US2418541A - Reversible drive for a magnetic recording medium - Google Patents
Reversible drive for a magnetic recording medium Download PDFInfo
- Publication number
- US2418541A US2418541A US511253A US51125343A US2418541A US 2418541 A US2418541 A US 2418541A US 511253 A US511253 A US 511253A US 51125343 A US51125343 A US 51125343A US 2418541 A US2418541 A US 2418541A
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- wire
- switch
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- conductor
- magnetic recording
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- 230000002441 reversible effect Effects 0.000 title description 5
- 239000004020 conductor Substances 0.000 description 26
- 238000004804 winding Methods 0.000 description 16
- 230000007246 mechanism Effects 0.000 description 9
- 230000005298 paramagnetic effect Effects 0.000 description 7
- 238000000034 method Methods 0.000 description 5
- 229910052754 neon Inorganic materials 0.000 description 5
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- 230000007935 neutral effect Effects 0.000 description 4
- 238000003199 nucleic acid amplification method Methods 0.000 description 4
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000005415 magnetization Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- 229910000677 High-carbon steel Inorganic materials 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
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- 230000004907 flux Effects 0.000 description 1
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- 230000001788 irregular Effects 0.000 description 1
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- 150000002806 neon Chemical class 0.000 description 1
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Images
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
- G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
- G11B15/44—Speed-changing arrangements; Reversing arrangements; Drive transfer means therefor
- G11B15/442—Control thereof
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
- G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
- G11B27/34—Indicating arrangements
Definitions
- This invention relates to a magnetic recorder, and more particularly to an electromagnetic instrument for recording sound on a paramagnetic wire or tape and reproducing the sound therefrom.
- Electromagnetic recording and reproduction of sound vibrations, speech, etc. dates back to the end of the nineteenth century, and While some improvements and refinements have been made since that time, in both the method and apparatus, Vsuch improved apparatus and methods have not been utilized to any great extent commercially. There are a number of reasons for this, the most important of which are probably the inherent limitations in the apparatus heretofore proposed. In general, the volume level of the reproduced signals of previous systems was low, the frequency range covered was very limited, the extraneous noise was objectionable and the distortion of the wave forms were often o! such character and magnitude as to render the reproduction of extremely low quality and at times almost unintelligible.
- a further object of the present invention is to provide a novel unitary apparatus for magnetic recording and reproduction including a recording head, reel means for carrying and moving a paramagnetic Wire or tape to the recording head, an electric amplier and a loud speaker.
- a still further object of the present invention is to provide novel indicating means for indicating the position of, recorded sound vibrations on a paramagnetic wire or tape.
- a still further object of the present invention is to provide novel means for shifting from a position for magnetic recording to a position for magnetic reproduction on a paramagnetic wire or tape.
- the present invention is to provide novel means for reeling and unreeling a paramagnetic wire or tape in the recording and reproducing apparatus.
- Still another object of the present invention is to provide novel means for stopping the reels at any desired selected portions of therecording or reproduction.
- Still another object of the present invention is to provije a novel method and means for braking the wire carrying reels.
- Figure 1 is a front viewof one embodiment of the present invention, as viewed in a plane indicated by theline I-I of Figure 2;
- Figure 2 is an end sectional view through the apparatus, as taken along the line II-II of Figure 1; v
- Figure 3 is an irregular sectional view of the apparatus, as taken along the line III--III of Figure 2; Y
- Figure 4 is a diagrammatic illustration of the control switch and the wire position indicating mechanism
- Figure 5 is a view taken along the line Figure 3;
- Figure 6 is a view taken along the line VI-VI of Figure 3.
- Figure '1 is an electric circuit diagram ofthe 1 system.
- FIGs 1 to 3 of the drawings there is illustrated a magnetic recorder and reproducer constructed in accordance with the teachings of the present invention. All of the essential component parts of my recorder and reproducer, with the exception of the microphone and a source of power, are contained in a single unit illustrated.
- This unit as illustrated in Figures 1 to 3, includes a housing member I0 having a base Il, a top wall I2 and an inclinedfront panel I3.
- Thev inclined front panel I3 includes a lower portionv 'I4 and an upper portion I5 which is offset rearwardly from the lower portion I 4.
- a magnetic recording head I6, an erasing head I1, a recording medium I8 in the form of a wire, and a pair of reels I9 and 20, are all mounted on the outer face of the upper panel I on the front wall I3.
- Reels I9 and 28 are mounted for rotation on shafts 2
- the reel I9 is the supply reel and the reel 20 is the receiving or windup reel, the reel 20 being driven in a counter-clockwise direction as viewed in Figure l.
- the wire is to be rewound onr ment presently to be described which is housed within the casing I6 and behind the front panel I3.
- the record medium or wire I8 is preferably vmade of a high carbon steel and, by way of example, may conveniently have a diameter of approximately .005 inch.
- This wire I8 is threaded through the erasing head I1 which, as will presently be explained. completely demagnetizes the wire and removes any magnetism therefrom, whether caused from previous records made on the wire, or from any extraneous source.
- the wire I8 then passes around a guide pulley 23,
- is provided in the housing Il! and is arranged to be selectively connected to either the shaft 2
- is preferablv mounted in an vinclined position, as shown in Figure 2, with its drive shaft 32 extending substantially perpendicular to the panel portion I4.
- may be ⁇ conveniently mounted on a bracket 33 which is ,secured to the base II, as at 34. and to the motor as at 35.
- an opening 36 is provided in the base I I into which the casing of the motor extends. but does not completely pass therethrough. This opening 36 is provided as a. Ventilating opening.and facilitates circulation of air around the motor and the amplifying equipment presently to be described.
- Drive pulleys 31 and 38 are mounted on the shafts 2
- the shafts 22 and 2I pass through the panel portion I5 and then through the skeleton frame structure 39 and 39', respectively; each of which includes a back plate 40 and a plurality of spacer plates 4
- These structures 39 and 39 are associated with each of the shafts 22 and 2
- the structure 39, which is associated with the shaft 22 is shown in detail in Figures 5 and 6.
- the shaft 22 is mounted in bushings 25
- a worm 256 which meshes with a worm wheel 251 mounted on a shaft 258 which extends substantially at right angles not only to the shaft 22 but also to the shaft 255.
- the shaft 258 is mounted on two of the spacer members 4I on opposite sides of the skeleton structure 39.
- Mounted on one end of the shaft 258 is a. heartshaped cam 259 which is arranged to engage a cam follower 260 which is in the form of an inverted L-shaped finger which is secured to a rod 26
- the end of the cam follower 268 projects through a slot 262 in the spacer member 4
- a biasing spring 265 in the form of a resilient Wire having several turns inthe center is secured at one end of the back plate 48 of' the skeleton frame ⁇ structure 39 associated 'with the shaft 2
- a pair of do'g leg levers 46 and 41 are pivotally mounted as at 48 and 49 to a bracket 50 which is secured to the rear end wall of the motor 3
- the dog leg levers 46 and 41 each have downwardly projecting legs 52 and 53 respectively, on which is pivotally mounted driving pulleys 54 and 55, respectively.
