WO2017091158A1

WO2017091158A1 - System for tensioning and quick replacement of drum membrane, its components, drum with the system, and method of tensioning and rapid replacement of drum membrane

Info

Publication number: WO2017091158A1
Application number: PCT/SI2016/000027
Authority: WO
Inventors: Matija ŠMALCELJ
Original assignee: MANIC DRUM d.o.o.
Priority date: 2015-11-23
Filing date: 2016-11-22
Publication date: 2017-06-01
Also published as: SI25098A

Abstract

The subject invention discloses a new system for the tensioning and quick replacement of membrane (9) of the drum, consisting of a tensioning rim (4), which has around the circumference evenly distributed clamping lugs (41), tensioners (6, 60), base shell of the drum (2), the resonance rim consisting of equal or different segments (3, 33), where the membrane tensioners (6) are fastened to the base shell of the drum (2) by means of screw joints (80), and where the membrane (9) with hoop-shaped frame is placed on the base shell of the drum (2), wherein on the said hoop-shaped frame is laid the tensioning rim (4) so that the axis of each fastening lug (41) coincides with the vertical axis of the corresponding membrane tensioner (6). The invention further discloses the new tensioner (6, 60) of the membrane (9), as well as a method of tensioning and rapid replacement of the membrane (9) of the drum.

Description

SYSTEM FOR TENSIONING AND QUICK REPLACEMENT OF DRUM MEMBRANE, ITS COMPONENTS, DRUM WITH THE SYSTEM, AND METHOD OF TENSIONING

AND RAPID REPLACEMENT OF DRUM MEMBRANE

Field of invention

Respective invention belongs to the field of musical instruments, and more specifically to the field of the drums.

Subject of invention

The subject of invention is a new system for tensioning and quick replacement of drum membrane, its components, as well as a drum with a new system, and method of tensioning and rapid replacement of drum membrane.

State of the art

In the art, namely in the field of musical instruments, are known various types of drums, but which are in their essential characteristics similar to each other. Drum is a percussion instrument, in which a sound is produced by the membrane. Membranes were once made from animal skins, nowadays are made mainly of synthetic materials. A base shell of a drum is essentially a tube, or rather a hollow cylindrical body having two, normally parallel, base surfaces or rather parallel base edges, on which are mounted and tensioned membranes. With the beating on the tensioned membrane, a user produces a sound, which frequency or tone depend on the tension level of the membrane.

A specific type of drum, known in the art as »side drum« or »snare drum« has the lower membrane, called a resonance membrane and underneath it, the snares are stretched, which produce the characteristic noise.

The use of the drum, tensioning the membrane or the manipulation of the drum, cause also the wear or damage of the membrane. A drum with the damaged membrane is unserviceable, so the only solution is a replacement of the membrane. Technical problem

By state of the art, the drums have the membrane attached to the body of the drum with a retaining rim with equally spaced holes around the circumference, through which the tension rods are pushed and screwed into a corresponding lugs attached at the outer shell of the body of the drum. The rims have a different number of holes, which is usually between 4 and 12.

For replacing the membrane, the user must unscrew all, so at least four tension rods, pull them out of the rim, remove the rim, replace the membrane, install the rim and tighten again all the tension rods, and then also tune the membrane, by adjusting the tightness of the tension rods.

The replacement of the membrane should often be performed in the studio, just before or even during the concert, which is by the current method almost impossible, because it requires too much time. The time required for the replacement of one membrane by method described above is namely between 5 and 20 minutes.

The technical problem with which the subject invention deals is a system that allows quick and easy replacement of the membrane of the drum, as well as its tuning.

Short description of the invention

The subject invention solves the described technical problem by introducing a system for tensioning the drum membrane, which allows extremely quick replacement of the membrane of the drum, as well as its tuning.

Short description of the figures

In the following, the subject of invention is described with reference to the accompanying figures representing:

Figure 1 : a drum with a new system for tensioning the membrane of the drum, in exploded view,

Figure 2 A: detailed view of the clamping point of the tensioning rim,

Figure 2B: a drum with a new system for tensioning the membrane of the drum, in assembled view, Figure 2C: the basic shell of the drum in vertical section, with a tensioner base,

