Abstract:
A percussive device for a stringed instrument includes a support structure, an attachment component that attaches the support structure to the stringed instrument, one or more hammers attached to arms rotatably coupled to the support structure and one or more actuators rotatably coupled to the support structure. User activation of the one of the actuators causes a corresponding one of the hammers to make contact with a string of the stringed instrument. A rotational force device applies a rotational force to at least one of the hammer arms or actuators. The rotational force device includes a torsion or helical compression spring. The applied rotational force causes the hammer to be positioned not in contact with the string of the stringed instrument. The applied rotational force is overcome when an applicable force has been applied to the corresponding actuator by a user, thereby causing the at least one hammer to be positioned in contact with the corresponding string of the stringed instrument.

Description:
PRIORITY 
     This application claims the benefit of U.S. patent application Ser. No. 13/044,771 filed on Mar. 10, 2011 and further claims the benefit of U.S. Provisional Patent Application No. 61/768,321 filed on Feb. 22, 2013, the subject matter of each is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Many mechanical means have been provided in the past for use with guitars and similarly stringed instruments, but these means have been generally directed to simplifying the plucking of the strings by replacing manual plucking with mechanical plucking means. Examples of such means are those disclosed and described in U.S. Pat. No. 921,565 (Scarlett); U.S. Pat. No. 2,429,138 (Ruf); and U.S. Pat. No. 3,292,975 (Koniecki). Means have also been provided for changing the pitch of a string as it is plucked or strummed by lengthening or shortening the string, such as is disclosed and described in U.S. Pat. No. 2,574,881 to McBride. 
     No known means have been heretofore provided whereby the notes of a stringed instrument can be mechanically actuated like the strings in a piano. 
     The present invention provides a percussive device for a stringed instrument. The percussive device includes a support structure, an attachment component that attaches the support structure to the stringed instrument, one or more hammers attached to arms rotatably coupled to the support structure and one or more actuators rotatably coupled to the support structure. User activation of the one of the actuators causes a corresponding one of the hammers to make contact with a string of the stringed instrument. 
     In one aspect of the invention, a rotational force device applies a rotational force to at least one of the hammer arms or actuators. The rotational force device includes a torsion or helical compression spring. The applied rotational force causes the hammer to be positioned not in contact with the string of the stringed instrument. The applied rotational force is overcome when an applicable force has been applied to the corresponding actuator by a user, thereby causing the at least one hammer to be positioned in contact with the corresponding string of the stringed instrument. 
     In another aspect of the invention, the support structure includes two side sections that are located on either side of the strings of the stringed instrument when the device is attached thereto. The attachment component includes a strap received through one or more slots located in the support structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
         FIG. 1  is a perspective view of the present invention attached to a guitar; 
         FIG. 2  is a perspective view of a percussive device formed in accordance with an embodiment of the present invention; 
         FIGS. 3 and 4  are side views of the device of  FIG. 2  in different modes of operation; 
         FIG. 5  is a top view of the device shown in  FIG. 2 ; 
         FIG. 6  is a perspective of an attachment device for the percussive device; 
         FIGS. 7A , B illustrate different operational modes in accordance with an embodiment of the present invention; 
         FIG. 8  is an x-ray side view of a percussive device formed in accordance with an alternate embodiment of the present invention; 
         FIG. 9  is a top view of actuation members for the percussive device formed in accordance with an alternate embodiment of the present invention; 
         FIG. 10  is a perspective view of a subassembly with cams according to an embodiment of the present invention; 
         FIG. 11  is an exploded, perspective of the subassembly of  FIG. 10 ; 
         FIG. 12  is an exploded, perspective view of a crossbeam and cams according to an embodiment of the present invention; 
         FIG. 13  is a side elevational view of a side member for the percussive device according to an embodiment of the present invention; 
         FIG. 14  is an exploded, perspective view of a side member having adjustable feet according to an embodiment of the present invention; 
         FIG. 15  is a side elevational view of the side member of  FIG. 14 ; 
         FIG. 16  is a close-up, cross-sectional view of an adjustable foot coupled to the side member of  FIG. 14  according to an embodiment of the present invention; 
         FIG. 17  is a side elevational view of a hammer head according to an embodiment of the present invention; and 
         FIG. 18  is an exploded, perspective view of the hammer head of  FIG. 17 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a perspective view of a guitar  22  and a percussive device  20  attached to the guitar  22  via a strap mechanism  26 . When a user activates the percussive device  20 , a percussive action is applied to the strings of the guitar  22 , thereby producing a tone caused by vibration of the percussed strings. 
