Classifications

• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
  • G10K9/00—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers
  • G10K9/02—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers driven by gas; e.g. suction operated
  • G10K9/04—Devices in which sound is produced by vibrating a diaphragm or analogous element, e.g. fog horns, vehicle hooters or buzzers driven by gas; e.g. suction operated by compressed gases, e.g. compressed air

Definitions

• the present invention relates to an electropneumatic horn particularly adapted to equip two- and four-wheeled motor vehicles.
• the electropneumatic horns of the prior art comprise a generator of sound waves including one or more acoustic units, connected to an electric compressor by ducts for air passage to generate a mono, bi o tri tonal tuned sound according to the number of acoustic units.
• the acoustic units consist of a straight exponential duct of a length proportional to the frequency to be reproduced, inserted in an acoustic chamber in which a membrane free to move with a reciprocating motion is arranged.
• the straight duct comprises a first stretch with generally constant section, provided with an inlet mouth for the sound signal generated by the oscillating membrane and a second stretch having a section varying with a generally conic exponential law ending with an outlet mouth for the amplified sound signal.
• the membrane is properly stretched in a calibration phase by deformation against said membrane of a metal member referred to as bottom and applied to the shape of chamber body, in such a way to generate a sound with predetermined acoustic pressure.
• the acoustic units are two and the corresponding ducts are volute wound and juxtaposed to limit the overall dimensions of the horn.
• said acoustic horns and more particularly those with a straight acoustic units equip motor vehicles and are generally installed in the engine compartments.
• Acoustic horns with different features are available on the market, mainly classified according to the number of acoustic units, generally one to maximum three for the tuned sound, and according to the frequency that each unit should reproduce.
• the compressor and the acoustic units are individually anchored to opposite supports through corresponding fastening members.
• a first drawback of such horns consists of the assembling complexity in the installation phase because bracketing of two or more components corresponding to the compressor and the acoustic units is required.
• Another drawback consists in that the connection between each acoustic unit and the compressor is difficult and time consuming and does not warrant when improperly effected, instantaneousness and contemporaneousness of sound of the acoustic units.
• a first object of the invention is to provide an electropneumatic horn of a more compact structure relative to the electropneumatic horns of the prior art.
• Another object of the invention is to provide an electropneumatic horn reducing the assembling complexity relative to equivalent electropneumatic horns of the prior art.
• a further object of the invention is to provide an electropneumatic horn allowing quick disassemble operations in case of mainteinance work. It is then another object of the invention to provide an acoustic horn that in view of its features may be a valid alternative but with greater acoustic power to the electromagnetic horns.
• a further object of the invention is to provide an acoustic horn having better features of sound instantaneousness and contemporaneousness relative to known electropneumatic horns, said the features being comparable to those of the electromagnetic horns.
• a last but not least object of the invention is to provide an electropneumatic horn that may be a valid alternative to the electromagnetic horns in view of its greater reliability, more particularly as to resistance to an uninterrupted sound emission and reliability in the sense of product useful life.
• an electropneumatic horn that according to the wording of the main claim comprises:
• a sound wave generator comprising at least an acoustic chamber provided with at least an inlet for entry of pressurised air in which there is an elastic membrane for sound generation and at least a volute wound acoustic duct defined between an outer shell and a diaphragm, said acoustic duct communicating with said acoustic chamber and being adapted to propagate to the outside the sound generated by said membrane;
• - air channelling means adapted to put said outlet of the compressor unit in communication with said inlet of the acoustic chamber; and it is characterized in that said at least a compressor unit and said sound wave generator are mechanically connected in a removable way by fitting slidingly a collar.
• the sound wave generator comprises two acoustic ducts defined between two opposite shells between which a diaphragm is interposed, a collar portion being made integral with each shell. Said collar is also provided with a labyrinth suction duct putting the compressor suction inlet in communication with the outside.
• the channelling means comprise an injector being part of the compressor and arranged after the outlet and coupled to a duct made in the diaphragm by snapping.
