Abstract:
A peg winder for use with a stringed instrument in which each string is held in tension by a peg that can be turned by a person holding the instrument to change the tension and thereby tune the string to a target frequency or facilitate peg-winding as is required to install new guitar strings and bring each string up to proper tension. The peg winder is integrated with an electronic tuner such that the tension in the string can be adjusted while the person observes indicia on the tuner indicative of the vibrational frequency of the string. Preferably, the tool also has a string cutter mounted at the back end of the body.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention is directed to a tool for adjusting the tension of strings in a stringed instrument, until the string vibrates at a target frequency.  
         [0002]     Many stringed instruments have a plurality of strings that are fixed to the instrument body at one end, while maintained in tension at the other end by an adjustable holding mechanism, such as a peg that can be manually rotated to increase or decrease the tension, and thus vibration frequency, of the string. Although most such pegs are capable of being adjustably rotated by grasping between the thumb and forefinger, the effort can be excessive and the direct manual adjusting may be slow. In order to install a new string onto the instrument, the tuning peg must be rotated quickly and repeatedly. For fine tuning a strung guitar, the musician can hold the guitar in the play position, with one hand positioned to pluck a selected string, and the other hand available to adjust the peg on the neck while the string vibrates. A tuning device is located within the vicinity of the instrument, for comparing the frequency of the vibrating string with a target frequency to which that string is be tuned. The musician plucks and adjust the string tension one or more times until the string vibrates at the target frequency. Conventionally, the tension adjustment and the frequency comparison have been performed sequentially, as distinct but related steps.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention not only physically integrates the peg winder and tuner into one tool, but preferably configures the tool such that the frequency comparison is simultaneously displayed while the peg winder is adjusting the string tension. This represents a significant convenience to musicians who perform the task of changing guitar strings, especially home guitar re-stringing routines. Also, this can minimize the delays and distractions associated with keeping an instrument in tune during a performance. As a further improvement to minimize the time involved in replacing a string, a string cutter is preferably integrated with the peg winder and tuner.  
         [0004]     Thus, the present invention is more particularly directed to a tool for a stringed instrument in which each string is held in tension by a peg having a head with standard external profile, whereby the tool facilitates turning of the pegs rapidly to take up slack, as is the case when new strings are installed. The string can be readily brought to target frequency (musical pitch) by a person holding the instrument to change the tension. The device is integrated with an electronic tuner such that the tension in the string can be adjusted while the person observes indicia on the tuner indicative of the vibrational frequency of the string.  
         [0005]     In one particular embodiment the tool comprises a elongated body having front and back ends and an exterior surface shaped for grasping in one hand. A peg winder projects from the front end of the body and includes an end-effector formed with an internal profile that is complementary to the peg profile. A transducer is at one location at the surface of the body, for receiving energy from a vibrating string to be tuned. A tuning indicator is visible at another location at the surface of the body, for generating a signal commensurate with the difference between the vibration frequency of the plucked string and the target frequency.  
         [0006]     Preferably, the tool also has a string cutter mounted at the back end of the body. In one embodiment, the string cutter comprises a first cutting arm with first cutting edge rigidly extending from the back end of the body, and a second cutting arm pivotally mounted at the back of the body and extending along the top exterior surface of the body, whereby the second arm can be selectively pivoted between open and closed positions away from and adjacent to the body. The second cutting arm has a second cutting edge confronting the first cutting edge such when the second arm is in one position a string can be placed between the cutting edges and when the arm is in the other position the cutting edges sever the string. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is perspective view of a tool for a stringed instrument in which a tuner is integrated with a peg winder and string cutter, according to one embodiment of the invention;  
         [0008]      FIGS. 2-5  are left side, bottom, right side, and top views, respectively, of the tool of  FIG. 1 ;  
         [0009]      FIG. 6  is a detailed perspective view of the peg winder of the tool of  FIGS. 1-5 , and as would appear on a similar tool without the string cutter feature;  
         [0010]      FIG. 7  is an exploded view of the tool of  FIGS. 1-5 ;  
         [0011]      FIG. 8  is a block diagram of the electrical circuit of an electronic tuner usable with the present invention for tuning a musical instrument; and  
         [0012]      FIG. 9  is a front view of a preferred form of a display interface usable with the present invention. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0013]      FIGS. 1-5  show a tool  10  for a stringed instrument in which each string is held in tension by a peg having a head with standard external profile that can be tuned by a person holding the instrument to change the tension and thereby tune the string. An elongated body  12  has front  14  and back  16  ends shaped for grasping in one hand while the instrument is held for tuning. A peg winder  18  projects from the front end of the body and includes an end-effector  20  formed with an internal profile that is complementary to the standard profile of the peg. A tuning system is situated in the body, including a transducer  22  for receiving energy from a plucked string to be tuned, a frequency analyzer coupled to the transducer for comparing the fundamental frequency of vibration of the plucked string with a target frequency, and a display  24  coupled to the frequency analyzer and visible on the body. The display  24  includes an indicator  46  commensurate with the difference between the analyzed fundamental frequency of the plucked string and the target frequency, which is selectable via switch  44  or the like. The peg winder  18  includes a stem  26  rigidly projecting from the front end of the body along a stem axis  28  that passes longitudinally through the body and an arm  30  extending transversely to the stem axis and rotatably mounted on the stem. The end effector  20  rigidly projects from the arm.  
