Abstract:
The invention relates to the modularity of a reversible symmetrical single-pillar vertical support assembly (the Tower) which is the major structural component for a drum beating pedal apparatus (drum pedal). Said drum pedal can also be used to beat, without limitation, other musical instruments and musical accessories. Upon this Tower can be constructed various single-beater, multiple-beater and remote drum pedals and drum beating mechanisms according to the operator&#39;s requirements. This modular single-Tower drum pedal system also comprises several ancillary inventions which also can be applied in concert with or independently of the said Modular Single-Tower Drum Pedal System. These ancillary inventions relate specifically to drum pedal elements that directly affect and control the adjustability of footboard length; chain and/or strap length; single and multiple drum beaters in all axial positions including side-to-side, up-and-down, and fore-and-aft directions; beater stroke arc length and beater velocity; independent multiple beater adjustability; reduced friction spring-rocker floating-bearing support assembly; adjustability of the eccentricity of the cam hub; and a hexagon-shape drum beater shaft for secure 3-way position of drum beater head.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to musical drums and the beating of musical drums the operator using a mechanical apparatus. The invention relates specifically to the design and construction of single-beater and multiple-beater drum pedals and more specifically to a single-pillar vertical support assembly (called the Tower or the single-Tower) and the attachable mechanisms and accessories that comprise the named Modular Single Tower Drum Pedal System. 
       BACKGROUND OF THE INVENTION 
       [0002]    The function of a mechanical drum beating pedal apparatus is to effect the beating of a drum or other musical instruments or musical accessories by impelling the drum beater or beaters of the apparatus with the operator&#39;s foot or feet or other convenient or appropriate conveyance. A conventional drum pedal is normally comprised of a vertical support structure attached to a base structure; said base structure is attached to a musical drum instrument. Said vertical support structure normally carries a primary horizontal driveshaft carried by one or two bearings which are normally attached to said vertical support structure, which is in turn attached to a foot pedal, the heel of which is pivotally attached to the base structure and the front of the pedal is articulately attached to the driveshaft so that the horizontal driveshaft is rotated when the pedal is depressed by the operator&#39;s foot. A spring balanced return mechanism repositions the horizontal driveshaft when foot pressure is released by the operator, returning the rotated driveshaft to its original position. The drum beater is attached to said horizontal driveshaft so that, as the horizontal driveshaft is rotated by the depressed pedal, it strikes the head of the drum, and as the operator&#39;s foot pressure is released, the beater returns to its original position. The vertical support structure of a conventional drum pedal is normally comprised of two vertical support pillars, which are moulded or otherwise attached to the base structure of said pedal, but sometimes the drum pedal is comprised of one vertical pillar moulded or attached to the said base structure. Usually, neither the conventional two-pillar vertical support structure nor the conventional single-pillar support structure can be converted into a multiple-beater drum pedal apparatus without the addition of costly parts that require additional design, tooling and special manufacture. The conventional two-pillar vertical support pedal structure, in order to be converted to accept a second beater for a conventional two-beater pedal, requires the costly addition of a third support pillar so that two separated drive shafts can be operated independently. Also, this third support pillar must be designed so that it can accommodate secondary foot pedal activation from either the right or the left, depending on the requirements of the operator which would include the requirement for the operator to drive the pedal secondary pedal with the left foot if the primary pedal is played with the right foot and conversely, the requirement to drive the secondary pedal with the right foot if the primary pedal is operated by the left foot. Single vertical pillar pedals normally support and carry the horizontal driveshaft with one bearing only, creating undue stress on said bearing. The field is devoid of vertical single-pillar single-beater drum beating pedal mechanisms that easily convert to double-beater pedals. The normal incidence of single vertical tower bass pedals is found used as part of a double beater apparatus and is normally used as the secondary drive pedal with no beater capability attached. 
