Bridge with pickup for hybrid arched top guitar or the like

Abstract

An arched top bridge upper section including a wood top section slotted to accept a string saddle that may be plastic, bone or similar material. The wood section is laminated or affixed to a lower metal section. A slot completely through the wood section exposes a top flat surface of the metal section. A piezo pickup element installed in the slot below a solid or segmented string saddle element is pressed uniformly against the metal section by string pressure on the string saddle to ensure even response on all strings. Transfer of string energy is more efficient than standard all-wood construction, resulting in greater sustain of plucked notes and a broader frequency response. An arch top guitar utilizing this bridge construction has more similar tonal and sustain characteristics to a typical flattop acoustic guitar while consistent contact with the piezo element results in even string-to-string output and response.

Claims

1. A bridge assembly for a stringed musical instrument, comprising: a bridge having an upper element and lower element; the lower element having a length with an upper surface and a bottom surface, the lower element comprising a first material; the upper element having a length with an upper surface and a bottom surface, the upper element comprising a second material that is less dense and less rigid than the first material, the length of the upper element being less than the length of the lower element, the upper element secured to the lower element such that the bottom surface of the upper element is in contact with and extends along the upper surface of the lower element, the upper element having an elongated slot extending through it from the bottom surface of the upper element to the upper surface of the upper element so as to form a passage from the upper surface of the upper element to the upper surface of the lower element; a transducer mounted on the upper surface of the lower element within the slot; and a saddle within the slot, operatively engaging the transducer and projecting from the slot through the upper surface of the upper element for receiving at least one string of the musical instrument.

2. The bridge assembly of claim 1, wherein the first material s metal.

3. The bridge assembly of claim 2, wherein the metal is aluminum.

4. The bridge assembly of claim 2, wherein the second material is wood.

5. The bridge assembly of claim 1, wherein the bridge is elongated, and wherein the slot, the saddle, and the transducer extend in a lengthwise direction of the bridge, for receiving a plurality of strings of the musical instrument, wherein the strings extend in a common direction, and the lengthwise direction of the bridge is transverse to the common direction of the strings.

6. The bridge assembly of claim 1, wherein the lower element is mounted on a bridge base by adjustable posts at two opposite ends of the bridge.

7. The bridge assembly of claim 6, wherein the bridge base has a lower surface that is concave, for mounting on an arched top of the musical instrument.

8. A stringed musical instrument comprising: a bridge assembly according to claim 1, one or more strings of the musical instrument stretched over the bridge saddle; and an electrical output from the piezoelectric transducer to an exterior of the musical instrument.

9. The instrument of claim 8, which is an arched top guitar.

10. The instrument of claim 8, wherein: the one or more strings are a plurality of strings extending in a common direction; the bridge is elongated, and the slot, the saddle, and the transducer extend in a lengthwise direction of the bridge; the bridge is mounted on the musical instrument with the lengthwise direction of the bridge transverse to the common direction of the strings; and the plurality of strings are stretched over the bridge saddle.

11. A guitar bridge assembly for an arched top guitar comprising: an arched top style bridge upper section consisting essentially of a wood top element with an upper surface and a bottom surface; wherein the upper wooden bridge section is attached to a lower metal section, the lower section having a top flat surface and a bottom surface, the bottom surface of the upper section positioned on top of and in contact with the top flat surface of the lower section; wherein the upper wooden section contains a slot that is routed completely through the wood section to expose a top flat surface of the lower metal section; a string saddle positioned within the slot and projecting above the upper surface of the supper section; a piezo pickup element that is installed below the saddle element in the slot so that the piezo element is pressed uniformly against the top surface of the lower metal section by a downward force of string pressure on the string saddle to ensure even response on all strings; wherein the string pressure forcing the saddle element against the piezo pickup element and in turn against the metal lower section of the bridge top section, enhances transfer of string energy more efficiently than a standard all-wood arch top guitar bridge construction, resulting in greater sustain of plucked notes and a broader frequency response, when compared to standard all-wood arched top bridge construction or the use of a solid metal bridge top section; whereby an arched top guitar utilizing the hybrid bridge construction will have more similar tonal and sustain characteristics to a typical flattop acoustic guitar than to a standard arch top guitar while also ensuring consistent contact with the piezo element sandwiched between the saddle and lower metal bridge section resulting in even string-to-string output and response.

12. The bridge assembly claim 11, wherein the string saddle is selected from the group consisting of plastic and bone.

13. The bridge assembly of claim 11, wherein the upper wooden bridge section is attached to the lower section by being laminated or affixed with screws, pins or other mechanical connecting element or elements.

14. The bridge assembly of claim 11, wherein the lower metal section is machined or cast.

15. The bridge assembly of claim 11, wherein the string saddle element is solid or segmented.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For the purpose of illustrating the invention, the drawings show a form of the invention which is presently preferred. However, it should be understood that this invention is not limited to the precise arrangements and instrumentalities shown in the drawings.

(2) FIG. 1 is a perspective view of a representative arched top guitar.

(3) FIG. 2 is a perspective view of a bridge according to the present invention for use with a guitar of FIG. 1.

(4) FIG. 3 is an exploded view of the bridge of FIG. 2.

(5) FIG. 4A is a side elevation view of the top of the bridge of FIG. 2.

(6) FIG. 4B is a top plan view of the top of the bridge of FIG. 2.

(7) FIG. 4C is a cross-section through the top of the bridge, taken along the line A-A of FIG. 4A.

(8) FIG. 5A is a side elevation view of the base of the bridge of FIG. 2.

