US2480742A - Magazine type magnetic recording apparatus - Google Patents

Description

Aug. 30, 1949. E. L. KENT MAGAZINE TYPE MAGNETIC RECORDING APPARATUS 2 Sheets-Sheet 1 I Filed May so, 1945 Aug. 30, 1949* E. KENT 2,480,742

MAGAZINE TYPE MAGNETIC RECORDING APPARATUS Filed May 30, 1945 2 Sheets-Sheet 2 Patented Aug. 30, 1949 UNITED STAT MAGAZINE TYPE MAGNETIC RECORDING APPARATUS Earle L. Kent, Elkhart, Ind., assignor to C. G.

Conn, Ltd., Elkhart, diana Ind., a corporation of In- Application May 30, 1945, Serial No. 596,705

6 Claims. 1

This invention relates to magnetic recording apparatus and more particularly to apparatus for magnetically recording a signal on wire or reproducing the signal from the wire.

Magnetic recording apparatus, as heretofore constructed, comprises in general a pair of reels or spools between which the wire travels and a magnetic head engaging the wire between the reels or spools for magnetically impressing a signal thereon or for reproducing a signal previously impressed on the wire. In apparatus where high fidelity is desired the wire is usually driven by a capstan separate from the reels to maintain a uniform velocity of the wire through the head.

It is one of the objects of the present invention to provide a magnetic recording apparatus in which accurate wire speed can be maintained without the use of a separate capstan. According to the invention, this is accomplished by providing a take-up reel or spool of substantially larger diameter than the supply reel or spool so that the effective diameter change of the takeup spool as the wire is wound thereon or unwound therefrom is relatively small and a substantially constant velocity of the wire can be produced by driving the take-up spool at a constant rotary speed.

Another disadvantage of prior constructions is that it has heretofore been necessary to rewind the wire from the take-up spool to the supply spool on the machine. This procedure ties up the recording or reproducing machine for substantial periods of time during rewinding so that the recording or reproducing operation is undesirably interrupted.

It is another object of the present invention to provide a magnetic recording apparatus in which rewinding can be accomplished on an entirely different machine so that the recording or reproducing operation can be substantially continuous. For this purpose, the invention contemplates the provision of a plate or support carrying the supply and take-up reels and which can be detachably connected to the recording or reproducin apparatus to mount the reels thereon.

According to another feature of the invention, the supply reel is detachable from the plate so that only one or two plates need be provided for each machine and as many supply reels as desired can be made immediately available.

According to still another feature, the position of the wire carried by the reels relativeto the head is accurately indicated by a revolution indicator or counter connected to the take-up reel.

With this construction, any desired part of a recording can be selected for reproduction without the necessity of running the entire recording.

According to a still further feature, the plate is so constructed as to move the wire out of engagement with the head during the operation of removing the plate from the apparatus thereby simplifying the handling of the plate and insurin that the wire will not be damaged.

It has been found in previous recording and reproducing devices that aclosed type of head in which the coils completely encircle the wire produces much higher fidelity in recording and reproduction than an open type head in which the coils do not continue around the wire. Such closed type heads, however, require that the wire be threaded from one end which is frequently a slow and tedious operation and which would prevent removal of a plate carrying the reels except when the wire is completely wound on one or the other of the reels.

The present invention has for another of its objects the provision of a head which can be opened for insertion or removal of the wire in the manner of an open type head and which can be closed to function as a closed type head. In one desirable construction, the head includes a switch blade which is openable to permit insertion and removal of the wire and which can be closed to complete a circuit substantially encircling the wire.

It is still another object to provide a magnetic recording apparatus in which a common switch blade controls a plurality of circuits such as recording or reproducing circuits and erasing circuits.

It is still another object to provide a head construction in which opening of the head posi tively removes the wire therefrom.

