Abstract:
A tuning knob and tuning knob system for a stringed instrument such as a guitar replaces the existing tuning knob. The present tuning knob is a cylindrical knob with exterior knurls and a central bore therethrough. At one end, the bore is adapted to be received over the tuning stem while the other end of the bore is configured to receive a crank. The crank provides additional leverage for instrument tuning.

Description:
FIELD OF THE INVENTION 
     The present invention relates to string instruments and, more particularly, to devices for tuning guitar strings. 
     BACKGROUND OF THE INVENTION 
     In guitars and other stringed musical instruments, such as sitars, banjos and the like, strings of various diameters are stretched across a bridge over a resonant box in order to produce sound. The strings terminate at one end to a hold down device on the resonant box, while the other end of the strings terminate on revolvable pegs disposed on a tuning head that is attached to a sleeve of the instrument. From time-to-time, the musician must replace a broken string or retune the particular string to the correct frequency. Each string is separately tuned to the desired frequency by adjusting its tension through rotation of a winding stem operatively coupled to the revolvable peg. Generally, the strings are tuned through loosening and tightening thereof. A stem knob coupled to the winding stem is gripped between the fore finger and thumb and hand cranking. 
     However, in some instances, it is not possible to accurately tune or tighten the strings by the fingers alone. It my not be possible to even rotate the knob. 
     Various prior art mechanisms have been devised to facilitate the tuning of such stringed instruments as guitars. These devices have ranged from ratchet and gear mechanisms to add on knobs. 
     However, these prior devices still require a sufficient amount of hand applied torque to adequately adjust the strings or are cumbersome to have and/or operate. 
     It is thus an object of the present invention to provide a device to facilitate the tuning of stringed instruments such as guitars. 
     It is a further object of the present invention to provide an after-market guitar string tuning assembly to replace the factory knobs to facilitate tuning. 
     SUMMARY OF THE INVENTION 
     The present invention is a guitar tuning knob adapted to receive a detachable crank for tuning the strings of the guitar. A manual or automatic screw driver may alternatively be used to turn the tuning knob. 
     The knob is further adapted to be mounted on an existing guitar string tuning knob stem. The knob is cylindrical shaped and includes knurls on the outside surface for gripping with the fingers. The knob has a central axial bore extending therethrough. The central axial bore defines a first diameter with a second diameter portion on one end that is sized to be received on the guitar string mounting stem. The central axial bore that further has a third diameter portion adapted to receive the end of the crank. The crank is an angled hexagonal-shaped metal member. 
     In accordance with another aspect of the present invention, the tuning knob and crank are presented as an after-market kit for attachment to the guitar. The kit includes the hardware necessary to make the attachment. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, more particular description of the invention, briefly summarized above, may be had by reference to the embodiment thereof which is illustrated in the appended drawings. 
     It is noted, however, that the appended drawings illustrate only a typical embodiment of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. Reference the appended drawings, wherein: 
     FIG. 1 is perspective view of a typical guitar having tuning knobs according to the present invention; 
     FIG. 2 as an enlarged perspective view of the guitar head having the present tuning knobs attached to the tuning stems with a tuning crank in place; 
     FIG. 3 is an exploded view of the assembly of the present tuning knob onto the mounting peg; 
     FIG. 4 is an enlarged cross-section view of the present tuning knob; 
     FIG. 5 is an enlarged left end view of the tuning knob as taken along line 5--5 of FIG. 4; 
     FIG. 6 is an enlarged right end view of the present tuning knob taken along line 6--6 of FIG. 4; and 
     FIG. 7 is an enlarged side view of the crank according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown a typical six string guitar generally designated 10. The guitar 10 includes a body 12 having a stem or handle 14 attached to a top portion of the body 12 with a tuning head 16 attached to the end of the stem 14 opposite the body 12. As is typical, the body 12 includes a resonant opening 18 and a string mounting platform 20 located near the bottom of the body 12 adjacent the resonant opening 18. The guitar 10 further includes a plurality of strings, generally designated 22 that are attached at one end to the string mounting assembly 20 and terminate at revolvable tuning pegs 24 disposed in the head 16. Each string 22 is connected to a separate tuning peg 24 and is wrapped therearound in known manner in the art. 
