Abstract:
A generally pyramid shaped sound module is provided that is attachable to a balloon for producing hi-fidelity sound effects. The sound module includes a piezoelectric element connected at the top of the pyramid shaped piezo amplification device. An electric circuit is connected to the piezoelectric element by wires. The electric circuit includes a power supply, such as one or more batteries, and the circuitry necessary for producing or reproducing a desired sound (e.g. musical notes, voices, sounds, prerecorded sound, a combination of the aforementioned, etc.). The pyramid shape allows the piezoelectric element to be coupled to the balloon without physically touching the balloon surface. Thus, even when the balloon begins to deflate, the sound quality of the sound module can be maintained.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
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   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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   REFERENCE TO A SEQUENCE LISTING 
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   BACKGROUND OF THE INVENTION 
   Electro-mechanical sound reproduction devices have been employed since the early days of cylindrical wax recordings. Simply stated, a membrane of some sort is used in a piston action to mechanically move air, creating sound waves audible to the listener. The electro-mechanical “speaker” is the result of many years of engineering, in which a paper or plastic cone is affixed to a coil of wire. The coil is supplied with an iron core, and surrounded by a magnet. This arrangement surrounds the wire in a magnetic field, forming an electro-magnet. When an alternating current (AC) signal is applied to the coil, the coil moves with a piston action (back and forth). This moves the attached cone, pushing air, creating sound. This arrangement results in high quality sound reproduction, but is very heavy and requires a large amount of power to achieve audible sound levels. 
   A different form of sound producer is available known as a “piezoelectric element”. Piezoelectric elements are small, very lightweight, and require relatively low power to produce sound. The piezoelectric element includes a crystal that produces electricity when flexed, or flexes when an electrical current is applied. The crystal is mechanically bonded to a “carrier plate”, typically a small, thin brass disk. By applying an alternating current to the piezoelectric element, sound can be produced. 
   Because of the nature of the piezoelectric element, however, it is only capable of producing certain narrow band frequencies efficiently. Typically, piezoelectric elements are used for producing single tones at a “resonant frequency” (the frequency at which they require the lowest amount of power to produce the highest sound level). Different piezoelectric elements have different resonant frequencies. 
   However, conventional piezoelectric sound producing modules suffer from a number of drawbacks. They do not provide hi-fidelity sound, the volume is generally very low, and the sound quality is very poor. Devices that do produce hi-fidelity sound are generally too heavy for attaching to a balloon and require too much power to drive the device. 
   Accordingly, it would be advantageous to produce a sound module, which employs piezoelectric elements. It would further be advantageous to produce such a sound module that is designed to: be attached to a balloon, provide hi-fidelity sound, provide higher volume, reproduce prerecorded sound, and maintain sound quality even as the balloon begins to deflate. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention provides a sound module attachable to an object. The sound module includes a piezo amplification device having a top and a bottom and an interior. A piezoelectric element is connected to the piezo amplification device substantially at the top of the piezo amplification device. The piezo amplification device is attachable to the object at the bottom of the piezo amplification device. When the piezo amplification device is attached to the inflatable object, the interior of the piezo amplification device and the inflatable object form a cavity. 
   Another aspect of the invention provides a sound module attachable to an object. The sound module includes a piezoelectric element and a piezo amplification device module for housing the piezoelectric element and for attaching the piezoelectric element to the inflatable object. The sound module also includes a circuit module electrically connected to the piezoelectric element for generating audio signals. The piezoelectric element is configured to convert the audio signals generated by the circuit module into sound that resonates within the object. 
   Still another aspect of the invention provides a method of producing sound that resonates within an object. The method includes housing a piezoelectric element at substantially the top of a piezo amplification device and electrically connecting a circuit designed to produce audio signals to the piezoelectric element. The method also includes connecting the piezo amplification device to the object in a way that forms a cavity between the piezo amplification device and the object. 
