LINEAR DOVELT NECK JOINT FOR MUSICAL INSTRUMENTS and MUSICAL INSTRUMENT

Abstract

Linear dovetail neck joint for a musical instrument (1) with a body (2), wherein the linear dovetail neck joint has the following features: a neck (4) with a lower surface (5b) with a groove (30); a block (40) with a contoured surface (46) which forms part of the body (2) when the block (40) is attached to the body (2), an upper platform (42) with a hole (52a, 52b) accessible from outside the musical instrument (1) and configured to receive a fastening element (54a, 54b), and a rear surface (48) with a window (60); a compensating sleeve (70) designed to be inserted into the window (60) of the block (40); at least one substantially flat or angled compensating washer (90) configured to fit into the compensating sleeve (70), the compensating washer (90) having an upper section (96a, 96b) with a height defining the distance by which the linear dovetail neck joint separates the neck (4) from the block (40) when the lower face (5b) of the neck (4) rests on the upper section (96a, 96b) when the linear dovetail neck joint is fully assembled; and a dovetail tenon (110) which engages at least indirectly in the groove (30) of the neck (4) and has a top (116), a bottom (118) and an opening (112a, 112b) extending through the dovetail tenon (110) from the top (116) to the bottom (118), wherein the opening (112a, 112b) is aligned with the hole (52a, 52b) of the block (40) and is configured to receive the fastener (54a, 54b), and wherein a rotation of the fastener (54a, 54b) in the opening (112a, 112b) causes the fastener (54a, 54b) to pull the dovetail tenon (110) together with the neck (4) downwards towards the upper platform (42) of the block (40) and the dovetail tenon (110) and neck (4) attached to the block (40).

Description

TECHNICAL AREA

[0001] The present invention relates generally to the neck joint of a stringed musical instrument, such as a guitar, and in particular to a neck joint which facilitates linear and angular adjustments between the neck and the body of the instrument connected by the neck joint. BACKGROUND TO THE DISCLOSURE

[0002] Music plays an important role in our daily lives and is embedded in the fabric of society. Many people make music for leisure, as a hobby, or as a profession. Chordophone instruments are musical instruments that produce a sound through one or more vibrating strings stretched between two points. Chordophone instruments, especially stringed instruments, are very popular worldwide because of their versatility and suitability for various musical genres. The most popular stringed instrument is probably the modern guitar, which comes in both acoustic versions, producing sound acoustically, and electric versions, producing sound through electrical amplification.Conventional acoustic and electric guitars consist of a body and a neck, which is connected to the body by a joint, with one or more elongated, flexible strings running between the body and a distal end of the neck along a fretboard. (The terms "distal" or "distal end" are used to define the part or surface of an element that is furthest from the player.)

[0003] There are three general types of neck joints used on stringed instruments. "Through-neck" instruments have a neck that extends completely through the instrument and is almost always glued in place. "Set-neck" instruments also have a glued neck with a mortise and tenon or dovetail joint where the body meets the neck. These instruments typically have a neck shoulder just in front of the body that extends to the back of the body for support. Finally, there are "bolted" instruments (screwed on would actually be more accurate), which have an opening in the body where the neck overlaps, and where bolts (or screws) connect the neck to the body. With this type of instrument, the neck joint is usually fixed, so no movement between the neck and body is possible during use.However, the bolts can be loosened so that the neck can be removed from the body or repositioned.

[0004] Acoustic guitars are traditionally set-neck instruments, where the neck joint sits directly in front of the body and extends to the back. This forward projection under the neck, next to the body, restricts access to the highest part of the fretboard while playing. Electric guitars are generally either set-neck or bolt-on. Conventional bolt-on instruments are inexpensive to build and repair. The disadvantages of existing bolt-on designs are that the joint has less lateral stiffness than set necks, and that access to the highest part of the front of the fretboard near the body is restricted because the body section runs under the overlap of the neck.Given the disadvantages of bolt-on neck constructions, the neck of most conventional acoustic and electric guitars is permanently attached to the body during manufacturing and assembly. A general drawback of such permanent attachment mechanisms is that the neck cannot be easily moved away from the body to conveniently adjust the guitar's characteristics.

[0005] As is well known in the guitar world, the most important quality characteristics of a guitar are its tone (i.e., the audible nature of the instrument, including volume, brightness, evenness, pitch separation, etc.), its playability (i.e., the instrument's ability to respond to the player's technique), and its durability (i.e., the instrument's ability to retain its tone and playability over years and decades). The neck joint is important for each of these three guitar characteristics. The following briefly discusses how the neck joint affects a guitar's tone, sustain, and playability.

[0006] Regarding sound, the transmission of vibrations is crucial for the tone or sound of a guitar. The point where the neck and body meet (i.e., the neck joint) forms a kind of "sound intersection." Thus, the neck joint is an important part of the sound transmission within a guitar, where treble, bass, midrange, fundamental tones, and all forms of overtones determine whether they pass through or are deflected. Depending on the type of neck joint, the result of this physically determined filtering system largely determines the guitar's sound.

[0007] The term "sustain" is meant to be a measure of the duration of musical sound. Specifically, "sustain" refers to the length of time the guitar's sound continues before it fades away. A guitar's sustain is reduced by the conventional mechanisms used to attach the neck and body. Generally speaking, the more rigid the mechanical connection between the neck and body of a guitar, the longer the guitar's sustain. Furthermore, a rigid mechanical connection between the neck and body typically improves the quality and consistency of the sound produced by the guitar. It is therefore desirable to have a largely rigid mechanical connection between the neck and body of a guitar. This also explains why most guitars manufactured today are still built with a neck that is firmly fitted and glued into the body (i.e.,Guitars with a set-in neck).

[0008] Finally, playability must be considered. Crucial to the playability of a stringed instrument is the distance of the string above the neck. The height of the string in relation to the neck and the fretboard is commonly referred to as the "string action." Generally, the desired string action on a guitar depends on the player's personal preference. Some musicians prefer a smaller distance between the fretboard and the strings, or a "low" string action, while others prefer a high action. If the string action is too high, playing becomes difficult and uncomfortable and, in extreme cases, can lead to injuries from repetitive strain. If the string action is too low, the strings buzz against the frets or even rest on them, generally rendering the instrument unplayable.Generally speaking, tiny differences in string height above the neck can make a big difference in performance for both amateur and professional musicians. The acceptable range for string action is quite small—perhaps 2.5 mm (0.1 inch) or so.

[0009] Given this narrow range, guitars must be built with extreme precision in their neck joints and maintain this critical geometry under the stress of up to 180 pounds of string tension over time. On a traditional guitar, the string action is typically set at the factory, and any adjustments must be made by a skilled technician. Furthermore, traditional guitars usually have very limited action, and significant changes to the instrument's string height can only be achieved by altering the structure of the body or neck. These types of modifications can be quite costly and can significantly affect the guitar's long-term performance. Therefore, it is desirable to have a musical instrument that allows the user to adjust the string action quickly and efficiently.

[0010] On several well-known stringed instruments, the string action is adjusted by changing the angle between the neck and body. These instruments operate on the principle that a larger angle lowers the string action, while a smaller angle raises it. The string action can be raised or lowered by adjusting the angle between the neck and body of the guitar. However, changing this angle also affects the intonation, tonal characteristics, and scale length of the guitar strings. The disadvantage of these designs is that the user cannot adjust the neck's string action without altering the guitar's intonation and tone.

[0011] For example, US Patent No. 6,051,766 A discloses a guitar in which the neck angle relative to the guitar body is changed by placing washers of varying widths in the guitar cavity where the neck is attached to the body. Another adjustable neck is disclosed in US Patent No. 6,265,648 B1, which provides a neck attached to the guitar body by a spring-loaded clamping device that creates a pivot point allowing movement of the neck at an angle relative to the body. Neither of these devices allows the user to adjust the linear direction of the neck without also changing the angle of the neck relative to the body. Furthermore, Patent 6,051,766 A requires the user to remove the neck from the guitar body to adjust the string action. Additionally, Patent 6,265,648 B1 relies on the preload of a spring to hold the neck in position.This spring tension can weaken over time, causing the neck to become unstable. The force exerted by the spring also creates an upward force on the neck-body joint, which can damage various components of the guitar. Therefore, it is desirable to have a neck that can be easily adjusted linearly without changing the angle at which the neck extends from the body.

[0012] A rigid guitar structure is generally excessively heavy and can negatively affect the sound. A lighter guitar construction tends to sound better, but carries the risk of the neck warping over time, changing the string action to the point where the neck eventually needs to be readjusted, typically resulting in a costly repair of several hundred dollars. Accordingly, the sound, playability, and durability or sustain of a guitar are fundamentally at odds with one another, and compromises often have to be made in its construction. Some luthiers consider a balance of these three qualities desirable.

