US1419919A - Master tuning fork and supporting resonator - Google Patents

Description

J. C. DEAGAN.

MASTER TUNING EORK AND SUPPORTING RESONATOR.

APPLICATION FILEDIFEB. a, 1920.

' PatentedJune 20, 1922.

1. C. DEAGAN. MASTER TUNING FORK AND SUPPORTING RESONATOR.

APPLICATION FILED FEB. 3, I910.

Patented June 20, 1922.

r 2 SNEETS-SHEET 2.

vE x1511 6 40611470 Ill I.

UNITED STATES,

PATENT OFFICE.

JOHNC. DEAGAN, OF CHICAGO, ILLINOIS;

Specification of Letters Patent.

PatentedJune 20, 1922.

Application filed February 3, 1920. Serial N0. 356,059.

To all whom it may concern Be it known that 1. Joint C. Duncan, a citizen of the United States and a resident of the city of Chicago, in the county'of Cook and State of Illinois, have invented certain new and useful. Improvements in a Master Tuning Fork and Supporting Resonator; and I do hereby declare thatthe following is a full, clear, and eXact description of the same, reference being bad to the accom- I panying drawings, and to the numerals of reference marked thereon, which form a part of thisv specification.

This invention relates to improvements in a master tuning fork and supporting resonator and more particularly to a master tuning fork and resonator in which the volume of the sound emanating therefrom may be regulated.

As a master tuning fork is used when exceedingly accurate pitchisdesired, as forexample in orchestra work or when used by piano tuners for tuningtheir own forks, it is particularly desirable that very exact vol ume adjustment between the master fork and its supporting resonator beobtained. The fork is made of vibrating metallic parts while the resonator depends on a vibrating body of air for its effect. The two therefore, cannot keep in perfect tune with each other when atmospheric conditions change, and provision is therefore needed for adj ustment.

In order that the tuning fork may not be injured by handling, it is desirable that it rest on the support at all times and that a handle be provided by which it may be carried about.

It is an object of this invention to provide a m aster tuning fork having a supporting base which also acts as a sound amplifier or resonator. g

It is another object of this invention to provide a master tuning fork having a resonant supporting base and having a me chanically actuated striker mounted on the base for setting up vibrations of the forks.

It is a further object of this inventionv to provide a master tuning fork having a r-eso nant supporting base and having a non-metallic handle whereby the instrument may be moved about without the heat of the hand affecting the vibrations thereof.

It is an important object of this invention to provide a master tuning fork having a supporting base including a resonator and having means mounted in the supporting base whereby the volume of the resonator may be regulated.

ltis another important object of this in ventlon to provide a resonant support for a tuning fork having regulable valves whereby the interaction between the fork and the resonant support may be controlled to secure an adjustment of the volume of sound. emitted from the instrument. I

Qther and further important objects of this invention will be apparent from the disclosures in the drawings and specification.

The invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described.

On the drawingsbig. 1 1s a mole elevation of a master tuning fork and resonator embodying the principles of this invention.

Fig. 2 is an end elevation of the same.

3 is a section. on line 3-3 of Fig. 2. Fig. 4- is a section on line 44 of Fig. 2. Fig. 5.isan enlarged detail showing a method of attaching a sliding cover plate orvalve over an aperture in the supporting resonator of this invention. Figs. (3 and 7 are enlarged details, partly n. section, showing amethod of attaching the actuating spring'for the striker mecha nism. i

Fig. 8 is a vertical. section taken through the resonant supporting base of the invention showing a modified method, of securing the bottom plate herein. i

As shown onthe drawings- '1he reference immoral *1. indicates a metallic tuning fork which is supported by a resonant base 2 and which is set vibrating by'the striker 3. The tuning forkl comprises the fork members 4i integrally connected to the stem 5 which is provided with a shoulder 6 and which is reduced in diameter above said shoulder and thrcadedat its upper portion. Supported on the shoulder 6 and engagedvover the stem 5 is a knurled washer 7 which is preferably constructed of non-rusting metal. Engaged around the inner handle 5 and supported on the washer '7 is ferrule or outer handle 8 which is constructed: of wood or other fibrous material. A knurled,flat-headed,internallythreaded end piece 9 preferablyof the same material as the washer 7 engages the threads and the upper portion of the stem 5 and serves to secure the outer handle in position thereon.