Figure 3A: segment of a resonance rim in the first version,

Figure 3B: segment of a resonance rim in the second version,

Figure 4: tensioning rim,

Figure 5A: view of the bolt connection of the rim and segment,

Figure 5B: composition of tensioning rim and resonance rim of bass drum,

Figure 5C: installation of the carrier plate for bass drum pedal,

Figure 6A: membrane tensioner in exploded view, first version,

Figure 6B: base of the tensioner shown on the Figure 6 A, front view,

Figure 6C: base of the tensioner shown on the Figure 6 A, back view,

Figure 6D: membrane tensioner from Figure 6 A in assembled view, front view,

Figure 6E: membrane tensioner from Figure 6 A in assembled view, back view,

Figure 6F: membrane tensioner in assembled view, front view, second version,

Figure 6G: membrane tensioner shown on the Figure 6F, back view,

Figure 6H: base of the membrane tensioner shown on the Figure 6F, front view,

Figure 61: base of the membrane tensioner shown on the Figure 6F, back view,

Figure 7: a drum with state-of-the-art drum membrane tensioning system,

Description of state-of-the-art drum head tensioning system

Figure 7 shows a drum 70, in this case. »snare drum«, with the state-of-the-art system for the tensioning of the heads 71 A and 71B of the drum 70. The drum 70 consists of a base upright cylindrical shell 72, which has two parallel base surfaces on which they are installed and tensioned upper head 71A and lower head 71 B. Heads, which as the drum elements can be purchased by over-the-counter transaction, consist of a membrane fixedly positioned on the hoop-shaped subframe, which inner diameter loosely fit to the external diameter of the base shell 72 of the drum 70.

The membranes 71 A and 71 B are pressed on the basic shell 72 of the drum 70 by the rims 73A and 73B, which have lugs with holes 731 evenly distributed around the circumference. Along the circumference of the base shell 72 are fixed nuts 74, which have the same distribution as the lugs on the rim. Through the said holes 731 are vertically, up or down inserted rods 732, with washers 733, which are screwed into the corresponding nuts 74.

In this way, the hoop-shaped frames of the membranes 71 A and 71 B are pushed to the base shell 72 of the drum 70. By screwing the rods 732, the membranes 71 A and 71 B are tensioned and the drum can be tuned to the desired frequency or tone with changing the degree of tension of the membrane.

The described system for tensioning the membranes 71 A and 71B is basically the same regardless of the material of the membrane.

Figure 7 shows also the clip 75 for tensioning the snares under the lower membrane 7 IB. Since the snares should be in contact with the lower membrane 7 IB, the bottom rim 73B must have two diametrical slots for the band or cord for tensioning the snares. Consequently, the hoops 73A and 73B of »snare drum« are not equal.

When replacing the heads 71 A and 71B it is necessary to unscrew and remove all the rods 732 tensioning the membrane, which we want to replace, and then to remove the rim 73A or 73B, replace the membrane and repeat the procedure in the opposite direction, followed by tuning the drum 70.

Detailed description of the invention

The subject invention solves the described technical problem by introducing a system for tensioning the drum membrane, as described below by using the implementation example shown in the attached figures.

In the following the subject invention is described by using the implementation example for the snare drum, but the system is substantially the same for all sizes and types of drums. The only difference is in the bass drum, where the resonance rim assumes the role of the carrying or supporting rim for the plate on which it is fixed the pedal, by which the drummer moves with the leg the rod, which beats against the membrane of the drum.

Figure 1 shows the drum 1 with a system for tensioning the membrane of the drum according to the subject invention. The shown drum 1 consists of a base drum shell 2 with the holes 21 for mounting the membrane tensioners 6, distributed around its outer circumference. As shown in Figure 2C the upper and lower edge 22 of the basic shell of the drum 2 are chamfered so that the contact surface of the membrane 9 on the drum shell

2 is as small as possible, which provides improved vibration of the membrane.

On the base shell 2 of the drum 1 is loosely laid the membrane on the hoop-shaped frame

9, the tensioning rim 4 is laid on the hoop-shaped frame so that the axis of each clamping lug 41 is even with the vertical axis of the corresponding membrane tensioner 6. On the tensioning rim 4 are optionally attached the segments of the resonance rim 3.

The shown drum 1 has the same sequence of elements on the lower side, with the difference that between the tensioning rim 4 and the optional segments of the resonance rim are snares 7A, which are on one side attached to the shell 2 of the drum 1 , on the other side clamped by the tensioner 7B.

Attaching and tensioning of the snares is in the art well known, so it is not described more in detail. An essential innovation of the system according to the subject invention, in terms of snares 7A, is in that it is routed through the gap between the tensioning rim 4 and the segments of the resonance rim 3.

