US3266592A - Variable speed multi-channel pulsato rotor - Google Patents

Description

Aug. 16, 1966 D. J. LESLIE 3,266,592

VARIABLE SPEED MULTI-GHANNEL PULSATO ROTOR Filed on. 22, 1965 5 Sheets-Sheet 1 4 39 33 Go 3a 1/ I 40 flrroervsys.

Aug. 16, 1966 D. J. LESLIE VARIABLE SPEED MULTI-CHANNEL PULSATO ROTOR Filed 001.. 22, 1965 5 Sheets-Sheet 2 ammo/v POWER ZINE mfihw @4 Z Z m m s/aA/AL SOURCE 6, 1966 D. J. LESLIE 3,266,592

VARIABLE SPEED MUL'I'I-CHANNEL PULSATO ROTOR Filed Oct. 22, 1965 5 Sheets-Sheet 5 V SIG/VAL I0! I08 I09 I I04 invention. in the drawings accompanying and forming part of the United States Patent 3,266,592 VARIABLE SPEED MULTI-CHANNEL PULSATO ROTOR Donald J. Leslie, Altadena, Calif. Electro Music, P.(). Box 2267B) Filed Oct. 22, 1965, Ser. No. 502,121 9 Claims. (Cl. 181-27) This invention relates to acoustic apparatus for producing pulsato, and of a type shown and described in by prior Patent No. 2,489,653. In this apparatus, rotary sound channels are provided that produce a sound radiation pattern that recurs at a rate required to produce the characteristic pulsato effect. The requisite rate of recurrence is about to 8 cycles per second.

If a single sound channel is rotated, then the required angular velocity is about 400 cycles per minute. This imparts a substantial peripheral velocity to the opening of the sound channel, and a correspondingly large frequency deviation. If the speed is reduced to half, then the fre- "quency deviation is likewise reduced; the rate of cyclic recurrence of the sound radiation pattern is also reduced to about 3 or 4 cycles per second, and the characteristic pulsato is lost. In order to restore the pulsato effect, two sound channels supplied by the same acoustic or electrical source must be used in 180 spacial relationship about the rotational axis.

The organist at times desires a full rich pulsato of the type obtained by rotating a single channel at 400 cycles per minute, and at other times desires a muted pulsato such as obtained by rotating two channels at 200 cycles, or three channels at about 133 cycles, etc. For example, a full pulsato may be appropriate for use with flute, tibia and stopped diapason tones; but only a lesser frequency deviation may be appropriate for string and reed tones.

The primary object of this invention is to provide a single pulsato apparatus capable of producing these various types of pulsato. Another object of this invention is to provide pulsato apparatus of this character in which a number of rotary sound channels are provided on a common support, and wherein a speed change is automatically accompanied by a change in the operative number of sound channels, thus ensuring that the rate of recurrence of the sound radiation pattern (as distinguished from the rate of rotation) is maintained in order to produce the trically, and slip rings .are used in order to conduct the electrical signals to the rotary apparatus. In the latter case, the number of control leads increases, and more complicated slip ring structures appear necessary. Another object of this invention is to provide a system of this character in which the electrical or acoustic switching is accomplished automatically within the framework of the rotary apparatus, all in response to a change in speed of the rotary apparatus. For this purpose, centrifugal devices are carried with the rotary apparatus for operating the acoustic or electrical switches.

This invention possesses many other advantages, and

' has other objects which may be made more clearly apparent from a consideration of several embodiments of the For this purpose, there are shown a few forms present specification. These forms will now be described Patented August 16, 1966 ice in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since thescope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevational view of rotary pulsato apparatus incorporating the present invention;

FIG. 2 is a top plan view of a portion of the apparatus shown in FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view taken along the plane corresponding to line 3--3 of FIG. 2;

FIG. 4 is a top plan view generally similar to FIG. 2, and diagrammatically illustrating a modified form of the present invention;

FIG. 5 is a fragmentary sectional view taken along the ofifset plane corresponding to line 55 of FIG. 4;

FIG. 6 is a diagrammatic view illustrating a modified form of the present invention;

FIG. 7 is a circuit diagram illustrating an alternate switching arrangement for use in the system shown in FIG. 6;

FIG. 8 is a diagrammatic view of a pulsato rotor incorporating modified form of the present invention;

FIG. 9 is a circuit diagram of the relay power circuit; and

FIG. 10 is a circuit diagram of the relay control circuit.

