration of the associated diaphragms (10, Ll).

8. - An alarm device according to claim 6 and claim 7 characterized in that said leaves (37, 38) extend in said chamber (7) and are adapted to cooperate each with one of the respective mobile ferro-magnetic members mentioned (8). , 9) so that when said movable members (8, 9) are in operation and move toward each other, the contact members (41, 42) carried by said leaves (37, 38) move one out of the other.

9. An alarm device in accordance with the rei indication 8 characterized in that said leaves (37, 38) are arranged in front relation in the direction of movement of said mobile ferronagnet members (8, 9) and are Each one is provided with a respective oxtim appendix (43, 44) which is bent towards the other leaf (38, 97) and has an end portion facing an adjustment orifice (Oa). , 9a) of an associated ferro-magical member (8, 10 -.

10 - An alarm device according to claim 1 and 7 characterized in that said mobile ferromagnetic members (8, 9) have respective bell-shaped portions (8a, 9a), facing each other, surrounding at least one coiling of the aforementioned (19, 20); the stationary ferromagnetic member (12) extends radially in the air space (13, 14) defined between the bell-shaped portions (8a, 9a) of said mobile ferro-agile members (8, 9).

11. An alarm device according to claim 10, characterized in that said stationary ferromagnetic member (12) is embodied as a disk and is disposed between two fixed ferromagnetic nodes (15, 15). They have a reduced diameter, which are placed coa i the rne between each other and with them.

12. An alarm device according to claim 11, characterized in that it includes two excitation coils (19, 20) each arranged around a respective core (15, 16).

13. An alarm device according to claim 10 or 11 and claim 8, characterized in that said stationary ferromagnetic member (12) is provided with a peripheral radial groove (12a) and because the free ends of the blades (37, 38) of the device i terruptor (349 , extend in said groove (12a).