US3685389A

US3685389A - Drum

Info

Publication number: US3685389A
Application number: US65441A
Authority: US
Inventors: Franklin Theodore Bemben
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-20
Filing date: 1970-08-20
Publication date: 1972-08-22
Anticipated expiration: 1989-08-22

Abstract

An adjustable pitch musical drum is provided which includes a tubular cylindrical casing having its axis vertical, and a conventional drum head in tension over another end of the casing. A plurality of legs support the casing off the floor and a foot pedal is provided below the casing for adjusting the tension in the drum head. A tensioning mechanism connects the pedal to the drum head so that a relatively large movement of the pedal results in a small tensioning movement at the drum head to vary the frequency and hence the pitch of the note produced by the drum.

Description

United States Patent Bemben A3,685,389 1451 Aug. 2z, 1972 FOREIGN PATENTS 4OR APPLICATIONS [541 DRUM [72] Inventor: Fr Il. Tl om BembenMoom 1,095,169 12/1967 GreatBritain............L..4/4ll stone, Ontario, Canada Primary Examiner-Richard B. Wilkinson Assistant Examner-Lawrence R. Franklin [22] Filed:

Attorney-Rogers, Bereskin & Parr Aug. 20, 1970 [21] Appl. No.: 65,441 ABSTRACT An adjustable pitch musical drum is provided whichV includes a tubular cylindrical casing having its axis (gl. sullds/g vertical, and a conventional drum head in tension over another end of the casing A plurality of legs Support [58]. Field of Search..............84/41l, 411.1, 413, 419 the casing OH the floor and a foot pedal is provided nsion in the drum head. A tensioning mechanism connects the pedal to below the casing for adjusting the te [56] References Cited the drum head so that a relatively large movement of UNITED STATES PATENTS the pedal results in a small tensioning movement at the drum head to vary the frequency and hence the 2,259,268 10/194l ROblSQnm..........,........,84/4l9 pitch ofthe note produced by the drum. 2,261,119 11/1941 Ludwig et al................84/419 2,548,271 4/1951 Percy...........................84/411 2Clains, 4Drawing Figures PATENT'ED/uszz |912 3,685,389

snm 1 nr 2 FRANKLIN THEODORE BEMBEN PTENTDAuszz |912 SHEET 2 0F 2 FIG. 3

' INVENTOR. FRA-NKUN THEODORE BEMBEn DRUM This invention relates to a musical drum of a type which can be adjusted continuously to vary the frequency of vibration at the drum head to give a range of musical pitch. i

A drummer in a dance band, or in a group playing popular music, is often required to play a solo or to play a piece of music with a minimum of accompaniment. With the exception of the expensive and cumbersome timpani, drums are adjusted to a predetermined tension at the head or skin of the drum and the drum remains in this condition while it is being played. The frequency of vibration of the drum head is controlled by the fixed tension in the drum head. However, the drum can be made to make different sounds by hitting it with a variety of blows of different strength. Commonly this is said to change the pitch. For the purposes of the present description however, the word pitch is used to describe results obtained by varying the tension in the drum head rather than changes in the loudness of the note. For a given drum, although the loudness can be varied, the frequency of vibration (and hence the pitch) is fixed for a given head tension.

Commonly a drummer uses a number of different drums to obtain different effects and different notes. It is an object of the present invention to provide a variable pitch drum which a drummer can use to obtain new effects and which may be used in place of one of the drums presently used by a drummer.

Accordingly, in a particular preferred embodiment of the invention, an adjustable pitch drum is provided which includes a tubular cylindrical casing having its axis vertical, and a conventional drum head in tension over an upper end of the casing. A plurality of legs support the casing off the floor and a foot pedal is provided below the casing for adjusting the tension in the drum head. A vtensioning mechanism connects the pedal to the drum head so that a relatively large movement at the pedal results in a small tensioning movement at the drum head to vary the frequency and hence the pitch of the note produced by the drum.

The invention will be better understood with reference to the drawings, wherein:

FIG. 1 is a partially sectioned perspective view of a drum according to the invention;

FIG. 2 is a side sectional view on lines 2-2 of FIG. l;

FIG. 3 is a side sectional view on lines 3-3 of FIG. 1; and

FIG. 4 is a side sectional view on lines 4-4 of FIG. 1.

