Classifications

• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10D—STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR
  • G10D13/00—Percussion musical instruments; Details or accessories therefor
  • G10D13/01—General design of percussion musical instruments
  • G10D13/02—Drums; Tambourines with drumheads
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10D—STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR
  • G10D13/00—Percussion musical instruments; Details or accessories therefor
  • G10D13/10—Details of, or accessories for, percussion musical instruments
  • G10D13/20—Drumheads
• • G—PHYSICS
  • G10—MUSICAL INSTRUMENTS; ACOUSTICS
  • G10D—STRINGED MUSICAL INSTRUMENTS; WIND MUSICAL INSTRUMENTS; ACCORDIONS OR CONCERTINAS; PERCUSSION MUSICAL INSTRUMENTS; AEOLIAN HARPS; SINGING-FLAME MUSICAL INSTRUMENTS; MUSICAL INSTRUMENTS NOT OTHERWISE PROVIDED FOR
  • G10D13/00—Percussion musical instruments; Details or accessories therefor
  • G10D13/10—Details of, or accessories for, percussion musical instruments
  • G10D13/25—Details of, or accessories for, percussion musical instruments for changing the sound or tone

Definitions

• the present invention relates generally to a drum structure and more particularly to an improved drumhead and means for producing momentarily a large change in the fundamental pitch of a drum when the drum is struck a sharp blow; thereby adding interest and color to the usual rhythmic role of a drum.
• the playing characteristics of a drum which a drummer desires depends on the musical style of the drummer and on the type of music played.
• Various means are presently employed to affect the playing characteristics of a drum, such as a tom-tom type drum, and modify the modes thereof. Normally, equal tension is applied to the drumhead in all directions. When the tension is uneven beats are heard when the drum is struck. If it is desired to shorten the decay time of the drum modes and give the drum a dull tone quality, dampen ⁇ ing means are used, such as attaching a piece of cloth to the drum membrane or taping a small patch of cloth or plastic foam to the drumhead membrane. ⁇ Other means are used for increasing the amount of pitch change produced when the drum is struck a sharp blow.
• OMPI have a change in frequency as a function of the displacement thereof.
• Electronic means have also been used to produce a simulation of a pitch change, but such means are expensive and not practical for many to use.
• Fig. 1 is a perspective schematic view of a drum having a compound drumhead of the present invention mounted on one end thereof;
• Fig. 2 is a schematic vertical sectional view of the drumhead of Fig. 1;
• Fig. 3 is a schematic vertical sectional view of a modified form of the drumhead invention of the present invention;
• Fig. 4 is a schematic vertical sectional view of a further modified form of the drumhead invention of the present invention.
• Fig. 5 is a schematic vertical sectional view of a still further modified form of the drumhead invention of the present invention.
• Fig. 6 is a schematic top plan view of a further modified form of the present invention.
• Fig. 6a is a schematic vertical sectional view of the construction shown in Fig. 6;
• Fig. 7 is a schematic top plan view of a still
• Fig. 7a is a schematic vertical sectional view of the construction shown in Fig. 7;
• Fig. 8 is a graph of the static deflection pro- prised in the compound drumhead of Fig. 1 and a uniform drumhead by an applied effective mass
• Figs. 9, 10 and 11 show graphs of the ratio squared of the large amplitude resonance frequency to the small amplitude resonance frequency of the compound drumhead of Fig. 1 and a uniform drumhead plotted against the resultant displacement at the center of the drumhead for the fundamental mode of the drum when the only difference is the initial tension applied to the drumhead
• Fig. 12 comprises a family of curves showing the affect of a change in the dimensions of a com ⁇ pound drumhead on the pitch modulation produced during play of the drum.
• the improved drum structure in accordance with a preferred embodiment of the present invention comprises a drum with a generally cylindrical body having mounted on at least one end thereof a com ⁇ pound drumhead which in the form shown in Figs. 1 and 2 comprises a conventional flexible, stretch- resistant uniform drumhead membrane adapted for mounting on a drum and having integrally secured to one surface of the drumhead membrane a ring ⁇ like section of flexible stretch-resistant material to provide a drumhead having an inner center section or portion having a predetermined average thickness generally of substantially uniform thickness provid ⁇ ing an area adapted to be struck by drum sticks during play of the drum and an outer section or portion of flexible, stretch-resistant material of increased average thickness generally of substant ⁇ ially uniform thickness disposed around the center portion, preferably extending from the center por ⁇ tion outwardly to the outer edge of the drumhead.
• the outer ring-like section or portion of increased thickness is preferably formed of the same flexible, stretch-resistant material as the uniform drum- head membrane and is securely affixed to the drum ⁇ head membrane over the entire area thereof by a thin, flexible layer of adhesive material to provide a continuous unitary compound drumhead structure having a portion thereof which increases the resis- tance to stretch when struck by a drumstick without adding a large amount of mass to the drumhead and effecting an undesirable lowering of the normal pitch of the drum.
