Variations of adjustable guitar nut

Abstract

Variations of an adjustable guitar nut design. The guitar nut can be symmetric or asymmetric. The guitar nut can be fully adjustable by incorporation of a rack and pinion adjustment mechanism or a screw drive adjustment mechanism. Other variations are fully adjustable designs for internally compensated nuts, shelf nuts, zerofret and multi-scale nuts, and locking tremolo nuts. The adjustment can be locking or solid with adjustable saddle pieces. The guitar nut can be modified for uni and multi scale instruments, with a screw drive top partition nut, a screw drive zero fret nut, or a combination of the same. The guitar nut may also have an adjustable fingerboard mounted rack and pinion drive zerofret and integrated nut. Lastly, the guitar nut may be one of a variety of friction fit adjustable saddle shelf nut designs.

Description

[0001] VARIATIONS OF ADJUSTABLE GUITAR NUT

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of priority to United States Provisional Application Nos. 63 / 509,982, filed on June 23, 2023, 63 / 511,376, filed on Jun 30, 2023, 63 / 513,715, filed on July 14, 2023 and 63 / 622,666 filed on January 19, 2024, the contents of which are hereby incorporated by reference in their entireties.

[0004] BACKGROUND

[0005] 1. Field of the Invention

[0006] The invention relates to guitars, in particular guitar nuts, for improvement of guitar pitch stability and variations thereto.

[0007] 2. Description of the Background Art

[0008] Standard guitars have a body, elongated neck, finger board, bridge, nut, and a series of frets positioned along the neck. The frets are ridges of material such as metal or wood which extend outwardly and generally perpendicularly across the finger board of the guitar. The frets are typically positioned according to a mathematical formula called the “Rule of 18” which is used to determine the position of the frets. The frets allow for other notes and chords to be played when the guitar player's fingers press down on the desired guitar strings at the selected frets locations between the bridge and the nut.

[0009] Known guitar nuts consist of a single nut, or solid piece of material, that may be permanently secured to the neck of the guitar to be maintained in a fixed position thereon to adequately support the strings in an elevated position to allow for playing of the guitar. Examples of such may be found in at least U.S. Pat. Nos. 4,295,404, or US 6,433,264. Experts concur that a guitar is an imperfect instrument, and that it is impossible for it to play perfectly in tune at all times. This is due to a serious design flaw inherent in all guitars which cause them to play out of tune, and lack ability to adjust the instrument intonations at the guitar nut.

[0010] Guitars and other fretted instruments are precision assemblies. In order to play accurate tones in half semitone increments all across the fretboard, the strings and physical location of the strings anchor points need to be individually calibrated to the correct values; a process commonly known as “intonating” the strings.

[0011] Intonations is tension and strong property specific. Each time the size, type, or even brand of strings is used, or a different tuning style implemented, you need to intonate and adjust the instrument to match the new tension and string variables.

[0012] Intonation shortens or lengthens the string lengths so that it maps to the fretboard and accurately plays notes. Adjustments at the bridge of the guitar map the strings from the 7thfret and higher. Adjustments at the nut map the strings from the 1stthrough 6thfrets.

[0013] Almost all guitars, except acoustic guitars, feature an adjustable bridge; none of them have an adjustable nut.

[0014] A guitar nut serves three main purposes: 1) it anchors and positions the strings in the correct position; 2) it channels string vibration energy into the instrument; and, 3) it anchors the string in a specific X, Y, and Z coordinate. The location of this coordinate governs intonation. All guitar nuts of statis design are typically made from a single material or material composite, and it is not possible to adjust intonation as the anchor point is fixed.

[0015] There are two main types of guitar nuts: 1) straight edge nuts, where the front edge of the nut also functions as the anchor point which fixes the X, Y, and Z position of the string’s breakpoint; and 2) compensated nuts, which feature offset anchor points in the Y axis responsible for string intonation from the first through sixth frets. There are two types of compensated nuts: 1) Internal compensated nuts, such as Ernie Balls patented nut; and 2) Shelf nuts, such as Earvana and Minehara from Japan.

[0016] Instruments with standard straight edge nuts never intonate properly. Instruments equipped with Ernie Ball’s internal compensated nut or Earvana’ s Compensated shelf nut intonate properly only if the correct string gauge / properties and tuning are used.

[0017] Since players are constantly using different strings and tunings, they need an instrument where both anchor points can be adjusted.

[0018] Therefore, there exists a need to create a mechanism to allow for intonation adjustment in order to accommodate the sheer number of different types of string and string materials. By incorporating adjustment mechanisms into the nut adjustment saddles, it is possible to accurately adjust an intonate the instrument under tension with a simple turn of the pinion gear.

[0019] SUMMARY

[0020] It has been devised a number of fully adjustable guitar nuts which incorporate both rack and pinion and screw type drive adjustment mechanisms. One aspect of the present disclosure is an adjustable guitar nut which features a rack and pinion mechanism. In some embodiments, the adjustment of the adjustable guitar nut can instead be effectuated with a screw drive adjustment mechanism.

[0021] Another aspect of the disclosure is an adjustable guitar nut body milled from a single solid material. The material is typically a plastic or plastic derivative.

[0022] Another aspect of the disclosure is a guitar nut back plate which also functions as a mounting plate for said guitar nut.

[0023] Also disclosed is an encased adjustable guitar nut with a rack and pinion adjustment mechanism having internal adjustment values. The encased adjustable guitar nut may have screw drive mechanisms with internal adjustment values, or rack and pinion adjustment mechanisms. The string saddles may or may not extend over the fingerboard.

[0024] Another aspect of the present disclosure is an encased adjustable guitar zerofret or multiscale nut, featuring a rack and pinion adjustment where the string saddles extend over the fingerboard.

[0025] In an additional aspect of the present disclosure is an adjustable rack and pinion nut for locking tremolo guitars, having string saddles that extend over the fingerboard.

