US2491794A - Variable resistance phonograph pickup - Google Patents

Variable resistance phonograph pickup Download PDF

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Publication number
US2491794A
US2491794A US565537A US56553744A US2491794A US 2491794 A US2491794 A US 2491794A US 565537 A US565537 A US 565537A US 56553744 A US56553744 A US 56553744A US 2491794 A US2491794 A US 2491794A
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United States
Prior art keywords
arm
wire
stylus
head
pickup
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US565537A
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English (en)
Inventor
William S Bachman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE479998D priority Critical patent/BE479998A/xx
Priority to FR58189D priority patent/FR58189E/fr
Priority to FR964168D priority patent/FR964168A/fr
Priority to BE475067D priority patent/BE475067A/xx
Application filed by General Electric Co filed Critical General Electric Co
Priority to US565537A priority patent/US2491794A/en
Priority to GB31655/45A priority patent/GB604077A/en
Priority to US638379A priority patent/US2511664A/en
Priority to US638380A priority patent/US2415403A/en
Priority to US725340A priority patent/US2511665A/en
Priority to FR57871D priority patent/FR57871E/fr
Priority to GB2854/47D priority patent/GB642614A/en
Application granted granted Critical
Publication of US2491794A publication Critical patent/US2491794A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R21/00—Variable-resistance transducers
    • H04R21/04—Gramophone pick-ups using a stylus; Recorders using a stylus

