Combined bridge and string anchoring device for stringed musical instruments

#The present invention relates to stringed musical instruments, especially stringed musical instruments having fretted necks such as Guitars, Basses and Mandolins. Stringed musical instruments are equipped with "bridges" i.e. support structures on the body of the instruments that lift strings tensioned between an anchoring device on the body of the instrument and the tuning keys in the head of the instrument above the surface of the body and the neck of the instrument, and by contact of their support ledges with the strings they determine the effective length and hence the fundamental frequency of the active sound-producing portion of the strings. Strings differ in quality, even those intended to produce the same notes, and portions of the very same string may differ in quality, for instance may be of non-uniform thickness longitudinally thereof. Also there may be gross irregularities in the construction of the body of the instrument. It is therefore frequently desirable to provide special adjustments beyond and in addition to the tuning keys in the neck of the instrument to obtain proper performance. For instance, it may be desirable to adjust the total effective length and tension of all or some of the strings individually and to raise or lower them as a whole relative to the upper surface of the neck and body of the instrument; and it may even be necessary to tilt the string supporting bridge ledge both about a vertical or a horizontal axis.

#It is an object of my invention to provide a bridge structure for attachment to the body of stringed musical instruments, that provides all these adjustment possibilities.

#More particularly it is an object of the present invention to provide a bridge structure of the type referred to, that permits individual adjustment of the individual strings and also adjustment of the strings as a whole, i.e. where all of them may be raised or lowered relative to the top surface of the body and neck of the instrument, and may be tilted if desired.

#The invention will best be understood by reference to the accompanying drawing which illustrates a preferred embodiment and wherein

#FIG. 1 is a plan view of a guitar equipped with a combined bridge and string-anchoring device embodying my invention;

#FIG. 2 is a perspective of the device of my invention;

#Referring first to FIG. 1, the reference numeral 10 designates the body of the guitar, which has a neck 12 with frets 14, and a head 16 with the conventional keys 18 for tuning the strings 20. The strings pass over a pick-up 22 of conventional design mounted upon the body of the instrument and are anchored in the device of my invention which is collectively identified by the reference numeral 24 and is adjustably held upon the body of the instrument. This device has roughly the shape of a bar (FIG. 2) that is disposed transversely of the body of the guitar. On its opposite ends it is provided with hook-shaped extensions 28a and 28b that point in a direction forwardly of the instrument i.e. toward the head 16 (FIG. 1), and which define two deep recesses 30a and 30b, respectively, (FIG. 2) which are open in a direction forwardly of the instrument to be engaged over and receive bolts 32 that are securely anchored in body of the instrument (FIG. 6).

#The bolts 32 are of such construction that they may be manipulated to raise or lower the device of the invention relative to the body of the instrument. Having reference to FIG. 6, the bolts 32 have internally threaded base bushings 34 that are firmly secured to the body of the instrument and which may have fluted outer surfaces as shown at 35, to resist rotation relative to the instrument body; and threadably engaged in said bushings are the screw bolts proper 36 which rise above the bushings and are provided with a slotted screw head 38 of conventional design. Below the heads the bolts carry firmly secured thereto disks 40 with smooth upper surfaces. The distance between the bottom surfaces of the screw heads and the top surfaces of the discs is such that they will smoothly receive the vertical thickness of the hooks 28 on the opposite ends of the device of my invention. By turning the screws 36 they may be made to rise higher or descend deeper into the bushings 34 and thus the device of my invention as a whole or one or the other end thereof may be raised higher above, or brought closer to, the upper surface of the body of the instrument, as the case may be.

#The bight portions of the hooks 28a and 28b on the opposite ends of the device of the invention are provided with threaded apertures 42a and 42b extending longitudinally of the instrument which are engaged by screw bolts 44a and 44b respectively (FIGS. 2, 3 and 6). The outer ends of these screw bolts are provided with drive slots and their inner ends bear against the stem portions 36 of the screws 32 of the described bridge-raising and lowering mechanism. Thus, when the bridge assembly of my invention is installed in place upon the body of the instrument, its position relative to the body of the instrument longitudinally thereof may adjusted by turning the screws 44a and 44b, and it may even by imparted a slightly tilted or oblique position, if desired, by turning one or the other of these screws.