US 3666273 A
To economically reproduce sound from a record, a fluidic sound reproduction and amplification system is provided. This system embraces a phonograph pickup, a fluidic amplifier and an output horn coupled together to provide low-cost audio amplification with virtually unlimited life.
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Description (OCR text may contain errors)
INVENTORS ROBERT A. KANTOLA.
United States Patent Kantola et a1.
[ 1 May 30, 1972 [541 FLUIDIC SOUND REPRODUCTION SYSTEM  inventors: Robert A. Kantola, Scotia, N.Y.; Norman 11. West, Decatur, 111.
 Assignee: General Electric Company  Filed: Jan. 13, 1970 ] App]. No.: 2,473
 U.S. Cl ..274/6,137/8l.5
51 Int. Cl. ..Gllb 9/00  Field of Search ..137 s1.s; 274/6, 27, 29
 References Cited UNITED STATES PATENTS La Rue ...274/6 Robbins ..274/6 Horton ..137/8l.5
Primary ExaminerHarry N. Haroian Attorney-Thomas A. Briody, W. Joseph Shanley, Frank L. Neuhauser, Oscar B. Waddell, Joseph B. Forman, Stanley C. Corwin and W. J. Shanley, Jr.
 ABSTRACT To economically reproduce sound from a record, a fluidic sound reproduction and amplification system is provided. This system embraces a phonograph pickup, a fluidic amplifier and an output horn coupled together to provide low-cost audio amplification with virtually unlimited life.
7 Claims, 3 Drawing Figures FLUIDIC SOUND REPRODUCTION SYSTEM BACKGROUND OF THE INVENTION This invention relates to sound reproduction systems, and more particularly to an inexpensive fluidic sound reproduction system which incorporates a fluidic audio amplifier.
A review of the history of phonographs reveals that prior to the advent of electric sound reproducing systems, acoustical systems were capable of achieving excellent sound quality. However, due to their lack of an amplifier, these systems lacked the desired sound power. Accordingly, an important object of the present invention is the provision of a fluidic sound reproduction system which is constructed and adapted to provide improved sound power amplification.
Another object of the present invention is to provide an improved fluidic sound reproduction system incorporating a minimum number of parts.
Still another object of this invention is to provide an improved phonograph which is extremely simplified in construction and economical in cost.
A further object of this invention is to provide an improved sound reproduction system which comprises a phonograph pickup, a fluidic audio amplifier, and one or more output horns.
SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided a fluidic sound reproduction system that includes a motor driven turntable. A stylus is disposed for mechanical cooperation with a grooved record placed upon the turntable. A diaphragm is connected to the stylus for conversion of motion of the stylus into pressure signals. With such an arrangement, a fluidic proportional device is provided. This device has its input connected to the diaphragm by a tube, for transmitting pressure signals from the diaphragm to the device. The output of the fluidic proportional device is connected to at least one pressure responsive device such as a diaphragm, which in turn drives an output horn. Such an arrangement eliminates the necessity of using relatively fragile electronic components, and achieves a very low cost sound reproducing device, the amplifier of which has an inherently unlimited life.
Further aspects of our invention will become apparent hereinafter, and the specification concludes with claims that particularly point out and distinctly claim the subject matter which is regarded as the present invention. The invention, however, as to organization and method of operation, together with further objectives and advantages thereof, may best be understood by reference to the following description when taken in conjunction with the accompanying drawing in which:
FIG. 1 is a schematic representation of a fluidic sound reproduction system embodying one form of the present invention,
FIG. 2 is an illustration of a stereo phonograph embodying the invention, and
FIG. 3 is a typical configuration of a beam deflector amplifier.
DESCRIPTION OF PREFERRED EMBODIMENTS Referring now first to FIG. 1, wherein there is shown a schematic illustration of the present invention, there is a motordriven turntable which is rotatable in direction D and has a central spindle 12.
For mechanical cooperation with the grooves of a record R placed upon the turntable 10, there is provided a stylus 14 supported by a tone arm (not shown) for movement about its pivot 16. The stylus 14 is mechanically connected to a diaphragm 18, which also may be part of the tone arm structure. The diaphragm 18 may be of any conventional type, such as aluminum, and has its output connected via a tube 20 to the control input 24C of the first stage 24 of a four-stage fluidic proportional device 26. The fluidic proportional device 26 is of the multi-stage type, being characterized by a high input impedance and a low output impedance, and it includes four beam-deflector amplifier stages 24, 28, 32, and 36, the composite of which has its input and output of a single-sided nature.