In the shown example, the membrane 9 is clamped to the base shell 2 of the drum 1 by means of ten membrane tensioners 6, which are evenly distributed and attached to the circumference of the drum, in the case under consideration, therefore, in the mutual angular distance of 36 °. The number N of tensioners 6 for the tensioning of one membrane 9 depends on the type of the drum. In the shown implementation example it is about a snare drum, where the nominal diameter of the membrane 9 is 14 inches (about 355 mm). Number of tensioners 6 can be adapted to the client's wishes, and usually ranges between 4 and 12, but of course it can also be of smaller and especially of a greater number.

The tensioning rim

In Figure 4 is shown a tensioning rim 4 which is flat and has an internal radius Rl and an external radius R2. The rim 4 has on its outer circumference a number N of equal clamping flat lugs 41 , which extend radially from the outer radius of the rim 4 to the radius R 3. In the shown example, the number of lugs 41 is ten, at a mutual angular distance of 36 °. The clamping lug 41 consists of two flat, across the radius mutually symmetric, side protrusions 41 A, through which are axially made the holes 41B of a diameter Dl , which are located at mutual axial distance XI and mutual angular distance al and whose centres are located on a circle with radius Rvl . Between the said side protrusions 41A is a slot 41C with a narrowed opening 41 D. The centres of the nearest holes 41B of two adjacent lugs 41 are located at a mutual angular distance βΐ .

The said mutual axial distance XI between holes 41 B is substantially the same, regardless of the nominal diameter of the membrane 9 and is between 22 and 28 mm, in the preferred implementation, the axial distance XI is 25 mm. Angular distance al between holes 41 B depends on the nominal diameter of the membrane 9, and in the case under consideration amounts to approximately 7°, considering the fact that the axial distance XI does not change with the diameter of the membrane 9, it is clear that the angular distance al decreases with increasing the nominal diameter of the membrane 9, and vice versa.

The inner radius Rl of the tensioning rim 4 depends on the nominal diameter of the membrane 6 and in the case under consideration amounts to approximately 180 mm. The outer radius R2 is in the shown implementation example greater by about 7 mm from the inner radius Rl , the radius of RV1 is greater by about 10 mm from the inner radius Rl , the radius R3 is greater by about 18 mm from the inner radius Rl .

The thickness of the described tensioning rim 4 in the shown implementation example is approximately 4 mm, but may be larger or smaller, depending on the required tensioning force.

The tensioning rim is made of a suitable metal, preferably stainless steel, but may also be made of wood or synthetic materials with the appropriate strength properties.

The segment of a resonance rim

Figure 3 shows a segment of the resonance rim 3, which describes an arc of the angle δ and has an inner radius R4 and the outer radius R5. On the outer circumference of the segment 3 are distributed four equal, across the radius symmetrical flat clamping lugs 31 which extend radially from the outer radius of the segment 3 to the radius R6, where they are roundly terminated. Through the said lugs 31 are made in the axial direction the holes 32 with the diameter D2, the centres of which are located on the circle with a radius Rv2. The angular distance between the centres of the holes 32 of two mutually closest lugs 31 is α2, their mutual axial distance is X2. The angular distance between the centre of the hole 32 of any extreme lug 31 and the centre of the hole 32 of its nearest lug 31 is β2. The said angle a2 of segment 3 is equal to the angle al of the tensioning rim 4, the said angle β2 of segment 3 is equal to the angle βΐ of the tensioning rim 4, and likewise the axial distance X2 is equal to axial distance XI between holes 41 B of the lug 41 of the tensioning rim 4. Radius Rv2 of the segment 3 is equal to the radius Rvl of the tensioning rim 4. Diameter D2 of the holes 32 of the lugs 31 of the segment 3 is greater than the diameter Dl of holes 4 IB of the tensioning rim 4.

From the above it follows that the sum of the angles al and βΐ of the rim 4 is equal to the sum of the angles a2 and β2 of the segment 3, namely, the said sum depends on the number N (hereinafter referred to as division), representing the number of tensioning clamps 5 and, consequently, the clamping lugs 41 of the rim 3 and amounts to 360°/N. As described above, the axial distance XI which is equal to the axial distance X2, is essentially the same, regardless of the nominal diameter of the membrane 9 and is between 22 and 28 mm, in the preferred implementation, the axial distance XI is 25 mm. The said sum of the angles al and βΐ or α2 and β2 defines division of attachment points and their angular distance which in the described implementation example amounts to 36°.

The said angle δ of segment 3 is less than two divisions, that is, in the described implementation example amounts less than 72°.

The thickness of the described segment 3 in the shown implementation example is approximately 4 mm.