[0026] Additionally disclosed is an acoustic guitar bridge with a rack and pinion drive mechanism. The acoustic guitar may be equipped with an acoustic bridge and any version of the adjustable nuts disclosed herein. Alternatively, an electric guitar may be equipped with any of the adjustable nuts disclosed herein.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS While various embodiments are illustrated in the drawings, the embodiments shown should not be construed to limit the claims. Various modifications and changes may be made without departing from the scope of the invention.

[0028] FIG. 1 illustrates an anterior perspective view of the rack and pinion adjustable nut.

[0029] FIG. 2 illustrates an anterior perspective view of the screw drive adjustable nut, note screw axles protruding from the nut body.

[0030] FIG. 3 illustrates a posterior perspective view of the rack and pinion adjustable nut

[0031] FIG. 4 illustrates a posterior view of the screw drive mechanism adjustable nut, note screw adjustment heads countersunk and imbedded into the nut body.

[0032] FIG. 5 illustrates an exploded view of both nuts.

[0033] FIG. 6 illustrates the back cover plate of both nut designs. It is also used to mount the nut to the instrument.

[0034] FIG. 7 illustrates the posterior perspective view of the internal design of the rack and pinion nut version.

[0035] FIG. 8 illustrates the posterior perspective view of the internal design of the screw drive nut version.

[0036] FIG. 9 illustrates the string saddles which press fit into the adjustment mechanism.

[0037] FIG. 10 illustrates the hardened steel rack insert plate containing the rack geometry for each string slot, FIG. 11 illustrates the combination involute pinion drive / adjustment post / string saddle mounting post.

[0038] FIG. 12 illustrates the screw drive string support posts.

[0039] FIG. 13 illustrates the screw drive mechanism, held in place with a C-clip.

[0040] FIG. 14 illustrates the milled, molded, or cast nut body of both nuts.

[0041] FIG. 15 illustrates the press fit channel which houses the rack geometry for the rack and pinion nut.

[0042] FIG. 16 illustrates the steel rack component.

[0043] FIG. 17 illustrates an assembled pinion drive unit.

[0044] FIG. 18 illustrates a string mounting post.

[0045] FIG. 19 illustrates the integrated involute pion gear and adjustment screw geometry.

[0046] FIG. 20 illustrates the screw which holds the pinion drive in place.

[0047] FIG. 21 illustrates a locking nut version of the pinion drive nut.

[0048] FIG. 22 illustrates a Zero fret guitar nut with string saddles extending over the fingerboard.

[0049] FIG. 23 illustrates a standard shelf nut where the string partition extends over the fingerboard. FIG. 24 illustrates a detailed view of a shelf nut, note string slots to guide strings and Allen key adjustment.

[0050] FIG. 25 illustrates an exploded view of a shelf nut, the top partition held in place with screws.

[0051] FIG. 26 illustrates the mechanics of the nut, pinion gear drives and rack guided string partitions.

[0052] FIG. 27 illustrates the base part of the nut, note the pocket geometry to fix the pinion gear in place.

[0053] FIG. 28 illustrates the zero-fret nut perspective view

[0054] FIG. 29 illustrates the top partition of the nut, note the string guide slots.

[0055] FIG. 30 illustrates the mechanics of the nut, note in this embodiment the screws mount from the side rather than the top.

[0056] FIG. 31 illustrates a detailed view multiscale nut, where the nut is mounted at an angle.

[0057] FIG. 32 illustrates the internal details of the nut.

[0058] FIG. 33 illustrates the base part of the nut with geometry for pinion gear.

[0059] FIG. 34 illustrates a locking tremolo nut assembly.

[0060] FIG. 35 illustrates an exploded view of the nut.

[0061] FIG. 36 illustrates an assembled base part of locking nut with the adjustment screws. FIG. 37 illustrates the interior of the part, the pinion gear retention geometry.

[0062] FIG. 38 illustrates the pinion gears.

[0063] FIG. 39 illustrates individual string saddle posts which extend over the fingerboard when adjusted.

[0064] FIG. 40 illustrates the top of the nut which is held in place with screws.

[0065] FIG. 41 illustrates the extended string saddle partitions of the screw drive shelf nut.

[0066] FIG. 42 illustrates the nut body of the screw drive shelf nut.

[0067] FIG. 43 illustrates the placement of the drive screws of the unit; they are held in place with C-clips.

[0068] FIG. 44 illustrates an exploded view of the encased adjustable shelf nut.

[0069] FIG. 45 illustrates the screws.

[0070] FIG. 46 illustrates the nut base part of the screw drive shelf nut note pockets for screw drive mechanics which exactly encase the mechanism to minimize vibrations.

[0071] FIG. 47 illustrates the string saddle partitions.

[0072] FIG. 48 illustrates the top of the nut, which has integrated sting slots, and is hollowed out in the middle to minimize excessive string contact with the nut.

[0073] FIG. 49 illustrates the adjustable acoustic guitar bridge complete assembly as it is mounted on the instrument. FIG. 50 illustrates the adjustable acoustic guitar bridge internal assembly which is mounted inside the wooden guitar bridge body.

[0074] FIG. 51 illustrates the acoustic guitar bridge assembly in exploded view, individual string saddle partitions which press fit onto the rack drive string saddle posts.

[0075] FIG. 52 illustrates the bridge base unit which has pockets milled to house the rack and pinion mechanism driving the saddles.

[0076] FIG. 53 illustrates the cover plate of the acoustic guitar bridge assembly.

[0077] FIG. 54 illustrates a wooden block which encloses the bridge internal assembly inside the wooden guitar bridge body.

[0078] FIG. 55 illustrates detailed view of the rack and pinion mechanism, showing a pinion drive which is offset.

[0079] FIG. 56 illustrates the rack geometry on the outside of the rack drive part.

[0080] FIG. 57 illustrates anterior perspective view of the screw drive top partition movement adjustable nut.