(9) FIG. 5B is a top plan view of the base of the bridge of FIG. 2.

(10) FIG. 5C is an end view of the base of the bridge of FIG. 2.

DETAILED DESCRIPTION

(11) Referring to the drawings, and initially to FIG. 1, a guitar indicated generally by the reference numeral 10 has a body 12, a neck 14 with frets 16, and a headstock 18. The body 12 typically consists of a carved or formed arched top plate 20, a flat or arched back plate (not shown), curved sides 22 that may be made from either solid or plywood wood material and a provision at the upper bout end of the body to affix the neck 14. The top plate 20 is typically braced with two braces (not shown). The downward pressure exerted by the strings 30 on the top plate 20 through a bridge indicated generally by the reference numeral 40 is supported partly by the braces, and partly by the arched structure of the top plate. The construction of the body 12 may be conventional, and in the interests of conciseness is not further described.

(12) Several strings 30 are attached to an anchorage at a tailpiece 32 near a tail end 34 of the body 12, and extend over the bridge 40 and up the neck 14 to the headstock 18, where they are attached to rotatable pegs 36 of a tuning machine 38. The tension of each string 30 can be adjusted in the usual way by rotating the respective peg 36 to wind string onto or off the peg, thereby increasing and decreasing tension, respectively.

(13) Referring now also to FIGS. 2 and 3, the bridge 40 has a top 42 and a base 44. The base 44 has two feet 46, one at each end, that rest on the guitar body 12 and may be attached to the guitar body in any convenient manner. The base 44 also includes a middle portion 48 that is concave so that it does not contact the guitar body. The bridge base 44 has a flat upper surface 50, and two posts 52 are screw-threaded into holes in the bridge base 44. Two thumbwheels 54 are threaded onto the posts 52, and the bridge top 42 rests on the thumbwheels, so that by rotating the thumbwheels 54, the bridge top 42 can be raised away from the bridge base 44, against the tension in the strings 30, or lowered towards the bridge base 44. This adjustment allows a user to alter the height of the strings 42 in relation to the fingerboard, to select the amount of pressure (called action) the player prefers to press the string down to the fret 16 to sound a note.

(14) A hole 56 near one end of the bridge base upper surface 50 allows an electrical output wire 58 from the bridge top 42 to be led down into the body 12 of the guitar.

(15) Referring now also to FIGS. 4A-4C, the bridge top 42 comprises at least two pieces, a lower element or saddle support 60 of metal, which in this embodiment is aluminum, and an upper element or cap 62 of wood. The wood may be rosewood or ebony, which are used in conventional arch top guitar bridge construction, though other hardwood material is sufficient. The upper element 62 has a slot 64 extending for most of its length. The slot 64 opens through from the lower element 60 to the upper surface of the upper element 62. A piezoelectric element 66 is positioned in the bottom of the slot 64, in contact with the aluminum lower element 60. The piezoelectric element 66 may be of a sort commercially available for piezoelectric bridge pickups of hybrid guitars, and in the interests of conciseness is not further described here. The slot 64 is dimensioned to receive the piezoelectric element 66 snugly. The piezoelectric element 66 is held into the slot by the tension of the strings 30 pressing on the top of the piezoelectric element, and adhesives or other fastenings are not typically necessary although optionally could be added.

(16) At one end of the slot 64, there is a hole 68 formed through the lower element 60, preferably aligned with the hole 56 in the bridge base 44, for the output lead 58 from the piezoelectric element 66 to extend through. The lead may pass through the guitar body 12 to an external amplifier, or may be connected to a preamplifier or control mounted in or on the guitar body 12. All such circuitry is conventional and, therefore, no further description is necessary.

(17) A saddle 70 is mounted within the slot 64, on top of the piezoelectric element 66. The saddle 70 is held in place by the downward pressure exerted on it by the tension of the strings 30. As may be seen in FIG. 2, the saddle 70 may have notches 72 for individual strings 30. The ends of the saddle 70 are shaped as shown at 74 to allow the saddle to automatically position itself properly in the slot 64. That is a common feature of what are called compensated saddles, which are molded in such a way as to allow the different string diameters to play in tune up and down the fingerboard by compensating for the differing string diameters.

(18) In use, the bridge 40 is mounted on the guitar body 12 in the same way as a conventional bridge, the strings 30 are stretched over the bridge, and the guitar may be tuned and played in the conventional manner. The rigidity provided by the aluminum lower element 60 both improves the support for, and thus the reliability of, the piezoelectric element 66 and provides a channel for vibration from the strings 30 to the guitar body 12 and from the guitar body 12 to the piezoelectric element 66. The softer, lighter, and more absorbent material of the wooden upper element 62 increases the tonal warmth and smooths harsh overtones by preferentially absorbing higher frequencies.

(19) Although an example of a six-stringed guitar is shown in the drawings, those skilled in the art will understand how the teachings of the present application may be applied to other stringed musical instruments.

(20) Aluminum is mentioned as the material for the bridge lower element 60, and hardwood is mentioned as the material for the bridge upper element 62, because they have satisfactory and well understood mechanical properties, are easy to machine, and are reasonably economical. However, for the bridge lower element 60, other metals such as steel or brass may be used. For the bridge upper element 62, other moderately stiff and moderately absorbent materials may be suitable.

(21) For the purposes of promoting an understanding of the principles of the invention, reference has been made to the preferred embodiments illustrated in the drawings, and specific language has been used to describe these embodiments. However, no limitation of the scope of the invention is intended by this specific language, and the invention should be construed to encompass all embodiments that would normally occur to one of ordinary skill in the art.