Stringed musical instrument

A stringed musical instrument of a resonator guitar type, including an elongated, substantially horizontal, hollow body supporting pegs, a fret board, and a resonator in which each of the string members includes an elongated string, an elongated rigid string bar and a string cable, connected end-to-end. The strings extend over and lightly engage a transverse bridge, while the rigid string bars bear against a transverse support rod adjacent the bridge. The cables are connected to tuning lever members independently pivotally mounted upon a transverse tuning shaft at the tail end of the body. Operative members, such as pedals and/or knee levers are connected by linkages to the tuning lever members for controlling the tension in the strings.

BACKGROUND OF THE INVENTION 
This invention relates to a table-mounted, substantially horizontal, 
stringed musical instrument, and more particularly to a resonator guitar 
in which the tuning structure for the strings has been improved. 
Stringed musical instruments mounted substantially horizontal upon tables 
and having elongated strings mounted for operative tuning by pedals or 
knee levers, are well known in the art. One such stringed musical 
instrument is the pedal steel guitar, in which pedals and knee levers are 
connected mechanically to the strings to change the tension in the strings 
and therefore the tone of the instrument. The pedal steel guitar is an 
electrical guitar, provided with an electrical pick-up and an amplifier, 
as opposed to an acoustical guitar incorporating a resonator. 
In the above pedal steel guitars, the strings extend the full length of the 
body of the instrument and are bent sharply about the bridge of the 
instrument. Thus, the movement of the strings by vibration from playing, 
and by tuning adjustments, create chafing between the strings and the 
bridge, ultimately resulting in string breakage. 
Another stringed musical instrument, known in the trade as a "Do-Bro", is 
an acoustical guitar with a resonator in the body of the guitar protected 
by a perforated cover. The instrument is held by the performer against his 
body or on his lap and played with picks and bars as a conventional 
acoustical guitar. The "Do-Bro" does not utilize pedals or knee levers to 
activate the strings, which are fixed upon the instrument. 
SUMMARY OF THE INVENTION 
It is therefore an object of this invention to provide a stringed musical 
instrument, of a table-top resonator guitar type, in which the string and 
string support structure have been altered in order to improve their wear 
resistance and the tonal quality of the instrument. 
A stringed musical instrument made in accordance with this invention 
includes an elongated hollow sound box or body supporting on its top 
surface a head in which are mounted the conventional tuning or string 
pegs, an elongated fret board, and a resonator supporting a transverse 
bridge. Each of the string members includes in series an elongated 
flexible string, an elongated rigid string bar, and a string cable, 
connected end-to-end. The strings are extended from the pegs across the 
bridge and connected to one end of the respective string bars. The string 
bars are supported in substantial alignment with the strings and bear 
against an elongated transverse support bar adjacent the bridge. Thus, 
most of the pressure exerted by the string members upon the instrument 
body is transmitted by the string bars to the transverse support rod and 
not to the bridge. The cables attached to the other ends of the string 
bars are connected to, and partially wrapped about, a plurality of tuning 
levers, independently and pivotaly movable about a transverse tuning 
shaft. The tuning levers are then connected to an actuator mechanism 
including a plurality of link rods connected through various linkages to 
pedals and knee levers for independently varying the tension in the string 
members. 
In a preferred form of the invention, the hollow body has a substantially 
horizontal flat top surface with the portion of the top surface supporting 
the resonator tapering downward toward the end of the body supporting the 
transverse tuning shaft. The sloping of the top surface is not only for 
appearance, but primarily to shorten the length of the string members. 
The utilization of the rigid string bars bearing against the transverse 
support rod minimizes the wear in the strings, as well as reduces the 
pressure of the strings against the bridge and the resonator to provide an 
improved quality of musical tones and longer-lasting strings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings in more detail, FIGS. 1, 2 and 3 disclose a 
stringed musical instrument 10 of the guitar resonator type, made in 
accordance with this invention, including an elongated substantially 
rectangular table member 11 supported at its corners by the four legs 12. 
Fixed on top of the table member 11 is an elongated, hollow body 14 having 
a top surface 15. 
As viewed in FIGS. 1 and 3, mounted on the top surface 15 of the hollow 
body 14 at the left end portion as viewed in FIGS. 1 and 3, is a head or 
headpiece carrying a plurality of tuning pegs 17. At the right or tail end 
portion of the hollow body 14 is a large opening or hole 18 in a resonator 
frame 19 receiving a dish-shaped resonator 20 of conventional 
construction. Extending between the resonator frame 19 and the head 16 is 
an elongated fret board 21. The resonator 20 is provided with a supporting 
spider frame 23 including a transverse bridge support bar 24. 
A disc-shaped resonator cover 25 spans the hole 18 and covers the resonator 
20. The cover member 25 has a rim 26 which is secured and supported by the 
perimeter of the resonator frame 19 surrounding the hole 18. No part of 
the cover member 25 is supported by any portion of the resonator 20. The 
resonator cover 25 includes a plurality of perforations 27 and an 
elongated slot 28 directly above the bridge support bar 24. Secured to the 
bridge support bar 24 is an upstanding transverse bridge bar 29 supporting 
a plurality of transversely spaced, vertical, bridge rollers or wheels 30 
supported for independent rotary movement upon a transverse shaft or axle 
31. 