[0081] FIG. 58 illustrates extra mounting covers to facilitate proper installation.

[0082] FIG. 59 illustrates posterior perspective view of the screw drive top partition movement adjustable nut note the radius of the mating of the top partition and the nut body, the radius matches the fingerboard FIG. 60 illustrates posterior view of the interior of the screw drive mechanism top partition movement adjustable nut, note cover and geometry of the string saddle drive partitions

[0083] FIG. 61 illustrates exploded view of the screw drive mechanism top partition movement adjustable nut

[0084] FIG. 62 illustrates the nut body and geometry to enhance vibrational transfer from the matching string saddle drive geometry in FIG. 61.

[0085] FIG. 63 illustrates a screw drive top partition movement nut for a multiscale instrument. Note the offset saddle partitions and that, unlike a uni-scale guitar nut, a multi-scale guitar nut is mounted on the instrument at an angle, and that movement of the partitions follows the y -axis or string direction.

[0086] FIG. 64 illustrates a screw drive zero-fret partition movement nut for a multi scale instrument. Note the top of the nut is stationary.

[0087] FIG. 65 illustrates a combination screw drive zero-fret and top partition movement nut for a multiscale instrument, here the zerofret and the top partition of the nut move in unison.

[0088] FIG. 66 illustrates the interior of a screw drive top partition movement nut.

[0089] FIG. 67 illustrates the interior of a screw drive zero-fret partition movement nut for a multiscale instrument.

[0090] FIG. 68 illustrates the interior of a screw drive combined zero-fret and top partition movement nut for a multiscale instrument. FIG. 69 illustrates the fingerboard mounted zero fret intonation partition unit.

[0091] FIG. 70 illustrates the fingerboard mounted zero fret intonation partition unit with integrated nut.

[0092] FIG. 71 illustrates interior detail of the nut, note the nested rack and pinion mechanism common to our nut and bridge saddle designs.

[0093] FIG. 72 illustrates an integrated nut embodiment of the fingerboard mounted zero fret nut.

[0094] FIG. 73 illustrates the top of nut case

[0095] FIG. 74 illustrates the interior pockets located in the nut base which house the rack and pinion drive unit. Note that this nut unit is made for a guitar with a radiused fretboard. In this case the pocket housing the rack and pinion mechanism mates with the pocket located on the bottom of the top of the nut case. The pocket formed by both the top body of the case, showing that it precisely matches the dimensions and apply pressure to the rack drive mechanism. In the case of a flat non radiused fingerboard then the pocket housing the rack drive mechanism is contained to the bottom base part, the flat bottom of the top of the nut case housing applying pressure to the rack drive and pinion gear parts.

[0096] FIG. 75 illustrates the geometry that holds the pinion gear in place.

[0097] FIG. 76 illustrates the bottom of the top part of the nut housing. Note the pockets on the underside of the part which mate with the pockets on the bottom base part enclosing the rack drive mechanism. FIG. 77 illustrates the bottom geometry of the pinion gear nut which affixes it in place in the nut base.

[0098] FIG. 78 illustrates a fingerboard mounted nut design for Fender Stratocaster and Telecaster guitars. The internal design is the same as the fingerboard mounted zero fret nut. The difference between the zero fret and the fender version is that the Fender features string partitions with slotted geometry to hold the strings in place in the X axis. The zero fret is simply a metal fret with no string slots.

[0099] FIG. 79 illustrates the adjustment screws for the fender pinion nut.

[0100] FIG. 80 illustrates the fender pinion nut mounted on a guitar.

[0101] FIG. 81 illustrates a fender screw drive nut.

[0102] FIG. 82 illustrates the screw drive partition block.

[0103] FIG. 83 illustrates replaceable string saddle partitions

[0104] FIG. 84 illustrates the mechanism pocket geometry in the bottom part of the nut case.

[0105] FIG. 85 illustrates the mechanism pocket geometry in the top part of the nut case.

[0106] FIG. 86 illustrates an anterior perspective view of an adjustable fingerboard terminus mounted nut.

[0107] FIG. 87 illustrates an extended length partition for inflexible high tension / strain strings.

[0108] FIG. 88 illustrates an anterior perspective view of an adjustable slot mounted nut. FIG. 89 illustrates anterior perspective view of an adjustable asymmetric slot mounted nut.

[0109] FIG. 90 illustrates exploded view of the three different designs, terminus mounted, symmetric slot mounted and asymmetric slot mounted nut designs. Take note of the differing curved radii on the different designs which are designed to sit flush with the fingerboard.

[0110] FIG. 91 illustrates the nut base part featuring male geometry which mates with female geometry on the underside of FIG. 93 string saddle parts.

[0111] FIG. 92 illustrates fastening screws which affix the saddle partitions to the base part.

[0112] FIG. 93 illustrates an anterior top perspective view of the string saddle partitions.

[0113] FIG. 94 illustrates a posterior bottom perspective view of the saddle partitions and the female slot geometry which mates with the male top geometry and helps guide the part via a clearance fit.

[0114] FIG. 95 illustrates an example of an alternative embodiment of a terminus mounted nut, featuring single male geometry on the string saddle parts and female geometry in the base part.

[0115] FIG. 96 illustrates a slot mounted friction fit nut installed on a guitar.

[0116] FIG. 97 illustrates the base piece of the nut installed on a guitar, note the radius of the top of the part matches and sits flush with the fingerboard. FIG. 98 illustrates a friction fit locking nut, note the recess on the front of the part, a design element which permits the saddle partitions to move in the negative Y axis and meet with the fingerboard.

[0117] FIG. 99 illustrates an exploded view of a friction fit locking nut base part.

[0118] FIG. 100 illustrates an exploded view of the individual string saddle partitions of the locking nut and their cam geometry which matches the geometry in the base part.

[0119] FIG. 101 illustrates the locking tabs which lock the strings in place.

