Patent Publication Number: US-6222108-B1

Title: Percussion amplitude adjustable pedal drum-beating device

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to a pedal drum-beating device, more particularly, it relates to a percussion amplitude adjustable pedal drum-beating device, in which a flywheel can be certainly and rapidly locked on a rotation shaft. 
     A percussion drum, among other musical instruments, is used to provide more distinct beats in performance of a concert. A conventional pedal drum-beater shown in FIG. 1 is provided with a rotation shaft, whereon a drum-beater and an interactive flywheel device are arranged; and a drive chain wound on the flywheel device is coupled to a free end of a pedal with its one end so that a drum is stricken by tramping the pedal drum-beater via the drive chain and the flywheel device. The flywheel device composed of a flywheel and two clutch pieces is locked on the rotation shaft by two fixing studs (shown in FIG.  2 ), and a positioning ferrule is inserted between those two clutch pieces and the rotation shaft. However, a percussion amplitude adjustable structure formed as abovesaid may cause occasional race rotation attributable to the loose clamp of the clutch pieces onto the positioning ferrule because of its slippery outer face. 
     In view of abovesaid defect, this invention is proposed with an improved design for clamping a flywheel firmly to a rotation shaft by pivotally jointing tail end of a main body and a clutch piece together and locking the other end with a single fixing stud, and forming a row teeth on a positioning ferrule to create beats positively and reliably. 
     SUMMARY OF THE INVENTION 
     The primary object of this invention is to clamp a flywheel firmly on a rotation shaft. 
     Another object of this invention is to clamp a clutch piece firmly on a positioning ferrule for prevention of any slip phenomenon between the positioning ferrule and the rotation shaft. 
     In order to realize the abovesaid objects, a flywheel comprising a main body and a clutch piece is pivotally disposed on a rotation shaft, wherein the tail end of the main body and the clutch piece are pivotally jointed while their other ends are kept open. A fixing stud is used to lock the main body and the clutch piece to form a unified assembly, and a positioning ferrule is disposed in-between the main body and the clutch piece. Moreover, a row of teeth is formed on the positioning ferrule, which is provided with an axial open channel at its one end. By proper assembly of foregoing components of this invention, a lever structure is formed to realize a rapid and dependable attachment on the rotation shaft and without slipping. 
     A detailed description of this invention together with further advantages or features thereof, at least an example of a preferred embodiment thereof will be described below with reference to the annexed drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The related drawings in connection with the detailed description of this invention to be made later are described briefly as follows in which: 
     FIG. 1 is a perspective view of a conventional pedal device; 
     FIG. 2 is an exploded perspective exploded view of a conventional percussion amplitude adjustment structure; 
     FIG. 3 is an exploded perspective exploded view of this invention; 
     FIG. 4 is an assembled perspective assembled view of this invention; 
     FIG. 5 is a cutaway sectional view taken along line  5 — 5  in FIG. 4; and 
     FIG. 6 is a schematic application view of this invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As shown in FIG.  3  through FIG. 6, this invention is assembled on a rotation shaft  13  of a pedal base  10  including a foot pedal  11  and a drum-beater  12 , wherein a flywheel device  20  is pivotally disposed on the rotation shaft  13 . 
     The flywheel device  20  is composed of a main body  21  and a clutch piece  22 , wherein a semi-circular receptacle  211 ,  221  is formed oppositely in the main body  21  and the clutch piece  22  respectively; a split positioning ferrule  30  is arranged in the semi-circular receptacles  211 ,  221 ; pair of corresponding pin sleeves  212 ,  222  are formed at a tail end of the main body  21  and the clutch piece  22  respectively; and, the sleeves  212 ,  222  are pivotally combined by inserting a positioning pin  23  therethrough to form a hinge structure. The front end of the main body  21  and the clutch piece  22  are open, and wherein a screw hole  213  is formed in the front end of the main body  21  for accommodating a screw nut  26 , and a tapped hole  223  is formed in the front end of the clutch piece  22  at a position corresponding to the screw hole  213  for receiving a fixing stud  24  to lock the main body  21  and the clutch piece  22  into a unified assembly. Besides, a guide channel  214  for maintaining a drive chain  25  in place encircles the circumference of the main body  21 , and one end of the drive chain  25  is coupled with the front end of the foot pedal  11 . 
     Moreover, a plurality of row teeth  31  is aligned annularly on the circumference of the split positioning ferrule  30 , which is further provided axially with an open channel  32  for receiving and clamping the rotation shaft  13  by the body  21  and the clutch piece  22   30  and the rotation shaft  13  firmly. 
     In this invention constructed by abovesaid components, the sleeves  212 ,  222  and the positioning pin  23  are used to pivotally combine the main body  21  with the clutch piece  22 . After the positioning ferrule  30  is disposed in the semi-circular receptacles  211 ,  221 , the fixing stud  24  is inserted through the screw hole  213  and fixed in the screw nut  26  to form a lever structure for stably clamping on the positioning ferrule  30 . In addition, the open channel  32  and the row teeth  31  facilitate to the fixing stud  24  for clamping this invention on the rotation shaft  13 . Thus, the pedal  11  is tramped to drive the drum-beater  12  to strike the drum through the drive chain  25 , the flywheel device  20 , and rotation shaft  13 . 
     According to abovesaid, the merits of this invention may be summarized as the following: 
     1. By using the sleeves  212 ,  222  and the positioning pin  23  to pivotally join the tail end of the main body  21  with that of the clutch piece  22  and using the fixing stud  24  to lock another open end of the main body  21  and that of the clutch piece  22  to form a lever structure, this invention can clench and lock the split positioning ferrule  30  firmly around shaft  13  with ease. 
     2. The open channel  32  is helpful in engaging the positioning ferrule  30  with the rotation shaft  13  when locking. 
     3. The teeth  31  are helpful in engaging the main body  21  and the clutch piece  22  onto the positioning ferrule  30  for prevention of any possible slip phenomenon. 
     4. When adjustment of percussion amplitude is desired, all a user has to do is release the fixing stud  24 , then swivel the fixing stud  24  to lock again after adjustment. This simple procedure is far more convenient than a conventional device, without need imbalance of those two fixing studs, the slippery outer face of the positioning ferrule, etc that may cause slip page between the flywheel and the rotation shaft. 
     Although, this invention has been described in terms of a preferred embodiment, it is apparent that numerous variations and modifications may be made without departing from the true spirit and scope thereof, as set forth in the following claims.