Патент USA US2104170код для вставки
Jan. 4,' 1938. K. SCHWARZ ‘ ‘ SOUND RECORDING DEVICE 2,104,170 ' Filed ‘Nov. 13, 1955 £119.11 25 4\ [.2 _ g1 Z7 5 3 ‘ 23 a 20 1e 7/1/7/4 INYVENTQR A KARL SCH/V432 I #éim" . ATTORNEY 2,104,170 Patented Jan. 4, 1938 UNITED STATES ‘PATENT OFFICE 2,104,17 0 SOUND RECORDING DEVICE Karl Schwarz, Berlin, Germany, assignor‘ to Klang?lm G. m. b. H., Berlin, Germany, a - corporation of Germany Application November 13, 1935, Serial No. 49,465 . In Germany April 15, 1935 . (Cl. 179-1003) her which admits of rotational movements of the This invention relates to signal recording de 5 Claims. mirror about the longitudinal axis of the string application Serial No. ‘28,418, ?led June 26, 1935 , support and in that the mounting and adjusting (D—10,191), and has for its principal object, the means for the string support and the mirror are rotatable about an axis which forms with the 5 .provision of an improved signal recording mech string support an angle that corresponds to the anism and method of operation whereby a re vices such as that disclosed in my copending cording element, such as a galvanometer mirror or the like, is vibrated about one axis in accord ance with the signal to be recorded and is ro wrtated about another axis in accordance with the signal volume. The present invention involves features similar in some respects to those dis closed by a copending application of EdwardW. Kellogg, Serial No. 531, filed Jan. 5, 1935 and 15 assigned to Radio Corporation of America but differs therefrom in the constructional details and operating principle of recording mechanism. The object of the copending application (Se rial No. 28,418) is the provision of a method and‘ 20 means adapted to produce variable area type records that are free from background noises. To this end a stationary serrated diaphragm or light-stop serves to contour and bound a light pencil or beam, which is caused to impinge upon 25 a mirror oscillated about an axis or pivot at the frequency of the signal, the said pivot being posi tioned perpendicularly at right angles to one of the edges of the stop. This mirror is also moved in response to the signal volume current about diaphragm angle. This new arrangement makes it possible to effect adjustment of the mirror in the sense of the di?erent coordinates essentially independently of one another. Inasmuch as the 10 mirror involves very little inertia, it is preferable that the mirror should be excited about the string sup-port in accordancewith the signal vi brations. The supporting and ‘adjusting system involves far more inertia and is less suited and 15' able to follow the tonalposcillations. In fact, this system is called upon to experience comparatively slow vibrations, say, up to around 20 cycles per second. These oscillations are due to fluctuations of the direct current generated by recti?cation N 0of the signal currents, the intensity of which cor responds to the volume of the sound or signal to be recorded and is subject to but slight alterations in comparison with the tonal vibrations. Inasmuch as it is necessary to provide a mag net in whose ?eld the mirror excited at tonal fre quency is capable of oscillating, and since this 25 magnet would greatly increase the weight of the system which is to vibrate in unison with the sig another pivot positioned at right angles to the nal volume current, means are provided which 30' other edge of the stop. The two axes about which make it unnecessary for the magnet to partake the mirror must be caused to oscillate according of the oscillations of the supporting system. This is made practicable in that the pole-shoes of the to the method disclosed in the aforesaid copend magnet are yieldingly' united therewith. In this ing patent application, thus form an angle rela 35 tive to each other which is equal to- the ‘angle case, the pole-shoes and more particularly the 03 vi. tips thereof which govern the intensityof the formed between two abutting edges of the multi tooth mask or light-stop. In the case where the magnetic ?eld within which the mirror is made edges of the multi-serrated light-stop are at right to oscillate, will be able to vibrate in accordance , angles to one another; the oscillating mirror, as 'with the signal amplitude or volume, whereas the 40 will thus be seen, must be pivotable about two magnet itself remains at rest. This yielding union 40 axes-being at right angles to each other. This between the pole-shoes and the magnet, however, must be chosen in such‘a way that the magnetic special requirement is somewhat vdimcult of ful ?ux in the pole-shoes will be large. It is there ?llment because the space available for the de vice is limited and replacement of the light valve fore suggested to choose a'high-permeability ma- , 45 in the sound recorder apparatus is likely to be terial throughout the pole-shoes, and to so taper 45 required. . ‘ _ ' 5 In addition to the di?iculties just ‘outlined, there are others which are due to the require ment that the center of the mirror should occupy 50 a de?nite position upon the optical axis, and that the mirror plane, in its zero position, should be in a de?nite position with'respect thereto. According vto the present invention, these di?i culties are obviated in that the mirror is sup “ ported ‘by a string, chord or other suitable mem the same at one place that the pole-shoes can, be readily bent in accordance with the oscilla tions of the supporting system. However, the same end is attainable in that the pole-shoes. terminate at their ends or tips in a plate or blade 50 of magnetic material, and that the latter is con-, nected with the magnet with the interposition of a tenuous layer of yielding or ?exible mate terial such as ‘rubber or the like. While this meansa small'gap between the pole-shoe and 551 2,104,170v