The inner radius R4 of the segment 3 is the preferred implementation smaller than the inner radius Rl of the rim 4 and in the described implementation example amounts to 350 mm, the outer radius R5 of the segment 3 is greater by approximately 10 mm from the inner radius R4, and the radius R6 is greater by approximately 22 mm from the inner radius R4. As stated above, the radius Rv2 of the segment 3 is equal to radius Rvl of the tensioning rim 4.

In the described implementation example, the resonance rim consists of five identical segments 3. The implementation of the resonance rim with an arbitrary number of segments, which may be mutually different, depending on the wishes of the user, is also possible.

Figure 3B shows another version of a resonance rim segment 33 extended by one division, which in the described implementation example amounts to 36°. All radii RV2, R4, R5 and R6 are the same as for segment 3, the same are also the flat clamping lugs 31 , the corners a2 and β2, as well as the axial distance X2. From the above it follows that the angle 82 of the segment 33 is greater than the angle δ of the segment 3, namely for one division. Therefore 62 = δ + 36°. In described manner, it is possible to prolong the segment of the resonance rim for an arbitrary number of divisions.

In described manner, the segment 3 of the resonance rim can be shortened by one division, or prolonged by one, two or three divisions. In a preferred implementation the segment of the resonance rim 3 is not shorter than shown in Figure 3 A.

Description of the joint between resonance segment and hoop, and method of assembly

The joint between the resonance segment 3 and the hoop 4 is shown in Figure 5 A and consists of the spacer 10A, the threaded sleeve 10B, the bolt IOC, the spring washer 10D, and the spacer 10E. As shown in Figure 5 A, the resonance segment 3 is placed on the hoop 4 so that all the holes 32 of the resonance segment 3 are placed coaxially over the positionally corresponding holes 41B of the tensioning rim 4. The mutual distance between the upper surface of the tensioning rim 4 and the lower surface of the segments of the resonance rim 3, which is determined by the length of the spacer 10A, is between 8 and 15 mm, in a preferred implementation between 10 and 13 mm.

Between the hoop and the resonance segment at the points of the holes 32 and 4 I B, we coaxially insert spacers 10A and then we insert from the upper side in the hole 32 of the segment 3 the threaded sleeve 10B. From the lower side we insert the bolt IOC with the spring washer 10D and the spacer 10E in the hole 41B of the hoop 4. We screw the bolt IOC with the thread corresponding to the thread of the threaded sleeve 10B into the threaded sleeve 10B. When the bolt IOC is screwed, there is still about 2 mm empty space to the upper end of the threaded sleeve 10B. The said bolt IOC, spring washer 10D and threaded sleeve 10B are standard components, which can be purchased by over-the-counter transaction. All the above elements are in the preferred implementation made of stainless steel, but they can also be made of synthetic materials, with appropriate strength properties.

By mounting the five resonance segments 3 on the hoop 4 in described manner, we obtain the assembly of the resonance rim consisting of five resonance segments 3, which are mutually laterally without contact, and the tensioning rim 4.

The mounting of the segment 33 on the hoop 4 is carried out in the same way. As mentioned, the implementation of the resonance rim with an arbitrary number of segments, which may be mutually different, is also possible. Thus, the resonance rim can be assembled, for example, from two segments 3 and two segments 33, which can be arbitrarily arranged over the tensioning rim 4. The distance between the sides of two adjacent segments 3 or 33 is at least 2 mm.

For the bass drum, standing or lying on the ground the user pushes with the foot the pedal, which moves the rod that beats on the membrane. In this case, it is not necessary that the resonance rim is composed of segments, as the resonance rim assumes the role of the carrying rim 30A or supporting rim 3A for carrier plate 3C, on which we fasten the pedal. The bass drum has the supporting rim 3A on the side where the pedal is installed, and on the other side the carrying rim 3 OA.

As shown in Figure 5B, at the side where it is mounted the pedal, the tensioning rim 4A is used which is in all the elements the same as the clamping rim 4 described above, except that has in the middle between two adjacent clamping lugs 41 the hole 49, on which it is attached the supporting rim 3A, which is made in one piece and which is at the place 3B interrupted. At the place of interruption 3B is into the gap inserted and attached the carrier plate 3C, to which it is then attached the bass drum pedal (not shown).

On the opposite side of the bass drum, the tensioning rim 4 as described above is used, to which it is attached the carrying rim 30A that is in all the elements the same as the supporting rim 3A but without the interruption and therefore runs continuously around the entire circumference.