- Drive pulley 54 is associated and mechanically coupled to a friction roller 56
- drive pulley 55 is associated with and mechanically coupled to a friction roller 51.
- Fixed to the motor drive shaft 32 is a friction roller 58 against which friction roller 56 and friction roller 41 are selectively arranged to be moved into driving contact.
- a flexible drive cable 59 extends around drive pulleys 54 and 31.
- a flexible drive cable 60 extends around drive pulleys 55 and 38.
- the friction roller 58 is in driven engagement with they drive roller 58, and, accordingly, the shaft 2
- 'Ihis in turn causes reel I9 to be driven in a counterclockwise direction as viewed in Figure 1, and accordingly the wire I8 is being unwound from the reel 28 and rewound on the' reel I9.
- the friction roller 56 is moved out of engagement with the friction roller 58 and the friction roller 51 is moved into engagement with the friction roller 58 the shaft 22 is driven by the motor 3
- the dog leg levers 46 and" have upwardlyv extending bent leg portions 6
- a ringer 63 extends between the two upstanding legs 6I and 62 and is arranged to be moved by the motor control operating handle 64.
- Thearm A6.3 is pivotally mounted on a bracket 65, as at 6-5', which is supported on a frame construction 66 mounted on the rearv of the lower panel portion I4.
- the motor control operating handle 64 is pivotally mounted on the subframe member -66 as at 61.
- the motor control 64 determines Whether the motor is causing the wire I8 to be moved in a recording and reproducing direction through the recordinghead I6, or whether the motor is causing the wire I8 to be rewoundon reel I9.
- the handle 64 is thrown to the right as viewed in Figure 1 or downwardly as viewed in Figure 4, the wire I8 is moving in a recording and reproducing direction (i. e., it is being wound up on reel 28).
- the handle 64 is thrown to the left as viewed in Figure 1 or upwardly (as shown) in Figure 4
- the wire I8 is moving in a rewinding direction (i. e., it is being rewound on reel I9).
- the handle 64 When the handle 64 is in an intermediate or central position, the wireis stationary and the motor 3
- the amplifying equipment 69 is mount ⁇ ed to the rear of and around the motor ⁇ 3
- a loud speaker 18 is mounted on the lower panel portion I4.
- the left portion of the lower panel I4 contains an opening 1
- Control knob 13 is a volume control
- control knob 14 is an on-and-ofl switch, as well as the tone control
- control knob 15 determines whether the electrical circuit will operate as a recorder or as a reproducer.
- To the left of control knob 15 is a red light 16 which is lit when the control knob 15 is moved to a. Dosition for operating the apparatus as a recorder.
- a green light 11 is located to the right of the control knob 15 and is lit when the control knob 15 is moved to a position for causing the apparatus to operate as a. reproducing unit.
- a neon bulb 18 is located above the control knob 15 and, as will presently be explained, indicates the proper volume setting when the apparatus is operated as a recorder.
- the motor control 64 is located on the front of the panel portion I4, as shown in Figure 1, while the indicating means 43 is located to the left thereof.
- the electrical circuit of the apparatus is diagrammatcally shown in Figure 7.
- the electrical circuit in general includes the magnetic recording head and the audio amplier, a loud speaker and microphone plug which is ⁇ arranged to be connected to any suitable type of microphone. With the switch connections as shown in Figure 7, the apparatus is in a position for reproducing sound vibrations which have previously been recorded on the wire
- the magnetic recording headV includes a coil 19 which is magnetically associated with the wire I8 or, in other words, it is so related to the wire I8 that the lines of flux produced by the magnetized wire will intersect the windings of the coil 19.
- the wire I8 passes ldirectly through the tapered pole portion 88 of a laminated iron core member 8
- the coil 19 is connected to theinput grid electrode 82 of the first audio ampliiier tube 83 through a shielded conductor 84 (the shield being indicated by the broken lines 85).
- the other side of the coil 19 is connected to the cathode 86 of the electron discharge device 83 through the conductor 81.
- the cathode 86 and the conductor 81 is grounded.
- Two switches 89 and 98 are connected in the circuit of conductor 84. Interposed between the switch 98 and the grid electrode 82 is a bias cell 9
- the electron dis'charge'device 83 may 'be of any suitable type for use in an audio amplier and as shown 'is of the multigrid type.- More particularly, the electron discharge device 83, in addition to the input grid electrode 82 andthe cathode 86, includes a heating filament 93, a screen grid electrode 94, a suppresser grid ,electrodel 95 and an anode 96.
- a second stage of amplification is provided by an electron discharge device 91 which is connectedby a capacity coupling 98 to the output circuit of the electron discharge de-
- the electron discharge device 91 is similar to' the electron dischargedevice 83 andincludes, in addition to the grid electrode
- 82 is providedv with avselfbiasing resistor
- is con- ⁇ 7
- 05 are connected to the circuit in the conventional manner, the screen grid
- the anode-cathode circuit of the electron discharge device 91 is provided with aby-pass condenser lI and a variable tone control resistor III which are connected between the anode
- 06 is also connected through a couplingl condenser H2 to the input grid electrode H3, of an output or power tube
- 5 is connected between the grid electrode
- 4, in addition to the grid II3, includes a filament II6, a cathode
- the suppresser grid I I9 is directly connected to the cathode
- 1 is connected through a self-biasing resistor
- This neon lamp circuit includes a condenser
- the neon lamp 18 is connected between the grounded conductor 81 and the movable element
- 4 is connected to an output transformer
- 26 is connected between the anode
- 26 has its opposite end connected to an output jack
- 26 is connected to the grounded conductor 81 and also to a contact point
- 32 is connected to a second contact point
- 34 is connected through switch
- in the position shown in Figure 7 of the drawing, the speaker
- 38 are connected to a shorting switch (not shown), which is arranged to be closed when the unit is being rewound.
- 39 which includes a power transformer
- 40 is connected through a plug
- 43 is connected between plug
- 44 is preferably combined with the tone control and operated from a single knob 14 ( Figure 1).
- 45 is arranged to be connected to the filaments 93,
- 48 indicate diagrammatically that they are arranged to be connected to the arrows on the iilament elements referred to.
- 46 supplies power to the cathode
- 5I are connected to opposite ends of the winding
- 48 are both grounded through a conductor
- 56 are connected in the circuit as shown, while an inductive reactance element
- 59 are also provided and are connected vin a conventional manner. It is to be understood that the circuit arrangement above described is a conventional full wave rectifler circuit for supplying the desired potential to the various elements of the audio amplifier.
