US2788694A - Automatic auxiliary tuning device - Google Patents

Description

April 16, 1957 I R. E. DEARTH 2,788,694

AUTOMATIC AUXILIARY TUNING DEVICE Filed June 14, 1954 Fl'g- 4 60 Fj jf Ronald E. Dearth r I INVENTOR.

34 2 BY 22g 3251i WM 1? KL 3 United States Patent O AUTOMATIC AUXILIARY TUNING DEVICE Ronald E. Dearth, Lima, Ohio Application June 14, 1954, Serial No. 436,541 4 Claims. (Cl. 84-312) The present invention relates to a quick-change pitch adjusting device for the customary strings on a Hawaiian guitar which device, because of its unique construction and functioning, is being currently marketed under the title Automatic Tuning Changer.

Identified somewhat more explicity, the invention has to do with a tuning changer which provides for selective tuning changes with a flick of a simple readily accessible key changing handle or lever, a device which may be supplied with a guitar at the time of purchase of the latter or may be easily and quickly installed by anyone desiring the use of such a device after having once purchased the guitar without it.

Stated somewhat more explicitly the subject matter of the invention has to do with a simple attachment or accessory which is light in weight, does away with the necessity of lugging around a heavy double or triple neck guitar, and is such that it saves much valuable time for the teacher, student and professional alike, gives the user instantly and accurately three tunings (A, E and C-sharp minor) at the touch of a finger, the construction being such that it may be attached in a few minutes to any Hawaiian, electric or steel guitar whether it be wood, metal or commercial plastics and the use of which makes it possible to afford the user desirable chord voicings on a single guitar equivalent to that of the heavier double and triple neck guitars.

In order to identify the nature of the invention it is to be herein known as an improvement on a similarly constructed and performing tuning changer covered in Patent 2,603,119 granted to me on July 15, 1952 and which has to do with collectively changing the pitch of the second, third and fifth strings automatically whereby the guitar may be tuned up to A, the standard voice or pattern, and quickly shifted from A to E and then to Gsharp and from C-sharp back to E and then back to A, placing at the command of the guitarist facilities enabling him to have three optionally usable and distinctive pattern tunings on a single guitar for greater range of utility and playing.

The construction in the aforementioned patent and also that herein disclosed may be said to be characterized briefly by a casing with ears making it possible to fasten the casing on the top of the guitar body, a rocker shaft mounted horizontally for oscillation in said casing and provided with individual cams at longitudinally spaced points and provided at one end, exteriorly of the casing, with a handle. On the interior of the casing flat plate members are provided and hingedly mounted and these are confined within the limits of the casing in close eooperating proximity or relationship to the cams on the rocker shaft, these members constituting string tensioning and tuning levers, the upper ends thereof being engageable with the respective cams, with the lower ends being apertured, and a cooperating wall of the casing being apertured with the apertures in alignment with each other to accommodate strings and to permit the same to be attached to and operated by said levers.

2,788,694 Patented Apr. 16, 1957 In carrying out the principles and provisions of the patented construction, Patent 2,603,119, certain setscrews were mounted in one wall of the casing to serve as variable or adjustable stops for cooperating end portions of the pivoted string tensioning levers. It has been found desirable to transfer these setscrews and they are therefore, in this improved arrangement, confined wholly within the limits of the casing where they are concealed and yet perform with requisite certainty and appropriateness.

Another, somewhat more specific feature, of the improvement is that which has to do with the stated levers wherein the same, instead of being provided with the attached setscrews, are in and of themselves L-shaped with the lateral upper ends constituting stop members and having the equivalent function of the stated setscrews.

A still further object of the improvement here is to dispense with the anchoring and pivoting means for the levers shown in the stated patent and to substitute a different and what is believed to be an improved holddown and pivoting construction.

Other objects, features and advantages will become more readily apparent from the following description and the accompanying sheet of illustrative drawings.

In the drawings:

Figure 1 is a fragmentary perspective view of a portion of the body of a conventional Hawaiian or similar guitar showing, among other features, the usual six strings, tail piece and improved automatic tuning changer, the latter constructed in accordance with the invention and having the cover removed.

Figure 2 is a top plan view of the same with the cover omitted.

Figures 3 and 4 are sections on the lines 3-3 and 4-4, respectively, looking in the direction of the directional arrows.