• the outer ring-like portion has a width less than the radius of the drumhead and provides a drumhead with an outer section of increased average thickness with a central area preferably of substantial uniform thickness which has an average thickness less than the remainder of the drumhead and provides an area sufficiently large to be struck with drum sticks during normal play.
• the width of a ring-like outer portion or ring ⁇ like construction which is adapted to be mounted on a drumhead membrane as described herein can be determined by selecting an outer portion or ring member of a width which produces a pitch change most pleasing to the musician or most suitable
• OMPI for the type of music being played.
• the width of a Mylar-type ring member or ring-like construction of the type which extends inwardly from the outer supporting edges of the drumhead formed of Mylar- type drumhead material and having a substantially uniform thickness which should be used to produce the optimum momentary pitch modulation or pitch change can be determined by referring to Fig. 12 of the drawing.
• Figure 12 shows a family of curves represent ⁇ ing the ratio squared of the resonance frequency (w) to the natural or small amplitude frequency (wo) of a drumhead plotted against the ratio ID/OD or "0D-2RW/0D" wherein “ID” is the inner diameter or play area of a drumhead membrane, “OD” is the diameter of the drumhead membrane within-the outer supporting edges thereof and “RW” is the width of the ring member, and where the drumhead has 3- radius of .165 meters, a drumhead membrane thick ⁇ ness of .000254 meters, and a ring thickness rang ⁇ ing between 0 and .002032 meters in steps of .000254 meters.
• the resonance frequency at the primary mode of the drum was maintained constant at 80 Hertz (Hz) and the amplitude at the drumhead cente " r was equal to .005 meters.
• the curve No-. 1 was derived using a plain Mylar drumhead having no outer ring member and each of the curves No. 2 through 9 was derived using a Mylar ring member of progressively increasing thickness as indicated which was mounted integrally on the said drumhead membrane.
• the points of maximum pitch change for each ring thickness are connected by an asymptotic curve (M) .
• the preferred operat ⁇ ing range of the ratio of ID (diameter of the cen ⁇ ter portion of the drumhead) to OD (diameter of the drumhead membrane) is between about 0.3 to 0.9 with the absolute theoretical maximum ratio ap ⁇ proaching 0.7.
• Fig. 12 shows the optimum pitch change will be obtained where the ratio of ID/OD is about 0.46.
• a Mylar or Mylar-like ring .000254 meters thick having a width of 3.5 inches mounted on the said drumhead membrane provides a momentary pitch increase of about 8 percent.
• a thicker ring of the same width would provide a greater pitch in ⁇ crease.
• the thickness of the ring in addition to the width of the outer portion or ring ⁇ like construction having an affect on the momentary change in pitch, the thickness of the ring also has an important affect on the str'etch-resistance and therefore the pitch change produced when the drumhead is struck with a drumstick.
• Fig. 12 in addition to the width of the outer portion or ring ⁇ like construction having an affect on the momentary change in pitch, the thickness of the ring also has an important affect on the str'etch-resistance and therefore the pitch change produced when the drumhead is struck with a drumstick.
• the ring member is formed of a material which has a significantly different modulus of elasticity and provides greater resistance to stretch than Mylar or Mylar-like drumhead material
• the ring member of the same width and thickness as the Mylar ring section would produce a greater change in pitch.
• a thin flexible metallic ring such as metallic aluminum which has about 10 times the resistance to stretch as Mylar, would produce a much greater pitch modulation than the Mylar ring without adding significantly to the mass of the drumhead.
• a thin flexible stainless steel ring or metallic alloy ring would produce a larger change in pitch than the Mylar ring and can be used where special pitch modulations effects are desired.
• a compound drumhead embodying the present invention having a relatively thinner inner center section or portion having a predetermined average thickness and an outer section or portion extending radially outwardly therefrom having a greater average thickness can be formed as a unitary, homogenous, structure by molding the drumhead mem ⁇ brane of a suitable plastic material which is dur-
• OMPI able, flexible and stretch-resistant to provide the center section preferably having a substantial uniform thickness and an outer ring-like section surrounding the center section which has a substanti-
• a drumhead having the improved features of the present invention can also be made by forming the outer ring-like section on a conventional drumhead membrane as a liquid coating which on drying forms
• drumhead membrane such as by spraying or flowing a liquid flowable material onto a template or by painting.
• liquid material dries, it forms a uniform adherent, unitary stretch-resistant outer section of increased average thickness integral
• FIG. 1-2 of the drawing A preferred embodiment of the present inven ⁇ tion is shown in Figs. 1-2 of the drawing where ⁇ in a drum 10 has a generally circular drumhead
