US 2236946 A
Description (OCR text may contain errors)
April l, 1941. .1, w. KNOPP STRINGED MUSICAL INSTRUMENT Filed May 16, 1958 @wwwa/.30,
Patented Apr. 1, 1941 QFCE STRINGED MUSICAL INSTRUMENT Julius W. Knopp, Toledo, Ohio, assignor to La Verne Pettegrew, Cleveland, Ohio Application May 16, 1938, Serial No. 208,149
This invention relates to musical instruments of the string type., and has for its object the provision of certain improvements therein whereby to enhance the playing qualities and commercial practicabilities thereof and also the electrical reproduction or amplication of sound therefrom.
Further objects and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawing, in which- Figure l is a side view of an instrument embodyingthe invention, with parts broken away; Fig. 2 is a fragmentary top plan view thereof; Fig. 3 is an enlarged cross-section on the line 3--3 in Fig. 2, and Fig. 4 is an enlarged fragmentary section on the line 5 4 in Fig. 2, with a portion broken away.
Referring to the drawing, I designates the body of an instrument embodying the invention, 2 the neck projecting transversely from the body, and 3 the metal instrument strings, in the present instance five in number. These strings eX- tend over the customary front and rear bridges 4 and 5, respectively, and are attached at their forward ends to the usual keys 6, carried by the head portion of the neck, and at their rear ends to respective tail-pins l., carried by a tailplate 8.
The body I is hollow and preferably of cylindrical form. with its axis transverse to the major axis cf the neck 2, and is provided on its top. preferably centrally thereof, with a shallow wall 9. in the present instance of cylindrical form, which forms a chamber I above the body. The tail-plate 8 is mounted on the top of the wall 9, being attached thereto by screws II, or in any other suitable manner, and closes the top of said chamber.
Secured to the under side of the tail-plate 8 within the chamber Il) is a wear plate I 2 of metal, or other suitable material, having a row of sleeves I3 projecting outward therefrom through the plate 8 and also having a row of fulcrum openings I4 therein in register with respective openings I5 in the plate 8. 'Ihe rou1 of sleeves I3 is crosswise to the maior axis of the neck 2, as is also the row of openings I4, and they correspond in number to the strings 3 and substantially register with the rear ends of the strings. The plate I2 and the sleeves I3 are secured to the tail-plate 8 by nuts threaded on the outer ends of the respective sleeves.
A tail-pin 'I is provided for and extends through each fulcrum opening I4 and its registering openforward end thereof.
ing I5 and has a swivel or fulorum mount in the respective opening I 4. Each pin I is of L-form with its lower angled end portion 'la extending rearwardly within the chamber I0 and under a respective sleeve I3. An adjusting screw I'I is threaded down through each sleeve I3 and has downward thrust engagement with the registering pin portion la. It is apparent that an adjustment of a screw II effects an adjustment of the Ipin 'I and attached string 3. This adjustment permits a ne tuning adjustment of each string after a preliminary tuning adjustment thereof by an associated key 6.
An electrical sound take-off plate 2i! is mounted on the inner end portion of the neck 2 immediately in advance of the bridge 5 and is set into the top or finger board portion of the neck with its top surface flush with that of said board. This plate constitutes a permanent magnet and forms a core for the coil 2l wound around the Flux from the magnet links the metal strings 3 and vibration of the strings in the magnetic field thus set up causes small currents to flow in the strings, which currents induce a current in the coil 2l. The ends of such coil are connected to separate contacts in a jack-receiving socket 22 in the bottom of the body i. The socket 22 is adapted to receive a jack, not shown, in circuit with an amplifier so that current flowing in the coil may be amplied to produce audible sounds, the frequency of which is determined by the frequency of vibration of the strings 3.
The magnet plate and the finger board portion of the neck Z are preferably of arcuate form in cross-section and the several strings 3 are arranged in similar arcuate form so as to space them equidistantly from such parts. It is found that better results are obtained by making the magnet plate in this form. Such plate, in the present instance, covers a socket 23 in the neck 2, which socket communicates with the interior of the body I and through which the terminals of the coil 2| are extended to the respective contact portions of the socket 22.
25 designates the usual chin piece secured to the top portion of the body I at its rear end, and 26 is a tongue of thin material attached to the rear end portion of the body and disposed substantially parallel to its rear side edge for engagement over and at the rear of a collar worn by the player of the instrument when the instrument is in playing position. This collar engaging tongue facilitates holding the instrument in playing position.
I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.
Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:
l. In a stringed musical instrument having a body, a neck projecting therefrom and metal strings extending lengthwise of the neck and bridged therefrom, a magnet plate mounted on the top finger board portion of the neck below the strings with its top surface in equidistantly spaced relation to all of the strings so that the eld of the magnet links all of said strings, and an electrical coil about a portion of said plate as a core and adapted to be placed in circuit with an amplifying instrument.
2. In a stringed musical instrument having a body, a neck projecting therefrom and metal strings extending lengthwise of the neck and bridged therefrom, a magnet plate mounted on the top n'ger board portion of the neck below the strings with its top surface in equidistantly spaced relation to all of the strings so that the eld vof the magnet links all of said strings, and said magnet plate being of arcuate form in crosssection transversely of the strings, and an electrical coil about a portion of said plate as a core and adapted to be placed in circuit with an amplifying instrument.
3. In a stringed musical instrument having a body, a neck projecting therefrom with its finger board surface of convex arcuate form in crosssection, and metal strings extending lengthwise of the neck and bridged from the ringer board surface thereof and spaced transversely of said neck, a magnet plate mounted on the top nger board portion of the neck below the strings with its top surface flush with the finger board surface of the neck and of corresponding arcuate form and spaced equidistantly from the strings so that the eld of the magnet links all of said strings, and an electrical coil about a portion of said plate as a core and adapted to be placed in circuit with an amplifying instrument.
4. In a stringed musical instrument, a hollow circular body, a neck projecting therefrom, metal strings extending lengthwise of the neck and bridged from the top surface thereof, a magnet plate mounted on the top finger board portion of the neck below the strings with its top surface in equidistantly spaced relation to all of the strings so that the field of the magnet links all of said strings, a coupling jack socket disposed in the bottom of the body substantially centrally thereof and having spaced Contact portions, and an electrical coil encircling a portion of said magnet plate as a core and having its terminals extended to and connected to respective contact portions of said socket.
JULIUS W. KNOPP.