Definitions

  • My invention relates to vibration translating devices such as phonograph pickups and more particularly to such devices for translating mechanical vibrations into electrical variations.
  • the moving parts be made as light and as free moving as practicable to minimize damage to the record grooves and to enable the stylus to follow the grooves accurately over the desired range of frequencies of the recorded sounds. It is desirable also to minimize all extraneous sounds or noises and for this purpose the pickup should be designed to have minimum response to mechanica1 resonance effects. Furthermore, if true reproduction of the sound record is to be accomplished, the pickup response curve should be as nearly linear as possible within the desired range of frequencies.
  • Fig. 1 is a. perspective view of a portion of a sound reproducer including a turntable and tone arm provided with a pickup embodying my invention
  • Fig. 2 is an enlarged view of the pickup shown in Fig. 1, with a portion of the casing broken away to show the details of construction of the head;
  • Fig-311 a sectional side elevation of the bee shownin Fig. 2; 1
  • Fig. 4 is a diagram of the electric circuit connections employed with the pickup
  • Fig. 5 is a perspective view of a pickup head embodying a modification of my invention.
  • Fig. 6 is a sectional front elevation view of the head shown in Fig. 5;
  • Fig. '7 is a perspective View of a pickup head embodying a further modification of my invention.
  • Fig. 8 is an enlarged detail view of a portion of Fi Fig. 9 is a perspective view of a pickup head embodying another modification of my invention.
  • Fig. 10 is a perspective view, partly in section, of a further embodiment of my invention.
  • Fig. 11 is an enlarged exploded view of the stylus and support shown in Fig. 10;
  • Fig. 12 is a sectional side elevation of a pickup head illustrating a still further modification of my invention.
  • Fig. '13 is an enlarged bottom plan view of the stylus support of the head in Fig. 12;
  • Fig. 14 is an exploded perspective view of the stylus arm and associated parts shown in Fig. 13.
  • each of the pickups illustrated in the drawings is provided with a fine electrical resistance Wire and an arrangement for straining the wire in proportion to the vibrations of the stylus as it moves over a record sound track.
  • the resistance wires are arranged so that they are never strained to their elastic limitsv and the variation in electrical resistance is directly proportional to the vibrations of the stylus-
  • the stylus arm is a small lightweight resilient cantilever beam and the resistance wire in some of the pickups is secured transversely of the beam and in others it is secured directly to the beam longitudinally thereof; Distortion of the reproduced sounds because of tone arm resonance and other disturbances is minimized by damping arrangements particularly suited to the lightweight cantilever beam construction of the stylus porting cabinet;
  • a pickup for translating into' electrical vibrations the sound vibrations" recorded on a disk record 5 is provided within a casing 5 at the end of the tone arm 3 and electrical connections are made to the amplifying apparatus (not shown) through wires '5.
  • the pickup arranged in the casing 6, which is shown in detail in Figs. 2 and 3, comprises a supporting head 8 which is a block of suitable insulating material.
  • a stylus arm 9 is rigidly secured to the head of a bolt I9 which in turn is securely clamped to the block 8 by a nut Ii tightened against a conducting plate I2.
  • a suitable stylus or stylus point 53 which may be a sapphire or other jewel, is mounted or otherwise provided at the outer end of the arm 9 so that when the stylus moves over the sound track of a record it is displaced laterally and bends the arm 9 as a cantilever beam.
  • a fine resistance wire I4 is secured to the arm 9 and is held under tension by a pair of conducting springs I5.
  • the arrangement is such that the wire is strained by the vibrations of the arm 9 and its resistance varies in proportion to the strain.
  • the wire is wound one and one-quarter times about two insulating posts It which act as snubbers.
  • the wire is secured at its midpoint to the arm 9, as indicated at I6 and the two straight portions on either side between the posts I6 and the arm are the portions of the wire which are strained by the vibration of the arm, the snubbers I6 preventing straining of the upright portions of the wire by the high velocity vibrations of the stylus produced by the record sound track.
  • the tension maintained by the springs I5 is such that the wire I4 is strained to about onehalf its elastic limit so that variations in strain both above and below the initial strain take place, it being obvious that when the arm 9 moves to one side the tension on one portion of the wire increases while that on the other portion decreases.
