Tuning device for rimless drums

A tunable shell-less, rimless drum utilizes a multiplicity of tuning assemblies positioned about the frame of a pretensioned or untensioned standard drum head. Each tuning assembly engages the frame and avoids tone impairing deformation of the drum membrane during tuning so as to preserve the natural tonal quality of the drum. A pivotably mounted lever at the bottom of the tuning assembly bears against a tuning band which engages the drum membrane, and cooperating notches on tuning band and lever retain the tuning band in a fixed position relative to the frame to prevent pitch variation or binding due to tuning band movement. A threaded rod slides along a slot in the assembly and threadably engages a lock nut positioned within a nut confinement slot to prevent unwanted loosening of the rod. The invention provides a tunable, compact, lightweight, rimless drum which has tuning convenience and tonal quality superior to most large, heavy shell type drums.

BACKGROUND OF THE INVENTION 
The invention relates to the field of tunable rimless shell-less drums and 
comprises a lightweight, compact, rimless drum which is easily, 
conveniently tuned from above without distorting its frame in a way which 
reduces its tonal quality. The invention permits the making of a truly 
compact, lightweight, tunable, rimless drum with both convenient, reliable 
tuning and tone quality so high as to be superior to most traditional 
shell drums. 
Rimless o shell-less drums are drums which can generate their sound with 
only a drum head and do not use a rim or shell to tune the head. The drum 
head consists of a membrane and a light frame which is attached to the 
membrane by adhesives or by mechanically crimping the membrane between two 
or more hoops which collectively make up the frame. The drum head may be 
wholly untensioned, or it may be slightly or wholly pretensioned during 
manufacture to have a defined pitch. Rimless or shell-less drums are 
dramatically lighter in weight and smaller in size than shell drums, but 
until the present invention could not match the tonal quality of shell 
drums and lacked a commercially accepted tuning system. 
Traditional shell drums have a cylindrical shell with a membrane, or 
"batter head", stretched over one or both open ends of the shell. The 
membrane is retained by a hoop which extends over and about the end of the 
shell. A counterhoop rests atop the hoop, and this counterhoop is engaged 
by tension rods which are positioned around the counterhoop and threaded 
into lugs which are fixed to the outside of the shell. By tightening the 
tension rods with a small drum key, the hoop and counterhoop, which 
collectively comprise a frame, are pulled down onto the shell and the 
membrane is stretched over he edge of the shell until the pitch rises to 
the desired level. These tension rods have drum key engaging heads 
positioned around the frame, and confront the seated drummer so as to be 
fully accessible and visible to him. This traditional tuning system is 
considered wholly acceptable to drummers as being fast and convenient. 
Beside the traditional tension rod tuning devices, various modifications 
and variations have been developed for shell-type drums, some of which are 
shown in U.S. Pat. Nos. 4,475,434, 3,635,119, 4,218,952, 4,211,144, 
4,295,405, 4,122,749 3,279,299, 3,029,679, 3,433,115, 2,433,200, 
2,115,741, 4,079,657, and 3,981,220. U.S. Pat. No. 3,482,479 shows a 
tuning device used with the drum head of a tambourine but accessible only 
from below and within the tambourine shell. 
Traditional shell drums are capable of excellent sound but are heavy, 
awkward to transport and cumbersome to store. A large shell drum set used 
in typical orchestral or rock bands can fill the storage capacity of an 
automobile and require multiple trips between car and stage to set up the 
instruments. The carrying of shell drums by marching bands can tire even 
the strongest drummers and limit the mobility and formations available to 
an otherwise more mobile marching unit. 
Recognizing the weight and mobility problems of shell drums, Ralph C. 
Kester, Jr., in U.S. Pat. No. 3,186,289, issued June 1, 1965, disclosed a 
more compact, somewhat lighter weight drum for marching bands which 
utilized a wide rim as a shell substitute. The drum carried a membrane and 
tuning devices on the inside of the rim. This Kester drum was more mobile 
than shell drums, but the oversize rim, to be sufficiently rigid for 
tuning purposes, was still quite heavy, the drum was expensive, and the 
tuning devices were not easily accessible or convenient to actuate. While 
the Kester device represented a positive step toward size reduction, these 
drawbacks severely limited wide commercial acceptance of his drum. 