The supporting base 2 is constructed of resonant material, and comprises the hollow cylindrical portion which is provided with a lower flange 11 and a top portion 12 having an aperture 13 centrally formed therein, all of said portion being preferably formed from a single piece of material. Formed centrally on the top portion 12 and above the aperture 13 is the vertical fork support 1 1 which is cut through at its lower portion to form a continuation of the aperture 18. The upper portion of the support 14: is reduced to form a boss 15 which is engaged in a recess in the handle 5 between the fork members 1, and acts to support the fork in position on the support. The sup port 14 is of such height that the lower ends of the fork members a are normally positioned opposite the aperture 13.

As shown in Fig. 1, the boss 15 is tapered whereby the fork may be firmly but removably secured thereon. As shown, the tapered boss does not contact the surface of the fork until well inside the ordinary outline of the yoke or the junction of the tines 6.. thus obviating any change of the fork vibration due to surface contact. To accomplish this the recess which receives the boss 15 is provided with an enlarged mouth 39 affording a shoulder flush with the shoulder on the boss 15.

For varying the volume of sound in the resonator is a body 16, preferably constructed of soft rubber to serve to a greater or less extent according to its position as an obstacle to the passage of the sound vibrations that enter the chamber 2 through the aperture 13. Said obstacle 16 is supported inside the supporting base by means of a metallic disk 17 which has a vertical peripheral flange 18 and a central internally-threaded boss 19. As clearly shown in Figs. 4; and 8 the disk 17 is supported in position by the fri '"tional engagement of the flange 18 with the inner walls of the cylindrical portion. 10. Engaged in the threaded boss 19 is the bolt 20 which is secured in position relative to the disk 17 by the lock nut 21.. The bolt 20 is engaged in a central recess in the obstacle 16, rotatably secured on said bolt by the boss 22 which is forced therein. As shown in Fig. l, the distance of the obstacle 16 from the aperture 13 may be varied, thus varying the volume of the sound given by the instrument. To secure a greater volume in the base the disk 17 may be inverted, shown in Fig. 8. To further vary the volume, the disk 17 may be moved longitudinally within the casing; thus it may be seen that said disk also acts as a valve to vary the volume.

As a further means of varying the amount of volume and amplification the slidably adjustable valves 23 are provided for the aperture 13. Said slidable valves 23 are provided with longitudinal slots and are secured in position on the vertical support 14; by the set screws 24- which engage the slots therein and which may be loosened to allow adjustment of the covers, as shown. in Fig. 5.

The striker 3 which is constructed of felt, rubber, or other suitable material is secured to the lower end of a bar 25, said bar 25 being provided at its opposite end with a finger grip 26 and with transversely extending forks 27. Said forks 27 extend over the outside edges of one of the fork members l, and at their outer ends are pivoted on the upper end of the vertical support Just below the boss 15 is a bushing 15 which is constructed of felt or other resilient material. lt surrounds the pin to which the forks 27 are pivoted. The forks 27 are also connected at the lower part of their outer end by a pin 28 which is encased in a rubber sleeve 29.

A longitudinal depression 30 is provided in the vertical support 14: on the side adjacent the striker 3. Paid depression 30 is adapted to receive a spiral spring 31 the lower end of which secured to the vertical support 14; by means of the set screw 32 and the upper end. of which is secured to the pin 28 around the rubber sleeve 29. A rubber or felt cushion 33 is seen red in the depression 30 to hold the spring 81 from contact with the verti. -al support 14;.

riesilient projections 3 1 are provided on the bottom of the flange 11 and prevent the metal supporting base from marring furniture on which it might be placed and also tend to insulate the resonator from any addi tional rcsonant effect or vibrations which might be produced by the supporting object.