• the ring member 15 formed of a flexible material resistant to stret- ching, such as Mylar plastic or metalized Mylar plastic in sheet form (Mylar is a trademark of E. I. duPont deNemours & Co. and is formed of poly ⁇ ethylene terephthalate resin) or similar material, which preferably has a uniform thickness of- the same order of magnitude as the drumhead membrane 11 and having a width about half the radius of the drumhead extending inwardly from the outer edge of the drumhead membrane 11.
• the ring member 15 is secured to the outer surface of the drumhead by a layer of flexible adhesive 17, such as contact cement, so as to securely affix the ring member 15 to the surface of the drumhead 11 and form a unitary structure.
• a typical ring ⁇ like member 15 can have a width ranging from about 0.02 m to 0.660 m (1 inch to 26 inches), a thick ⁇ ness between about .0000254 m to .00254 m (1 mil to 100 mil) and in every instance a width less than half the diameter of the drumhead so that the drum can be played in the usual manner without striking the ring-like member.
• Fig. 3 of the drawing shows a modified form of the improved drumhead structure in which the compound membrane 20 forming the drumhead is a unitary, homogenous structure formed by molding or casting a plastic drumhead material, such as Mylar, so as to form an inner generally circular section 21 having a uniform or substantially uniform thickness and an outer ring-like section 22 having a substantially uniform thickness greater than the thickness of the inner section 21.
• a plastic drumhead material such as Mylar
• Fig. 4 shows a further modified form of the invention in which the compound drumhead membrane
• the outer ring-like section is formed by applying a layer of liquified drumhead material which when solidified forms a unitary flexible stretch-resistant section of substantially uniform thickness affixed to the surface of the membrane 31 without requiring the use of an adhesive layer to securely attach the ring member to the drumhead membrane 31.
• the so-called compound drumhead can have the configuration shown in Fig. 5 wherein the drum ⁇ head 40 is thinnest at the center 41 and progress ⁇ ively increases in thickness as the distance from the center increases, as at 42.
• the center thin portion can be widened to form a ani- formly thin circular portion, at the center of the drumhead as in Figs. 1 and 2 of the drawing with the outer ring-like portion increasing progress ⁇ ively in thickness as the distance from the center circular portion increases.
• Figs. 6 and 7 show a generally ring-like construc ⁇ tion mounted on a drumhead in which portions of
• a Ludwig tom-tom having a cylindrical main body section 13 inch in diameter was provided with a standard simple uniformly thick metalized Mylar drumhead membrane for mounting on one end of the torn—torn.
• a metalized Mylar ring member was adhesively secured by contact cement to the uniform Mylar membrane to form a compound drumhead.
• the compound drumhead was mounted on the Ludwig tom-tom and a uniform tension applied at six points uniformly spaced around the circumference of the drum.
• the tension was adjusted to a constant value and the drum was deflected by applying an effective mass (me) so as to effect a static displacement (y) at the center of the uniform membrane.
• FIG. 8 A graph of the static deflection (y) versus the applied effective mass (m ) for the drumhead of the foregoing Example having the ring member attached and also for the uniform drumhead (i.e. the said drumhead membrane with no ring member attached) is shown in Figure 8.
• Each drumhead initially was under static tension (T ) of 468 N/m.
• T static tension
• the applied effective mass (m ). is increas ⁇ ed
• the tension is increased in both drumheads. This is indicated by the decreasing slope in each curve.
• the slope of the curve for the compound drumhead decreases more. rapidly than the slope for the plain drumhead, indicating a higher return force for the same amount of deflection. This indicates that for both membranes driven in the steady state at equal amplitudes, there is a higher return force acting in the compound drum- head hence, a larger increase in frequency is pro ⁇ cuted in the compound drumhead.
• Fig. 9 of the drawing shows the ratio squared of the large amplitude resonance frequency to the
• Figures 10 and 11 generally show the test re ⁇ sults obtained when the same compound drumhead and. uniform drumhead of Fig. 9 were subjected to the analysis as in Fig. 9 while under a tension of 468N/m and 752N/m, respectively.
• drumhead when used in conjunction with drumhead or membrane designates a drumhead or membrane having distinct portions or sections of different thick- ness and does not require that the drumhead" have two separate parts which are combined to form the dr mhead.
• drumhead of the present invention can have the ring-like section or portion secured to or extending inwardly -14- from the inner surface of the drumhead, the im ⁇ proved drumhead of the present invention can also be mounted on both ends of an open ended main body section of a drum.
• outer diameter of a drumhead membrane is referred to herein or in the claims, it should be understood that the phrase refers to the widest portion of a circular membrane extending inwardly between the supporting edges of the drumhead and does not include those portions of the drumhead membrane which are in contact with the support ring or drum body.

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• Acoustics & Sound (AREA)
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• 1980
  • 1980-09-11 WO PCT/US1980/001185 patent/WO1981003564A1/en unknown
  • 1980-09-11 EP EP81900744A patent/EP0052608A1/de not_active Withdrawn

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