Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Woven fabric – Woven fabric including an additional woven fabric layer
Reexamination Certificate
2000-07-24
2001-10-02
Cole, Elizabeth M. (Department: 1771)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Woven fabric
Woven fabric including an additional woven fabric layer
C442S251000, C442S253000, C442S261000, C442S286000, C084S414000
Reexamination Certificate
active
06297177
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to the area of drumhead construction and, more particularly, to a laminated head for a drum that includes at least two layers of synthetic plastic sheet materials and a layer of polyester or natural fiber fabric material, which is impregnated throughout with a liquid agent and bonded between the plastic sheet materials to enable the laminate to vibrate synergistically when struck by an object.
HISTORY OF THE PRIOR ART
Drumheads produced from a variety of materials are well know in the prior art. Animal skins were the first materials used to fabricate drumheads and then later synthetics became the materials of choice for the large majority of heads, particularly for those drums used to play rock, jazz and generally all varieties of contemporary music.
In contrast, animal skins have been used from the earliest of times to the present to play ethnic music. Examples of drums used to play ethnic sounds are the conga, bongo and djimbe. Natural skins, for the most part, have been preferred over synthetic materials because the sounds they produce are warm in tone. When an object strikes the head, a fundamental note is produced usually with minimal overtones. These overtones are best described as the attendant higher tones heard together with a fundamental note having a frequency of vibration that is a multiple of the fundamental note's frequency. The effect produced by the overtones is a significant disturbance of the sound, and a lessening of its quality. With a head fashioned from a natural animal skin, sound decay is relatively short (est. between 500 to 600 ms). Consequently, each note of a musical composition can be articulated.
In contrast, the synthetic materials, especially the plastics, which in many instances have been substituted for the animal skins, produce what is often described as a “pingy” sound when the drumhead is struck. The resulting sound, unlike the sounds produced by a head fashioned from an animal skin, contains many dissonant overtones. The residual high pitch ringing heard after the head is struck (commonly called “after ring”) is also a problem with heads fashioned from synthetic materials. After ring occurs when the primary and secondary notes decay at longer intervals, and mix. The result typically is a displeasing musical sound of inarticulate notes. Despite these problems, synthetic heads still have a distinct advantage over the natural skins, including the strength of the material itself and the ability to withstand the negative effects of moisture and temperature brought about by changing weather conditions. Skins can become either extremely dry or brittle. If the air is heavily humidified, skins become moist and eventually lose their tautness. In either case, it becomes increasingly difficult to maintain the desired sound consistency, and the musical quality suffers.
The present invention solves these problems in the prior art by employing a lamination of plastics and impregnated synthetic or natural fabrics which, through synergy, combine the best aspects of a head made from natural skin, including the warm and minimal overtones, and the advantages of synthetic materials, including the resistance to moisture and temperature changes.
SUMMARY OF THE INVENTION
The present invention provides for a lamination comprising an upper and a lower layer of synthetic plastic sheet materials and a layer of impregnated natural fabric sheet material sandwiched in between the two plastic layers. The substance employed to impregnate the fabric, typically a liquid or resin, causes the fabric to harden and stiffen to enable it to vibrate synergistically in concert with the vibrating synthetic plastic layers on either side.
The preferred lamination of the present invention includes upper and lower layers of synthetic plastic sheet materials and a layer of impregnated natural fabric sheet material sandwiched in between the synthetic plastic layers. Laminating adhesive is used to bond the layers together. Epoxy or a similar substance is normally applied to the top and bottom exposed surfaces of the drumhead as a protective coating.
Alternative embodiments of the present invention include the preferred embodiment of the present invention at the core or as a common component situated somewhere within the lamination. These other embodiments may include several layers of plastic and impregnated fabric sheet materials in various combinations. For example, one such embodiment includes a combination of materials in the following sequence (top to bottom): plastic, fabric, plastic, plastic, fabric. Another embodiment includes laminate materials in the following sequence (top to bottom): plastic, fabric, plastic, plastic, fabric, plastic. Substances used to impregnate the fabric may vary with the preferred and alternate embodiments. The sheet materials of the alternative embodiments are bonded together in the same manner as the materials are bonded in the laminate of the preferred embodiment. Protective coatings are similarly applied to the exposed surfaces of the laminates of the alternative embodiments.
The preferred and various alternate embodiments of the present invention generally correlate with the type of drum for which a specific drumhead is intended. For example, congas, bongos and djimbes will normally employ drumhead laminates having different thicknesses to achieve a distinct sound. Generally, the thickness of the drumhead depends on the number of plastic and fabric layers combined to comprise the lamination, although fewer, but thicker, individual layers can result in the same thickness.
Accordingly, an object of the present invention is to provide a laminated drumhead of a drum or similar musical instrument that includes a top and bottom plastic layer and an impregnated fabric layer sandwiched in and bonded between the two plastic layers.
Another object of the present invention is to provide a laminated drumhead of a drum or similar musical instrument that uses a liquid or resin to impregnate a fabric material bonded between individual layers of plastic materials to enable the impregnating substance, when hardened, to stiffen the fabric so that the fabric and the plastic layers vibrate synergistically.
Still another object of the present invention is to provide a laminated drumhead of a drum or similar musical instrument with the means to subdue the higher frequency dissonant notes inherent in plastic drumheads while retaining the desired crispness of the sound.
Yet another object of the present invention is to provide a laminated drumhead of a drum or similar musical instrument with the means to retain the strength of a plastic laminated drumhead without the inherent undesirable plastic sound.
Still another object of the present invention is to provide a laminated drumhead of a drum or a similar musical instrument with a top and a bottom plastic layer and an impregnated fabric layer sandwiched in between that produces sounds substantially similar, if not identical, to the sounds normally produced by a drumhead fashioned from a natural animal skin.
Still yet another object of the present invention is to provide a laminated drumhead of a drum or a similar musical instrument that has the look and feel of a drumhead fashioned from a natural animal skin.
Still yet another object of the present invention is to provide a laminated drumhead of a drum or a similar musical instrument that can be easily and efficiently manufactured.
Other objects and advantages of the present invention will become apparent in the following specifications when considered in light of the attached drawings wherein a preferred embodiment of the invention is illustrated.
REFERENCES:
patent: 4308782 (1982-01-01), Hartry
patent: 4362081 (1982-12-01), Hartry
patent: 5581044 (1996-12-01), Belli et al.
Belli Remo D.
Reyes Gerardo Jose
Cole Elizabeth M.
Gitlin, Esq. Larry F.
Rapkin & Gitlin
Remo Inc.
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