Abstract:
A drum has a polygonal shell section and a round shell section interconnected to one another to mutually define a resonant chamber. A drum head connects to the round shell section, such as by seating on a drum wall of optionally adjustable height. Acoustic properties of the drum are enhanced by the polygonal section, and can be further influenced by providing a bass port. The bass port can have an adjustable position relative to the resonant chamber to thereby influence the coupling of acoustic waves and their transmission through the bass port.

Description:
CROSS-REFERENCE TO RELATED CASE  
       [0001]     This application claims the benefit of priority under 35 U.S.C. Section 119(e) from U.S. Provisional Application Ser. No. 60/789,812, filed Apr. 5, 2006, entitled “Combination Polygon-Shelled And Round-Shelled Drum,” which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to a musical drum that has both polygon and round shell sections for the drum wall. More particularly, the present invention relates to a drum combining acoustical speaker cabinet technology with round drum shell technology to produce acoustically new generated sounds, with enhanced levels of tonality, volume and audibility, and a wider range of tunability in relation to desired usable pitch.  
       BACKGROUND OF THE INVENTION  
       [0003]     Musical drums typically produce an audible sound when struck by an object such as a drum stick. Further, musical drums typically have round shells whose diameters closely match the diameter of the struck head of the drum. However, the traditional design limits the available range of sound that can be produced from a drum.  
         [0004]     The novel device of the present invention provides a greater acoustical quality through a merger of drum technology with speaker cabinet technology. That is, the drum combines the traditional round shell with a shell section having a polygonal cross section, similar to what is used for speaker cabinetry. The novel apparatus can provide a greater resonating volume within the drum than what is available with a traditional round shelled drum. In addition, the device provides a range of sounds not producible with a shell having a single cross-sectional geometry. That is, the invention provides improved tonality, especially in the bass frequencies, because of the combination of shell sections having different cross-sections. Drums of varying sizes and shapes, including bass, tom-tom, and others, can be made in accordance with the present invention.  
       SUMMARY OF THE INVENTION  
       [0005]     In a general aspect, the present invention concerns a drum having both a polygonal shell section and a round shell section interconnected to one another and defining a resonant chamber therein. A drum head connects to the round shell section.  
         [0006]     The round shell section can include a drum wall and a rim, with the rim being shaped to mount the drum head. The drum wall communicates with and is part of the resonant chamber. The drum wall has a height that spaces the drum head and the first end of the polyhedron at a distance. That distance can be adjusted so as to influence a tonal quality produced by the drum.  
         [0007]     In a further aspect of the invention, a bass port can be supported by the polygonal shell section to provide an acoustic wave vent from the resonant chamber to an exterior of the drum. The bass port can be an opening into the resonant chamber. The bass port can be disposed at a location near a corner of the polygonal shell section. The bass port can be positioned away from a direct acoustical path of the drum head.  
         [0008]     In more particular aspects, the bass port can comprise a tube having an inlet for coupling an acoustic wave from within the resonant chamber and an outlet for communicating the acoustic wave to an exterior of the dram. When embodied as a tube, the tube can be movable relative to the polygonal shell section. Thus, the tube can be translatable between an extended position in which the inlet is proximate to the polygonal shell section and a retracted position in which the inlet is positioned toward a center of the resonant chamber. Also, the tube can be rotationally positionable so as to alter the effective aperture of the inlet. A seal can be provided within the resonant chamber that cooperates with the rotationally positionable tube so as to at least partially close the inlet. Also, the bass port can include a valve  280  suitable for opening and closing the outlet.  
         [0009]     Further aspects, structural features, and advantages can be appreciated from the accompanying description of certain embodiments and the drawing figures thereof. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of an embodiment of a drum in accordance with the present invention;  
         [0011]      FIG. 2  is a plan view of one side of an embodiment of a drum in accordance with the present invention;  
         [0012]      FIG. 3  is a a plan view of the top of an embodiment of a drum in accordance with the present invention;  
         [0013]      FIG. 4  is a perspective view of an embodiment of a drum in accordance with the present invention, further showing an optional bass port or vent;  
         [0014]      FIG. 5  is a plan view of one side of an embodiment of a drum in accordance with the present invention;  
         [0015]      FIG. 6  is a plan view of the top of an embodiment of a drum in accordance with the present invention;  
         [0016]      FIG. 7  is a perspective view of an embodiment of a drum in accordance with the present invention;  
         [0017]      FIG. 8  is a perspective view of an embodiment of a drum in accordance with the present invention;  
         [0018]      FIG. 9  is a plan view of one side of an embodiment of a drum in accordance with the present invention; and  
         [0019]      FIGS. 10A and 10B  are plan views of an embodiment of a drum further including an adjustable bass port in accordance with certain further aspects of the present invention 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0020]     The detailed description set forth below in connection with the appended drawings is intended as a description of the presently-preferred embodiments of the invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the functions and the sequence of steps for constructing and operating the invention in connection with the illustrated embodiments. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.  