         [0003]    The primary purpose of this invention, named the Modular Single-Tower Drum Pedal System, is to provide a modular solution to creating a multiplicity of pedal beater configuration choices with the fewest numbers of relatively costly cast or machined parts. It is the modularity of the single-Tower design, which has a symmetrical shape to work either from the left or the right side of the pedal base structure, and that it is attachable and detachable on either the right side or the left side or both sides of the base structure, that is the essence of this invention. Also, two single-Tower pillars, sharing a single bearing support arm, can be mounted together on one pedal platform plate to create either a double-beater pedal or a reinforced double-Tower single-beater pedal with the addition of the requisite longer single driveshaft supported by bearings at either end of said longer driveshaft. The single-beater drum pedal can be modified easily to act as the drive for a double beater pedal for either the left foot or the right foot simply by choosing whether the single-Tower support structure is attached to the left side or the right side of the base structure. The single-Tower attaches and detaches easily to and from the base structure with ordinary bolt and nut fasteners that are simple and obvious for the operator to change with a normal wrench or other basic tool of appropriate design. Furthermore, the single-Tower combined with the Bearing Support arm securely support the horizontal driveshaft with two bearings supporting said driveshaft toward the ends of the said driveshaft. Said bearings are captured within the assembly of the single-Tower support structure as a consequence of the assembly of the tower and bearing support arm. The key elements are a Tower, which mated to a Bearing Support create the single-Tower. Two Towers can be mated to a single Bearing Support to create the double beater pedal, where two beaters are supported on a pedal base structure. Key to the success of the design is the ability to mate the Bearing Support Arm to one Tower to create the single beater pedal and to mate the single Bearing Support Arm to two Towers to create the double beater pedal. Furthermore, this invention, the Single-Tower Modular Drum Pedal System, is complemented by several new and unique designs and inventions for beater holder and adjustment, drive mechanism adjustment, spring functionality and foot pedal adjustment. 
       DESCRIPTION OF PRIOR ART 
       [0004]    Three examples of conventional drum pedals are shown in Fig. AA, Fig. BB and Fig. CC. 
         [0005]    Fig AA shows a conventional twin pillar drum pedal assembly. Fig. BB shows a conventional double pillar double beater pedal and Fig. (CC) shows a conventional single pillar drum pedal used as a secondary pedal to drive the secondary beater of a conventional double pillar double beater pedal. 
         [0006]    Fig. AA illustrates the conventional two-pillar single beater drum pedal which usually includes a base structure  91  with two vertical pillars  92  attached to and extending vertically from a top surface of the base structure  91  and a horizontal driveshaft  93  is connected between the two vertical pillars  92  and generally supported by bearings at each end of said driveshaft  93  and generally at the top end each vertical pillars  92 . The drum beater  94  is securely connected to the driveshaft  93 . One end of a foot pedal  95  is pivotally connected to the base structure  91 . An articulated driving assembly  931  using chainlink or strap connects between the beater  94  and the other end of the foot pedal  95 . To activate the beater  94  the operator depresses the foot pedal  95  which results in rotating the driveshaft  93  which in turn drives the beater head of beater  94  to strike the head of the drum. The drum is connected to the base structure  91  by means of a clamped attachment  98 . The drumhead (membrane of drum) is aligned perpendicularly from the base structure  91  of the pedal. A spring-actuated returning device  96  is connected to one of the two vertical pillars  92  and includes an extension spring  97  which has one end connected to the a boss in the vertical pillars  92  and the other end of the spring  97  is connected with the spring return mechanism  99  which is attached to the driveshaft  93  so that the driveshaft  93  is rotated back to its initial position when the user releases pressure to the foot pedal  95 . 
         [0007]    Fig. BB is based on the pedal in Fig. AA. This double beater pedal shows a pedal  95 P is part of the primary pedal and positioned to be operated by the right foot and pedal  95 S is part of the secondary pedal and is positioned to be operated by the left foot. The pedal  95 S when depressed activates the drive mechanism  931 S rotating shaft  93 S which is directly connected to driveshaft  93 L by direct connection  932 . A return spring assembly  96 L is directly connected and returns the beater  94 L to the original position when foot pressure is relieved on pedal  95 S. Drum beater assemblies  94 L and  94  R, Left and Right operate independently. Pedal  95 S activates beater  94 L and pedal  95 P activates beater  94 R. In order to facilitate this independent rotation of the two beaters these beaters need to rotate on separate driveshaft which in turn need to be supported independently. In order to do this a third vertical pillar  923  is attached to pillar  922 R. Should the operator choose to place the secondary pedal on the left in order to operate the primary pedal with the right foot and the secondary pillar with the right foot, then a different costly change needs to be made to create the  923  to be attached to  921 R Also, there is a weakness in the top of  923  where the separate drive shafts  93 R and  931 R meet inside  923 . 