  • the conducting springs I5 are connected to two of the wires I through suitable clips secured to the head 9 by screws I? which also hold the springs I5 in position, and the third conductor I is connected to the conducting strip I2 by a third screw I1 and is thereby electrically connected directly to the arm 9 through the bolt III.
  • the wire I4 is connected in a balanced electrical circuit as shown in Fig.
  • lhe wire I4 may be made of Nichrome or other suitable material and should be selected to have uniform elasticity and electrical resistance throughout its length.
  • the diameter of the wire may be of the order of one one-thousandth of an inch.
  • the dynamic mass of the cantilever beam or arm 9 may be made very small. The small dynamic mass enables the stylus I3 to follow the sound track readily with minimum possibility of damage and the tone arm may be counterbalanced so that a very small unbalanced weight, say one-half ounce or less, may be provided to hold the stylus in the record groove.
  • the construction of the pickup head illustrated in Figs. 5 and 6 is similar to that of Figs. 2 and 3 and corresponding parts have been designated by the same numerals.
  • the construction differs from that of the first modification in-that the insulating head indicated at 26 is provided with a recess 21 at its forward end and horizontally mounted damping rods 28 are employed instead of the snubbers I6.
  • the rods 28 are slidably mounted in openings in the head 26 on either side of the recess 2'! and the resistance wire I 4 is secured directly to the inner ends of the rods.
  • the rods are maintained under tension by springs 29 which urge them outwardly away from the arm 9, and the electrical connections to the ends of the wire I4 are made through flexible wires 30 connected between the outer ends of the rods 28 and the outer two leads I.
  • the tension of the springs 29 is adjusted to maintain the wire I4 under tension with a strain about half way to the elastic limit in the same manner as the wire I4 in Fig. 2.
  • a viscous liquid is provided to lubricate the engagin surfaces of the rods 28 and the walls of the openings in the head 28.
  • the fluid is selected so that at the velocities of the displacements produced by the vibration of the stylus I3 in a sound track the rods 28 will remain substantially stationary. However, when displacements at lower velocities occur, the rods will move and minimize strain in the wire I4.
  • One suitable liquid for lubricating these bearings is a solution of polymerized isobutylene in mineral oil.
  • an arrangement is provided for locating the portions of the resistance wire which are to be strained in positions longitudinally of the pickup head.
  • is provided with a downwardly opening recess 32.
  • a stylus arm 33 similar to the arm 9 of Figs. 2 and 5 is mounted in the forward end of the head 3
  • the details of con struction of the arm 33 and the bell cranks 35 are clearly shown in Fig. 8.
  • the bell cranks are tied to the arm by a resistance wire 31 and flex with the arm in accordance with its vibrations.-
  • FA spring 39 is secured .-between 1 the back .end wall of. recess. 32 and the-block 36. tomainta'imthe desired ten-'1. 2
  • the :resistance Wire are made-through fiexiblewiresj; connected. to posts 4
  • , at the rear M of the block ;36 and. connected :to theapostsu38 by suitable; wires142; thezwiresrfl preferablyipass under 'aeprotectiveisheet 43::ofi insu1ating material cemented :to' the block 36.
  • the wires' 40- and the 1 post: :34 constitute the I three terminals not the i pickup-:and.are connectewto the three *conductors. "he The two portions :of: the wire 37- between the stylus-arm and theposts 38, therefore, may" be connectediin the electrical circuit of Fig.*-4
  • may be made small and compact and maybe adapted readily-to accommodation-in a slendertone'arm andco bath-as illustrated in" Fig. 1.-
  • Fig. there 1 illustrated a pickup ,which makes it possible to'employ-anormally unstressed resistance Wire which, when" stressed by vibration of the 'stylus, is strainedalternately in tension and in compression: pickup-head '44 of suitable insulating material is provided-'with-"acenhigh ⁇ velocities-that sufllcientliorc'e canrbe developedyto produce-the required 'strain ofi theifine resistance-wire 48; and low velocitydisturbancesldo not produce corresponding resistance changes; The resistancewire.
  • employed-intherpickupi'ot Fig.9 maytbe of the .samemateriaLandvdiam-a (55817125 that employed with the epickupsl-of Figs. e. 2 to 8 inclusive, a. resistance. wire having a .di.- I ameter. of OHEc-OI'iB-w-thOllStIldth of an inch and-1; having uniform .elasticityt. throughout its length beingsuitable for this purpose.
  • The' material 4 9- restricts lateral -movement of the "embedded wireand-*al though the wire constitutes a-long slendercolum n whichwould *re'adilybend up'on' application of: a
  • the insulating material restrictsthis bending under high v'elocity stresses, and,. asa result, the wireis strained-both in com-as pressionxand. in tension. -:Thus,"ifor any-one displacement ofthe stylus arm, the portionsof wire 1 on one sideofsthe arm: is strainedsin compres as.
