US2434441A - Device for retarding and for regulating the speed of the flow in accordions and similar musical reed instruments - Google Patents

Description

Jan. 13, 1948. R. SEYBOLD 2,434,441

DEVICE FOR RETARDING AND FOR REGULATING THE SPEED OF THE FLOW IN ACCORDIONS AND SIMILAR MUSICAL REED INSTRUMENTS Filed May 22, 1940 Patented Jan. 13, 1948 DEVICE FOR RETARDING AND FOR REGU LATING THE SPEED OF THE FLOW IN AC-. CORDIONS AND SIMILAR MUSICAL REED INSTRUMENTS Rene Seybold, Strasbourg -Meinau, France Application May 22, 1940, Serial No, 336,566 In France June 13, 1939,

Section 3, Public Law 690, August 8, 1946 Patent expires June 13, 1959 Claims. 1

This invention relates to the art of -making devices for retarding and regulating the speed of the. flow in accordions and similar musical reedinstruments by inserting two or more elastic and rigid compartments communicating through narrow perforations, or pipes and by the aid of which the regulating of the speed of the flow may be secured.

The sound of musical reed-instruments with key-boards, whatever shape and denomination might have been given to these instruments, are produced by the aid of well tuned metallic reeds without head-pieces. These reeds are called free reeds and in contrast to the soft cane-reed stops of the orchestra-instruments are capable of oscillating in their own period. They are brought into oscillation by the difierence of the atmospheric pressure on their respective sides. The air flows in consequence periodically through the openings in which the reeds are fixed, in the direction of the lower pressure.

It is known that the timbre is influenced by all the details of the mechanical fabrication ofthe.

reeds as well as by the fixation of the latter on the opening over which it is fitted up. But both the character of its excitement and its position with respect to the blowing-in current are decisive of. the nature of the formation of the sounds. The excitement of metallic reeds in key-instruments is brought about, in contradistinction to the orchestra-instruments provided with soft cane-reeds, by air produced mechanically, namely by one or more collapsible bellows the dimensions of which are fixed by the wind-consumption of the totality of the tunes.

Two distinct species are known:

In the case of organs as well as in similar musical instruments the sound-producers receive their blast from a blast-engine capable of deliverlng an air-current of unlimited duration, and the tension of which remains constantly uniform. Neither the tension nor the speed of the flow can be influenced by the player; the sound-producers are intonated for a fixed blast, i. e., they are so regulated that they clearly and fully accept and deliver for a fixed speed of the flow.

Now, contrarily to the production of blast in the organ-like instruments, the excitement of the metallic reeds in musical instruments belonging to the class of accordions is brought about by the aid of a gradual increase of the air coming in or flowing out from collapsible quadrangular air bellows. The bellows have neither suction-valves nor discharge-valves; when the bellows are extended, atmospheric air is sucked into the same 2 through the exposed openingsofthe reeds, and the drawn-in air is thereafter expelled through these openings due to the compression of the bellows.

As oftenas the openings are shut or exposed by the key-valves the flow of air through the accordion'receives a more or'less hard blow, i. e., a sudden compression or expansion takes place influencing the volume of the bellows and bringing about the well known hard, hacking sound of the accordion.

In order to make the reed-instruments of the accordion type suitable for performance of serious music, the present invention provides-certaindamming or retarding means, whereby the compression andflow of air is broughtunderthe control of the player. Thus, it is possible to produce a musical tone with all the expressiveness and artistry as is produced by the customary artists instruments namely, string and wind-instruments. As is well known these phenomena are due to the compound vibration which may be produced-on these-instruments.

The accompanyingdrawing-illustrates but does not limit themeansemployed for carrying out the principle ofcompound acoustic control in-the case ofaccordions.

The drawing represents a cross-section-through an accordion.

In the drawing reference characters I, la designate the checks or retarding means for shutting up the open ends of the collapsible bellows 2 thus forming three compartments 3, 4, 4a. Reference characters 5, 5a represent the check-nozzles. 6, 6a are the reed-chambers, 1, 1a represent the openings of the reed-chambers, while 8, 8a designate the frames of the reeds and 9, 9a represent the reeds proper; the key-valves are designated by ID, Illa, the bass-part is represented by H and the soprano-part is designated by It is known that in the case of accordions the bass-part H and the soprano-part shut up both to the air pressure. According to the present invention, on the other hand, two or more compartments are formed instead of a single main compartment. The several compartments differ in that variable pressures are produced in one of the compartments 3 which pressures are brought about by increasing or reducing the volume whereas the other compartments 4, 4a serve for producing the compound sound efiect referred to above.

When the compartment 3 is first extended and then compressed, a compression, corresponding to the applied force, of the air-volume comprised in this compartment takes place at once. A quantity of air corresponding to the cross-section of the check-nozzles 5, 5a flows into these nozzles, but the air current is here retarded or dammed over a certain distance. Thereafter the air fills the compartments 4, 4a and finally enters the reed-chambers 5, 6a.

Now, when the key-valve I exposes the opening 1 the vibration of the reed 9 in the direction of lower pressure takes place; in the compartment 3 or rather in the check-nozzles 5, the escape of the air is then retarded as often as the reed 9 closes the frame of the reed. If the compartment 4 has been given adequate dimensions, a compression-wave is produced therein which enhances the natural vibrations of the reed.

As soon as the pressure is increased in the compart 3 the resistance in the check-nozzles 3 becomes greater, the speed of the flow increases accordingly so that the amplitude of oscillation of the reed undergoes an enlargement equal to the resting-position; in the case of a diminution of the pressure the speed of the air current is reduced in the reverse direction till the tone slowly dies out.

The smaller the set of reeds the more efficient is the retardation. The number of the compartments 4 may therefore be increased in a corresponding manner. Each set of reeds receives the current of a certain number of check-nozzles corresponding to the air current consumed thereby.

What I claim is:

1. An accordion comprising two compartments,

one of said compartments being elastic and the other rigid, and sound producing means in said rigid compartment, said means being adapted to produce musical sounds when air under pressure is admitted to the rigid compartment, a wall separating said two compartments, said wall having perforations to establish communication between said comparments, whereby regulation of the speed of the flow of air is secured, the number of said perforations corresponds in each case to the amount of air consumed, between the elastic compartment and the rigid compartment, the air compressed in the elastic compartment is driven through said perforations and delayed for a certain length before it flows into the rigid compartment.

2. The device claimed in claim 1, comprising a second wall to form three compartments, said second wall having perforations whereby communication between said three compartments is established, and said elastic compartment is formed by collapsible bellows, and the remaining two compartments forming the bass part and the soprano part, respectively, said two walls being disposed between the bass-parts, the bellows and the soprano-parts.

3. The device claimed in claim 1, in which nozzles or pipes extend through said perforations, said nozzles or pipes having an unequal width.

4. The device claimed in claim 1, in which said sound producing means are formed by reeds, said reeds being subdivided and disposed in sub-compartments wherein the volume of the tone of the reeds is several times divided each sub-compartment being provided with perforations, a, number of nozzles disposed in said perforations, the number of said nozzles corresponding to the capacity of each compartment.

5. The device claimed in claim 1, comprising a plurality of stop-valves in said rigid compartment adapted to selectively close certain of said perforations according to the consumption of air and the desired volume of the tone.

RENE SEYBOLD.

UNITED STATES PATENTS Number Name Date 1,139,010 Anderson May 11, 1915 FOREIGN PATENTS Number Country Date 31,010 Germany Apr. 18, 1885

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