In FIG. 1 there is illustrated a fragmentary part of a cabinet 10. An interior support or partition 11, mounts a driver or transducer 12 designed to convert the electrical organ signal into sound. In the present instance the driver 12 is suspended from a plate 13 that overlies an aperture 14 in the partition 11. A horn 15 provides sound channels registering with the transducer.

A pulley bracket 16 secured to the horn 15 serves as its support, and is mounted for rotation about the axis of the driver 12 by the aid of bearing 17.

The pulley bracket 16 has a through opening 18 that registers with the output of the driver 12. The horn 15 has two sound channels 19 and 20 radiating from a common throat 21 that registers with the opening 18 of the pulley bracket 16. The outer openings of the channels are spaced from the axis of rotation so as to produce orbital motion thereof.

An acoustic switch for closing and opening the channel 20 is provided. This switch is in the form of .a closure plate 22, movable from full line closed position illustrated in FIG. 3 to the phantom line open position while the channel 19 remains in communication with the throat.

ing apertures in the sides of the horn.

Rotation of the shafts 23 and 24 in a clockwise direction as viewed in FIG. 3 causes the valve 22 to be positioned across the channel 20 adjacent to the throat 21. This movement of the closure is limited by an interior shoulder 25. Upon movement of the shaft in the opposite angular direction, thevalve 22 moves into a shallow recess 26 in the upper portion of the horn, thus fully opening the channel 20.

In order to move the valve, a linkage structure is provided. The linkage comprises a crank 27 that includes two arms 28 and 29 fixed respectively to the shafts 23 and 24, and a connecting bar or yoke 30. The arms 28 and 29 extend along the sides of the horn, and the bar 30 extends across the top. The arms 28 and 29 lie in a plane offset approximately from the valve 22. The crank 27 is thus freely reciprocable over the top of the horn as the closure moves between its limited positions. A tension spring 31 normally urges the crank 27 in a counterclockwise direction as viewed in FIG. 3 in order to open the channel 20. Thus one end of the spring 31 is afiixed to the connecting bar 30 and its other end to an apertured boss 32 formed on the horn 15. A Weight assembly 33 counterbalances the spring 31 and closes the channel before the horn reaches a speed of 400 revolutions per minute.

The weight assembly includes a rocker 34 pivoted on the horn beneath the channel 20 for movement about an axis parallel to that of the closure 22. The rocker 34 has arms 35 and 36 that extend upwardly along opposite sides of the horn and a connecting portion 37. A rod 38 projecting upwardly from the connecting portion 37 adjust-ablymounts a weight 39, as by a set screw 40. The rocker 34 is connected to the crank 27 by the aid of a link 41, pivoted at its ends respectively to the rod 38 and the connecting bar 30. Accordingly centrifugal force urges the rocker 34 in a clockwise direction as viewed in FIG. 3 to close the valve 22. When the horn is rotated at low speeds, corresponding substantially to about 200 cycles per second, the spring 31 overpowers the centrifugal force of the weight 39 and causes the channel to be opened.

At low speed, both channels are operative, causing a recurrence in the sound radiation pattern at the rate of approximately 400 cycles per second. However, when the horn 15 is rotated at about 400 cycle per second, there is but one operative sound channel 19, and again the rate of recurrence of the sound radiation pattern is 400 cycles per second. In both instances the characteristic pulsato rate is achieved.

In order to rotate the horn 15, the motor 42 is provided (-FIG. 1) that may be mounted upon the inside of the cabinet wall10. The motor 42 has a pulley 43 connected to the pulley bracket 16 by the aid of a fiexible belt 44. The motor 42 may be a two speed motor controlled by a simple double throw switch, notshown.