[0013] Even after a luthier has finished making a guitar, the user may still want to change its characteristics. Musicians often desire a guitar with different features for various reasons. The ease and comfort of playing, as well as the tone or sound produced by a guitar, depend heavily on the characteristics of the neck. Currently, the only practical way to change a guitar's characteristics is to use a different guitar with a different configuration (including the type of neck joint). Using multiple guitars with different configurations is not only expensive but also complicates storage and transport.

[0014] Guitars are mostly made of wood, and wood tends to shrink over time, both under string tension and in response to daily fluctuations in humidity. For example, a guitar that has a comfortably low action in Houston, Texas, might shrink so much during a winter flight to Minneapolis, Minnesota, that it becomes unplayable. The luthier has to anticipate that the guitar will spend some time in low humidity, so the instrument needs a sufficiently high action to remain playable under all foreseeable conditions. Unfortunately, the action is usually not optimal in higher humidity.

[0015] Therefore, guitars typically have a higher action than ideal to accommodate the possibility of the instrument eventually being exposed to low humidity. As string tension gradually deforms the wood structure over time, the action is likely to increase and eventually deteriorate. Changing the action of a guitar, whether by the musician, owner, technician, or repairer, is generally complicated by the fact that many guitars have fixed necks, which limit the range of relatively easy adjustments.

[0016] One way to change the action of a fixed-neck guitar is to unstrung it, then remove and shave down the bridge. Since the bridge height is usually quite low, a significant amount of material needs to be shaved down to actually affect the action. Furthermore, adjusting the bridge height can only temporarily resolve the issue. Additionally, a shorter bridge reduces the leverage the strings have to vibrate the top of the guitar body, thus negatively impacting both the tone and volume of the guitar to some extent.

[0017] Often, a musician, owner, technician, or repairer will attempt to adjust the truss rod. A truss rod generally consists of a threaded rod with nuts at both ends, running parallel to another rod or bar. By turning the threaded rod in one direction or the other, the truss rod will eventually begin to bend, causing the neck and its associated fretboard to bend accordingly. It goes without saying that using the truss rod to compensate for anything more than a tiny rise is generally a bad idea, as such adjustments frequently result in a broken truss rod, which usually leads to the guitar being discarded by its owner.

[0018] Some luthiers have incorporated various mechanisms to adjust the geometry of the neck joint. More than a century ago, they experimented with adjustable neck joints. A number of luthiers still use neck joints today that can be adjusted in one way or another. However, given their drawbacks, only a small percentage of all guitars are equipped with such neck adjustment systems.

[0019] The most common approach is to slightly "tilt" the end of the neck relative to the body, that is, to pivot it where the neck heel meets the body. This pivoting is controlled by a screw that extends through the neck heel into the body well below the pivot point. Turning the screw in a first direction pushes the neck heel further away from the body and moves the headstock backward, thus reducing the distance between the strings and the fretboard and lowering the action. US Patent No. US 7,157,634 B1 discloses an example of this approach. Because the pivot point is well below the plane of the strings, such a tilt also increases the distance between the nut and the bridge.The adjustment mechanism requires considerable force, as the strings are already under tension of approximately 180 pounds. Therefore, it may be necessary to remove the strings before attempting any adjustments. In any case, any stretching or loosening of the strings will change their pitch, requiring the player to retune the guitar after the adjustment. It's important to remember that with a larger adjustment, the distance between the nut and bridge can change so much that the new effective scale length no longer aligns with the fretwork, resulting in an out-of-tune instrument. To utilize this principle as effectively as possible, the adjustment range should be set by the manufacturer in the middle of its possible travel to allow adjustments in both directions.

[0020] Another approach is to raise and lower the entire neck relative to the guitar body, for example, using a sliding mortise and tenon joint. Such a system is described in US Patent No. US 7,557,281 B1, although other lifting or "elevator" systems are available and known in the trade. With elevator systems, the strings are also typically stretched or loosened, but to a lesser extent than with the tilting systems described above. Even if the direction of movement is very close to being exactly perpendicular to the plane of the strings, some stretching or loosening of the strings typically occurs, which changes the pitch of the strings.

[0021] Although neck and body parts have traditionally been molded as a single integral unit, a variety of guitars exist where the neck and body are made from separate pieces joined together to form the instrument. A number of neck and body attachments are known in engineering. Each of these attachments presents a number of problems. Among other things, existing attachments can be difficult to install, expensive to assemble, structurally unstable, and aesthetically undesirable. Therefore, there is a continuing need for improved methods and devices for attaching the neck and body. In particular, there is a need for a highly practical and mass-producible neck attachment or joining mechanism that allows for easy adjustment of the neck position in the plane of the body surface.

[0022] US Patent 4,793,236 A discloses a self-adjusting neck joint for the detachable attachment of an electric guitar neck to the guitar body, which secures the neck in the correct alignment with the body. The neck joint comprises a first bracket that mounts in a channel on the underside of the upper end of the neck, and a second bracket that engages in a neck recess in the guitar body. Engaging the brackets securely attaches the neck to the body and fixes it in the correct alignment. Both brackets feature a pair of rows of interlocking undercut teeth, with one row on the second bracket being transversely movable to selectively engage or disengage from the corresponding teeth of the first bracket. This allows the brackets to be disengaged and the neck to be separated from the body.A screw-controlled, movable wedge on the second bracket presses the movable teeth into firm engagement with the teeth of the first bracket, thus ensuring a precise and firm fixation of the neck in the correct alignment to the guitar body.

[0023] US Patent 7,893,328 B1 discloses a frame construction for a stringed instrument comprising a body with a first interlocking joint on one outer surface, and a neck with a second interlocking joint at its proximal end. A key is also provided, consisting of a first and a second section. One section of the key engages the first joint on the body, while the other section engages the second joint at the proximal end of the neck. This at least partially connects and secures the body and neck through the interlocking of the parts with the key.

[0024] US Patent 5,886,272 A depicts a guitar neck featuring a trapezoidal, protruding heel that engages in a recess at the end of the body. The movement of the heel within the recess is limited by the recess's side walls and by a lip extending from the bottom of the recess and connecting to the upper portion of the neck above the heel. BRIEF SUMMARY OF THE DISCLOSURE

[0025] To meet these and other requirements and overcome the shortcomings of existing neck joints, a linear dovetail neck joint for musical instruments is provided. One objective of this disclosure is to enable quick and easy adjustment of the relative height and angle of the neck with respect to the body of the stringed instrument, so that the string action and intonation can be easily changed by the user or musician. A related objective is to have a neck that can be easily adjusted in a linear direction without affecting the angle at which the neck extends from the body. Another objective of this disclosure is to provide a neck joint that attaches the neck to the body with a rigid mechanical connection.Another goal is to provide a neck joint that does not impair the musical tone or sound, playability, or sustain of the instrument.

[0026] To achieve these and other goals, the present disclosure offers a linear dovetail neck joint for a musical instrument with a neck, body, and fingerboard. The linear dovetail neck joint is based on an internal dovetail with screw-adjustable tension, thus avoiding screws that go directly into the neck. The linear dovetail neck joint allows for extremely high fret accessibility in the upper register of the fingerboard (due to the absence of a shoulder on the neck), easier neck height adjustment, intonation correction, and unique front block configurations with hand relief—all without the need for adhesives. The linear dovetail neck joint provides a practical and aesthetically pleasing neck-body connection without requiring a shoulder on the neck.The result is a neck-body connection that is easily adjustable and maintainable.

[0027] More precisely, the linear dovetail neck joint for a musical instrument comprises a neck with a bottom surface featuring a groove. A block has a contoured surface that forms part of the instrument's body when attached, a top platform with a hole accessible from outside the instrument and configured to receive a fastener, and a rear surface with a window. A filler sleeve is designed to fit into the window in the rear surface of the block.At least one substantially flat shim is configured to fit into the shim sleeve, the shim having an upper section with a height that defines the distance by which the linear dovetail neck joint separates the neck from the block when the lower face of the neck rests on the upper section of the shim when the linear dovetail neck joint is fully assembled. A dovetail tenon engages, at least indirectly, in the groove of the neck and has a top, a bottom, and an opening extending through the dovetail tenon from the top to the bottom. The opening is aligned with the hole in the block and designed to receive the fastener.The rotation of the fastener in the opening causes the fastener to pull the dovetail tenon, along with the neck, downwards towards the upper platform of the block, securing the dovetail tenon and neck to the block.

[0028] More precisely, the linear dovetail neck joint consists of two main components: a modified neck and a block with a contoured surface that forms part of the body when the block is attached. An intonation screw moves the neck relative to the body, adjusting the intonation of the instrument. The neck has a top surface with a through-hole for a truss rod and a bottom surface with a groove and at least two slots. In addition to (i) the contoured surface that forms part of the body when the block is attached, the block has (ii) a bottom surface, (iii) a top platform with a recess, a first hole extending from the top platform through the bottom surface and aligning with a third hole in a rear plate of the body, accessible from outside the instrument and configured to accept a first fastener.a second hole extending from the upper platform through the contoured surface and accessible from outside the musical instrument, configured to accommodate a second fastener, and at least two alignment openings, one alignment opening being aligned with and corresponding to each of the at least two slots in the lower surface of the neck when the linear dovetail neck joint is fully assembled, and (iv) a rear surface comprising a window, an opening configured to accommodate the intonation adjustment screw, and an access point aligned with the passage in the upper surface of the neck and configured to accommodate the truss rod.