  • track salt is on1y.-at'- relatively-i.
  • the armu53. has; an upwardly p'r0ject-, 7 ing lug 55 formed at its rear end which is fitted...
  • Wires 59 are secured to thes'ides of the s'tylus'arm 53' and. the 'endsof the wires adjacent the stylus-54 are soldered or otherwise suitably: secured in good electricalcontact with'the arm' 53 as indicatedat 60.
  • the stylus arm 53 bends and the straight portions of the wires 59, which are bonded to the arm, are strained in proportion to the bending of the arm.
  • One portion of the wire is strained in tension and the other in compression durin the bending of the arm and the electrical resistances of the wires are varied accordingly.
  • the resistance portions therefore can be connected in the electricai circuit of- Fig. 4 in the same manner as the variable resistance portions -of the resistance wires of the other pickups described.
  • the stylus arm 53 has been illustrated as having greater depth than width so that there will be little bending of this arm'in the vertical plane.
  • the neutral axis is a line along which there is no strain in the material of the beam, the material on one side being strained in compression and on the other side in tension.
  • the damping arrangement including the pivota1 support of the stylus arm on horizontal and upright axes makes it possible to minimize distortions due to vibrations such as mechanical vibrations of the pickup and associated parts at the resonant frequency of the assembly. Other low frequency vibrations such as those due to unevenness in the surface of the record disk are also damped out. Since the dynamic mass of the stylus is very small, the pickup arm may be mounted with a very small unbalanced weight and the stylus 54 may therefore be made to follow the record groove and trace the record vibrations with accuracy over a wide band of frequencies.
  • the pickup comprises a head 62 constructed of rigid insulating material and provided with a rectangular opening 63 extending from the top to the bottom thereof near the forward end of the head.
  • a rocker block 64 for supporting a stylus arm 65 is pivotally mounted within the recess 63 on a shaft 66.
  • light metal such as aluminum and the size of the block is such that its pivotal movement within
  • the block 64 may be constructed ofv the recess 63 is limited by the walls of the recess.
  • a spring 6! is mounted-in recesses 68 and 69 in the head 62 and block 64, respectively, and biases the block 64 forwardly in a clockwise direction, as viewed in Fig. 12, so that the front end of the block 64 rests against the front wall of the recess 63.
  • a drill hole 10 in the forward wall of the recess 63 is present merely because it is formed during the drilling of the recess 68 in the head at the rear wall of the recess.
  • the arm 65 is mounted on an upright post TI on washers 12 of resilient insulating material such as Pyralin which hold the post in spaced relation to the sides of an upright bore '13 in the rocker block 64.
  • a third washer 14 of Pyralin or other suitable insulating material is provided at the lower end of the post H in an enlarged portion of the upright bore 13.
  • the two washers l2 and the washer 14 provide the desired damping action to suppress undesired vibrations of the stylus arm.
  • the stylus arm 65 is a forwardly extending portion of a resilient bar 15 which extends rearwardly from the post H in a downwardly opening recess 16 in the head 62 and is soldered to the lower end of a conducting metal sleeve H.
  • the rear end of the bar 15 is upturned at 78 and fits within a recess 19 in the head which serves to locate the bar during assembly of the pickup.
  • the portion of the bar 15 between the sleeve H and the post ll is bent sinuously in a horizontal plane, as indicated at 80, to provide a spring which cooperates with the spring 61 to determine the position of the block 64 when the stylus is resting on a record.
  • the stylus or point is indicated at 8
  • the details of construction of the post II and the method of supporting the stylus arm 65 are shown in Figs. 13 and 14.
  • the post is provided with an enlarged lower end 82 of square cross section and having a shoulder 83 of oblong cross section at the top thereof.
  • a diagonal slot 84 in the head portion 82 receives the rod '15 which is secured therein by soldering.
  • a metal shield 85 is secured on top of the head 82 and has an opening 86 of the same oblong shape as the shoulder 83, the shoulder being of the same height as the thickness of the shield 85.
  • the oblong shape of the shoulder holds the shield in the desired position with respect to the stylus arm.
  • the shield 85 is provided with downwardly extending side members 81 which prevent injury to the arm 65 during the handling of the pickup head.
  • Two lengths of fine resistance wire 88 are secured on either side of the stylus arm 65 over a paper insulator 89 shaped, as shown in Fig. 14, to cover the sides of the square head 82 and of the stylus arm 65.
