Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
  • H04R1/028—Casings; Cabinets ; Supports therefor; Mountings therein associated with devices performing functions other than acoustics, e.g. electric candles
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07F—COIN-FREED OR LIKE APPARATUS
  • G07F9/00—Details other than those peculiar to special kinds or types of apparatus
  • G07F9/02—Devices for alarm or indication, e.g. when empty; Advertising arrangements in coin-freed apparatus
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
  • H04R1/021—Casings; Cabinets ; Supports therefor; Mountings therein incorporating only one transducer
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R1/00—Details of transducers, loudspeakers or microphones
  • H04R1/02—Casings; Cabinets ; Supports therefor; Mountings therein
  • H04R1/025—Arrangements for fixing loudspeaker transducers, e.g. in a box, furniture
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R3/00—Circuits for transducers, loudspeakers or microphones
  • H04R3/04—Circuits for transducers, loudspeakers or microphones for correcting frequency response
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R7/00—Diaphragms for electromechanical transducers; Cones
  • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
  • H04R7/04—Plane diaphragms
  • H04R7/045—Plane diaphragms using the distributed mode principle, i.e. whereby the acoustic radiation is emanated from uniformly distributed free bending wave vibration induced in a stiff panel and not from pistonic motion
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R17/00—Piezoelectric transducers; Electrostrictive transducers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R5/00—Stereophonic arrangements
  • H04R5/02—Spatial or constructional arrangements of loudspeakers