In 1985, Kester, in U.S. Pat. No. 4,520,709, disclosed a lighter weight 
drum which had a further improved tuning system. In this drum, the tuning 
devices were placed outside the drum rim so they could now be seen by the 
seated drummer, but tuning was still awkward and done from below the drum 
by pushing the drum key upward against tension rods around the rim and 
then turning the key to force a tuning band against the membrane. During 
tuning, the key could easily slip off the rods and fall to the floor. 
Tuning was awkward, slow and hard to accomplish during performances. 
Beside being awkward, the Kester tuning structure could deform the drum 
head frame when it was tightened, and resulting binding or twisting 
deformation could reduce tonal quality. The tuning device utilized a 
bracket with a notched portion which grabbed the outer edge of the drum 
head's frame, and when the bracket was pulled down during tuning to 
stretch the membrane, the frame could be distorted downwardly and twisted 
radially inwardly. Deforming the natural circular configuration of the 
frame always affects the way the drum vibrates and reduces its tonal 
quality. When the Kester tensioning rod was tightened in the bracket, it 
could also cause camming or binding between the rod and the unthreaded 
aperture through which the rod passes, resulting in the Kester hook 30 
twisting clockwise and pulling away from the drum's center, thereby 
allowing the drum frame to be stretched into noncircular configurations 
and diminishing tonal quality. All such deformation affects the way a drum 
vibrates and changes its tonal qualities. The complex pillared frame of 
the Kester structure, while suitable for light drumming, was not designed 
to withstand heavy, rock drumming, which with its excessive vibration can 
loosen and rearrange components. The unusual design of the Kester drum 
also results in its membrane being wholly exposed to damage at the edges, 
and any striking in that region would cut the membrane. It could not be 
used for any rimshot type techniques. While lighter in weight, this second 
Kester drum design, with its complex frame, awkward tuning, exposed 
membrane and complicated assembly problems did not receive wide commercial 
acceptance. 
Any camming or distorting of the tuning devices, twisting or binding of 
frame or tuning ring, or movement of the tuning band within the frame can 
introduce deformation which significantly reduces the drum's natural, 
rich, full tones. Excessive vibration during heavy, rock-style drumming 
can produce substantial movement between drum elements, and such unwanted 
movement must be restricted if full tonal response and consistent pitch 
are to be obtained with a shell-less or rimless drum. Handling such heavy 
vibration is also challenging with marching band drums where it is normal 
practice to tightly tune the drum heads for higher frequencies which seem 
louder and project more effectively in the large stadium, noisy crowd 
situations in which marching bands perform. Obtaining the high pitch 
requires excessive tightening of tuning apparatuses and significantly 
increases the pressure applied to the drum head and the tuning device. 
When heavy drumming is done on excessively tensioned heads, the vibration 
is even more likely to cause shifting, rearrangement, and deformation of 
the tuning elements, and introduce unwanted binding and overtone 
suppression. 
As illustrated by the Kester patents, drummers have sought a compact, 
lightweight, easily transportable but finely tunable, high tonal quality 
drum, but have found it difficult to obtain both easily tunable, high 
quality sound and a compact, lightweight form. When the drum shell or rim 
is eliminated from the drum, the tuning must be done in a way that does 
not require a shell or rim. Until the present invention, no rimless or 
shell-less drum was tunable without twisting, distorting or binding the 
frame of the drum head or introducing other problems. Any such deformation 
reduced the desired depth and richness of tone which up to the present 
invention could be obtained only with traditional shell drums. 
A further step in reducing drum weight occurred with U.S. Pat. No. 
4,356,756 to Hartry et al which disclosed a new nontunable but low cost 
drum head which is known as a pretuned system head or PTS head. The PTS 
head features a membrane retained by a rigid but small, lightweight frame, 
with the membrane being tensioned chemically within the frame to provide a 
single tuned pitch level. The PTS head provided a lightweight, extremely 
compact playing surface, but its pitch could not be predicted until 
manufacture of the head was completed. 