- the desired positive potential for anode 96 and screen grid 94 of tube 83 is obtained through conductor
- 03 of tube 91 is obtained through conductor
- 4 is obtained through conductor
- the red pilot light 16 and the green pilot light 11 are energized directly from the secondary winding
- the green pilot'l light is in a state of energization and, as has previously been mentioned, this indicates that the circuit is arranged to reproduce sound vibrations magnetically recorded onthe recording medium I8.
- Suchan oscillator is diagrammatically illustrated in Figure '1 and includes an electron discharge device or oscillator tube
- 16 is provided.
- 16 are connected at one end to the anode
- the lower end of the tuned circuit is also connected through a conductor
- is provided between the control grid
- 10 is connected through a condenser
- 83 is arranged to be connected through a switch
- 86 is a lter circuit including a plurality of inductance elements
- 86 is arranged to be connected through a switch
- is connected to a condenser
- 68 and its associated circuits are employed only when the equipment is being employed as a recorder.
- the oscillator is cut out of the circuit in a manner which will be readily apparent from an inspection of the drawings.
- 80 of the oscillator circuit to the recording head I6, are all arranged to be moved from their full line position as shown in Figure 7, to their dotted line position as shown in Figure 7 when it is desired to operate the equipment as a recorder rather than as a reproducer.
- 94 are all preferably mounted as a gang switch for operation by the control switch ( Figure 1), which control switch or lever, as previously described, also controls the direction of rotation of the reels I9 and 20.
- a microphone is connected through a suitable lead (not shown) to the microphone plug
- the output of the audio amplifier is connected to the equalizer
- 66 is also fed through a coupling condenser I 19 to the same input conductor
- 99 is con nected directly to the input circuit of the second stage of audio amplification as represented by the tube 91. More particularly, the contact 200 is connected to the upper end of the potentiometer 99, which in turn is connected through a movable contact 20
- 99 is connected to the grounded conductor 81 through a conductor 203. This arrangement may be conveniently used to record incoming radio programs or the like directly on the record medium I6.
- the rst stage of amplification in the audio amplier is skipped, when it is desired to record an incoming radio program, or the like, by connecting the outputof the radio (not shown) to the jack
- 21 which has previously been described, is provided in the equipment for the purpose of using a separate and larger loud speaker (not shown), if desired, when the equipment is being operated as a reproducer.
- 61 connects the green light 11 to the energizing winding
- 61 When the switch
- the shaft 204 extends out of the counter mechanism 43 and carries on the end thereof a cam cylinder 205 which has a transverse groove 206 therein immediately followed by a transverse raised portion 201.
- An arm 208 is pivotally mounted for movement about the point 209 and is spring biased by a coil spring 2
- the right-hand end of the member 208 is provided with a cam engaging portion or protuberance 2
- a link member 2 l2 extends to the inner end yof the switch arm 64 where the inner end of the switch arm 64 engages the forked end 2
- 2 is pivotally mounted to the inner end of the switch arm 64 as at 2
- 2 is bent as at 2
- Th'e cam cylinder 205 is arranged to rotate very slowly so that one revolution thereof substantially represents the entire linear movement of the wire or record medium I8. More particularly, the transverse groove 206 and the transverse raised portion 201 are arranged to be engaged by the cam follower 2
- the abutment portion 2li would be in engagement with the lend 2I1 of the arm 200.
- strikes the raised portion 201 it will cause the left-hand portion 2l1 of the arm 208 to be pressed against the abutment 2li to force the switch 04 to its neutral position. It will be observed that if the cam follower 2li strikes the groove 2
- a support including a casing having a panel and a base, a recording and reproducing electromagnetic head mounted on said panel, a long paramagnetic wire or tape, a pair of reels rotatably mounted on said panel for rotation about axes extending substantially perpendicular to said panel and oniwhich the ends of said wire l2 or tape are disposed and around which the bulk of said wire or tape is wound, said head being disposed to have said wire or tape pass therethrough, a motor mounted on said support and having a friction driving drum, a pair of levers rockably mounted in proximity to said motor and each having a friction drum to be driven rotatably mounted thereon, said driven drums being disposed on opposite sides of said driving drum,Y 10 spring means urging said driven drums into frictional engagement with lsaid driving drum, control means for selectively moving one or the otherY of said members to move its associated driven drum out of engagement with said driving drlmi,
- either of said driven drums may be selectively retained in driving engagement with said driving member, and means coupling said driven drums to said reels respectively for rotatably driving said reels.
- a magnetic recording unit a supporting structure, a recording electromagnetic head mounted on said structure, a long paramagnetic wire or tape, a pair of reels rotatably mounted on said structure and on which the ends of said wire or tape are disposed and around which the bulk of said wire or tape is wound, said recording head being disposed in magnetizing relation to said wire or tape, driving means mounted on said structure and having a friction drive drum,
Landscapes
- Recording Or Reproducing By Magnetic Means (AREA)
Description
April 8, 1947. M. cAMRAs 2,418,541
REVERSEIBLE DRIVE FOR A MAGNETI RECORDING MEDIUM Filed Nov. 22, 1943 5 sheets-sheet 1 All ul.
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new l l by ff @E April ,v 1947. M CAMRAS, 2,418,541
REVERSIBLE DRIVE FOR A MAGNETIC RECORDING MEDIUM Filed Nov. 22, 1943 5 Sheets-:Sheet 2 n MARY/U CAME/as" 7 f f f/i 5- April 8, 1947. M. cAMRAs 2,418,541
REVERSIBLE DRIVE FOR A MAGNETIC RECORDING MEDIUM Filed Nov. 22, 1943 5 Sheets-Sheet 3 .l as "VI u a9 I ,9 Q5 g I o 45 2&3 I 22. n l o 2 37 ef. 4: 26 G, a 42. 9 26h 4/ l t J 5s I (a n 4s a z 47 4 70 Q l 48 ,gf l y r 5./ 49 l, E
I 50 i" 5 l; 2 54:2 x I 5 3l f 1 m 4 Z/a Il 4, l Il I I llllll 2,; EEE lll//l/l//lllllllll ./V//f/V UIL M42 WU @AMBAS April 8, 1947. M, CAMRAS 2,418,541
REVERSIBLE DRIVE FOR A MAGNETIC RECORDING MEDIUM Filed Nov. 22, 1943 5 sheets-sheet 4 MAew/u Cfr/viens I l A 5y f f 52225 April s, 1947.
