Apparatus For Adjusting The Tension Of An Elongated Stretched Filament

Abstract

There is disclosed apparatus for turning a rotatable pin for adjusting the tension of an elongated stretched filament attached to the pin or to a shaft which is geared or coupled to turn with the pin. A receiving receptacle engages the pin and is connected through a coupling mechanism to a converter for transforming energy to mechanical motion, whereby the mechanical motion is coupled to the receiving receptable to turn the pin and adjust the tension of the elongated stretched filament.

Description

THE DISCLOSURE

The present invention relates to apparatus for adjusting the tension of an elongated stretched filament and more particularly to adjusting the tension or pitch of vibrating strings on musical instruments.

In the field of stringed musical instruments, it has been the general practice to turn manually pins or pegs coupled to the strings to adjust the pitch of the vibrating strings. For this purpose, some instruments, such as the piano, have special wrenches and tools to provide a mechanical advantage to the operator. Although such manual methods and tools have served their purpose, they have not proved entirely satisfactory under all conditions of service for the reason that considerable difficulty has been experienced in controlling and limiting the application of force and difficulties encountered in the accurate adjustment of tension and pitch.

Those concerned with the design and playing of stringed musical instruments such as guitars, banjos, ukeleles, lutes, dulcimers, sitars, violins, celloes, bass violins, and the like, have long recognized the need for an automated device for the adjustment of tensions of the strings. The present invention fulfills this need.

One of the most critical problems confronting performers playing stringed instruments has been the repeated accurate tuning and retuning of the instrument by the manual adjustment of tension and pitch of the strings. The screws or pegs of the instrument are generally turned by the fingers of the player resulting in considerable physical stress and fatigue with repeated adjustment. The present invention overcomes this problem.

Another problem confronting designers and players of stringed musical instruments has been the accurate adjustment of the tension on the strings for precise tuning. The pegs attached to the strings must be held tightly in the peg box of the instrument with sufficient friction to prevent the peg from rotating under the tension of the string. The more tension on the string, the greater is the friction required to prevent the peg from rotating and the greater is the force that must be applied to overcome this friction. As a result, it is difficult to manually adjust the tension of the strings and tune the instrument. The present invention overcomes this problem.

The general purpose of this invention is to provide a mechanized and automated peg turning device which embraces all the advantages the manual methods and possesses none of the aforedescribed disadvantages. To obtain this, the present invention contemplates a unique arrangement of a motor, gear train and cup to receive and engage the rotatable pin which is coupled to an elongated stretched filament or string whereby the stress and fatigue of manual methods and the resulting inaccuracies are avoided.

An object of the present invention is the provision of "push-button" adjustment of the tension of an elongated stretched filament.

Another object is to provide "push-button" tuning of stringed musical instruments.

A further object of the invention is the provision of automated tuning for the accurate and precise adjustment of stringed musical instruments.

Still another object is to provide the automatic adjustment of the tension and pitch of the vibrating strings of a musical instrument where a pre-determined tension cannot be exceeded.

Yet another object in the present invention is the provision of a hand held, motor driven, tuning mechanism for adjusting the tension of the strings of a musical instrument.

A still further object is the provision of electrical tuning of stringed musical instruments with a substantial mechanical advantage over manual methods.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIG. 1 illustrates a side view, partly in section, and partly in block diagram, of an embodiment of the invention;

FIG. 2 shows a pictorial view of another embodiment of the invention;

FIG. 3 is an electrical circuit diagram for operating the motor of FIGS. 1 and 2;

FIG. 4 illustrates a pictorial view of the physical appearance of a preferred embodiment of the invention; and

FIG. 5 illustrates the application of its invention to tuning a stringed musical instrument.

Turning now to FIG. 1, a converter for transforming energy into mechanical motion or motor 7 is connected to coupling means or gear train 9, power being supplied to motor 7 through leads X and Y. Gear train 9 is further connected to plate 11 of clutch 10. Plate 11 further engages plate 13 of clutch 10 which plate is connected to shaft 17 passing through enclosing container wall 19 and further connected to receiving means or to socket 21. Plate 13 is further biased with respect to wall 19 by spring 15 placed over shaft 17 and located between plate 13 and wall 19.