The PTS head was made using a chemical and heating process which tensioned 
the membrane during curing to give it a pitch. Each head had to be 
individually tested after manufacture to determine its pitch, and the 
pitch continued to change throughout a sixty to ninety day curing period, 
making the final pitch difficult to predict. The heads had to be 
classified as low, medium or high pitch range, but wide variations still 
existed within the ranges. 
To speed up the production of PTS heads, a mechanical technique was 
developed in which the membrane head was mechanically crimped in its frame 
to thereby create a tensioning of the membrane. This process, described in 
U.S. Pat. No. 4,549,462 to Donald R. Hartry made the pitch of the PTS 
immediately ascertainable. This crimping process still resulted in heads 
which had a wide variation in pitch, and predictability of the pitch was 
virtually impossible. The need to test heads to classify them as low, 
medium or high continued, and there was still wide pitch variation in each 
range. Predictability was further complicated by the discovery that the 
pitch of the PTS heads was heavily dependent on ambient humidity changes 
and slightly dependent on changes in ambient temperature. These PTS heads 
were used as a substitute for standard untuned heads on traditional drum 
shells and provided a means to market a low cost drum set that required no 
tuning and appealed primarily to beginning drummers. As a result of all 
these problems, many drummers, seeking specific, consistent and 
controllable drum pitch, would not accept the untunable PTS heads. 
With the introduction of the resonance isolation mounting system shown in 
U.S. Pat. No. 4,596,176, it became possible to mount the PTS head without 
deforming its frame or significantly damping out its tonal quality. The 
combining of the resonance isolation mounting system with the PTS head 
improved the sound quality and market appeal of the head significantly and 
made it highly attractive where mobility was needed. While the tone 
quality of the PTS head was much improved by the resonance isolation 
mounting, the pitch of each PTS head remained unpredictable, varied with 
temperature and humidity, still required individual testing and 
classification and could not be tuned by drummers. 
Of the many drum tuning systems used over the years, the commercially 
successful ones are the ones that tune from above, are directly 
accessible, physically and visibly, to the drummer without any bending, 
kneeling or disassembly. Such access is crucial for fast, convenient 
tuning during performances. Musicians insist that a tuning system be 
simple to install, maintain and operate, be absolutely reliable, 
aesthetically attractive and inexpensive. The tuning system must be 
capable of holding its tune under even heavy, punishing rock concert 
conditions. It should have a minimum of parts which are not easily 
detached or lost, since it may be difficult or impossible to replace parts 
in time for a critical performance or to quickly obtain replacement parts 
from out-of-town suppliers. Until the present invention, no satisfactory 
tuning system had been found for shell-less, rimless drums or PTS heads, 
and so the weight and size advantages of rimless drums could not be 
utilized without the sacrifice of tone quality and tunability. For 
decades, these seemingly opposing requirements have been impossible to 
satisfy, and the art is a history of compromise and tradeoff between sound 
quality, bulk, weight, complexity, tuning convenience, cost and other 
characteristics. The present invention supplies a solution to these 
problems. 
SUMMARY OF THE INVENTION 
The invention comprises a tunable, rimless or shell-less drum which is 
lighter and more compact than presently known tunable drums and which has 
tonal quality exceeding most traditional shell drums. The invention uses 
either PTS drum heads or conventional, untensioned heads and permits an 
entire drum set to be stored and transported in a case no larger than that 
associated with a bass drum and effectively meets the long recognized need 
for a high tone quality, tunable drum with minimal bulk and weight. 
The tuning device utilizes a group of tuning assemblies positioned at equal 
intervals around the drum frame. A tuning band is positioned below, within 
and concentric with the frame of the drum head and against the drum 
membrane. Each tuning assembly has a cradle which retains the drum frame 
at its upper and lower edges in a way which avoids irregular stretching of 
the drum head membrane and prevents the frame from undergoing tone 
impairing deformation, such as the binding, twisting, and distortion 
caused by many prior art tuning devices. 
Positioned at the bottom of each tuning assembly is a pivotably mounted 
lever which has a front end which swings directly upward against the 
tuning band. Both the front end of the lever and the tuning band have 
cooperating, interlocking notches which, when engaged, prevent lateral or 
radial movement of the tuning band and retain it in a predetermined 
concentric position on the membrane, under even the heaviest drumming and 
vibrational conditions. 