         [0008]    Fig. CC shows essentially the same pedal features and functions as BB but the secondary pedal has a driveshaft  93 SS supported by only one pillar  92 S and one bearing  92 B. Lack of support at both ends of the driveshaft  93 SS offers no resistance to the twisting torque created by the playing of the mechanism. This single pillar design cannot be used to drive a double beater pedal as a secondary pedal played by the right foot. A different and costly single pillar attached to the left side of the base would be required. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention relates to a drum pedal assembly which includes a horizontal base structure upon which at least one vertical pillar (the Tower) extends and a support has a connection section which is connected to a connection section extending laterally from at least the one vertical pillar to create a single-pillar support assembly (the single-Tower). A drive transmission unit has a horizontal driveshaft which is rotatably connected between at least the assembly of one vertical pillar and the support (the single-Tower assembly), and a pedal which is pivotally connected to rotate the driveshaft. A beater assembly is connected to the driveshaft and driven by the transmission unit. The vertical symmetrical Tower can be connected to either side of the base structure to meet the requirements of different operators and users. A drum beater adjusting unit, a pedal adjusting unit and a spring adjusting unit can be cooperated with the beater assembly to provide more adjustment functions. 
         [0010]    The primary object of the present invention is to provide a drum pedal assembly that includes an adjustable single vertical tower attached to the base so that different users can use the beater assembly with more convenience and can easily configure the apparatus to be used in a variety of conventional and non-conventional single-beater and multiple-beater applications. 
         [0011]    Another object of the present invention involves enhanced adjustability so as to provide a drum pedal assembly wherein the angle between the pedal and the base, the length of the base, the position of the beater along the driveshaft, the striking area of the beater on the drum head, the relative positions of double beaters on one drum head, the distance between the beater and the drum and the speed that the beater returns to its initial position can be all be adjusted. 
         [0012]    The present invention will become more obvious from the following descriptions when taken in connection with the accompanying drawings which show, for purposes of illustration only, some of the preferred embodiments in accordance with the present inventions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Fig. AA shows a conventional single beater drum pedal with double pillars; 
           [0014]    Fig. BB shows a conventional double beater drum pedal with double pillar secondary pedal and double pillar primary pedal; 
           [0015]    Fig. CC shows a conventional and common double beater pedal with single pillar secondary drive pedal and double pillar primary pedal; 
           [0016]      FIG. 1  is a perspective view of the drum pedal with single-Tower single-beater assembly of the present invention. The single-Tower is attached to the right side of the base structure. This perspective is viewed from the operator&#39;s right side; 
           [0017]      FIG. 2  is a perspective view of the drum pedal, as shown in  FIG. 1.0 , viewed from the operator&#39;s left side; 
           [0018]      FIG. 2A  is a perspective view of the drum pedal with the single-Tower single-beater assembly attached to the left side of the base structure, viewed from the operator&#39;s right; 
           [0019]      FIG. 2B  is a perspective view of the drum pedal with two one single-Tower assemblies mounted on the right side and a second Tower mounted on the left side. This shows a double-Tower pedal with one beater. It is viewed from operator&#39;s right; 
           [0020]      FIG. 3  is an exploded perspective view of the single-tower single beater assembly, viewed from the operator&#39;s right side. This illustration serves to separate the various drum pedal elements including base assembly  10 , single-Tower assembly  20 , foot pedal assembly  30 , drum beater assembly  40 , drive transmission assembly  50 , drum clamp assembly  60 , and spring return assembly  70 ; 
           [0021]      FIG. 4  is an exploded perspective view of the pedal base plate assembly showing front and read base plates and the base plate assembly unit; 
           [0022]      FIG. 5  shows two side elevation views,  FIGS. 5A and 5B , showing two adjustments of the pedal base plate,  FIG. 5A  in the shortened position and  FIG. 5B  in the lengthened position; 
           [0023]      FIG. 6  is a perspective exploded view showing the single-Tower assembly including the Tower and Bearing Support Arm and the driveshaft assembly; 
           [0024]      FIG. 7  is a perspective exploded view showing two Towers, one Bearing Support Arm, two driveshaft assemblies and the stabilizing rod assembly; 
           [0025]      FIG. 7A  is a perspective exploded view showing two Towers and one Bearing Support Arm, viewed from left-also shows stabilizing rod and assembly mating areas; 