In the form illustrated in FIGS. 4 and 5 a still more versatile pulsato apparatus is provided. In this instance four sound channels 51, 52, 53, and 54 are provided that are equiangularly spaced about the axis of the device. As in the previous form, these sound channels all communicate with a common throat 55 that registers with the non-rotary transducer. When the horn 50 is rotated at 100 r.p.m., all four channels 51, 52, 53, and 54 are open. When the horn is rotated at 200 r.p.m. two opposite channels 52 and 53 are closed, whereby only the diametrically disposed channels 51 and 54 operate. When the horn 50 is rotated at 400 revolutions per minute the channels 52, 53 and 54 are closed, and only the channel 51 is operative. In all three instances the characteristic recurrence rate of the sound radiation pattern is about 400 cycle per minute. Yet the intensity of pulsato or frequency deviation is substantially changed.

In order to close the channels 52, 53, and 54 centrifugal devices are provided for each channel, substantially in accordance with the form illustrated in the FIGS. 1 to 3.

The only essential difference is that the weights for the channels 52 and 53 are substantially increased whereby closure is effected before the horn reaches a speed of approximately 200 cycles per second. Optionally, adjustment could be made in the position of the weights or in the spring constants. It will also be understood that the common linkage could be provided for operating the valves for both channels 52 and 53.

Before the horn reaches a rotational speed of 200 7, cycles per second the valves for the channels 52 and 53 close in response to the centrifugal force of the Weight or weights, the valve for the channel 54 remaining open. Before the horn reaches the rotational rate of 400 rpm. the valve for the sound channel 54 also closes. Suitable adjustable speed motive means may be provided for the horn 50.

In the form illustrated in FIG. 6 a pulsato rotor 60 is illustrated but in this instance mounts to speakers structures 61 and 62 at diametrically opposite positons thereof. Since the electrical-acoustic transducers associated with the speakers 61 and 62 rotate with the drum a slip ring assembly 63 is necessary in order to conduct the organ signal to the speakers from external leads.

The drum 60 is operated by a two speed motor 64 shown as having three leads 65, 66 and 67. The high speed may be about twice low speed, and by way of example, 380 revolutions per minute. The lead 65 cooperates with one element 68 of a connector cooperable with a power source. The other leads 66 and 67 respectively connect to contact 69 and 70 of a relay structure 71. The relay structure 71 includes an arm 72 connected to the other element 69' of the power connector. The arm 72 is engageable alternately with the contact 69 and the contact 70 upon energization or de-energization of a relay coil 73. Thus upon operation of the relay coil 73, a circuit is effected to the motor by the aid of leads 65 and 66, and upon de-energization of the relay coil 73, a connection is effected to the motor by the aid leads 67 and 65. These alternate connections provide fast and slow operation by well known means. a

The relay 71 also has contacts 74 and 75 cooperable with an arm 76 for determining operation of either one or both of the speakers 61 and 62, all in accordance with the fast or slow operation of the motor 64. The contact 74 connects via a brush 77 and one element 78 of the slip ring assembly 63 to one side of the speaker 62. The other contact 75 connects with one element 79 of a connector to which the organ signal is applied. The arm 76 connects to a brush 80 and through a second element 81 of the slip ring assembly 63 to one side of the speaker 61. The connector element 79 cooperable with the signal source also cooperates via a brush 82 and slip ring element 83 with the other side of both speakers 61 and 62. A

lead 84 joins the other element 85 of the connector to the brush 77 and the relay contact 74.

