Патент USA US2403696код для вставки
July 9, 1946. >H_ c, WARNER 2,403,696 ELECTRICAL SOUND REPRODUCING APPARATUS Filed Aug. 14, 1944 )////////////////////////W/////)'//// - IN VEN TOR. HARRY C. WARNER. BY . aI (/‘ ‘f ATTORNEY. 2,403,696 Patented July 9, 1946 r UNITED STATES PATENT. OFFICE 2.403.896 - ELECTRICAL SOUND REPRODUCING APPARATUS Harry C. Warner, San Francisco, Calif. ‘Application August 14, 1944, Serial No. 549,379 ' 8 Claims. (Cl. 179-10041) 2 1 parts between, which terminals H and I2 extend My present invention relates to electrical sound reproducing apparatus, and more particularly to from one end for connection with a vacuum tube ampli?er circuit. At their other end the halves of the housing H) are provided with diagonally disposed and registering half-round grooves l3 that will provide a cylindrical seat for two rela tively soft rubber collars l4 and i5 within which a record needle supporting member I6 is pivot ally mounted. Carried by the member ii there a device for providing a modulated input signal current for a vacuum tube amplifying system. An object of the invention is to provide anew and novel form of current modulating device which is particularly adapted to operate in con junction with a sound responsive device, such as a phonograph pick-up or microphone, to provide an input signal current for a vacuum tube am pli?er circuit. ' 10 is a suitable thumbscrew I‘! by means of which a needle [8 may be secured within the support It. Extending inwardly, and also carried by the sup port It, there is an operating arm l9 that is adapted to control a variable'resistance device medium may be varied in a new and novel manner 15 20 which embodies what are now considered to be the novel aspects of my present invention. As to provide a signal current for the input of a vac here shown, the variable resistance device 20 is uum tube amplifying system. in the form of a small capsule which is positioned A further object of the invention is to provide within a recess 2| formed in one side of the hous a phonograph pick-up device of novel construc tion for use with a vacuum tube amplifying sys 20 ing l0 so that its axis will be approximately in line with a projection of the axis of the record engag tem of the type employed to reproduce the re ing needle I 8. As will hereinafter appear, the de cording upon a sound record. ' vice 20 is believed to operate on the principle of a Other objects and advantages of the invention variable resistance and it is here shown as being will be in part evident to those skilled in the art, and in part pointed out hereinafter in the fol 25 connected at its ends through conductors 22 and 23 to the terminals II and I2 which in turn are lowing description taken in connection with the adapted to connect with the input terminals of a accompanying drawing, wherein there is shown vacuum tube ampli?er circuit. by way of illustration and not of limitation, pre Reference is now made to Figures 2 and 3 of ferred embodiments of the invention. In the drawing; . 30 the drawing for a more detailed description‘ of the invention as embodied‘ in a device suitable for Figure 1 is a. substantially normal-size view of use as above indicated. In these ?gures the device the invention as embodied in a pick-up for the 20 illustrated in Figure 1 is shown on a greatly tone arm of a phonograph, enlarged scale. As at present constructed, the Figure 2 is an enlarged sectional view with unit or capsule has a diameter of approximately parts broken away and showing details of con Another object of the invention is to provide a current modulating device of the resistance type in which the resistance of a liquid conducting struction of a preferred embodiment of a feature seven thirty-seconds of an inch and an overall of the invention, length of one-half inch, and the amount of liq - Figure 3 is a transverse sectional view taken uid required as a variable resistance medium, as will hereinafter appear, amounts to approximately along line III—III of Figure 2, Figure 4 is a diagrammatic wiring diagram 40 two full drops. In its preferred form the device showing a system of connections by which my device may be associated with the input of a vacuum tube amplifying circuit, and Figures 5 and 6 are diagrammatic views show ing other adaptations of the invention. In Figure 1 of the drawing, for the purpose of illustration, I have shown my invention as em bodied in a pick-up device, such as may be used 20 comprises a length of relatively soft rubber tubing 24 that is adapted to-be closed at its ends by means of electrodes 25 and 26 that project into the ends thereof so as to form an air-tight liquid 45 containing chamber 21 therebetwcen which is adapted to be ?lled with a liquid resistance me dium. As here shown, the electrodes 25 and 26 are each provided with an annular recess 28 into which the ends of the tubing 24 are clamped by upon a sound record. In this showing the nu 50 means of suitable binding rings 29. Extending between the electrodes 25 and 26 there is a spac meral I0 designates a supporting housing of in ing member 30 of insulating material which is sulating material, such as is now generally used seated at its ends within the electrodes 25 and as a mounting for a piezo-electric crystal of a to electrically reproduce the recorded program phonograph pick-up device. ri'his housing 10 26 in such a manner that they will be held in is constructed in two substantially symmetrical 65 properly spaced relation with respect to each 2,403,696 other. This spacing member 30 has an annular collar or enlargement ll intermediate its ends which is chamiered so as to provide for a sub 39. This electrode 2,5 is also shown as connected through a capacitance 40 to the grid 3'! of the stantially knife edge engagement thereof with the inside wall of the tubing 24, and at one point vacuum tube 38. At the other side of the device 20 the electrode 28 is connected through a con around its circumference, as is more clearly shown in Figure 3 0f the drawing, this annular collar and through a grid leak resistance 42 to the grid 31 of the vacuum tube 36. A plate coupling-rm or enlargement 3| is provided with a notch or cut ductor 4| to the grounded side