A threaded rod passes downwardly through a socket in the tuning assembly 
and contacts the rear end of the lever to pivot the lever about its axis 
and move the front end directly against the tuning band. The threaded rod 
is provided with a drum key engaging head which directly confronts the 
drummer so as to have optimum access and visibility. All tuning operations 
can be done from above the drum while the drummer is seated in normal 
playing position. 
To assure that no loosening of the threaded rods occur during operation, a 
locking nut is positioned in a slot along the path of the threaded rod and 
securely retains the rod during operation. 
When the tuning assemblies are hooked onto the drum frame and the tuning 
band inserted in the notches of the levers, an anti-loss feature makes it 
impossible to remove the tuning assemblies from the frame. When the tuning 
assemblies are slid about the drum frame with the tuning band in place, 
neither the band nor the assemblies can be removed from the frame even 
when levers are untightened. This configuration assures that tuning device 
components, even if untightened, are not lost. 
The tuned drum is attached to a stand by a resonance isolation mounting 
system which supports the drum frame without deforming the frame or 
damping out desired resonance and overtones. 
Because, the tuning assemblies avoid tone impairing deformation the drum 
frame and prevent any unwanted movement of the tuning band even under 
heavy drumming, no substantial drum membrane distortion or binding occurs 
and a new level of tonal quality is obtained from the rimless drum. 
The pitch of the drum can be easily varied by tightening the threaded rods 
of the tuning assemblies, all such tuning and adjusting being done from 
above, with maximum visibility and convenience to the drummer. With the 
new tuning device, a lightweight, compact, up to now untunable PTS drum 
head can be used, and any pitch within the drum range obtained, with 
tuning being as easy and convenient as with traditional shell drums. 
For the first time, the invention permits the making of a truly 
lightweight, highly compact drum set which is easily carried, stored and 
maintained but which has tonal characteristics and richness of sound 
exceeding those associated with shell-type drums. The mechanical design 
permits the use of lighter weight metal or plastic materials so as to 
obtain further weight savings and is easy and economical to manufacture. 
These and other objects and advantages of the invention will appear more 
fully from the following description made in conjunction with the 
accompanying drawings wherein like reference characters refer to the same 
or similar parts throughout the several views.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to FIGS. 1 and 3, a tunable, rimless drum 10 embodying the 
invention has a drum head 12 which is supported by a drum mounting device 
such as resonance isolation drum mounting system 14 attached to a stand 16 
by any suitable means known to the art. The drum head 12 includes a 
generally annular outer supporting frame 26 which is rigidly fixed to and 
encompasses the outer periphery 13 of the drum head membrane 18 with the 
membrane having its intersection with the frame medial, and preferably 
centered, between upper and lower edges 46 and 24 of the frame. The 
membrane 18 has an obverse or batter face 28 and a reverse face 30, which 
lie substantially in a plane, and typically the membrane 18 is fixed to 
the frame 26 by an appropriate adhesive or by mechanical crimping. 
A multiplicity of tuning assemblies 20 are positioned around the outer 
periphery of the drum head 12, and each assembly engages a circular tuning 
band 22, urging it against the reverse face 30 of the membrane 18. 
The present invention is intended for use with either conventional rimless, 
non-tensioned drum heads or with the more recently developed pre-tuned 
rimless heads commercially known as PTS heads of the type shown in U.S. 
Pat. Nos. 4,416,181, 4,356,756 and 4,549,462 to Donald R. Hartry et al. 
When used with either a wholly untensioned head or with a pre-tuned head, 
the invention enables the rimless drum head to be brought to any desirable 
pitch within the range of the head. It should be understood that the 
rimless drum heads for which the present invention is designed are those 
which do not utilize any rim or shell for tuning of the head, and which 
typically consist of merely a membrane 18 and an encompassing frame 26. 