When the relay coil 73 is tie-energized and the motor 64 thus operated at slow speed, both speakers 61 and 62 are connected to the organ output by the aid of connector elements '79 and 85. The circuit for the speaker 62 may be traced as follows: connector element 85, lead 84, brush 77, slip ring assembly element 78, speaker 62, lead 86, slip ring element 83, brush 82 and connector element 79. A circuit for speaker 61 may be traced from connector element 85, lead 84, relay contact 74,

- arm 76, brush 80, slip ring element 81, speaker 61, lead 86, slip ring element 83, brush 82 to the connector 79. When the relay coil 73 is energized and the motor operated at fast speed, the speaker 61 is removed from cir cuit and furthermore short-circuited. Thus the circuit for the speaker 62 remains as before, independent of the relay contacts 74 and 75 and arm 76. However, the previous circuit traced for the speaker 61 via contact 74 is now interrupted, and instead the speaker 61 is shortcircuited as follows: relay contact 75, arm 76, brush 80, element 81, speaker 61, lead '86, element 83, brush 82 back to the relay contact 75. By short-circuiting the speaker 61, currents induced in its coil damp sympathetic vibrations. Accordingly, no sound issues from the speaker so short-circuited.

The system of FIG. 6 operates to achieve a recurrence rate of the sound radiation pattern that is the same whether the drum is rotated at low or high speed.

In the form of the invention illustrated in FIG. 7, a

switch assembly is carried within the rotary drum. Only two slip ring elements 103 and 104 are provided for conducting the signal from the organ output. The slip ring elements 103 and 104 respectively cooperate with leads 105 and 106 across which the speaker 101 is directly connected. Thus the speaker 101 is continuously energized independently ofthe speed of operation of the drum. The speaker 102, however, is connected across the leads 105 and 106 only when the drum is operated at low speeds.

Thus the switch 101 includes opposite contacts 107 and 108 and switch arm 109 moved by a centrifugal weight 110. In the full line position corresponding to low speed, the cont-act 107 is engaged. This completes the circuit for the speaker 102 as follows: lead 105, contact 107, switch arm 109, lead 111 to one side of the speaker 102, lead weight 110 causes the switch arm 109 to move to the phantom line position and to engage the contact 108. In this position the leads 111 and 112 are connected together and speaker 102 accordingly is short-circuited.

In the form of the invention illustrated in FIG. 6, two slip ring assemblies, such as shown in my prior Patent No. 3,014,192 may be provided, one at the top of the rotary apparatus and another at the bottom. Each assembly includes two slip ring elements. Only three of the four available slip ring elements need be used. In the form illustrated in FIG. '7, only a single two element slip ring assembly is necessary.

In the form illustrated in FIG. 8, drum 150 in this instance mounts six speakers 1, 2, 3, 4, 5, and 6, all equiangularly spaced about the axis of the drum. This rotary assembly is designed to operate at any one of four speeds: 66 revolutions per minute with all six speakers connected to the source; 133 revolutions per minute with only three equiangularly spaced speakers connected to the source; 200 revolutions per minute with only two diametrically disposed speakers connected; and finally 400 revolutions per minute with only one speaker connected. It will be understood of course, that the phase relationship of energization of the speakers 1, 2, 3, 4, 5, and 6 is all the same, and as more fully explained in my prior Patent No. 3,100,024.

In order appropriately to connect the speakers 1 to 6, a centrifugal switching device 151, carried by the drum 150 is provided. The device 151 cooperates with only four external leads, 152, 153, 154, and 155 illustrated in FIGS. 9 and 10. These external leads connect to the centrifugal switch 151 through two slip ring assemblies 156 (FIG. 9) and 157 (FIG. The leads 152 and 153 conduct to the slip ring assembly 156, power for operating logic elements to be hereinafter described. The leads 154 and 155 conduct the electrical output of the organ to the slip ring assembly 157. and 159 connect to the external leads through the assembly 157. Across the internal leads, the speaker 1 is permanently connected. The other speakers 2, 3, 4, 5, and 6 are controlled by a logic network carried by the rotor. This network incorporates logic elements in the form of three relays A, B, and C. These relays have coils 160, 161, and 162 that may be energized by power supplied by leads 152 and 153.

