US2601801A - Tuning fork with simultaneous multiple frequencies - Google Patents

Description

y 1, 1952 R. J. M. c. LANGLOYS 2,601,801

TUNING FORK WITH SIMULTANEOUS MULTIPLE FREQUENCIES Filed Aug. 6, 1947 Fla.5 2

Patented July 1, 1952 PATENT OFFICE.

TUNING FORK. WITH 'SIMULTKNEUU 8* MULTIPLE FREQUENUIES RmyaIosephMarie Gcile La-ngloys; Saint-019ml,v Seineet.-0ise,, France, assignon to, Society. Etablisscments Herrburgen. .Baris, France, a corporationlof' France Application August 6, 1947*, SerialiNo'. 7.66;,536: In? France April 24, 1945 Section}, PublicLaw 690,1 August8,,1946 Batentexpires April 24; 1965' 16 Claims. 1.

The present" invention relates to a; tuningfork of complex' shape whose excitation by striki'n'g orbyab'owor" any other means generates simultaneously" several fundamental, frequencies.

The object" of the invention will become apparent as the following, detailed. description progresses, reference. being had to' the accompenyingdra'wing; whereini:

Fig. 1" illustratesa standard tuningtfork;

} Figs. 2-8 illustrate various complex-shaped tuning forks" according to the invention,

Fig. 9 is. a sectional viewof a tuning fork according" to the; invention taken' on line' IX"IX ofFi'g: 3, wherein, however; thetunin'g fork is promdedwith damping means, and.

Figs: I'Oandj'll" are. partial viewszof the tunin fork. shown in Fig; 3' provided with different types-of'fdampingf'means.

Leta standardtuningdork 'i' be. considered first on Fig. 1 comprising as well. known a pair of tines" arranged" in spaced parallel" alignment. Let another tuning-fork '2 (Fig: 2) be also considered with no" tail as the firstfork; which a; partof the upper: legs is'replaced by a'fork 4*which is identical with fork l. of'Fig; 1.

Ifthe lowertine of the fork" 2' is' struck" in a vertical direction, the". complex shaped tuning fork (lower tine; tail member 3 and double tine fork 4) will? vibrate as if its upper tine (tail member 3 and fork' 4) were. identical to: the

said lower. tine; the. compound fork will'vibrate asv a.- standard. tuning" fork on its normal pitch.

0n the contrary iflthe upper tine ofthe upper fork 4." is struck i a vertical. direction, the two tuning, forks [and 4 constituted by the three A tines will vibrate, generating simultaneouslythe fundamental, corresponding to the upper fork' 4 and the fundamental corresponding to the lower fork. 2. For in fact" the striking action on the upper tine ofv fork t'will not only vibrate the. small" fork but also its tail' portion 3- and consequently the other tuning fork 2. Naturally. it isv necessary for making the second fork 2' vibrate to adjust its upper leg 3 which has been cut for fixing the aforesaid? fork" 4..

According. to the. same process it will be posslble. to build ('seeFigure' 3) another complexshapedlfork, 2, 4, 6 with three frequencies and so on; the final fork will be fitted with a tail to meetthe service requirements;

The shapes. shown on Figs. 1, 2 and 3 are non rcstrictivait being quite possible'to have, shapes and designs whichv differ widely'from them, as for example those shown on Figs: 4and '5'. The compound, or complex-shaped" tuning fork ac- 23- the latter being provided with a tail 5 corresponding to the tail 5 of Figure 31 As explained for the compound fork in" Figure 2', the compound fork according to Figured, upon a striking action on" the first fork lvibfatesthe tail part-2 and consequently the'first compound fork 2- anditstail portion 6" which makes the second compound fork 6 to vibrate. second compound fork vibrates the tail portion 2 3"which in its turn makes the-third compound fork2-3 to vibrate. As any one" of these forks vibrates on itsown frequency, it can beseen that the compound fork of Figure 4 when made to vibrate generates four fundamental'frequencies i. e. those corresponding to the forks 4, 2, Band 23' respectively. If a-compoundfork generating 5 fundamentals is to be" designed; this can be made by replacinga part ofthe tine 4' of the fork 4 and'by' fixingto the remainin'gtlnepart another-smaller standard fork. In a general' way a compound fork generating" funds.- mentals=comprises n+l tines;

The" compound forkaccording to Figure 5* is similar to that-shown in Figure 4 and differs onlyfrom the latter in that all its tinesare parallel to each other and bent at'rightangles overthe tail portioni.

The fundamental principle lies in the fact that each fork except the firstone is constituted by'a complex-fork supporting on one ofits legs acomplex or standard fork.

The various legs of the ensemble can be welded, brazed, or made of one slngle?piec'e.

The Said plane; whereas the tines 4' and 4" which constitute the constituent fork 4 lies in a different plane.

The vibrations of the compound forks according to the Figures 2 to do not only generate the fundamentals of the several forks but also the higher partials which are neglected as being remote from the fundamentals by approximately 3 octaves. If the ratio of these frequencies of the upper partials 2, 3, 4 to the frequency of the fundamental is to be increased, the tines of the forks may be provided either with notches 1, 8, '9 and I!) (Fig. 6), or with hollowed portions H and [2 (Fig. 7) or with weights such as l3 l4, |5and l-B infEig. 8.