The method of attachment of the plate 3C to the rims 4 and 3A is clearly shown in Figure 5C. The plate 3C is attached to the rim 3A with two screws 50A, to the rim 4 with one screw 50, where it is important that the screw 50 have a countersunk head and the hole 49 adequately chamfered edge and after assembly the screw does not protrude out of the rim 4.

In other details the rims 3A and 30A are the same as the segments of the resonance rim 3 and 33 described above. The joints of the rims 4 and 4A and the rims 3 A and 30A are the same as the joints of the rim 4 and the segments of the resonance rims 3 and 33 described above.

In the assembled state, the spacers 10E and the screw heads 10C, constituting the centring points when the assembly of the hoop 4 and the segments 3, 33, 3 A are placed on the membrane 9, previously deposited on the base shell of the drum 2, protrude from the bottom of the composition of the rim 4 and the rim 3, 33, 3 A.

Description of the membrane tensioner

The first version of the membrane tensioner 6 is shown in exploded view in the Figure 6A. The tensioner 6 consists of the base 61, the tensioning handle 62, two levers 63, the lower pin 67 with corresponding snap rings 67A, the middle pin 66 with corresponding snap rings 66A, the tension rod 64 with the washer 64A and the upper pin 65 with corresponding snap rings 65A where through the pin 65 perpendicular to its longitudinal axis is the hole 65B with thread into which fits the tension rod 64.

Figure 6 clearly illustrates how the listed parts of the tensioner are assembled, first we put together the base 61 and handle 62 by using the middle pin 66, where the pin 66 passes through the openings 62A in the handle 62 and then we place on the pin 66 appurtenant snap rings 66A. Then, we put on both ends of the upper pin 65 the upper part of the levers 63 and we place on the upper pin 65 the appurtenant snap rings 65A. We place thus assembled levers 63 and the pin 65 on the upper groove 61C of the base 61 and we put at both ends of the lower pin 67 the lower part of the levers 63, and we place on the pin the appurtenant snap rings 67A. The lower pin must pass through the lower groove 62B of lever 62 and through lower opening 61 A of the base 61. Then, we screw in a hole with thread 65B of the upper pin 65 the rod 64 with the washer 64A. The combination of the pin 65 and a transverse threaded hole 65B allows a circular movement of the rod 64 about the axis of the pin 65.

With this the tensioner is assembled. The handle 62 is against the base 61 rotatable around a central bolt 66. The levers 63, which are at the top connected with the upper pin 65, and below with the lower pin 67 are parts of a mechanism for tensioning. Due to the fact that the pins 65 and 67 are not fixedly clamped, but move freely in the cradles, the entire tensioning mechanism of the tensioner 6 has a guaranteed room for mounting and tensioning system for tensioning the membrane of the drum, as well as for the tuning of the drum.

In Figures 6B and 6C is shown the base 61 , where it is more clearly shown the lower opening 61 A of the base 61. As described above, through this opening passes the lower pin 67. When the tensioner 6 is in the open or detached state, the pin is located in the upper part 61 D of the opening 61 A. When we push the handle 62 of the tensioner 6 toward the base 61, the handle 62 is rotated around the central pin 66, lower pin 67 travels down to the toothed part 61E of opening 61 A. Figure 6B shows the toothing, allowing the three positions of the tensioner 6, and thus three degrees of tension of the membrane 9, which is most tensioned when the bottom pin 67 is located in a position that is the farthest from the upper part 6 ID of the opening 61 A. The base 61 has at the bottom two holes 61B for the fastening on the base shell of the drum 2.

Figures 6D and 6F clearly show assembled tensioner 6.

The rod 64 and snap rings 65A, 66A, 67A are standard elements, as well as pins 66, 67 and can be purchased by over-the-counter transaction and are well known in the art. All the mentioned pins have at the ends grooves into which fit the appurtenant snap rings. In the described implementation example, the rod with the square head and collar, M6 dimension and a suitable length, which is in the preferred implementation between 40 and 100 mm, is used. All the parts of the described membrane tensioner 6, with the exception of the washer 64A, which is made of plastic, and snap rings 65 A, 66A, 67A are made of metal, in the preferred implementation of stainless steel, but they can be also made of synthetic materials, with appropriate strength properties.

The second version of the membrane tensioner 60 is shown in assembled view in the Figures 6F and 6G.

The tensioner 60 consists of a base 610, which is essentially double base 61 of the tensioner 6 in the first implementation. On the base 610 are mounted the identical elements as are mounted on the base 61 in the description above, except that two tensioners that face each in its own direction are mounted on one base.