Typically, such a rimless head has the membrane 18 retained within a hoop 
32 by an adhesive interposed between the segment 32 and the reverse face 
30. A wedge 34 may be in the hoop 32, locking the membrane 18 between the 
wedge and the hoop 32. A counterhoop 36 is then applied to the top of the 
wedge 34. Mechanical crimping may be utilized to interlock the hoop 32 and 
counterhoop 36 with wedge 34 and adhesives are applied to one or both 
sides of the membrane where they join the frame 26. While a specific form 
of head 12 is shown herein as being usable with the invention, it should 
be understood that any rimless head having a membrane and an encompassing 
frame, and whether or not pre-tuned to some level, is usable with the 
invention and is within its purview. 
When the tuning device is used with a standard, untensioned drum head of 
the type used on a standard shell drum, it is necessary to use a 
counterhoop placed around the edge of the head so as to protect the edge 
of the membrane from drumstick damage and provide an edge onto which the 
upper fingers 42 of the tuning assemblies 20 can be clipped. 
With the embodiment 10 shown in FIGS. 1-5, six identical tuning assemblies 
20 are positioned about the frame 26, and as best shown in FIG. 2, each 
tuning assembly 20 includes a sturdy, substantially rigid, frame engaging 
yoke member or housing 38 which is preferably cast or stamped from an 
appropriate steel or metal alloy. The yoke member 38 has a cradle 40 which 
is constructed and arranged to closely receive the cross section of frame 
26 therein and to closely confine the frame. The cradle has an upper 
frame-engaging finger 42 and a cooperating lower frame engaging finger 44 
which respectively engage and retain the upper edge 46 and the lower edge 
24 of the frame 26. The upper finger 42 of the cradle 40 serves as a drum 
frame retention means, and the upper finger 42 and lower finger 44 
cooperate to provide a means for preventing tone impairing deformation of 
the frame 26 at its intersection with the membrane 18 by closely 
encompassing and confining the upper and lower edges of the drum frame 
cross section to prevent any substantial tone impairing irregular 
stretching of the drum membrane 18, as described below. As best shown in 
FIG. 3, concave cradle surface 48 of upper finger 42 closely engages the 
upper edge 46 and outer edge 47 of the frame. Similarly, the lower finger 
44 has a concave cradle surface 52 (FIG. 2) which closely engages the 
lower portion of inner edge 54 of the drum frame. By engaging the upper 
and lower edges 46 and 24, respectively, of the frame, any twisting forces 
which might be generated and applied to the frame during tuning are 
transferred to the frame by the assembly at the upper and lower edges 46 
and 24, resulting in the frame pivoting slightly about the frame's 
intersection with the membrane 18, with twisting of the intersection 
itself being inhibited and undergoing no substantial twisting. With the 
intersection being subjected to no substantial twisting, any irregular 
stretching of the membrane is avoided and tone impairing deformation of 
the membrane does not occur. 
As best shown in FIG. 2, the lower portion of yoke member 38 includes first 
and second bifurcations 58 and 60, respectively, which are separated by a 
straight channel 62 which extends from the front 63 to the rear 65 of the 
yoke member and angles upward as it passes the cradle 40. 
Positioned within the channel 62 is an elongated rigid lever 64 which is 
pivotably mounted on a pin 66 which is inserted along the lever axis 68 of 
transverse bore 70, which extends through bifurcations 58 and 60, with the 
pin 66 passing through an aligned aperture 72 in lever 64. A first or 
front end 74 of lever 64 has a notch 76 in upper edge 77 which, during 
operation, interlocks with one of the notches 78 in tuning band 22 as 
further described hereafter. Front end 74 of the lever joins gently curved 
bottom edge 83, which terminates at rear or second end 82 of the lever. 
The edge 83 is curved to facilitate easy handling and to avoid damage to 
adjacent, nested drum heads in the event heads are stacked or nested 
during storage and transport. The front end 74 of the lever extends 
forwardly and beyond front surface 63 of the yoke member so as to firmly 
engage the tuning band 22 and urge the band directly upward in a direction 
substantially perpendicular to membrane 18 and parallel to tuning band 
axis 114. 
As best shown in FIGS. 2-4, a socket 86 extends from the upper surface 88 
downwardly to intersect and communicate with the roof 61 of channel 62. 