           [0026]      FIG. 8  is a perspective exploded view showing the foot pedal assembly including the heel plate and the Chain-Slider assembly; 
           [0027]      FIG. 9  shows two perspective section views,  FIGS. 9A and 9B , of foot pedal Chain-Slider and Chain-Anchors showing shortened chain position and lengthened chain positions; 
           [0028]      FIG. 10  shows two partial perspective views,  FIGS. 10A and 10B , showing the Chain-Slider without chain attached to illustrate shortened and lengthened pedal foot board positions; 
           [0029]      FIG. 11  shows two partial perspective views of the reversible toe stop,  FIGS. 11A and 11B , attached in two possible positions forward and reverse; 
           [0030]      FIG. 12  shows an exploded perspective view of the beater assembly; 
           [0031]      FIG. 13  shows two beater assembly side views,  FIGS. 13A and 13B  of beater adjustability fore and aft positions and beater height adjustment capability; 
           [0032]      FIG. 14  shows 3 front elevation views of beater assembly showing rotatable and extendible adjustability side to side and up and down variable beater length and beater position; 
           [0033]      FIG. 15  shows 5 illustrations,  FIGS. 15A ,  15 B,  15 C,  15 D,  15 E, all front elevations detailing views of the full double pedal assembly including  FIG. 15A  showing the one double-Tower primary pedal and one single-Tower drive pedal which comprise a double beater pedal with secondary pedal driven by operator&#39;s left foot, plus 4 views of various double beater relative position placements on primary two-Tower pedal; 
           [0034]      FIG. 16  shows single-Tower pedal with the triple-head beater mounted on hex shaft with 3 choices of playing positions; 
           [0035]      FIG. 17  shows an exploded perspective view of the eccentric cam drive transmission assembly with drive chain; 
           [0036]      FIG. 18  shows several views,  FIGS. 18A ,  18 B,  18 C and  18 D, of the eccentric cam adjust lever in various positions; 
           [0037]      FIG. 19  shows two side elevation views of the eccentric adjust cam assembly in two positions viewed from the opposite side of cam adjust lever,  FIGS. 19A and 19B ; 
           [0038]      FIG. 20  shows an exploded perspective view of the drum clamping assembly; 
           [0039]      FIG. 21  shows 6 illustrations,  FIGS. 21A ,  21 B,  21 C,  21 D,  21 E and  21 F, various views drum clamping assembly functionality; 
           [0040]      FIG. 22  shows exploded perspective view of the spring return rocker assembly; 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0041]    Referring to the drawings, wherein like features are denoted by corresponding reference numbers, the preferred embodiments of the inventions are thereby illustrated and described. 
         [0042]    Referring to  FIG. 3  the exploded perspective shows a drum pedal assembly illustrating the major components of the present invention which comprises a base-structure assembly  10 ; a single-Tower assembly  20  including drive-shaft, Bearing Support Arm and bearings, which attach to the base-structure assembly  10  in the right side position; an adjustable pedal board unit  30  including footboard, heel plate and toe-stop, an adjustable drum beater assembly  40 ; an adjustable drive transmission assembly  50  including cam and chain or strap; a drum clamping assembly  60 ; and a spring-actuated returning assembly  70 . 
         [0043]    Referring to  FIG. 4  the base structure assembly  10  is composed of a front plate  11  and a rear plate  12  wherein the front plate  11  and the rear plate  12  have an overlapping section. A guide slot  14  is defined in one end of the rear plate  12  and a positioning bolt  144  extends through the front plate  11  and is movably engaged with the guide slot  14 . A positioning pressure plate  143  is connected to the positioning bolt  144  so as to press the overlap portion of the front and rear plates  11  and  12  to position the front and rear plates  11  and  12 . A handle nut  141  is connected to the screw section at the top of positioning bolt  144  and on top of the positioning pressure plate  143 . The extended lip shape of positioning pressure plate  143  allows base rear plate  12  to be guide under pressure plate  143  for ease of engagement. Two parallel grooves  121  embossed in rear plate  12  and matching two parallel grooves  111  embossed in front plate  11  serve to guide rear plate  12  over front plate  11  so that alignment is ensured. 
         [0044]    The overall length of the pedal base-structure assembly  10  can thereby be adjusted and plate base-structure assembly  10  can be disassembled for pedal folding if so needed. 
         [0045]    Normally a pressure plate  143  is not seen to be used in similar applications in other pedals and only flat washer  142  is used. In that case a spring is necessary to separate washer  142  from plate parallel grooves  111 . Separation of the washer  142  is necessary to allow rear plate  12  to slide over front plate  11  guided by bolt  144  and slot  14 . Without a spring or plate  143  the operator would be required to lift the washer  142  by other means thereby making assembly and disassembly awkward. In this case, plate  143  automatically lifts washer  142  as rear plate  12  is guided past bolt  144  through slot  14 . 