The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which Figure 1 is a perspective view of one form of apparatus embodying the invention with the plate and reels removed;

Figure -2 is a view similar to Figure 1 with the plate attached;

Figure 3 is an enlarged front elevation of the head of Figures 1 and 2;

Figure 4 is a side elevation of the head;

Figure 5 is a disassembled view of the head;

7 Figure 6 is an enlarged partial section through t e head plate on the line 6-6 of Figure 5; and- Figure 7 is a partial perspective view of an alternative construction The apparatus, as shown in Figures 1 and 2, comprises a casing l which is adapted to contain a driving motor and recording or reproducing circuits for magnetically recording a signal on a wirexorreproducingthe signalirom the wire. The motor andrecording or reproducingtcircuits may be controlled by switches H and operation of the amplifier and recording circuit may be indicated by pilot lights I2 onthe casing front wall. The recording or reproducingievermay be indicated by a meter I3. The controls andthe particular recording or reproducing circuits per.

se form no part of the present imrentiorriand are, therefore, not illustrated or described in detail herein.

The front side of the casing h'as projecting therethrough a pair of drive clutch members l l' and which may be driven in any desired manner: by the motor; inthe casingsand which are adapted to engage takeeupand supply reels'or spools to drive them. Adjacent. the clutch memhers-the casing carriesr'a magnetic head indicated generally at I fi'andswhich is: energized or which energizes: the recordingor reproducing circuits to cause. arecordingiorreproducing operation as the wire travels-through@thehead.

According to :therpresent invention, the supply and "take-up reels .or'spools which carry; the. wire are carried by a plates" whichzisiadapted to be detachably mountedmrr'th'ewasing front wall. As shown, the casing;- front -wall carries clamping brackets I 8 which are adapted: to. engage: clamp.- ing projections on the:platez|1." Asshown, clamping screws I 9 are carried ibyrthe plate and are adapted to cooperaterwitlr theaclampingcbrackets to secure the plate tocthe casing when desired.

The. plate carries? a take up reel .or spool "2| which may be permanenthtattached. thereto and which includes an outer casing supporting'a spool on its interior. The-r spool. is so formed as to engage the clutchsmemher M-i through anopening or cut out portiorrhnthe plate so that the spoolnmay: be driven-shy theeclutch :member; As shown, the-take+uprspool casingriszformedwith an opening; 22 *throu'ghrwhiclrtheswirezmay pass and which mayibeclosed' bya-rotatableagate meme ber 23 which; rotatablyisupportedg on the: :ex terior 'of'the' casingibodyr.

A supply reel or spool indicated generally=at 24 isdetachably connected to theiplateby means of releasable :clamping members'rfi so that the supply reer earthenconnectedto omdisconnected from the :plate; .asidesired; Thersupply reel may take the form of any of the reels more particu-a larly disclosedtandhlaimed irr thecco-pending applications -of- LelandzBsGreenleaf; Serial Nos: 566 105, filed Decemb'erfl;1944;566a106; filedi'Decemberr1, 1944; 589:,043,"fil'd April: 18;:1945; now 'matured iinto Patent New 2,401,632; issued" June 4, 1946;. As". shown; iticompri's'esranuouter casing formedwitl'r anfopening -.throughr which the wire may pass and which may be closed by arotatable gatesmernber:operatecttbyiamoperating finger. 26. Thesupplyreeleregisters. with an opening or cut out portion in the: platecl'i through which the spootimay engage the'driving member 15 to be driven by the motor in theicasingforrewinding orto h'avesazpre determined drag applied thereto to maintain tension on the'fwire when. wire is being", wound on'..thetakei-up: spool With this construction :any number of supply spools can 'beprovidedwand stored-, each containinga-recorded 'signalior: programwor being-blank for having signals recorded thereon. Two or more plates, each having a take-up spool may be provided for each recording or reproducing apparatus so that while one plate is on the machine, the other may be attached to a rewinding machine for rewinding the wire from the take-up spool to the supply 510001.. Thesupply spools may easily be exchanged on the. plate which is detached from the apparatus so that a recorded program may be played or recorded continuously with only the short interruptions required to exchange the plates.