Reference is first made to FIG. l which shows a drum having a tubular cylindrical casing or shell 12 and a drum head 14. Three generally upright legs 16 support the casing 12 and a foot pedal assembly 18 is pivotally attached by screws 20 to a framework 22 which is in turn attached to the casing 12. Movement of the foot pedal assembly 18 results in moving a tensioning mechanism 24 having a relatively large mechanical advantage for tensioning the drum head 14. The mechanism 24 is arranged so that a relatively large movement of the foot pedal assembly 18 results in a small tensioning movement at the drum head with relatively small variations in the force required at the foot pedal assembly.

The casing 12 has a rounded upper side 26 for receiving the head 14 such that the head can be stretched radially over the rounded side 26 without damage to the head. Head 14 consists of a generally circular skin 28 attached at its periphery to a hoop 30 which is adapted to pass over the upper end of the casing 12. An annular rim 32 is pulled downwardly on the hoop 30 by eight axial bolts 34 to tension the skin 28. Each of the bolts 34 is threadably engaged in a cylindrical slider 35 which is free to slide axially in a housing 36 in response to movements of the pedal assembly 18. As the pedal assembly 18 is depressed, the sliders 35 and bolts 34 move downwardly and increase the tension in the skin 28 to increase the pitch of the note produced when the skin 28 is struck. Once the pedal assembly is released, the skin tension draws the mechanism 24 and pedal assembly 18 back to its original position corresponding to the lowest pitch in the drums musical range.

The legs 16 are adjustably mounted in leg supports 38 on the casing 12 for axial movement to adjust the height of the drum. Locking screws 40 are threadably engaged in respective leg supports 38 to lock the legs in place.

The framework 22 consists of a first member 42 which extends diametrically across the lower open end of the drum 10, and is attached to the casing l2 by integral upright portions 44 and fasteners 46 which pass through the upright portions 44 and through the casing l2. A second member 48 is welded to the member 42 and extends horizontally from the center of the first member 42 terminating in a further upright portion 50 which is attached by fasteners 52 to g e casing l2. A journal bearing 54 is attached to an upaer side of the first member 42 with the axis of the bearing coincident with the axis of the casing 12. The bearing slidably receives a lower push rod 56 which is part of the mechanism 24 and which has an enlarged lower end 58 for transmitting motion from the foot pedal assembly 18 to the tensioning mechanism 24.

The lower push rod 56 has an upper threaded portion 60 which projects through an opening in a lower pivot block 62. A pair of nuts 64 (one of which is shown) are threadably engaged on the upper portion 60, one above and one below the pivot block 62 to locate the pivot block on the lower push rod 56. A third nut 64 is also engaged on the portion 60 and serves as a stop for liniting downward movement of the push rod by engaging an upper surface of the journal bearing 54. Three lower moment arms 66 are mounted in the block 62 such that the arms are free to pivot and slide in the block 62. The arms 66 are spaced equally about block 62 and extend generally radially from the block 62 and are pivotally connected at their distal or outer ends by pins 68 to pivot support plates 7u. Each of the plates 70 is connected by bolts 72 which project through the casing 12 and are threadably engaged in a corresponding leg support 38. The arms 66 are connected to a respec one of three curved intermediate moment arms 74 .'xiiich extend downwardly and radially from a coupling plate 76. Each intermediate arm terminates at a forked end 78 which is pivotally attached by pins 80 to a corresponding arm 66 adjacent an outer end of the arm 66. Each of the moment arms 74 is shaped so that at its lower end, the fork 78 is substantially at right angles to the axis of an associated radial arm 66 and the upper end extends axially through the coupling plate 76. This threaded and has twognuts 80 (one'fofwhichfis shown) arranged one above and onebelow thef'plat'e 76^1tozat tach the arm to the plate. Y