the magnet ?lled with material of low permeabil ity, the magnetic ?ux in the pole-shoes will never theless be of the requisite intensity on the ground that the cross-sectional area at this place is con veniently large. The magnet, preferably a bar magnet, is dis posed below the supporting system, and the same has a central bore through which the driving sys tem of the noise control means may be shifted’ and made to engage. Screwed upon the ends of r' ‘ ‘ ‘ ing system in relation to the exciting means for the noise reduction currents effected in a way as stated, the device is inserted into the casing of the light valve so that it will thus be protected in a dust-proof and hermetical way. By the aid 5 of pressure (thrust) and tractile screws, the posi tion of the oscillation system in reference to the casing can be adjusted in any desired direction. The sequence in which the various adjustments ,must be accomplished, and more particularly in 10 ‘what Way the system oscillating at tone frequency must be constructed is described below in more detail by reference to the drawing illus rubber may be arranged. ' Owing to the fact that‘ trating one exempli?ed embodiment of the in the bar magnet are blocks or resting means in Which the ?exible pole-shoes may be fastened by clamping action or upon which the said layer of the said supporting blocks are screwed on, this ' vention. ' , , ' allows adjustment of the center of the mirror. In Referring to ' the drawing, fact, by shifting the same conditions can be made Fig. 1 shows asection laid through the light so that the center of the 'mirrorwill coincide with ' valve at right angles to the axis about which the the optical axis. - - I signal volume responsive oscillations take place, Fig. 2 shows a section at right angles to the 20 For driving and adjusting the supporting sysé ‘ tem there serves 'preferably'an electromagnetic other axis of rotation of the mirror about which the signal, responsive vibrations take place, the' system which is subject to a control action'pro casing having been omitted'in‘ this ?gure. , duced by a current which‘ is responsive to the sig Fig.‘ 3 is a View of the lightrvalve in the direc nal amplitude or volume. For this purpose there 25 is rigidly associated with the supporting system tion of the optical axis after removal, of casing, 25. a ferro-magnetic body which is hereinafter called and a tongue or reed whose free end is capable of ' Fig.’ 4 illustrates the mode of clamping the’ oscillating in front of the pole-shoes of a magnet." chord or string of theoscillating mirror. -The oscillating‘mirror I (Fig. '3) is supported This driving system is preferably designed so as to act as a so-called free oscillator. The exciting by a chord 2. In order "to facilitate and simplify coil embraces at one end the said tongue, while; the fastening of the mirror in reference to the at the other end it is seated in a ring magnet’ chordas well as'the clamping of the latter, 'a chord having rectangular cross-sectional'shape upon the ends of which pole-shoes are screwed fast, which bound an air-gap‘ in the middle of" as shown in Fig. 4 is used. The clamping and locking of the chord in the supp‘orting‘system 3 .may be effected in various ways. Thusat both The supporting vsystem could comprise either a' ends of the chord, bolts 4 provided with grips 5 knife edge system or a mechanical pivot 01'' else may be provided. These bolts’ may be sawed open be insured by supporting in more than one point, so that the chord may be inserted, and then the 40 provided that, upon eifecting a shift in these sup parts may be secured in reference to each other porting points, at least approximately rotation of by suitable clamp screws. By means of guide pins the supporting system about .the desired axis 28 which are seated in one-half'of the bolt and en gage in bores 29 of the other half of the bolt, passing through the mirror is insured. According to another aspect of this invention, relative slipping of the bolt members or halves 4.5 _ the supporting system bears upon leaf springs the is prevented; ‘By changing the relative distance of the bolts, the, free length of the chord is alter ends of which are capable of rotational move ments about their clamping or securing point. In 7 able and thus‘ also the natural period of the oscil~ latory system comprising the chord and the order to insure safe contact between the support > ing system and the said leaf springs also in case mirror. The'oscillatory system'j is subject to 'a driving . 50 of transportation, the supporting system is pro vided, say, with two bore holes through which two action set up by a ferro~magnetic plate on the strings engage. By tensioning these strings or oscillating mirror, and a magnetic ?eld set up chords, both the desired bearing pressure as well by ampli?ed microphone currents in the coils 1 as a convenient biasing tension in the leaf springs seated on the pole-shoes. The pole-shoes 6 are secured upon blocks or’ uprights 8 which are will be secured. , V ' The said leaf springs are clamped fast in a screwed upon ‘the bar magnet 9. Two types‘of the magnetic ring and in which, as stated, the said. tongue is capable of vibrating. body which, on the one hand,is rigidly united pole-shoe mounting according to this invention are illustrated inEig. 