Definitions

• the invention relates to vending machines.
• a panel-form loudspeaker comprising:- a resonant multi-mode radiator element being a unitary sandwich panel formed of two skins of material with a spacing core of transverse cellular construction, wherein the panel is such as to have ratio of bending stiffness (B) , in all orientations, to the cube power of panel mass per unit surface area ( ⁇ ) of at least 10; a mounting means which supports the panel or attaches to it a supporting body, in a free undamped manner; and an electro-mechanical drive means coupled to the panel which serves to excite a multi-modal resonance in the radiator panel in response to an electrical input within a working frequency band for the loudspeaker.
• B bending stiffness
• ⁇ cube power of panel mass per unit surface area
• Embodiments of the present invention use members of nature, structure and configuration achievable generally and/or specifically by implementing teachings of our co ⁇ pending PCT application no. ⁇ Our case P.5711) of even date herewith.
• Such members thus have capability to sustain and propagate input vibrational energy by bending waves in operative area(s) extending transversely of thickness often but not necessarily to edges of the member(s); are configured with or without anisotropy of bending stiffness to have resonant mode vibration components distributed over said area(s) beneficially for acoustic coupling with ambient air; and have predetermined preferential locations or sites within said area for transducer means, particularly operationally active or moving part(s) thereof effective in relation to acoustic vibrational activity in said area(s) and signals, usually electrical, corresponding to acoustic content of such vibrational activity.
• This invention is particularly concerned with vending machines incorporating active acoustic devices e.g. in the form of loudspeakers for the purpose of providing information concerning the manner of operation of the machine or its contents.
• the term 'vending machine' is intended to encompass not only food and drink and the like dispensers but also ticket dispensers, automated Bank telling machines, cash dispensers, and the like.
• distributed mode radiators are intended to be characterised as in the above PCT application and/or otherwise as specifically provided herein.
• the invention is a vending machine of the kind comprising a store of articles or product to be dispensed, user operated means for selecting the article or product to be dispensed, means, e.g. a coin freed mechanism authorising dispensing, and a dispensing outlet, characterised by a loudspeaker comprising a distributed mode acoustic radiator and a transducer mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.
• the vending machine may comprise a visual display panel formed by the radiator.
• the radiator may comprise a stiff lightweight panel having a cellular core sandwiched between a pair of skins, the panel being surrounded by a frame and mounted in the frame by means of a resilient suspension.
• the vending machine may comprise a body and the frame may be attached to or formed by the body.
• the vending machine may comprise a second transducer coupled to the radiator to produce a signal in response to resonance of the radiator due to incident acoustic energy.
• a further transducer may be provided on the radiator to produce a signal in response to resonance of the radiator to due to incident acoustic energy, and means may be provided for comparing the signal generated by the said further transducer with that of those generated by the said second transducer(s) .
• the comparison means may comprise a signal receiver and conditioner and signal output means.
• Figure 2a_ is a partial section on the line A-A of Figure 1;
• Figure 2b is an enlarged cross-section through a distributed mode radiator of the kind shown in Figure 2a_ and showing two alternative constructions;
• Figure 3 is a perspective diagram of an embodiment of vending machine according to the present invention.
• Figure 4 is a partial cross-sectional view of a detail of the vending machine of Figure 3;
• Figure 5 is a perspective diagram of a modified form of vending machine
• Figure 6 illustrates one form of transducer.
• the transducer (9) is driven by a signal amplifier
• Figures 2a . and 2b are partial typical cross-sections through the loudspeaker (81) of Figure 1.
• Figure 2a. shows that the frame (1), surround (3) and panel (2) are connected together by respective adhesive-bonded joints (20) .
• Suitable materials for the frame include lightweight framing, e.g. picture framing of extruded metal e.g. aluminium alloy or plastics.
• Suitable surround materials include resilient materials such as foam rubber and foam plastics.
• Suitable adhesives for the joints (20) include epoxy, acrylic and cyano-acrylate etc. adhesives.
• Figure 2b illustrates, to an enlarged scale, that the panel (2) is a rigid lightweight panel having a core (22) e.g. of a rigid plastics foam (97) e.g. cross linked polyvinylchloride or a cellular matrix (98) i.e. a honeycomb matrix of metal foil, plastics or the like, with the cells extending transversely to the plane of the panel, and enclosed by opposed skins (21) e.g. of paper, card, plastics or metal foil or sheet.
• the skins are of plastics, they may be reinforced with fibres e.g. of carbon, glass, Kevlar (RTM) or the like in a manner known per se to increase their modulus.
• RTM Kevlar
• Envisaged skin layer materials and reinforcements thus include carbon, glass, Kevlar (RTM), Nomex (RTM) i.e. aramid etc. fibres in various lays and weaves, as well as paper, bonded paper laminates, melamine, and various synthetic plastics films of high modulus, such as Mylar (RTM), Kaptan (RTM), polycarbonate, phenolic, polyester or related plastics, and fibre reinforced plastics, etc. and metal sheet or foil.
• Investigation of the Vectra grade of liquid crystal polymer thermoplastics shows that they may be useful for the injection moulding of ultra thin skins or shells of smaller size, say up to around 30cm diameter.
• This material self forms an orientated crystal structure in the direction of injection, a preferred orientation for the good propagation of treble energy from the driving point to the panel perimeter.
• Additional such moulding for this and other thermoplastics allows for the mould tooling to carry location and registration features such as grooves or rings for the accurate location of transducer parts e.g. the motor coil, and the magnet suspension.
• Additional with some weaker core materials it is calculated that it would be advantageous to increase the skin thickness locally e.g. in an area or annulus up to 150% of the transducer diameter, to reinforce that area and beneficially couple vibration energy into the panel. High frequency response will be improved with the softer foam materials by this means.
• Envisaged core layer materials include fabricated honeycombs or corrugations of aluminium alloy sheet or foil, or Kevlar (RTM), Nomex (RTM), plain or bonded papers, and various synthetic plastics films, as well as expanded or foamed plastics or pulp materials, even aerogel metals if of suitably low density.
• Some suitable core layer materials effectively exhibit usable self-skinning in their manufacture and/or otherwise have enough inherent stiffness for use without lamination between skin layers.
• a high performance cellular core material is known under the trade name 'Rohacell' which may be suitable as a radiator panel and which is without skins. In practical terms, the aim is for an overall lightness and stiffness suited to a particular purpose, specifically including optimising contributions from core and skin layers and transitions between them.
• piezo and electro dynamic transducers have negligible electromagnetic radiation or stray magnet fields.
• Conventional speakers have a large magnetic field, up to 1 metre distant unless specific compensation counter measures are taken.
• the suspension (3) may damp the edges of the panel (2) to prevent excessive edge movement of the panel. Additionally or alternatively, further damping may be applied, e.g. as patches, bonded to the panel in selected positions to damp excessive movement to distribute resonance equally over the panel.
• the patches may be of bitumen-based material, as commonly used in conventional loudspeaker enclosures or may be of a resilient or rigid polymeric sheet material. Some materials, notably paper and card, and some cores may be self-damping. Where desired, the damping may be increased in the construction of the panels by employing resiliently setting, rather than rigid setting adhesives.
• Effective said selective damping includes specific application to the panel including its sheet material of means permanently associated therewith. Edges and corners can be particularly significant for dominant and less dispersed low frequency vibration modes of panels hereof. Edge-wise fixing of damping means can usefully lead to a panel with its said sheet material fully framed, though their corners can often be relatively free, say for desired extension to lower frequency operation. Attachment can be by adhesive or self-adhesive materials. Other forms of useful damping, particularly in terms of more subtle effects and/or mid- and higher frequencies can be by way of suitable mass or masses affixed to the sheet material at predetermined effective medial localised positions of said area.
• An acoustic panel as described above is bi ⁇ directional. The sound energy from the back is not strongly phase related to that from the front. Consequently there is the benefit of overall summation of acoustic power in the room, sound energy of uniform frequency distribution, reduced reflective and standing wave effects and with the advantage of superior reproduction of the natural space and ambience in the reproduced sound recordings.
• FIG 3 illustrates a vending machine (108), e.g. a drinks dispenser incorporating a loudspeaker (81) whereby the loudspeaker forms part of the front face (109) of the vending machine.
• the loudspeaker (81) is arranged to provide audio information as to the dispensable contents of the machine and/or the manner it is to be operated.
• the front (109) of the machine carries the normal coin or the like freed mechanism (143), product selector panel (137) and dispenser outlet (142).
• the loudspeaker (81) comprises a rectangular lightweight rigid distributed mode radiator panel (2) comprising a cellular core (22) having skin layers (21) on both faces, the panel being supported around its periphery on a resilient suspension (3), e.g. of foam rubber.
• the suspension is mounted in a rectangular frame (1) mounted in the front face (109) of the machine (108).
• Visual information e.g. in the form of graphics and text, may be applied to the panel (2) as desired.
• the panel (2) carries a transducer (9), e.g. of the kind described with reference to our co-pending International application Nos. (our files P.5683/4/5) of even date herewith, whereby the panel can be vibrated to cause it to resonate to produce an acoustic output.
• the machine will incorporate the required signal generator to produce the necessary messages and amplifier means (not shown) for driving the transducer (9) .
• the device can be made to be proactive by arranging that the distributed mode panel (2) is capable of use both as a loudspeaker and as a sound receiver or microphone, as shown in Figure 5.
• the panel is driven to resonate and produce an acoustic output by a transducer (9) of the kind described in our co-pending International application No. of even date herewith, (our files P.5683/4/5), which in turn is connected to and driven by an amplifier (10) .
• the panel also carries a pair of vibration transducers (63) which may be piezo-electric transducer of the kind shown in Figure 6 which are coupled in parallel to drive a signal receiver and conditioner (65) connected to an output (66).
• Another vibration transducer (63) on the panel (2), e.g. of the kind shown in Figure 6 is coupled to drive a filter/correlator the output from which is fed to the signal receiver and conditioner (65), to provide signal correction and/or noise cancellation.
• FIG. 6 shows a transducer (9) for a distributed mode panel (2) in the form of a crystalline disc-like piezo bender (27) mounted on a disc (118), e.g. of brass, which is bonded to a face of the panel (2), e.g. by an adhesive bond (20) .
• a transducer (9) for a distributed mode panel (2) in the form of a crystalline disc-like piezo bender (27) mounted on a disc (118), e.g. of brass, which is bonded to a face of the panel (2), e.g. by an adhesive bond (20) .
• an acoustic signal applied to the transducer (9) via leads (28) will cause the piezo disc (27) to bend and thus locally resiliently deform the panel (2) to launch bending waves into the panel.
• the device is configured such that verbal instructions can be given to the vending machine.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• General Physics & Mathematics (AREA)
• Multimedia (AREA)
• Control Of Vending Devices And Auxiliary Devices For Vending Devices (AREA)
• Vending Machines For Individual Products (AREA)
• Confectionery (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Formation And Processing Of Food Products (AREA)
• Soil Working Implements (AREA)
• Eye Examination Apparatus (AREA)