[0120] FIG. 102 illustrates the grub screws which interact with the cam geometry on the string partitions and lock them in place.

[0121] FIG. 103 illustrates the screws used to fasten the locking tabs

[0122] FIG. 104 illustrates the geometry and clearance fit between the string saddles and the nut body.

[0123] FIG. 105 illustrates an additional view of the geometry and clearance fit between the string saddles and the nut body.

[0124] FIG. 106 illustrates the friction fit locking nut mounted on a guitar, notice the underside of the string saddle partitions match and sit on top of the guitar’s fingerboard.

[0125] FIG. 107 illustrates a fingerboard mounted nut design, designed to be installed flush with the fingerboard. Note the recessed cavities in the nut body which permit travel for the individual string saddle partitions. FIG. 108 illustrates an anterior perspective view of the string saddle partitions.

[0126] FIG. 109 illustrates an anterior perspective view of the nut case bottom piece.

[0127] FIG. 110 illustrates an anterior perspective view of the nut case top part.

[0128] FIG. I l l illustrates an anterior perspective view of the case screws.

[0129] FIG. 112 illustrates an anterior perspective view of the grub screws which lock the string partitions in place.

[0130] FIG. 113 illustrates the clearance fit interaction between the string saddle cam geometry and the geometry in the nut case. Note that the cam thickness of the individual string saddle piece differ and follow the radius of the part and fit the volume of the cavities formed in the nut base 2-part clamshell assembly.

[0131] FIG. 114 illustrates the cam geometry of the string saddle partitions which share a clearance fit in the cavity formed by the assembly of the nut case bottom part of Fig. 115 and the top part of Fig. 116. Note that the protruding geometry on the underside of the nut case top part. This geometry is designed to interact via a clearance fit with the top surface of the cam geometry of string saddle partitions.

[0132] FIG. 115 illustrates the assembly of the bottom part of the nut case.

[0133] FIG. 116 illustrates the assembly of the top part of the nut case.

[0134] FIG. 117 illustrates a grouping of terminus mounted mechanical adjustable nut family at the end of the fingerboard. FIG.l 18 illustrates a stamped metal version of the nut with U-shaped nut body profile and internally adjustable saddles.

[0135] FIG. 119 illustrates a molded encased nut body and internally adjustable saddles.

[0136] FIG. 120 illustrates a shelf nut version of the nut with saddle partitions that extend over the fretboard.

[0137] FIG. 121 illustrates rear views of a grouping terminus of mounted (end of fingerboard) mechanical adjustable nut family of FIGS. 118-120.

[0138] FIG. 122 illustrates an exploded view of the terminus mount nut featuring an internal and shelf saddle design.

[0139] FIG. 123 illustrates the internal saddle design of FIG. 122.

[0140] FIG. 124 illustrates the shelf nut design of FIG. 122

[0141] FIG. 125 illustrates a front view of a fingerboard mounted mechanical adjustable nut.

[0142] FIG. 126 illustrates a back view of a fingerboard mounted mechanical adjustable nut.

[0143] FIG. 127 illustrates an exploded view of a fingerboard mounted mechanical adjustable nut.

[0144] FIG. 128 illustrates a case bottom with pocket geometry for accepting string saddles.

[0145] FIG. 129 illustrates string saddles with a geometry that is complementary to the pocket geometry of the case bottom. FIG. 130 illustrates slot mounted friction fit nut variants for both OEM and vintage style guitars. Note that OEM saddles no longer have a closed end, and the vintage style has a shorter length with an open end.

[0146] FIG. 131 illustrates open end saddles where the saddles extend over the base part.

[0147] FIG. 132 illustrates open end saddles where the saddles extend over the fingerboard.

[0148] FIG. 133 illustrates saddle parts intended for mounting directly onto the fingerboard.

[0149] FIG. 134 illustrates saddle parts mounted directly on the fingerboard.

[0150] FIG. 135 illustrates the geometry that is milled directly onto the fingerboard for receiving saddle parts.

[0151] FIG. 136 illustrates the bottom of the saddle geometry which mates with the milled geometry in the fingerboard or base part.

[0152] FIG. 137 illustrates the exploded view of a friction fit nut. Note the geometry in the base part which mates with geometry on the string saddle parts to guide or align the parts.

[0153] FIG. 138 illustrates a grouping of asymmetric designed friction fit nuts for multiscale guitars.

[0154] FIG. 139 illustrates a standard string saddle design.

[0155] FIG. 140 illustrates an integrated zerofret design where a zerofret is integrated into the string saddle. FIG. 141 illustrates an interchangeable or replaceable zerofret which screws into the string saddle.

[0156] FIG. 142 illustrates a bottom exploded view of the interchangeable zerofrets.

[0157] DETAILED DESCRIPTION

[0158] Set forth below with reference to the accompanying drawings is a detailed description of embodiments of an adjustable guitar nut and variations thereto.

[0159] Disclosed herein are designs for four types of guitar nuts. There may be internally compensated nuts, where the string saddle movements are constrained within the nut body; shelf nuts, where the string saddle movements extend over the fingerboard; zerofret and multi-scale nuts, where the string saddle component is placed on the fingerboard directly in front of the anterior face of the nut; or, locking tremolo nuts, found on locking tremolo guitars such as Floyd Rose, Ibanez, ESP, or others.

[0160] Also disclosed is an acoustic bridge that features similar construction as the guitar nuts.

[0161] In one embodiment of the invention, a fully adjustable guitar nut is disclosed. The fully adjustable guitar nut can incorporate a rack and pinion adjustment mechanism, as may be seen in at least FIG. 1-3 and 6-7. Alternatively, is a fully adjustable guitar nut that incorporates a screw drive adjustment mechanism as can be seen in at least FIG. 4-5, 6 and 8. The rack and pinion mechanism can be adjusted using spring posts which are integrated into a backlash free involute pinion gear design. The design allows for solid contact between the string posts and the nut body. The screw axles may protrude from the nut body. As seen in FIG. 4, the screw adjustment heads of the screw drive mechanism may be countersunk and otherwise embedded into the nut body. An exploded view of the nut is shown in FIGS. 5-7, where a cover plate is shown that is used to mount the nut to the instrument (FIG. 6), and a posterior perspective view of the internal design of the rack and pinion nut variation.