[0029] At least two alignment pins are provided. One alignment pin is partially inserted into each of the at least two alignment holes in the upper platform of the block and into the aligned and corresponding slots in the lower surface of the neck when the linear dovetail neck joint is fully assembled. The alignment pins align the neck with the block and prevent side-to-side movement of the neck.

[0030] The linear dovetail neck joint comprises, in addition to the main components of the neck and block, a number of separable components. These separable components include a compensating sleeve, one or more compensating washers, a dovetail tenon, a spring cage, and a dovetail slide. Each of these components is summarized in terms of its interaction with the neck, the block, and the other separable components.

[0031] The compensating sleeve is configured to fit into the window formed in the back face of the block. The compensating sleeve has a front face, a bottom with a raised rib to ensure correct alignment, and side walls, each with a corresponding slot.

[0032] At least one substantially flat shim is configured to fit into the shim sleeve and engage with the shim in a close friction fit. The shim has a top section with a height that defines the distance by which the linear dovetail neck joint separates the neck from the body when the lower surface of the neck rests on the top section of the shim when the linear dovetail neck joint is fully assembled; a bottom with a track configured to receive the rib of the shim; and side walls, each with a corresponding flexible, spring-like latch. Each latch includes a first projection designed to engage in corresponding slots in the side walls of the shim when the shim is fully seated in the shim.A second projection extends a short distance beyond the front of the compensating sleeve and protrudes into the neck pocket when the compensating washer is fully inserted into the compensating sleeve.

[0033] The dovetail tenon has a top, a bottom, and a central longitudinal axis with a first opening and a second opening, each aligned along the axis and extending through the dovetail tenon from the top to the bottom. The first opening is aligned with the first hole of the block and configured to receive the first fastener, and the second opening is aligned with the second hole of the block and configured to receive the second fastener. The rotation of the first and second fasteners in their respective first and second openings causes the fasteners to pull the dovetail tenon downward toward the top platform of the block, securing the dovetail tenon to the block.

[0034] The spring cage has a base with a flat upper surface. The base is designed to fit precisely into the recess of the block's upper platform. The spring cage further features a multitude of springs that extend upwards above the flat surface of the base and exert an upward force on the underside of the dovetail tenon to secure it in position against the downward pull of the fasteners. This upward force also facilitates the release of the neck joint when required.

[0035] Finally, the dovetail slide is designed to fit precisely into the groove in the neck, reinforcing it. The dovetail slide engages with the dovetail tenon when the neck is attached to the block, facilitating movement between the neck and block. It also prevents deformation of the two surfaces due to the hardness or tempering of the materials.

[0036] It is understood that both the preceding general description and the following detailed description are exemplary but not limiting to the invention. BRIEF DESCRIPTION OF THE DRAWING

[0037] The revelation is best understood from the following detailed description when read in conjunction with the accompanying drawing. It is emphasized that the various features in the drawing are not to scale. On the contrary, the dimensions of the various features have been arbitrarily enlarged or reduced for clarity. The drawing includes the following figures: Fig. Figure 1 is a schematic perspective view of a conventional guitar; Fig. 2 is a schematic side view of the in Fig. 1 guitar shown; Fig. Figure 3 is a perspective view of the guitar neck from below, highlighting the components of the neck that are part of the linear dovetail joint; Fig. Figure 4a is a perspective rear view of the guitar block, highlighting the components of the block that are part of the linear dovetail neck joint; Fig. 4b is a perspective front view of the in Fig. 4a shown blocks; Fig. Figure 5 shows the guitar with the neck and body connected via the linear dovetail joint, and highlights the positions of a first and a second hole; Fig. Figure 6 is a perspective front view of an embodiment of the compensating sleeve, which is part of the linear dovetail neck joint; Fig. Figure 7 is a perspective front view of an embodiment of the compensating washer, which is part of the linear dovetail neck joint; Fig. Figure 8 is a perspective view of the linear dovetail neck joint, where the compensating washer is fully seated in the compensating sleeve; Fig. Figure 9 is a perspective front view of an embodiment of the dovetail tenon, which is part of the linear dovetail neck joint; In Fig. Figure 10 shows the dovetail tenon attached to the block; Fig. Figure 11 is a perspective front view of an embodiment of the spring cage, which is part of the linear dovetail neck joint; Fig. Figure 12 shows the spring cage in its position in the recess of the upper platform of the block; Fig. 13 is a perspective front view of an embodiment of the dovetail guide, which is part of the linear dovetail neck joint; and Fig. Figure 14 shows the compensating sleeve, the compensating washer, the dovetail tenon, the spring cage and the dovetail sliding piece of the linear dovetail joint in their position. DETAILED DESCRIPTION OF DISCLOSURE

[0038] An improved system for attaching the neck to the body of an instrument is provided, allowing for easy, quick, precise, and repeatable adjustment of the neck's position relative to the body, both linearly and angularly. The system also enables the user to quickly adjust the linear distance between the nut and bridge without altering the neck's angle to the body. Consequently, the user can quickly and efficiently adjust the guitar's string action, intonation, or scale length.

[0039] The stringed musical instruments according to the present invention can include guitars, such as acoustic guitars, solid-body electric guitars, and acoustic-electric guitars, but also other stringed musical instruments, such as banjos, mandolins, violins, lutes, and / or other similar instruments. Although the principles of the present disclosure are described in connection with guitars, it is to be understood that the disclosed principles are also applicable to other stringed instruments that have an instrument body and an elongated neck over which the strings are stretched.

[0040] Reference is now made to the drawing, in which the same reference symbols denote the same elements in the various illustrations of the drawing. First, the following are shown: Fig. 1 and Fig. 2 The various components of the stringed instrument according to the prior art and the present invention are briefly described. As shown in these figures, the guitar 1 has a guitar body 2 which is connected to a neck 4 in a conventional manner. The body 2 consists of a front plate 18a with a circular sound hole 28, a rear plate 18b which is opposite the front plate 18a, and a side plate 18c which is combined with the edges of the front plate 18a and the rear plate 18b such that they are spaced apart from each other. Sound resonance is generated in the interior formed by the front plate 18a, the rear plate 18b, and the side plate 18c. In addition, an opening is formed in one side of the body 2 into which the neck 4 is inserted.

[0041] The neck 4 has the shape of a beam 3 of considerable thickness with a top surface 5a and a bottom surface 5b. The neck 4 is typically made of wood or another similar or conventional material suitable for withstanding continuous string tension without warping or twisting. The neck 4 has an integrated headplate 6 that holds a number of separate tuning pegs 8 (typically six or possibly twelve), each of which in turn holds a free end of a desired string 10 in the conventional manner. The strings 10 are strung with considerable tension (e.g.,(approximately 30 pounds of tension per string) and extend from a first fixed point or axis 12, formed by a bridge 14 supported by a bridge 16 permanently attached to the front plate 18a of the guitar body 2, to a second fixed axis 20, formed by a nut 22 permanently attached to the upper surface 5a of the neck 4, located next to the headstock 6. Additionally, an adjustment rod (not shown) is fitted inside the beam 3 of the neck 4 to prevent the neck 4 from bending or deforming due to the tension of the guitar strings 10.

[0042] A fingerboard (also called fingerboard 24 on fretted instruments) is an important component of most stringed instruments. The fingerboard 24 is a thin, long strip of hard material, usually a reinforced polymer or wood such as rosewood or ebony, which fits with the top surface 5a of the neck 4 and is shaped to sit between the neck 4 and the strings 10. The material from which the fingerboard 24 is made should be strong, durable, and stable enough to support and hold the metal frets 9, which are set at regular intervals on the fingerboard 24, and to withstand the wear and tear of playing over years. The strings 10 run across the fingerboard 24 between the nut 22 and the bridge 16. On conventional guitars 1, a shoulder 26 is formed as one piece with a portion of the neck 4 and extends from the bottom surface 5b of the neck 4.

[0043] When using the guitar 1, the musician moves their fingers up and down the neck 4, pressing down on the strings 10 to shorten them and produce different pitches when the strings 10 are struck, plucked, or otherwise excited. Typically, the frets 9 on the fingerboard 24 extend across the width of the neck 4, allowing the ends of the shortened strings 10 to be anchored at specific or desired points.

[0044] In an acoustic instrument, such as an acoustic guitar 1, the body 2 encloses a resonating chamber. Striking, plucking, or otherwise exciting the strings 10 sets them into vibration. This vibration, in turn, also sets the bridge 16, over which the strings 10 extend, into vibration. In fact, the bridge 16 forms the vibrating endpoint of the strings 10 for every note played. The vibrations of the bridge 16, in turn, also set the front plate 18a of the acoustic instrument, referred to as the soundboard, into vibration. This, in turn, causes the air enclosed in the sound chamber to move, producing the sound that is heard through the soundhole 28 when the instrument is played.