  • the paper insulator 89 is cemented to the block 82 and stylus arm 65 by a suitable resilient insulating cement such as that sold under the trade name Giyptal.
  • the two lengths of resistance wire 88 are secured to metal foil ribbons 90 and the wires, together with the ribbons, are cemented to the sides of the block 82 and arm 65 over the paper insulator 89 with Glyptal or other suitable resilient cement.
  • These wires are similar in all respects to the wires described in connection with the other embodiments of the invention.
  • the forward ends of the Wires 88 are soldered or otherwise suitably secured to the stylus arm 65, as indicated at 9
  • the positions of the wires 88 along the stylus arm 65 are made alike on both sides and preferably the wires lie along the neutral axis of the arm with respect to bending in a vertical plane. This position of the wires minimizes or prevents distortion due to bending of the stylus arm 65 laterally in directions other than the normal direction of vibration of the stylus 8
  • the ribbons 9D areT'c'onnected' bywirs 92 to'ftwo upright sleeves saor the sam'e'construction'as the sleeve 71 and mounted in the head rearwardly of the recess 63.
  • the sleeves 93 are rivetedin position onthe head 62 in the same manner as thesleeve .Ti-an dithe .wires 92 areI'soldered t'ozthe lower ends of the respective sleeves.
  • the three leads indicated at J in Fig. .4 may be connected tothelsleeve i1 and the two sleeves 93 so that-the pickup may be-connectedin thecircuit ofFigl 4in thesame manner as. th'e other pickupsdescribed. above; the operation orthe pickup ofFig. lZ beingZiessentiaHy the same asthat of-the pickup of. Fig. 10.
  • Damping to preventinterferencedue .to' me- :chanical resonance-frequencies of'the pickup and-tone arm is-provided by the resilientswashers I2 and the washer 14. These washers perform the function of theviscouslubricant in'the pickup ofaFig. and:preventtrotation of5theapost 1
  • upon lateral displacement of the stylus arm 65 atthehigh velocities produced by .the; -recorded I .soundtrack.
  • a phonograph pickup comprising a support- 7 .10 i ihgliead, 'astylus arm having 'a-styluslpoint at one .endand beingsupported onMsaid-"heaG at its otherrend wherebysaid -arm is vibrated by vibration-sci.
  • said-stylus point,- an electrical re- 5 'sistance wire havingone of its'ends secured on said headand its other end attached to said farm to be strained by vibrations of 'said-arm toyary the resistance of said wire accordance -with I I vibrations .ofsaid stylus point.
  • a phonograph pickup comprising-a supporting head, 'a resilient stylus armsupported atone end on said head and --having -a stylus point at its othenendadapted to be vibratedupoii movement along a record sound tracktwhereby -isaid arm is stressed as a cantilever beam;- and; an
  • electrical resistance.wire havingone of its'uends secured tosaid head and itsother end' attached to-said. arm to be strained upon bending of said riarm to vary theelectrical resistanceof-saidc-wire 4 in accordance-with the vibrations oi-said stylus 5 point.
  • a phonograph pickup comprising-asupporting head, a stylus arm supported atonecend on -said-head and havinga stylus-point at its other endcadaptedto be vibrated upon movement along a recordsound track, and an-electr-ical resistance Wire-r--ha ving its .ends connected respectively to said-arm and to said headsaid wire beingstrained by the vibrations of said arm to Y varyw-thewelec- 5 trical resistance of saidwire accordance with the vibrations -of said arm.
  • a phonograph pickup comprising rag-supportinghead; a stylus arm supported ati-oneriend on-saidhead and having a stylus: point at its other end adapted to be vibrated upon movement along .a .-record -sound-.-track;. an felectricar resistance wire having ca point mechanically: connected to said arnnand :means including-arresilient member mounted on said head and connected to another point of said wire for tensioning said wire between said head and said arm whereby said wire is strained in accordance with the vibrations of said arm and the electrical resistance of said wire is varied in proportion to 55 such vibrations.
  • a phonograph pickup comprising a supporting head, a stylus arm supported at one end on said head and having a stylus point at its other end adapted to be vibrated upon movement along a record sound track, and an electrical resistance wire having its ends mechanically connected to said head and its midportion mechanically connected to said arm to provide portions of said wire on either side of said arm, said portions be ing oppositely strained mechanically by vibrations of said arm whereby the electrical resistances of said portions of said wire are varied oppositely in proportion to the vibrations of said arm.