         [0046]    Also shown in  FIG. 4  in rear plate  12  there are the 2 sets of 4-hole groupings  11 - 4 R and  11 - 4 L which serve to accept the 4 bolts for the single-Tower to attach to the front plate  11 . A single-Tower mounted on the right side of the front plate  11  would use the 4-hole grouping  11 - 4 R on the Right side of the front plate  11  and a single-Tower mounted on the left side of front plate  11  would use 4-hole grouping  11 - 4 L on the Left side of front plate  11 . Mounting 2 Towers upon one front plate  11  would require using both 4-hole groupings  11 - 4 R and  11 - 4 L. There are 6 holes in front plate  11  all numbered  112 . They serve to attach individually or severally accessory connector plates not shown, which, for one example would allow the connecting together of two or more base plate structures or ancillary base plates. The overall length of base-structure assembly  10  can be lengthened or shortened by loosening nut  141 , pulling apart or pushing together plates  11  and  12 , which would slide upon the embossed grooves  121  on rear plate  12  and embossed grooves  111  on front plate  11 . Once the desired length is achieved the position is secured by tightening nut  141 . Additionally, rear plate  12  can be disengaged completely from front plate  11  in order to facilitate the folding and compacting of the pedal assembly for travel and or storage. Reassembly is simplified in guiding rear plate  12  using slot  14  to engage and mate with bolt  144  slipping the front end of rear plate  12  between pressure plate  143  and front plate  11 , thereby lifting the loosened pressure plate  143 . This way the adjustment of length of base-structure assembly  10  is facilitated. 
         [0047]      FIG. 5  shows two side-elevation views of the complete single-Beater single-Tower pedal. The top figure shows  FIG. 5A  shows the base-structure assembly  10  in the shortened position and the resulting footboard unit  30  is positioned forward. The lower  FIG. 5B  shows the base-structure  10  in its lengthened position showing the resulting footboard unit  30  is positioned rearward, and the drive chain  33  as a result has moved from a perpendicular resting position to an angular resting position. Adjusting the length of the footplate adjusts the position of the pedal footboard and results in adjusting the angle of the drive chain  33 . Also seen clearly in  FIG. 5  is a side view of the drum clamping assembly  60 . Also shown in the side elevations are nut  141  and pressure plate  143 . Rear plate  12  is pressed between pressure plate  143  and front plate  11  by engaging and turning nut  141 . 
         [0048]    The Tower  20 , see  FIG. 6  connects to the top of the base-structure assembly  10  at one set of the positioning holes, see  FIG. 4 , either the set of 4 holes  11 - 4 L for Left mount or the set of 4 holes  11 - 4 R for Right mount defined through the front plate  11  located on either the right or the left side of front plate  11  using, see  FIG. 6 , the set of 4 bolts  22 - 4  and the set of 4 nuts  22 HN- 4 . The single-Tower assembly  20  is also shown in  FIG. 3  attaching to base-structure assembly  10  on the right side of front plate  11 . The tower  21  is attached to bearing support  22  using stabilizer rod  24  screwed into nut  24 N which is set into hex hole  24 NH which is cast into the upper side of tower  21 . Tower  21  has an assembly section  211  which consists of a vertical laterally protruding ridge  211 A and a horizontal vertically protruding ridge  211 B. Bearing support  22  has a mounting section  222  with a vertical inset groove  222 A and horizontal inset groove on the underside  222 B. The attaching of Tower  21  to support  22  involves mating ridge  211 A with groove  222 A and ridge  211 B with groove  222 B. This mating of ridges and grooves assures a solid connection that will ensure the resisting of twisting and turning of tower  21  and support  22 . The tower has a round flat bottom cavity that accepts bearing  231  and likewise support  22  has a matching cavity to accept a matching bearing  231 . These two bearings support drive shaft  23 L which is captured between Tower  21  and bearing support  22 . This is a unique design solution to installing a drive shaft and bearings. Normally bearings need to be secured by press fitting or secondary screw pressure, adding costs and also adding to the possibility of compromised performance of the bearings. This method of bearing and driveshaft assembly is a direct result and is intended as one of the preferred embodiments of the System. It is noted that the symmetrical Tower  20  can be connected to right side or left side of the front plate  11 . 
         [0049]    The driveshaft transmission assembly  23  has a drive shaft  23 L if long and  23 S (shown in  FIG. 7 ) if short which may have a hexagonal or circular or partly circular and partly flat cross section, and is attached to a foot pedal plate  31  (shown in  FIG. 8 ) The driveshaft transmission assembly  23  is rotatably connected between the Tower  21  and the support  22  with two bearings  231  mounted on two ends of the driveshaft  23 . The two bearings  231  are respectively connected to the at least one Tower  20  and the support  22 . 