[0045] Normally, the strings 10 are tuned at the top of the neck 4 or the headstock 6, where the tuning pegs 8 increase or decrease the tension on each string 10. The user then produces the desired notes by plucking the strings 10 near the center of the guitar body 2, pressing the strings 10, which extend over the neck 4, against the fingerboard 24, which is attached to the upper surface 5a of the neck 4. The sound of the produced note depends on the tension of the string 10 and the distance between the fret 9, where the string 10 is pressed against the neck 4, and the lower anchor point. The smaller the distance between the pressed string 10 and the bridge 16, the higher the resulting note. The higher the tension of the strings 10, the higher the pitch.

[0046] Fig. Figure 3 is a perspective view of the neck 4 from below, highlighting the components of the neck 4 that form part of the linear dovetail joint. A mortise or groove 30 is cut into the lower surface 5b of the neck 4, preferably, but not necessarily, having a trapezoidal cross-section and a rectangular shape. The sides of the trapezoidal cross-section of the groove 30 may be cut at an angle of approximately 28 degrees to the perpendicular. The width, length, and height of the groove 30 may be approximately 1 inch (2.5 cm), 3.35 inches (8.5 cm), and 0.55 inches (1.4 cm), respectively. These dimensions are, of course, only examples. On each side of the groove 30 is one of two slots 32, which are sized and shaped to accommodate alignment pins 34 (see Figure 3). Fig. 14). A passage 36 is provided on the upper surface 5a of the neck 4 (typically cut into the upper surface 5a).

[0047] In the Fig. Block 40 is shown, with the components of block 40 that are part of the linear dovetail neck joint highlighted. Fig. 4a is a perspective rear view and Fig. Figure 4b shows a perspective front view of block 40. Block 40 has an upper platform 42 defined by a full side wall 44a, a back wall 44c, and a partial side wall 44b. The full side wall 44a extends over the entire length of the upper platform 42; the partial side wall 44b extends only about one-third of the length of the upper platform 42. The back wall 44c connects the full side wall 44a and the partial side wall 44b. The front of block 40 is defined by a contoured surface 46 that forms part of the guitar body 2 when block 40 is attached (typically glued) to the guitar body 2. The back of block 40 is defined by a flat surface 48 that is located inside the guitar body 2 when block 40 is attached to the guitar body 2. Block 40 can consist of a single, integral part."Integral" refers to a single piece or a single, unified part that is complete without additional components; that is, the part consists of a monolithic piece formed as a single unit. Alternatively, Block 40 can also be formed by joining sections together (usually with adhesive).

[0048] Although the Block 40 can be made of plastic, it is preferably made of wood. Tests were conducted comparing the performance of a guitar 1 with a wooden Block 40 to that of a plastic Block 40. The results of these tests showed that the guitar 1 with the wooden Block 40 had a slightly higher amplitude in the fundamental tones, a slightly higher amplitude in the midrange, a slightly lower amplitude in the upper midrange, and again a higher amplitude in the treble. All results were on the order of 6 dB or less. Balance, clarity, and harmonic content were better with the wooden Block 40 than with the plastic Block 40. The guitar 1 with the plastic Block 40 delivered a flatter, dimensionless sound quality with fewer harmonics, less depth, and richer overtones. The guitar 1 with the plastic Block 40 suffered from harsh highs.The sustain was slightly longer on the guitar with the plastic block 40, but this could be due to natural differences in construction and setup.

[0049] The upper platform 42 of the block 40 has a (typically cut-out) recess 50. The recess 50 is preferably, but not necessarily, rectangular with dimensions of about 3.65 cm (1.44 in) by 2.22 cm (0.875 in) and a depth of about 2.36 cm (0.930 in). A pair of holes, namely a first hole 52a and a second hole 52b, are located next to the short sides of the recess 50 in the upper platform 42. Both the first hole 52a and the second hole 52b are preferably, but not necessarily, round and have a diameter of about 0.80 cm (0.32 in).The first hole 52a extends from the upper platform 42 to and through the underside of the block 40 and is accessible from outside the guitar 1 through a corresponding third hole 52c in the rear plate 18b of the body 2 of the guitar 1; the second hole 52b extends from the upper platform 42 to and through the contoured surface 46 of the block 40 and is directly accessible from outside the guitar 1.

[0050] Fig. Figure 5 shows the guitar 1 with the neck 4 and body 2 joined via the linear dovetail joint and highlights the positions of the first hole 52a and the second hole 52b in block 40. The second hole 52b is located closer to the neck-body joint than the first hole 52a and is recessed into the exposed portion (specifically, the contoured surface 46) of block 40, making it both visible and accessible from the outside. In contrast, the first hole 52a is not visible when the stringed instrument is fully assembled. The first hole 52a is accessible through a precisely aligned, corresponding third hole 52c in the rear plate 18b of the body 2 of the guitar 1, allowing the user to access the first hole 52a (through the third hole 52c) without having to reach into the soundhole 28 of the guitar 1.The third hole 52c can be reinforced with a protective or decorative grommet (not shown), as known to those skilled in the art. The first hole 52a and the second hole 52b are designed to receive fasteners such as threaded bolts 54a and 54b, each having a slotted head. A conventional tool (e.g., a hex key) can be used to engage the slot and turn the fasteners. Fig. Figure 5 shows that block 40 is attached to the body 2 of guitar 1 approximately in the middle of guitar body 2.

[0051] Back to the Fig. The upper platform 42 of the block 40 also has a first alignment opening 56a and a second alignment opening 56b (typically cut). Both the first alignment opening 56a and the second alignment opening 56b are preferably, but not necessarily, round and have a diameter of about 0.30 cm (0.12 in). The first alignment opening 56a and the second alignment opening 56b form blind holes in the body of the block 40 into which alignment pins 34 can be partially inserted. A portion of each alignment pin 34 protrudes from the alignment openings 56a and 56b (and beyond the upper platform 42) when the alignment pins 34 are fully inserted into the alignment openings 56a and 56b.

[0052] When inserted into the first alignment opening 56a and the second alignment opening 56b of the block 40, the alignment pins 34 assist the user in aligning the neck 4 with the block 40 when engaging the neck 4 with the block 40. Specifically, the user aligns the two slots 32 in the neck 4 with the portions of the alignment pins 34 that extend outside the alignment openings 56a and 56b, and inserts these portions into the slots 32 by pushing the neck 4 toward the block 40. The alignment pins 34 prevent unwanted lateral movement between the neck 4 and the block 40 when the linear dovetail joint is fully assembled.

[0053] Block 40 includes a shelf 58 that extends from the upper platform 42 to the flat surface 48, beneath the rear wall 44c, and partially into each of the full side wall 44a and the partial side wall 44b. The shelf 58 terminates at the flat surface 48 at a window 60 formed in the flat surface 48. The window 60 is surrounded by a notch 62. The window 60 has, for example, a substantially rectangular or oval shape with a width of approximately 5.92 cm (2.33 in) and a height of approximately 0.95 cm (0.375 in).

[0054] The flat surface 48 also has an opening 64, which serves to accommodate an intonation adjusting screw 68 (see Fig. 14). The intonation adjusting screw 68 may have a head, as in Fig. The opening 64 is shown in Figure 14, or it may be headless. The opening 64 is preferably, though not necessarily, round and has a diameter of about 0.70 cm (0.275 in). The opening 64 extends completely through the rear wall 44c from the flat surface 48 to the open area (the “neck pocket”) defined by the full side wall 44a, the rear wall 44c, the partial side wall 44b, the shelf 58, and the upper platform 42. The user can access the intonation adjustment screw 68 through the sound hole 28.

[0055] When adjusting the intonation, the length of string 10 is set by moving the neck 4 forward or backward. To shorten the overall scale length and compensate for flat intonation, the user loosens the intonation adjustment screw 68, typically using a small screwdriver. To lengthen the overall scale and compensate for sharp intonation, the user tightens the intonation adjustment screw 68. The intonation adjustment screw 68 moves the neck 4 relative to the block 40 (and thus relative to the body 2), thereby adjusting the distance between the bridge 14 and the nut 22, and thus the intonation of the guitar 1. In this way, the user can fine-tune the intonation and the overall scale length, i.e., the vibrating length of the strings 10 of the guitar 1, using the intonation adjustment screw 68 of the linear dovetail neck joint.The neck 4 is prevented by the alignment pins 34 from tilting towards the bass or treble side under string tension (i.e., lateral movement of the neck 4 is prevented), which allows adjustment along the (linear) intonation axis while maintaining a centered position relative to the bridge 16 of the guitar 1.