5 sheets-sheet S Filed Nov. 22, 1943 lv/ CN Mnewu -CA Mens Patented Apr. 8, 1947 REVERSIBLE DRIVE FOR A MAGNETIC RECORDING MEDIUM Marvin Camras, Chicago, lll., assignor to Armour Research Foundation, Chicago, Ill., a corporation of Illinois Application November 22, 1943, Serial No. 511,253
2 Claims. 1
This invention relates to a magnetic recorder, and more particularly to an electromagnetic instrument for recording sound on a paramagnetic wire or tape and reproducing the sound therefrom.
Electromagnetic recording and reproduction of sound vibrations, speech, etc., dates back to the end of the nineteenth century, and While some improvements and refinements have been made since that time, in both the method and apparatus, Vsuch improved apparatus and methods have not been utilized to any great extent commercially. There are a number of reasons for this, the most important of which are probably the inherent limitations in the apparatus heretofore proposed. In general, the volume level of the reproduced signals of previous systems was low, the frequency range covered was very limited, the extraneous noise was objectionable and the distortion of the wave forms were often o! such character and magnitude as to render the reproduction of extremely low quality and at times almost unintelligible.
In a co-pending application of mine, entitled Method and means of magnetic recording, illed December 22, 1941, Serial No. 423,928, now Patent No. 2,351,004, issued Junee 13, 1944, and assigned to the same assignee as the present invention, a novel system of magnetic recording is described and claimed. The present invention is directed to a novel application of the method and means described and claimed in said copending application, and to a novel combination of elements employed therewith.
4 This particular application is a division of my co-pending application entitled Magnetic recorder, U. S. Serial No. 452,419, filed July 27, 1942, now Patent No. 2,351,005, issued June 13, 1944, and assigned to the same assignee as the present invention.
It is an object of the present invention to provide a novel apparatus for magnetic recording and reproduction.
A further object of the present invention is to provide a novel unitary apparatus for magnetic recording and reproduction including a recording head, reel means for carrying and moving a paramagnetic Wire or tape to the recording head, an electric amplier and a loud speaker.
A still further object of the present invention is to provide novel indicating means for indicating the position of, recorded sound vibrations on a paramagnetic wire or tape.
A still further object of the present invention is to provide novel means for shifting from a position for magnetic recording to a position for magnetic reproduction on a paramagnetic wire or tape.
`.Another and still further object oi the present invention is to provide novel means for reeling and unreeling a paramagnetic wire or tape in the recording and reproducing apparatus.
Still another object of the present invention is to provide novel means for stopping the reels at any desired selected portions of therecording or reproduction.
Still another object of the present invention is to provije a novel method and means for braking the wire carrying reels.
The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and manner of construction, together with further objects' and advantages thereof, may best be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
Figure 1 is a front viewof one embodiment of the present invention, as viewed in a plane indicated by theline I-I of Figure 2;
Figure 2 is an end sectional view through the apparatus, as taken along the line II-II of Figure 1; v
Figure 3 is an irregular sectional view of the apparatus, as taken along the line III--III of Figure 2; Y
Figure 4 is a diagrammatic illustration of the control switch and the wire position indicating mechanism;
Figure 5 is a view taken along the line Figure 3;
Figure 6 is a view taken along the line VI-VI of Figure 3; and
Figure '1 is an electric circuit diagram ofthe 1 system.
In Figures 1 to 3 of the drawings, there is illustrated a magnetic recorder and reproducer constructed in accordance with the teachings of the present invention. All of the essential component parts of my recorder and reproducer, with the exception of the microphone and a source of power, are contained in a single unit illustrated. This unit, as illustrated in Figures 1 to 3, includes a housing member I0 having a base Il, a top wall I2 and an inclinedfront panel I3. Thev inclined front panel I3 includes a lower portionv 'I4 and an upper portion I5 which is offset rearwardly from the lower portion I 4.
A magnetic recording head I6, an erasing head I1, a recording medium I8 in the form of a wire, and a pair of reels I9 and 20, are all mounted on the outer face of the upper panel I on the front wall I3. Reels I9 and 28 are mounted for rotation on shafts 2| and 22. When the apparatus is being operated as a recorder or reproducer, the reel I9 is the supply reel and the reel 20 is the receiving or windup reel, the reel 20 being driven in a counter-clockwise direction as viewed in Figure l. When the wire is to be rewound onr ment presently to be described which is housed within the casing I6 and behind the front panel I3. v
The record medium or wire I8 is preferably vmade of a high carbon steel and, by way of example, may conveniently have a diameter of approximately .005 inch. This wire I8 is threaded through the erasing head I1 which, as will presently be explained. completely demagnetizes the wire and removes any magnetism therefrom, whether caused from previous records made on the wire, or from any extraneous source. The wire I8 then passes around a guide pulley 23,
' which is mounted for free rotation on the shaft 24, and held in place by a lock nut 25. 'I'he wire is thereafter passed through the magnetic recording head I6, which will presently be explained in detail. The wire I8, after leaving the recording head-I6, passes around a guide pulley 26, which is freely mounted on a shaft 21, and held in'pla'ce by a lock nut 28. The wire I8 finally passes to the takeup reel 20. A pair of level winding guide nngers 29 and 30 are preferably provided to assure an even distribution of the wire on the reels I9 and 28. K
A motor 3| is provided in the housing Il! and is arranged to be selectively connected to either the shaft 2| or the shaft 22 of the reels I9 and 20, respectively, for driving one reel or the other, as desired. in a clockwise direction, as viewed in Figure 3. This motor 3| is preferablv mounted in an vinclined position, as shown in Figure 2, with its drive shaft 32 extending substantially perpendicular to the panel portion I4. The motor 3| may be `conveniently mounted on a bracket 33 which is ,secured to the base II, as at 34. and to the motor as at 35. As shown in Figure 2, an opening 36 is provided in the base I I into which the casing of the motor extends. but does not completely pass therethrough. This opening 36 is provided as a. Ventilating opening.and facilitates circulation of air around the motor and the amplifying equipment presently to be described.
Drive pulleys 31 and 38 are mounted on the shafts 2| and 22, which carry the reels I9 and 20, respectively. It will be noted that the pulley 31 is smaller than the pulley 38 in order to increase the rewind speed.
As shown in Figures 2, 3, 5 and 6 of the drawings, the shafts 22 and 2I pass through the panel portion I5 and then through the skeleton frame structure 39 and 39', respectively; each of which includes a back plate 40 and a plurality of spacer plates 4|. These structures 39 and 39 are associated with each of the shafts 22 and 2| on the rear of the panel portion I5, and contain the mechanism for reciprocating the level winding guide ngers 30 and 29. While the structures 39 and 39' associated with the two shafts 22 and 2| are not identical. they are very similar, and for that reason a detailed description of only one of the structures, namely the structure 39 associated with the shaft 22, will be discussed. The structure 39, which is associated with the shaft 22 is shown in detail in Figures 5 and 6.
