US2595316A - Reed operated musical instrument - Google Patents

Description

y 6, 1952 c. E. WETZLER 2,595,316

REED-OPERATED MUSICAL INSTRUMENT Filed July 13, 1948 CHARLES E. WETZLER INVENTOR.

Patented May 6, 1952 UNITED STATES PATENT OFFICE REED OPERATED MUSICAL INSTRUMENT Charles E. Wetzler, Long Island City, N. Y.

Application July 13, 1948, Serial No. 38,533 2 Claims. (01.84-377) Another object of the invention is a novel and improved harmonica.

For a better understanding of these and other objects and advantages of the invention reference is made to the following description and accompanying drawings forming part of this application.

In the drawings- Fig. 1 is a partially sectional perspective view of a reed-operated musical instrument showing, ingeneral, an embodiment of the invention;

Fig. 2 is a partial, sectional view of one element showing details of one embodiment-of the invention;

Fig. 3, A, B, illustrate, in a more diagrammatic way, other embodiments of the invention.

Fig. 4-is a partially sectional view of another detail of an instrument embodying the inven tion.

Reed operated musical instruments such as harmonicas and the like generally consist of a flat body portion having a series of channels formed in each side thereof to act as air ducts or chambers for the operation of the reeds. The reeds are mounted on slotted plates which are placed on each side of the body portion with each reed in alinement with one of the cham bers. Although it is customary to construct a harmonica with all of the blow reeds on one side of the body and the draw reeds on the other, instruments are also made with both blow and draw reeds mounted on a single plate. In this instance the body part may be provided with chambers only on one side with individual chambers communicating with the blow and draw reeds.

I have found that with the conventional instruments numerous air pockets exist with the result that substantial turbulence and eddy currents are produced which materially reduce the efficiency of the instrument, as for example in instruments having generally rectangular chambers; In conventional instruments therefore,

because of a relatively low efficiency and-large power loss, large volumes of air are required for actuation of the reeds. This greatly limits the loudness range obtainable on the instrument. Under these conditions the reed is frequently forced or overdriven by the air so that instead of operating at its resonant frequency it operates at some slightly lower frequency with a substantial increase in harmonic content. The note thus produced sounds fiat and the increased harmonic content gives the note a distorted and strained tone. Moreover, withthe conventional instrument musical accompaniment is difiicult be.- cause of the sluggish response and lack of sensitivity of the instrument to changes in air pressure. The player rapidly becomes fatigued because of the large volumes of air required and as a result proper interpretation of the music can not be attained.

With my novel and improved chamber construction I have been able to substantially eliminate all air pockets and their attendant power losses and provide a streamlined path for the air to and from the reeds thus matching the physical dimensions of the chamber aerodynamically with the characteristics of the particular reed served by that chamber. In this way the air economy is greatly improved since it is possible to operate the instrument with very much smaller volumes of air and with considerably improved tonal quality and materially increased loudness range. I have attained an improved operation by increasing the velocity of the air stream, in the case of a blow reed for instance, from the mouth of the chamber to the reed with the result that a substantially uniform direct stream of air impinges on and actuates the reed at its normal resonant frequency. The amplitude can then be readily varied throughout a relatively wide range without overdriving the reed and modifying the fundamental frequency or normal harmonic content of the note.

Moreover, by reason of the increase in efliciency of the instrument I have found that it responds almost instantly to very slight air pressures.

As previously mentioned, musical instruments of this type are formed with a plurality of single open ended chambers for the draw and blow reeds. In conventional practice as I know it, the chambers are substantially rectangular in" cross section with one of the side walls formed by the reed plate so that a vibrating reed constitutes part of the chamber wall. The player then either blows or draws on the open end of the chamber, depending on whether the reed is of the blow or draw type, to actuate and vibrate the reed to produce a musical tone.

Fig. 2 illustrates one of my novel and improved chambers formed in the harmonica body Hi. It is provided with tapered side walls l2. In this way air entering the open end of the chamber at a substantially constant pressure, as obtained for instance by the blowing of a player, will increase in velocity during its travel through the tapered part l2. The high velocity air then strikes or impinges on the blow reed l8 and causes it to vibrate. This increased air velocity causes the reed to respond more rapidly-and easily, enabling the player to more accurately control the amplitude of oscillation of the reed with a correspondin improvement in tonal quality by avoidance of overdriving or forcing the reed by larger volumes of air.

In some instances, especially where short chambers are used as in the case of the higher frequency reeds, itmay be desirable to have a relatively large change in area from one end of the chamber to the other.

