Patent Publication Number: US-11640814-B1

Title: Suspension system for a drum

Description:
FIELD 
     The present invention is directed to a suspension system for drum, and more particularly, to a suspension system that is configured to support a drum in a balanced manner 
     BACKGROUND 
     When the drum head of a drum (e.g., a tom-tom drum) is tuned with precisely even tension and the drum shell keeps is perfect roundness, the drum is supposed to make the best tone and sustain of sound. However, in the majority of cases, the drums are installed with mounts that deform the drum heads and drum shell. The deformation that makes the sound worse is caused by the drum being unbalanced. 
     U.S. Pat. No. 4,158,980 discloses a mounting bracket for a drum. With reference to  FIG.  1 A , no moment force is created when the mounting bracket (not shown) is installed and the drum  10  is oriented horizontally, since the mounting support locations L are on a plane P oriented along the center of gravity C of the drum  10 . However, with reference to  FIG.  1 B , when the mounting bracket is installed and the drum  10  is oriented at an angle with respect to horizonal, mounting support locations L are no longer on a plane oriented along the center of gravity C of the drum  10 . Thus, a moment force F is generated due to the weight of the drum  10  and the drum is thus unbalanced. 
     Therefore, a need exists for a suspension for a drum that ensures balance of the drum no matter how the drum is oriented upon mounting. 
     SUMMARY 
     An aspect of an embodiment provides a suspension system for a drum. The drum has a cylindrical drum shell, upper and lower drum heads fitted over respective first and second opposing ends of the drum shell, upper and lower drum hoops on the shell and retaining the respective upper and lower drum heads to the shell, upper and lower of lugs fixed to portions of a periphery of the drum shell, and a plurality of adjustable upper and lower tensioning rods securing the respective upper and lower drum hoops to the respective upper and lower lugs. Certain pairs of tensioning rods are disposed 180 degrees apart with regard to a circumference of the drum. The suspension system includes upper and lower suspension structures each configured to surround a portion of a circumference of the drum when mounted thereon near the respective upper and lower drum hoops. Each of the upper and lower suspension structures has at least one distal end with each distal end having a mounting hole thereby defining a mounting hole pair including at least one upper mounting hole in the upper suspension structure and at least one lower mounting hole in the lower suspension structure such that the at least one lower mounting hole is disposed 180 degrees apart from the at least one upper mounting hole. The at least one upper mounting hole is configured to receive at least one tensioning rod of a certain pair of tensioning rods, and the at least one lower mounting hole is configured to receive the other tensioning rod of the certain pair of tensioning rods. A connection structure is mounted between the upper and lower suspension structures and is configured for adjusting a spacing between the upper and lower suspension structures. The connection structure has clamping structure including an adjustable opening configured to receive a holding rod and to clamp upon and hold the holding rod in fixed relation with respect to the connection structure. A vibration isolation member is removably disposed in the at least one upper mounting hole and the at least one lower mounting hole to define support locations to support the drum when installed with respect to the suspension structures. Each vibration isolation member has a bore there-through for receiving a tensioning rod, and are configured to isolate vibration between the drum and the suspension structures. 
     When the suspension system is mounted to the drum by each mounting hole and associated vibration isolation member receiving an associated tensioning rod at a support location, the vibration isolation member mounted in the at least one upper mounting hole is configured to engage a downwardly facing surface of the upper drum hoop and the vibration isolation member mounted in the at least one lower mounting hole is configured to engage a downwardly facing surface of a lower lug to support weight of the drum upwardly. The suspension system is constructed and arranged to prevent a moment force on the drum when the drum is oriented in a horizontal position and in a position angled with respect to the horizontal position due to the support locations being oriented to be balanced with respect to a center of gravity of the drum. 