The base 610 which is more detailed shown in Figures 6H and 61 has on the back side three holes 610B for installing the tensioner 60 to the base shell of the drum 2. The number of attachment holes of 610B is from 2 to 4, in the preferred implementation, the base 610 has three holes 610B. With the tensioner 60 we can mutually independently tension both membrane 9 of drum 1. The base 610 has a double toothing 610E, 61 OF, which allows several mutually independent tension levels of each of the membrane 9.

The membrane tensioner 6 is in the base shell of the drum 2 attached with the base, where through a respective hole 21 (the upper two holes or bottom two holes in the base shell of the drum 2, which are located one above the other) and the hole 61 B in the base 61 is screw joint 80 wherein each screw joint 80 consists of threaded sleeve 10B that is the same as above already said threaded sleeve 10B, the screw 10F, spring washer 10D (which is the same as above) and the wide washer 10G.

Figure 2B schematically shows the mounting of the base 61 of the tensioner 6 to the basic shell of the drum 2. All the listed elements of the screw joint 80 are standard and in a preferred implementation made of stainless steel.

In the case of the use of the tensioner 60 are on the main shell of the drum vertically arranged only three holes, at the same distance as the holes 610B at the base 610.

In the above-described implementation are used the standard Allen screws M5 of suitable length, suitable washers and said threaded sleeves 10B, which are the so-called expansible nuts M5 with a flat head and knurled neck with length of approx. 14 mm. Such screw joints are known in the art and therefore are not described more in detail.

The composition of the drum with the system of membrane tensioning according to the subject invention

The first assembly

The membrane tensioners 6, 60 are attached to the outer circumference of the base shell of the drum 2. The order of attachment of tensioners 6 is shown in Figure 2 A, in the case of using tensioners 60, the distribution of attachment is analogous.

We push the handles 62 of the tensioners 6, 60 in the radial direction in the extreme open position, and tilt outwards the rods 64 which are screwed into the threaded holes 65B of pins 65.

We put the membrane 9 on the subframe on the upper edge 22 of the base shell of the drum 2 so that the membrane 9 sits on the edge 22 and the subframe loosely fits to the outer diameter of the base shell of the drum 2. We place the tensioning rim 4 or composition of tensioning rim 4 and resonance rim 3 or composition of tensioning rim 4 A and resonance rim 3 A (hereinafter: composite hoop) on the subframe of the membrane 9 so that the tensioning rim 4, 4 A sits on the subframe of the membrane 9. At the same, the spacers 10E and the screw heads 10C embrace and centre the said assembly with respect to the sub-frame of the membrane 9 and prevent incorrect installation.

We rotate the said tensioning rim 4 or composite hoop so that the centres of clamping lugs 41 coincide with the centre of the corresponding tensioner 6, 60. We move the rod 64, on which is the washer 64A, of the tensioner 6, 60 in the vertical position so that it passes through a narrowed opening 41 D and sits in groove opening 41 C of the tensioning rim in such way that between tensioning rim 4 and the rod head 64 is the washer 64A. We move the handles 62 of tensioners 6 towards the centre of the main shell of the drum 2 in the most closed position, and then we alternately screw the rods 64, until all the screws exert pressure on the tensioning rim 4 with the desired force, by which is tensioned also the membrane. The users of drums will by tapping the membrane 9 and on the basis of the tone generated by the device know when it is properly tensioned. By tightening the rods 64 with completely closed tensioners 6, 60 we tension the membrane 9 at the highest desired tone. By displacement of handle 62 of one or several tensioners 6, 60 against the extremely open position, the pin 67 slides along the toothed part 61 E of the base 6, 60 and the tension of the membrane is reduced. The combination of the pin 67 and a toothed part 61 E of the base, in the example shown, provides three positions of tensioner 6, 60, and thus three degrees of tension of the membrane 9. The number of positions of the tensioner in the preferred implementation is 2 or 3.

The procedure of the membrane replacement

When we want to replace the membrane 9, we place the drum 1 on an even surface so that the membrane 9, which we want to replace, is on the top. Then we unfasten all the tensioners 6, 60, which tension the membrane 9 so that we push the handles 62 outwards while we incline all the rods 64 approx. 90° to the outside. By this the composite or tensioning hoop 4 is released and can be taken off and the membrane 9 replaced.

Then we give the composite hoop back in its place, give all the rods 64 back in upright position in a corresponding groove openings 41 C of lugs 41 of the tensioning rim 4 and fasten or push all the handles 62 of tensioners 6, 60 into tensioned position.