       FIG. 2  illustrates a perspective view of the percussive device  20 . The percussive device  20  includes first and second sides  30 ,  32  that are connected via crossbeams  42 ,  44 , and  46 . Rotatably mounted to the first crossbeam  42  are a plurality of hammer arms  38 . Each of the hammer arms  38  includes a hammer head  34 . The number of hammer arms  38  corresponds to the number of strings (six for the guitar  22 ) that the device  20  is to be attached to. Rotatably mounted to the second crossbeam  44  are a plurality of actuators  40  that are equal in number to the hammer arms  38 . The third crossbeam  46  is located between the first and second crossbeams  42 ,  44 . The third crossbeam  46  and the second crossbeam  44  are located lower on the sides  30 ,  32  than is the first crossbeam  42 . The third crossbeam  46  is located below an interior end of the actuators  40 , when the percussive device  20  is in an at-rest position. The third crossbeam  46  keeps the actuators  40  from coming in contact with the strings  36  of the guitar  22 . 
     The percussive device  20  rests on the surface of the guitar  22  with legs of the side sections  30 ,  32  resting outside of the strings  36 . No other portion of the percussive device  20  comes in contact with the strings  36  except for when the hammer heads  34  are activated by the user. 
     Interior ends of the hammer arms  38  come in contact with top surfaces of the interior ends of the actuators  40 . Outboard ends of the actuators  40  include finger tabs  52  that extend beyond the frame of the sides  30 ,  32 . The finger tabs  52  include larger surface areas than the portions of the actuators  40  located between the sides  30 ,  32 , thereby allowing a user to make positive contact with the desired actuator. 
     Each of the sides  30 ,  32  includes a slot  50  for receiving the strap  26 , as shown in  FIG. 1 , for attaching the percussive device  20  to a musical instrument. The slots  50  are located between legs of the sides  30 ,  32  and below the crossbeams  42 ,  44 , and  46 . 
     The percussive device  20  shown in  FIG. 2  is in a relaxed position. This relaxed position is maintained by torsion springs (not shown) located where the actuators  40  make contact with the crossbeam  44  and where the hammer arms  38  make contact with the crossbeam  42 . The torsion springs associated with the actuators  40  cause the actuators  40  to rotate so that the interior ends of the actuators  40  are forced to rest on the crossbeam  46 . The torsion springs associated with the hammer arms  38  cause the hammer arms  38  to rotate so that an interior end of the hammer arms  38  is forced to come in contact with the respective interior ends of their associated actuators  40 . When a user depresses one of the tabs of the actuator  40 , the actuator  40  will rotate, thereby forcing the interior end of the actuator  40  in a vertical direction, thereby causing the respective hammer head  34  to rotate and, thus, make contact with the string that the hammer head  34  is above. Once the user has removed force from the tab  52 , the percussion device  20  returns to the relaxed position. 
       FIG. 3  shows a side view of the percussive device  20  in the relaxed position.  FIG. 4  shows a side view of the percussive device  20  at the moment that the hammer head  34  strikes the respective string  36 , as a result of activation of the associated actuator  40 . 
       FIG. 5  illustrates a top view of the percussive device  20  of  FIGS. 1 and 4 . 