2. The left-‘hand pole-shoe with the ring magnets of the ground noise reduc - in Fig. 2 terminates in'a plateletvlll disposed’ on tion drive' system, while, on the other hand it 60 .serves' to adjust the entire vibrational system in the block 8 with interposition of>_a rubber disk or 60 reference to the casing of the light valve. The washer II. The right-hand pole-shoe‘ shows a_ V65 leaf spring. I2’which permits'thepole-shoe of;ex' securing of the leaf springs must be accom plished with a good deal of care in order that the periencing movements in reference to the block. rotational movements about the desired axis or .Also ‘at this place a rubber buffer is interposed pivot may result. The leaf springs are locked as indicated at H’. The‘ rubber. disk ll’ serves in position by screws which in case they have not to‘ dampen or deaden the vibrations of the leaf been completely tightened allow of a certain spring l2. Also thelayer of rubber on the left hand pole-shoe has this effect. .» amount of clearance or play between the springs Adjustment of theinatural period of oscillationI and the body. When adjusted,'these screws are of the mirror. is’ effected by adjusting the ‘free tightened and leaf springs and body are con length of the chord or string which may be altered nected by pins or tenons in that, after adjustment by means ofthe ends or. grips 5. By shifting the. has been vperfected, leaf springs and body are drilled, whereupon a pin is introduced into the bore hole; After the adjustment of the support bolts ,4 in the same sense the centerofithe. mirror may be alinedrwith theoptical axis. ,However, it is by .no means necessary to make the clamp- 75. 3 2,104,170 ing or ‘securing means for the mirror symmetric. In fact, in some instances it may be preferable to fasten one end of the string in a leaf spring, and to render the opposite end adjustable. When the proper position for the center of the mirror has been ascertained, care is required to orientate the face of the mirror properly with respect to the chord acting as the axis of rotation. This may here be effected by turning the bolts in the clamp 10 ing device. After also this setting has been ac complished, then the bolts are locked by a screw provided in the supporting system. The bar maget 9 has a central bore which pro vides room for a tongue l3 which is fastened on 15 the supporting system 3. The lower end of the tongue is oscillated under the in?uence of the changing magnetic ?eld between the pole-shoes I4 of a ring magnet l5. This alternating ?eld is created by the signal volume or amplitude re~ 20 sponsive currents in a coil IS. The oscillations of the supporting system and thus of the mirror are made possible by the leaf spring supports l'l. These oscillations are damped or deadened not only by the said rubber buffer means between 25 pole-shoe 6 and upright or block 8, but in addi tion damping or buffer means may be inter posed also between the bar magnet 9 and the tongue l3, as indicated at l8. Disposed on the ring magnet I5 is a body l9 30 against which the leaf springs I‘! are clamped by the screws 20. After ?nal adjustment, pin or tenon connection is effected by the aid of pins surface of the optional means, exact adjustment of the mirror face will be insurable in spite of the fact that the device is entirely encased. In lieu of rubber, of course, also other suitable yielding substances may be employed, provided that they involve suf?cient internal friction. I claim: 1. The combination of an assembly comprising a vibratable member, electrical signal responsive means operable to vibrate said member about one 10 axis, resilient means supporting said assembly, and electrical signal volume responsive means coupled to said assembly and operable to vibrate said assembly about another axis. 2. The combination of a galvanometer as 15 sembly comprising an electromagnetic element, a mirror vibratable about one axis in accordance with the energization of said element, an auxili ary electromagnetic element, resilient support ing means interposed between said assembly and 20 said auxiliary electromagnetic element, and cou pling means connected between said assembly and said auxiliary electromagnetic means for moving said mirror about another‘ axis in accordance with the energization of said auxiliary electromag 25 netic element. 3. A signal recording mechanism of the gal vanometer type including a magnetic structure, pole-shoes resiliently supported on said structure, electrical signal responsive coils cooperatively as 30 sociated with said pole members, and a ?exibly supported vibratable member interposed between said pole-shoes. 2|. The leaf springs I1 terminate in knife edges , 4. A signal recording mechanism of the gal at their free ends which engage in the bearing 22 35 of the supporting system. The suporting system 3 is provided with openings 23' through which chords (not shown) are passed for ensuring that the supporting system stop properly bears upon the knife edges. Adjusting and guide screws ‘24 .40 and 25 respectively, are arranged in body IS. The screws are so set that the heads thereof are in a plane which is parallel to that of the face of the mirror I. At the bottom of the case a cover 26 is screwed off, the light valve is ?tted into the case and is fastened on the latter by means of tractile screws 25, and ?nally the bottom 26 is ?tted on again. By tightening or loosening the screws 25, it is feasible to set the face of the mirror ex actly parallel to the ?at surface 21 of the cas ing. Inasmuch as the last-mentioned surface, 50 after inserting, is pressed against a matching vanometer type including a magnetic structure, 35 pole-shoes resiliently supported on said structure and tapered at their opposed ends, electrical sig nal responsive coils cooperatively associated with said pole members, and a ?exibly supported vi- 7 bratable member interposed between said pole shoes. 49 , 5. In a signal recording mechanism, the com bination of electrical signal responsive means in; cluding an electromagnetic structure provided with an opening and a member vibratable about 45 one axis in accordance with the energization of said means, an auxiliary electromagnetic respon sive means coupled to said member through said opening and operable to vibrate said member 50 about another axis. KARL SCHWARZ.