[0056] The flat surface 48 also has an access 66. The access 66 is formed in the top of the back panel 44c (typically cut out) and, like the opening 64, extends completely through the back panel 44c from the flat surface 48 to the neck pocket. The access 66 of block 40 is shaped to align with and engage the passage 36 in the neck 4 when the components are joined by the linear dovetail joint. Typically, the access 66 is U-shaped, with the legs separated by a distance of about 1 cm (0.385 in) and having a radius of curvature of about 0.5 cm (0.192 in). The access 66 and the passage 36 together accommodate a conventional truss rod 86 when the guitar 1 is fully assembled (see Fig. 14). The neck bar 86 is typically made of steel or titanium and has a diameter of about 4 mm (0.16 inches).

[0057] Although in Fig. 4A the opening 64 to the left of access 66 and in Fig. 4B where the opening 64 is shown to the right of the access 66, the opening 64 could also be arranged on the opposite side of the access 66. In this alternative embodiment, the opening 64 would be in Fig. 4A to the right of entrance 66 and in Fig. 4B is shown to the left of access 66. The alternative embodiments could be suitable for left-handed or right-handed musicians.

[0058] It is noteworthy that the neck 4 of the linear dovetail neck joint does not have a conventional shoulder (like the one in Fig. 2 (paragraph 26) and that the block 40 of the linear dovetail neck joint has the contoured surface 46. The absence of the step and the presence of the contoured surface 46 allow the user better access to the upper frets 9 of the guitar 1 than is possible with conventional acoustic instruments. The advantage is that the upper frets of the fingerboard 24 are extremely accessible even on an instrument with the depth of a conventional acoustic guitar (3+ inches or 7.6+ cm).

[0059] The linear dovetail neck joint comprises, in addition to the main components of the neck 4 and the block 40, a number of separable components. These separable components include a compensating sleeve 70, one or more compensating washers 90, a dovetail tenon 110, a spring cage 130, and a dovetail slide 140. The compensating sleeve 70, the one or more compensating washers 90, the dovetail tenon 110, the spring cage 130, and the dovetail slide 140 are each separate, fixed, integrated components. Each of these components is highlighted below with reference to its interaction with the neck 4, the block 40, and the other separable components.

[0060] The compensating sleeve 70 is designed so that it can be inserted into the window 60 formed in the flat surface 48 of the block 40. As in Fig. As can best be seen in Figure 6, a perspective front view of an embodiment of the compensating sleeve 70, which is part of the linear dovetail neck joint, the front face 72 of the compensating sleeve 70 is formed by a flange 74 that sits in the notch 62 of the window 60, such that the front face 72 of the compensating sleeve 70 is substantially flush with the flat surface 48 of the block 40 when the compensating sleeve 70 is fully inserted into the window 60. Like the window 60, the front face 72 of the compensating sleeve 70 also has, for example, a substantially rectangular or oval shape with dimensions similar to the window 60. Although the compensating sleeve 70 could be inserted into the window 60 by a friction fit, so that the compensating sleeve 70 could be removed from the window 60 and replaced, the compensating sleeve 70 is usually fixed (e.g., glued) in the window 60.

[0061] The compensating sleeve 70 has a top surface 76, a bottom surface 78, and a pair of side walls 80a and 80b. The top surface 76 forms a flat surface that extends only partially from the front surface 72 along the side walls 80a and 80b. In contrast, the bottom surface 78 forms a flat surface that extends completely from the front surface 72 along the side walls 80a and 80b. The bottom surface 78 has a raised rib 84 formed in the center of the bottom surface 78. Although the rib 84 could extend over the entire length of the bottom surface 78, it extends, as shown in Fig. Figure 6 shows the side walls 80a and 80b extending only along the underside 78 to the point below the top surface 76 where the top surface 76 ends. Each of the side walls 80a and 80b has a corresponding slot 82a and 82b located near the junction between the side walls 80a and 80b and the flange 74, and also a short distance behind the flange 74.

[0062] When the compensating sleeve 70 is fully inserted into the window 60 of block 40, the top 76 contacts the underside of the rear wall 44c, the bottom 78 contacts the shelf 58, and the side walls 80a and 80b contact the full side wall 44a and the partial side wall 44b of block 40, respectively. These various contact points are suitable locations for gluing the compensating sleeve 70 in its fully inserted position. In this position, the underside 78 of the compensating sleeve 70 is lower than the upper platform 42 of block 40 (i.e., it is recessed into the shelf 58 and not flush with it) to accommodate the height of the compensating washer 90.

[0063] The compensating sleeve 70 can be made of plastic and manufactured either by injection molding or additively using 3D printing (the term "additive manufacturing" can be used synonymously with 3D printing). The term "3D printing" encompasses a variety of processes in which material is assembled or solidified under computer control to create a three-dimensional ("3D") object, with material being joined together (e.g., liquid molecules or powder granules fused together), typically layer by layer. In 3D printing, a three-dimensional object is produced based on a CAD (computer-aided design) model. One of the main advantages of 3D printing is the ability to produce complex shapes or geometries. In an alternative embodiment, the compensating sleeve 70 can be manufactured from a suitable metal such as stainless steel.

[0064] Fig. Figure 7 is a perspective front view of an embodiment of the compensating washer 90, which is part of the linear dovetail neck joint. The compensating washer 90 is designed to be inserted into the compensating sleeve 70. The compensating washer 90 can be detachably inserted into and removed from the compensating sleeve 70. The geometry of the compensating washer 90 is so similar to the geometry of the compensating sleeve 70 that the compensating washer 90 engages in the compensating sleeve 70 by friction. The compensating washer 90 has a front surface 92 on which markings 91 can be depicted. The markings 91 can provide the user with a variety of information, in particular the size of the compensating washer 90. Like the compensating sleeve 70, the compensating washer 90 can also be made of plastic and manufactured either by injection molding or additively by 3D printing.

[0065] In an alternative embodiment, the compensating washer 90 can be manufactured using liquid metal technology. Liquid metals belong to a series or class of amorphous (non-crystalline) metal alloys, sometimes also referred to as metallic glasses, because the material exhibits some properties closely associated with glass. Liquid metals combine a number of desirable material properties, including high tensile strength, excellent corrosion resistance, a very high coefficient of restitution, and outstanding wear resistance, while also being thermoformable using similar processes to thermoplastics. The atomic structure of the amorphous metal results in low shrinkage (0.4%) during casting and enables the production of highly precise (± 0.0008 in or 0.02 mm), complex parts. Liquid metal is a potential replacement for many applications where plastics would typically be used.Plastics are flexible but not strong, and metals are stronger than plastics but not as flexible. Liquid metals offer an advantageous compromise: batches of amorphous steel have been produced that are three times stronger than conventional steel alloys.

[0066] The compensating washer 90 also has a stepped top surface with a higher upper section 96a and a lower upper section 96b, a bottom 98, and a pair of side walls 100a and 100b. The higher upper section 96a of the compensating washer 90 defines a flat surface that extends only partially along the side walls 100a and 100b from the front face 92 and is dimensioned and shaped to engage with the underside of the top surface 76 of the compensating sleeve 70 when the compensating washer 90 is fully inserted into the compensating sleeve 70. The lower upper section 96b of the compensating washer 90 forms a flat surface that extends from the end of the upper section 96a along the remainder of the length of the side walls 100a and 100b.The height of the lower upper section 96b determines both the size of the compensating washer 90, as reflected in the marking 91, and the distance by which the linear dovetail neck joint separates the neck 4 from the block 40 and thus from the body 2 of the guitar 1 (as will be explained further below).

[0067] The base 98 forms a flat surface extending completely from the front 92 along the side walls 100a and 100b. A track 104 is formed in the middle of the base 98 (e.g., cut). As shown in Fig. As shown in Figure 7 by dashed lines, the track 104 extends from near the front face 92 completely along the side walls 100a and 100b. Typically, the track 104 begins a short distance (e.g., about 0.065 in or 1.65 mm) behind the front face 92. The track 104 is dimensioned and shaped (with a width of, for example, about 0.1 in or 2.5 mm) to receive the rib 84 of the compensating sleeve 70 via a sliding, frictional fit. Therefore, when the user wants to insert the compensating washer 90 into the compensating sleeve 70, they align the track 104 with the rib 84 and push the compensating washer 90 forward into the compensating sleeve 70. The rib 84 slides along the track 104 as the user continues to insert the compensating washer 90.The engagement between the rib 84 of the compensating sleeve 70 and the track 104 of the compensating washer 90 ensures correct alignment and orientation when inserting the compensating washer 90 and prevents the user from inserting the compensating washer 90 into the compensating sleeve 70 in the wrong orientation (i.e., the engagement essentially makes insertion foolproof). Thus, the compensating washer 90 is compatible with the compensating sleeve 70 in one direction to ensure that the compensating washer 90 is inserted only in the correct orientation.