The socket 86 has a central axis 98 and is of a diameter greater than the 
greatest thickness of the shaft 90 of threaded rod 92, permitting the 
shaft 90 to slide freely in the socket 86. The socket has a recess 95 
surrounding the upper end of the socket so that when the rod head 94 is 
below the level of upper surface 88, a standard drum key 136 can be 
received on the head. 
Positioned along the axis 98 of socket 86 is a nut confinement slot 100 
which has a rear wall 102 which bears firmly against a side 104 of lock 
nut 106, when the nut is in slot 100 with the nut axis 108 coinciding with 
socket axis 98. By such positioning, the side 104 which is in close 
engagement with rear wall 102, is prevented from rotating about axis 108 
when the threads of rod 92 are engaged with the nut 106. The slot 100 and 
nut 106 provide a rod retention means to allow the rod to be threaded 
toward the lever 64 as needed. As best shown in FIG. 3, the rod 92 is 
threaded into and through lock nut 106 with the threads of the rod passing 
through and engaging an internal friction lock washer insert 110, which 
serves as a locking means to prevent unwanted slippage or rotation of the 
rod during heavy drum vibration. The rod 92 is threaded through the nut 
106 until its lower end contacts the upper edge 112 of lever 64. By 
additional advancement of the rod 92 toward rear end 82 of lever 64, the 
lever's front end 74 is urged upwardly against notch 78 of the tuning band 
22. 
The rod 92 is preferably formed from a shortened, commercially available 
drum tension rod of the type found on most shell drums. 
The tuning band 22 is generally circular and is formed with a rounded upper 
bearing edge 116 to assure a smooth contact surface with membrane 18. 
Spaced around the periphery of the band's lower edge 118 are a 
multiplicity of tuning band notches 78, here shown as six such notches, 
all equally spaced. 
The tuning band 22 is formed of a generally rigid material such as metal or 
plastic and has a diameter slightly smaller than the internal diameter of 
the drum frame 26. The tuning band is substantially concentric with the 
frame 26 of the drum. The notches 78 in the tuning band are positioned to 
closely confront the corresponding notches 76 of the levers 64 of each 
tuning assembly, and when the tuning assemblies are in operating position 
and engaging the drum frame 26, the levers are forced upwardly to cause 
the notches 76 and 78 to interlock. This interlocking action of vertical 
abutments 81 at the sides of each notch 76 and 78 assures that the tuning 
band stays substantially concentric within the drum frame and, as shown in 
FIG. 2, prevents unwanted movement of the tuning band in radial directions 
121 and lateral or tangential directions 120 under the heaviest of 
drumming conditions. 
As best shown in FIG. 3, when notch 76 of lever 64 is urged upward in 
direction 84 and contacts the tuning band 22, the upper edge 77 of the 
lever is generally parallel to the plane of the membrane 18, and the force 
applied by the lever against the tuning band 22 is substantially 
perpendicular to the plane of the membrane and parallel to axis 114. By 
applying this force parallel to the tuning band axis and at a multiplicity 
of equally spaced locations 78, the tuning band does not tend to bend, 
distort, or twist from its generally circular configuration, and all the 
forces applied by the tuning assemblies 20 move the tuning band directly 
perpendicularly against the membrane 18. Because of the perpendicularly 
directed force, the interlocking notches 76 and 78, and the resulting 
absence of significant binding, distortion, or twisting, the tuning band 
80 can be less massive than was formerly the case, shorter from top to 
bottom, and can also be thinner from inside to outside, thereby 
significantly reducing the weight of the band 22. In addition, because of 
the interaction of the interlocking notches and the perpendicularly 
directed forces, the material for the tuning band need no longer be formed 
of a steel or steel alloy and can, instead, be formed of lighter materials 
such as aluminum or an appropriate plastic. 
It should be understood that the number of tuning assemblies positioned 
about the frame of the drum will vary with the size of the drum. It has 
been found that at least four tuning assemblies should be used to obtain 
acceptable results, although six or more assemblies are preferred and 
produce more uniform pressure between tuning band and membrane and less 
deforming of the frame. For drum heads having ten, twelve, or fourteen 
inch diameters, six tuning assemblies 20 provide excellent results. For 
drums heads having sixteen or twenty inch diameters, six to eight 
assemblies are needed, and eight are preferred. 