         [0014]     The body  12  is preferably formed by spaced apart, left  32  and right  34  side surfaces, opposed top  36  and bottom  38  surfaces that connect the side surfaces, and front  40  and back surfaces  42  that together with the side and top surfaces form a closed handle  12  sized and shaped to fit in a person&#39;s closed hand with the stem axis  28  oriented in substantially in the same direction as the lifeline of the closed hand. The side surfaces  32 ,  34  of the body increase in area from the back to the front ends and the tuning indicator  24  is adjacent the front end. The top  36  and bottom  38  surfaces of the body are curved in the same direction, but with different radii of curvature.  
         [0015]     Optionally, the tool has a string cutter  48  mounted at the back end. The string cutter  48  comprises a first cutting arm  50  with first cutting edge  52  rigidly extending from the back end of the body, and a second cutting arm  54  pivotally mounted  56  at the back of the body and extending along the top  36  exterior surface of the body. The second arm  54  of the string cutter is curved at substantially the same radius of curvature as the body top surface. The second arm  54  can be selectively pivoted between open and closed positions away from and adjacent to the body, respectively. A second cutting edge  58  confronts the first cutting edge  52  such that when the second arm is in one position a string can be placed between the cutting edges and when the arm  54  is in the other position the cutting edges sever the placed string. A shield  60  with through hole  62  can be secured to the body such that the hole  62  permits passage of the string between the cutting edges to be severed when the second arm is moved to the cutting position.  
         [0016]      FIG. 6  shows further details of the preferred form of the end effector  20  with a portion  44 ,  46  of the associated tuner at the front portion of the body. It should be appreciated that in this embodiment, no string cutter is present, but the remainder of the body and tuner are substantially identical to the corresponding structure described with respect to  FIGS. 1-5 . The end effector  20  is rotatably mounted to the front of the body, and has a recess  64  defined by wall structure forming, for example, an asymmetric cross. This results in a first socket defined by a pair of notches  66  that can conform to an oval peg head whereas a second socket is defined by the other pair of notches  68  that can conform to a rectangular peg head. A portion  70  of a stringed instrument is shown adjacent the end effector  20 , whereby the peg head  72  can be closely received in notch  68 , for rotating the peg stem  74 , which in turn increases or decreases the wrapping of the string. The wrapping affects the tension and thus vibration frequency in the voice portion  76  of the string, whereas the free end  78  of the string can remain untrimmed. In the preferred embodiment of the invention as shown in  FIG. 1 , after tuning has been achieved, the tool is reversed and the free end  78  of the string can be trimmed.  
         [0017]      FIG. 7  is an exploded view of the tool shown in  FIGS. 1-5 . The body is primarily formed by two half-shells,  80 ,  82 . A tuner mounting plate  84  is situated between the shells, adjacent the shell  80  having the surface where the tuning display  24  is located. The transducer  22  and the tuning display  24  are situated between the tuner mounting plate  84  and the shell  80 , and a battery  86  for the tuning system is situated between the tuner mounting plate  84  and the other shell  82 . The tuner mounting plate  84  is substantially flat with a peripheral edge  88 . A core plate  90  is situated between the tuner mounting plate  84  and the other shell  82 , the core plate having front and back ends,  92 ,  94  a first side facing  96  the tuning plate, and a second side  98  facing the other shell  82 . The first side has a web  100  at the front end and a peripheral edge  102  that support the peripheral edge  88  of the tuner plate. The first, rigid or fixed string cutter arm  50  is integral with and extends from the core plate  90  through the back end of the body.  
         [0018]     A positive battery contact  110  is located at the periphery of the plate  84 , and the negative contact  112  is located adjacently, at the center of the plate. These contact the battery  86  on the side of the plate facing shell portion  82 . A battery cover  104  secures the battery in place against the contacts on this side of the plate  84 .  