The relay coils 160, 161, and 162 are operated in accordance with the position of the centrifugal switch arm 163. The arm 163 connects through the slip ring assembly 156 to one of the power leads 152. A common side of the relays 160, 161, and 162 all connect through the slip ring assembly 156 to the other of the-power leads 153. The switch arm 163 sweeps past a series of contact segments connected to the coils. The arm 163 has four defined positions in accordance with the speed of operation of the rotor, and is indicated by the legends. In the first position, corresponding to 66 r.p.m., the arm 163 engages no segments. In the next position, corresponding substantially to 133 r.p.m., the arm 163 engages a segment 164 to energize coil 162 of relay C. At the next position, corresponding substantially to 200 r.p.m., segments 165 and 166 are engaged thus to energize coils 161 and 162 of relays C and B. At the final position of the contacting arm 163, corresponding substantially to 400 r.p.m., segments 167, 168, and 169 are all engaged resulting in energization of the coils of all relays C, B and A.

When the arm 166 is at the 66 r.p.m. position circuits Internal leads 158' are effected for all speakers. Thus speakers 2 and 6 have a circuit that includes the normally closed contacts 170 of the relay C. Speakers 3 and 5 have a circuit including a normally closed contacts 171 of the relay B. Speaker 4 has -a circuit including normally closed contacts 172 of the relay A. Thus all speakers are operative.

When the arm 163 arrives at the 133 r.p.m. position, relay contacts 170 open, thus disconnecting speakers 2 and 6 from the leads. Normally open shunt contacts 175 of relay C close to short-circuit both speakers 2 and 6. Speakers 3 and 5 remain in circuit due to the fact that relay B is yet de-energized. But speaker 4 is disconnected by virtue of the opening of contacts 172. At the same time a short-circuit path is effected by the aid of normally opened contacts 176 of relay C and normally closed contacts 177 of relay B that together shunt speaker 4. Accordingly equiangularly spaced speakers 1, 3, and 5 operate and thus produce the characteristic recurrence rate of the sound radiation pattern.

When the arm 163 moves to the 200 r.p.m. position, relays B and C both operate. Speakers 2 and 6 are disconnected as before. Speakers 3 and 5 are now also disconnected by virtue of the opening of contacts 171. Shortcircuiting cont-act 179 operated by relay B isolate speakers 3 and 5. Speaker 4, however is reconnected through an alternate path that includes normally open relay contacts 181 of relay B and normally closed relay contacts 182 of relay A. At the same time, the short-circuit path previously provided by the relay contacts 176 is operated by operation of the normally closed relay contacts 177. Accordingly diametrically opposite speakers 1 and 4 operate, and the characteristic recurrence rate for the sound radiation pattern is again produced.

At the third position of the arm 163 all relays operate. Speakers 2, 3, 5, and 6 are disconnected as previously described. Speaker 4 is likewise disconnected by opening of the relay contacts 182. At the same time a shortcircuit path is provided by normally open relay contacts 183 operated by relay A.

The segments engaged by the arm 163 have a suitable angular extent to insure operation despite a slight change or deviation in the speed of operation of the drum. It will be understood of course that coupled to the drum 150 are suitable motive means fior achieving rotation at the selective rates.

The inventor claims:

1. In apparatus for producing acoustic pulsato: a support mounted for rotation about an axis; means forming a plurality of angularly spaced sound channels on the support, said sound channels having sound emitting openings spaced from the axis of said support; means imparting rotation to the support at selected rates for determining the intensity of pulsato produced by the sound emitting openings of said channels; and switching means changing the operative number of sound channels in accordance with the rate of rotation of said support in order to maintain substantially constant, the rate of recurrence of the sound radiation pattern produced by said sound channels whereby the characteristic pulsato rate is maintained despite changes inthe rate of rotation of said support.

2. The combination as set forth in claim 1 in which said switching means comprises a closure for at least one of said sound channels, and centripetal-centritugal actuator means carried by said support and coupled to said closure to open the same below a selected speed and to close the same above a selected speed.

