An accordion having a treble section, a bass section and an interposed bellows has a porous partition member disposed between the bass and treble sections, the partition member having a plurality of electrical microphone pickup devices disposed over complementary depressions formed in the partition on the side of the partition member adjacent the treble section of the accordion, the diaphragm of the ceramic microphone facing toward the partition member.
What I claim is
1. An accordion comprising:
2. The accordion of claim 1 in which said depression in said partition member is on the surface of the partition member facing said treble section.
3. The accordion of claim 2 in which said electronic microphone pickups are mounted on said partition member, the diaphragm of said electronic microphone pickup facing towards said partition member.
4. The accordion of claim 3 in which the diaphragm of said electronic microphone pickup is at least partially inserted within at least one of said depressions.
5. The accordion of claim 1 in which there are a plurality of depressions in said partition panel, said depressions being non-symmetrically placed in said partition member.
6. The accordion of claim 1 in which said partition member is made of balsa wood.
7. The accordion of claim 1 in which said depressions have side walls and a bottom surface.
8. The accordion of claim 7 in which said bottom surface of at least one of said depressions is parabollic.
9. In an accordion having a treble section, a bass section and a bellows, a muting member positioned between said bass section and said treble section, said muting member comprising a substantially rectangular partition member, said partition member having at least one depression therein forming a resonating chamber, and at least one electronic microphone pickup associated with said depression and mounted on said partition member, the diaphragm of said microphone pickup facing said partition member.
10. In the accordion of claim 9 the partition member further comprising a porous material.
11. In the accordion of claim 10 the partition member being balsa wood.
12. In the accordion of claim 9 in which the diaphragm of at least one of said electronic microphone pickups is inserted at least partially within at least one of said depressions.
BACKGROUND OF THE INVENTION
This invention relates to an improved accordion having a novel sound filtering element and an improved electrical pickup. The accordion has a first spaced portion forming a treble section and a second spaced area forming a bass section. The bass and treble sections are connected by a bellows which forces air to pass through reeds located in the bass and treble sections when compressed or expanded. The passage of air through such reeds results in the generation of a sound tone. Appropriate switching elements, controlled by piano type keys on the treble section and buttons on the bass section, act to open or close the openings to selected reed switches, thus selecting the desired notes to be generated.
Following the compression or depression of the bellows, substantial forces of air are generated within the bass and treble sections of the accordion. Due to the generally closed rectangular shape of the accordion the forced air is subject to extensive deflections resulting in the generation of undesired repetitions or harmonics of the desired note.
When the accordion is to be used in large concert halls or in other atmospheres which require amplification of the tones generated by the accordion the assistance of electronics by use of microphone pickup is required. The microphone may be entirely external of the accordion such as stage microphones. However, such amplification is entirely unsatisfactory for the quality reproduction of the tones and, of course, should the accordion be part of an orchestra such stage microphone would be entirely inappropriate.
In U.S. Pat. No. 2,639,640, E. Felice discloses the use of a solid panel mounted between the treble and bass sections to "isolate" the treble and bass sections to obtain an improved tonal quality. As stated in the Felice patent, it is preferable that a "solid" panel be used. No electronic pickup is disclosed in the Felice patent.
U.S. Pat. No. 2,658,420 to W. Pompili also discloses the use of a partition panel mounted between the treble and bass sections of the accordion. The panel is disclosed as being of any suitable material such as "wood, plastic, or pressed board. The panel may also be covered or coated with a sound-absorbent material such as felt, if the player desired soft tone . . . ". The panel of Pompili has a concave portion centrally located positioned below a single electronic microphone pickup, suspended from the reed banks in the center of the treble section. This was intended to overcome the objection of a localized electronic microphone pickup from tending to be more sensitive to the sounds produced by the vibrations of the reeds closest to the pick up. The concave portion of the panel serves to focus the sound waves generated on the microphone.
In U.S. Pat. No. 2,577,288 to Terlinde, a microphone pickup was placed on a baffle plate attached to one of the reed blocks on the treble section with the diaphragm of the microphone pickup facing the baffle plate. The baffle plate, designed to assure "mixing" of the sound waves, consisted of a brass plate having opposite extending arms in the plane of the plate for mounting the baffle and a number of upwardly extending ears projecting from the plate towards the microphone pickup to retain the microphone.
In each of the above-referred to prior art patents, the microphone pickup was attached in some manner to the reed banks, very close to the source of the generated sound.
SUMMARY OF INVENTION
In the present invention an accordion of conventional construction having a treble section separated by an interposed bellows from the bass section has a porous partition or panel substantially separating the bass and treble sections. In the preferred embodiment the panel is made of balsa wood. A plurality of resonating chambers are formed in the porous partition which is a generally planar shape. The resonating chambers are in the form of depressions in the porous partition on the side of the partition facing the treble section. In the preferred embodiment the depressions are circular in shape and are of substantially the same diameter as the microphone pickup.