[0162] In another embodiment of the screw drive nut (FIG. 8), the string saddles may be press fit into the adjustment mechanism (FIG. 9). Also included may be a hardened steel rack insert plate which contains geometry for each string slot (FIG. 10). These components may be affixed via screws along the periphery.

[0163] As may be seen in at least Figs. 9-11, the adjustment of the string posts within the string saddles in a linear direction allow for fine tuning of the guitar intonation. The string posts (FIGS. 17, 19) may be adjusted within the spring saddles via the rack and pinion movement of the lower gears of the string posts as the gear teeth interact with the hardened steel rack insert plate. FIGs. 17, and 19 more closely illustrate the integrated involute pion gear and adjustment screw geometry, so it may be understood how the string posts are able to move relative to the nut back and mounting plates.

[0164] The pinion gear nut designs may have 5 components. These include a base, which features geometry to constrain the pinion gear drive; the string saddles, which are integrated with the rack drive; involute gear pinion drives, which also serve as the adjustment mechanism; and screws which may hold the assembly together.

[0165] FIGS. 12-13 show string posts (FIGS. 18-20) which may be adjustable via a screw mechanism. Screw nut designs may have up to six components: nut base, the string saddles, a screw drive axle, which serves as an adjustment mechanism, screws to hold the screw nut in place, and tensioning springs.

[0166] In another embodiment, the involute pinion drive, adjustment post, and string saddle mounting post may be of lower profile (FIG. 11). Alternatively, as seen in FIG. 12, screw drive string support posts may be used in the mounting. FIG. 13 shows the screw drive mechanism, which is held in place with a C-clip or other suitable mechanical means. The body of the nuts may be milled, molded, or cast.

[0167] The mechanism is held in place and encased in the nut body. In this embodiment, the distal end of the screw (opposite the screw head) would interact with a guitar nut backing plate to physically move the string posts in a lateral direction as the screw is turned clockwise or counterclockwise. The screw head may have any known manner of female attachment, such as alien heads, Phillips head, torx head, or flat head, among others. The rack and pinion mechanisms feature driver geometry such as the above female attachment description, or other common driver geometry which is integrated into the backlash free involute pinion ear design. The driver gear integration facilitates production and adjustment. The gear drives the string saddles laterally, or along a Y axis. This design insures solid contact between string posts and the nut body.

[0168] The screw adjustment drive mechanism can be used for both internal and shelf nut designs. In screw drive nuts, saddle movement is adjusted using said screw which is mounted on a recessed portion in the back of the nut body cover plate. The nuts are encased in a housing with a top and bottom portion. They may be milled from a solid material or injection molded.

[0169] In the pinion drive versions, the base housing features pocket geometry to ensure secure attachment of both the pinion gear and the rack drive geometry, affixing it in place.

[0170] As may be seen in FIG. 14, the nut body of either nut may be milled, molded or cast in a solid piece. This piece may be comprised of plastic, metal, or other suitable sturdy material. The nut body of FIG. 14 includes the rack geometry for the rack and pinion nut (FIG. 15).

[0171] The screw adjustment drive mechanism can be adjusted using a screw which is mounted in a recessed manner in the back of the nut body cover plate. The screw may be an alien screw adjustment, or other suitable screw. The nut may be milled from a solid material, with only material to house the mechanisms being removed. The nut may also feature a cover design which is used to mount the nut on the instrument.

[0172] In additional embodiments, the rack and pinion mechanism sits in a pocket and the base part is secured and held in place by a top nut partition, to allow better surface contact with the nut body and less material to be removed. There may also be a top closure method of the nut on both pinion drive and screw drive nuts, where the top closure has 2 methods: screws from the top, or screws from the side (as in the Zerofret nut example).

[0173] In another preferred embodiment, the pinion drive nut has a locking nut (FIG. 21). The zerofret example is shown in at least FIG. 22, where a zerofret guitar nut may have string saddles extending over the fingerboard. FIG. 23 shows a standard shelf nut with a string partition extending over the fingerboard. A detailed view of the shelf nut (FIG. 25) shows additionally the string slots used for guiding strings and the embedded alien key adjustment. The top partition of the shelf nut (FIG. 25) is held in with screws to the mechanism of the nut with pinion gear drives and rack guided string partitions (FIG. 26) and eventually to the base part of the nut (FIG. 27). Note that pocket geometry of the base of the nut which is complementary to the pinion gear drives and used to fix the pinion gear in place.

[0174] Another embodiment is shown in FIGS. 28-30, where a zerofret nut perspective view may be seen. The top partition of the nut (FIG. 29) contains string guide slots and is affixed via screws mounts on the side to the mechanics of the nut (FIG. 30), containing the adjustable portions.

[0175] In yet another embodiment, a multiscale nut may be used where the nut is mounted at an angle (FIGS. 31-33). The internals of the multiscale nut (FIG. 32) align with the base part of the nut (FIG. 33) with geometry for the pinion gear.

[0176] In a different embodiment, it may be desired to use a locking tremolo nut assembly (FIGS. 34-35). The locking assembly includes a base portion with removable upper tabs for fixing the strings, and another screw to cinch the tabs along the base portion to prevent string movement.