of the filament 3| sistance 43 is also here shown as connected across away portion 32 that serves to provide a con the plate or output circuit of the vacuum tube 36. stricted conductance path in the liquid resist~ 10 This output circuit also has‘a blocking capaci ance medium contained within the chamber 21. tance 44 in one side thereof. When the device 20 As is more clearly shown in this latter figure of is connected in this manner, it is believed that a the drawing, the rubber tubing 24 is adapted to current flow will be established through the con be engaged on its outer surface, at a point im mediately adjacent the notch or cut~away por 15 ductor 35, the coupling resistance 34 and the con ductor 33 to the electrode 25, and from there tion 32, by the operating member I9 previously referred to as actuated in accordance with the movements of the record engaging needle l8 when the latter is operating upon a sound recording. In Figure 4 of the drawing I have shown a dia~ grammatic circuit by means of which my inven tion may be associated with a vacuum tube ampli fier circuit. At this point it should .be stated that while it is believed that the operation of my im~ proved device is based upon the principle of a variable resistance as a modulating means, it is to be understood that this action may be ac counted for by some other theory. The nature of the liquid resistance medium does not appear to be of major importance, but it has been found that grain alcohol or, in fact, ordinary whiskey, may be used as a resistance medium between the electrodes 25 and 28. The fact that an alcohol, as distinguished from an acid electrolyte, has been through the variable resistance medium to thc electrode 25 and via the conductor H to ground at the point of connection with the filament ll of the vacuum tube 36. Now, with this current flowing through the variable resistance medium of the device 20, it will be seen that when the recording needle I! is stationary, no change will occur in the nature of the conductance path be’ tween the electrodes 25 and 26 and, therefore, a. substantially uniform ?ow of current will prevail. However, when the nature of the conductance path formed by the resistance liquid medium in the constricted zone of the chamber 21 is varied, as by movements of the record engaging needle I8, it is believed that these changes will produce a modulation of this current which will then be transmitted through the condenser 40 and the grid leak resistance 42 to the grid 31 of the vacuum tube 36, and in this way the vacuum tube 36 will found to be particularly effective in this instance, 35 operate to produce an ampli?ed signal current may be due to its inactivity with respect to the that may be used to operate a loud speaker or rubber tubing. There is also the known fact other similar device. It is also conceivable that that the alcohols have a high inductive capaci the circuit through the variable resistance liquid tance value and it is, therefore, possible that the medium of the device 20 may also be subjected use of such a liquid resistance medium may in 40 to a high frequency carrier current originating in some way involve a capacitive change in the cir the plate circuit of the vacuum tube 35 upon cuit between the electrodes 25 and 26. In any which the modulated signal current may be. event, it has been demonstrated by actual use superimposed. that a device constructed as above described is While I have illustrated and described my in capable of providing for the reproduction of re 45 vention as embodied in a device for use in con corded music in a much smoother and more satis nection with the reproduction of phonograph re factory manner than is possible with the best cordings, it will be readily understood that the piezo-electric crystals now on the market for this device 20 may be found useful in other ?elds. purpose. Among other advantages, it has been found possible, by changing the resilience or 50 For example, as shown in Figure 5 of the draw ing, it may be used in connection with a sound thickness of the tubing 24, to provide for almost wave responsive microphone by operating the any desired frequency response. For example, a device 20 in association with a sound wave inter thin walled tubing has been found to be very cepting diaparagm 45 or, as shown in Figure 6 responsive in the higher frequency range, while in the lower frequency range the response is more 55 of the drawing, wherein the device is illustrated as associated with a mechanically operated de pronounced as the thickness of the tubing 24 is tector device 46 that may be placed against any increased. Another point is that by changing the nature of the liquid and/or the length of the current path therethrough, it will be possible to match the input impedance of any ampli?er cir cuit with which the device may be used. And ?nally, it has also been discovered that the oper ation of the device is not affected by changes in temperature or humidity, which is a character istic not possessed by the so-called piezo-electric crystal microphone and pick-up devices. In operation, when the device 20 is associated with a vacuum tube ampli?er circuit, as‘ dia grammatically shown in Figure 4 of the drawing, vibrating surface for the purpose of reproducing electrical impulses corresponding to the move ments of a vibrating member. While I have, for the sake of clearness and in order to disclose the invention so that the same can be readily understood, described and illus trated speci?c devices and arrangements, I desire to have it understood that the invention is not limited to the specific means disclosed, but may be embodied in other ways that will suggest them selves to persons skilled in the art. It is believed that this invention is new and it is desired to claim it so that all such changes as come within one of its electrodes, as for example, the electrode 70 the scope of the appended claims are to be con 25, will be connected through a conductor 33, sidered as part of this invention. a coupling resistor 34 and a conductor 35 to the Having thus described my invention, what I positive side of the output or plate circuit of a claim and desire to secure by Letters Patent