The shaft 22 is mounted in bushings 25| and 252 which are carried, respectively, by the panel portion I 5 and the back plate 49. Formed or attached on the center portion of the shaft 22 is a worm 253. Meshing with the worm 253 is a worm wheel 254 which is secured to a shaft 255 which extends generally downwardly and substantially at right angles to shaft 22. Shaft 255 has formed or secured thereon below the worm wheel 254,
a worm 256 which meshes with a worm wheel 251 mounted on a shaft 258 which extends substantially at right angles not only to the shaft 22 but also to the shaft 255. The shaft 258 is mounted on two of the spacer members 4I on opposite sides of the skeleton structure 39. Mounted on one end of the shaft 258 is a. heartshaped cam 259 which is arranged to engage a cam follower 260 which is in the form of an inverted L-shaped finger which is secured to a rod 26| which carries the level Winder guide iinger 30. The end of the cam follower 268 projects through a slot 262 in the spacer member 4| adjacent the cam 259.
Also connected to the shaft 25-8 is a exible drive cable 42 which drives the counter mechanism 43 which indicates the relative position of 4any portion of the record medium I8 with relevel Winder guide finger 29.' A biasing spring 265 in the form of a resilient Wire having several turns inthe center is secured at one end of the back plate 48 of' the skeleton frame `structure 39 associated 'with the shaft 2| as at 266, and is secured at its other end to the end of the link arm 45 as at 261. This spring 265 resiliently holds the cam follower 268 against the heartshaped cam 259.
Referring now to Figure 3, a pair of do'g leg levers 46 and 41 are pivotally mounted as at 48 and 49 to a bracket 50 which is secured to the rear end wall of the motor 3| by attaching bolts 5|. The dog leg levers 46 and 41 each have downwardly projecting legs 52 and 53 respectively, on which is pivotally mounted driving pulleys 54 and 55, respectively. Drive pulley 54 is associated and mechanically coupled to a friction roller 56, while drive pulley 55 is associated with and mechanically coupled to a friction roller 51. Fixed to the motor drive shaft 32 is a friction roller 58 against which friction roller 56 and friction roller 41 are selectively arranged to be moved into driving contact. A flexible drive cable 59 extends around drive pulleys 54 and 31. A flexible drive cable 60 extends around drive pulleys 55 and 38.
As shown in Figure 3, the friction roller 58 is in driven engagement with they drive roller 58, and, accordingly, the shaft 2| is being driven'by the motor 3|. 'Ihis in turn causes reel I9 to be driven in a counterclockwise direction as viewed in Figure 1, and accordingly the wire I8 is being unwound from the reel 28 and rewound on the' reel I9. When'the friction roller 56 is moved out of engagement with the friction roller 58 and the friction roller 51 is moved into engagement with the friction roller 58 the shaft 22 is driven by the motor 3| which in turn causes the reel 28 to be rotated in a counter-clockwise direction, as viewed in Figure 1.
The dog leg levers 46 and" have upwardlyv extending bent leg portions 6| and 62, as is clearly shown in Figures 2 and 3. A ringer 63 extends between the two upstanding legs 6I and 62 and is arranged to be moved by the motor control operating handle 64. Thearm A6.3 is pivotally mounted on a bracket 65, as at 6-5', which is supported on a frame construction 66 mounted on the rearv of the lower panel portion I4. As is diagrammatically shown in Figure 4, the motor control operating handle 64 is pivotally mounted on the subframe member -66 as at 61. The motor control 64 determines Whether the motor is causing the wire I8 to be moved in a recording and reproducing direction through the recordinghead I6, or whether the motor is causing the wire I8 to be rewoundon reel I9. When the handle 64 is thrown to the right as viewed in Figure 1 or downwardly as viewed in Figure 4, the wire I8 is moving in a recording and reproducing direction (i. e., it is being wound up on reel 28). When the handle 64 is thrown to the left as viewed in Figure 1 or upwardly (as shown) in Figure 4, the wire I8 is moving in a rewinding direction (i. e., it is being rewound on reel I9). When the handle 64 is in an intermediate or central position, the wireis stationary and the motor 3| is deenergized. Although not shown, it is to be understood that the handle 64 operates an electric switch which closes the energization circuit of the motor 3| when the handle 64 is moved in either direction.
When the finger 63 is rocked against the upper f leg portion 62 of the dog lever 41 the friction roller 51 is moved out of engagement with the friction drive roller 58 against the action of the tension spring 68 which extends between and is secured to the lower ends of the leg portions 52 and 53. Similarly, when the lever 64 is rotated so as to move the finger 63 against the upper leg portion 6|, the friction roller A56 is moved away from the friction roller 58 and at the same time the tension spring 68 pulls the friction roller 51 into engagement with the friction .roller 58. When the riger 63 is in its mid position friction rollers 56 and 51 fare beth pulled against friction roller 58 by the spring 68. Since these rollers 56 and 51 try to drive the wire I8 in opposite directions, it will at once be apparent that the friction drive rolls 56 and 51 of themselves act and serve as a brake for stopping the motor 3| as well as immediately stopping movement of the wire I8.
Also mounted within the housing I8 is the amplifying equipment, generally indicated at 69 in Figure 2. The amplifying equipment 69 is mount` ed to the rear of and around the motor` 3|. A loud speaker 18 is mounted on the lower panel portion I4.
Turning to Figure 1 of the drawings, the left portion of the lower panel I4 contains an opening 1|, which is covered by the cloth lscreen 12, which covers theI open front of the speaker 18.
On the right-hand side of the lower panel .por-
tion I4 are the control knobs and indicating means for the electrical circuits. Control knob 13 is a volume control; control knob 14 is an on-and-ofl switch, as well as the tone control; and control knob 15 determines whether the electrical circuit will operate as a recorder or as a reproducer. To the left of control knob 15 is a red light 16 which is lit when the control knob 15 is moved to a. Dosition for operating the apparatus as a recorder. A green light 11 is located to the right of the control knob 15 and is lit when the control knob 15 is moved to a position for causing the apparatus to operate as a. reproducing unit. A neon bulb 18 is located above the control knob 15 and, as will presently be explained, indicates the proper volume setting when the apparatus is operated as a recorder.
The motor control 64 is located on the front of the panel portion I4, as shown in Figure 1, While the indicating means 43 is located to the left thereof.