  • a phonograph pickup comprising a supporting head, a stylus arm supported at one end on said head and having a stylus point at its other end adapted to be vibrated upon movement along a record sound track, an electrical resistance wire mechanically connected to said arm, resilient means on said head for holding said wire under tension and for affording bodily movement of said wire with said arm, and means for damping high velocity movements of said resilient means whereby said wire is strained in accordance with vibrations of staid stylus point produced by a record sound track and the electrical resistance of said wire is varied in proportion to such vibrations.
  • a phonograph pickup comprising a supporting head, a stylus arm supported at one end on said head and having a stylus point at its other end adapted to be displaced laterally upon movement along a record sound track, a member movably mounted on said head, an electrical resistance wire connected to said arm and to said member, resilient means connected between said member and said head for holding said wire under tension and for affording movement of said wire bodily with said arm, and a coating of viscous fluid between said member and said head for damping high velocity movements of said member whereby said wire is strained in accordance with vibrations of said stylus point produced by a record sound track and the electrical resistance of said wire is varied in proportion to such vibrations.
  • a phonograph pickup comprising a supporting head, a stylus arm supported at one end on said head and having a stylus point at its other end adapted to be vibrated upon movement alond a record sound track, a pair of rods slidably mounted in said block one on either side of said arm, an electrical resistance wire having its midportion connected to said arm and its ends contions of said stylus point produced by a record sound track and the electrical resistance of said wire is varied in proportion to such vibrations.
  • a phonograph pickup comprising a supporting head, a stylus arm supported at one end on said head and having a stylus point at its other end adapted to be vibrated upon movement along a record sound track, a crank rigidly s cured to said arm adjacent said head to form bell crank with said arm, an electrical resistant wire connected to said crank, and means inclut ing a resilient member on said head for tensior ing said wire between said head and said crar and in a direction longitudinally with respect 1 said arm whereby said wire is strained upo vibration of said stylus point and the electric: resistance of said wire is varied in accordam with such vibrations.
  • a phonograph pick-up comprising a strai responsive resistance wire mounted betwee spaced apart supports, and a phonograph styli connected to the midpoint of said wire for vary ing the strain in the two halves of said wire 1' accordance with a phonograph record.
  • An apparatus for reproducing phonograp records comprising a, tone arm having space apart supports, a strain responsive resistanc wire connected between spaced apart supports said tone arm, a stylus connected to the midpoix of said wire, a transformer having a center tappe primary Winding, a source of potential connecte between the center tap of said winding and sai phonograph stylus, and means connecting th outer extremities of said transformer winding t the outer extremities of said wire.
  • a phonograph pick-up comprising a strai responsive resistance Wire connected betwee: spaced apart supports, a phonograph stylus con nected to the midpoint of said wire, and mean for balancing the tension in the two halves c said wire.
  • An apparatus for reproducing phonograpl records comprising a tone arm having trans versely arranged spaced apart supports, a straii responsive resistance wire connected betwee] said supports, a phonograph stylus connected it the midpoint of said Wire, a bridge circuit in cluding an inductive impedance connected to th outer extremities of said wire and said phono graph stylus, said circuit including a source 0 direct current connected between said stylus am the midpoint of said impedance.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Electrophonic Musical Instruments (AREA)
  • Supporting Of Heads In Record-Carrier Devices (AREA)
  • Tone Control, Compression And Expansion, Limiting Amplitude (AREA)
  • Frying-Pans Or Fryers (AREA)
  • Springs (AREA)
  • Adjustable Resistors (AREA)
US565537A 1944-11-28 1944-11-28 Variable resistance phonograph pickup Expired - Lifetime US2491794A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
BE479998D BE479998A (en)van) 1944-11-28
FR58189D FR58189E (en)van) 1944-11-28
FR964168D FR964168A (en)van) 1944-11-28
BE475067D BE475067A (en)van) 1944-11-28
US565537A US2491794A (en) 1944-11-28 1944-11-28 Variable resistance phonograph pickup
GB31655/45A GB604077A (en) 1944-11-28 1945-11-23 Improvements in and relating to vibration translating devices
US638379A US2511664A (en) 1944-11-28 1945-12-29 Phonograph pickup
US638380A US2415403A (en) 1944-11-28 1945-12-29 Vibration translating device
US725340A US2511665A (en) 1944-11-28 1947-01-30 Hum eliminating circuit for phonograph pickups
FR57871D FR57871E (fr) 1944-11-28 1947-12-16 Perfectionnements aux pick-up électriques
GB2854/47D GB642614A (en) 1944-11-28 1948-01-30 Improvements in and relating to pick-ups of the variable resistance type