Figure 5 is a perspective view of the cam shaft.

Figure 6 is a view similar to Figure 4 showing a slight modification in a lever construction.

Referring now to the drawings with the aid of reference numerals, the numeral 8 designates the guitar body, which may be said to be of conventional form. This is provided with the usual fretted fingerboard or neck (not shown). It is also here shown as provided with the usual six strings, three of which are denoted by the numerals 10-10-10 and the other three of which are denoted by the numerals 12-12-12. The terminal ends 14 of the strings 10 are anchored in the usual way on the blocklike fixedly secured bridge 16, that is, the bridge which is fastened to the wooden or equivalent top 18 of the guitar body. The tuning changer serves to accommodate the end portions 20-20-20 of the strings 12. The latter end portions 20 are, instead of being anchored on the bridge 16, passed over grooves and beyond the bridge where they are connected to the tuning changer. As already mentioned this changer takes the form of a hollow casing which is here shown as generally rectangular in plan and which is fastened down on the top in spaced parallelism rearwardly of the bridge 16. The main or body portion of the casing is denoted by the numeral 22 and this has a horizontal bottom wall 24 with outstanding ears 26-26 provided with holes for fastening or hold-down screws 28-28 screwed into openings provided in the top 18. On the rear edge the bottom has an upstanding lug 30 with a screw-threaded hole to accommodate the attaching screw 32 for the cover 34 which fits over the body of the casing. The body comprises a front wall 36 and end walls 38-38. This means that the body is open at the top and open at the back and that the cover is of angular cross-sectional form with the flange 40 providing the removable top and the flange 42 providing the removable rear wall. By passing the screw 32 through the hole 44 and connecting it with the lug 30 the cover iS detachably held in place and protectively conceals the mechanism on the interior of the casing. One end wall 38 is provided with a bearing 46 for the adjacent journal portion 48 of a rocker shaft-50. The other end portion 52 bears against the interior of the other end wall 38 and has an axial screw-threaded socket to accommodate the screw-threaded shank 54 of the notched head 56. Milled or otherwise formed in the shaft at suitable spaeed and places are notches 5$-53 which transform the shaft into a cam shaft. On the journal end 48 there is a lateral crank handle or operating lever 6%? which is handily arranged for conveniently shifting the tuning changer from one key to another.

' The strings which are to be tensioned and tuned may be three or more in number depending on the requirements of the guitarist. The principle is the same and therefore it is to be assumed that only three of the strings 12-42-42 are here involved. These string are anchored on fiat plate-like members which are here referred to as rectangular string tensioning and tuning levers 62. There are three of these and they have lateral bends at their lower ends as at 6 which are hooked and hinged in openings provided therefor in an anchoring plate 66. The plate has suitable clearance to permit the feet 64 to rock and it also has a flange 63 along one edge which is riveted or otherwise secured to the bottom wall 24. The intermediate or upper intermediate portions of the respective levers are cooperable with the notched out, portions 53-53 so that the desired cam cooperation is had between the cam shaft and the pivoted levers. The lower portions of the respective levers are apertured so as to allow the headed ends 7% of the strings to be attached or anchored thereto in the manner shown in the drawings. These anchored ends pass through openings provided therefor in the front wall, the openings being denoted at 72. The upper end of each lever is provided with a setscrew or stop screw 74 which is threaded through an opening in the lever and which is at right angles to. the lever and engages the front wall to check the movement of the lever in a direction from left to right in Figures 3 and 4 for example. The numerals 76 are lock nuts which serve to fix the setscrews once they have been adjusted to their proper stopping positions.

It is to be noted that these stop screws 74 are fully confined within the limits of the casing and are properly adjusted after which the lock nuts are tightened and the setscrews allowed to remain as then properly set. In this connection it is within the purview of the invention instead of using the setscrcw 74 and lock nut 76 on each lever to make the lever itself L-shaped as shown for example in Figure 6. That is to say, the setscrew is omitted here and the upper end portion of the lever is bent laterally as at 78 and '73 constitutes the same function of a check or stop for the swinging movement of the lever 62 in a direction from left to right in the drawings. Other than this Figure 6 illustrates the same particulars and hence the same numerals are employed to designate identical parts already referred to in the description. Finally, it is to be mentioned that numerals 8fi50 seen best in Figure 2 are further stops on the end wall 38 to limit the movement of the controller handle or lever 60 from one position to the other that is from a normal A position to anintermediate E position or the other final position which is a C-sharp position.