The electrical circuit of the apparatus is diagrammatcally shown in Figure 7. The electrical circuit in general includes the magnetic recording head and the audio amplier, a loud speaker and microphone plug which is `arranged to be connected to any suitable type of microphone. With the switch connections as shown in Figure 7, the apparatus is in a position for reproducing sound vibrations which have previously been recorded on the wire |8. The magnetic recording headV includes a coil 19 which is magnetically associated with the wire I8 or, in other words, it is so related to the wire I8 that the lines of flux produced by the magnetized wire will intersect the windings of the coil 19. In the preferred form of the invention the wire I8 passes ldirectly through the tapered pole portion 88 of a laminated iron core member 8| and through a portion of the coil 19 which surrounds the tapered pole portions 88 and the air gap therebetween. The coil 19 is connected to theinput grid electrode 82 of the first audio ampliiier tube 83 through a shielded conductor 84 (the shield being indicated by the broken lines 85). The other side of the coil 19 is connected to the cathode 86 of the electron discharge device 83 through the conductor 81. As is indicated at 88, the cathode 86 and the conductor 81 is grounded. Two switches 89 and 98 are connected in the circuit of conductor 84. Interposed between the switch 98 and the grid electrode 82 is a bias cell 9|. nected through a. high resistance 92 to the grounded Shield 85.
The electron dis'charge'device 83 may 'be of any suitable type for use in an audio amplier and as shown 'is of the multigrid type.- More particularly, the electron discharge device 83, in addition to the input grid electrode 82 andthe cathode 86, includes a heating filament 93, a screen grid electrode 94, a suppresser grid ,electrodel 95 and an anode 96. A second stage of amplification is provided by an electron discharge device 91 which is connectedby a capacity coupling 98 to the output circuit of the electron discharge de- The electron discharge device 91 is similar to' the electron dischargedevice 83 andincludes, in addition to the grid electrode |08, a heating filament |8I, a cathode |82, a screen grid electrode |83, a suppresser grid electrode |85 'and an anode,
|86. The cathode |82 is providedv with avselfbiasing resistor |81 and a by-pass condenser |88Y to maintain the lcathode at the desired'- potential. Y
This cell 9| is con-` 7 The screen grid |03 and the suppresser grid |05 are connected to the circuit in the conventional manner, the screen grid |03 being given a suitable positive bias through a circuit presently to be explained, and connected to ground through the by-pass condenser |09. Y
The anode-cathode circuit of the electron discharge device 91 is provided with aby-pass condenser lI and a variable tone control resistor III which are connected between the anode |08 and ground. The anode |06 is also connected through a couplingl condenser H2 to the input grid electrode H3, of an output or power tube ||4. A self-biasing resistor I|5 is connected between the grid electrode ||3and ground,
The output of power tube ||4, in addition to the grid II3, includes a filament II6, a cathode ||1, a screen grid ||8, a suppresser grid I|9 and an anode |20. The suppresser grid I I9 is directly connected to the cathode ||1 in the conventional manner, while the screen grid ||8 receives a suitable biasing potential, in a manner presently to be explained. The cathode ||1 is connected through a self-biasing resistor |2| and a parallel connected filter condenser |22 to ground.
In the output circuit of the power amplier tube I|4 is the neon lamp circuit. This neon lamp circuit includes a condenser |23 and a variable resistance element |24, which are connected in series between the anode |20 and the grounded conductor 81. The neon lamp 18 is connected between the grounded conductor 81 and the movable element |25 of the resistor |24 which determines the voltage drop across the neon lamp.
The power amplifier tube ||4 is connected to an output transformer |26. The input winding or primary of the transformer |26 is connected between the anode |20 of the power amplifier tube I|4 and the screen grid I|8 of the same tube. The secondary of the transformer |26 has its opposite end connected to an output jack |21 and a resistance element |28. An intermediate point |29 on the secondary of the transformer |26 is connected to the grounded conductor 81 and also to a contact point |30 of a switch 3|. A second intermediate point |32 is connected to a second contact point |33 of the switch |3I.
A loud speaker |34 is connected through switch |3I on one side to the tapped point |32 on the secondary of the transformer |26, while it is connected through the separable contact elements |35 and |36 of the output jack |21 to the tapped point I 29 on the secondary of the transformer |26. With the switch I3| in the position shown in Figure 7 of the drawing, the speaker |34 is arranged to be energized from the output of the ampliiier. 'Conductors |31 and |38 are connected to a shorting switch (not shown), which is arranged to be closed when the unit is being rewound.
Power for the amplier circuit is obtained through a rectitler unit |39 which includes a power transformer |40, a rectier tube |4I, and suitable filter elements presently to be described. The input side of the power transformer |40 is connected through a plug |42 to a suitable source of alternating current (not shown), such for example as the conventional 110 volt 60 cycle alternating current available in most cities. An overload fuse |43 is connected between plug |42 and transformer |40, in one part of the circuit, and an on-oft switch |44 is connected in the circuit on' the opposite side. The switch |44 is preferably combined with the tone control and operated from a single knob 14 (Figure 1).
In addition to a primary winding |45 on the power transformer |40, there are provided three secondary windings |46, |41 and |48. The secondary winding |45 is arranged to be connected to the filaments 93, |0| and ||6 of the tubes 83, 91 and II4. The arrows associated with winding |48 indicate diagrammatically that they are arranged to be connected to the arrows on the iilament elements referred to.
The secondary winding |46 supplies power to the cathode |49 of the rectifier tube |4I. Two anodes |50 and |5I are connected to opposite ends of the winding |41. The center point on windings |41 and |48 are both grounded through a conductor |52. A group of lter condensers |53 and |56 are connected in the circuit as shown, while an inductive reactance element |51 is connected in the circuit of the coil |46 and the cathode |49. Resistance elements |58 and |59 are also provided and are connected vin a conventional manner. It is to be understood that the circuit arrangement above described is a conventional full wave rectifler circuit for supplying the desired potential to the various elements of the audio amplifier. The desired positive potential for anode 96 and screen grid 94 of tube 83 is obtained through conductor |60 and dropping resistors |6| and |62. The desired potential for anode |06 and screen gridv |03 of tube 91 is obtained through conductor |63 and dropping resistors |64 and |65. The desired potential for anode |20 and screen grid ||8 of tube I|4 is obtained through conductor |66, the conductor |66 being connected through the primary winding of the output transformer |26 to the anode |20 while being directly connected to the screen grid I|8.
The red pilot light 16 and the green pilot light 11 are energized directly from the secondary winding |48 of the power transformer, a switch |61 being arranged to selectively energize either the green pilot light 11 or the red` pilot light 1,6. As is indicated in Figure 7, the green pilot'l light is in a state of energization and, as has previously been mentioned, this indicates that the circuit is arranged to reproduce sound vibrations magnetically recorded onthe recording medium I8. When the apparatus hereinbefore described is to be employed for recording sound vibrations on the record medium I8 a high frequency oscillator is necessary. Suchan oscillator is diagrammatically illustrated in Figure '1 and includes an electron discharge device or oscillator tube |68 which is provided with a filament |69,y a cathode |10, a control grid I1I, a screen grid |12, a suppresser grid |13 and an anode |14. A tuned circuit including an inductance |15 and ,a parallel connected con'- denser |16 is provided. The inductance |15 and the condenser |16 are connected at one end to the anode |14 and are connected at their other end through a condenser 11 to the input grid |1| of the oscillator tube |68. The lower end of the tuned circuit is also connected through a conductor |18, a condenser |19 to a conductor |80, which is connected to the magnetic head I6 in a manner presently to be explained. A bias resistor |8| is provided between the control grid |1| of tube 68 and cathode |10. The cathode |10 is connected through a condenser |82 to an intermediate point I 83 on inductance |15. This intermediate point |83 is arranged to be connected through a switch |84 to the high potential side of a source of electric energy, as
.l N0. 2,351,004, issued June 13, 1944.
