US2145530A - Electric tremulant attachment for accordions - Google Patents

Description

Jan. 31, 1939. v L H 2,145,530

ELECTRIC TREMULANT ATTACHMENT FOR ACGORDIONS Filed Aug. 9, 1957 2 Sheets-Sheet 1 amen V1304,

Zeste 7" 5.2222572 v/ Jan. 31, 1939. I L EfRusH 2,145,530

ELECTRIC TREMULANT ATTACHMENT FOR ACCORDIONS Filed Aug. 9, 1937 2 Sheets-Sheet 2 70 n W A Patented Jan. 31, 1939 UNITED STATES PATENT OFFICE Lester E. Rush, Great Falls, Mont.

Application August 9,

6 Claims.

This invention relates to an electric tremulant attachment for accordions which will automatigally cause the notes to sound with a tremulous one.

It is an object of the invention to provide an attachment of the above-mentioned character which may be installed in the conventional accordion without material alterations and which embodies means for eliminating the tremulous effect at the will of the operator.

A further object of the invention is to provide an attachment of the above-mentioned character which is simple and durable in construction, reliable and efiicient in operation and inexpensive to manufacture.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Fig. 1 is an end elevation of an accordion, partly in section, with the attachment installed therein,

Fig. 2 is a perspective View of the accordion and attachment in separate relation,

Fig. 3 is a side elevation of the attachment, showing the motor mounted within the frame of the attachment,

Fig. 4 is a side elevation of the opposite side of the attachment with the motor mounted outside the frame,

Fig. 5 is a section taken on line 55 of Fig. 4,

Fig. 6 is a detail perspective view of the switch mechanism for operating the free port valves,

Fig. 7 is a perspective view of the tremulant valve, and,

Fig. 8 is .a fragmentary longitudinal section of the tremulant valve.

In the drawings, wherein for the purpose of illustration I have shown a preferred embodiment of my invention, the numeral 5 denotes a conventional accordion in its entirety having the usual bellows 6, with compartments 1 and 8 on opposite sides thereof containing the bass and treble reeds respectively.

Referring more particularly to my invention, the attachment consists of a partition 9 surrounded by a frame ID adapted to be installed between the bellows 6 and treble compartment 8 of the accordion. The partition 9 is composed of two separable boards and a bore H is formed between the partition boards to extend longitudinally of the partition adjacent its lower edge, the

1937, Serial No. 158,250

bore being provided with opposed openings l2, at spaced intervals throughout its length, providing air passages through the partition. A tubular valve casing I3 is fixed within the bore l I having a series of spaced openings I 4 corresponding to 5 the openings l2 and adapted to register therewith. A rotary valve of tubular construction is mounted to revolve within the casing 13 having opposed openings H5 at spaced intervals adapted to register with the openings l4 upon 10 rotation of the valve and disposed within the valve between the openings [6 are plugs I! to prevent whistling and air leakage. The solid portion of the valve which passes the openings I4 is slightly narrower in width than the openings 15 I4, so that at no time is the opening completely closed. The rotary valve extends beyond the ends of the casing I3 and is secured therein by means of a jam cap l8 aflixed to the end of the valve by a set screw Ill. The opposite end of the rotary valve carries a gear wheel 20 which meshes with the worm 2| formed on the shaft 22 of the electric motor 23, the free end of the motor shaft being journaled in the bearing clamp 24. The motor 23 is mounted on the partition either 25 beyond the frame H], as shown in Fig. 2, or may be mounted on the partition within the frame, as shown in Fig. 3. The motor is connected to a suitable source of electric current by the wires 25 and interposed in the circuit of the motor is a rheosta-t 26 by means of which the speed of the motor is regulated.

A series of spaced free air ports 21 extend through the partition 9 adjacent its upper edge which are normally closed by valve plates 28 covered with a lining of soft leather 29. The valve plates are connected to arms 30 extending from the shaft 3| journaled in the bearing brackets 32 attached to the partition. A series of U-shaped loops 33 extend from the shaft 3| at spaced intervals, the end loops being engaged by the leaf springs 34 affixed to the partition, which hold the valve plates in closed position. The intermediate loop is disposed in the path of movement of the cam face 35 of the disk wheel 36 mounted on one end of the shaft 31 which is journaled in the upper side member of the frame ID. A crank arm 38 is attached to the opposite end of the shaft 31 which is connected by means of the rod 39 to the slide lever 40 slidably mounted in the outer face of the upper side member of the frame I0 and by moving the slide lever the wheel 36 is turned to bring the cam face 35 into engagement with the intermediate loop 33 on the shaft 3|, thereby rocking the shaft to swing the valve plates 26 to an open position.

In operation, the tremulant attachment is easily installed in the conventional accordion by separating the treble compartment from the be lows and inserting the frame [0. Upon starting the electric motor 23 the rotary valve I5 is revolved at a pre-determined speed causing a pulsating current of air to pass through the openings [2 when the bellows are actuated and thus cause the treble reeds to sound with a tremulous tone. When it is desired to eliminate the tremulant effect, the slide lever 40 is moved to turn the Wheel 36 so as to rock the shaft 3| to open the valve plates 28 and allow a free flow of air through the ports 21 which changes the tone of the reeds from a tremolo to a plain tone without having to stop the motor. Thus, itis seen the tremulant effect may be brought into operation or eliminated at the will of the player.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same and that certain changes in the shape, size and arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a central longitudinal bore provided with opposed openings at spaced intervals, a rotary valve mounted to revolve in the bore of said partition having transverse passages therethrough at spaced intervals, said passages being of a size to permit communication between the opposite openings at all times and means for revolving said valve whereby the volume of air passing through said openings is varied.

2. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a series of spaced passages therethrough, a rotary valve intersecting the passages of said partition and having transverse passages therethrough, said passages being of a size to permit communication between the passages of said partition and valve at all times and means for rotating said rotary valve to vary the volume of' air passing through said passages.

3. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a series of spaced passages therethrough, a rotary valve intersecting the passages of said partition and having transverse passages, said passages being of a size to permit communication between the passages of said partition and valve at all times, an electric motor mounted on said partition and gearing driven by said motor for driving said rotary valve to vary the volume of air passing through said passages. 1

4. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a series of spaced passages therethrough, a rotary valve intersecting the passages of said partition and having transverse passages therethrough, said passages being of a size to permit communication between the passages of said partition and valve at all times, means for revolving said valve to vary the volume of air passing through said passages, a series of free ports through said partition, valve plates normally closing said ports, and manual means for moving said valve plates to open said ports.

5. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a series of spaced passages therethrough, a rotary valve intersecting said passages of the partition and having transverse passages therethrough, said passages being of'a size to permit communication between the passages of said partition and valve at all times, a gear wheel carried by one end of said rotary valve, a motor mounted on said partition, a worm carried by the shaft of said motor and meshing with said gear wheel, a series of free ports through said partition, valve plates normally closing said ports, a shaft connected with said valve plates for swinging the plates to open and close said ports and manually actuated means for rocking said shaft.

6. A tremulant attachment for accordions comprising a partition adapted to be inserted between the bellows and treble reeds of an accordion, said partition having a central longitudinal bore provided with opposed openings at spaced intervals, a rotary valve mounted to revolve in the bore of said partition having transverse passages therethrough, at spaced intervals, for register with the openings, said passages being relatively wider than said openings to permit direct communication between opposed openings at all times and mechanical means for rotating said valve at a predetermined constant speed.

LESTER E. RUSH-

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