3. The combination as set forth in claim 1 in which there are four equiangularly spaced sound channels, said switching means comprising a closure for three of said channels; first centripetal-centrifugal actuator means for closing the closures of those two of the sound channels that are diametrically opposite each other, and only when said support reaches a speed of at least about 200 revolutions per minute; and second centripetal-centrifugal actuator means for closing the closure of the remaining sound channel, and only when said support reaches a speed of at least about 400 revolutions per minute.

4. 'T he combination as set forth in claim 1 in which a plurality of speakers are mounted'on said support and register with said sound channels respectively; and a switch for determining the rate of rotation of said support; and a common actuatorfor said switch and said switching means.

5. The combination as set forth in claim 1 in which a plurality of speakers are mounted on said support and register with said sound channels respectively and a centripetal-centrifugal actuator mounted on the support for operating said switching means in accordance with the rate of rotation of said support. I

6. The combination as set forth in claim 1 in which a pair of speakers are mounted on said support and register with a pair of sound channels located diametrically on said support; slip ring means carries by the support and cooperable with external leads connected to the organ output said switching means including a centripetal-centrifugal switch having one position below a speed of about 400 revolutions per minute, and a second position at a speed of about 400 revolutions per minute; circuit means connecting one of said speakers to said slip ring means and dependent upon said switch being in its said one position; circuit means short-circuiting said one of said speakers and dependent upon said switch being in its said second position; and circuit means connecting the other of said speakers to said slip ring means independently of said switch.

7 The combination as set forth in claim 1 in which a plurality of speakers are mounted on said support and register with said sound channels respectively; said switching means changing the number or" speakers connected to the signal source; and means for short-circuiting those speakers disconnected from the signal source for damping sympathetic vibrations thereof.

8. The combination as set forth in claim 1 in which six speakers are equiangularly mounted on said support and register with said sound channels respectively; circuit means cooperable with said switching means to connect all of said speakers to a signal source when said support is rotated at a rate of about 66 revolution per minute, to connect alternate speakers to said signal source when said support is rotated at a rate of about 133 revolutions per minute, to connect diametrically disposed speakers to said signal source when said support is rotated at a rate of about 200 revolutions per minute, and to connect only one of said speakers to said signal source when said support is rotated at a rate of about 400 revolutions per minute.

9. The combination as set forth in claim 8 together with a logic circuit carried by said support and a speed respon sive element for operating said circuit means.

References Cited by the Examiner UNITED STATES PATENTS I 2,114,680 4/1938 Goldsmith 179 -1 3,084,585 4/1963 Wayne s4. 1,24 3,100,024 8/1963 Leslie 181-27 LOUIS J. CAPOZI, Primary Examiner.

Claims (1)

1. IN APPARATUS FOR PRODUCING ACOUSTIC PULSATO; A SUPPORT MOUNTED FOR ROTATION ABOUT AN AXIS; MEANS FORMING A PLURALITY OF ANGULARLY SPACED SOUND CHANNELS ON THE SUPPORT, SAID SOUND CHANNELS HAVING SOUND EMITTING OPENINGS SPACED FROM THE AXIS OF SAID SUPPORT; MEANS IMPARTING ROTATION TO THE SUPPORT AT SELECTED RATES FOR DETERMINING THE INTENSITY OF PULSATO PRODUCED BY THE SOUND EMITTING OPENINGS OF SAID CHANNELS; AND SWITCHING MEANS CHANGING THE OPERATIVE NUMBER OF SOUND CHANNELS IN ACCORDANCE WITH THE RATE OF ROTATION OF SAID SUPPORT IN ORDER TO MAINTAIN SUBSTANTIALLY CONSTANT, THE RATE OF RECURRENCE OF THE SOUND RADIATION PATTERN PRODUCED BY SAID SOUND CHANNELS WHEREBY THE CHARACTERISTIC PULSATO RATE IS MAINTAINED DESPITE CHANGES IN THE RATE OF ROTATION OF SAID SUPPORT.

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