         [0021]     Referring to  FIG. 1 , the combination polygon-shelled and round-shelled drum  10  comprises a first round-shelled section  20 , a polygon-shelled section  30 , a drum head  40 , and a means  50  for connecting the drum head  40  to the first round shelled section  20 . In an embodiment of the invention as shown in  FIGS. 2-10A  and  10 B, the drum  10  may further comprise a second round-shelled section  60 . The polygon-shelled section  30  further comprises at least three flat sides, interconnected to form a polyhedron. The polyhedron forms the side walls of a resonating chamber having a first end and a second end. The first round-shelled section  20  is connected to the first end of the polygon-shelled section  30 , while the second round-shelled section  60 , if any, is connected to the second end of the polygon-shelled section  30 .  
         [0022]     The first round-shelled section  20  may further comprise a cylindrical drum wall  80 , having a rim  90 . The rim  90  is shaped to accept the drum head  40 . The drum head  40  may comprise a resonant membrane and may be of any shape, such as circular, oval, or otherwise. The height  85  ( FIG. 6 ) of cylindrical drum wall  80  defines the distance between drum head  40  and the first end of the polygon-shelled section  30 . Height  85  is preferably between 1 and 4 inches, however there is no upper limit. This ranges allows the round-shelled section  20  to adapt to standard industry hardware and mounting options. Having a height of at least 1 inch or greater gives the drum more sound options, a larger tonal-range and increased sustain and decay properties, enriching the drum in lower frequency tones and giving the drum a greater number of sound combinations. This provides for a desirable distortion to be made acoustically rather than electronically enhanced by an FX processor. Height  80  effects the sound output of the drum by increasing the internal space, mass and volume of the drum. Pitch or tone output by the drum is dependent on height  85 . In one embodiment, the height and hence the distance between the drum head and the first end of the polyhedron is adjustable. Adjustments can be made by physically moving the drum wall or an adjacently mounted surface. Such movement can be by rotation (e.g., a threaded mounting of the drum wall) or by translation (e.g., a ratchet or selectively clamped slideable connection). The adjustment is preferably made by a movement that secures the drum head in a stable position suitable for drumming on the drum head, and preferably is air tight. By mounting the drum wall relative to the polygon-shelled section in a movable manner, more sound options result which enable the pitch and tone of the drum to be changed.  
         [0023]     In the preferred embodiment, the drum head  40  is of a size and shape that is standard in the art. For example, drum heads are typically round and have a diameter between eight and forty inches, depending on the type of drum. Although the thickness of the cylindrical drum wall  80  can be any suitable dimension, in the preferred embodiment the width of the cylindrical drum wall  80  is between one quarter inch and one inch thick. Although the diameter of the rim  90  can be any suitable dimension, in the preferred embodiment the diameter is twelve inches. Other commonly used diameters might be between eight and forty inches. Further, although the bearing edge of the rim  90  (i.e. where the drum head  40  contacts the round-shelled section  20 ) can be any suitable angle, in the preferred embodiment the bearing edge angle is forty-five degrees. Although the height of the cylindrical drum wall  80  can be any suitable dimension, in the preferred embodiment that height is between two inches and four inches.  
         [0024]     The polygon-shelled section  30  further comprises at least three flat sides  100 , where the flat sides  100  are polygonal and are interconnected to form a polyhedron. The flat sides  100  can be of any polygonal shape, including the rectangular configuration depicted in  FIGS. 1-6 , the trapezoidal shape of  FIG. 7 , and the octagonal version as depicted in  FIGS. 8-9 . The polyhedron forms an at least partially enclosed resonating chamber, having a first end and a second end and having an interior and an exterior. The interconnections on the interior and on the exterior of the resonating chamber may be angular, or they may be arcuate. Further, the first end and the second end may define planes that are parallel to each other, or the planes may be nonparallel. In the preferred embodiment, there are four flat sides  100 , which are rectangular and interconnect to form a hexahedron, where the first end and the second end are opposite each other and are essentially parallel to each other, as shown in  FIG. 1 . Referring to  FIG. 2 , one end which supports the first round-shelled section  20  is non parallel to its opposing wall. Referring to  FIG. 3 , both ends that support respective round-shelled sections  20  are non-parallel to one another. Although the wall thickness of the flat sides  100  can be any suitable dimension, in the preferred embodiment the wall thickness is between one quarter inch and one inch. Further, although the length of the flat sides  100  can be any suitable dimension, in the preferred embodiment the length is fourteen inches. Other commonly used lengths might be between ten and twenty inches or more.  