is: vacuum tube 38, which tube is here shown as 1. In a phonograph pick-up of the character having a control grid 31, a ?lament 38 and a plate 75 described, the combination of a supporting hous aeoacoc ing adapted to be carried by the tone arm of a phonograph, a stylus pivotally mounted'upon and extending from ‘said housing adapted to en the combination of an input tube having ?la ment, grid and plate connections, a variable re sistance medium comprising spaced electrodes with a column of conducting liquid therebetween, gage a sound record, a deformable liquid con circuit connections between one of said electrodes and the plate and through a capacitance to the grid of said vacuum tube, 'a circuit connection taining receptacle having spaced electrodes mounted therein and adapted 'to be connected in the grid circuit of a vacuum tube with the plate to ground potential of said vacuum tube im between the other of said electrodesand the fila ment grounding circuit of said tube, whereby the uid within said receptacle forming a variable 10 plate potential of said tube will be impressed up on said liquid through said electrodes, and me conductance path between said electrodes, and‘ chanical means responsive to sound wave im means operated by movements of said stylus pulses adapted to ‘vary the cross-section of said adapted to deform said receptacle and'thereby column of conducting liquid between said elec change the conductance of said liquid in accord pressed therebetweenya current conducting liq 15 trodes, whereby .a modulated current correspond ance with the recording upon a sound record. ing to the response of said sound wave responsive . 2. In a phonograph pick-up of the character means will be impressed upon the grid of said in described, the combination of an insulated sup porting housing adapted to be carried by the tone ' put tube. 6.‘ In a variable resistance unit for a current arm of a phonograph, a stylus pivotally mounted upon and extending from said housing adapted 20 modulating device, the combination of a pair of spaced electrodes, a tubular rubber sleeve secured to engage a sound record, a tubular rubber re at its ends around each of said electrodes and ceptacle having spaced electrodes closing the forming a liquid containing chamber therebe ends thereof and adapted to be connected in the tween, means between said electrodes operating input circuit of a vacuum tube with the plate to ground potential of said vacuum tube impressed 25 to divide said chamber into two parts with a re stricted communicating passageway therebe therebetween, 'a liquid medium within said recep tween, a current conducting liquid disposed with tacle forming a variable conductance path be in said chamber forming a variable resistance tween said electrodes, and means operated by between said electrodes, and means including a movements of said stylus adapted to deform said tubular receptacle between said electrodes to 80 sound wave responsive device adapted to distort the wall of said tubular sleeve adjacent said re— thereby vary the cross-section and conductance - stricted passageway, whereby the overall resist of said liquid between said electrodes in accord ance of said liquid conducting \rnedium will be ance with the recording upon a sound record. changed in accordance with the operation oi’ 3. In a control device for vacuum tube circuits, the combination of a tubular non-metallic mem ber having current conducting electrodes form ing closures at the ends thereof, a current con ducting liquid forming a conductance path with in said tubular ‘member between said electrodes, 35 said means. " I 7. In a control device for vacuum tube circuits, the combination of a capsule-like unit compris ing an elongated yielding body portion of insu lating material having current conducting elec means forming a constricted cross-section of said 46 trodes sealed in and closing the ends thereof to provide a ?uid containing cavity, a ?uid medium liquid. at a point between said electrodes, and a disposed within said capsule and forming a cur sound wave responsive means adapted to deform said tubular non-metallic member at the point . rent conducting path between said electrodes, of said constriction to thereby change the over 45 and means associated with the yielding body por tion of said capsule adapted to exert a deform ' all conductance of said liquid between said elec ing pressure thereupon, whereby the conductance trodes in accordance with sound wave impulses to . of the current path through said ?uid medium between the electrodes at the ends of said cap 4. In a sound wave control device for vacuum 50 sule will be varied in accordance with the oper which said sound wave responsive means may be exposed. ations of said means. _ tube circuits, the combination of a grid con 8. In a control device for vacuum tube cir trolled vacuum tube, a receptacle having opposed cuits, the combination of a capsule-like unit hav and insulated electrodes mounted therein and ing a yielding body portion of insulating mate adapted to be connected through a capacitance in the grid circuit of said vacuum tube, connec-‘ 55 rial, current conducting electrodes sealed in the wall of said capsule and forming therewith a tions whereby the plate'potential of said vacuum closed ?uid containing cavity, a ?uid medium tube is impressed across the space between said disposed within said capsule between said elec electrodes, a liquid current conducting medium trodes and forming a current conducting path disposed between‘ said electrodes, means located between said electrodes forming a restricted cur 60 therebetween, and means associated with the yielding body portion of said capsule adapted to rent path in said liquid, and mechanical means exert a deforming pressure thereupon, whereby responsive to sound wave impulses adapted to the conductance of the current path through vary the cross-section of the restricted current said ?uid between said electrodes will be varied path in said liquid in accordance with the nature or sound wave impulses to which said mechani 65 in accordance with the operations of said means. cal means is exposed. HARRY C. WARNER. 5. In a sound reproducing vacuum tube circuit.