In Fig. 2 both the side walls l2 and the bottom l3 are tapered toward the closed end M of the chamber so that the cross-sectional area decreases uniformly from the open to the closed end. In Figs-3A and 3B the area of the chamber throughout its length varies at a predetermined rate of change.

Fig. 3A illustrates a harmonica body part 453 having a chamber 50 in which both the walls 5! and the bottom 57! converge inwardly from the mouth at a constantly increasing rate so that the acceleration of the air will be progressively increased as it proceeds through the-chamber. In Fig. 3B I have again shown the body part 40 of a harmonica having curved walls 53 and a curved bottom. part 54. In this embodiment, however, the walls and bottom part have a convex configuration so that the rate of acceleration of the air is greatest at the mouth and decreases as it proceeds through the chamber.

Inthe construction of my harmonica it may be desirable to use combinations of two or more of the new and improved chambers I have illustratedin Figs. 2 and 3 so that the resultant instrument will require substantially uniform air pressure for the reproduction of the various tones.

For instance, it may be desirable to use a chamber as illustrated in Fig. 3B for actuating a very high frequency reed so that a maximum air velocity can be attained in a relatively short length, whereas it may be desirable to use a chamber of the character illustrated in Fig. 2 for a lower frequency reed which is physically longer than a higher frequency reed and therefore enables the use of a longer chamber which will permit the attainment of substantially equivalent air velocities with a smaller degree of convergence from the mouth of the chamber to the inner end thereof.

For the purpose of clearly disclosing some of the features of this invention I have illustrated the chamber in Fig. 3 as havin a substantially rectangular section. I have found, however, that eddy currents and turbulence which increase the friction of an air passage and lower the efficiency of the system can be materially reduced in a harmonica chamber by providing chambers having curved sections and I have illustrated an embodiment thereof in Figs. 1 and 2 inclusive.

With the embodiments or combinations of the embodiments in Figs. 2 and 3. I have found, in

the case of a mouth-operated harmonica, a loudness range from pianissimo to fortissimo can be obtained by the ordinary player not obtainable with conventional harmonicas with which I am familiar. Because of the decrease in both volume and pressure of air required to start the individual reeds to vibrate, the player is able to render more accurate control over the applied air pressure and the reeds can be vibrated in their normal manner to produce a tone of high quality. In conventional harmonicas Where the power losses are high, the operator or player must necessarily produce relatively large volumes of air at high pressure in order to start the reeds to vibrate, and this conditon results in an actual forcing of the reeds so that instead of oscillating attheir true resonant frequencies, will oscillate at difierent fundamental frequencies and produce a large distorted harmonica content. The resultant tone appears to the ear to be out of pitch and the several reeds when forced in this Way go out of pitch non-uniformly.

My invention permits a wide variation in musical interpretation and exploitation not otherwise feasible and enables the employment of faster tempos in harmonica music,

In addition to the new and improved chamber designs described in Figs. 2 and 3, still further improvements in operation can be attained by mountin the reed relative to the chamber so that the resistance to the air flow will be relatively low in comparison to the reactan-ce of the reed. In other words, by the elimination of unnecessary air pockets between the reed and the chamber it is possible to substantially raise the Q of the reed so that the power required to sustain oscillation is substantially decreased. In Fig. 4 I have illustrated an embodiment of this feature in connection with a draw reed of a mouth operated harmonica.

Referring toFig. i, "it represents a harmonica body having a chamber "H therein of the type illustrated in Fig. 2 wherein the bottom wall 12 tapers upwardly toward the rear end of the chamber. Closing the top of the chamber H is the reed plate 74 having a reed 75 mounted on the plate l4 and adapted to vibrate within a slot it. The direction of vibration of the reed is illustrated by the arrow (2 and the extent of such vibration in a downward direction is indicated-by the broken outline of the reed.

I have been able to further improve the eniciency of harmonicas by proportioning the chamber relative to the reed so that air pockets are substantially eliminated. This greatly decreases turbulence and eddy currents that in effect reduce the Q or the efficiency of the instrument. I have accomplished this by terminating the chamber II at a point in front of the inner end of the reed slot It and making the clearance ll between the reed I5 and the upper face Bl of the body 18 just large enough to accommodate the swing of the reed [5 when it is vibrated. With this structure I am able to obtain a maximum conversion of the energy of the moving column of air into sound energy.

. In Fig. 4 I have illustrated a chamber H in the body part it! having converging walls l3;

In Fig. 2 I have illustrated m new and improved method of improving the Q or the efficiency of a system having a musical reed such as a blow reed in a mouth-operated harmonica having upper and lower sections.