With this the new membrane 9 is installed and also already tuned. Additional tuning is necessary only in the event that the new membrane 9 is not equal to the previous one. The described procedure allows very quick replacement of the membrane 9 namely in time of between 40 and 120 seconds.

The subject invention is described and illustrated by the specific implementation example, but which, in no case limits it. To skilled in the art it will be immediately clear that various modifications of individual details and/or elements of the described system for tensioning the membrane, its components, as well as the drum with a new system for tensioning the membrane are possible. All such modifications are in themselves obvious and comprised in the subject invention.

Claims

1. The system for tensioning the membrane of the drum, characterized in that it consists of:

the tensioning rim (4), which is flat, has an inner radius Rl , the outer radius R2 and on the outer circumference distributed a certain number N of equal clamping lugs (41) which extend radially from the outer circumference of the rim (4) to the radius R3, where each clamping lug (41) consists of two lateral, through radius mutually symmetric protrusions (41 A) through which the holes (4 IB) with diameter Dl are made in the axial direction, whose centres are located on the circumference of a circle with a radius of Rvl , wherein the holes (4 I B) are located at mutual axial distance XI , and the mutual angular distance al , and between the protrusions (41 A) are grooves (41 C) with the narrowed openings (4 ID), where the nearest holes (4 IB) of the two adjacent lugs (41) are located at a mutual angle distance βΐ and the sum of the angles al + βΐ = 360°/N;

a certain number N of membrane tensioners (6) for the tensioning of one membrane which consists of the base (61), the tensioning handle (62), two levers (63), pins (66, 67) with the appurtenant snap rings (66A, 67A), tensioning rod (64) with a washer (64A), and the pin (65), through which the hole with a thread (65B), in which the rod (64) fits, is made perpendicular to its longitudinal axis;

- the basic shell of the drum (2) with the holes (21) distributed around its outer circumference for mounting the membrane tensioners (6) and chamfered upper and lower edge (22);

- where the membrane tensioners (6) are fastened to the basic shell of the drum (2) by means of screw joints (80), and where the membrane (9) on the hoop-shaped frame is placed on the basic shell of the drum (2) and where the tensioning rim (4) is placed on the hoop-shaped frame so that the axis of each clamping lug (41) coincides with the vertical axis of the corresponding membrane tensioner (6).

2. The system for tensioning the membrane of the drum according to claim 1 , characterized in that it further comprises:

the resonance rim, which is composed of the equal or different segments of the resonance rim (3, 33), wherein the said segments of the resonance rim trace the arc with the angle δ, 62, and having the inside radius R4 and the external radius R5 and on the outer circumference distributed clamping lugs (31) extend radially from the outer circumference of the segment (3, 33) to the radius R6, where they are roundly terminated, where through said lugs (31) are in the axial direction made the holes (32) with diameter D2, the centres of which are located on the circumference with radius Rv2, where the angular distance between the centres of the holes (32) of the two mutually closest lugs (31) is a2, their mutual axial distance is X2, and where the angular distance between the centre of the hole (32) of any of the extreme lugs (31) and the centre of the hole (32) of its nearest lug (31) is β2; where:

the angle oc2 of the segment (3, 33) is equal to the angle al of the tensioning rim (4);

- the angle β2 of the segment (3, 33) is equal to the angle βΐ of the tensioning rim (4),

the radius Rv2 of the segment (3, 33) is equal to the radius Rvl of the tensioning rim (4);

axial distance X2 of the segment (3, 33) is equal to the axial distance XI of the tensioning rim (4);

- diameter D2 of the holes (32) of the segment (3, 33) is greater than the diameter Dl of the holes (4 IB) of the rim (4); and

- the inner radius R4 of the segment (3, 33) is smaller than the inner radius Rl of the tensioning rim (4);

where the segments of the resonance rim (3, 33) are clamped to the said tensioning rim (4) by means of screw joints (10A, 10B, IOC, 10D, 10E) so that all the holes (32) of the resonance segment (3) are placed coaxially above the positionally corresponding holes (4 IB) of the tensioning rim (4) and so that the segments are mutually laterally without contact, wherein the mutual distance between the upper surface of the tensioning rim (4) and the lower surface of the segments of the resonance rim (3, 33) is between 8 and 15 mm, preferably between 10 and 13 mm

3. The system for tensioning the membrane of the drum according to claim 1 , characterized in that it comprises:

the tensioning rim (4a), which is equal to the tensioning rim (4) described in claim 1 , only that it has in the middle between two adjacent clamping lugs (41) the hole (49) with chamfered edge; and

the supporting ring (3 A), which is made in one piece and is in the place (3B) interrupted, where it is at the place of interruption inserted the carrier plate (3C) for the pedal of the bass drum, where the carrier plate (3C) is attached to the supporting rim (3A) with two screws (50A) and to the tensioning rim (4) with the screw (50);

where the tensioning rim (4a) and the supporting rim (3 A) joined together by means of the screw joints (10A, 10B, IOC, 10D, 10E), as described in claim 2.