The legs of a complex fork can perfectly be calibrated so that the frequencies produced are for instance the 1st, 2nd, 3rd, 4th, 5th and 6th harmonics of a given fundamental.

The complex fork can thus replace strings in certain musical instruments such as the piano, harpsichord, harp, zither, etc.

, It can replace with advantage the rods and forks used in certain musical instruments such as the dulcitone, typophone, celesta, Xylophone, glas'schord, etc.

Besides those-forks can be used for all cases for which those various instruments instead of generating sounds through the channel of a sound-board would produce them through any amplifying system (for instance: a fork vibrating near a polarized coil transmitting induced voltages to the terminals of a pick-up in a radio set, the final source of sounds being a loud speaker instead of the sound-board).

- In this order of ideas the complex fork is quite advisable for constituting the vibrating elements of certain types of electric chimes with a loud speaker.

Figs. 9 to 11 show a new device for damping the forks described above. According to Fig. 9 which is a section of Figure 3 along lines IXIX each of the tines 6", 2", 4", 4' of for example the compound fork of Figure 3 is in contact with a small strip of felt l8, l8, I8", 18 suspended from a common support 20 by means of strip of cloth l9, I9, l9, l9"' which acts as a flexible articulation, the said common support being slidable in order to permit the damper to be put in service or to be put out of action.

According to Fig. 10 which shows two tines corresponding to any one of the partial forks of Figures 2 to 8 a lump of damping material 2| (felt, Wool, etc.) is inserted between the legs 2", 4", of the fork while according to Fig. 11 the damper consists of helical coils 22, 22' made of wool or any other material wound and fixed upon legs 2", 4" of the fork at appropriatelychosen points.

Naturally the invention of the complex fork is in no way limited to the embodiments shown and described and which were chosen only by way of example.

What I claim is:

1. A vibratory complex fork having a supporting reed and two oppositely vibrating tines secured to said reed, in which one of said tines comprises a tuning fork, a first tail portion carrying said tuning fork, a vibratory tine fixed to said first tail portion and a second tail portion fixed to said supporting reed.

2. A vibratory complex fork having a supporting reed and two opposed vibratable tines secured to said reed, in which at least one tuning fork is fixed to one of said tines. I

3. A vibratory complex fork having a supporting reed and two opposed vibratable tines secured to said reed, in which at least one tuning fork is secured to one of said tines, said one tuning fork being located in a plane different from that determined by the other tine and the supporting reed.

4. A vibratory complex fork having a supporting reed and two opposed vibratable tines secured to said reed, in which at least one tuning fork is secured to one of said tines, said one tuning fork being located in the plane determined by the other tine and the supporting reed.

5. A vibratory complex fork having a supporting reed and two opposed vibratable tines secured to said reed, in which one of said tines carries at least one tuning fork having two opposed vibratable legs, and in which the other tine and at least one of said legs are provided with means for eliminating undesirable harmonics of the fundamentals produced by the vibrations.

6. A vibratory complex fork according to claim 5, wherein said harmonic eliminating means includes notches on said other tine and said one leg, said notches being located near the fixed ends thereof.

7. A vibratory complex fork according to claim 5, wherein said harmonic eliminating means includes masses fixed to the free ends of said other tine and of said one leg.

8. A vibratory complex fork having a supporting reed and a first fork including two opposed vibratable members secured to said reed, in which one of said members carries at least a second tuning fork having two opposed vibratable members and in which the other member of said first fork and at least one of the members of said second fork are provided with damping meansj 9. A vibratory complex fork according to claim 8, in which said damping means includes a strip of a damping material freely bearing On its associated member.

10. A vibratory complex fork according to claim 8, in which the damping means is formed by a lump of damping material inserted between the said other member of said first fork and said one member of said second fork.

11. A vibratory complex fork according to claim 8, in which the damping means is constituted by a helical winding of a damping material on its associated member.

12. A vibratory complex fork having a supporting reed and two opposed vibratable tines secured to said reed in which one of said tines has a reduced length, and a succession of tuning forks supported on the free end of said one tine. each fork in said succession except the last having a tine or reduced length carrying the next fork in said succession.

13. A vibratory complex fork comprising a succession of progressively shorter tuning forks having each two opposed vibratable tines, all but the shortest of said forks having one tine shorter than the other and in which all but the longest of said tuning forks is carried by the shorter tine of the next longer tuning fork.

14. A vibratory complex fork as defined in claim 12, in which each of said forks but the longest extends over the free end of the longer tine of the next longer fork.

15. A vibratory complex fork as defined in claim 12, in which at least one tuning fork of said succession is located in a plane different from that determined by the other tuning forks and the supporting reed.

16. A vibratory complex fork as defined in claim 12. in which all of the tuning forks of said succession and the supporting reed are located in a same plane.

REMY JOSEPH MARIE CECILE LANGLOYS.

REFERENCES CITED The following references are of record in the 10 file of this patent:

Number 6 UNITED STATES PATENTS Name Date Arkins et a1 July 11, 1871 Whitney Apr. 8, 1873 Kitching Oct. 1, 1918 Rusler Dec. 23, 1947 Shonnard. Feb. 14, 1950 Roth- Sept. 12, 1950

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