The microphone pickup is mounted suspended over its complementary depression, the diaphragm of the microphone pickup being inserted in the preferred embodiment at least partially within its associated depression, so that the diaphragm is facing toward the partition member and away from the treble section.
Appropriate air slots are provided at the sides of the partition to permit the flow of air between the treble and bass sections of the accordion. The partition is supported on a layer of foam-like material to prevent vibrations from the accordion being transmitted to the partition panel.
The present invention permits the substantial elimination of upper harmonics which may be present in the generated sound waves of the accordion and permits the generation of substantially sinusoidal sound waves. In addition, the suspension of the microphone pickups in close proximity to the resonating chambers and distant from the reed banks provides a substantially improved tone from the tones previously available. In addition, the construction of the partition panel and the electronic pickups are inexpensive and may be readily fitted in a conventional accordion.
It is an object of the present invention to provide an accordion having an improved tone.
A further object of the present invention is to provide an improved accordion having an electronic pickup which provides a sinusoidal output.
A further object of the present invention is to provide an improved accordion which is inexpensive to manufacture.
An additional object of the present invention is to provide an improved accordion in which a muting board and electronic pickups for such board may be easily attached to a conventional accordion.
Yet another object of the present invention is to provide an improved accordion in which the electronic microphone pickups are suspended at a distance from the reed banks.
Finally, a further object of the present invention is to provide an inexpensive muting partition.
FIG. 1 is a top view of an accordion embodying the present invention with a partial section showing the planar partition panel.
FIG. 2 is a plan view of FIG. 1 taken along section lines 2--2 of FIG. 1.
FIG. 3 is a reduced side sectional view of the engagement between the treble and bellow sections and the partition panel.
FIG. 4 is an enlarged sectional view of a resonating chamber and microphone pickup.
FIG. 5 is an enlarged sectional view of a resonating chamber and microphone pickup with the diaphragm of the pickup above the chamber.
FIG. 6 is an enlarged sectional view of a modified resonating chamber.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring to FIG. 1 an accordion 10 is shown having a conventional treble section 12, a bass section 14, and a bellows 16. The treble section 12 includes a plurality of treble reeds (not shown) which generate a sound wave in response to the compression or expansion of the bellows 16. The individual treble reeds are activated in response to the depression of piano-type keys 18. The bass section 14 has a plurality of bass reeds (not shown) which are controlled in response to the depression of buttons 20. Interposed between the treble section 12 and the bass section 14 is a porous partition 22 which rests upon the lip 24 of the casing 26 of the treble section. As shown in FIG. 3, a foam-like or rubber resilient material 28 acts as a cushion between the partition member 22 and the casing 30 of the bellows.
Referring to FIG. 2, the partition panel may be seen in a plan view. The partition panel is of generally rectangular planar shape and substantially separates the treble section 12 from the bellows opening. Air gaps 30 for permitting the flow of air between the treble section 12 and bass section 14 are provided in the panel.
The partition member 22 is of a generally sound absorbing material having a porous characteristic. In the preferred embodiment, the partition panel is approximately one-half inch thick and is made of balsa wood. However, other porous materials may be used.
The partition panel 22 has at least one depression or resonating chamber 32 as illustrated in FIG. 1 on the side of the panel facing the treble section 12. The depressions in resonating chambers 32 are in the preferred embodiment of a circular cross section. However, alternate resonating chambers having different cross-sectioned shapes may be employed. The resonating chamber 32, shown in an enlarged sectional view in FIGS. 4 and 5, comprises a depression in the partition panel 22 to a depth of about one-half the thickness of the width of the partition panel although the depth of the depression may be greater or lesser. Referring to FIG. 6, an alternate embodiment of the resonant chamber 33 is portrayed. This resonant chamber 33 is of a parabolic construction which directs the sound waves at a central focus point.
Above each resonant chamber 32 is suspended an electronic microphone pickup 34. The diaphragm 36 of the microphone pickup 34 faces the partition panel 22 and in the preferred embodiment is at least partially inserted within the resonant chamber 32 such as shown in FIG. 4. Referring to FIG. 5, the diaphragm 36 is shown suspended above the depression chamber 32.
The diameter of the diaphragm 36 is approximately the same diameter as the opening of the resonant chamber 32. The microphone pickup 34 has two projections 38 extending laterally from the microphone pickup. Rubber grommets 40 support the microphone pickup 34 above the partition panel 22. Screws 36 passing through the projections 38 and the rubber grommets 40 and into the partition panel 22 fix the microphone pickup 34 above the partition panel 22.
The electronic microphone pickups 34 are connected electronically in parallel to one another by wires 36 and by conventional circuitry to an amplifier 38 and speakers 40. The amplifier 38 may be removably connected by means of a connector jack combination 42.