     Other aspects of the embodiments, including apparatus, articles, methods, systems, assemblies, and the like which constitute part of the invention, will become more apparent upon reading the following detailed description of the exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are incorporated in and constitute a part of the specification. The drawings, together with the general description given above and the detailed description, serve to explain the principles of the invention. In such drawings: 
         FIG.  1 A  is a schematic view of a conventional drum showing a plane of mounting support locations along a center of gravity of the drum when the drum is in a horizonal orientation; 
         FIG.  1 B  is a schematic view of the drum of  FIG.  1 A , but showing the plane of mounting support locations no longer along a center of gravity of the drum and a generated moment force on the drum when the drum is oriented at an angle with respect to horizontal; 
         FIG.  2    is a perspective view of a suspension system in accordance with a first exemplary embodiment of the present disclosure, shown mounted to a drum; 
         FIG.  3    is an exploded view of the suspension system of  FIG.  2   ; 
         FIG.  4    is a plan view of an upper suspension structure of the suspension system of  FIG.  3   , showing mounting holes offset from a circumferential direction; 
         FIG.  5 A  is an enlarged exploded sectional view of a vibration isolation member of the suspension system of  FIG.  3   , shown with a cooperating, optional spacer; 
         FIG.  5 B  is cross-sectional view of the vibration isolation member and spacer of  FIG.  5 A ; 
         FIG.  5 C  is a partial sectional view of the spacer provided between a flanged metal hoop and the vibration isolation member of an embodiment; 
         FIG.  6    is a perspective view of a suspension system having a clamping structure in accordance with a second exemplary embodiment for receiving an L-arm; 
         FIG.  7    is a side view of the suspension system of  FIG.  2   , shown mounted to a drum at four support locations; 
         FIG.  8 A  is a schematic view of the drum of  FIG.  7    showing a plane of the four support locations along a center of gravity of the drum when the drum is in a horizonal orientation; 
         FIG.  8 B  is a schematic view of the drum of  FIG.  7   , showing the plane of four support locations along a center of gravity of the drum when the drum is oriented at an angle with respect to horizontal; 
         FIG.  9    is a side view of the suspension system of  FIG.  2   , shown mounted to a drum at two support locations; 
         FIG.  10 A  is a schematic view of the drum of  FIG.  9    showing a plane of the two support locations along a center of gravity of the drum when the drum is in a horizonal orientation; 
         FIG.  10 B  is a schematic view of the drum of  FIG.  9   , showing the plane of the two support locations along a center of gravity of the drum when the drum is oriented at an angle with respect to horizontal; 
         FIG.  11    is a side view of the suspension system of  FIG.  2   , shown mounted to a drum at three support locations; 
         FIG.  12    is a front perspective view of the support system  FIG.  2    mounted on a drum, showing rubber spacers installed between an upper suspension structure and an upper hoop and between a lower suspension structure and lugs; 
         FIG.  13    is a perspective view of a suspension system in accordance with a second exemplary embodiment of the present disclosure, shown mounted to a drum; 
         FIG.  14    is an exploded view of the suspension system of  FIG.  13   ; 
         FIG.  15    is a side view of the suspension system of  FIG.  13   , shown mounted to a drum at four support locations; 
         FIG.  16    is a side view of the suspension system of  FIG.  13   , shown mounted to a drum at two support locations; and 
         FIG.  17    is a side view of the suspension system of  FIG.  13   , shown mounted to a drum at three support locations. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the invention. It should be noted, however, that the invention in its broader aspects is not necessarily limited to the specific details, representative materials and methods, and illustrative examples shown and described in connection with the exemplary embodiments. 
       FIG.  2    is a perspective view of a suspension system, shown generally indicated at  12 , in accordance with a first exemplary embodiment of the present disclosure, shown mounted to a drum  10 , such as a tom-tom drum. The drum  10  is conventional and has a cylindrical drum shell  14 . An upper drum head  16  and a lower drum head (not visible) is fitted over respective first and second opposing ends of the drum shell  14 . An upper drum hoop  18  retains the upper drum head  16  on the shell  14  and a lower drum hoop  20  retains the lower drum head on the shell  14 . Upper lugs  21  and lower lugs  21 ′ are fixed to portions of a periphery of the drum shell  14 . A plurality of adjustable upper tensioning rods  22   a ′,  22   a ″ secure the upper drum hoop to upper lugs  21 , and a plurality of adjustable lower tensioning rods  22   b ′,  22   b ″ secure the lower drum hoop to lower lugs  21 ′. Certain pairs of tensioning rods (e.g., rod pairs  22   a ′,  22   b ′; rod pairs  22   a ″,  22   b ″) are disposed 180 degrees apart with regard to a circumference of the drum  10 , on opposing sides of the drum  10 , as will be explained more fully below. 