. The plate 76 also has a central opening forr-ecieiving a threadedl upper push rod 82 which has two-nuts 83 (one of which is shown) engaged one above1and l'one below the plate 76 for locking the upper push rod 82-to the plate 76. Upper push rod 82 is threadablyengaged in an upper pivot block8 4 and threaded'intoth'e'block as will be explained; Eight equally spaced upper-moment arms 88 are mounted at their inner'ends `in=the block 84 such that the arms 88 are free tofpivot' in `'a vertical plane and to slide radially in block 84;:"I`he arms 88 extend radially from the block '841 a'nditheir respective outer ends engage in corresponding cylindrical sliders 35. Reference is next made to FIG. 2 which showsja moment arm 88 engaged in a cylindrical slider 35 which is free to move axially in the housingf36. The'arra'ngement shown in FIG. 2 is typical of all *eight of the couplings between each of the rods 88 and afcorresponding bolt 34. The rim 32 consists of a generally cylindrical portion 92 which is ilaredfoutwardlyatit's upper end 94 to extend above the skin 28; The upper end 94 is used for what is commonly called 'a rim shot. (This is when the drummer hits the skin 28``and upper portiong94 of rim 32 simultaneously to obtairia distinctive noise). A radially extending flange portion 96 extends outwardly from the low'er end of the portion 92 and has openings 98 for receiving eight bolts"34. The rim terminates in a lip which vextends downwardly from the outer edge of the portionff96to rigidify the rim 32. The underside of the radialportion 96 engages the hoop 30 of the head 14 so that the skin 28 is stretched when bolts 34 are tightened; lBolt34 is threadably engaged in the cylindrical slider 35 and the slider 35 is reciprocallyengaged in an upperopening 102 in the housing 36 and in a smaller clearance hole 104 at the bottom of the housing36; Bolts 106arelehgaged through a pivot plate 108-and projectlthro'u'gh the casing 12 to threadablyfengage in the housing36s'o that the bolts attach both the plate v108 andth'e housing 36 to the casing 12. f @i ai The upper radial arm 88 projects through an oversize opening 110 inthe` plate 108 and is prevented from moving inwardly through the opening 110 by av collar 112 attached to ,the armv 88. The outer end 114 ofithe arm .A88 is ofgreduced diameter and engages inl'a'contoured and slotted recess 116 which permits limited ana gular motion ofthe arm 88 `relative to the cylindrical' completing the .descriptionof the operation of the teni* Reference` is next made ,toFlG. 3 which shows'the 6,5.'

sioning mechanism 24 (FIG. 1 x

lowerpivotV block 62 and one of the lower moment arms 66 engaged .inone of three openings 118 `in they block 62. Each of theopenings is similar in shape to opening 116 (FIG. 2) to permit the arm 66 to move an- *glaily`-ina"vertical plane with respect to the pivot 'blocl62 and to'slide radially'as the block 62 moves axially'.` lTheirblock62' can be of any suitable metallic material or a rigid plastic. Also, if preferred a dense composition can be used, and this has the advantage thfatit tends'to damp undesirablevibrations in the' teh'sioning'mechanism 24.

""FIGi-4 illustrates the `upper pivot block 84 which has eightopnngs' 1 20 which are also similar in shape to "openings 1'16"(FIG. 2) in the slider 35. However, the rbl'tick84is'made of respective upper and lower halves 1241", 123 to facilitate assembly. The upper push rod 82 isthradablyengag'ed in the lower half 123 and locked in plticeby a nut 125. A bolt 86 extends through upper Thalffl21j'and ythreadably engages in lower half 123 to 'hld "the "halves `in engagement. Each opening 120 'receives a corresponding inner end 122 of an upper moment 88 to permit the end 122 to pivot in a verticalplaneaiid to move radially as the pivot block 84 moves axially. The inner end 122 is of reduced diameter t`linit lthesize of openings and hence to limit the size of the block 84. The block 84' is of similar material to the block 62 or any other suitable material e used.

, eturning now to FIG. 1, the pedal assembly 18 consflis'ts'of a bell-crank lever 124 having an inner end 126 'tV engage in a slot 128 in the enlarged lower end 58 of the..push rod 56. The bell-crank lever 124 is free to ftatej about a fitted bolt. 129 in a U-shaped bracket 4131.atvtachedby screws 20fto member 48, and has a hiny'ge130 attached to its outer end 132. The hinge 130 also attached to an upper end of a first member 134 adjustable link 136. A second member 138 is releasably connected by screws 140 to the first member 134:;and has a `plurality of holes 142 to permit the screws--ftolbe repositioned to adjust the length of the lin124136,.Av second hinge 144 is attached to the lower end ofthe second member 138 and to the upper end of an inclined foot plate 146. The foot plate 146 terminatesaat its" lower end in a pivotal connection to a base plate 148 which normally rests on the floor. l