         [0050]    The pedal board unit  30  in  FIG. 8 to 11  shows pedal board unit  30  including foot pedal plate  31 , heel plate  32 , drive chain  33 , toe stop  35 , chain set  36  and chain cap  37 , the foot pedal plate  31  is pivotally connected to the base structure assembly  10  at heel plate  32  and is able to drive the foot pedal plate  31  to rotate. toe stop  35  screw on the front of foot pedal plate by two screws  351 , to prove the toe can&#39;t over the foot pedal plate  31 . chain set had fit in the front under of foot pedal plate  31  by bolts  361 , 362  and nut  363 , to connected the chain  55  by chain cap  37  by blot  371  and nut  372 , the chain set  36  can adjusting the position of chain  55 . 
         [0051]    The beater assembly  40  in  FIG. 12  is driven by the drive transmission assembly  50  and is co-rotated with the pedal board unit  30 . The beater assembly  40  shows in  FIG. 12  has a beater holder  41  which is connected to a clamp member  45  and movably connected to the driveshaft  23 L or  23 S. The clamp member (beater clamp)  45  has a passage  441  through which the driveshaft  23 L or  23 S securely extends so that the clamp member  45  is co-rotated with the driveshaft  23 L or  23 S. The clamp member  45  further has a clamp portion  451  which includes a slot  452  (the slot  452  is the open end or the clamping device) so as to define two parts, and the beater holder  41  is located in the clamp portion  451 , a bolt  46  extends through the clamp portion  451  to squeeze the two ides of slot  452  to clamp the beater holder  41  in the clamp portion  451 . Two urging crews  442  are threadedly connected to the clamp member  45  and contact against the driveshaft  23 L or  23 S so that the clamp member  45  is securely connected to the driveshaft  23 L or  23 S. A polygonal engaging hole  411  is defined through the beater holder  41  and a beater  42  has a beater shaft rod  43  which is engaged with the polygonal engaging hole  411 . The beater shaft rod  43  has a hexagonal cross section and the polygonal engaging hole  411  is a polygonal six-sided hole. A positioning bolt  412  extends from an underside of the beater clamp  45  to contact against and position the connection rod  41 . The beater  42  has a plurality of beat faces  421  which are located on an outer periphery of the beater  42 . The number of the beat faces can be one or two or three or any number and the cross section of the beater shaft rod  43  and the shape of the engaging hole  411  can also be rectangular or round or oval. The beater  42  shown in cooperation with the hexagonally shaped beater shaft rod  43  and 6-sided hole  411  conspire to provide 3 secure beater beating positions. The beater faces  421 ,  422  and  423  can be made of different materials such as wood, plastic, metal, felt or cork. These different materials provide a different sound when the beater strikes the drum. Beater faces shown,  421  and  422  are attached to beater  42 . Beater face  423  is moulded as part of beater  42 . The hexagon shape beater shaft rod  43  is aligned with three beater faces  421 ,  422 , and  423  on beater  42  provide three beater face choices for the operator. 