[0177] An adjustable guitar nut of a different embodiment is shown in FIGS. 36-40, which show an assembled base part of the locking nut with adjustment screws. FIG. 36 is the entire assembly, with the exploded parts shown in FIGS. 37-40. In this embodiment is an interior portion containing the pinion gear retention geometry (FIG. 37). Also shown are the pinion gears (FIG. 39) which serve to adjust the individual string saddle posts of FIG. 39 which extend over the fingerboard when adjusted. FIG. 40 shows the top of the nut which may be held in place via screws to create the entire nut assembly (FIG. 36).

[0178] FIG. 41 more closely shows an embodiment of an extended string saddle partition of the screw drive shelf nut, along with the nut body (FIG. 42) of the screw drive shelf nut and the placement of the drive screws for the screw drive shelf nut (FIG. 43). The screws are held in place via c-clip or other suitable retaining means.

[0179] In another embodiment, an encased adjustable shelf nut is shown (FIG. 44). This exploded view of the encased adjustable shelf nut shows the screws (FIG. 45), the nut base part of the screw drive shelf nut (FIG. 46) and the string saddle partitions (FIG. 47). Note the pockets for the screw drive mechanics of the nut base part of the screw drive shelf nut, which exactly encase the mechanism used to minimize vibrations. Here also, the top of the nut (FIG. 48) may have integrated string slots. The top of the nut may also be hollowed in the middle to avoid excessive string contact with the nut.

[0180] FIG. 49 shows an embodiment of an adjustable acoustic guitar bridge according to an aspect of the disclosure. The complete assembly is mounted to the instrument opposite the nut. FIG. 50, alternatively, illustrates a bridge assembly which may be internal and mounted inside the wooden guitar bridge body. FIGS. 51-54 show an alternative, exploded view of the acoustic guitar bridge assembly to see the individual string saddle partitions which may be press fit onto the rack drive string saddle posts. The bridge base unit may have pockets milled to house the rack and pinion mechanism driving the saddles, and a cover plate is used atop the entire assembly. The assembly sits along a wooden block (FIG. 54) which encloses the bridge internal assembly inside the wooden guitar bridge body. As may be seen in FIGS. 55-56, a detailed view of the rack and pinion mechanism of the adjustable bridge is shown where the pinion drive is offset and sits outside of the rack drive.

[0181] Additional embodiments show fully adjustable nuts which incorporate both rack and pinion and screw drive adjustment mechanisms. The nuts are acceptable for both uni and multi scale instruments, and include: a screw drive top partition nut, where the entire top of the string saddle moves; a screw drive Zero Fret nut, where the zero-fret partition moves, and the top partition is stationary; a combination screw drive and top partition nut, where both the Zero fret and top partition move in unison; an adjustable fingerboard mounted rack and pinion drive Fender style nut; an adjustable fingerboard mounted rack and pinion drive zerofret nut; an adjustable fingerboard mounted rack and pinion drive zerofret and integrated nut; and, an adjustable fingerboard mounted Screw drive nut for Fender and Zero fret.

[0182] Central to all the nuts are that they are fully enclosed, and that the internal geometry of the nut body matches the geometry of the string saddles. This maximizes the contact area between the string saddles and the nut body which improves resonance and transfer of vibrational energy. Performance is also optimized by minimizing the amount of empty space within the nuts, and by maximizing the contact area between the different components of the nut.

[0183] In one preferred embodiment, the nut variant featuring top partition movement is selected. Additionally, in a preferred embodiments the interior of the nut cavity is matched with the string saddle drive geometry. It is possible to use geometry that differs in shape and is not in physical contact with the walls of the nut cavity however this would yield inferior sonic performance. The rack and pinion mechanism in the fingerboard mounted nut sits in a pocket in the base part and is secured and held in place by the top nut partition. This design offers better surface contact with the nut body and less material need to be removed to hose the mechanism in comparison to the screw drive units. It is also preferred to mill the nut from a solid material to improve mass and resonance rather than casting or molding the nut body. For the Fender nut rack and pinion design our preferred embodiment has the Nut saddle partitions facing forward and the adjustment screws facing towards the headstock. For the Fender screw drive nut, in our preferred embodiment both the top and the bottom of the nut case together form the hollow section which houses the screw drive partition blocks. Both the top and the bottom sandwich the drive block and apply pressure and constrain the part. It is possible to have a flat top and hollow out only the bottom of the nut case, however in our preferred embodiment both the top and bottom have a recess pocket.

[0184] FIG. 57-58 show an embodiment for a screw drive top partition movement adjustable nut, with top mounting covers for proper installation. FIGS. 59-60 show a screw drive top partition movement adjustable nut with radius of the mating of the top partition to match the nut body and fingerboard. FIG. 60 more closely shows the interior of the screw drive mechanism top partition movement and cover, with interlocking geometry of the string saddle drive partitions, which are more closely shown in FIGS. 61-62 and 66-68.

[0185] FIGS. 63-65 illustrate a screw drive top partition movement nut for a multiscale instrument, a screw drive zerofret partition movement nut for a multiscale instrument, and a combination screw drive zerofret and top partition movement nut for a multiscale instrument. The offset saddle partitions are unlike a uni-scale guitar nut, where a multi-scale guitar nut is mounted on the instrument at an angle and the movement of the partitions follows the y-axis, or string lateral direction. In the zerofret embodiment, the top of the nut is stationary. In the combination zerofret and top partition movement, the zerofret and top partition of the nut move in unison.

[0186] The screw drive zerofret partition movement nut may be mounted as shown in FIGS. 69- 70, with the interior details of the nut shown in FIGS. 71-72. Note the nested rack and pinion mechanism again used in the nut of FIG. 71 and the zerofret fingerboard mounted nut of FIG. 72.