A tuning shaft 32 is fixed to a pair of transversely spaced stanchions or 
standards 33 upon the tail end portion of the table member 11 adjacent the 
tail end of the hollow body 14. The tuning shaft 32 is substantially 
parallel to the bridge bar 29, and about the same length as the bridge bar 
29. 
Rotatably supported upon the tuning shaft 32 are a plurality of tuning 
lever members 34, (FIGS. 6, 8 and 10). Each tuning lever member 34 
includes a tuning arm 35 journaled upon and depending from the tuning 
shaft 32. The tuning lever member 34 also includes an elongated first 
toggle member or arm 36 also journaled to the tuning shaft 32 and 
depending closely adjacent the tuning arm 35. The rear edge of the lower 
portion of the toggle member 36 includes a transverse connector flange 37 
having a plurality of apertures, each of which is adapted to receive an 
elongated connecting rod or wire 59. The lever member 34 further includes 
a second toggle member 38 which is pivotally connected to the first toggle 
member 36 by a pivot pin 39 above the connector flange 37. The lower rear 
edge portion of the second toggle member or arm 38 is also provided with a 
transverse connector flange 40 below the connector flange 37. The upper 
end of the second toggle member 38 is provided with an upper projection or 
latch tongue 41 adapted to engage a latch abutment member 42 projecting 
downward from the tuning arm 35. The second connector flange 40 is also 
provided with plurality of holes or apertures for receiving elongated 
connecting rods or wires 60. 
Extending longitudinally over the fret board 21, the resonator 20, and the 
tuning shaft 32 are a plurality of elongated string members 45. Each 
string member 45 includes an elongated musical string 46 of conventional 
construction and material for conventional stringed musical instruments. 
However, the strings 46 do not extend the full length of the instrument 10 
and are relatively shorter than are conventionally required for a 
conventional stringed musical instrument, such as an electric guitar. As 
disclosed in the drawings, and particularly FIGS. 1 and 3, the strings 46 
extend from the head 16 over the bridge bar 29 and engaging the 
corresponding bridge rollers 30, to a position slightly rearward of the 
bridge bar 29. The head ends of the strings 46 are connected to 
corresponding individual pegs 17 in a manner conventional for stringed 
musical instruments. 
However, each string member 45 , in addition to the musical string 46, 
includes an elongated rigid string bar 47 and a string cable 48. 
The tail end of the string 46 is looped around a tiny spool-like connector 
piece 49 and then wrapped upon itself to form the coil winding 50 to 
secure the string 46 to the connector piece 49. The connector piece 49 is 
then inserted into a key-way slot 51 in the head end of the rigid string 
bar 47, as best disclosed in FIGS. 8 and 9. The connector piece 49 may be 
retained in place by a bearing plate 52 secured to the bottom of the 
string bar 47 by a screw 53. 
The bottom surface of each of the bearing plates 52 is adapted to rest upon 
a transverse support rod 54 transversely fixed to the resonator cover 25. 
Each bearing plate 52 may be moved toward and away from the string bar 47 
by an adjustment set screw 55 in order to vary the elevation of the string 
bar 47 relative to the support rod 54. The bearing plate 52 is permitted 
to move relative to the string bar 47 because of the play or loose 
connection between the screw 53 and the bearing plate 52, or because of 
the elastic material from which the bearing plates 52 may be made. 
The head ends of the string cables 48 are inserted into corresponding 
openings in the tail ends of the string bars 47 and secured in fixed 
position by the set screws or clamp screws 57. Each of the flexible string 
cables 48 extends around and in engagement with the rounded surface of 
each of the tuning arms 35, as illustrated in FIGS. 6 and 8. The tail ends 
of the string cables 48 extend to corresponding openings in the rear 
surface of each of the tuning arms 35 and is secured therein by 
corresponding clamp screws 58. 
As best disclosed in FIGS. 6 and 8, the transverse support rod 54 is fixed 
at an elevation relative to the bridge bar 29 and the tuning shaft 32 
which will permit each of the musical strings 46 and its corresponding 
string bar 47 to extend in substantially a straight line. Each of the 
stringed bars 47 is not only rigid but of substantially greater 
cross-sectional area than its corresponding string 46. Thus, the pressure 
exerted by any of the string members 45 against the hollow body 14 or 
cover 25 will be borne subtantially entirely by the transverse rod 54 and 
the tuning shaft 32. Because the transverse support rod 54 is fixed to the 
cover 25 and the cover 25 is solidly supported by the perimeter of the 
resonator frame 19, instead of the resonator 20, substantially little 
pressure is exerted by any of the strings members 45 against the resonator 
20. Any sound conducted from the vibrating string 28 will be conducted 
through the corresponding bridge roller 30, bridge bar 29, bridge support 
bar 24 to the resonator 20, in order to improve the tonal quality of the 
instrument 10. 