'In operation, 4when a drummer places his foot on the inclined foot plate 146 with his heel on the base plate 148 hecanpivot the plate 146 about the baseplate 148 t0 rotate the-bellcrank lever 124 about the pivot bolt 129. This results in an upward force on the lower push rod'56to1slide'the rod 56 upwardly through vthe journal bearing A54.f\.l."his upward motion of the rod 56 andconsequentlybl''thepivot block 62 rotates the 4`vlower mo mentgarmslfabout pivot pins 68 in support plates 70. Because Ltheintermediate moment arm 74 is connected tot thellower moment arm 66 adjacent the pivot pins 68, thereis'aimechanical advantage created such that the upwar'drforcein', thelarms 74 is greater than the upward frceinthe push-'rod 56. i

fFrther mechanical advantage is obtained when the plate76 and pivot block 84 are moved upwardly by the force Linfth'elnioment arms 74. The pivot block transfers th:force' tother u'pper moment arms 88 which are pivoted adjace'nttheir outer ends in pivot plates 108to draw the cylindrical sliders 35 downwardly'. There is a relatively largefrnechanical advantage in the moment arms- 88 so that lthis combined with the mechanicaldvantage in the other parts of the mechanism 24 results in a very small downward movement of the rim 32 for a corresponding large movement of the inclined foot plate 146. Consequently the drummer is able to tension the skin 28 of the drum head 14 with relatively little effort.

One of the features of the adjustable drum is that the

moment arms

66, and 88 are inclined downwardly from the horizontal with the drum in the position shown in FIG. l by a predetermined angle such that when the foot plate is fully depressed, the

arms

66 and 88 are inclined upwardly from the horizontal by the same predetermined angle. This eliminates the need for expensive pivotal connections at the cylindrical slider 35, and pivot blocks 62 and 84 and gives a substantially constant mechanical advantage for all positions of the foot plate 146.

The pedal assembly 18 can be removed from the drum for transporting the drum by removing the screws 20. Also the legs 16 can be removed from supports 38 by first loosening screws 40 and sliding legs 16 out of the supports 38. The drum is then more suitable for carrying.

lf preferred, the lower push rod 56 can be made in two parts so that the part which projects downwardly beyond the frame 22 can be unscrewed from the rest of the rod 56 so that the drum will then fit into a conventional drum cover.

The lower end of the casing 12 as shown is uncovered. However, a wire mesh or other decorative cover can be placed over this end provided that it permits air displacement from within the drum to pass through it.

To assemble the drum, the legs 16 are locked in supports 38 to position the skin 28 at a desired height and the foot pedal assembly 18 is attached by inserting screws 20. lf necessary the inclination of the foot plate 146 can be changed by repositioning screws 140 in the adjustable link 136.

Once assembled, the drum is adjusted for use by tensioning the bolts 34 until the lowest required pitch is obtained. As the foot plate 146 is depressed, the drum will give a range of pitch beginning from the lowest and increasing in frequency to a maximum dictated by the tension in the skin 28. This permits a drummer to strike the skin 28 and by moving the foot plate 146 he can vary the pitch of the resulting note until the note dies out, By combining this effect with notes struck with the pedal in any one of a number of different positions it is possible to obtain affects which are pleasing to the ear and which can be used in combination with other musical instruments to provide novel musical effects.

What l claim as my invention is:

1. An adjustable musical drum comprising:

a. a cylindrical casing having a vertical longitudinal axis;

b. a drum head comprising: a circular skin and a hoop attached to the periphery of the skin and adapted to t relatively closely over the casing with the skin stretched over an upper end of the casing;

c. a rim adapted to engage the hoop for drawing the hoop over the casing to tension the skin on the said end of the casing;

d. adjustable means coupled to the casing and operable to draw the rim axially of the casing and towards the other end of the casing to apply a predetermined tension to the skin;

e. a tensioning mechanism operable to move the adjustable means axially thereby varying the tension in the skin between the predetermined tension and a higher tension;

f. a foot pedal assembly for coupling to the tensioning mechanism and to the mounting means for moving the tensioning mechanism to change the tension in the skin continuously between the said predetermined and higher tensions;

g. the adjustable means comprising: a plurality of the tensioning mechanism comprising:

i. a lower pivot block adapted to reciprocate along said axis in response to pedal assembly movements ii. an axial push rod reciprocally coupled to the casing and having an upper end attached to the lower pivot block and a lower end coupled to the foot pedal assembly for transmitting movement from the foot pedal assembly to the lower pivot block;

iii. a plurality of lower arms extending radially of the lower pivot block and pivotally connected at their respective outer ends to the casing;

iv. means connecting the inner ends of the lower arms to the lower pivot block so that the arms are free to rotate about their outer ends in response to axial movements of the lower pivot block; y

v. an upper pivot block adapted to reciprocate along said axis;

