US2650515A - Wind supply device for musical instruments - Google Patents

Description

Sept. 1, 1953 .1. ROBOTTI WIND SUPPLY DEVICE FOR MUSICAL INSTRUMENTS Filed Jan. 18, 1951 l l l U I 1 F l-55 m INVENTOR. Jbse M $050]?! I? 7' TUNA/E Y Patented Sept. 1, 1953 UNITED STATES PATENT OFFICE WIND SUPPLY DEVICE FOR MUSICAL INSTRUMENTS 1 Claim. 1

The present invention relates to air operated musical instruments of the piano-accordion type and, more particularly, relates to improvements in a musical instrument such as disclosed in my copending application for United States Letters Patent, Serial Number 165,547, filed June 1, 1950.

In the aforementioned application, there is illustrated and described a piano-accordion type musical instrument comprising, insofar as the present invention pertains thereto, air operated sound producing means, air pressurizing means including a motor and a blower, a pressurized air by-pass port, means for controlling the effective area of the port, a resistance element connected in series with the motor and means for shunting out the resistance element.

It is intended that this instrument is normally played with a comparatively small volume of pressurized air supplied by the blower and, for this purpose, a substantial volume of pressurized air is by-passed and the motor is operated at a relatively low speed to substantially reduce the output of the blower. When crescendo effects or the like are desired, the by-pass port is partially or fully closed and the resistance element is shunted out to enable the motor to operate at a higher speed, whereby a relatively large volume of air is supplied to the sound producing means. In view of the fact that electrical current is normally passing through the resistance element, it has been found that the resistance element frequently is dangerously overheated and may constitute a fire hazard or otherwise may be objectionable, particularly when the instrument is played steadily over a long period of time.

Accordingly, an object of the present invention is to eliminate the foregoing difliculties.

Another object is to provide an improved air flow system for instruments of the character indicated herein.

Another object is to utilize the by-passed air for effecting cooling of the resistance element.

Another object is to provide an improved valve for controlling the fiow of air.

A further object is to provide improved means for operating the valve.

A still further object is to accomplish the foregoing in a simple, practical and economical manner.

Other and further objects will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claim, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

In accordance with the present invention, the foregoing objects are accomplished by providing a musical instrument of the class described which generally comprises air operated sound producing means, air pressurizing means including a motor and an air outlet in communication with the sound producing means, a resistance element electrically connected with the motor, and a conduit for directing air from the outlet across the resistance element to effect cooling thereof. In an illustrative embodiment of the invention about to be described, the air (a portion of which is by-passed while the instrument is played normally with the resistance in the motor circuit to reduce its speed) is directed through the conduit, and a valve is associated with the conduit for controlling the flow of air to vary the volume of sound produced by the instrument. This arrangement is facilitated by positioning the resistance element in a chamber section having an air inlet associated with the conduit and having an air outlet through which the by-passed air is discharged from the instrument.

A preferred embodiment of the invention has been chosen for purposes of illustration and description as is shown in the accompanying drawing, forming a part of the specification, wherein:

Fig. 1 is a front view of an instrument in accordance with the invention, the upper portion thereof being shown in elevation and the lower portion thereof being shown in section.

Fig. 2 is an enlarged sectional view of the lower portion, taken substantially along the line 22 on Fig. 1 with certain elements removed to more clearly illustrate the air by-passing controlling means.

Fig. 3 is a sectional view taken along the line 3-3 on Fig. 2.

Fig. 4 is a sectional view taken along the line 4-4 on Fig. 2.

Fig. 5 is a circuit wiring diagram.

Referring to the drawing in detail and more particularly to Fig. 1 thereof, there is shown a musical instrument of the piano accordion type which generally comprises an upright pedestal H) for housing air pressurizing means including a motor II and a blower l2; and a horizontal cabinet 14 mounted on the pedestal for housing sound producing means, such as reeds and the like (not shown), and having a keyboard and other sound controlling means thereon, generally indicated by the reference numeral l5.

The pedestal I0 is a hollow tubular structure or casing comprising a base portion 16 for supporting the same in upright position; an upper end wall ll formed with an opening it through which pressurized air flows to the inlet of the cabinet l4, and upper and lower partitions 2e and 2 5, respectively, dividing the casing into an upper chamber section 22, a lower chamber section 26., and an intermediate chamber section 25. As shown herein, the motor and the blower are mounted on the upper partition 26 with inlet of the blower in communication with the intermediate chamber section 25 and the outlet of the blower in communication with the upper chamber section 22. The intermediate chamber section is formed with an air inlet opening 2%, and the lower chamber section Ed is formed with a by-passed air outlet 21, the purpose of which will become apparent hereinafter.

As illustrated in Figs. 1 to 4, a conduit Ell, herein shown as a rectangular tube, interconnects the upper and lower chamber sections and extends through the intermediate chamber section. This conduit has a rectangular port or opening 3! adjacent its upper end, which opening constitutes a by-pass air inlet located above the partition 29 and communicating with the upper chamber section. The conduit also has an outlet in registry with an opening formed in the partition 2i to establish communication with the lower chamber section.

In order to vary the volume of air delivered to the sound producing means to produce various effects while playing the instrument, the motor is normally operated at a reduced speed and a relatively large volume of the pressurized air is by-passed through the conduit 3i Provision, however, is made for operating the motor at a high speed and for reducing the volume of air which is by-passed. Such an arrangement preferably comprises one or several resistance elements 32, electrically connected in the motor circuit, and valve means controlling the effective area of the port ii of the conduit.