• the sound wave generator comprises a single acoustic duct defined between a shell and a diaphragm while a portion of the collar is made integral with the shell and another portion with the diaphragm.
• the acoustic horn comprises fastening means consisting of a single projecting element made in the compressor body for connection to the support structure.
• the acoustic horn of the invention may be supplied as a kit comprising a compressor unit and a sound wave generator that are coupled through the collar and therefore may be used to equip two and four wheeled vehicles with a simple assembling operation of the two main parts by snapping, namely generator and compressor, by the user.
• the compact structure of the acoustic horn minimizes the paths of the compressed air flows from the compressor to the acoustic chambers thus increasing the performance as to sound instantaneousness and contemporaneousness when more acoustic ducts are provided. Also advantageously the compact structure of the acoustic horn allows more favourable installations for sound propagation from the vehicles, still respecting the minimum values for the type approval, more particularly in comparison with the electromagnetic horn of substantially less acoustic power.
• - Fig.1 is partially sectioned side view of the acoustic horn of the invention
• - Fig.2 is an enlarged view of a detail of the channelling means of fig.1 ;
• Fig.3 is a sectional view of the detail of fig. 2 taken along line ll-ll;
• Fig. 4 is a sectional view of the acoustic horn of fig.1 taken along line l-l;
• - Fig.5 is a side view of the diaphragm of the acoustic horn of fig.1 ;
• - Fig.9 is f a sectional side view taken along line VIII-VIII of fig.8;
• - Fig.10 is a sectional view taken along line l-l of a constructional variation of fig.1 ;
• - Fig.11 is a sectional view taken along line l-l of another constructional variation of fig.1 ;
• - Fig.12 is a side view of the diaphragm of fig.11 ;
• - Fig.13 is a top view of the diaphragm of fig.12; and - Fig.14 is a side view of the diaphragm of fig.12;
• Fig. 15 is a sectional view taken along line l-l of a further constructional variation of fig. 1 ;
• - Fig. 16 is a lateral view of the diaphragm of fig. 15;
• Fig.1 The acoustic horn of the invention is shown in Fig.1 where it is generally indicated with numeral 1.
• the horn comprises a compressor unit 2, a sound wave generator 3 and air channelling means 4 adapted to put the compressor 2 in communication with the sound wave generator 3.
• the compressor unit 2 is provided with a suction inlet 5 from which air from outside is sucked, and an outlet 6 for the compressed air.
• a suction inlet 5 from which air from outside is sucked
• an outlet 6 for the compressed air.
• the sound wave generator 3 comprises two acoustic chambers indicated with numerals 7 and 8 in fig.4 respectively, each chamber being provided with an opening 9, 10, for introduction of pressurised air.
• a volute wound acoustic duct 13, 14 is associated to each acoustic chamber 7, 8 and defined between an outer shell 15, 16 and a diaphragm 17 common to both acoustic duct 13, 14 and interposed between said shells 15, 16.
• Each acoustic duct 13, 14 has a first stretch with generally constant section 19, 20 provided with an inlet 21 , 22 communicating with the acoustic chamber 7, 8.
• the first constant section stretch 19, 20 of ⁇ the acoustic duct 13, 14 is connected to a second stretch 23, 24 at the point indicated with numerals 25, 26 in fig. 1 and has a section varying with a generally conic exponential law ending with an outlet 27, 28 for sound propagation to the outside.
• each acoustic duct 13, 14 is consistent with the frequency to be obtained and in this case to obtain a tuned bi- tonal sound.
• the channelling means 4 put the outlet 6 of the compressor 2 in communication with openings 9, 10 for introduction of pressurized air into the acoustic chambers 7, 8.
• Said channelling means 4 comprise:
• each intermediate chamber 31 , 32 defines the opening 9, 10 of connection with the corresponding acoustic chamber 7, 8;
• the compressor unit 2 and the sound wave generator unit 3 are mechanically connected through a collar generally indicated with numeral 34.
• Said flange 34 as better shown in fig. 4, is made as an integral extension of the two shells 15, 16 like two portions 34a and 34b having a generally semicircular shape adapted to receive the body of compressor 2 that has generally a cylindrical shape. Obviously the shape of the two portions 34a and 34b may be different in other embodiments and fit to the shape of the body of compressor 2.
• On collar 34, and more particularly on the potion 34b on the side where the suction inlet 5 is arranged there is a suction duct 35, having a labyrinth configuration and putting the suction inlet 5 in communication with the outside.
• each acoustic chamber 7, 8 is defined by a shaped body 7a, 8a applied to the corresponding outer shell 15, 16.
• the elastic membrane 11 , 12 is constrained to the shaped body 7a, 8a through a metal bottom 38, 39 superimposed externally and fixed by flanging to the shaped body 7a, 8a in order to tension the membrane during the calibration phase as a function of the level of sound pressure to be propagated.