In Fig. 2 I have denoted the body part of the harmonica by the numeral ID having upper and lower chambers II and II a. For the purposes of this description I have illustrated but a single reed plate I 5 having a blow reed I8 mounted therein for vibration within the slot I6. In conventional practice as I know it, the inner wall II, of the chamber II is usually terminated at a point beyond the free end of the reed I8 so that the air pocket would be formed between the rear end of the chamber and the upper plate, I5. Moreover, in conventional practice the chambers are made substantially rectangular in cross-section and the relatively sharp corners produced additional eddy currents and other losses. With my invention I terminate the rear wall I! of the chamber I I substantially in line with the end of the slot I6 so that all of the air entering the mouth of the chamber will be directed upwardly at the reed and be converted into sound energy. Moreover, the particular chamber II is provided with a curved rear wall II to provide a smooth path for the air.

Referring to Fig. 1 showing a single plate harmonica embodying my invention, IIO denotes the harmonica body having a reed plate H2 and a reed plate cover H4. The body part III} is provided with a plurality of blow reed chambers I I6 and interposed draw reed chambers II8. These blow and draw reed chambers embody the new and improved designs which I have illustrated in Figs. 2 to 4 inclusive. Each successive pair of blow and draw reed chambers H6 and H8 respectively is arranged to terminate in a single opening or chamber mouth I since in the operation of the harmonica draw and blow reeds are obviously not operated simultaneously. The reed plate isconstructed to conform with the chambers in the body I III; that is, the blow reeds I22 and the draw reeds I24 are mounted alternately to cooperate with their respective chambers in the body H0. The cover plate H4 in this particular embodiment is generally streamlined and tapering inwardl toward the reeds.

In certain instances my new and improved harmonica may be provided with chambers having a curved rear wall substantially as illustrated at I 4 in Fig. 2. This feature obviously may be embodied in any of the improved chambers shown. Moreover, although I have shown individual upper and lower chambers for two plate harmonicas certain advantages of my invention may also be realized b using a single chamber for opposing upper and lower reeds. In this instance, the side and end walls of the chambers are shaped according to the invention and the chambers are completed by closing one side of the chamber with a plate having a draw reed mounted thereon and closing the other side of the chamber with a blow reed mounted thereon.

From the foregoing description of my invention it is clear that a reed operated musical instrument embodying my invention provides in effect a complete streamlined path for the air from the point of entrance to the point of exit from the chambers. By reducing turbulence in the air stream and the elimination of air pockets to produce the smooth flow of the air through the chambers, the ease of operation and rapidity of response of the instrument are improved. The tonal quality is also improved and the range of loudness and tempos are substantially increased. Moreover, by means of tapering the chambers, as I have described, I can materially increase the Velocity of the air striking the reed and obtain a more efiicient conversion of air pressure to sound energy and more uniform operation of the instrument over the entire tonal range. Moreover, I have found that instruments constructed in accordance with my invention will stay in tune for a longer period of time because, among other reasons, the reeds are not forced but are free to vibrate in their natural periods. The overall response of the instrument is more uniform, sensitive, and easily controlled. All these and other advantages combine to greatly improve the rendition of musical compositions.

I claim:

l. A reed operated musical instrument, comprising a body having pairs of coordinated blow and draw chambers open at its front, reeds mounted each in a slot to swing therein and to cooperate with one of said chambers, the reed associated with a blow chamber mounted with its free end toward the rear of the body and the reed associated with a draw chamber mounted with its free end toward the front of the body, the blow chamber of each pair being longer than the draw chamber, said chambers tapering in cross section inwardly from the front edge so as to cause a variation of air velocity in the particular chamber and a maximum velocity substantially at the swinging free end of the particular reed, the length and the variation of cross section of each individual chamber being aerodynamically matched with the characteristics of the particular reed served by the respective chamber.

2. A reed operated musical instrument as specified in claim 1, the variation of cross section in an individual chamber being not uniform along its length, the rate of variation being aerodynamically matched with the characteristics of the particular reed associated with the respective chamber.

CHARLES E. WE'IZLER.

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

UNITED STATES PATENTS Number Name Date 59,027 Ingalls Oct. 23, 1866 173,652 Lightsinger Feb. 15, 1876 592,850 Weiss Nov. 2, 1897 611,237 Curtis Sept. 2'7, 1898 653,451 Hohner July 10, 1900 1,009,904 Hohner Nov. 28, 1911' 2,000,408 Minevitch May '7, 1935 2,232,238 Jacomini Feb. 18, 1941 2,340,333 Magnus Feb. 1, 1944 FOREIGN PATENTS Number Country Date 530,803 Great Britain Dec. 20, 1940 399,194 Germany July 28, 1924 352,163 Germany of 1922

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