As shown herein and to accomplish certain of the aforementioned objects of the present invention, the resistance elements 32 are positioned in the lower chamber section 2d. Preferably, the resistance elements 32 are mounted on the underside of the partition 2! and are so arranged with respect to the lower end of the conduit Bil that by-passed air is blown across the same. In the normal playing of the instrument, as pre viously indicated, considerable electrical current flows through the resistance elements which causes heating thereof. However, since a large volume of air is by-passed normally while such heating takes place, a sufiicient volume of air is directed across the resistance elements to cool the same and prevent overheating thereof.

The valve means for controlling the port 3i are shown more particularly in Figs. 2, 3, and 4 and preferably are of the foot operated type. These valve means comprise a valve member or blade 35 slidably mounted in the conduit Sh adjacent the port 3!, a spring 36 "for normally holding the blade in a position to fully unclose the port, a shaft 3'; extending through the pedestal adjacent its base portion, a foot pedal 39 at each end of the shaft and at the exterior of the pedestal, a lever Ml having one end rigidly mounted on the shaft and positioned in the lower chamber section beneath the conduit ill, a rod ll extending through the conduit having one end loosely connected to the other end of the lever and having its other end connected to the blade 35, and a spring 42 for normally biasing the lever in a direction to maintain the shaft in a position to hold the foot pedals upwardly, as shown in full lines (Fig. 2). As noted, these elements are arranged in a compact and convenient manner.

With the foregoing arrangement, the eifective area of the port 3! may be varied to reduce the volume of the air by-passed, as by simply depressing the foot pedals a desired distance, the loudest sound effect of the instrument being produced when the port is fully closed, as by bringing the foot pedals all the way down to the floor or other supporting surface, as shown in broken lines (Fig. 2). The foot pedals 39, the lever M, and the valve blade 35 in this manner are so arranged that a sudden depression of the foot pedal with great force does not subject these elements to any great strain. This is primarily because of the fact that the floor acts as a stop for the foot pedals, as well as for the foot of the operator, whereby the foot comes to rest with the foot pedals and further pressure exerted on the foot pedals has no effect on the valve operating elements.

When the port 3! is fully closed, it is also desirable to cut out the resistance elements 32 to enable the motor to operate at a much higher rate of speed and thereby cause the blower to suddenly produce a large volume of air capable of accomplishing crescendo efiects. To provide for the foregoing, a normally open switch :35 is positioned in the lower chamber section, which switch has an operating element it adapted to be engaged by the lever at when in its lowermost position to close the switch.

In Fig. 5, a wiring circuit diagram is shown which illustrates a pair of parallel connected resistance elements 32 connected in series with the motor l l and a shunt or cut-out conductor connected in parallel with the resistance elements including the switch 5. The circuit, as shown, further includes a variable resistance element, such as a rheostat 47, for adjusting the speed of the motor, and a master switch lil for controlling the energization of the motor circuit.

From the foregoing description, it will be seen that the present invention provides an improved instrument of the piano-accordion type which has a simple, practical and highly advantageous air by-passing circuit for simultaneously controlling sound effects and for effecting cooling of the resistance elements, whereby overheating cannot take place. The valve control means are rugged in construction and are so arranged that damage thereto by heavy foot pressure is prevented. A further advantage is that the air which picks up heat from the resistance elements is discharged from the instrument and does not pass through the reeds or other sound producing means. In this manner hot or extremely dry air is prevented from drying out the reeds and affecting their useful life. The foregoing improvements are provided at relatively small cost and greatly enhance the usefulness of the instrument and its overall economy.

To offer greater stability to the upright pedes tal it, the base portion to thereof is provided with a lateral extension 50 (see Fig. l) at each side thereof, each extension being coupled thereto by a hinge 5! to conserve space when the instrument is placed in its carrying case. The dotted lines in Fig. 1 show the extensions ro tated underneath the base portion it. The extensions 50 also provide stops for the foot pedals 39.

As various changes may be made in the form, construction and arrangements of the parts here in, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matters are to be interpreted as illustrative and not in any limiting sense.

What is claimed is:

In a musical instrument of the class described, a pressurized air supplying device for air operated sound producing means comprising a casing divided into a first, second, and third chamber section, said first section having an air outlet, said second section having an air inlet and said third section having an air outlet; air pressurizing means including a motor and a blower having an air outlet in communication with said first section and having an air inlet in communication With said second section; a resistance element in said third section electrically connected with said motor; a conduit connecting said first and third sections for directing air to said resistance element to effect cooling thereof; a valve for controlling the flow of air through said conduit, said valve including a port in said conduit; a valve member in said conduit for said port; means in said conduit for normally maintaining said valve member in a position to unclose said port; a valve member operating rod in said conduit; means in said third chamber section for operating said rod to effect closing of said port by said valve member; and means at the exterior of said casing for operating said last mentioned means.

JOSEPH ROBOTTI.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 601,318 Fuller Mar. 29, 1898 1,716,651 Moorhouse et al. June 11, 1929 1,760,506 Lodge May 27, 1930 2,064,388 Smellie Dec. 15, 1936 2,087,214 Parsons July 18, 1937 2,185,932 Skinner Jan. 2, 1940 2,289,082 Stevenson July 7, 1942 FOREIGN PATENTS Number Country Date 439,860 Italy Oct. 1, 1948

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