Music – Instruments – Drums
Reexamination Certificate
1998-06-01
2001-09-18
Nappi, Robert E. (Department: 2837)
Music
Instruments
Drums
C084S104000
Reexamination Certificate
active
06291752
ABSTRACT:
BACKGROUND
1. Field of Invention
The field of this invention relates to musical instruments and, more particularly, to percussion drum instruments.
2. Prior Developments
Conventional drums commonly comprise of a hollow cylindrical shell having a circular drum skin stretched taut over one or both of its ends. A clamping ring is attached to the shell to exert axial clamping force on peripheral edge areas of each drum skin, thus to clamp the drum skin to the shell.
A vibrational motion of the drum's skin(s) resulting from the striking action of a drumstick on the outer surface of a drum skin produces the musical output of the drum. The vibrational motion creates a sound wave, which travels outwardly through out the interior of the drum.
Drum shells are commonly made of wood, resulting in a relatively heavy, dense and expensive construction. Conventional plastic shells are generally heavy gage constructions having relatively thick dense walls.
A drum is disclosed in U.S. Pat. No. 5,353,674 issued Oct. 11, 1994 to Volpp and entitled “Shell Resonant Membranophone”. The drum is made from bent wood and has a bridge which is cut with a 45 degree bevel at an outer end to form a bearing edge for contact with the drum head membrane. However, manufacture of the drum includes producing a cylindrical member of layered wood, which is hard to form, gluing, special sand-papering to make it smooth, and special equipment to curve and form the wood, which is expensive.
Furthermore, the 45-degree bevel edge still composes a large surface area, which is contacting the head membrane. The head membrane is therefore deadened to vibration due to the large surface area of the beveled edge. The wood material making up the outer shell causes this deadened edge. This thickened surface area can not be compromised due to the lack of support the wood provides.
SUMMARY
The present invention relates to a drum including a generally cylindrical shell having two walls and having a first upper open end and a second lower open end. A rim member is disposed on both of the first upper open end and this second lower open end of the shell. A head membrane spans over the first upper and second lower open ends of the shell and has an edge portion secured between the shell and the rim member. Said two walls have thereon two cinctures at the first upper open end and the second open end second open ends of the shell and contains a wedge shaped end-bearing edge to engage the head membrane. Tension means connect at both ends and mount to both walls adjustably securing the head membrane.
The drum additionally includes the shell having a first inner wall and a second outer wall. Both the outer and inner walls extend substantially from the upper open end to the lower open end of the shell. The tension means may include a plurality of tension lugs spaced around the periphery of the shell, and a plurality of tension rods disposed within apertures of the rim member and threadedly attached to the tension lugs.
The first cincture may be disposed between the outer and inner wall of the shell and the upper head membrane, and may have a bearing edge with approximately a 45-degree bevel. The second cincture may be disposed between the inner and outer wall of the shell and the lower head membrane and may have a bearing edge with approximately a 45-degree bevel.
The drum additionally includes vertical strips positioned between the first inner wall and second outer wall shell. Said strips are placed perpendicular to the cinctures. Said vertical strips provide support of the exterior lugs, and stretch to each the upper and lower cinctures. Preferably, the shell is formed of to obtain thin walls for contact with the drum head membrane and for producing better sound.
Furthermore, the combination of thin walls constructed with thin sturdy material, and vertical wood strips which set perpendicular to the cinctures, the drums shell is mostly comprised of space. Space meaning lack of objects, and said space resides between the inner and outer shell, and is sandwiched by the said perpendicular vertical strips. It is this space which allows the a sound wave to not only penetrate the less dense shell, but resonate between the inner and outer walls.
REFERENCES:
patent: 4289056 (1981-09-01), Shier
patent: 5447087 (1995-09-01), Hawes et al.
Fletcher Marlon
Nappi Robert E.
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