     With reference to  FIGS.  2  and  3   , the suspension system  12  includes an upper suspension structure  24  and a lower suspension structure  26 , each configured to surround a portion of a circumference of the drum  10  when mounted thereon near the respective upper and lower drum hoops  18 ,  20 . Each of the upper and lower suspension structures  24 ,  26  is the form of a flat arcuate plate of identical configuration. For manufacturing ease, each upper and lower suspension structures  24 ,  26  can be of two part configuration. 
     As shown in  FIG.  3   , each of the upper and lower suspension structures  24 ,  26  has a pair of distal ends  28 . Each distal end  28  of the upper suspension structure  24  has an upper mounting hole therein. One mounting hole  30  in the upper suspension structure  24  and one mounting hole  30 ′″ in the lower suspension structure  26  that is disposed 180 degrees apart from the one mounting hole  30  in the upper suspension structure  24  define mounting holes pairs. It is noted that when upper and lower suspension structures are mounted to the drum  10 , mounting hole  30  is at an upper portion of the drum  10 , while mounting hole  30 ′″ is located at a lower portion of the drum. Another set of mounting hole pairs is defined by mounting holes  30 ′ and  30 ″, such that when upper and lower suspension structures  24 ,  26  are mounted to the drum  10 , mounting hole  30 ′ is at an upper portion of the drum  10 , while mounting hole  30 ″ is located at a lower portion of the drum. Thus, as shown in  FIG.  2   , mounting hole  30  is configured to receive tensioning rod  22   a ′, the mounting hole  30 ′″ is configured to receive tensioning rod  22   b ′, mounting hole  30 ′ is configured to receive tensioning rod  22   a ″, and mounting hole  30 ″ is configured to receive tensioning rod  22   b ″. 
     With reference to  FIG.  4   , each mounting hole  30 ,  30 ′,  30 ″ and  30 ′″ is in the form of an elongated slot so as to not be parallel to another slot of each suspension structure  24 ,  26 . Thus, the offset slots prevent slip of the suspension system  12  when mounted on the drum  10 , even when the drum  10  is tilted in the circumferential direction A. Also, the width of the slots accommodates variation of tensioning rod position due to manufacturing tolerances or tensioning rods provided by different drum manufacturers. Thus, the symmetrically angled slots permit changeable pitch/distance of two mounting locations. 
     As shown in  FIGS.  2  and  3   , each of the upper and lower suspension structures  24 ,  26  includes a pair of secondary mounting holes  32  spaced from the distal ends  28  and constructed and arranged to receive an associated tensioning rod  22   a ′″ or  22   b ′″ in a floating manner Each of the upper and lower suspension structures  24 ,  26  optionally includes a reinforcement plate  34  fixed thereto to reinforce the associated suspension structure  24 ,  26 . Each reinforcement plate is arc-shaped to correspond with a portion of the arc-shaped suspension structure  24 ,  26 . Each reinforcement plate  34  includes secondary mounting holes  32 ′ that correspond with an associated mounting hole  32 . Each of the mounting hole pairs  32 ,  32 ′ includes a rubber insert  35  that receives an associated tensioning rod in a flotating manner The rubber insert  35  prevents any metal to metal contact between a tensioning rod and suspension structure  24 ,  26 . 
     With reference to  FIGS.  2  and  3   , a rubber vibration isolation member  36 , is removably disposed in the at least one upper mounting hole, e.g., hole  30 ′ and the at least one lower mounting hole e.g.,  30 ″ to define support locations and support the drum  10  when installed with respect to the suspension structures  24 ,  26 , as will be explained more fully below. In the illustrated embodiment, each of the upper mounting holes  30 ,  30 ′ and each of the lower mounting holes  30 ″,  30 ′″ includes a vibration isolation member since, as shown in  FIG.  2   , the drum  10  is supported at four support locations. 