   Another aspect of the invention provides a sound module attachable to an inflatable object. The sound module includes a semi-rigid pyramid shaped piezo amplification device having a top, a bottom and an interior. The pyramid shape is formed by concentrically stacking rings such that a ring stacked closer to the top of the piezo amplification device is smaller than a ring stacked closer to the bottom of the piezo amplification device. The piezo amplification device is attachable to the inflatable object at a bottom most ring of the piezo amplification device such that when the piezo amplification device is attached to the inflatable object, a cavity is formed between the interior of the piezo amplification device and the inflatable object. A piezoelectric element is connected to one of the rings at the top of the piezo amplification device and an electrical circuit is electrically connected to the piezoelectric element. The electrical circuit is configured to generate audio signals, and the piezoelectric element is configured to convert the audio signals into sound that resonates within the inflatable object. 
   The invention will next be described in connection with certain illustrated embodiments; however, it should be clear to those skilled in the art that various modifications, additions and subtractions can be made without departing from the spirit or scope of the claims. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     For a fuller understanding of the nature of the invention, reference should be made to the following detailed description and accompanying drawings, in which: 
       FIG. 1  is a front view of a sound module in accordance with an embodiment of the invention; 
       FIG. 2  is a side view of the embodiment of  FIG. 1 ; 
       FIG. 3  is a front view of an alternate embodiment of the invention; 
       FIG. 4  is a front view of a sound module in accordance with present invention attached to a balloon sheet; 
       FIG. 5  is a side view of an alternate embodiment of the invention; 
       FIG. 6  is a front view of an alternate embodiment of the invention; and 
       FIG. 7  is a front view of an alternate embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The invention provides a sound module for attaching to a balloon. As illustrated in  FIG. 1 , the sound module  10  includes a piezoelectric element  20  connected to a piezo amplification device  30 . The sound module  10  also includes an electric circuit  40  connected to the piezoelectric element  20  by wires  60 . The electric circuit  40  includes a power supply, such as one or more batteries, and the circuitry necessary for producing or reproducing a desired sound (e.g. musical notes, voices, sounds, prerecorded sound, a combination of the aforementioned, etc.). Since the circuitry for producing a desired sound is well known to those skilled in the art, no further description is necessary and the electric circuit  40  will not be described further herein. 
   The piezoelectric element  20  includes 2 crystals  90  connected to opposite sides of a carrier plate  80 . Each of the crystals  90  are attached to the electric circuit  40 . Those skilled in the art will recognize that piezoelectric element  20  could be designed with a single crystal  90  and still fall within the scope of the present invention. 
   The piezoelectric element  20  is most efficient at its resonant frequency. By changing the piezoelectric element  20 , it can be made to be resonant at a different frequency. However, simply increasing the size of the piezoelectric element  20  may only be practical to a point, after which further increases in the size produces diminishing returns. In other words, as the mass of the carrier plate  80  increases, so does the amount of power needed to flex plate  80  and to produce higher sound levels. While for many applications the increased weight of the piezoelectric element  20  and of the power supply required to drive the piezoelectric element are not important, when the sound module  10  is to be attached to a helium filled balloon, if the weight is so heavy that it interferes with the buoyancy of the balloon, it may not be practical. 
   To overcome both the mechanical disadvantages of the increased mass and the increased power requirements, the piezoelectric element  20  is attached to a piezo amplification device  30 . The piezo amplification device  30  is preferably constructed of lightweight expanded polystyrene foam, although other materials such as cardboard, paper, plastic, some other semi-rigid material or combinations thereof may be employed. It has been determined that by forming a series of interconnected concentric rings of increasing diameter, and stacking these rings one on another, operation of the piezoelectric element  20  is enhanced at frequencies other than only the resonant frequency. By varying the width of these rings, the frequencies that are reproduced can “overlap” and be controlled, achieving a flattening of the frequency response (looking at a frequency response graph, one would normally see nodes or peaks, but varying the width of the rings flattens these nodes). It has also been determined that the thickness of the foam contributes to the efficiency of the system, and controlling the volume of the sound produced. While not preferred, those skilled in the art will recognize that a cone shaped piezo amplification device  30  is equivalent to the stepped device  30  in that a cone may be considered to be an infinite number of concentrically stacked rings of varying size. 