[0187] Also included may be interior pockets located in the nut base, holding the rack and pinion drive unit (FIGS. 73-75). These are used with guitars that may have a radiused fretboard, where the pocket housing the rack and pinion mechanism mates with the pocket located on the bottom of the top of the nut case. The pocket formed by both the top body of the case precisely matches the dimensions and apply pressure to the rack drive mechanism. In the case of a flat non radiused fingerboard then the pocket housing the rack drive mechanism is contained to the bottom base part, the flat bottom of the top of the nut case housing applying pressure to the rack drive and pinion gear parts. The geometry may be held in place as is shown in FIGS. 76-77, and the way it is affixed to the fingerboard is shown in FIGS. 78-79. Specifically, FIG. 79 shows a nut design for Fender Stratocaster and Telecaster guitars. The internal design is the same as the fingerboard mounted zero fret nut. The difference between the zero fret and the fender version is that the Fender features string partitions with slotted geometry to hold the strings in place in the X axis.

[0188] The zero fret is simply a metal fret with no string slots. The fender pinion nut, adjustment screws for fender pinion nut, screw drive nut are further shown in FIGS. 80-86.

[0189] In addition, it is contemplated a family of adjustable nut designs which share friction fit interaction mechanism. The adjustable nuts may be used in uniform and multi-scale instruments. Such embodiments include: Friction fit adjustable saddle shelf nut design for fingerboard terminus mounted nuts; Friction fit adjustable saddle shelf nut design for slot mounted nuts; Friction fit adjustable saddle shelf nut design for asymmetric multiscale instruments; Friction fit adjustable saddle shelf nut design for locking type nuts; or Friction fit adjustable nuts for fingerboard installation.

[0190] All the nuts feature a base part with fingerboard matching radius and adjustable saddles which move and extend over the fingerboard in the Y axis direction, the string saddles mate interact with a base piece via a clearance fit and are retained in place with fasteners.

[0191] The nut base parts may feature male guide pin geometry which protrude from the part and mates and interacts with the female geometry of the saddle partitions. These in turn feature channels of matching geometry which create a clearance fit and help guide Y axis movement and improve the mating of the parts and therefore resonance.

[0192] The locking nut design features female molded cavities which create a clearance fit with the male saddle partitions parts. The saddle parts feature a male cam geometry which both guides the part, and which are used to lock the saddle partitions in place using grub screws. The fingerboard mounted nut features a 2-part base design which allows the concealment of the mounting holes. The bottom portion of the base part features channels which mate, interact and guide the saddle partitions parts with a clearance fit and the top portion of the base parts features geometry which interacts with string partitions via a clearance fit which helps secure the string partitions and improves resonance.

[0193] While it is possible for the top mounted sliding saddle partitions to feature the male geometry and the base part female geometry, in our preferred embodiment the nut base part is male and the string partitions female. For the fingerboard mounded nuts our preferred embodiment has grub screws mounted behind the saddle partitions facing towards the headstock. It is possible to reverse this design and feature the grub screws mounted flush with the fingerboard in front of the saddle partitions.

[0194] FIG. 86-89 show an embodiment for an adjustable fingerboard terminus mounted nut for inflexible, high tension or strain strings. FIGS. 88-89 more closely shows the anterior view of the adjustable slot mounted nut.

[0195] FIGS. 90-93 shows a possibility of three different embodiments: terminus mounted, symmetric slot mounted and asymmetric slot mounted nut designs. Each has differing curved radii on the different designs which are designed to sit flush with the fingerboard. There may be a nut base part featuring male geometry to mate with female geometry on the underside (FIG. 93) of the string saddle parts, which are affixed with fastening screws (FIG. 92) of the saddle partitions to the base part. FIGS. 94-95 show another view of the saddle partitions and the female slot geometry for mating with the male top geometry to assist in guiding the part to fit via clearance. Alternatively, the terminus mounted nut may feature a single male geometry on the string saddle part and a single female geometry in the base part. The installation is shown in FIG. 96-97.

[0196] In another embodiment, a friction fit locking nut is contemplated. The front of the nut has recesses to permit saddle partitions to move in the negative Y-axis to meet with the fingerboard (FIG. 98). An exploded view is shown in FIGS. 99-103, where it may be seen the individual string saddle partitions of the locking nut along with the cam geometry which is complementary to the geometry in the base portion. Locking tabs may also be used to lock strings in place via grub screws which interact with the cam geometry on strong partitions.

[0197] FIGS. 104-105 show how, in certain embodiments, the string saddles may be clearance fit between the nut body and how it may be mounted on a guitar, where the underside of the string saddle partitions match and sit atop the guitar’s fingerboard.

[0198] In some embodiments, the friction fit locking nut may be fit to the guitar as shown in FIG. 106, where the recessed cavities of the nut body permit travel for the individual string saddle partitions (FIG. 107).

[0199] As shown in FIGS. 108-112, the nut case bottom piece can have a bottom piece, top part, case screws, and grub screws to lock string partitions in place. The clearance fit interaction between the string saddle cam geometry and the geometry in the nut case is shown. Note that the cam thickness of the individual string saddle piece may differ and follow the radius of the part and fit the volume of the cavities formed in the nut base two-part clamshell assembly.

[0200] In some embodiments, the cam geometry of the string saddle partitions (FIG. 113) may share a clearance fit in the cavity formed by the assembly of the nut case bottom part and the nut case top part. Note that the protruding geometry on the underside of the nut case top part. This geometry is designed to interact via a clearance fit with the top surface of the cam geometry of string saddle partitions.

[0201] Additionally, in another embodiment a terminus mounted (end of fingerboard) mechanical adjustable nut family is contemplated. The nut may be a stamped metal version with a U-shaped nut body profile having internally adjustable saddles (FIGS. 117-118). The shelf nut version may have saddle partitions that extend over the fretboard (FIG. 120). The terminus mount nut may have both internal or shelf nut designs (FIGS. 121-124). The pocket geometry is applied here as well to accept string saddles, where the string saddle has geometry which fits into the pocket geometry of the case bottom. (FIGS. 125-129).