         [0019]     The tuner mounting plate  84  is a printed circuit board (PCB)  106 . On the side facing shell portion  80 , the transducer  22  includes a microphone carried by the PCB, and the display  24  includes a plurality of LED&#39;s  116  carried by the PCB. A miniature, tactile power on/off switch  114  is mounted on the PCB, and a power select button  122  is accessible at the surface of the body for operative association with the power on/off switch. The display includes an annular lens  120  surrounding the power button  122  at the body surface with indicia that are selectively illuminated by the LED&#39;s.  
         [0020]     A miniature tactile switch  108  is located on the side of the plate  84  facing shell portion  82 , and is aligned with core  90  and includes a recess for receiving a switch ( 44  as shown as  FIG. 5 ) for selecting the target frequency, as will be described in greater detailed below.  
         [0021]     The display  24  preferably includes not only the lens  120 , but a light pipe  118 , having a plurality of light-transmitting passage ways corresponding respectively to the plurality of LED&#39;s  116 .  
         [0022]     In the illustrated embodiment, which includes a string cutter, the moveable string cutter arm  54  is part of an assembly  128  including a cutter handle  128  with a flange portion that is accessible at the exterior of the body for operating the arm, and a support portion which is rigidly connected to the arm  54 , in which nest in a corresponding contour formed in the body portion when the body is assembled. Each of the cutter arm  54 ,  54  has a central aperture  124  through which a pivot pin  130  passes and is secured therein via knot  132 . Thus, the core  90  can be considered as the frame work for a core arm assembly  126  that remain fixed with respect to the body, whereas the arm  54  is pivots in relation thereto, about pin  130 .  
         [0023]      FIG. 7  also shows the peg winder portion  18  whereby the stem portion  26  includes a central aperture  134  though which a mounting screw  136  passes, to secure the peg winder  18  to the front end of the body. The stem  26  has a groove or channel which allows the user to ‘stretch’ the string, if desired, thus helping the target frequency to settle more quickly, without repeated re-tunings.  
         [0024]      FIGS. 8 and 9  show the preferred implementation of the tuner aspect of the invention, as a supplement to  FIG. 7 .  
         [0025]      FIG. 8  is a block diagram of a circuit  200  of suitable electronics, which controls the illumination of the display interface  24 ,  116  connected thereto. When the instrument to be tuned is an acoustic musical instrument  202 , a microphone  204 , preferably internal to the electronic tuner, receives acoustic waves  206  from the acoustic instrument. The microphone acts as the transducer  22  of  FIG. 1 , converting the acoustic waves  206  to an output electrical analog sine wave signal  208  having a frequency which corresponds to that of the musical note played on the instrument.  
         [0026]     The circuit  200  of the electronic tuner further includes an audio amplifier  216  which receives the electric signal  208  and amplifies it, thereby generating amplified analog sine wave signal  208   a . The amplified analog sine wave signal  208   a  is provided to a voltage comparator  218 , which clips the amplified analog sine wave signal  208   a  and converts it to a digital logic electrical signal  220 , so that it is compatible for operation with the remaining digital components of the tuner circuit. A microcontroller or microprocessor  222  is coupled to the voltage comparator  218  and receives the digitized electrical signal  220 . The microcontroller  222  includes, either internally or externally, a storage memory  224 , which stores the frequencies corresponding to twelve musical notes, e.g., the fundamental frequencies for notes A, A#/(Bb), B, C, C#/(Db), D, D#/(Eb), E, F, F#/(Gb), G and G#/(Ab). Microcontroller  222  also includes, either internally or externally, a frequency comparator  226 . The microcontroller  222  determines by means of the frequency comparator  226  which of the fundamental frequencies corresponding to the musical notes stored in the storage memory  224  the electrical signal  220  most closely equals.  
         [0027]     The display interface of the present invention, in the form of an optical display, preferably includes a circular array of circumferentially spaced apart bi-color light emitting diodes (LEDs)  116 , connected to and driven by the microcontroller  222 . Each of the LEDs  116  represents one of the fundamental frequencies of the musical notes mentioned previously. The tuner circuit  200  also includes a display mode selector switch  228  and a reference pitch selector switch  122 , each of which is operatively coupled to the microcontroller  222 .  
         [0028]      FIG. 9  illustrates a preferred form of the display interface  24  of the present invention, having a note dial  120 , illuminated by the circular array of bi-color LEDs  116  described previously. The note dial  120  displays characters  230  representing twelve musical notes: A, A#/(Bb), B, C, C#/(Db), D, D#/(Eb), E, F, F#/(Gb), G and G#/(Ab). Preferably, the notes are circularly arranged in a manner like the dial of a clock so that note A is at the 12 o&#39;clock position, note C is at the 3 o&#39;clock position, note Eb is at the 6 o&#39;clock position, and note F# is at the 9 o&#39;clock position. The display mode selector switch  122 , which also functions as a power on/off switch, is preferably disposed at the center of the note dial. Of course, it is envisioned that a separate power switch may be included, if desired. Preferably viewable at the outer circumference of the note dial  120  is an array of transparent, illuminatable segments  232  that are circularly arranged radially outwardly of the characters  230 . These segments  232  are viewable portions of a light pipe  118  situated behind the note dial  218 . Preferably, the LEDs  116  are disposed behind the musical note characters  230  and the transparent segments  232 . Thus, each of the musical note characters  230  and the transparent segments  232  is illuminated simultaneously by a respective LED situated behind them.  