While the tuning device has been shown as usable on a circular drum head, 
it should be understood that other drum head configurations such as oval, 
triangular, square and the like may also be tuned using the invention. In 
such situations, the tuning band should have a configuration like that of 
the drum frame, as for example a triangular tuning band for a triangular 
drum. Tuning assemblies should be positioned at equal intervals around the 
band and in some cases at corners of the band. 
It is desirable that the tunable, rimless drum 10 be mounted to stand 16 in 
a manner which does not damp out or attenuate the natural frequencies and 
tonal quality of the instrument. This goal can be achieved by supporting 
the drum head 12 with a resonance isolation mounting system 14 of the type 
shown in U.S. Pat. No. 4,596,176. Such a mounting system utilizes an 
arcuate member 124 to which are mounted a plurality of flexible, rubber, 
frame supporting fingers 126, which engage the frame 26 of the drum head 
12 in a vibration isolating manner which does not attenuate the natural 
tones. When the resonance isolation mounting system 14 is interposed 
between the frame 26 and stand 16, frame deformation is avoided and the 
full tonal qualities of the drum 10 come through to the listener. 
OPERATION OF THE INVENTION 
In operation, the drummer first adjusts the tuning assemblies 20 so the 
levers 64 will have their front ends 74 inclined downwardly to a lever 
position 128 (FIG. 6). He next attaches an appropriate number of the 
tuning assemblies 20 onto the frame 26 of the drum head 12 by first 
hooking the concave surface 52 of the lower finger 44 of each assembly 
onto the lower edge 24 of the frame and then, with bottom 24 bearing 
against the finger surface 52 (FIG. 6), swinging the closely fitting upper 
finger 42 over and onto the upper edge 46 of the frame. These steps place 
the frame in cradle 40 with a gap between upper finger surface 48 and 
upper edge 46. During the initial steps just described, the tuning band 22 
is not yet installed, and all of the tuning assemblies are next slid along 
the frame 26 so they are closely grouped as shown in FIG. 5. With the 
assemblies thus grouped and with their levers in positions 128, the tuning 
band 22 is next positioned within the drum head 12 by slipping its bottom 
118 within the notches 76 of the levers of all of the tuning assemblies, 
as shown in FIG. 6, and next swinging the tuning band toward membrane 18 
to a position 130, shown in FIG. 3, with the band upper edge 116 in full 
contact with the reverse face 30 of the membrane. In this position 130, 
the lower edge 118 of the tuning band 22 forces the tuning assemblies to 
shift downward to position 134 (FIG. 3) Where the upper edge 46 of the 
frame 26 is in direct, full contact with surface 48 of finger 42. This 
movement creates a gap between the lower edge 24 of the frame and surface 
52 of lower finger 44 (FIG. 3). So long as the tuning band is between the 
membrane 18 and levers 64, the cooperating fingers of the grouped tuning 
assemblies prevent the assemblies from being removed from the frame 26. 
The operator next slides the individual tuning assemblies 20 to equally 
spaced positions around the frame 26 with the tuning assemblies being 
arranged so the lever 64 of each assembly underlies and confronts a tuning 
band notch 78 such that the individual notches 76 and 78 of each lever and 
tuning band, respectively, can engage and interlock. As soon as the tuning 
assemblies are moved from the grouped arrangement of FIG. 5 to an equally 
spaced position, the tuning band 22 can no longer be removed from within 
the drum head 12. As described above, the tuning band 22 cooperates with 
the assemblies and the frame to lock the assemblies in place on the frame, 
even if the levers are not tightly engaging the band. This anti-loss 
feature assures that the assemblies are not separated from the drum frame 
or lost during travel. This result is highly desirable because it assures 
that during use or transport of the drum, it is impossible to lose the 
tuning assemblies or tuning band, even if the assemblies or band are 
untightened. In order to remove the band 22 and the individual assemblies 
20, the operator must reverse the installation procedure by moving all of 
the tuning assemblies back to the group position of FIG. 5 and then swing 
the band 22 outwardly and away from the reverse face 30 of the membrane 
18. 