[0068] Each of the side walls 100a and 100b has a corresponding latch 94a and 94b located near the junction between the side walls 100a and 100b and the front face 92. Each latch has a first projection 93 located immediately behind the front face 92 and a second projection 95 located immediately in front of the front face 92. The first projection 93 and the second projection 95 each extend laterally beyond the respective side walls 100a and 100b of the compensating disc 90. The second projection 95 also projects beyond the front face 92 and can be grasped by a user when the compensating disc 90 is fully inserted into the compensating sleeve 70. The second projection 95 has multiple ribs to facilitate gripping by the user. The bars 94a and 94b are flexible and form spring-like elements in the side walls 100a and 100b.

[0069] When the user aligns the track 104 of the compensating washer 90 with the rib 84 of the compensating sleeve 70 and pushes the compensating washer 90 forward into the compensating sleeve 70, the higher upper section 96a of the compensating washer 90 slides into the top 76 of the compensating sleeve 70, the bottom 98 of the compensating washer 90 slides into the bottom 78 of the compensating sleeve 70, the side wall 100a of the compensating washer 90 slides into the side wall 80a of the compensating sleeve 70, and the side wall 100b of the compensating washer 90 slides into the side wall 80b of the compensating sleeve 70. The user pushes the compensating disc 90 further forward into the compensating sleeve 70 against the frictional force created by these interventions, until the first projections 93 touch the front 92 of the compensating sleeve 70 and are blocked by it.

[0070] At this point, the user presses the second projections 95 against each other and towards the center of the compensating disc 90, in the direction of arrows 102 and against the spring force of the latches 94a, 94b (the spring force presses the latches 94a, 94b into a position parallel to the side walls 100a, 100b). In this way, the first projections 93 can slide past the front 92 of the compensating sleeve 70 and slide a short distance along the side walls 80a, 80b of the compensating sleeve 70 until the first projections 93 reach the corresponding slots 82a, 82b of the side walls 80a, 80b. The first projections 93 then snap into the respective slots 82a, 82b of the side walls 80a, 80b, driven by the spring force against the direction of the arrows 102, so that the latches 94a, 94b return to their position parallel to the side walls 100a, 100b and the first projections 93 extend through the slots 82a, 82b and "snap" into the side walls 80a, 80b.This locking mechanism prevents the removal of the compensating washer 90 from the compensating sleeve 70 until the user wishes to remove the compensating washer 90.

[0071] The locking action produces both an audible "click" and a tactile confirmation perceptible to the user, indicating that the compensating washer 90 is fully in position and secured in the compensating sleeve 70. In this position, as in Fig. Figure 8, which is a perspective view of the linear dovetail neck joint with the compensating washer 90 fully seated in the compensating sleeve 70, shows that the front face 92 of the compensating washer 90 is substantially flush with the front face 72 of the compensating sleeve 70 and the second projections 95 of the compensating washer 90 extend a short distance beyond the front face 72 of the compensating sleeve 70; this distance is sufficient to allow the user to touch the second projections 95 when removing the compensating washer 90 from the compensating sleeve 70.To achieve removal, which may be desirable if the user wishes to replace a shim 90 with a lower upper section 96b of a first height with another shim 90 with a lower upper section 96b of a different, second height, the user again pushes the second projections 95 towards each other and towards the center of the shim 90 in the direction of arrows 102, while simultaneously pulling on the second projections 95. These actions together release the first projections 93 from the engagement in the respective slots 82a, 82b of the side walls 80a, 80b and push the shim 90 out of the shim sleeve 70.

[0072] As previously mentioned, the height of the lower upper section 96b of the shim 90 defines the distance that, through the linear dovetail neck joint, separates the end of the neck 4 from the bottom surface of the neck pocket contained in block 40, and thus defines the angle between the neck 4 and the body 2 of the guitar 1. Specifically, the leading edge of the lower surface 5b of the neck 4 rests on the lower upper section 96b of the shim 90 when the linear dovetail neck joint is fully assembled. The minimum height of the lower upper section 96b of the shim 90, which can be referred to as the "zero" height, causes the lower upper section 96b of the shim 90 to be substantially flush or uniform with the upper platform 42 of block 40 when the shim 90 is fully inserted into the shim 70 and against the upper platform 42.With a compensating disc 90 with a height of "zero", the lower surface 5b of the neck 4 therefore rests both on the lower upper section 96b of the compensating disc 90 and on the upper platform 42 of the block 40.

[0073] The lower upper section 96b of the shim 90 can, however, have any desired height, and it is intended that the user has a variety of shims 90 of different sizes on hand (perhaps he has purchased a pack of shims 90), each of which has a lower upper section 96b of a different height. Thus, the lower upper section 96b of the shim 90 can have such a height that, when the shim 90 is fully inserted into the shim sleeve 70 and rests against the upper platform 42, the lower upper section 96b projects beyond the upper platform 42 of the block 40 by a distance of zero, 0.025 in. (0.6 mm), 0.04 in. (1 mm), or any other suitable distance known to a person skilled in the art. The designation 91 for these example shims 90 could of course be “zero shim”, “0.025 inch shim” or “0.040 inch shim”.The markings 91 for these example shims 90 can also be “zero”, “0.025 in”, or “0.040 in”. For a shim 90 with a height other than the “zero” height, the lower surface 5b of the neck 4 rests only on the lower upper section 96b of the shim 90 and not on (because above) the upper platform 42 of the block 40.

[0074] When a 90mm truss rod shim with a greater height than the "zero" shim is used, the string action is brought closer to the 9th fret. This allows the playability to be tailored to the user's preferences. The interchangeable 90mm truss rod shims allow for a range of neck height adjustments depending on the player's string height (guitar string action). These shims are manufactured at different heights based on optimized string action settings, allowing for customization to the player's taste.

[0075] The shims 90 can be essentially flat or wedge-shaped to accommodate different neck angles. The linear dovetail neck joint can accept a variety of shim heights, such as three different shim heights, six different shim heights, or any other suitable number. While some conventional designs require two separate faces for shims, the linear dovetail joint uses only one face for the interchangeable shims 90.

[0076] Fig. Figure 9 is a perspective front view of an embodiment of the dovetail tenon 110, which is part of the linear dovetail neck joint. Preferably, the dovetail tenon 110 is made of metal. The embodiment of the dovetail tenon 110 has a top surface 116, a bottom surface 118, and a side 120 between the top surface 116 and the bottom surface 118. The edges between the top surface 116 and the side 120, as well as between the bottom surface 118 and the side 120, may or may not be chamfered. The dovetail tenon 110 can have any shape; for example, the one shown in Figure 9 is suitable. Fig. Figure 9 shows a substantially rectangular or oval shape (with side 120 having four radii of curvature). Suitable dimensions for the dovetail tenon 110 are a length of about 6.67 cm (2.625 in), a width of about 2.41 cm (0.95 in), and a height of about 0.90 cm (0.350 in). Preferably, the dovetail tenon 110 has a trapezoidal cross-section.

[0077] The dovetail tenon 110 has two threaded openings: a first opening 112a and a second opening 112b. The first opening 112a and the second opening 112b are aligned along the central longitudinal axis of the dovetail tenon 110 and are located at the midpoint of the width of the dovetail tenon 110, each extending completely through the height of the dovetail tenon 110 from the top 116 to the bottom 118. The first opening 112a is configured to align with the first hole 52a in the block 40 when the dovetail tenon 110 is attached to the block 40; the second opening 112b is configured to align with the second hole 52b in the block 40 when the dovetail tenon 110 is attached to the block 40. The dovetail tenon 110 is fastened to the block 40 with the threaded bolts 54a and 54b, as shown in the Fig. 10, Fig. 12 and Fig. 14 shown.

[0078] More precisely, the threaded bolt 54a is inserted through the first hole 52a in block 40 until it extends a short distance above the upper platform 42 of block 40. Similarly, the threaded bolt 54b is inserted through the second hole 52b into block 40 until it extends a short distance above the upper platform 42 of block 40. The dovetail tenon 110 is then positioned above the upper platform 42 such that the first opening 112a aligns with the first hole 52a and receives the threaded bolt 54a, while the second opening 112b aligns with the second hole 52b and receives the threaded bolt 54b.The rotation of the threaded bolts 54a, 54b in the corresponding first and second threaded openings 112a, 112b causes the threaded bolts 54a, 54b to pull the dovetail pin 110 downwards towards the upper platform 42 and secure the dovetail pin 110 to the block 40. As mentioned above, the user can use a conventional tool (e.g., an Allen key) to engage a slot in the head of each of the threaded bolts 54a, 54b and rotate the threaded bolts 54a, 54b.

[0079] Fig. Figure 11 is a perspective front view of an embodiment of the spring cage 130, which is part of the linear dovetail neck joint. The embodiment of the spring cage 130 has a substantially rectangular base 132 that defines an upper flat surface 134. A plurality of springs 136, each rigidly connected to the base 132, extend equally upward over the upper flat surface 134 of the base 132. The spring cage 130 is dimensioned and shaped (i.e., configured) to fit precisely and with friction into the recess 50 of the upper platform 42 of the block 40. Although not required, the spring cage 130 can be attached (e.g., glued) to the block 40. Fig. Figure 12 shows the spring cage 130 in the recess 50 of the upper platform 42 of the block 40.