Priority Applications (13)

Applications Claiming Priority (7)

Publications (1)

Family

ID=34865246

Family Applications (1)

Country Status (11)

Cited By (26)

Citations (5)

• 1996
  • 1996-09-02 WO PCT/GB1996/002159 patent/WO1997009698A1/en not_active Application Discontinuation
  • 1996-09-02 AT AT96929400T patent/ATE176826T1/de not_active IP Right Cessation
  • 1996-09-02 EA EA199800261A patent/EA002337B1/ru not_active IP Right Cessation
  • 1996-09-02 ES ES96929400T patent/ES2130849T3/es not_active Expired - Lifetime
  • 1996-09-02 EP EP96929400A patent/EP0847567B1/en not_active Expired - Lifetime
  • 1996-09-02 RO RO98-00645A patent/RO119033B1/ro unknown
  • 1996-09-02 DE DE69601554T patent/DE69601554T2/de not_active Expired - Lifetime
  • 1996-09-02 DK DK96929400T patent/DK0847567T3/da active
  • 1996-09-02 AU AU68815/96A patent/AU699890B2/en not_active Ceased
  • 1996-09-02 CA CA002230459A patent/CA2230459A1/en not_active Abandoned
• 1998
  • 1998-07-28 HK HK98109456A patent/HK1008593A1/xx not_active IP Right Cessation

Patent Citations (5)

Non-Patent Citations (2)

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