With respect to tuning instructions it is to be explained that after the changer has been installed, the user may simply place the lever 64) in a forward or down position and tune the guitar to A major low bass with the regular tuning keys (not shown). Next, place the lever or handle 65 in a vertical central straight up position and through the use of a suitable tool the setscrews or stop screws 74 on the interior of the changer, accessible after the cover 34 is off, are adjusted until the guitar is tuned to E major low bass. Here it is necessary tobe sure to adjust only the setscrews that control the proper strings.

and to use the regular tuning keys to tune the fifth string from A to B. Now the user may place the lever of handle 66 again in forward down position, use a tool and adjust the screw that controls the aforementioned fifth string until it is tuned to the pitch of A in A major tuning. inasmuch as C-sharp minor tuning is really a combination of A and E tunings, one will find that after having'carefully followed the above instructions that by placing the handle 6% in back and down position, the guitar will be automatically tuned to C-sharp minor tuning. Returning the lever to vertical straight up position, the guitar will instantly be tuned to E and again changing the lever to forward and down position the guitar is instantly tuned. to. A key or tuning.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. An automatic auxiliary tuning changer of the class described comprising a hollow casing with means for attachment of the same to the top of the guitar body, said casing having a flat bottom attaching wall, a plate superposed on the interior of said bottom wall and having slot means therein, said plate constituting a hold-down device, a plurality of levers having angularly shaped lower ends hingedly attached to said hold-down device, the lower end portions of said levers having openings therein to accommodate the string ends, the upper ends of said levers being provided with setscrews engageable with the front wall of the casing and serving to limit the direction of adjustment of the levers in one direction, said setscrews being confined wholly within said casing, and a handleequipped cam shaft mounted for oscillation in said casing and cooperating with said levers.

2. A guitar string anchoring and key changing attachment comprising, in combination, a casing adapted to be mounted atop a guitar body rearwardly of the usual string accommodating bridge, a shaft mounted for oscillation in said casing and provided exteriorly of the casing with a handily accessible quick change handle which serves, when actuated, to oscillate the shaft, a plurality of string anchoring, tensioning and tuning levers hingedly and detachably secured at their respective lower ends to the interior of the bottom of said casing and having intermediate portions contactable and cooperative with said shaft, the lower hinged ends of said levers having openings therein for attachment of adjacent string-ends thereto, the front wall of said casing having string accommodating openings therein registrable with said first-named openings, said levers having stop members on their upper ends movable toward and from a cooperating wall of the casing to limit the swinging movement of the levers in one direction, said casing embodying a relatively stationary body portion which is open at its rear and open at the top and provided with. end walls having outstanding attaching ears, and a readily applicable and removable cover having horizontal and vertical flanges covering the open top and rear side of said casing and thus rendering the latter tamper-proof and dustproof, the stop members on said levers being confined wholly within the protective limits of said casing and being accessible for handling and adjustment only when said cover is removed.

3. The structure defined in claim 2 wherein said members are setscrews confined wholly Within the limits of the casing, said setscrews being adjustably mounted in screw-threaded holes provided therefor on the upper ends of the respective levers, and each setscrew being provided with a lock nut so that once the setscrew is regulated it can be set to stayin its given position.

4. A guitar string anchoring and key changing attachment comprising, in combination, a casing adapted to be mounted atop a guitar body rearwardly of the usual string accommodating bridge, a shaft mounted for oscillation in said casing and provided exteriorly of the casing with a handily accessible quick-change handle which serves, when actuated, to oscillate the shaft, a plurality of string anchoring, tensioning and tuning levers hingedly and detachably secured at their respective lower ends to the interior of the bottom of said casing and having intermediate portions contactable and cooperative with said shaft, the lower hinged ends of said levers having openings therein for attachment of adjacent string-ends thereto, the front wall of said casing having string accommodating openings therein registrable with said first-named openings, said levers being L-shaped and having their upper ends laterally directed toward and movable toward and away from a cooperating wall of the casing in a manner to limit the swinging movement of the levers in one direction, said casing being wholly closed to protectively encase and house the levers and including a readily applicable and removable cover section permitting access to said levers.

Biederman July 13, 1943 Dearth July 15, 1952

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