9 supplied through conductor |66. Cathode is also connected through a conductor |85 to the grounded side of an equalizer circuit |86.
The equalizer circuit |86 is a lter circuit including a plurality of inductance elements |81, a plurality of resistance elements |88 and a. plurality of condensers |89, which are preferably connected together in the manner shown in the drawings. One end of the equalizer circuit |86 is arranged to be connected through a switch |90i to either the grounded conductor 81 or to a conductor |9|. The conductor |9| is connected to a condenser |92 and a conductor |93 to the output circuit of the tube ||4 in the manner shown.
It is to be understood that the oscillator |68 and its associated circuits are employed only when the equipment is being employed as a recorder. When the equipment is being employed as a reproducer, as hereinbefore described, the oscillator is cut out of the circuit in a manner which will be readily apparent from an inspection of the drawings. Switches 89, 90, |3|, |61, |84 and |90, as well as a switch |94, which connects the output conductor |80 of the oscillator circuit to the recording head I6, are all arranged to be moved from their full line position as shown in Figure 7, to their dotted line position as shown in Figure 7 when it is desired to operate the equipment as a recorder rather than as a reproducer. To this end, all of these switches 89, 90, |3I, |61, |84, |90 and |94 are all preferably mounted as a gang switch for operation by the control switch (Figure 1), which control switch or lever, as previously described, also controls the direction of rotation of the reels I9 and 20.
A description of the equipment and its operation as a recorder will now be made. Assume that all ofthe switches 89, 90, |3I, |61, |84, |90 and |94 are thrown to their dotted line positions and that the record medium or wire |8 is moving from right to left, as viewed in Figure '7. The high frequency alternating current flow in the tuned circuit of the oscillator, and particularly in the inductance |15, causes a high frequency current to be induced in the Winding |95 which is connected to the erasing coil I1.
Since the wire or recording medium I8 is passing through the erasing head I1 prior to the time when it reaches the recording head I6, all
previous magnetization of the wire or magnetization resulting from any extraneous source is removed from the wire I8 immediately prior to the time it enters the recording head I6.
A microphone is connected through a suitable lead (not shown) to the microphone plug |96 which forces the movable center contact |91 away from its engagement with its stationary seat |99 and thus causes the voice energy to be transmitted through switch 90 by a cell 9| to the control grid 82 of the rst tube 83 of the amplifier circuit. The output of the audio amplifier is connected to the equalizer |86. the conductor |80 and the switch |94 .to the coil 19 of the recording head`|6. The output of the oscillator tube |66 is also fed through a coupling condenser I 19 to the same input conductor |80 of the recording head I6. This causes a superimposing (as distinct from amodulaton) of the audio frequency current on the high frequency current generated in the oscillator tube |68.
vided. One contact 200 of the jack |99 is con nected directly to the input circuit of the second stage of audio amplification as represented by the tube 91. More particularly, the contact 200 is connected to the upper end of the potentiometer 99, which in turn is connected through a movable contact 20|` to the control grid |00 of the tube 91. The other contact 202 of the jack |99 is connected to the grounded conductor 81 through a conductor 203. This arrangement may be conveniently used to record incoming radio programs or the like directly on the record medium I6. Since the amplification from the output of a radio, or other similar equipment, is usually considerably greater in intensity than the output which may be obtained from any microphone circuit, the rst stage of amplification in the audio amplier is skipped, when it is desired to record an incoming radio program, or the like, by connecting the outputof the radio (not shown) to the jack |99.
The jack |21, which has previously been described, is provided in the equipment for the purpose of using a separate and larger loud speaker (not shown), if desired, when the equipment is being operated as a reproducer.
It will be observed that when the equipment isset for reproduction, the switch |61 connects the green light 11 to the energizing winding |48 of the transformer |40. When the switch |61 is in its dotted line position, as it is placed when the equipment is being operated as a recorder, the red light 16 is connected to the energizing winding |48 of the transformer |40 `instead of the lamp 11. Y
Associated with the switch arm 64 and the counter mechanism 43 is means for automatically moving the switch 64 to its neutral position. More particularly, the shaft 204 extends out of the counter mechanism 43 and carries on the end thereof a cam cylinder 205 which has a transverse groove 206 therein immediately followed by a transverse raised portion 201. An arm 208 is pivotally mounted for movement about the point 209 and is spring biased by a coil spring 2|0 for movement in a clockwise direction, as viewed in Figure 4. The right-hand end of the member 208 is provided with a cam engaging portion or protuberance 2|| which rides in` engagement with the cam cylinder 205. A link member 2 l2 extends to the inner end yof the switch arm 64 where the inner end of the switch arm 64 engages the forked end 2|3 of the arm 63. The Yconnecting arm 2|2 is pivotally mounted to the inner end of the switch arm 64 as at 2|4. The opposite end of the connecting arm 2|2 is bent as at 2|5 to provide an abutment surface and again at 2 6 to pro- Vide a second abutment surface which is arranged to be engaged by the end 2|1 of the arm 208, as will presently be described.
The above described mechanism, as will read@ ily be appreciated by those skilled in the art, is an extremely compact and rugged equipment for recording and reproduction of sound vibrations. It has been found in practice that a relatively small spool or wire, such as may conveniently be mounted on a small portable unit, will carry sufiicient wire to record or reproduce continuously for several hours. Much longer periods of recording and reproducing may be obtained by using larger spools and longer lengths of wire.
While I have shown a particular embodiment 4 of my invention, it will, of course, be understood that I do not wish to be limited thereto, since many modifications may be made and I, therefore, contemplate by the appended claims to cover all such modifications as fall within the true spirit and scope of my invention.
