US2601218A

US2601218A - Organ stop switching circuit

Info

Publication number: US2601218A
Application number: US94423A
Authority: US
Inventors: Victor I Zuck
Original assignee: Wurlitzer Co
Current assignee: Wurlitzer Co
Priority date: 1949-05-20
Filing date: 1949-05-20
Publication date: 1952-06-17
Anticipated expiration: 1969-06-17

Description

June 17, 1952 v, l, ZUCK 2,601,218

ORGAN STOP SWITCHING CIRCUIT Filed May 20, 1949 FJ J3 IN V EN TOR.

Patented June 17, 1952 ORGAN STOP SWITCHING CIRCUIT Victor I. Zuck, Kenmore, N. Y., assignor to The Rudolph Wurlitzer Company, North Tonawanda, N. Y., a corporation of Ohio Application May 20, 1949, Serial No. 94,423

9 Claims. 1

This invention relates to electronic organs and more particularly to an electronic organ stop switching means whereby the various tone generators may be selectively rendered effective.

The particular type of organ for which this switching system has been devised utilizes a plurality of Wind driven vibrating metallic reeds as tone generators. A plurality of pickup screws are threadedly mounted in a frame with their free ends spaced a short distance from the vibrating reed. The reeds and associated pickup screws form the plates of a capacitor as explained by Hoschke in his Patent Number 2,014,015 and when the reeds are vibrated as by an air blast the capacitance changes as a function of the vibration. When a potential is applied between the pickup screws and the reeds while the reeds are vibrating, an alternating potential is produced between the reeds and the pickup screws and may be amplied and translated into acoustic vibrations by means such as a loudspeaker. The reeds may be prevoiced by bending or twisting to produce sounds similar to those produced by the various stops of a pipe organ, as described by Hoschke in his aforementioned patent. In the particular form of electronic organ in which this switching system is to be used, the depression of a single key opens a pallet valve to admit air to actuate a plurality of tone generators as is described in detail in my copending application 719,896, filed January 2, 1947, now U. S. Patent No. 2,570,178, granted October 2, 1951. The physical arrangement of the keys, pallets, and tone generators is claimed in the copending application just noted.

It is an object of this invention to provide stop switching means wherein certain of the tone generators actuated may be heard through the application of polarizing potential while others which are actuated remain silent due to a lack of polarizing potential.

Another object of this invention is to provide stop switching means whereby the tonal scope of an electronic organ may be broad even though the organ has but a single keyboard.

A further object is to provide stop switching means whereby a given group of tone generators serves to provide signal voltages for more than a single stop.

Other and further objects and advantages will be apparent from the following description when taken with the accompanying drawing in which:

Fig. 1 is a fragmentary plan view of an electronic organ;

Fig. 2 is a fragmentary sectional view taken through the console of the instrument showing the components that select and generate the organ tones; and

Fig. 3 is a schematic electric wiring diagram of the switching and filtering system, which comprises the most important part of this invention.

Referring now in greater particularity to the figures, the console I of an electronic organ having a single manual is shown in Figs. 1 and 2. A series of keys 2 actuate the tone generators by means to be described shortly in greater particularity and a series of stop tablets 3 are provided, each of which actuates one of the switches illustrated in Fig. 3. The keys are pivotally mounted on a frame 5 by means of pins l. Immediately above the rear extremities of the keys is a wind chest 9 within which are disposed three banks of vibratory prevoiced reeds, the diapason reeds II being mounted horizontally, the ute reeds I3 vertically, and the viole reeds I5, semi-vertically. Mounted adjacent each bank of reeds are a plurality of banks of pickup screws I1, I9 and 2I respectively, corresponding to the three banks of vibrating reeds. Although only one screw is shown associated with each reed, it is contemplated that several screws might be used as taught by Hoschke in the previously mentioned patent. Each bank of screws is electrically connected in parallel as is diagram matically illustrated in Fig. 3, and is connected to the input of an amplifier which is not shown` Immediately below the diapason reeds is a bank of pallet valves 22 which are pivotally mounted on pins 23 and normally held in closed position by springs 25. A coupler pin 21 serves as a coupling medium between each key l and its corresponding pallet valve 2|. The rear end of each key is slotted at 29 and a set screw 3I may adjust the width of the slot so that there will'be no play between the key and the pin. Upon depressing a key 2, the corresponding pallet valve 2l is opened allowing a volume of air to pass over each of the reeds corresponding to that valve through a compartment 33 and an aperture 35 to a wind return trunk 3l. An air compressor which may be of any suitable type is located within the organ housing or console I to provide the required air pressure, but is not shown.