FIG. 2 illustrates a pictorial view of motor 7 having shaft 29 thereof connected to worm gear 27 which further engages the teeth of circular gear 25. Circular gear 25 is centrally attached to shaft 17 which in turn is connected to socket 21 having an opening 23 therein to receive the tuning pegs or pins located on the peg box of a stringed musical instrument.

The circuit diagram of FIG. 3 shows leads X and Y from the motor attached to poles 33 and 31, respectively, of a double-pole-double-throw switch S2. Pole 31 is associated with section (a) of switch S2 and pole 33 is associated with section (b) of switch S2. In section (a) of S2, pole 31 may be moved to engage either contact 35 of contact 37. Similarly, in section (b) of S2, pole 33, which is mechanically connected to pole 31, may be moved to make contact with either contact 39 or contact 41, respectively. Contacts 37 and 39 of switch S2 connected together and are further connected to pole 43 of switch S1, a single-pole-single-throw switch. Pole 43 may be moved to engage contact 45 which is further connected to battery contact 49. Contacts 35 and 41 of switch S2 are connected together and to battery contact 51. Battery 47 is connected between battery contacts 49 and 51. Instead of a battery, a circuit for converting AC to DC power well known in the field of electronic power supply circuits can be used and operated from a source of 110V, 60 cycles AC.

FIG. 4 shows the container or enclosure configuration which supports the components illustrated in FIGS. 1, 2, and 3. Container 53 is a convenient shape easily and comfortably held in the hand of the operator. Rocker arm 55 is connected to the poles of double-pole-double-throw switch S2 of FIG. 3. Socket 21 with opening 23 therein is mounted at one end of container 53 opposite and remote from the end grasped and held in the hand of the operator thereby providing a mechanical advantage.

FIG. 5 illustrates container 53 in the hand of an operator with the operator's thumb depressing rocker arm 55. Socket 21 is shown engaging peg 57 which is connected to peg box 59 of a stringed musical instrument.

Operation of the invention can best be understood by turning first to FIG. 3. Switch S1 is closed by moving pole 43 to engage contact 45. The operator then moves double-poles 31 and 33 of switch S2 to engage contacts 35 and 39 thereof, respectively, applying power to motor leads X and Y and causing motor 7 of FIG. 2 to be activated. Shaft 29 turns worm gear 27 which rotates circular gear 25, and in turn rotates socket 21. The rotation of socket 21 can be reversed by moving double-poles 31 and 33 to make contact with contacts 37 and 41, respectively. Therefore, socket 21 can be rotated in either direction to increase or decrease the tension of a string coupled to the peg of a stringed musical instrument engaged by socket 21. Although not illustrated, it is also possible to reverse direction by using shifting gears similar to the transmission of an automobile. It is also contemplated to extend shaft 17 on both sides of gear 25 as illustrated in FIG. 2 and to make socket 21 removable from shaft 17 so it may be attached to either end of shaft 17 to obtain the desired direction of rotation to increase or decrease tension. In addition, other types of gears may be used in addition to worm gear 27 and circular gear 25 such as a spur gear and circular gear or a circular gear gear train having parallel axes of rotation.

The stalling torque of motor 7 and the size of circular gear 25 can be selected such that, as the tension of string is being adjusted, the motor will stall when the force on the string reaches a pre-determined value, thereby preventing accidental breakage by applying too much tension to the string.

Another alternative for preventing accidental string breakage is illustrated in FIG. 1 where clutch 10 is provided having a maximum friction force between plates 11 and 13 of a pre-determined magnitude set by spring 15, whereby clutch plate 11 will slide against clutch plate 13 when the tension on a string being adjusted exceeds a pre-determined force. It should be noted that other clutch arrangements may be utilized which have the characteristics of limiting the maximum tension which can be applied a string being adjusted.