In order that any pre-determined part of a recording or any, pre-determined portion of the wire ontwhich a recording is to be made can be selected, a. rotation indicator or counter 27 is connected tothe take-up reel and is driven directly by the spool in the take-up reel. The counter canzbe set, for example, at zero when no wire is on the take-up spool and will accurately record the number of revolutions of the take-up spool during a recording or reproducing operation. To select any desired portion of the wire for recording signals thereon. or reproducing signals therefrom, the take-up spoolmay be turned on the recording-or reproducing apparatus or on a separate-winding machine until the counter 21 indicates' the rotary position of the take-up spool corresponding to the desired portion of the wire; It-has been. found that with this construction, any desired. part of the wirecan be selected accurately;

According to one-of the important features of theuinvention, thewiremay be withdrawn fromthe supply spool and wound on the take-up spool at substantially-constant linear-speed without the necessity of a separate capstan drive. purpose, the take-up spool is formed of relativelylarge diameter ascompared to the diameter of the supply spool. Therefore, as the wire is wound on the take-up, spool it undergoes a relatively small change in its effective diameter so that by driving it at'constant speed the wire will be drawn through thehead at a substantially constant linear speed. By way of example, the supply spool may. be-made with a hub or body portion one inch in 'diametercand may have wire wound thereon to a radial depth of one-half inch; The take-up spool may have its hub or body por tion approximately four inches in diameter so that when the complete supply of wire is wound thereon, the Wire will have a radial depth of only about one-eighth inch. This constitutes a maximum efiective change in diameter of the take-up spool ofonly about 6% so that the linear speed of the wire through the head will not vary more than a'maximum of 6%. For most purposes this issufiicient to provide the'desired fidelity so that a separate capstan drive'can be dispensed with.

The head 16 according to the present invention maybe constructed to provide a closed type head in which the wire can easily be inserted and removed. As shown the head comprises an insulating block 28 adapted to be supported by the casing in front of the front wall thereof. The block 28 carries a pair of guide members 29 formed of insulating material which are shaped at their lower edges to provide a guiding groove. Between the guide blocks 29, a magnetic plate BI is supported which is formed in its lower curved edge with a groove 32, as shown in Figure 6, within which the wire may lie to be guided in engagement with the plate. At'spaced points in its lower'edge the plate 3| is formed with slots 33 opening at their upper endsv intoopenings '34. Two

For this slots, as shown, may be employed when the head is utilized both to erase and record, it being understood that only one such slotwould be provided where the head is used for recording or for reproduction only.

The head parts, as abovedescribed, are assembled by means of bolts 35 passing through the several parts and holding them'together. Contact rods or pins 36 are then passed through the guide and insulating blocks and through the openings 34 in the plate 3|. The contact rods 36 project beyond the rearward end of the block 28 and carry contacts 31 to which wires from the recording or reproducing circuit may be connected. The block 28 also carries at its lower edge fixed contacts 38 to which the other sides of the recording and reproducing circuits are connected. In order to close the recording and reproducing circuits around a wire engaging the edge of the plate 3!, a switch blade 39 is pivoted to the outer ends of the contact bars 36 with its outer end forked to engage the contacts 38 respectively. As shown, a single bar 39 is provided which forms a part of both the erasing and recording circuits although, if preferred, separate bars insulated from each other could be used. I have found that with a single bar, as shown, the apparatus functions satisfactory to erase a previous signal from the wire and to record a new signal thereon.

With this construction, when it is desired to connect a plate to the apparatus or to remove a plate therefrom the switch blade may be raised to the position shown in Figure 1 at which time the wire may easily be laid in the guide groove or removed therefrom. With the wire in place, the switch blade is moved down to the operating position shown in Figure 2 in which position it complei-es a circuit from the contacts 3'! through the contract bars 36 and switch blade 39 to the contacts 38 substantially encircling the wire. In the head, as shown, a single turn around the wire is provided in both the recording and erasing circuits although by obvious changes, it will be apparent that multiple turn heads could be provided.

To assist in removal of the wire from the groove when the switch is opened, means are provided connected to the switch blade 39 to engage the wire and move it out of the guide groove. This means, as shown, includes an elongated pivot rod 4! on which the switch blade is mounted and which extends across the width of the head. Fingers 42 are connected to the rod 4| adjacent the sides of the head and are so formed that when they are swung down to the dotted position shown in Figure 4, by opening of the switch blade they will engage the wire and move it completely out of the head. With this construction to remove a plate from the apparatus, it is necessary only to open the switch blade to loosen the clamps and to lift the plate off of the casing since the fingers 42 will have moved the wire out of the head so that the wire cannot be damaged by catching in the head.

