Abstract:
The method of drum structure formation that includes forming a strip of metal having an elongated edge into a counter hoop to be supported by a drum shell proximate the drum head, the forming including forming a reduced thickness strip bend proximate the hoop edge area.

Description:
This application is a continuation-in-part of pending U.S. application Ser. No. 13/317,810, filed Oct. 28, 2011. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to the construction of drums, where drum sticks are used to strike hoops on the drums. More particularly, it concerns methods of construction of such hoops to avoid problems arising in their use. 
     In the past, the configurations of drum hoops led to problems of hoop distortion during their bend-formation, and of drainage from under the hoops, and also to problems of interference with drums sticks, as during impact (rim shots). Such impact with hoop edges can cause severe damage to drum sticks. Also, water and other particles tended to accumulate under hoops. There is need for structural changes overcoming these and other problems and disadvantages. 
     Problems relating to distortion of such hoops during their construction and assembly, led to inaccuracy and difficulty in drum tuning. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide solutions to the above problems. Basically, the invention is embodied in drum structure formation, characterized by forming a strip of metal into a counter hoop to be supported by a drum shell proximate the drum head, and having a hoop shaped edge area formed to provide distortion free hoop structure and to resist or prevent drum stick damage, said forming including forming a reduced thickness bend proximate said edge area. 
     As will be seen, a gap is formed and located between the edge and the hoop side wall, the reduced thickness bend located at or near a hoop rolled outer surface spaced from the gap. The forming of reduced thickness is effected prior to forming of the strip of metal into hoop shape, and prior to forming of the bend, whereby resistance to hoop bending, and distortion, are reduced. Reduced thickness formation is effected by milling one side of the metal strip portion to be rolled. 
     Another object is to provide the rolled configuration extending toward the outer side of the hoop, for gap concealment. 
     Further objects include provision of a hoop flange to be spaced from and in offset relation to the reduced thickness area, and provision of sideward projections integral with the hoop, and spaced from the rolled edge, the projections defining openings for drum tensioning rods. 
     An advantage to a top rolled hoop of reduced thickness is that it enables distortion free hoop bending, and leaves a smooth rounded surface for the drummer to strike the drumstick, on and without causing damage to the stick. The standard drum counter hoop has a straight edge or just a slight radius that causes severe damage to the stick as it is struck. Another advantage is strength, provided by rolling the top edge of the hoop, which increases strength and distortion free stability of the hoop. A further advantage is provision of a hoop edge that is flat upon hoop bending. With the rolled edge adding strength, the hoop will tend to stay in such flat condition, even under high tension. 
     Yet another object is to provide a drum shell having a reduced thickness edge rolled toward the outer side of the hoop, reducing hoop distortion. 
     An important object is to provide a method of drum structure distortion free formation, that includes the following steps: 
     a) provide flat elongated strip of metal, 
     b) locally mill a side portion of strip to provide reduced thickness along an edge portion of strip, 
     c) deform the elongated strip to provide sideward tuning projections spaced from the reduced thickness ledge portion of strip, and also to form a seating edge for engagement with a drum head annular rim, 
     d) roll the reduced thickness edge portion of the elongated strip to thereby form an elongated drum stick engaged rolled edge portion, or bend, such thickness reduction characterized as sufficient to prevent distortion of the hoop, out of annularity and to prevent distortion of said tuning projections during said rolling, and hoop bending. 
     e) bend the thus formed metal strip into hoop shape. 
     These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: 
    
    
     
       DRAWING DESCRIPTION 
         FIG. 1  is a perspective view of a drum hoop embodying the invention; 
         FIG. 2  is a plan view of the  FIG. 1  hoop; 
         FIG. 3  is an edge view of the loop; 
         FIGS. 4 and 5  are enlarged fragmentary sections showing hoop construction; 
         FIGS. 4 b -4 c    are views showing processing of a hoop strip, prior to hoop formation; and 
         FIG. 6  shows a complete hoop, in section. 
     
    
    
     DETAILED DESCRIPTION 
     The drum hoop  10  has metallic construction, with walls  11  and  12  offset to receive a drum wall  18  therebetween, i.e. beneath shoulder  13 . Wall  12  has an upper edge  15  shaped to resist and prevent damage to a drum stick  17  which may at times impact that edge, during play. Edge  15  is shown, preferably, as rolled toward the outer side of the hoop, and to extend downwardly at  15   a . The reduced thickness edge terminal  15   c ′ faces inwardly toward wall  12 , below ledge  15   g  with a small gap or opening  16  located between  15   c ′ and wall  12 , for water drainage. Outer side of wall  12  is shown at  15   b . A typical thickness of wall  11  is about 2 millimeters. 
     Preferably, the edge portion  15   a  that is rolled is of substantially reduced thickness at t 1    FIG. 4 b   , leaving the main extent  12   a  of wall  12  of relatively un-reduced thickness at t 2 , below ledge  15   g , in  FIGS. 4 and 5 .  FIG. 4 b    shows the flat strip of material  15   c , and milling tool  90  positioned to remove material at  15   d  leaving reduced thickness t 1 . The length of  15   a  of reduced thickness between  15   f  and ledge  15   g  locates ledge  155 . Above the level of terminal  15   f . See also  FIG. 4 c   , showing hoop formation bending in direction  110 , about the hoop axis with substantially reduced resistance to bending being created due to reduced thickness at  15   a , with less hoop distortion during hoop formation. 
     Location of gap  16 , concealed and spaced below upper arcuate surface  15   e  and below ledge  15   g  prevents contact of the drum stick  17  with the terminal  15   f , and any sharp edge thereof. Also, ledge  15   g  located as shown enables the approximately 180° rolled metallic extent at  15 ,  15   a  and  15   n  to have substantially reduced thickness relation to wall  11 , to facilitate distortion free hoop formation. 
     A sideward projection  25  from the hoop provides an opening  113  for reception of a tensioning rod  21 , in outwardly spaced relation from the gap  16 . Space  112  between projection outer edge and through opening  113  that passes the tensioning rod, for tuning is kept constant. 
     A drum head is seen at  14 , and a drum axis at  32 . The method of drum distortion free formation includes the following steps: 
     a) provide flat elongated strip  15   c  of metal, 
     b) locally mill a side portion of strip with tool  90  to provide reduced thickness at  15   d  along an edge portion of strip, 
     c) deform the elongated strip to provide sideward tuning projections  25  spaced from the reduced thickness edge portion  15   a  of strip, and also to form a seating edge for engagement with a drum head annular rim  121 , 
     d) roll the reduced thickness edge portion of the elongated strip to thereby form an elongated drum stick engaged or engaging rolled and arcuate edge portion, or bend, as at  15   e , that thickness reduction characterized as sufficient to prevent distortion of the hoop out of annularity and to prevent distortion of the tuning projections  25  during such rolling, and hoop bending, 
     e) and bend the thus formed metal strip into hoop shape, with thickness reduction extending annularly. 
     Milling the metal strip  15   c  prior to forming the hoop bend ensures that there are no distortions on the underside, top and bottom of the flanged projections  25 , whereby they remain perpendicular to wall  12 , and distortion free. Accordingly, the distance “d” from the end of the flanged ear or projections to the edge of the oval hole  113  that passes the tensioning rod  212  is consistently the same, at all of the flanged ears  25  around the hoop. The configuration of the channel ledge  120  where the drum head  14  seats, is also consistently the same, around the hoop, whereby tuning of the drum is very simply optimized, and a true hoop configuration is achieved.  FIG. 6  shows a completely formed hoop, in section.