The concept and potential usefulness of beam-deflector amplifiers was advanced by B. M. Horton, for example by his article entitled Amplification by Stream Interaction, in Northeast Electronics Research & Engineering Meeting, IRE, Boston, Nov. 1960. With beam-deflector amplifiers, the input signal is the difference in flows or pressures present at the two control ports, and the output signal is the difference in flows or pressures at the receiver (i.e. output) ports. For example, a typical configuration of a beam-deflector amplifier is shown in FIG. 3. It includes a power supply inlet, P, a pair of control ports Cl and C2 and a pair of receiver (output) ports 01 and 02. It will be noted that there is a generally heart shaped area H between the control ports C1, C2 and the receiver ports 01, 02. This area H is provided to help preclude any undesirable attachment or interaction of the jet with the walls of the amplifier.
The geometrical configuration of beam deflector amplifiers may be considered similar to the fluid flip-flop type amplifier, except for the fact that in beam-deflector amplifiers the sidewalls in the unbounded jet region (between the control ports and receiver ports) are removed considerably from the jet in area H to prevent its attachment or interaction with the amplifier walls.
With air entering power supply inlet P at a pressure of l p.s.i.g. above normal atmospheric pressure, the jet J in the beam deflection amplifier configuration of FIG. 3 is deflected by the difi'erence in flow between the control ports Cl and C2. This deflection of the jet J provides a difference in flow to the receivers which is achieved by the momentum and pressure of the control flow (AC Cl C2). The output signal A0 is equal to the difference in flow or pressure from the receiver ports 01 and O2 (i.e. A 0=0l 02).
Turning now to a further description of the fluidic proportional device 26, it will be noted that the first amplifier stage 24 includes only one control port 24C and two receiver ports 2401 and 2402. The receiver ports 2401 and 2402 are fluidically coupled, respectively, to the control ports 28C] and 28C2 of the second amplifier stage 28. The receiver ports 2801 and 2802 are fluidically coupled, respectively, to the control ports 32C1 and 32C2 of the third amplifier stage 32, which in turn has its receiver ports 3201 and 3202 fluidically coupled to the control ports 36Cl and 36C2 of a fourth amplifier stage 36. The fourth and last amplifier stage 36 of device 26, has a single receiver port 360 which is fluidically coupled to a diaphragm 40 which drives horn 44. Together, the diaphragm 40 and horn 44 serve as a single audio output device 46 for reproducing sound from the grooves of record R. Diaphragm 40, like diaphragm 18, may be of any conventional type, such as aluminum.
It is important to note that the embodiment of the invention illustrated in FIG. 1 also includes an inductive shunt 48 which is located between the diaphragm l8 and the control port or inlet 24C of first amplifier stage 24. The shunt 48 is provided to help remove any steady-state bias and also to help tailor the low end of the frequency response. In addition, the inventive embodiment also includes an inductive shunt 50 which is located between the single receiver port 360 (of the fourth amplifier stage 36) and diaphragm 40. This shunt 50 serves the same purposes as the aforementioned shunt 48.
Turning now to a detailed explanation of the manner of operation of the fluidic sound reproduction system shown schematically in FIG. 1, it will be noted that upon rotation of the turntable l0, record R placed thereupon moves with an angular rotation in the direction D. Stylus 14 mechanically cooperates with grooves of the record R and pivots about its support 16 to actuate the diaphragm 18. Since the diaphragm 18 is connected via tube 20 to the control inlet 24C of stage 24 of the four stage fluidic proportional device 26, the pressure signals emanating from the diaphragm 18 via tube 20 are thereupon amplified in the four stage fluidic proportional device 26 so that when they reach the inlet of diaphragm 40, they readily actuate the diaphragm to provide a significant audio response at horn 44.
In a working system actually constructed in accordance with the schematic representation of FIG. 1, we have achieved a pressure gain of more than 50 to l, with signal inputs of 0.00l p.s.i. The parameters which we used for this system were as follows:
pp y Amp. Amp. Nozzle Size Number of Pressure Stage Width x Depth Parallel Paths (p.s.i.g.)