The switching circuit which constitutes an important part of this invention is illustrated in Fig. 3. Polarizing potential is applied to the parallel banks of reeds II, I3 and I5 by means of this switching circuit. The nute reeds are connected in but one parallel treble bank. The diapason and viole reeds, however, are each connected in two banks, bass and treble. A voltage divider 39 is connected across a source of direct current voltage to provide energizing potential for the reeds. Various taps on the voltage divider 39 are selectively connected to a series of single pole double throw switches SW! through SWS, the first four of these switches being bass, corresponding to the viole and diapason bass reeds, and the last iive being treble corresponding to the three banks of treble reeds. Connection between the various switches and corresponding reed banks is made through a B+ filter 3S comprising a resistance-capacitance network to lter out transient disturbances arising from operation of the switches. Two groups of series connected resistors RI through R13 and R14 through RIB also contribute to the reduction of transients and provide circuit isolation.

As an example of the switch connection, the bass diapason stop switch SW l is shown in its energized position to the right. This completes a circuit from the source of potential through a conductor 4I, series resistor Rl, switch SVH, conductor 3, switch SW2, series resistor R2, conductor 45, the B+ iilter and series resistor Rill to the bass diapason reeds. Upon depression of one of the keys in the first two octaves :z-

of the manual, the diapason and viole reeds corresponding to that key will vibrate as air is admitted past the corresponding pallet valve. As the diapason reeds are energized, there will be an output therefrom to the amplifier, but as the Viole reeds are not energized, the vibrating viole reed will not have any output. Ir" it is desired to operate the bass diapason reeds at a lowei` output level, this may be done by moving the dulciana bass switch SW2 tc the right by means of one of the stop tablets This completes a circuit from a lower potential on the voltage divider 35 through a conductor li?, resistor R3, switch SW2, and from there through the path previously described, comprising the resistor R2, conductor 45, the B+ lter and resistor R14 to the bass diapason reeds. As the potential applied in this manner to these reeds is lower than that applied previously, a smaller alternating current potential will be on the pickup screws and the output level will be less. If a ull complement of diapason tones is desired, the switch SW?, may be thrown to the right by one of the stop tablets 3 to energize the diapason reeds. If it is desired to have a lower output level from the diapason treble reeds, the dulciana switch SWE may be thrown to the right by another one of the stop tablets 3 to connect a lower voltage to the reeds in a manner similar to that described with regard to the bass diapason tablets. It is possible by selective operation of the switches SW i through SWS by means of the stop tablets 3 to select any desirable combination of bass and treble stops to obtain a wide range of tonal structure with but a single manual. It is to be noted that upon opening any stop the corresponding reeds are immediately grounded to preclude any possibility of tonal overhang due to slow potential discharge from the capacitors in the B+ iilters. A tremulant which is not shown may be controlled by one of the stop tablets so that ten stop tablets 3 are shown in Fig. l although there are only nine corresponding switches in Fig. 3.

It is `apparent that I have herein provided an electronic organ having a single manual having a plurality of groups of tone generators comprising wind driven vibratory reeds. It is further apparent that the switching circuit presented makes it possible to selectively operate any desirable combination of groups of reeds although a reed from every group is vibrated upon depression of one of the keys in the manual.

Although for illustrative purposes I have shown and described a particular embodiment of my invention, it is to be understood that I do not intend to be limited thereby but only by the spirit and scope of the appended claims.

I claim:

l. In an electronic organ of the type having a plurality of wind driven reeds as tone generators, said reeds arranged in a plurality of banks, electrical cooperative generator means adjacent each oi said reeds and arranged in banks, a manual, a plurality of keys in said manual, means for admitting an air blast simultaneously to a plurality of reeds in diierent banks in response to manipulation of one of said keys, a source of electrical potential, and means includswitching means for selectively applying electrical potential to selected ones of said banks of reeds and associated cooperative generator means to provide a variable output to an electronic amplifier, whereby a plurality of tonal outputs may be produced from but a single manual.

In an electronic organ of the type having a plurality of wind driven reeds as tone generators, said reeds arranged in a plurality of banks, electrical cooperative generator means adjacent each of said reeds and arranged in banks, a manual, a plurality of valves each for selectively admitting an air blast simultaneously to a plurality of reeds in different banks, a plurality oi' keys in said manual, means linking said keys and said valves for rendering each valve operable in response to a key, a source o electric potential, and means including switch means for selectively applying electric potential to selected ones ci said banks of reeds and associated cooperative generator means to provide a variable electrical output from some or all of the reeds actuated by the air blast and the cooperative generator means associated therewith, whereby a plurality of tonal outputs may be produced from but a single manual.