• a cap 40, 41 coupled to the shaped body 7a, 8a by mechanical fit is arranged as a cover and protection of bottom 38, 39.
• fastening means 42 consisting of a shaped projecting member adapted to receive screw elements for connection of the acoustic horn 1 to a support structure S.
• the diaphragm 17 is provided with hooking snap means 17a adapted to constrain said diaphragm 17 to the compressor unit 2 and to warrant the pneumatic seal when the compressor 2 and the sound wave generator 3 are mutually joined by collar 34 and the injector 29 is fully inserted into the duct 33 made on said diaphragm 17.
• the acoustic horn 1 may be advantageously supplied as a kit with the parts consisting of the compressor unit 2 and the sound wave generator 3 divided, that can be easily assembled by the user before installation by snapping.
• the assembling operation is carried out by inserting the injector 29 of the compressor unit 2 into the duct 33 of the diaphragm 17 for such a length as to allow the snap means 17a to constrain the diaphragm 17 to the body of the compressor unit 2 warranting the pneumatic seal as well.
• the collar 34 through its portions 34a and 34b is coupled by mechanical fit with the outer surface of the compressor unit 2.
• the labyrinth suction duct 35 allows protection of the air suction inlet 5 from possible foreign matter and water splash that instead may enter directly inside the compressor unit 2.
• a first embodiment of the acoustic horn is shown in fig.10 and is generally indicated with numeral 100.
• each intermediate chamber 131 , 132 will obviously have a different shape relative to the first embodiment of fig.4.
• FIG.11 Another embodiment of the invention is shown in fig.11 and is generally indicated with numeral 200.
• This modification relates more particularly to a mono-tonal acoustic horn obviously having a single acoustic duct 213 as a single sound wave should be propagated.
• connection collar 234 is made in two parts, a first part as extension integral with the outer shell 215 and a second part integral with the diaphragm 217 as shown in detail in figures 12 and 13.
• a further embodiment of the invention is shown in fig. 15 and is indicated as a whole with 300.
• a bi-tonal acoustic horn provided with two acoustic ducts 313, 314 which, as in the realization of fig. 1 , are defined between the two opposed shells 315, 316 and the diaphragm 317.
• the collar 334 is made integral with the diaphragm 317, said diaphragm also presents the walls of the acoustic ducts 313, 314, as it can be seen in figs. 16 and 18.
• the two shells 315 and 316 are preferably, but not necessarily, connected to the diaphragm 317 through glueing or ultrasound welding.
• the bi-tonal horns of the invention can be associated to sound modulation systems, which are not shown in the figures, allowing sounds production with different melodies.
• a first of such known techniques relates to the use of an electrovalve connected to an electronic control unit that determines the position of the electrovalve in order to convey and to modulate the air flow in the ducts.
• the distribution of the air flow towards the acoustic ducts is obtained through a gear mechanic system which controls the valve according to the desired flow, said gear mechanic system is connected to the driving shaft associated to the compressor unit by reducing means.
• the acoustic horn of the invention attains the intended objects and advantages.
• Other constructional modifications may be made to the acoustic horn in the execution phase.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Multimedia (AREA)
• Compressor (AREA)
• Reciprocating Pumps (AREA)
• Looms (AREA)
• Surgical Instruments (AREA)
• Arrangements For Transmission Of Measured Signals (AREA)
• Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
• Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)
• Piezo-Electric Transducers For Audible Bands (AREA)
• Fire-Detection Mechanisms (AREA)
• Burglar Alarm Systems (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (4)

Families Citing this family (14)

Citations (3)

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• 2001
  • 2001-12-28 IT IT2001VI000270A patent/ITVI20010270A1/it unknown
• 2002
  • 2002-08-09 CN CNB028261518A patent/CN100361196C/zh not_active Expired - Fee Related
  • 2002-08-09 AU AU2002336960A patent/AU2002336960B2/en not_active Ceased
  • 2002-08-09 JP JP2003556984A patent/JP3954569B2/ja not_active Expired - Fee Related
  • 2002-08-09 EP EP02772137A patent/EP1459293B8/en not_active Expired - Lifetime
  • 2002-08-09 AT AT02772137T patent/ATE394772T1/de not_active IP Right Cessation
  • 2002-08-09 US US10/489,825 patent/US7038576B2/en not_active Expired - Fee Related
  • 2002-08-09 DE DE60226492T patent/DE60226492D1/de not_active Expired - Lifetime
  • 2002-08-09 ES ES02772137T patent/ES2305297T3/es not_active Expired - Lifetime
  • 2002-08-09 WO PCT/EP2002/008945 patent/WO2003056545A1/en not_active Ceased
  • 2002-08-09 RU RU2004123096/28A patent/RU2269828C2/ru not_active IP Right Cessation

Patent Citations (3)

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