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US565537A US2491794A (en) 1944-11-28 1944-11-28 Variable resistance phonograph pickup
US638380A US2415403A (en) 1944-11-28 1945-12-29 Vibration translating device
US725340A US2511665A (en) 1944-11-28 1947-01-30 Hum eliminating circuit for phonograph pickups

Publications (1)

Publication Number Publication Date
US2491794A true US2491794A (en) 1949-12-20

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US565537A Expired - Lifetime US2491794A (en) 1944-11-28 1944-11-28 Variable resistance phonograph pickup
US638380A Expired - Lifetime US2415403A (en) 1944-11-28 1945-12-29 Vibration translating device
US725340A Expired - Lifetime US2511665A (en) 1944-11-28 1947-01-30 Hum eliminating circuit for phonograph pickups

Family Applications After (2)

Application Number Title Priority Date Filing Date
US638380A Expired - Lifetime US2415403A (en) 1944-11-28 1945-12-29 Vibration translating device
US725340A Expired - Lifetime US2511665A (en) 1944-11-28 1947-01-30 Hum eliminating circuit for phonograph pickups

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US (3) US2491794A (en)van)
BE (2) BE475067A (en)van)
FR (3) FR57871E (en)van)
GB (2) GB604077A (en)van)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2545737A (en) * 1947-11-01 1951-03-20 Goodrich Co B F Variable resistance pickup element
US2568673A (en) * 1946-09-19 1951-09-18 Admiral Corp Resistance-type phonograph pickup
US2648726A (en) * 1949-09-02 1953-08-11 Harry C Warner Control device for electrical circuits
US2744181A (en) * 1953-04-21 1956-05-01 Boeing Co Extensometers
US3005170A (en) * 1959-09-08 1961-10-17 Budd Co Printed-circuit type lead wire connectors
US3030454A (en) * 1956-11-13 1962-04-17 Western Electric Co Magnetostrictive type phonograph pickup and system embodying the same

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2482467A (en) * 1946-05-10 1949-09-20 Westinghouse Electric Corp Phonograph pickup
US2507188A (en) * 1947-05-13 1950-05-09 Herbert K Neuber Electrostatic phonograph pickup
US2578809A (en) * 1948-01-07 1951-12-18 Admiral Corp Phonograph pickup
US2680012A (en) * 1948-01-26 1954-06-01 Eberbach Corp Analytical balance
US2670407A (en) * 1949-02-17 1954-02-23 Magnavox Co Drive system for crystal pickups

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Publication number Priority date Publication date Assignee Title
US1757547A (en) * 1929-06-12 1930-05-06 Ruben Samuel Phonograph pick-up
US2148013A (en) * 1936-03-02 1939-02-21 Roy W Carlson Stress meter
US2252464A (en) * 1937-12-06 1941-08-12 United Aircraft Corp Stress measuring means
US2359245A (en) * 1943-01-19 1944-09-26 Gulf Research Development Co Electrical displacement vibrometer
US2373676A (en) * 1941-07-30 1945-04-17 Kenneth J Germeshausen Reproducer

Family Cites Families (3)

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Publication number Priority date Publication date Assignee Title
US1432022A (en) * 1916-10-11 1922-10-17 Western Electric Co Circuit connection of electron discharge apparatus
US1917728A (en) * 1928-03-30 1933-07-11 Rca Corp Discharge tube cathode energizing
US2380514A (en) * 1940-06-12 1945-07-31 Germeshausen Kenneth Joseph Vibration-translating device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1757547A (en) * 1929-06-12 1930-05-06 Ruben Samuel Phonograph pick-up
US2148013A (en) * 1936-03-02 1939-02-21 Roy W Carlson Stress meter
US2252464A (en) * 1937-12-06 1941-08-12 United Aircraft Corp Stress measuring means
US2373676A (en) * 1941-07-30 1945-04-17 Kenneth J Germeshausen Reproducer
US2359245A (en) * 1943-01-19 1944-09-26 Gulf Research Development Co Electrical displacement vibrometer

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2568673A (en) * 1946-09-19 1951-09-18 Admiral Corp Resistance-type phonograph pickup
US2545737A (en) * 1947-11-01 1951-03-20 Goodrich Co B F Variable resistance pickup element
US2648726A (en) * 1949-09-02 1953-08-11 Harry C Warner Control device for electrical circuits
US2744181A (en) * 1953-04-21 1956-05-01 Boeing Co Extensometers
US3030454A (en) * 1956-11-13 1962-04-17 Western Electric Co Magnetostrictive type phonograph pickup and system embodying the same
US3005170A (en) * 1959-09-08 1961-10-17 Budd Co Printed-circuit type lead wire connectors

Also Published As

Publication number Publication date
GB604077A (en) 1948-06-28
FR964168A (en)van) 1950-08-08
FR57871E (fr) 1953-09-18
US2511665A (en) 1950-06-13
BE475067A (en)van)
GB642614A (en) 1950-09-06
BE479998A (en)van)
FR58189E (en)van) 1953-09-29
US2415403A (en) 1947-02-11

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