Although not illustrated, it is possible to automate the tuning process by providing frequency measuring apparatus which is used to control the rotation of shaft 17 to tune a given string to a precise frequency of vibration.

As illustrated in FIG. 5, the portion of container 53 which is grasped by the hand of the operator is oppositely disposed from socket 21 and the shaft of socket 21 is substantially perpendicular to the palm of the operator's hand to provide a mechanical advantage to minimize the forces on the hand of the operator. Container 53 extends from substantially the heel location of the operator's hand through the space between the operator's thumb and index finger with socket 21 mounted at the end of the container nearest the thumb and index finger of the operator. Pin 57 fits into opening 23 of socket 21 and is rotated as socket 21 rotates. The operator depresses rocker arm 55 of switch S2 in one direction to rotate socket 21 in the reverse direction. Therefore, tension on a string can be increased or decreased by "push-button" operation of rocker arm 55. Although pin 57 is illustrated as attached directly to string, many instruments utilize a gear train between the pin and a shaft connected to the string.

Although the present invention is contemplated for use with musical stringed instruments such as guitars, banjos, ukeleles, violins, celloes, lutes, dulcimers, sitars, and other stringed instruments whose tuning pegs are normally adjusted manually by the use of the fingers of the musician or operator, it should be clear that the invention can be used for tuning larger stringed instruments such as harps and pianos by providing the appropriate force required. By utilizing a high mechanical advantage, a powerful motor and an appropriate gear train, it is possible to develop a pull of 150 pounds or more to tune the strings of a piano or turn the tuning pins of a harp.

It now should be apparent that the present invention provides a circuit arrangement which may be employed in conjunction with a motor and socket device for engaging and turning the tuning pegs of a musical stringed instrument to adjust the tension and resulting pitch of the vibrating strings.

Although particular components, etc., have been discussed in connection with a specific embodiment of a tuning device constructed in accordance with the teachings of the present invention, others may be utilized. Furthermore, it will be understood that although an exemplary embodiment of the present invention has been disclosed and discussed, other applications and circuit arrangements are possible and that the embodiments disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention.

Claims

What is claimed is:

1. Apparatus held in the hand of a human operator for adjusting the tension of strings on a musical instrument comprising:

a container having a substantially rectangular form which is shaped to be grasped and held in one hand of a human operator, said container having a depressed area along one edge juxtaposed the position of the thumb of the operator for mounting a thumb operated switch therein, said container extending from substantially the heel location of the operator's hand through the space between the operator's thumb and index finger;

an electric motor mounted inside said container for transforming a source of direct current electrical energy into mechanical motion;

a shaft rotatably mounted through the wall of said container adjacent the end of said container held nearest the thumb and index finger of the operator, said shaft being substantially perpendicular to the palm of the operator's hand when the container is held therein to provide a mechanical advantage related to the distance from the center of said shaft to the end of said container held nearest the heel location of the operator's hand;

a gear train mounted inside said container and connected between said electric motor and said shaft for converting the mechanical motion of said motor to a rotating motion for turning said shaft;

a socket connected to said shaft external to said container, said socket being shaped to engage a tuning peg of a stringed musical instrument, whereby each string of the instrument is tuned as said peg is turned by said socket;

a pair of contacts for connection to the terminals of a direct current electrical energy source;

a thumb operated double-pole-double-throw switch mounted in said depressed area of said container, said switch being connected to said pair of contacts in a manner to connect said motor in a given polarity to said pair of contacts when the poles of said switch are moved in one of the double-throw positions and to connect said motor to said pair of contacts in a polarity reversed from said given polarity when said poles are moved in the other of said double-throw positions, whereby said motor is operated in a forward and reverse direction to increase and decrease the tension of each string.

2. The apparatus as described in claim 1 wherein said motor has a pre-determined stall torque which stops said motor when the tension on said string of the musical instrument reaches a pre-selected force.