It is important to note that the phonograph pickup and output horn of the invention embodied in FIG. 1 may be of any number of possible configurations. In addition, the pickup stylus assembly may be of any material or construction that allows economical conversion of mechanical motion to pressure signals. The output means of the device may also be of any material or construction which allows effective transfer of the signal from the output of the amplifier to the surrounding medium.
It will be further understood that in accordance with the present invention a second amplifier and horn may be utilized together with a two axis pivotal arrangement on the pickup, to achieve stereo reproduction.
One example of a stereophonic sound reproduction system embodying the invention is shown in FIG. 2. As shown therein, the record changer 100 includes a turntable 110 supported on a deck 111. The turntable 110 has a stereo record SR located on its spindle 1 l2, and a tone arm 113 pivotally supported on the deck 1 1 1. Tone arm 113 is specially constructed so that its pickup 117 has a pivotally supported stylus (not shown) which picks up both the left and right signals from the grooves of a record. Each of these L and R signals is fed to a separate diaphragm (not shown) located in the pickup 117. The diaphragms are fluidically coupled respectively to tubes 120L and 120R of the tone arm 113. Tube 1201. is fluidically connected to a four stage fluidic proportional device 1261., which is in turn coupled to the audio output device 146L. Tube 120R is fiuidically coupled to a four stage fluidic proportional device 126R, which is coupled to the audio output device 146R. Both of the audio output devices 146L and 146R are shown as loudspeakers. With such an arrangment as that shown in FIG. 2, it will be apparent to those skilled in the art that the system propounded by the present invention may be effectively used to achieve efiicient multi-channel sound reproduction, such as stereophonic reproduction of sound from pre-recorded stereophonic records.
It will now, therefore, be seen that the fluidic sound reproduction system of the present invention achieves sound reproduction from records without requiring any electronic components. Such an approach involves a very simplified construction at a most economical cost.
Although the invention has been described with respect to certain specific embodiments, it will be appreciated that various modifications may be made by those skilled in the art without departing from the spirit and scope of the invention.
What is claimed as new and desired to be secured by Letters Patent in the United States is:
l. A fluidic sound reproduction system comprising:
a motor-driven turntable;
a stylus disposed for mechanical cooperation with a grooved record placed upon said turntable; a diaphragm coupled to said stylus for converting motion of said stylus into fluidic pressure signals; at least one audio output device for producing sound in response to fluidic pressure signals furnished thereto; and
fluidic circuit means coupling said diaphragm to said audio output device, said fluidic circuit means including a fluidic proportional device for amplifying fluidic pressure signals, first fluidic coupling means coupling said diaphragm to the input of said fluidic proportional device so as to convey fluidic pressure signals from said diaphragm to said fluidic proportional device, second fluidic coupling means coupling the output of said fluidic proportional device to said audio output device for enabling said audio output device to reproduce sound recorded on the record rotated by said turntable and contacted by said stylus, and an inductive shunt connected to said first fluidic coupling means for preventing existence of steady-state bias at the input of said fluidic proportional device.
2. The fluidic sound reproduction system of claim 1 wherein the fluidic proportional device comprises a beam deflector type of fluidic amplifier.
3. The fluidic sound reproduction system of claim 1 wherein the fluidic proportional device includes multiple stages.
4. The fluidic sound reproduction system of claim 1 wherein the audio output device comprises a horn.
5. The fluidic sound reproduction system of claim 1 wherein the fluidic proportional device includes multiple stages of the beam deflector amplifier type, the first of said stages having a single control port, and second, third and fourth stages each having two oppositely disposed control ports.
6. The fluidic sound reproduction system of claim 5 wherein the first amplifier stage has two receiver ports each of which is fluidically coupled to an associated one of the control ports of the second amplifier stage, respectively, said second amplifier stage having two receiver ports each of which is fluidically coupled to an associated one of the control ports of the third amplifier stage, respectively, said third amplifier stage having two receiver ports each of which is fluidically coupled to an associated one of the control ports of the fourth amplifier stage, respectively, said fourth amplifier stage having a single receiver output port connected to the audio output device.
7. The fluidic sound reproduction system of claim 1 wherein the stylus is adapted to pick up both left and right recorded signals from the grooves of a stereophonic record, said audio output device reproducing one of said recorded signals; said system further including an additional diaphragm, an additional audio output device and an additional fluidic circuit means coupling said additional diaphragm to said additional audio output device to enable said additional audio output device to reproduce sound corresponding to said right signal, thereby to achieve stereophonic sound reproduction from said record.