     As best seen in the enlarged views of  FIGS.  5 A and  5 B , each vibration isolation member  36  has a bore  38  there-through for receiving a tensioning rod; a bottom portion  40  configured to engage surfaces of a mounting hole  30 ,  30 ′,  30 ″,  30 ′″, and having a generally planar upwardly facing surface  41  for engaging an downwardly facing surface  43  of an associated suspension support structure  24 ,  26 ; a central portion  42  having a generally planar downwardly facing surface  44  for engaging an upwardly facing surface  46  of an associated suspension support structure  24 ,  26 ; a top portion  48  having an upwardly facing surface  50  for engaging a portion of the drum hoop  18  (e.g., a die cast hoop), and a bellows  51 , generally adjacent to surface  50  and between the top portion  48  and central portion  42  to permit the vibration isolation member  36  to buckle easily. Each vibration isolation member  36  is configured so that the central portion  42 , the bellows  51  and top portion  48  thereof extend beyond the upwardly facing surface  46  of the suspension structures  24 ,  26 . 
     In the embodiment of  FIGS.  5 A and  5 B , the upwardly facing surface  50  is planar so as to engage a planar surface  52  ( FIG.  7   ) of the upper drum hoop  18  when the drum hoop is a die-cast hoop. With reference to  FIG.  5 C , when the upper drum hoop  18  is of the flanged metal hoop  18 ′ type, an additional rubber spacer  53  ( FIGS.  5 A,  5 B ) is provided, having a through bore  54  that aligned with bore  38  of the vibration isolation member. A downwardly facing surface  56  of the spacer  53  is planar and rests on surface  50  of the vibration isolation member  36 . An upper surface  58  of the spacer  53  engages a downwardly facing surface of the flanged metal hoop  18 ′. The spacer  53  can be considered to be part of the vibration isolation member  36  (made integral therewith) and can be used with any flanged metal hoop such as, but not limited to, a double flange hoop, a triple flange hoop, or any other flanged metal hoop that would require the spacer  53 . 
     Returning to  FIG.  3   , the suspension system  12  includes a connection structure, generally indicated at  60 , that is adjustably mounted between the upper and lower suspension structures  24 ,  26 . In the embodiment of  FIG.  3   , the upper suspension structure  24  is fixed to an upper portion  61  of the connection structure  60  via threaded fasteners  62  engaging threaded bores  64  in the upper portion  61  of the connection structure  60 . A pair of shafts  66  are secured to the lower suspension structure  26 , via threaded fasteners  62 ′ engaging threaded bores  67  in the shafts  66 , so as to extend vertically upward. The connection structure  60  includes a pair of shaft-receiving bores  68 , each receiving an associated shaft  66 . A pair of set screws  69 , as securing members, are engaged in threaded bores  70  in the connection structure  60  to adjustably secure the shafts  66  to the connection structure  60 . Thus, a distance between the upper and lower suspension structures  24 ,  26  can be adjusted by sliding the connection structure  60  along the shafts  66 . An optional support plate  72  can be provided between the shafts  66  and the lower suspension structure  26 . 
     The connection structure  60  has clamping structure, generally indicated at  74 , that can be of the type disclosed in U.S. Pat. No. 4,141,272, the entire content of which is hereby incorporated by reference into this disclosure. Thus, the clamping structure  74  includes an adjustable opening  76  configured to receive a holding rod  78  ( FIG.  2   ) and to clamp upon and hold the holding rod  78  in fixed relation with respect to the connection structure  60 . The clamping structure  74  also comprises a first clamp member  80  fixed to the connection structure  60  and a second clamp member  82  affixed via a hinge  84  with the first clamp member  80 . The first and second clamp members  80 ,  82  define the adjustable opening  76 . A threaded fastener  86  disposed through the second clamp member  82  and is threadedly engaged with the first clamp member  80  so that tightening of the fastener  86  via handle  87  moves the second clamp member  82  with respect to the first clamp member  80  to reduce a size of the adjustable opening  76  and thus clamp on the holding rod  78 . 