Each of the tuning levers 34 is designed to rotate the tuning arm 35 in 
either rotary direction about the tuning shaft 32 in order to either raise 
or lower the tone of its corresponding string member 45. The direction of 
rotation of the tuning arm 35 is dependent upon which of the connector 
flanges 37 or 40 is pulled to the left in FIGS. 6 and 8 by its 
corresponding elongated connecting rod 59 or 60. The connecting rods 59 
and 60 form a part of a linkage assembly 62 which is used in conventional 
pedal steel guitars and are ultimately controlled by corresponding pedals 
63 and knee levers 64 and 65. 
One of the rods 60, as disclosed in FIG. 6 is connected at its left end by 
a pin member 66 to a depending lever arm 67, which in turn is connected to 
a transverse pivot shaft 68. The rear end of the pivot shaft 68 carries a 
rear arm 69 which is connected to a depending pedal connecting rod 70, 
which in turn is connected to a corresponding pedal 63. Thus, when that 
particular pedal 63 is depressed, the connector flange 40 is pulled to the 
left causing the corresponding second toggle member to pivot clockwise 
about the pivot pin 39 relieving the pressure between the locking tongue 
41 and the abutment member 42, thereby permitting the tension in the 
string member 45 to rotate the tuning arm 35 in a counter clockwise motion 
about the tuning shaft 32. Thus, the depression of that particular pedal 
63 will relieve the tension in the corresponding string 46 to lower the 
tone of that particular string. 
One of the connecting rods 59 from the connector flange 37 terminates in a 
pin 72 in a depending lever 73 fixed on a transverse shaft 74 carrying a 
toggle arm 75 pivotally connected to toggle arm 76 which forms one arm of 
a bell crank lever 77, which in turn is pivotally connected to the knee 
lever 64, as illustrated in FIG. 5. Thus, movement of the knee lever 64 to 
the right, as illustrated by the arrow in FIG. 3, will cause that 
particular rod 59 to pull the connector flange 37 and the first toggle 
member 36 toward the left of FIGS. 6 and 8 causing the entire lever member 
34, including the tuning arm 35, to rotate clockwise and tighten the 
corresponding string 46, in order to raise the tone of that string. 
In a similar manner, another connecting rod 60 terminates at its left end, 
in FIG. 6, in a connector pin 82 in a depending lever 83 secured to a 
transverse rotary shaft 84. Fixed to the transverse shaft 84 is a 
depending arm 85 to which the knee lever 65 is pivotally connected, (FIG. 
5). This linkage permits the knee lever 65 to be rotated to the left, in 
FIG. 3, in order to pull the flange 40 to the left, thereby tightening or 
tensioning the corresponding string 45 and elevating the tone of that 
particular string. 
The depending arms 77 and 85 of the knee levers 64 and 65 may be provided 
with stops 86 and 87, as illustrated in FIG. 5. The transverse rotary 
shaft 68 in the pedal linkages may be provided with counter-rotating 
spring members 88, if desired. 
Each of the first toggle members 36 is rotatably biased about the tuning 
shaft 32 in a clockwise direction by a spring 78, while each of the second 
toggle members 38 is rotatably biased about the tuning shaft 32 and pivot 
pin 39 in a counter-clockwise direction by a spring 79. 
Each of the connector rods 59 and 60 has its right end threaded and 
connected to an adjustment head 80 in order to individually adjust the 
lengths of the connecting rods 59 and 60, and therefore the tonal quality 
of the instrument 10. 
A safety or tie wire 89 may be inserted transversely through corresponding 
holes in the string bar 47, in order to secure the string bars 47 loosely 
together. Thus, if a single musical string 46 breaks, its corresponding 
string bar will be tied to the other string bars 47, to prevent any single 
string bar from snapping rapidly upward, and possibly injuring the 
performer. 
It will therefore be apparent that a stringed musical instrument of the 
guitar resonator type adapted to be played upon a horizontal table is 
provided with a string structure, which in essence shortens the effective 
length of the string, but also provides a string structure which removes 
substantial load and pressure from the vibrating musical string per se. 
The invention made in accordance with this invention also reduces the 
string breakage by eliminating the chafing contact between the musical 
strings and the bridge. 
Furthermore, the tonal qualities of the instrument are improved by the 
substantial elimination of string pressure against the resonator. 
Because of the effective shortening of the length of the musical string 46, 
the occurrence of overtones is reduced. Moreover, the travel of the pedal 
or knee lever is slightly reduced in changing the tension on the strings 
to produce different tones. Such reduced action occurs because of the 
greater catenary or sag of a longer string than a shorter string. 
Also in a preferred form of the invention, the top surface of the resonator 
frame 19 is sloped gradually downward toward the tail end of the 
instrument as clearly illustrated in FIGS. 3, 6, and 8. Such sloping not 
only improves the appearance of the instrument, but also slightly shortens 
the overall length of the string member 45. 
The musical instrument 10, made in accordance with this invention, may be 
used either as an acoustic or an electrical guitar type instrument. For 
electrical use, an electrical pick-up 90 is incorporated between the fret 
board 21 and the resonator frame 19 (FIGS. 1, 3 and 6), and conventional 
electrical circuitry 91 (FIG. 4) and an amplifier, not shown, is utilized.