         [0025]     The shape of the first end of the polygon-shelled section  30  is such that the geometry of the polygon-shelled section  30  blends with the circular geometry of the first round-shelled section  20 . In the preferred embodiment, the first end is flat, has a wall thickness between one-quarter inch and one inch, and has a circular cutout that essentially matches the outer diameter of the cylindrical drum wall  80 . The second end of the polygon-shelled section  30  may be left open, may be closed by a panel, or may be shaped such that the geometry of the polygon-shelled section  30  blends with the circular geometry of the second round.-shelled section  60 , if any. For example, the blend can result in an uninterrupted resonant chamber, that is, a connection between the polygonal section and the round section with no lip or flange extending into the polyhedron resonant chamber.  
         [0026]     The first round-shelled section  20  or the second round-shelled section  60  may be centered within the first end or second end, respectively, of the polygon-shelled section  30 , as generally depicted by the figures. Otherwise, either or both may be off-centered. In embodiments including the second round-shelled section  60 , its rim can be left open (i.e. without a drum head). Alternatively, its rim can be fitted with a drum head as with the first round-shelled section. If so, the second drum head can act as a non-struck, resonant head, or it can be a second struck head.  
         [0027]     The ratio between the height of the first round-shelled section  20  or the second round-shelled section  60  and the height of the polygon-shelled section  30  varies in different embodiments of the invention. This variation permits different tonal qualities to be produced by the drum  10 . In the preferred embodiment, the height of the polygon shelled section  30  is between two times and four times the height of the first round-shelled section  20  or the second round-shelled section  60 . In the preferred embodiment, the height of the first round-shelled section  20  is equal to the height of the second round-shelled section  60 .  
         [0028]     Referring again to  FIG. 4 , a drum having a polygon-shelled section  30  as previously described can include a bass port  200  in communication with the resonant chamber and an exterior of the drum so as to redirect inward pressure outward. A drum  10  provided with a bass port can supplement or assist in low-frequency acoustic wave venting from the drum. The bass port can comprise an opening into the resonant chamber, as shown in  FIG. 4 . Plural openings can be provided, such as at locations near the corners of the polygon-shelled section  30 , on a single side of the polygon or on opposite sides (e.g., top and bottom). Preferably, the bass port is positioned so as to not be directly in line with the drum head so that the acoustic waves that it couples are those that fill the resonant chamber. Optionally, a microphone mount can be included for placement of a microphone at or within the bass port  200 .  
         [0029]     Referring now to  FIGS. 10A and 10B , an adjustable bass port  210  can be provided in accordance with further aspects of the present invention. The bass port  210  includes a collar  220  seated in a fixed position upon a side panel of the polygon-shelled section  30 , preferably so as to not be directly in line with the drum head so that the acoustic waves that it couples are those that fill the resonant chamber. A vent tube  230  is positioned within the collar  220 , preferably such that it can be rotationally positioned, slideably positioned, or both (as shown). The tube  230  has an outlet  240  which permits pressure waves to vent from within the resonant chamber of the drum to the exterior. The tube  230  also has an inlet  250  which receives pressure waves from the resonant chamber for conveyance through the tube to the outlet  240 .  
         [0030]     In one embodiment, the inlet  250  is positionable relative to the interior walls of the polygon-shelled section  30  so as to reduce the size of or even completely close the inlet  250 . In  FIG. 10A , the inlet is oriented so as to be disposed against a surface  260 , which optionally is made of a material which flexes to form a seal (e.g., a foam or rubber gasket) or which can have a shape that permits the outlet  240  to be rotated to and past it. In the orientation shown in  FIG. 10A , pressure waves within the resonant chamber of the drum are not vented to the exterior. In the orientation shown in  FIG. 10B , which is achieved by rotating the bass port  210 , pressure waves within the resonant chamber of the drum are conveyed through the tube  230  to the outlet  240  so as to assist in the delivery of low-frequency waves.  
         [0031]     In another embodiment, the inlet  250  is positionable so as to extend at various lengths toward the center of the resonant chamber. By translating the inlet  250  deeper into the polygon-shelled section  30 , different acoustic waves are coupled at the inlet  250 , which means that the sound emanating from the outlet  240  can be varied. In  FIG. 10A , the inlet is fully positioned within the resonant chamber. In this position, a flange  270  abuts the collar  220  and prevents the bass port  210  from falling into the drum. Optionally, the inlet can be oriented over a range of rotatable positions, as described above, to couple less, more or different waves from within the resonant chamber. In  FIG. 10B , the tube  230  has been partially retracted, such as by drawing the flange  270  outward, away from the polygon-shelled section  30 . As a result, the inlet is positioned closer to the interior wall of the polygon-shelled section  30  and couples waves differently than when fully advanced into the chamber. Again, the inlet can be oriented over a range of rotatable positions, as desired, to couple and vent acoustic waves in a desired way.  