     In the embodiment of  FIGS.  2  and  3   , the clamp members  80 ,  82  are configured to define opening  76  so as to receive a standard ⅞″ holding rod  78  in a horizontal manner However, with reference to  FIG.  6   , it can be appreciated that the clamp members  80 ′,  82 ′ can be provided to define the opening  76 ′ so as to receive a conventional L-arm  78 ′ (holding rod) in a vertical manner 
     Each vibration isolation member  36  is configured to isolate vibration between the drum  10  and the suspension structures  24 ,  26  at support locations.  FIGS.  2  and  7    show four support locations at tensioning rods  22   a ′,  22   a ″,  22   b ′ and  22   b ″ and respective mounting holes  30 ,  30 ′,  30 ′″ and  30 ″, each having a vibration isolation member  36  therein;  FIG.  9    shows two support locations at tensioning rods  22   a ″,  22   b ″ respective mounting holes  30 ′ and  30 ″, each having a vibration isolation member  36  therein; and  FIG.  11    shows three support locations at tensioning rods  22   a ″,  22   b ′ and  22   b ″ and respective mounting holes  30 ′,  30 ′″ and  30 ″, each having a vibration isolation member  36  therein. Thus, the minimal amount of support locations is two. When the suspension system  12  is mounted to the drum  10  with each mounting hole  30 ′ and  30 ″ and associated vibration isolation member  36  receiving a respective tensioning rod  22   a ″,  22   b ″ at a support location, with reference to  FIG.  9   , at one side of the drum, the upwardly facing surface  50  of the vibration isolation member  36  mounted in one upper mounting hole  30 ′ at tensioning rod  22   a ″ is configured to engage the downwardly facing surface  52  of the upper die cast drum hoop  18  and on the opposing side of the drum, the upwardly facing surface  50  of the vibration isolation member  36  mounted in one lower mounting hole  30 ″ at tensioning rod  22   b ″ is configured to engage a downwardly facing surface  37  of a lower lug  21 ′ to support weight of the drum  10  upwardly. In  FIG.  9   , the upper mounting hole  30  associated with the tensioning rod  22   a ′ and the lower mounting hole  30 ′″ associated with tensioning rod  22   b ′ each includes a rubber insert  35  since these are not support locations. Thus, the suspension system  12  is constructed and arranged to prevent a moment force on the drum  10  when the drum is oriented in a horizontal position (see  FIG.  10 A  for two support locations and  FIG.  8 A  for four support locations) and in a position angled with respect to the horizontal position (see  FIG.  10 B  for two support locations and  FIG.  8 B  for four support locations) due to the support locations being oriented along a plane P of the center of gravity C of the drum  10  and thus balanced with respect to the center of gravity C. Prevention of a moment force also results when three support locations are used as in  FIG.  11   . 
     With the drum  10  is used in a live concert, some sound engineers do not like too much sustain. With reference to  FIG.  12   , when time for a sound check is limited, a split-ring rubber spacer  88  can be placed about one or more tensioning rod  22   a ′″ (non-support locations) between the drum hoop  18  and the upwardly facing surface  46  of the upper suspension structure  24  and/or a split-ring rubber spacer  88 ′ can be placed about one or more tensioning rods  22   b ′″ (non-support locations) between the downwardly facing surface  37  of a lower lug  21 ″ and the upwardly facing surface  46  of the lower suspension member  26 . By adjusting the spacer  88 ,  88 ′ (one to four can be used), one can instantly change the characteristics of the suspension system  12  and adjust the sound of the drum  10 . 
     With reference to  FIGS.  13  and  14   , a second embodiment of a suspension system  12 ′ is shown that configured to support the drum  10  at four support locations. The suspension system  12 ′ includes an upper suspension structure, generally indicated at  24 ′ and a lower suspension structure, generally indicated at  26 ′. Each of the upper and lower suspension structures  24 ′,  26 ′ includes a pair of support rods  90 . As best shown in  FIG.  14   , each support rod  90  includes a first, generally arcuate portion  92  having an eye bolt  94  couped to the distal end  96  of the first portion  92  thereof. Each eyebolt  94  defines a mounting hole. One mounting hole  30  in the upper suspension structure  24 ′ and one mounting hole  30 ′″ in the lower suspension structure  26 ′ that is disposed 180 degrees apart from the one mounting hole  30  in the upper suspension structure  24 ′ define mounting holes pairs. Another set of mounting hole pairs is defined by mounting holes  30 ′ and  30 ″. Thus, as shown in  FIG.  13   , mounting hole  30  is configured to receive tensioning rod  22   a ′, the mounting hole  30 ′″ is configured to receive tensioning rod  22   b ′, mounting hole  30 ′ is configured to receive tensioning rod  22   a ″, and mounting hole  30 ″ is configured to receive tensioning rod  22   b ″. In the embodiment of  FIGS.  13 - 14   , each mounting hole includes an associated vibration isolation member  36  therein. 
