US1768261A - Guitar - Google Patents

Description

A. LARSON @Unia Filed Feb. 25, 1927 Patented June 24, 1930 UNITED STATES AUGUST LARSON, 0F CHICAGO, ILLINOIS GUITAR Application led February 25, 1927. Serial No. 170,875.

My invention relates to guitars and like stringed instruments, and more particularly to means for reinforcing the same against the strain of the strings, and my main ob- 5 ject is to provide a novel element to counteract the buckling .of the instrument from the strain referred to.

A further object of the invention is to provide means to adjust the position of the instrument neck relative to that of the body, whereb to control the distance of the finger board rom the strings.

A still further object of the invention is to provide a spacing element for the body of the instrument near the top of the same, whereby to counteract the pressure of the neck and reinforce the body at its weakest region.

Another object of the invention is to provide a novel combination of lever and pivotal elements designed to lend the instrument suficient rigidly to render adjustments stable under the strain of the strings and the effects of climatic changes.

A final, but nevertheless important object of the invention is to so strengthen the instrument that lighter material may be employed for its construction and improved tone secured in consequence.

With the above objects in view and any others that may suggest themselves from the specification and claims to follow a better understanding of the invention may be had by reference to the drawings, in which- Figure l is a bottom plan view of a typical guitar improved with one form of mylnvention, the bottom of the instrument being removed;

Figure 2 is an enlarged section on the line 2-2 of Figure 1, and partly broken away;

Figure 3 is a view similar to Figure 2, but showing a modification; and

Figures 4 and 5 are, respectively, sections on the lines 4 4 and 5-5 of Figure 2.

Referring specifically to the drawing, it will be noted that the ends of the guitar body are reinforced from within by blocks a and the base b of the neck strengthened by a screw c. The finger board d, is secured to the tcp of the body by screws e whereby to aline and adjust the finger board relative to the strings, the screws entering a cross-brace f depending from the top.

Plates G of hardwood are secured on the inner surfaces of the end blocks a, the grain of the plates crossing that of the blocks in order to neutralize warping or distorting tendencies in the parts secured. The plates G are faced with harder material, such as strips H of metal or Celluloid.

The top of the instrument is strengthened by a -rib-`formation, as shown, and next beneath the top structure I provide a horizontal dowel stick I longitudinally of the body. Thedowel stick may be of reinforced hardwood, or of steel tubing as illustrated, being secured in the ends of the body by dowels J as shown in Figure 2, or screwed with itsends into the yfacing strips H, as indicated in Figure 3. In Figure 2, the material of these stripsby its hardness prevents therends ofthe tubular dowel stick from ycutting through into the ends. In 'Figure 3, the strips are shown secured by screws, as indicated by dotted lines.

Belowthe dowel stick I is situated a straining rod Lof steel, this rod extending inclinedly from a relatively high position in the outer end of the body to a relatively low position in the inner end thereorf.y in the outer end, the straining rod extends through a bore to the exterior, and -isscrew-threaded to receive a rounded nutr M. The connection of the straining rod here is intended to he as nearly in line withthe dowel stick as practicable in order that the hold on the particular body-end be taken where the latter is well braced. Also, by locating the nut M, approximately midway between .the top and bottom ofthe instrument, it can serve as the end-pin with which instrumentsof the guitar or violoncello type are usually provided;

In the inner end of the instrument body, the corresponding end of the strainingy rod is anchored in either of two ways according to the drawing. Thus, Figures 1 and 2 show a form wherein the rod is shaped into a hook LI to pass through the end block a, engage the base b of the instrument neck and return in part by lodging in the block. In Figure 3,21 modified iorm is shown, wherein the rod rod to brace said body about said neck to is formed with a. flared head L2, which is equalize the strain of the instrument strings.

lodged in the base of the neck.

firm spacing element for the ends of the instrument body, to prevent them from yielding to the pulling strain ot the strings as transmitted by the neck. Being immediately underneath the top structure, the dowel stick braces the latter against collapsing or warp ing tendencies at its weakest points, that is, in the region of the sound hole and the converging body sides.

As to the straining rod L, it will be apparent that the advance oi' the nut M will draw on the rod and the neck base b to deflect the neck and thus counte act the pull on the same by the strings. Thus, where such pull, possibly aided by the yield of the parts from climatic influences, has drawn upon the neck with a bucklingl effect on the instrument and a departure of the finger board from the strings, the simple adjustment of the nut M may be invoked to restore the poise or line of the instrument.

The mechanics of the above adjustment consists in the service of the inner terminal of the dowel stick I as a pivot, of a line from said terminal to the anchoring hook Ill-or head L2 as a radius, and of the straining rod L as a lever. Thus, a favorable leverage is had by having the terminal at a high point and the anchoring point at a low one; also, the proximity of the bearing area for the nut M to the line of the dowel stick I provides a firm foundation for the source of the adjustment-as previously mentionedand relieves the corresponding wall of the instrument body of straining or warping pressure.

lVith the instrument strengthened in the regions subject to strain by the use of the novel improvements described, it is safe to build the instrument of lighter woods whereby to secure greater resonance and improved tone. Thilo the drawing illustrates the preferred embodiments of the invention, the same may admit ot other changes and refinements, and I desire to include such changes and refinements as coming within the spirit and scope of the invention as defined in the appended claim.

I claim:

A neck-straightening device for guitars and like instruments having a sound body and neck adjustably secured thereto, comprising a dowel stick extending lengthwise through said sound body in the upper portion thereof, a straining brace rod extending through said sound body from a point adjacent the dowel stick at the outer end of the instrument sound body and disposed at an inclined angle to said dowel stick to engage the neck of the instrument adjacent the base thereof, and means at the outer end of the In testimony whereof I affix my signa- In effect, the dowel stick I serves as a ture.

AUGUST LARSON.

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