   In a preferred embodiment of the sound module  10  illustrated in  FIGS. 1 ,  2  and  4 , each of the rings has a ½″ width, although varying the width of each ring or of some rings can be employed to emphasize different frequencies. The height of the sound module  10  from the surface of the balloon to the top of the piezo amplification device is 3/16 of an inch. These figures are exemplary only and are in no way intended to be limiting on the scope of the invention since other dimensions may be employed. In addition to these dimensions, the corners of the steps are rounded and the height of the piezo amplification device  30  is minimized so that the sound module  10  may be run through rollers that are used to in the process of forming the balloon  50 . Again those skilled in the art will recognize that the corners need not be rounded and the height need not be minimized if the sound module  10  is to be connected to another device other than a balloon  10 . 
   As illustrated in  FIGS. 1 and 2 , the piezo amplification device  30  includes a set of concentric rings arranged in a step pattern with the smaller diameter rings being stacked on the larger diameter rings to form a pyramid like shape. In a preferred embodiment the pyramid shape is formed as an integral unit made up of the different circular rings and the corners of the rings are rounded. However those skilled in the art will recognize that the piezo amplification device  30  could be formed by attaching separate rings together. 
   As illustrated in  FIG. 2 , a preferred embodiment of the invention includes 5 steps or rings with the piezoelectric element  20  secured in the top step. However those skilled in the art will recognize that as few as 1 ring/step or more than 5 rings/steps could be employed without departing from the scope of the invention. 
   In operation, the sound module  10  is attached to the balloon  50 . Since the sound module  10  may be placed within the rollers that are used to form the balloon  50 , the sound module  10  may be secured to the interior or exterior of the balloon  50 . The sound module  10  is attached by securing the bottom portion of the piezo amplification device  30  to the balloon  50  with glue or in some other manner. When the piezo amplification device is secured to the balloon  50  a cavity is formed between the piezo amplification device  30  and the balloon  50 . The electric circuit  40  generates audio signals that are transmitted through the wires  60  to the piezoelectric element  20 . The piezoelectric element  20  responds to the audio signals by converting the signals into sounds and enunciating the same, thereby serving as a speaker. The sounds resonate off the walls of the balloon  10 , generating amplified sounds corresponding to the programmed or prerecorded sound (e.g. voice and/or music and/or some other sound). 
   While a preferred embodiment has been described, many alternatives are possible each of which falls within the scope of the present invention. One such alternate embodiment is shown in  FIG. 3 . 
   The embodiment of  FIG. 3  illustrates that the rings  70  that form the piezo amplification device  30  could be shapes other than circular rings. They could be square, rectangular, hexagonal, octagonal etc. Additionally, not all of the rings  70  have to be the same shape. As illustrated in  FIG. 3 , one or more of the rings  70  could be the same while one or more of the rings  70  could be different shapes. Those skilled in the art will recognize that the design of the piezo amplification device could range anywhere from all rings having the same general shape to no two rings having the same general shape. Additionally, one or more of the rings could have holes  110  therein (as illustrated in  FIG. 7 ). 
   Another alternate embodiment is illustrated in  FIG. 5 . In  FIG. 5 , the steps of the piezo amplification device  30  begin to rise into the pyramid as in the embodiment disclosed in  FIGS. 1–4 , but then prior to reaching the apex of the pyramid shape the steps descend before rising again. While  FIG. 5  only illustrates a single drop by a single step, multiple steps could drop down before rising again and/or there could be multiple up and down shifts. 
   In another embodiment of the invention depicted in  FIG. 6 , the piezo amplification device  30  includes a tail portion  100 . The tail portion  100  extends radially from the outermost ring and is used to support the electric circuit  40 . 
   It will be understood that changes may be made in the above construction and in the foregoing sequences of operation without departing from the scope of the invention. For example, the sound module  10  need not be connected to a balloon, but instead it could be attached to any inflatable object, to a card, to a box, etc. It is accordingly intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative rather than in a limiting sense. 
   It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention as described herein, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.