I claim as my invention:
1. In a magnetic recording and reproducing unit, a support including a casing having a panel and a base, a recording and reproducing electromagnetic head mounted on said panel, a long paramagnetic wire or tape, a pair of reels rotatably mounted on said panel for rotation about axes extending substantially perpendicular to said panel and oniwhich the ends of said wire l2 or tape are disposed and around which the bulk of said wire or tape is wound, said head being disposed to have said wire or tape pass therethrough, a motor mounted on said support and having a friction driving drum, a pair of levers rockably mounted in proximity to said motor and each having a friction drum to be driven rotatably mounted thereon, said driven drums being disposed on opposite sides of said driving drum,Y 10 spring means urging said driven drums into frictional engagement with lsaid driving drum, control means for selectively moving one or the otherY of said members to move its associated driven drum out of engagement with said driving drlmi,
whereby either of said driven drums may be selectively retained in driving engagement with said driving member, and means coupling said driven drums to said reels respectively for rotatably driving said reels.
2. In a magnetic recording unit a supporting structure, a recording electromagnetic head mounted on said structure, a long paramagnetic wire or tape, a pair of reels rotatably mounted on said structure and on which the ends of said wire or tape are disposed and around which the bulk of said wire or tape is wound, said recording head being disposed in magnetizing relation to said wire or tape, driving means mounted on said structure and having a friction drive drum,
a pair of members rockably mounted in proximity to said motor and each having a friction drum rotatably mounted thereon and arranged to be driven by said driving drum, said driven drums being disposed on opposite sides of said driving drum, means above both of said driven drums of said driven drums may be selectively retained in driving engagement with said driving member, and means for transmitting rotational movement of said driven drums to said reels respectively. 5 MARVIN CAMRAS.
file of this patent:
UNITED STATES PATENTS Number Name Date 2,089,287 Molloy Aug. 10, 1937 2,281,793 Patrick May 5, 1942 2,078,357 Woodmansee Apr. 27, 1937 1,142,384 Tiiany June 8, 1915 1,883,560 Chipman Oct. 18, 1932 2,086,130 Hickman July 6, 1937 2,277,305 Clopton Mar. 24, 1942
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US511253A US2418541A (en) | 1943-11-22 | 1943-11-22 | Reversible drive for a magnetic recording medium |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US511253A US2418541A (en) | 1943-11-22 | 1943-11-22 | Reversible drive for a magnetic recording medium |
Publications (1)
Publication Number | Publication Date |
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US2418541A true US2418541A (en) | 1947-04-08 |
Family
ID=24034101
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US511253A Expired - Lifetime US2418541A (en) | 1943-11-22 | 1943-11-22 | Reversible drive for a magnetic recording medium |
Country Status (1)
Country | Link |
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US (1) | US2418541A (en) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2563545A (en) * | 1951-08-07 | Sound recording and reproducing | ||
US2604548A (en) * | 1946-12-05 | 1952-07-22 | Brush Dev Co | Apparatus for demagnetizing magnetic recording-reproducting heads |
US2641655A (en) * | 1947-11-24 | 1953-06-09 | Int Electronics Co | Magnetic recording and reproducing circuits |
US2645682A (en) * | 1947-09-12 | 1953-07-14 | Brush Dev Co | Magnetic recording and reproducing |
US2658952A (en) * | 1949-05-10 | 1953-11-10 | Clevite Corp | Magnetic recording and reproducing device |
US2694108A (en) * | 1949-08-30 | 1954-11-09 | Dietaphone Corp | Magnetic recording and reproducing system |
US2712369A (en) * | 1948-09-08 | 1955-07-05 | Ralph J Samuels | Magnetic recorder |
US2786896A (en) * | 1953-03-04 | 1957-03-26 | Int Electronics Co | Magnetic recording and reproducing circuits |
US2935879A (en) * | 1954-08-16 | 1960-05-10 | Vm Corp | Driving mechanism for magnetic recorder and player |
US4271714A (en) * | 1979-05-16 | 1981-06-09 | Matsushita Electric Corporation Of America | Drive mechanism |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1142384A (en) * | 1909-03-17 | 1915-06-08 | American Telegraphone Company | Telegraphone. |
US1883560A (en) * | 1929-10-10 | 1932-10-18 | Andrew Le Roy Chipman | Electromagnetic sound recording and reproducing machine |
US2078357A (en) * | 1933-11-25 | 1937-04-27 | American Talking Wire Company | Telegraphone apparatus and circuit |
US2086130A (en) * | 1936-10-07 | 1937-07-06 | Bell Telephone Labor Inc | Telegraphone |
US2089287A (en) * | 1936-11-23 | 1937-08-10 | Tom J Molloy | Recording and reproducing mechanism |
US2277305A (en) * | 1941-04-18 | 1942-03-24 | Clopton Alexander Browning | Recording and reproducing device |
US2281793A (en) * | 1938-12-27 | 1942-05-05 | William P Patrick | Magnetic recorder |
-
1943
- 1943-11-22 US US511253A patent/US2418541A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1142384A (en) * | 1909-03-17 | 1915-06-08 | American Telegraphone Company | Telegraphone. |
US1883560A (en) * | 1929-10-10 | 1932-10-18 | Andrew Le Roy Chipman | Electromagnetic sound recording and reproducing machine |
US2078357A (en) * | 1933-11-25 | 1937-04-27 | American Talking Wire Company | Telegraphone apparatus and circuit |
US2086130A (en) * | 1936-10-07 | 1937-07-06 | Bell Telephone Labor Inc | Telegraphone |
US2089287A (en) * | 1936-11-23 | 1937-08-10 | Tom J Molloy | Recording and reproducing mechanism |
US2281793A (en) * | 1938-12-27 | 1942-05-05 | William P Patrick | Magnetic recorder |
US2277305A (en) * | 1941-04-18 | 1942-03-24 | Clopton Alexander Browning | Recording and reproducing device |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2563545A (en) * | 1951-08-07 | Sound recording and reproducing | ||
US2604548A (en) * | 1946-12-05 | 1952-07-22 | Brush Dev Co | Apparatus for demagnetizing magnetic recording-reproducting heads |
US2645682A (en) * | 1947-09-12 | 1953-07-14 | Brush Dev Co | Magnetic recording and reproducing |
US2641655A (en) * | 1947-11-24 | 1953-06-09 | Int Electronics Co | Magnetic recording and reproducing circuits |
US2712369A (en) * | 1948-09-08 | 1955-07-05 | Ralph J Samuels | Magnetic recorder |
US2658952A (en) * | 1949-05-10 | 1953-11-10 | Clevite Corp | Magnetic recording and reproducing device |
US2694108A (en) * | 1949-08-30 | 1954-11-09 | Dietaphone Corp | Magnetic recording and reproducing system |
US2786896A (en) * | 1953-03-04 | 1957-03-26 | Int Electronics Co | Magnetic recording and reproducing circuits |
US2935879A (en) * | 1954-08-16 | 1960-05-10 | Vm Corp | Driving mechanism for magnetic recorder and player |
US4271714A (en) * | 1979-05-16 | 1981-06-09 | Matsushita Electric Corporation Of America | Drive mechanism |
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