When the tuning assemblies 20 have been positioned around the frame of the 
drum, with the notch 76 of each lever 64 confronting a notch 78 of the 
tuning band, the operator next tightens the threaded rod 92 by applying 
key 136 to the head 94 of each rod to rotate the threaded rods downward in 
socket 86 until the notch 76 of each individual lever 64 interlocks with 
the confronted notch 78 on the tuning band. When interlock occurs, all 
tuning assemblies are securely, tightly in place and can no longer slide 
in directions 120 along the frame 26. Tuning of the membrane 18 can now 
begin. 
The operator now alternately tightens each threaded rod 92 a little at a 
time, tightening the rods of each successive assembly a substantially 
equal amount, until the desired drum pitch has been obtained. The tuning 
is easy because the operator has visual contact with each rod head 94 and 
with each tuning assembly while seated in a normal drumming position. All 
drum key adjustments to the assemblies are done from above the drum, 
thereby avoiding any bending or kneeling by the operator and eliminating 
the need to do any adjusting from beneath the drum head. 
As the drummer turns the threaded rods 92 in a clockwise direction about 
the axis 98, each rod moves downwardly, turning freely in socket 86 but 
threadably advancing through the threaded lock nut 106 so that the rod end 
110 pushes the rear end 112 of lever 64 downwardly in direction 138 to 
pivot it about pin 66. During rod rotation, lock nut 106 has its side 104 
bearing against side 102 within slot 100 so as to prevent the nut 106 from 
turning and allowing rod rotation only when key 136 is used. As the end 82 
of the lever is pushed downwardly, the front end 74 of the lever moves in 
direction 84 substantially parallel to the axis 114 of the tuning band 22, 
thereby engaging and urging the tuning band 80 directly against the 
membrane without twisting or distorting the band or creating any binding 
of the membrane or frame. As the band 22 is pressed against the membrane, 
the membrane is gradually stretched and tensioned and its pitch rises. 
Because during tuning each of the levers 64 has its upper edge 112 
generally parallel to the membrane 18, the downward force of the threaded 
rod 92 results in a force being exerted in a direction 84 which is 
generally perpendicular to the plane defined by the lower edge 118 of the 
band 22. 
The interlocking of notches 76 and 78 assures that each tuning assembly 
cannot slide in directions 120 along the tuning band because its lever 64 
is closely constrained by the abutments 81 at each edge of the tuning band 
notch 78. Similarly, the interlocking of the notches 76 and 78 and 
presence of the abutments 81 on the lever notch 76 prevent the tuning band 
from moving radially in directions 121 toward or away from the frame 26 of 
the drum. This interlocking of the notches 76 and 78 assures that the 
tuning band 22 stays largely concentric with the frame 26 and that the 
tuning assemblies 20 stay in the intended positions where they are equally 
spaced around the band. Such constraint is desirable because if the band 
shifts to be nearer the frame at some point, the band may apply more 
leverage to the membrane at that point. This will stretch the membrane 
more than necessary at that point and also twist or deform the frame at 
that point. Such stretching or twisting would be detrimental to the drum's 
tonal quality. 
The lock nut 106 and its locking insert 110 assure that when the tuning rod 
92 has been tightened to a desired level, it does not loosen in nut 106, 
even under the heaviest drumming conditions. 
The locking between the tuning assemblies 20 and the band 22, and the close 
engagement between each tuning assembly and the frame, provide a tight, 
rigid interlocking arrangement between band, tuning assemblies and the 
frame itself and prevent the intersection between frame and membrane from 
twisting, or being otherwise deformed from its natural configuration 
during tuning and operation. By thus preventing irregular stretching of 
the membrane during tuning and operation, the tonal quality of the drum is 
maintained at its highest level. 
The tunable drum 10 may be equipped with an electronic trigger or 
detonator, if desired, so as to use the drum to trigger electrically 
simulated tones or special light or sound effects. Such a detonator is 
preferably a type which serves as a combined microphone and trigger so the 
acoustic tones of the drum may be picked up and amplified when desired. 
While the preferred embodiment of the present invention has been described, 
it should be understood that various changes, adaptations and 
modifications may be made therein without departing from the spirit of the 
invention and the scope of the appended claims.