         [0052]    Additionally, the hexagon shape of the beater shaft rod  43  engaged in the six-sided polygonal shaped hole  411  in beater holder  41  assists in preventing twisting of beater face during operation. The twisting of the beater face during operation is a problem encountered by multifaceted drum beaters with round shaped shafts. Ineffective locking devices have been tried but are not secure enough. The hexagonally shaped beater shaft rod  43  fitting into six side hole  411  is another preferred embodiment of this invention. Another function of the beater clamp  45  is to allow rotational adjustment for beater  42  and fore and aft adjustment for beater  42  because beater holder  41  is positionable lengthwise in the clamping portion  451 . These features, both the rotational and fore-and-aft adjustability of the beater  42  are provided by the invention and design of beater clamp  45  are preferred embodiments of the invention. Lateral adjustment of the beater clamp  45  on driveshaft  23 L or  23 S is also a feature of the design.  FIG. 13  shows two drawings  FIGS. 13A and 13B , which serve to further illustrate the fore and aft adjustability of beater holder  41  in beater clamp  45 .  FIG. 13A  shows beater is positioned “aft” in clamp  45  and  FIG. 13B  shows beater is positioned “fore” in beater clamp  45 . The “fore” and “aft” positions dramatically change the feel of the pedal because the leverage of the beater relative to the rotating centre of the drive shaft is changed. The operator if offered an easy way to adjust this aspect of the pedal feel.  FIG. 14  shows three examples of beater  42  positions provided by the clamp  45  adjustability. The view of elevation in  FIG. 14  is on the same plane as the drum head membrane. This means the operator can choose with precision the area of the drum head being struck by the beater  42 . This is another important embodiment of the invention which is not found in existing prior art. More possibilities adjusting double beaters are shown in  FIG. 15 . There are five drawings in  FIG. 15 . These drawings show the advantage of independently adjustable beaters whereby the beater head can be adjusted individually to that the beaters can be set to strike the drum head equidistantly by the double beaters. Also, the beaters can be set to strike differing lengths of distance from the centre of the drum. This is a choice of adjustment that is not found in other pedal systems and is one of the preferred embodiments of this pedal system.  FIG. 15A  shows a double pedal, in front elevation view, with two beaters set to strike the drum head equidistantly from the centre of the drum head. In this case the beaters could be set to strike any areas of choice.  FIGS. 15B ,  15 C,  15 D and  15 E show beater striking patterns that suggest only a few of the possible choices offered the operator. For example, the operator may choose to have the one beater head strike very close to the centre of the head and the second beater to strike further away, creating two entirely different sounds. As well, two beaters striking equidistantly should create very similar sounding beats. 
         [0053]    The drive transmission assembly  50  is connected between the driveshaft  23 L or  23 S and a chain  55  which is moved by the drive transmission assembly  50  so as to affect the height of the foot pedal plate  31 , and the position the beater assembly  40 .  FIG. 17  shows the drive transmission assembly  50 , which includes an eccentric cam hub  51  which is connected to the drive shaft  23 L or  23 S. two elongate holes, slots  513  and  514  are defined through the front face of the cam hub  51 . The back of the cam has one longer elongate slotted hole  512 . The eccentric cam  53  serves to support and attach either a chain  55  or a drive strap. The cam  53  is movably connected to the one of the elongate holes  512  of the cam hub  51  and the chain  55  has one end fixed to the cam  53  fixed by chain cap  37  and the other end of the chain  55  is connected to the foot pedal plate  31 . An adjusting teardrop shaped knob (cam lever)  54  with a protruding stud  541  with an eccentrically placed off-centre hole  542  (show in  FIG. 18 ) is connected through the cam lever hole  539  fashioned in cam  53 , A bolt  543  extends through the cam lever hole  539  and another elongate hole  512  in the cam hub  51 , and the cam lever  54  has an outer periphery on stud  541  which is rotated eccentrically as a result of the hole  512  being placed off centre. See  FIG. 17 . Bolt  543  passes through washer  532  and cam lever  54  through hole  542  and is fixed at the screw end with nut  544  which fits into one end of hole  512  fixed into the back of eccentric cam hub  51 . A second bolt  531  is fitted parallel to bolt  543  but passes through washer  532  and bypasses cam  53  and passes through slot  513  on front of cam hub  51  and is fixed at the screw end with nut  533  which is fitted into the opposite end of slot  512 , opposite from bolt  543  nut  544 . When pressure on both bolts  543  and  531  is relieved the lever  54  can be rotated thereby lifting or dropping eccentrically the position of the cam over the hub. This adjustment is rotational on a curve and infinite in positions. Once desired position is achieved this position is locked in place by applying pressure on the assembly by simply turning bolts  543  and  531 . The effect of changing the relative position of the cam can change not only the position of the pedal footboard and the pedal beater but can also change the feel of the beater motion of the pedal. As the arc is affected by the eccentric motion of the cam the effect is to either accelerate or decelerate the speed at which the beater is impelled toward the drum head. This eccentric cam lever  54  adjusting cam  53  mounted on eccentric cam hub  51  is a new and unique way to adjust the stroke of a bass drum pedal and is one of the preferred embodiments of this invention.  FIG. 17  is a drawing showing an exploded view of the drive transmission assembly  50 , featuring eccentric cam adjustability.  FIG. 18  shows 4 drawings  18 A,  18 B,  18 C and  18 D.  FIG. 18A  shows the cam lever  54  adjusted in its down position.  FIG. 18B  shows cam lever  54  adjusted in its up most position.  FIG. 18C  is a perspective view of cam lever  54  showing the function area  549  that engages the cam lever stud  541 . Another view shown in  FIG. 18D  shows a side elevation detailing the function area  549  that engages the cam lever stud  541  and the hole  542  place off-centre the cam lever stud  541 . This shows graphically the function of the cam lever  54  lifting and dropping the cam  53 . Additional drawings in  FIG. 19A  and  FIG. 19B  show the back side of the eccentric hub and the relative positions of the nut  533  attached to cam anchor bolt  531  and nut  544  attached to cam lever bolt  543 . The smoothness of the curved shapes serves to make adjustment steps smooth and infinite. 