4. The membrane tensioner (6), as described in claim 1 , characterized in that the base (61 ) has an opening (61 A) with toothing (6 I E), where the toothing (6 I E) allows several positions of the membrane tensioner (6) and thus more tension levels of the membrane (9), which is most tensioned when the pin (67) is located in a position that is the farthest from the upper part (6 ID) of the opening (61 A), wherein the number of positions of the membrane tensioner (6) is 2 or 3.

5. The membrane tensioner (60), characterized in that it consists of the base (610) and double number of the elements (62, 63, 64, 64A, 65, 65A, 66, 66A, 67, 67A) contained in the membrane tensioner (6) as described in claim 1 , where the base (610) has a double toothing (610E, 61 OF), and in that, that with the tensioner (60) we independently tension both membranes (9) of the drum (1), wherein the said double-toothing (610E, 61 OF) allows more mutually independent tension levels of individual membrane (9).

6. The drum (1) with a system for membrane tensioning, characterized in that it comprises: the basic shell of the drum (2) having at the outer circumference distributed the holes (21) for mounting the membrane tensioners (6) and chamfered upper and lower edge (22);

two equal or different membranes (9) of the drum (1);

the number 2N of membrane tensioners (6) or the number N of membrane tensioners (60) attached around the circumference of the base shell (2) of the drum (1) in the corresponding holes by means of screw joints (80) ;

- two tensioning rims (4), according to description in claim 1.

7. The drum (1) with a system for membrane tensioning according to claim 6, characterized in that it further comprises:

two equal or different resonance rims consisting of equal or different segments of the resonance rims (3, 33) described in claim 2, wherein the segments of the resonance rims (3, 33) are attached on the tensioning ring (4) as described in claim 2; and/or

snares (7 A) which extend over the entire diameter of the membrane (9) and are at one side attached to the basic shell (2) of the drum (1), and on the other side are clamped by the tensioner (7B), where said snares (7A) are installed in contact with the lower membrane (9) and pass through the gap between the tensioning rim (4) and segments of the resonance rim (3, 33).

8. The drum (1) with a system for membrane tensioning, characterized in that it comprises:

- the basic shell of the drum (2) having at the outer circumference distributed the holes (21) for mounting the membrane tensioners (6) and chamfered upper and lower edge (22),

two equal or different membranes (9) of the drum (1 );

the tensioning rim (4 A) and the supporting rim (3 A), with the attached and inserted carrier plate (3C) for the pedal of bass drum, as described in claim 3, which are joined together by screw joints (l OA, 10B, IOC, 10D, 10E) as described in claim 2; the tensioning rim (4) as described in claim 1 and the carrying rim (30A), wherein the said retaining rim (30A) is equal to the supporting rim (3A), except that it is not interrupted and runs continuously around the entire circumference, which are joined together by means of the screw joints (10A, 10B, IOC, 10D, 10E), as described in claim 2.

9. Procedure for replacing the membrane (9) of the drum (1), characterized in that it comprises the following steps:

a) uncoupling of all the handles (62) of tensioners (6, 60) for specified

membrane (9);

b) tilting all the rods (64) of tensioners (6, 60) of specified membrane (9) by approximately 90° towards outside;

c) lifting the tensioning rim (4) or the composite hoop from the membrane (9); d) replacement of the membrane (9) with a new one, preferably equal

membrane (9);

e) reinstalling the tensioning rim (4) or the composite hoop on the membrane (9);

f) returning all the rods (64) of the tensioners (6, 60) of specified membrane (9) in vertical position so that the head of each rod (64) with a washer (64A) sits on the upper surface of the lugs (41) of the tensioning rim (4); and g) refastening all the handles (62) of tensioners (6, 60) of specified membrane (9), which were detached in the step a).

10. Procedure according to claim 9, characterized in that, that before step a)

comprises the step of uncoupling and removing the snares (7 A), and that after the step g) comprises the step of re-positioning and tensioning the snares (7 A).

1 1. The procedure according to claim 8 or claim 9, characterized in that, that after its completion it is not necessary to re-tune the membrane (9), and that the entire process takes from 40 to 120 seconds.