       FIG. 6  illustrates a strap  54  that is received through the strap slots  50  of the sides  32 ,  30 . In one embodiment, the strap  54  is long enough to wrap around the instrument and attach to itself using various types of attachment mechanisms, such as Velcro or snaps. In another embodiment, the strap  54  is attached directly to the instrument using some form of attachment mechanism. Other types of mechanisms are used for attaching the percussive device to the instrument, for example, suction cups. In another embodiment, a base is more permanently mounted to the instrument. The base does not include the working components of the percussive device. The working components of the percussive device and the base include an attachment device for allowing the working components to be quickly attached to the base. In another embodiment, a percussive device is built partially into the interior of the body of the guitar. 
       FIG. 7A  illustrates a percussive device  70  in a first at rest position and  FIG. 7B  illustrates a percussive device  70  in a second at rest position. The difference in the at rest positions is the height of the hammer heads  34  above the strings  36 . The height of the hammer heads  34  is controlled by the position of a crossbeam  66 . The crossbeam  66  is supported in grooves  64  in the side sections. A securing device (not shown), such as a pin or geared dial, secures the crossbeam  66  so the crossbeam  66  doesn&#39;t move within the groove  64  after it has been set. 
       FIG. 8  illustrates an x-ray side view of the operational portions of an exemplary percussive device  70 . The sides of the device  70  are not shown. The percussive device  70  includes additional crossbeams  72 ,  74  located below actuators  78  and hammer arms  76  that rotate about crossbeams  80  and  84 , respectively. These additional crossbeams  72 ,  74  have springs  82 ,  86  fixedly attached to a top surface of the crossbeams  72 ,  74 . There is one spring  82 ,  86  located below each of the actuators  78  and the hammer arms  76 . The springs  82 ,  86  are positioned such that the percussive device  70  will remain in the at-rest position, such as that shown in  FIG. 3 , when not being activated by a user. In other words, the force the springs  82 ,  86  apply to the actuators  78  and the hammer arms  76  is comparable to the force applied by the torsion springs in the embodiment shown in  FIGS. 2-5 . 
     As shown in  FIG. 9 , a percussive device  90  includes actuators  92  that include outboard ends (tabs)  102  that fan out toward one side  30  of the percussive device  90 . In this embodiment, the tabs  102  include a first end that is attached to the actuator or becomes the actuator. The tabs  102  fan out toward one of the sides  30  of the percussive device  90 . This allows a user to activate the percussive device  90  from the side of the attached instrument instead of from the end of the instrument. 
       FIGS. 10 and 11  show a subassembly  200  having a plurality of keys  202  fixed to fingers  204 , respectively, which in turn are rotationally coupled to a crossbeam  206 . A set of cams  208  includes an offset aperture  210  for receiving the crossbeam  206 . In the illustrated embodiment, the crossbeam  206  may replace one or more of the crossbeams  42 ,  44  and/or  46  ( FIGS. 1 and 2 ). As will be described in more detail below, the cams  208  allow a starting position of the hammer heads  34  ( FIGS. 2-4 ) to be adjusted. Such adjustments may advantageously permit a desired level of “attack” that may be achieved when the hammer heads  34  contact the percussive strings  36 . The term “attack” in music parlance refers to an extent a particular music note is achieved. In the present embodiment, the subassembly  200  enables a percussive device to be more or less sensitive to attack. An example of a conceptually similar system is a “soft pedal” system on a piano forte. In the piano, adjustment of the soft pedal system allows the hammer heads to be moved closer to or further from the piano strings. Less distance between the hammer heads and the strings generates less attack. 