     Referring now to FIG. 2, the guitar head 16 is shown in enlarged detail. Each string 22 is shown attached to one of the revolvable or rotatable tuning peg 24, thus there are six (6) such tuning pegs. The tuning pegs 24 are each operatively connected via gearing or the like (not shown) on the underside of the head 16 to a rotatable transverse mounting stem 30. It should be understood that the tuning pegs 24 are coupled to the mounting stems 30 in a manner known in the art such that rotation of the tuning stem 30 causes rotation of the respectively coupled tuning peg 24. The direction of rotation of the tuning stem 30 corresponds to a direction of rotation of the tuning peg 24 to either tighten or loosen the associated string 22 along the neck 14 and body 12 of the guitar 10. 
     In accordance with the present invention a tuning knob 26 is shown attached to each tuning stem 30. For reference, a tuning crank 28 is shown disposed in one end of the tuning knob 26 in accordance with the present invention. The tuning knob 26 is cylindrical-shaped and includes a central axial bore 32 extending from one end of the knob to the other. Referring specifically to FIG. 4, the bore 32 defines a first diameter portion 34 extending from the right end 35 of the knob 26 an axial distance into the knob 26, and a second diameter portion 36 extending from the left end 37 of the knob 26 an axial distance into the knob. The first and second diameter portions 34, 36 extend into the knob 26 a given distance such that a third diameter portion 42 is defined. The first and second diameter portions 34 and 36 are thus in communication with each other via the third diameter portion 42, via annularly tapered ends 38 and 40. Thus, the bores 34, 36, and 42 constitute the central bore 32. The knob 26 further includes a bevel or chamfer 44 on the right peripheral end and a bevel or chamfer 46 on the left peripheral end thereof as viewed in FIG. 4. 
     As best seen in FIG. 6, the first diameter portion 34 is shaped to receive the oval stem portion 48 of to the central stem 30. Referring now to FIG. 3, the manner in which the knob 26 is attached to or assembled on the stem 30 is shown in an exploded view. Several washers 50, shown here as three washers, are sized to be received over the stem 48. More or less washers 50 may be used depending on the length of the stem portion 48. The knob 26 is placed onto the stem portion 48 with the bore 34 towards the stem 30. The annular taper 38 seats the stem portion 48 within the knob 26. A spring washer 52 is inserted in the second diameter portion 36 with a screw or bolt 54 placed therein. The screw 54 extends through the bore 32 to engage the threaded bore 49 in the stem portion 48. Upon tightening, the bolt head 55 engages and rests against the annular taper 40, thus tightening and attaching the knob 26 onto the stem 30. 
     In accordance with the present invention and referring to FIG. 7, a crank 28 is provided. The crank 28 includes a first length 56 having a hexagonal cross-section with a transverse second member 58 attached at one end that also has a hexagonal cross-section, and a third portion 60 transverse to the second portion 58 and connected to the end opposite the connection to the first portion 56. The third portion 60 likewise has a hexagonal cross-section. It can be seen from FIG. 5 that the second diameter portion 36 has a hexagonal cross-section 64 for receipt of the crank 28. While the knob 26 has knurls 62 on the outside surface thereof for frictional gripping of the knob to turn between the fingers, the knob includes the keyed bore for receiving the crank as best shown in FIG. 2. It should be apparent that other configurations of crank and associated bore may be utilized. 
     In operation, and referring to FIG. 2, the strings 22 of the guitar are each wound on a separate tuning peg 24. Thus, as the knob 26 is rotated, the peg 24 likewise rotates to loosen or tighten the strings. The crank 28 is insertable into the hexagonal bore 36 to provide leverage and ease of string tuning. Alternatively, the crank may be attached to a manual or automatic screwdriver for additional leverage. 
     While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.