         [0029]     The cylindrically-shaped light pipe  118 , has radially extending slits  234  formed in its front surface and rear surface, to define twelve individually illuminatable segments  232 , situated adjacent to the circular array of LEDs  116 . The rear surface of the light pipe has further formed therein recesses or openings, one opening situated within each segment  232 , to receive the LEDs  116 . Accordingly, when any given LED  116  illuminates, the corresponding segment  232  of the light pipe is illuminated thereby.  
         [0030]     The disc-shaped note dial  120  is situated concentrically over the front surface of the light pipe  118 . The note dial has a smaller diameter than that of the light pipe so that only the outer portions of segments  232  not blocked by the note dial are viewable to the user. As mentioned previously, the note dial  120  has imprinted on the surface thereof indicia in the form of the twelve musical notes  230  of one octave. The note dial is preferably opaque, except for the note indicia  230 . Each note indicia is situated in alignment with one corresponding segment  232  of the light pipe  118  so that the note indicia  230  appears as being backlit and readable by a user when a corresponding LED  116  illuminates.  
         [0031]     Each of the light pipe  118  and the note dial  120  has formed centrally through the thickness thereof an opening, respectively, to receive the pushbutton cap of switch  122 . The pushbutton cap  122  includes a radially extending flange  234  so that it is held captive within the tool body by the light pipe  118  and note dial  120 , but moveable within the openings so that it may be pressed by a user to activate switch  114 .  
         [0032]     The note dial  120  is aligned with an opening  236  formed in the front half of the housing tool body. The diameter of the opening  236  is slightly smaller than that of the note dial so that the note dial is held captive within the interior of the body.  
         [0033]     In the sweep mode of operation, the LED  116 ′ corresponding to the note played lights up in one color, for example, green, designated by the letter G. An LED  116 ″ in a different color, for example, red, will appear counter-clockwise of the green LED  116 ′ if the note played is flat, and clockwise of the green LED  116 ′ at  116 ′″ if the note is sharp. When only the green LED  116 ′ is lit, the instrument is in tune with respect to that note played.  
         [0034]     It should be noted that the microprocessor  222  can pulse width modulate the illumination of a plurality of adjacent red LEDs  116 ″ or  116 ′″ to show a smooth movement of the pitch of the played note as the musical instrument is being tuned. Thus, only one green LED  116 ′, signifying the reference note G, is illuminated at any one time, but two adjacent red LEDs signify how sharp or flat the played note is, may be pulse width modulated to at least partially illuminate together to provide a smoothly varying display.  
         [0035]     Alternatively or additionally, when the user presses the mode pushbutton switch  122  a second time, the electronic tuner enters the strobe mode of operation. The LEDs  116  illuminate sequentially in red around the note dial  120  a few times to indicate to the user that the tuner is in the strobe mode. In the strobe mode of operation, the LED  116 ′ corresponding to the note played lights up in one color, for example, green. The other LEDs sequentially illuminate in a different color, for example, red, in either a counter-clockwise or clockwise direction about the note dial  120 . Both the direction and speed of the illuminating red LEDs provide information to the user as to how out of tune the instrument is. When the red LEDs illuminate sequentially in a counter-clockwise direction, this indicates that the played note is flat compared to the reference note G. When the red LEDs  116  sequentially illuminate in a clockwise direction, this indicates to the user that the played note is sharp compared to the reference note G. The angular velocity or speed at which the red LEDs sequentially illuminate is proportional to how sharp or flat the played note is. As the instrument is tuned so that the frequency of the played note approaches the frequency of the reference note, the angular velocity or speed at which the red LEDs sequentially illuminate decreases and then stops, indicating that the note is in tune.  
         [0036]     Returning again to  FIG. 8 , the circuit  200  includes a reference pitch selector switch  44 . The electronic tuner operates on a standard pitch of 440 Hz for the note A. However, it is often desired to tune a musical instrument to a slightly different reference frequency from that of the standard pitch of 440 Hz. Accordingly, the electronic tuner provides the user with the ability to select a different reference frequency, preferably between 435 Hz and 445 Hz for note A. The selected frequency is indicated on display  46  at the front of the body on the side opposite display  24 .