In the event the apparatus is to be used with an open type head, it may be constructed, as illustrated in Figure 7, in which the plate is shown at I? and the head is indicated generally at 43. This head may be similar in external appearance to the head of Figures 1 to 6 except that the switch blade is omitted and corresponding changes are made in the internal circuit in the head to magnetize the magnetic plate 4. The wire passing through the head to engage the plate 44 is illustrated at 45 and normally lies against 6 the slotted edge of the plate 44 so that recording or reproducing or erasing operations can be performed thereon, as desired.

In order to move the wire out of the head when the plate is to be removed from the apparatus, cam members 45 may be carried by the plate to lie adjacent the opposite sides of the head 43. The cam members 45, as shown, have sloping lower surfaces 51 which normally lie above and out of contact with the wire when the plate is in place on the apparatus. When the plate is removed, the sloping cam surfaces Q] will en gage the wire to cam it out of the groove in the head so that the plate can be removed by a simple operation without any possibility of breaking the wire.

While the invention has been described in connection with a particular form of apparatus, it

will be apparent that numerous changes might be made in the apparatus and that the particular form illustrated is not intended to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. Magnetic recording apparatus comprising a casing, spool driving means carried by the easing at one side thereof, a plate detachably secured to said one side of the casing having cut out portions therein to register with the driving means, spools carried by the plate to carry a wire and engaging the spool driving means, a magnetic head on the casing to project through a cut out portion in the plate, the head having a grooved part to receive the wire, and a movable switch part on the head adapted when closed to enclose a wire in the grooved part and when opened to permit insertion or removal of a Wire in the grooved part.

2. Magnetic recording apparatus comprising a casing, spool driving means carried by the casing at one side thereof, a plate detachably secured to said one side of the casing having cut out portions therein to register with the driving means, spools carried by the plate to carry a wire and engaging the spool driving means, a magnetic head on the casing to project through a cut out portion in the plate, the head having a grooved part to receive the wire, a movable switch part on the head adapted when closed to enclose a Wire in the grooved part and when opened to permit insertion or removal of a wire in the grooved part, and means on the switch part to engage the wire and remove it from the groove when the switch part is opened.

3. In a magnetic recording apparatus, a magnetic head comprising a magnetic plate formed at one edge to engage a wire, a conductor extending through the plate, a movable switch blade connected to the conductor, and a fixed contact spaced from said edge of the plate to be engaged by the switch blade in one position thereof to form a circuit substantially encircling a wire engaging said edge of the plate.

4. In a magnetic recording apparatus, a magnetic head comprising a magnetic plate formed at one edge to engage a wire, a conductor extending through the plate, a movable switch blade connected to the conductor, a fixed contact spaced from said edge of the plate to be engaged by the switch blade in one position thereof to form a circuit substantially encircling a Wire engaging said edge of the plate, and means moved by the switch blade when it is moved away from the contact to engage the wire and move it away from the plate.

ZASQJQ 543 In ame netic recording apparatus,; a, ma netie headcemn isinaa magnetic plate m d adjacent one edge with a; slot and having an opening adjacent the-slot, means to guide a wire ineneaeement. w th aid one edge of the plat a conductor extending through the opening, a

Switchblade pivotally connected to the conductor and a; fixed contact to be engaged by the switch blade in one position thereof to form a circ its lbstantially encircling the wire.

6., In. a magnetic recording apparatus, a head comprising a magnetic plate formed adjacent one edge with a plurality of spaced slots and having openings therethrough adjacent the slots, meanstc guide. a wire in engagement with said edge of the plate, a plurality of conductors extending; through the openings respectively, a fixed contact for each of the conductors spaced from-the conductors, and a movable switch blade connectedto the conductors and engageable with 2 the contacts to complete a plurality of circuits substantially encircling the wire.

. EARLE L. KENT.

The following referencesare of record in them of this; patent;

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