         [0054]    The spring-actuated return assembly (spring return)  70  shows in  FIG. 3  and  FIG. 6  and  FIG. 16 . and the spring-actuated return assembly  70  show in  FIG. 22  has one end connected to the Tower  20  at the bracketed protrusion  219  show in  FIG. 6  and the other end of the spring return  70  is connected to the drive transmission assembly  50  so as to return the drive transmission assembly  50  and the beater assembly  40  to their initial positions. The spring return  70  includes a first frame (spring rocker body)  71  connected to the driveshaft  23 L or  23 S and a second frame (spring bearing hanger)  72  which is rotatably connected to the spring rocker body  71  by a bearing  722 . A spring anchor assembly  73  is connected to the Tower  20  at slotted protrusion  219  and an extension spring  74  has one end connected to the spring anchor assembly  73  and the other end of the spring  74  is connected to the spring bearing hanger  72 . It is the spring bearing hanger  72  which is the focus of the preferred embodiment in the spring return assembly  70 . The bearing  722  is inserted into spring bearing hanger  72  which is cast in such a fashion as to allow the bearing to centre itself in the bottom of the casting without the internal turning area of the bearing to be impeding. The result is a completely unimpeded bearing which allows the bearing to perform without the friction that normal pedal designs inflict. This bearing holder, the spring bearing hanger  72  is monolithic in that is cast easily in one piece. Prior art shows capturing a bearing using two or more machined or cast pieces. The spring return  70  is rotationally adjusted and position on the end of the driveshaft  23 L or  23 S using screw  711  and nut  712  which is captured in a slot cast into the side of spring rocker body  71 . The spring bearing hanger  72  is attached to spring rocker body  71  with a threaded shaft  721  which passes through the captured bearing  722 . The bearing  722  is dropped into the bearing hanger  72  through an obliquely positioned open slot  723 . The spring return  70  can easily be disengaged from the tower body  21  because the anchor protrusion is slotted protrusion  219  and allows the spring anchor screw to be removed and attached without removing nut  735 . The shape of this anchor hole is 6 sided and accepts the hex shaped nut  735  to be locked in place thereby preventing turning from vibration which in turn would cause the spring settings to loosen. 
         [0055]      FIG. 2A  shows the single-Tower assembly  20  mounted on the left side. This is the preferred configuration for driving a beater pedal from the left. The operator has the opportunity to choose the position of the single-Tower to be placed either on the left or the right according to the operator&#39;s choice or need. 
         [0056]      FIG. 2B  shows that the drum pedal assembly of the present invention can also include one base-structure assembly  10  with two vertical towers, extending connected together by one bearing support. Choice can be made to use a longer drive shaft passing through a bearingless support or the drive shaft can be attached only to long drive shaft on the side that is chose to attach the drive transmission assembly  50 . 
         [0057]      FIG. 20  shows the drum clamping assembly  60 . Clamp  61  is attached to tower  20  shows in  FIG. 7  by passing mounting rod  612  through clamp mounting hole  611 . This creates a jawlike clamping device which attaches to a conventional bass drum counterhoop or other musical accessory attachment suitably disposed.  FIG. 21  shows 6 drawings,  21 A,  21 B,  21 C,  21 D,  21 E and  21 F.  FIGS. 21A and 21B  show the clamp lever in a raised position which to effects the closing of the clamp.  FIGS. 21C and 21D  show the clamp lever lowered to effect and unclamping which release pressure on the bass drum hoop or other device.  FIG. 21E  shows the plan view of the clamp to show angularity to enhance ease of access for the operator to reach the clamp lever screw  63 .  FIG. 21F  shows a cross-section drawing of the clamp assembly which illustrates the effect of the clamp lever screw as it is turned by the operator. As the screw  63  is turned clockwise, the lever  62  lifts, putting pressure against the base plate and thereby transmitting clamping pressure to the drum hoop or requisite attachment. The function of the clamp lever  62  is constitutes a preferred embodiment of the invention. 
         [0058]    While we have shown and described the preferred embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.