[0080] The function of the springs 136 of the spring cage 130 is to press upwards against the underside 118 of the dovetail tenon 110 (i.e., to lift the dovetail tenon 110) when the dovetail tenon 110 is pulled downwards towards the upper platform 42 under the action of the threaded bolts 54a, 54b. This upward force also facilitates the release of the neck joint when desired. The force of the springs 136 against the underside 118 of the dovetail tenon 110 must be substantially uniform and symmetrical, so that the force is both balanced and distributed against the dovetail tenon 110, and the springs 136 must provide sufficient upward resistance to hold the dovetail tenon 110 in its position against the downward pull of the threaded bolts 54a and 54b. A single spring 136 and two springs 136 are not sufficient to meet these requirements.In contrast, the three springs 136 of the preferred embodiment of the spring cage 130 function well, with one of the three springs 136 pointing in a first longitudinal direction and the other two springs 136 pointing in the opposite longitudinal direction. The spring cage 130 can be made of plastic and additively manufactured using 3D printing. In an alternative embodiment, the spring cage 130 can be manufactured using liquid metal technology.

[0081] Fig. Figure 13 is a perspective front view of an embodiment of the dovetail slide 140, which is part of the linear dovetail neck joint. The embodiment of the dovetail slide 140 has a head 142 and two legs 144a and 144b. The dovetail slide 140 is dimensioned and shaped (i.e., configured) to fit precisely into the groove 30 in the neck 4. Therefore, the dovetail slide 140, like the groove 30, is preferably, though not necessarily, trapezoidal in cross-section and rectangular in shape. The legs 144a and 144b of the dovetail slide 140 may be formed at an angle of approximately 28 degrees to the perpendicular. The width, length, and height of the dovetail slide 140 are essentially the same as the corresponding dimensions of the groove 30. The dovetail slide 140 can be held in the groove 30 by a tight fit or fixed in the groove 30 (e.g., glued).One function of the dovetail sliding piece 140 is to reinforce the groove 30 and thereby reduce the risk of cracks in the neck 4 that could be caused by the downward pressure of the dovetail tenon 110.

[0082] Another function of the dovetail slide 140 is to facilitate movement between the neck 4 and the block 40. More precisely, the dovetail slide 140 forms a guide in the groove 30 of the neck 4. The dovetail tenon 110 engages with (i.e., slides into) the dovetail slide 140 when the user attaches the neck 4 to the block 40, as shown in Fig. 14 shown (in Fig.Figure 14 also shows the compensating sleeve 70, the compensating washer 90, and the spring cage 130 of the linear dovetail neck joint in their positions. The dovetail slide 140 minimizes friction, which could otherwise restrict the sliding movement of the dovetail tenon 110 in the groove 30. The dovetail slide 140 can be made of metal (which is preferred, especially if the dovetail tenon 110 is made of metal) or of a plastic material such as polypropylene. However, the dovetail slide 140 is made of a different material than the dovetail tenon 110 (even if both are made of metal) to prevent galling of the two mating surfaces. The dovetail slide 140 could be lubricated to facilitate the movement of the neck 4 in the block 40.However, with a self-gliding material such as metal or polypropylene, lubrication is unnecessary to create a surface that is optimal for the movement of the neck 4 relative to the block 40.

[0083] When the dovetail tenon 110 is inserted into the dovetail slide 140 (and thus into the groove 30 of the neck 4), the user can tighten the bolts 54a and 54b from outside the guitar 1, thereby pulling the dovetail tenon 110 downwards against the upward force of the spring cage 130 towards the block 40. This simultaneously pulls the neck 4 downwards into engagement with the block 40 and the body 2 of the guitar 1. The user continues to tighten the bolts 54a and 54b until the neck 4 is firmly and securely pulled into the block 40. The neck 4 engages with the alignment pins 34 as it is tightened. Conversely (i.e., when the bolts 54a and 54b are loosened), the neck 4 separates from the body 2 and can eventually be removed from the body 2. The upward force of the spring cage 130 facilitates such separation and removal.

[0084] The linear dovetail neck joint allows the user to adjust the height between the neck 4 and the body 2, the angle between these instrument components, or both. The two bolts 54a and 54b, which engage in the dovetail tenon 110, might suggest that adjusting one of the bolts (e.g., bolt 54a) by a different amount than the other bolt (e.g., bolt 54b) could affect the angle. However, the user must tighten both bolts 54a and 54b to the same torque to ensure the neck 4 and body 2 connect correctly.

[0085] The linear dovetail neck joint serves to attach the neck 4 to the body 2 of the guitar 1 by means of an internal dovetail, the tension of which can be adjusted by screws. There are no bolts or permanent adhesives that directly connect the neck 4 to the body 2. There are also no fasteners or threaded inserts that are directly inserted or screwed into the neck 4. The neck 4 is connected to the body 2 by an indirect connection, while the linear dovetail joint applies a consistent, adjustable, downward tension to the neck 4. With the linear dovetail joint, the neck 4 does not need to be removed from block 40 to adjust its position relative to the body 2 of the guitar 1. However, the neck 4 can be removed from the body 2 using the linear dovetail joint, allowing the user to adjust or replace the neck 4.The linear dovetail neck joint allows the user to easily replace the necks of the guitar.

[0086] Furthermore, with conventional designs, the neck 4 must be completely removed from the body 2 to access the shims for neck adjustment. With the linear dovetail neck joint, the shims 90 can be easily replaced by loosening the linear dovetail neck joint and clicking in a different shim 90 as desired. This is much more convenient for both manufacturers and end users. In production, this feature allows for a uniform size of bridge 16 and saddle 14 for stringed instruments, in contrast to the conventional combination of several (e.g., three) different bridges and many (e.g., five) different saddle heights to achieve the correct geometry. Now, the correct geometry at the neck joint can be reliably achieved by using the shims 90 without the need for repeated disassembly.

[0087] The linear dovetail neck joint allows for exceptional accessibility to the frets in the upper register of the fingerboard, easier neck adjustments, intonation corrections, and unique front block configurations with hand relief, all without the need for adhesives. It enables a practical and aesthetically pleasing neck-body joint without the need for a shoulder on the neck. The result is a neck-body joint that is easy to play, adjust, and maintain.

[0088] Although illustrated and described above with reference to certain specific embodiments and examples, the present invention is not intended to be limited to the details shown. Rather, various modifications to the details may be made within the scope and the scope of the equivalents of the claims without departing from the spirit of the invention. For example, it is expressly intended that all areas mentioned in this document in a broader sense include all narrower areas that fall within the broader areas.