     Each support rod  90  also includes a second, linear portion  98  disposed generally 90 degrees with respect to the first portion  92 . The connection structure  60 ′ includes bores  100  therein, with ends  102  of each second portion  98  of each support rod  90  being adjustably received in an associated bore  100  to thereby adjust a spacing between the upper and lower support structures. Each support rod  90  can also be adjusted for rotation. A securing member  104 , preferably in the form of a set screw secures each second portion  98  of each support rod  90  to the connection structure  60 ′. The connection structure  60 ′ has clamping structure, generally indicated at  74 , that is identical to that of  FIG.  3   . It can be appreciated that the clamping structure  74  can be of the type for an L-rod as in  FIG.  6   . 
     As shown in  FIG.  13   , each support rod  90  is configured to surround a portion of a circumference of the drum  10  when mounted thereon near the respective upper and lower drum hoops  18 ,  20 . As shown, each support rod  90  is configured to pass over the lugs  21 ″. 
     Each vibration isolation member  36  is configured to isolate vibration between the drum  10  and the suspension structures  24 ′,  26 ′ at a support location.  FIGS.  13  and  15    show four support locations at tensioning rods  22   a ′,  22   a ″,  22   b ′ and  22   b ″ and respective mounting holes  30 ,  30 ′,  30 ′″ and  30 ″, each having a vibration isolation member  36  therein. Thus, all four support rods  90  are needed.  FIG.  16    shows two support locations at tensioning rods  22   a ″ and  22   b ″ and respective mounting holes  30 ′ and  30 ″, each having a vibration isolation member  36  therein. Thus, only two support rods  90  are needed.  FIG.  17    shows three support locations at tensioning rods  22   a ″,  22   b ′ and  22   b ″ and respective mounting holes  30 ′,  30 ′″ and  30 ″, each having a vibration isolation member  36  therein. Thus, only three support rods  90  are needed. Hence, the minimal amount of support locations and support rods  90  is two. When the suspension system  12 ′ is mounted to the drum  10  with each mounting hole  30 ′ and  30 ″ and associated vibration isolation member  36  receiving a respective tensioning rod  22   a ″,  22   b ″ at a support location, with reference to  FIG.  16   , the upwardly facing surface  50  of the vibration isolation member  36  mounted in one upper mounting hole  30 ′ at tensioning rod  22   a ″ is configured to engage a downwardly facing surface  52  of the upper die cast drum hoop  18  and the upwardly facing surface  50  of the vibration isolation member  36  mounted in one lower mounting hole  30 ″ at tensioning rod  22   b ″ is configured to engage a downwardly facing surface  37  of a lower lug  21 ′ to support weight of the drum  10  upwardly. Thus, the suspension system  12 ′ is constructed and arranged to prevent a moment force on the drum  10  when the drum is oriented in a horizontal position and in a position angled with respect to the horizontal position due to the support locations being oriented along a plane P of the center of gravity C of the drum  10  and thus balanced with respect to the center of gravity C in the manner disclosed above with regard to  FIGS.  8 A,  8 B,  10 A and  10 B . This is true when two, three, or four support locations are used. 
     Thus, the suspension systems  12 ,  12 ′ advantageously does not cause drum head deformation and thus ensures balance of the drum  10  no matter how the drum is oriented upon mounting. 
     The foregoing detailed description of the certain exemplary embodiments has been provided for the purpose of explaining the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. This description is not necessarily intended to be exhaustive or to limit the invention to the precise embodiments disclosed. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way.