       FIG. 12  is an exploded, perspective view of the crossbeam  206  and the cams  208 . The offset apertures  210  in the cams  208  receive the crossbeam  206 . The crossbeam  208  may be configured with flat surfaces  212  for interacting with set screws  214  and securing the crossbeam  206  to the cams  208 . Sets or kits of different sized cams  208  or same sized cams  208  having the offset aperture  210  moved slightly (e.g., less offset from the crossbeam or more offset therefrom) may be employed to achieve the desired level of attack. The side member  218  permits three different cam adjustments that advantageously allow the percussive device to be mounted to different types of stringed instruments. For example, the strings on acoustic guitars sit lower in relationship to its soundboard as compared to the strings on a bass guitar. The cams  208  enable a musician to adjust all of hammers as desired. As mentioned above, such adjustments may also be used to alter the level of attack. 
     Briefly referring to  FIG. 13 , the cams  208  may received in one or more of the openings  216   a ,  216   b  and/or  216   c  located in side member  218  depending on the level of attack desired by a musician. While only one side member  218  is illustrated in  FIG. 13  it is appreciated that the other side member (not shown) would be a mirror replica of the side member  218 . The side members  218  may be substituted for the first and second sides  30 ,  32  described above with reference to  FIG. 2 . 
       FIGS. 14 ,  15  and  16  show the side member  218  with adjustable feet  220 . The side member  218  includes a threaded openings  222  configured to receive threaded posts  224  extending from the feet  220 . The threaded openings  222  may take the form of internally threaded sleeves press fit into the side member  218  or a threaded opening tapped directly into the side member  218 . As best illustrated in  FIG. 16 , a bottom portion  226  of the foot  220  is fixed to the threaded post  224 . The bottom portion  226  may be made from any material such as, but not limited to, rubber or plastic materials that dampens or eliminate sound caused by movement of the percussive device relative to an instrument onto which it is installed (e.g., different types of stringed instruments such as, but not limited to guitars, ukuleles, standup bass, violin, and an electric bass). Such relative motion, without the dampening interface, may create undesirable acoustics that could diminish an overall sound quality or attach coming from playing the instrument. In addition, the feet  220  may be independently adjusted to account for installation differences on different types of instruments or to account for instruments that have contoured sound board surfaces. By way of example, a musician may desire to use the percussive device on several different guitars, so the feet  220  could be adjusted accordingly. 
       FIGS. 17 and 18  show a hammer head  300  according to another embodiment of the present invention. The hammer head  300  includes a body  302 , a clip  304  and a clip cover  306 . The body  302  include a slot  308  that permits the hammer head  300  to be adjusted relative to the hammer arms  38  ( FIG. 2 ) and thus also adjusted relative to the strings of the instrument being played or about to be played. The body  302  may be secured to the hammer arms  38  using a set screw (not shown). Preferably, the cams  208  ( FIG. 12 ) are adjusted first and then each hammer head  300  may be individually adjusted, for example to achieve more attack on just the E-string or E-note and/or to achieve a significantly different tonal quality. The clips  304  and cover  306  may be removed and replaced with other clips and/or covers made from different materials without necessitating a re-adjustment of the hammer head  300 . By way of example, one cover  206  may be made of felt to achieve a softer tone on one chord while an adjacent cover may be made of metal. 
     Rather than using the clip  304  and cover  304 , the hammer heads  300  may monolithic or unitary and removable. The musician may have a kit or set of hammer heads made from different materials that could be substituted independently to achieve an array of different sounds and effects. By way of example, the kit may include sets of hammer heads  300  made from different materials, having different densities, or combination of materials such as, but not limited to various metals, woods, felt, rubber, etc. 
     According to one or more of the above-described embodiments, the percussive device provides musicians an improved way to play a stringed instrument by percussively striking the strings rather than strumming or plucking the strings. The hammer heads  34  do not travel past the strings like in other devices such as the device described by Koniecki in U.S. Pat. No. 3,293,975. Also unlike Koniecki, the percussive device does not employ a dampener, aside from the mounting feet, because it is actually desirable to allow the strings to ring out after being struck. The percussive device thus advantageously allows the musician to strike the strings in a range of intensities and volume. 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, this invention may be scaled in size to be used with other stringed instruments, such as violin, cello, bass fiddle, etc. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.