[0202] In another embodiment, the slot mounted nuts may be friction fit variants used in both OEM and vintage style guitars, where the OEM saddles are longer and have a closed end, and the vintage style is shorter in length with an open end. The saddles may extend over the base part, or over the fingerboard. (FIGS. 130-132). They may be mounted directly onto the fingerboard (FIG. 133, 134), and may be fit via complementary geometry that is milled directly into the fingerboard (FIGS. 135-136). The friction fit nut is shown more closely in FIG. 137, where the geometry of the base part mates with the geometry of the string saddle part which guides or aligns the parts along the fingerboard. Different designs, of asymmetric fit, standard fit, zerofret design, and interchangeable or replacement designs, are also contemplated and shown herein in FIGS. 138-142.

[0203] As used herein, “including,” “containing” and like terms are understood in the context of this application to be synonymous with “comprising” and are therefore open-ended and do not exclude the presence of additional undescribed or unrecited elements, materials, phases, or method steps. As used herein, “consisting of’ is understood in the context of this application to exclude the presence of any unspecified element, material, phase, or method step. As used herein, “consisting essentially of’ is understood in the context of this application to include the specified elements, materials, phases, or method steps, where applicable, and to also include any unspecified elements, materials, phases, or method steps that do not materially affect the basic or novel characteristics of the invention.

[0204] For purposes of the description above, it is to be understood that the invention may assume various alternative variations and step sequences except where expressly specified to the contrary. Moreover, all numbers expressing, for example, dimensions used in the specification and claims, are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents, each numerical parameter should at least be construed considering the number of reported significant digits and by applying ordinary rounding techniques.

[0205] Any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of “1 to 10” is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value of equal to or less than 10.

[0206] In this application, the use of the singular includes the plural and plural encompasses singular, unless specifically stated otherwise. In addition, in this application, the use of “or” means “and / or” unless specifically stated otherwise, even though “and / or” may be explicitly used in certain instances. In this application, the articles “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent.

[0207] Whereas embodiments of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.

Claims

What is claimed is:

1. An adjustable guitar nut comprising a rack and pinion adjustment mechanism.

2. An adjustable guitar nut comprising a screw drive adjustment mechanism.

3. The adjustable guitar nut of claims 1 or 2, wherein the guitar nut body is milled from a solid material.

4. The adjustable guitar nut of any of the preceding claims, wherein the guitar nut back plate functions as a mounting plate.

5. An encased adjustable guitar nut with internal adjustment values.

6. The encased adjustable guitar nut of claim 5, further comprising a rack and pinion adjustment mechanism.

7. The encased adjustable guitar nut of claim 5, further comprising screw drive mechanisms.

8. The encased adjustable guitar nut of any of claims 5-7, where a plurality of string saddles extends over a fingerboard.

9. The encased adjustable guitar nut of any of claims 5-8, wherein the guitar nut is a zerofret / multi scale nut.

10. The encased adjustable guitar nut of any of claims 5-9, wherein the rack and pinion nuts for locking tremolo guitars with the string saddles extend over the fingerboard.

11. An adjustable acoustic guitar bridge with rack and pinion drive mechanism.

12. An acoustic guitar equipped with an adjustable acoustic bridge of claim 11 and an adjustable guitar nut of claims 1, 2, or 5-7.

13. An electric guitar equipped with an adjustable guitar nut of claims 1, 2, or 5-7.

14. An encased adjustable guitar nut of claim 5 further comprising a screw drive adjustment mechanism with top partition movement.

15. An encased adjustable Zero-fret guitar nut featuring a screw drive adjustment mechanism with stationary top partition and zero-fret movement.

16. An encased adjustable Zero-fret guitar nut featuring a screw drive adjustment mechanism with Zerofret and Top partition movement.

17. An encased adjustable guitar shelf nut featuring screw drive mechanisms, wherein the string saddles match the radius and extend over of the fingerboard.

18. The encased adjustable guitar shelf nut of claim 17, further comprising Zero-Fret partition saddles extending over the fingerboard.

19. A screw drive nut wherein the nut body geometry which matches a saddle drive geometry.

20. An encased nut design with a hollowed-out nut body and a cover which seals the unit.

21. The encased nut design of claim 20, wherein the hollowed-out nut body and covers have differing bottom thickness to facilitate installation.

22. A fingerboard mounted rack and pinon drive zero-fret intonation partition, wherein the drive screws in front of or behind the zerofret.

23. A fingerboard mounted rack and pinon drive zero-fret nut with intonation partitions and integrated string partitions, wherein the nut drive screws in front of or behind the zerofret.

24. A fingerboard mounted rack and pinon drive fender style nut, wherein the drive screws in front of or behind the intonation partitions.

25. The fingerboard mounted rack and pinon drive fender style nut of claim 24, wherein the partitions that extend over the fingerboard.

26. An adjustable guitar nut for fingerboard terminus installation, wherein the nut comprises a base part having same height and thickness as the fingerboard, and; the entire nut having curved top geometry that sits flush with and matches the radius of the fingerboard.

27. A symmetric adjustable guitar nut for slot installation, comprising a base part having same height as the depth of a slot in a fingerboard so that the curved top geometry of the part sits flush with and matches the radius of the fingerboard.

28. The adjustable guitar nut of any of the preceding claims, comprising a base part having male geometry which mates and interacts with a clearance fit female geometry molded into the underside of the part, such as a pin and slot design.

29. An adjustable locking guitar shelf nut comprising a molded or milled female geometry in the base part which mates with male string partitions via clearance fit.

30. The adjustable locking guitar nut of claim 29, wherein the male string partitions are secured via grub screws.

31. An encased fingerboard installed guitar nut comprising a two-piece nut body construction; wherein the bottom piece has female channels which house and mate with male saddle partition parts cam geometry via clearance fit, and wherein a top piece interacts with the Male saddle partition parts cam geometry via clearance fit.

32. An encased fingerboard installed guitar nut, comprising a one-piece nut body featuring female channels which house and mate with the male saddle partition parts cam geometry via clearance fit.

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