Patent Publication Number: US-7220905-B2

Title: Strainer for a snare drum

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention is directed to a strainer for use with a drum, in particular to a strainer for use with a snare drum, where the strainer includes a positive locking mechanism. 
   2. Description of the Related Art 
   Snare drums typically include a plurality of wires, or snares, which contact a bottom drumhead of the snare drum so that the snares are vibrated by the vibration of the bottom drumhead when the snare drum is played. A strainer is typically used to tension the snares in order to change the tone produced by the drum by changing the position of the snares so that they are either in contact or not in contact with the drumhead. Snare tension may also be fine tuned or finely adjusted by a tension knob which is rotated to finely tune the tension in the snare to change the tone produced by the drum. 
   Conventional strainers for snares use a lever directly connected to a piston, wherein the lever pivots about an axis generally perpendicular to the piston, so that when the lever is pivoted from one position to another, the piston drops and the tension in the snares is released so that the snares are no longer in contact with the drumhead. Some of these pivoting lever for strainers can only be operated so that the snares are either in contact with the drumhead (snares-on mode), or not in contact with the drumhead (snares-off mode), and are not adjustable to different tensions in between. Further, the strainer tends to be tensioned or released quickly, so that the snares make an unwanted “throw-off” noise against the drumhead, which is very undesirable, particularly for orchestral musicians. Other prior art systems permit intermediate adjustment of the snare tension between the snare-on and snare-off modes using the strainer. 
   However, strainer levers of the prior art systems may become accidentally dislodged because they do not have any positive lock mechanism; therefore, the levers can accidentally vibrate loose and disengage to the off position during vigorous play. 
   The need exists for a system and assembly for positively locking the strainer lever and/or tension knob to prevent slippage or disengagement during performance or play. 
   SUMMARY OF THE INVENTION 
   A strainer for a snare assembly is adapted to be attached to a percussion instrument, the strainer comprising a tensioning mechanism for applying a tension to snares of a percussion instrument; a lever having a first end and a second end, the lever being pivotably mounted to the tensioning mechanism, whereby pivoting the lever changes a position of the tensioning mechanism to change the tension in the snares; and a positive locking mechanism to positively lock said lever in at least one of a plurality of snare tensioning positions. The positive lock mechanism mechanically connects the lever to a body portion fixedly mounted to the percussion instrument. 
   In the preferred embodiment, the positive locking mechanism comprises a movable button that is movable relative to the lever to change the positive locking mechanism from a locking condition where the lever is blocked against pivotal rotation relative to said body portion to an unlocking condition where the lever is free to pivot with respect to the body portion. 
   The invention may employ a hook-style latch disposed on the main body portion fixed to the drum shell and a locking pawl disposed on the movable button, whereby the locking pawl selectively mates with the hook-style latch to achieve the locking condition. When an operator pushes the movable button, the locking pawl is disengaged from the hook-style latch. Of course, the invention should not be limited to the specific structure shown in the drawings or described herein. 
   The structural and functional benefits of the present invention will be apparent to those of skill in the art when viewed in light of the following description and the accompanying drawings, which are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the snare drum and strainer assembly of this present invention. 
       FIG. 2  is a front view of the strainer according to the present invention shown in the snare-on position. 
       FIG. 3  is a front view of the strainer according to the present invention shown in the snare-off position. 
       FIG. 4  is a partial cross sectional view of the strainer of  FIGS. 2 and 3  showing the internal piston member and bearing system. 
       FIG. 5  is a cross sectional view of the lever and positive lever locking mechanism sown in  FIGS. 2 and 3  shown in the locked position. 
       FIG. 6  is a cross sectional view of the lever and positive lever locking mechanism sown in  FIGS. 2 and 3  shown in the unlocked position. 
       FIG. 7  is a partial cross sectional view of the strainer of the present invention. 
       FIG. 8  is a partial cross sectional view of the strainer of  FIG. 7  taken along section line VIII-VIII. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
   With reference to  FIG. 1 , the strainer  10  of this invention is shown mounted to docking stations (not shown) bolted to the drum shell. Attachment bolts  11 ,  12  preferably have a drum key head thus making the strainer  10  easy to remove with a conventional drum key with the strings and snares still attached to the strainer  10 . This allows the bottom head of the drum to be changed without altering the setting of the snares. After the bottom head of the drum is replaced, the strainer  10 , also referred to as a throw-off, can be reattached to the drum and the snares will be perfectly set and aligned as before removal. 
   The strainer  10  is shown in an isolated drawing in  FIGS. 2 and 3 .  FIG. 2  shows the strainer  10  in a snare-on position, and  FIG. 3  shows the strainer  10  in the snare-off position. The strainer  10  comprises a main body  20  mountable to the drum shell through attachment bolts  11 ,  12 ; a piston member  30  sandwiched between two shell members of the main body  20 ; and a lever  40  that is cammingly engageable with the piston member  30 . Thus, the piston  30  is retained within the main body  20  connected to the shell so that the piston member  30  may reciprocate relative to the shell. As the lever  40  is pivoted in the direction of arrow ‘A’ shown in  FIG. 2 , the piston member  30  will move in a downward direction and, as a result, the snare clamp  34  moves to adjust the tension on the snares. 
   Typically, snares are operably connected to piston member  30  by the snare clamp  34  in a manner that is well known to those of skill in the art. 
     FIG. 4  shows the piston member  30  and main body  20  with bearing members  25  in the form of steel balls disposed between the main body  20  and the piston member  30 . Although two such ball bearing members  25  are shown on each side of the piston member  30 , it may be preferable to include a different number of these bearing members  25 ; it has been shown that two bearing members  25  may be a preferred design. Additionally, a low-friction bearing plate may be used in the places of the ball bearing member  25 . The low-friction bearing plates or bearing members  25  reduce side-by-play of the piston member  30  and provide a smoother camming action during use. 
   With reference to  FIGS. 5-6 , the present invention further provides a positive lever locking mechanism. Specifically, the lever  40  is assembled with a push-button release member  42  that is spring biased by a resilient member  44 . The positive lever locking mechanism is provided by a hook-type latch  23  fixedly mounted on the main body  20  and the sliding pawl  43  of the release member  42 . 
   When the positive lever locking mechanism is in the lock position shown in  FIG. 5 , the lever cannot pivot in the direction of arrow A′ shown in  FIG. 3  because the hook-type latch  23  is locked with the sliding pawl  43  of the release member  42 . When the release member  42  is depressed in the direction of arrow ‘B’ then the hook-type latch  23  is released from the sliding pawl  43  and the lever may be pivoted from the snare-on position ( FIG. 2 ) to the snare-off position ( FIG. 3 ). 
   The attached drawings show the preferred assembly for providing a positive locking mechanism. It is of course envisioned that the hook-type latch and pawl assembly shown in the drawings may be replaced by other mechanical locking system that prevent the snare tension from being accidentally or improperly disengaged or loosened during use by a performer. Likewise, it will be understood by those of skill in the art that other changes in form and detail may be made to the preferred embodiments described herein without departing from the spirit and scope of this invention. For example, the positive locking system of this invention could positively lock the tension of the snares separate and apart from the lever  40 . In other words, the locking system may be disposed on at a different location on the strainer apart from the lever  40 ; for example, the locking system could positively lock the piston  30  to the main body portion.