The operation is as follows:

To set the fork in vibration the finger grip 26 is pressed. inwardly thus tensioning the spring and moving the striker 3 away from the fork -11. llpon releasing the finger grip the tension of the spring 31 exerts a donniward pull on the forks 27, pulling the bar 25 inwardly and causing the striker :5 to strike the fork and start it vibrating. By the use of this mechanical striking arrangement danger of damage to the fork is minimixed and a convenicn t method of striking is noride-l. The handle 8 also makes possible the carrying about of the fork and the supporting resonator without danger of damage thereto. The fork may be removed from the boss 15 when it is desired. to use it without the resonator, or for packing.

The resonator adjustments itl'GPlOVlLlGd. to enable the tone of the resonator to be exactly adjusted to the tone of the fork, and thus aflord perfect, sympathetic tonal adjustment of the entire instrument. Coarse adjustment is made by changing the position of the disk 17 while the finer adjustments are made by. changing the obstacle 16 and the slidable valves 23. By the cooperative action l l t) of these valves it is possible to make very exact adjustments.

The tuning fork and supporting resonator disclosed in this application is particularly adapted for use by members of orchestras, as it is possible for each member to have a fork at his home or room and thus eep his instrument tuned to the proper pitch at all times. This tuning fork is especially valuable for such purposes because of the ad j ustments of volume which are possible.

I. am aware that numerous details of construction -may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted otherwise than necessitated by the prior art.

I claim as my invention- 1. The combination with a resonant supporting member of a tuning fork mounted thereon, a striker for vibrating the fork pivoted on the supporting member, a spring for actuating the striker secured to the supporting member, and resilient non-metallic means between one end of the spring and the supporting member.

2. The combination with a tuning fork of a resonant supporting base therefor and means inside said supporting base for varying the resonant effect thereof.

3. A resonant support for a tuning fork comprising an apertured hollow base portion, slidable valves for varying the apertures therein, an obstacle mounted inside the base portion, and means whereby the position of said obstacle may be changed to vary the degree to which it hinders the passage of sound through said apertures.

44. The combination with a tuning fork of an apertured resonant support therefor and means adj ustably mounted beneath the aperture for varying the resonant effect of said support.

5. A resonant support for a tuning fork comprising a hollow base member, an upwardly extending portion on the base member adapted to engage the fork between the vibrating portions thereof to support it, and means adjustably mounted inside the base member for varying the resonant effect thereof.

6. A tuning fork, a handle therefor, a resonator beneath said fork, means for detachably supporting said fork on said resonator, and a spring actuated striker mounted on said supporting means.

7.. The combination with a tuning fork having a tapered recess between the tines thereof, of a resonant supporting base and an upwardly projecting tapered member on the supporting base engaged in the tapered recess without contacting the outer surface of the fork.

8. The combination with a tuning fork of a resonant support therefor, of regulable valves whereby the tone volume of the instrument may be adjusted.

9. A tuning fork and a support therefor engaging the fork between the tines, the material of the fork being cut away adjacent said point of engagement.

10. A tuning fork having a recess between the tines thereof, and a supporting member seating in said recess the mouth of said recess being larger than the body thereof.

11. A tuning fork having a conical recess between the tines thereof, a support having a tapered end fitting said recess, the material of the fork adjacent the mouth of said recess being cut away forming a shoulder on the fork and the material of the support being cut away forming a shoulder on said support, the shoulders being flush when the support is in said recess.

12. A tuning fork, a support therefor including a connection extending from the body of said support into the space between the tines, and from there into contact with the fork.

13. The combination with a tuning fork, of a resonator secured thereto, and means inside the resonator for varying the resonator effect thereof.

14. A tuning fork, a resonator, and means securing the resonator to the fork, said means extending from the resonator into the space between the tines, and from there into contact with the fork.

In testimony whereof I have hereunto subscribed my name in the presence of two subscribing witnesses.

JOHN C. DEAGAN.

IVitnesses CARUTON HILL, EARL M. I-IARDINE.

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