vi. a plurality of intermediate arms extending radially outwards and downwardly from the upper pivot block, each of the intermediate arms having an inner and connected to the upper pivot block and an outer end pivotally connected to a corresponding lower arm intermediate the ends of the lower arm so that movement of the lower pivot block in one axial direction is transmitted by the lower and intermediate arms to the upper pivot block to move the upper pivot block in the same direction;

vii. a plurality of upper arms extending radially from the upper pivot block and having outer ends projecting through the casing;

viii. fulcrum means coupling the upper arms to the casing adjacent outer ends of the upper arms for pivotal movement of the upper arms such that a relative large movement of the inner ends of the upper arms results in a relatively small movement of the outer ends; and

ix. means coupling respective inner and outer ends of the upper arms to the upper pivot block and to the sliders whereby axial reciprocal movement of the upper pivot block in response to intermediate the ends of the bell-crank lever; a footplate pivotally connected to the outer end of the bellcrank lever so that pressure in the foot-plate results in angular movement of the bell-crank lever; and means coupling the lower end of the push rod to the bell crank lever for transmitting upward movement of the inner end of the bell-crank lever to the push rod.

Claims

1. An adjustable musical drum comprising: a. a cylindrical casing having a vertical longitudinal axis; b. a drum head comprising: a circular skin and a hoop attached to the periphery of the skin and adapted to fit relatively closely over the casing with the skin stretched over an upper end of the casing; c. a rim adapted to engage the hoop for drawing the hoop over the casing to tension the skin on the said end of the casing; d. adjustable means coupled to the casing and operable to draw the rim axially of the casing and towards the other end of the casing to apply a predetermined tension to the skin; e. a tensioning mechanism operable to move the adjustable means axially thereby varying the tension in the skin between the predetermined tension and a higher tension; f. a foot pedal assembly for coupling to the tensioning mechanism and to the mounting means for moving the tensioning mechanism to change the tension in the skin continuously between the said predetermined and higher tensions; g. the adjustable means comprising: a plurality of axial bolts each of which has a head end engaged against the rim and a threaded end; and a plurality of sliders coupled to the casing for reciprocal axial movement, each slider having an axially extending opening for threadably receiving a corresponding threaded end of a bolt, the sliders being coupled to the tensioning mechanism so that the bolts can be tightened to draw the rim towards the sliders to apply the predetermined tension to the skin; and h. the tensioning mechanism comprising: i. a lower pivot block adapted to reciprocate along said axis in response to pedal assembly movements ii. an axial push rod reciprocally coupled to the casing and having an upper end attached to the lower pivot block and a lower end coupled to the foot pedal assembly for transmitting movement from the foot pedal assembly to the lower pivot block; iii. a plurality of lower arms extending radially of the lower pivot block and pivotally connected at their respective outer ends to the casing; iv. means connecting the inner ends of the lower arms to the lower pivot block so that the arms are free to rotate about their outer ends in response to axial movements of the lower pivot block; v. an upper pivot block adapted to reciprocate along said axis; vi. a plurality of intermediate arms extending radially outwards and downwardly from the upper pivot block, each of the intermediate arms having an inner and connected to the upper pivot block and an outer end pivotally connected to a corresponding lower arm intermediate the ends of the lower arm so that movement of the lower pivot block in one axial direction is transmitted by the lower and intermediate arms to the upper pivot block to move the upper pivot block in the same direction; vii. a plurality of upper arms extending radially from the upper pivot block and having outer ends projeCting through the casing; viii. fulcrum means coupling the upper arms to the casing adjacent outer ends of the upper arms for pivotal movement of the upper arms such that a relative large movement of the inner ends of the upper arms results in a relatively small movement of the outer ends; and ix. means coupling respective inner and outer ends of the upper arms to the upper pivot block and to the sliders whereby axial reciprocal movement of the upper pivot block in response to movement at the foot pedal assembly pivots the upper arms in the fulcrum means resulting in axial movement of the sliders in the opposite direction to the direction in which the upper and lower pivot blocks move.

2. An adjustable musical drum as claimed in claim 1 in which the foot pedal assembly comprises: a bell crank lever having an inner end and an outer end the bell-crank lever being pivotally attached to the casing intermediate the ends of the bell-crank lever; a foot-plate pivotally connected to the outer end of the bell-crank lever so that pressure in the foot-plate results in angular movement of the bell-crank lever; and means coupling the lower end of the push rod to the bell crank lever for transmitting upward movement of the inner end of the bell-crank lever to the push rod.