3. In an electronic organ, a plurality of wind driven vibrating reeds, said reeds arranged in groups corresponding to organ stops, electrical cooperative generator `means associated with each of said reeds and arranged in groups, each reed and associated cooperative generator means forming a variable electric capacitor, a manual, a plurality of keys in said manual, means for admitting an air blast simultaneously to corresponding reeds in a plurality of said groups in response to movement of a single key, a source of a plurality of diierent volta-ges, and means including a plurality of stop switches selectively interconnecting said voltage source and a group of the capacitors formed by said vibrating reeds and associated cooperative generator means for selectively applying voltages to selected ones of said groups of reeds and associated cooperative generator means to produce outputs from a desired number of the reeds vibrated by said air blast, whereby a plurality of tonal outputs may be produced from but a single manual.

4. In an electronic organ as defined in claim 3, stop switches having an element connected to ground to ground a reed to prevent tonal overhang when potential is removed from said reed and its associated cooperative generator means by actuating a switch.

5. In an electronic organ, a plurality of wind driven vibrating metallic reeds, said reeds arranged in groups corresponding to organ stops, the reeds of each of said groups electrically connected in parallel in bass and treble sub-groups, electrical cooperative generator means associated with each of said reeds and arranged in groups corresponding to the groups of reeds, each reed and its associated cooperative generator means forming a variable electric capacitor, a manual, a plurality of keys in said manual, means for admitting an air blast to corresponding reeds in a plurality of said groups of reeds in response to movement of a single key, a source of a plurality of different voltages, a plurality of organ stops, and a plurality of Stop switches actuated by said organ stops and selectively interconnecting said voltage source and a group of said vibrating reeds and associated cooperative generator -means for selectively applying voltages to said reeds and cooperative generator means to produce variable electrical outputs from a desired number of the reeds vibrated by said air blast, whereby a plurality of tonal youtputs may be produced from but a single manual.

6. In an electronic organ, a plurality of wind driven vibrating metallic reeds of different tonal outputs, said reeds physically arranged in groups corresponding to organ stops, means electrically connecting the reeds in each of such groups according to the tonal output of said reeds, electrical cooperative generator means associated with each of said reeds and arranged in groups corresponding to the groups of reeds, each reed and its associated cooperative generator means forming a variable electric capacitor, a manual, a plu-rality of keys in said manual, means for admitting an air blast to corresponding reeds in all of said groups in response to movement of a single key, a plurality of organ stop controls, a source of a plurality of diiferent voltages, and a plurality of stop switches actuated by said organ stop controls and interconnecting said voltage source and a group of said vibrating reeds and associated cooperative generator means for selectively applying voltages to selected ones of said groups of reeds and cooperative generator means to render certain of the reeds vibrated by said air blast effective, whereby a plurality of tonal outputs may be produced from a single manual.

'7. In an electronic organ, a plurality of wind driven vibrating reeds, said reeds physically arranged in groups according to the quality of their tonal output, said reeds further `connected electrically in parallel according to their tonal output, electrical cooperative generator means associated with each of said reeds and arranged in groups corresponding` to the groups of reeds, each reed and its associated cooperative generator means forming a variable electrical capacitor, a manual, a plurality ci keys in said manual,

means for admitting an air blast to one reed of each physical group in response to movement of a single key, a plurality of organ stop controls, a source of a plurality of different voltages, and a plurality of stop switches actuated by said organ stop controls, each of said switches connected to said voltage source and at least some of said switches connected in pairs to the electrically parallel reeds and associated cooperative generator means whereby to render selective groups of reeds and cooperative generator means effective and control the output thereof, in order to produce a plurality of tonal outputs from but a single manual.

8. In an electronic organ as vdefined in claim '7, in which the first switch of a pair is connected through the second switch so that the rst switch is rendered inoperative upon actuation of the Isecond. switch.

9. In an electronic organ of the type having a plurality of wind driven lreeds as tone generators, said reeds arranged in a plurality of banks, electrical cooperative generator means vassociated with each of said reeds and arranged in banks corresponding to the groups of reeds, a manual, a plurality of keys in said manual, 4means for admitting an air blast simultaneously to a plurality of reeds in different banks in response to manipulation of one of said keys, takeup means varying a dimension of each of said keys to eliminate lost motion between said keys and said air blast admitting means, a source of electrical potential, and means including switch means for selectively applying electric potential to selected ones of said banks of reeds and associated cooperative generator means to provide a variable electrical output to an electronic amplier, whereby a plurality of tonal outputs may be produced from but a single manual.

VICTOR I. ZUCK.

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

UNITED STATES PATENTS Number Name Date 2,113,347 Ho'schke Apr. 5, 1938 2,300,609 Zuck Nov. 3, 1942 2,318,936 Fisher May 11, 1943