Claims

[1] Linear dovetail neck joint for a musical instrument (1) with a body (2), wherein the linear dovetail neck joint has the following: a neck (4) with a lower surface (5b) with a groove (30); a block (40) with a contoured surface (46) which forms part of the body (2) when the block (40) is attached to the body (2), an upper platform (42) with a hole (52a, 52b) accessible from outside the musical instrument (1) and configured to receive a fastening element (54a, 54b), and a rear surface (48) with a window (60); a compensating sleeve (70) designed to be inserted into the window (60) of the block (40); at least one substantially flat or angled compensating washer (90) configured to fit into the compensating sleeve (70), the compensating washer (90) having an upper section (96a, 96b) with a height defining the distance by which the linear dovetail neck joint separates the neck (4) from the block (40) when the lower face (5b) of the neck (4) rests on the upper section (96a, 96b) when the linear dovetail neck joint is fully assembled; and a dovetail tenon (110) which engages at least indirectly in the groove (30) of the neck (4) and has a top (116), a bottom (118) and an opening (112a, 112b) extending through the dovetail tenon (110) from the top (116) to the bottom (118), wherein the opening (112a, 112b) is aligned with the hole (52a, 52b) of the block (40) and is configured to receive the fastener (54a, 54b), and wherein a rotation of the fastener (54a, 54b) in the opening (112a, 112b) causes the fastener (54a, 54b) to pull the dovetail tenon (110) together with the neck (4) downwards towards the upper platform (42) of the block (40) and the dovetail tenon (110) and neck (4) attached to the block (40). [2] Linear dovetail neck joint according to claim 1, wherein the linear dovetail neck joint does not have any screws that engage directly into the neck (4) or a shoulder (26) on the neck (4). [3] Linear dovetail neck joint according to claim 1 or 2, wherein the upper platform (42) of the block (40) has a recess (50) and the linear dovetail neck joint further comprises a spring cage (130) with a base (132) having an upper flat surface, wherein the base (132) is configured to fit precisely into the recess (50) of the upper platform (42) of the block (40), and a plurality of springs (136) extending upwards over the flat surface of the base (132) and exerting an upward force on the underside (118) of the dovetail tenon (110) to fix the dovetail tenon (110) in its position against the downward pull of the fastening element (54a, 54b). [4] Linear dovetail neck joint according to any of the preceding claims, further comprising a dovetail slide (140) configured to fit precisely into and reinforce the groove (30) in the neck (4), wherein the dovetail slide (140) engages with the dovetail tenon when the neck (4) is attached to the block (40) and facilitates movement between the neck (4) and the block (40). [5] Linear dovetail neck joint according to one of the preceding claims, wherein the rear surface (48) of the block (40) has an opening (64) and the linear dovetail neck joint further comprises an intonation adjusting screw (68) which is received in the opening (64) to move the neck (4) relative to the body (2) and to adjust the intonation of the musical instrument (1). [6] Linear dovetail neck joint according to any one of the preceding claims, wherein the lower surface (5b) of the neck (4) has at least two slots (32) and the upper platform (42) of the block (40) has at least two alignment openings (56a, 56b), wherein an alignment opening (56a, 56b) is aligned with and corresponds to each of the at least two slots (32) in the lower surface (5b) of the neck (4) when the linear dovetail neck joint is fully assembled, and the linear dovetail neck joint further comprises at least two alignment pins (34), wherein an alignment pin (34) is partially inserted into each of the at least two alignment openings (56a, 56b) in the upper platform (42) of the block (40) and into the aligned and corresponding slots (32) in the lower surface (5b) of the neck (4) when the linear dovetail neck joint is fully assembled The dovetail neck joint is fully assembled.wherein the alignment pins (34) align the neck (4) with the block (40) and prevent movement of the neck (4) from side to side. [7] Linear dovetail neck joint according to one of the preceding claims, wherein the neck (4) has an upper surface (5a) with a passage (36) configured to receive a neck rod (86), and the block (40) has an access (66) aligned with the passage (36) in the upper surface (5a) of the neck (4) and configured to receive the neck rod (86). [8] Linear dovetail neck joint according to one of the preceding claims, wherein the body (2) has a third hole (52c), the block (40) has a bottom surface and the upper platform (42) of the block (40) has a second hole (52b) extending from the upper platform (42) through the bottom surface, aligned with the third hole (52c) in the body (2), accessible from outside the musical instrument (1) and configured to receive a second fastening element (54b). [9] Linear dovetail neck joint according to claim 8, wherein the dovetail tenon (110) has a second opening (112b) extending downwards through the dovetail tenon (110) and a central longitudinal axis along which the opening (112a) and the second opening (112b) are respectively aligned, wherein the second opening (112b) is aligned with the second hole (52b) of the block (40) and is configured to receive the second fastening element (54b), and wherein the rotation of the second fastening element (54b) in the corresponding second opening (112b) causes the second fastening element (54b) to pull the dovetail tenon (110) downwards towards the upper platform (42) of the block (40) and fastens the dovetail tenon (110) to the block (40). [10] Linear dovetail neck joint according to one of the preceding claims, wherein the compensating sleeve (70) has a front (72), a bottom (78) with a raised rib (84) and side walls (80a, 80b) each with a slot (82a, 82b). [11] Linear dovetail neck joint according to claim 10, wherein the at least one substantially flat or angled compensating washer (90) is configured to engage with the compensating sleeve (70) in a close friction fit, the compensating washer (90) having a base (98) with a track (104) configured to receive the rib (84) of the compensating sleeve (70), and side walls (100a, 100b) each having a corresponding flexible and spring-like latch (94a, 94b) having a first projection (93) configured to snap into the corresponding slots (82a, 82b) of the side walls (100a, 100b) of the compensating sleeve (70) when the compensating washer (90) is fully seated in the compensating sleeve (70), and a second projection (95) which extends extends a short distance beyond the front (72) of the compensating sleeve (70),when the compensating washer (90) is fully seated in the compensating sleeve (70). [12] Linear dovetail neck joint according to one of the preceding claims, wherein the musical instrument (1) has a saddle (22), a bridge (14) and a linear distance between the saddle (22) and the bridge (14) and the linear dovetail neck joint is configured to set the linear distance between the saddle (22) and the bridge (14) without any change to the angle of the neck (4) relative to the body (2). [13] Linear dovetail neck joint according to one of the preceding claims, wherein the block (40) is made of wood. [14] Linear dovetail neck joint according to one of the preceding claims, further comprising several compensating washers (90) of different sizes. [15] Linear dovetail neck joint according to claim 14, wherein each of the multiple compensating washers (90) has a marking (91) indicating the size of the compensating washer (90). [16] Musical instrument (1) with the linear dovetail neck joint according to one of the preceding claims. [17] Musical instrument (1) according to claim 16, wherein the musical instrument (1) is a guitar. [18] Linear dovetail neck joint for a musical instrument (1) with a body (2) having a back plate (18b) with a third hole (52c), wherein the linear dovetail neck joint has the following: a neck (4) with an upper surface (5a) having a passage (36) for receiving a neck rod (86) and a lower surface (5b) with a groove (30) and at least two slots (32); an intonation adjustment screw (68) for moving the neck (4) relative to the body (2) and for adjusting the intonation of the musical instrument (1); a block (40) comprising (i) a contoured surface (46) that forms part of the body (2) when the block (40) is attached to the body, (ii) a bottom, (iii) an upper platform (42) comprising a recess (50), a first hole (52a) extending from the upper platform (42) through the bottom and aligned with the third hole (52c) in the rear plate (18b) of the body (2) and accessible from outside the musical instrument (1) and configured to accommodate a first fastening element (54a), a second hole (52b) extending from the upper platform (42) through the contoured surface (46) and accessible from outside the musical instrument (1) and configured to accommodate a second fastening element (54b), and at least two alignment openings (56a, 56b), wherein one alignment opening (56a,56b) is aligned with and corresponds to each of the at least two slots (32) in the lower surface (5b) of the neck (4) when the linear dovetail neck joint is fully assembled, and (iv) a rear surface (48) with a window (60), an opening (64) configured to receive the intonation adjusting screw (68), and an access (66) aligned with and configured to receive the passage (36) in the upper surface (5a) of the neck (4); at least two alignment pins (34), wherein one alignment pin (34) is partially inserted into each of the at least two alignment openings (56a, 56b) in the upper platform (42) of the block (40) and into the aligned and corresponding of the at least two slots (32) in the lower surface of the neck (4) when the linear dovetail neck joint is fully assembled, wherein the alignment pins (34) align the neck (4) with the block (40) and prevent side-to-side movement of the neck (4); a compensating sleeve (70) configured to fit into the window (60) in the block (40), the compensating sleeve (70) having a front (72), a bottom (78) with a raised rib (84) and side walls (80a, 80b) each with a slot (82a, 82b); at least one substantially flat or angled compensating washer (90) configured to be inserted into the compensating sleeve (70) and engaging with the compensating sleeve (70) in a close friction fit, the compensating washer (90) having an upper section (96a, 96b) with a height defining the distance by which the linear dovetail neck joint separates the neck (4) from the body (2) when the lower surface (5b) of the neck (4) rests on the upper section (96a, 96b) when the linear dovetail neck joint is fully assembled, a bottom (98) with a track (104) configured to receive the rib (84) of the compensating sleeve (70), and side walls, each with a corresponding flexible and spring-like latch, which has a first projection (93) configured to engage in the corresponding slots (82a, 82b) of the side walls (80a,80b) the compensating sleeve (70) snaps into place when the compensating washer (90) is fully seated in the compensating sleeve (70), and has a second projection (95) that extends a short distance beyond the front face (72) of the compensating sleeve (70) when the compensating washer (90) is fully seated in the compensating sleeve (70);, a dovetail tenon (110) with a top (116), a bottom (118) and a central longitudinal axis with a first opening (112a) and a second opening (112b) each aligned along the axis and extending through the dovetail tenon (110) from the top (116) to the bottom (118), wherein the first opening (112a) is aligned with the first hole (52a) of the block (40) and is configured to receive the first fastener (54a), and the second opening (112b) is aligned with the second hole (52b) of the block (40) and is configured to receive the second fastener (54b), and wherein the rotation of the first and second fastener in the corresponding first and second openings (112a, 112b) causesthat the fastening elements pull the dovetail tenon (110) downwards towards the upper platform (42) of the block (40) and fasten the dovetail tenon (110) to the block (40); a spring cage (130) with a base (132) having an upper flat surface, the base (132) being configured to fit precisely into the recess (50) of the upper platform (42) of the block (40), and a plurality of springs (136) extending upwards over the flat surface of the base (132) and exerting an upward force against the underside (118) of the dovetail tenon (110) to fix the dovetail tenon (110) in its position against the downward pull of the fasteners (54a, 54b); and a dovetail slide (140) configured to fit precisely into and reinforce the recess (50) in the neck (4), the dovetail slide (140) engaging in the dovetail tenon (110) when the neck (4) is attached to the block (40), and facilitating movement between the neck (4) and the block (40). [19] Musical instrument (1) with the linear dovetail neck joint according to claim 18. [20] Musical instrument (1) according to claim 19, wherein the musical instrument (1) is a guitar.

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