         [0032]     In another embodiment, the tube  230  includes a valve  280  which can be manipulated in order to open or close the outlet  240 , as well as to change the effective size of the outlet. The valve can be provided in addition structure suitable for enabling rotational and/or translational movement of the bass port  210 , or can be provided instead of such structure.  
         [0033]     In a variation of the foregoing, the inlet can have a shape selected to assist in the coupling of acoustic waves. As one non-limiting example, the inlet can have an opening cut at a 45° angle to its supporting structure. Thus, it can be cut 45° relative to the axis of the tube  230  that is adjacent to the inlet.  
         [0034]     As will be appreciated by persons of ordinary skill in the art, a drum so-constructed to include the polygon-shelled section  30  in combination with a round-shelled section  20 , with our without a bass port, can be used as a bass drum or as a rack Tom if placed on a stand.  
         [0035]     The drum head connecting means  50  may comprise a fastening means such as a counter hoop  110  of the type known in the art, another type of mounting flange, or glue. Further, a counter hoop or a mounting flange may further comprise tension rods  120 . The tension rods  120  may connect the counter hoop  110  or a mounting flange to jewelry hardware  130 , or lugs, of the type known in the art and depicted in  FIG. 1 . Alternatively, the tension rods  120  may connect the counter hoop  110  or a mounting flange directly into the polygon-shelled portion of the drums  10 . As an alternate using lugs, insert screws directly to the top and bottom perimeters can be used. The can be applied directly over the tension rods and a standard steel or die cast triple flanged mounting hoop.  
         [0036]     In an embodiment of the invention, the drum  10  may further comprise a means for tuning the drum head  40 . The drum head tuning means may comprise jewelry hardware  130  (i.e. lug and lug nut) of the type known in the art and depicted in  FIG. 1 , adjustment of the tension rods  120 , or any other means for adjusting the tension of the drum head  40  while it is mounted on the rim  90 .  
         [0037]     In some embodiments of the invention, one or more of the flat sides  100  may have an additional round-shelled section. In such embodiments, those additional round-shelled sections may further comprise a drum head and a means for connecting the drum head to the additional round-shelled section, as described for the first round-shelled section  20 .  
         [0038]     In some embodiments of the invention, one drum head may be significantly smaller than another. In those embodiments, the flat sides  100  may be tapered toward the smaller drum head. An example of such an embodiment is depicted in  FIG. 7 . This tapering can produce unique acoustic effects similar to the pressure differential produced in a nozzle. That is, the acoustic wave produced at the striking drum head may be either diluted or concentrated as it travels through such a tapered cabinet, depending on the orientation of the tapering along the direction of the traveling acoustic wave. Of course, this tapering is equally contemplated for configurations containing two drum heads of substantially equal size. Additionally, this effect of diluting or concentrating the acoustic wave may equally occur in only a portion of the distance the wave travels through the cabinet space, such as where the tapering or beveling is limited to only a portion of the cabinet as illustrated in  FIG. 9 .  
         [0039]     The drum  10  may be made of any suitable material, such as acrylic resin, wood, plastic, metal, glass, or laminated composites. If the drum includes transparent or translucent sections or partial sections, it can be illuminated from within. Although illumination within a drum is conventional, illumination of the polygon-shelled section provides a dramatic new visual effect. Optionally, such lighting can be modulated to change in time such as with the beat of ambient music or the beat of the drum itself.  
         [0040]     Optionally, the resonant chamber can be pressurized or depressurized to change the pitch or tone output by the drum. One of the side walls of the polygon-shelled section can have an aperture and a tube having a first end extending from the aperture to provide a fluid path (e.g., air) into and out of the drum. A second end of the tube can be connected to an air source, for example, which can introduce or evacuate air from the resonant chamber of the drum and thereby alter its pitch or tone.  
         [0041]     While the present invention has been described with regards to particular embodiments, it is recognized that additional variations of the present invention may be devised without departing from the inventive concept. In view of the above, it will be seen that several objects and advantages of the present invention have been achieved and other advantageous results have been obtained. It should be understood that any feature disclosed with respect to one embodiment of the invention can be equally applied to any other disclosed embodiment of the invention to yield additional benefits of the combined features.  
         [0042]     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing form the spirit and scope of the invention.