US2468198A - Magazine type magnetic recorder with multiple lane tape and traversing transducer - Google Patents

Description

April 26, 1949. H. s. HELLER 2,468,193

MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 5, 1945 I 9 Sheets-Sheet l IN V EN TOR.

HEB/VANS 622456 Aprll 26, 1949.. H. s. HELLER MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 3, 1945 9 Sheets-Sheet 2 INVENTOR. Hip/WW5 b22452, BY

N mm mm /l l mm A.

HELLER 2,468,198 MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 5, 1945 April 26, 1949.

9 Sheets-Sheet 3 INVENTOR. HE/QMA/ViAQZLE/P, BY I 221414/ 1. I I

,47'7'OE/VEX Aprll 26, 1949. HELLER 2,468,198

MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 3, 1945 9 Sheets-Sheet 4 INVENTOR. Him/4N5 his-445E,

p 1949- H. s. HELLER 6 ,198

MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 3, 1945 9 Sheets-Sheet 5 INVENTOR. Haw/4N5 1 /544542 Aprl] 26, 1949. HELLER 2,468,198

MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 3, 1945 9 Sheet's-Sheet 6 INVENTOR. AQ'AMA/Vj Haw/a, BY

April 1949- H. s. HELLER 2,468,198

MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed Aug. 5, 1945 v 9 Sheets-Sheet 7 ail INVEN TOR.

477'OP/VEX April 26, s HELLER 1 MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER Filed-Aug. 3, 1945 9 Sheets-Sheet 8 INVENTOR.

AZQMANJAZZAEA, BY

April 26, 1949- H. s. HELLER MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAVERSING TRANSDUCER 9 Sheets-Sheet 9 Filed Aug. 3, 1945 uvi zzvrozg .5 145445;,

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Patented Apr. 26, 1949 MAGAZINE TYPE MAGNETIC RECORDER WITH MULTIPLE LANE TAPE AND TRAV- ERSING TRANSDUCER Herman S. Heller, West Los Angeles, Calif. Application August 3, 1945, Serial No. 608,734

24 Claims.

This invention relates generally to sound recording and reproducing machines of the type employing a long record tape. In most of its aspects the invention is particularly applicable to sound recording and reproducing machines of the magnetic tape type, and will hereinafter be described primarily in that connection, though without necessary limitation thereto since certain features of the invention may have application to equipment utilizing record tapes of other than magnetic character.

The invention is directed particularly to recording and reproducing machines of the type utilizing a multiplicity of recording lanes spaced transversely across the tape. These lanes are normally used consecutively, with the tape traveling first in one direction and then in the other between a pair of tape reels. One advantage inherent in multiple lane recording resides in the fact that the tape may be much shorter for a given duration of recording time. For instance, assuming eight lanes across the tape, the tape need only be one-eighth as long as the tape or wire necessary for an equivalent recording time in single lane recording. An accompanying advantage is that the time duration for running the tape from end to end is reduced by the same factor, for example, by a. factor of eight, so that" the rewinding time is much reduced. Reference may be had to Patent No. 2,213,631, issued September 3, 1940, to Herman S. Heller and Leo G. Butler for disclosure of multiple lane recording of one type, wherein a set of recording and erasing magnets is provided for each lane of the tape. Reference is also had to Patent No. 2,275,961, issued March 10, 1942, to Herman S. Heller, for disclosure of multiple lane recording of another type, wherein but one set of magnets is provided, and provision is made for effecting relative transverse movement between said ma nets and the tape whereby recordings may be made on the different transversely spaced lanes thereof. The present invention may be regarded generally as providing improvements in multiple lane recording and reproducing apparatus of the general type disclosed in said patents. And while the present invention in certain of its aspects is broadly applicable to both of the aforementioned types of multiple lane recording, it is here specifically and illustratively disclosed in the form wherein but one set of magnets is provided and said set of magnets is arranged for relative transverse movement across the tape for selective or successive cooperation with the various recording lanes thereof. In certain specific respects, the invention deals with improvements in the last-mentioned class of multiple lane recording apparatus.

Magnet recording and reproducing machines have previously been known in which the reels and tape guides are incorporated in a portable magazine arranged for quick detachable connection to the main frame of the machine, which latter contains the drive motor, certain drivin gear, and sometimes carries the magnets. The act of mounting this magazine on the main frame automatically engages the driving gear with the reels and brings the tape into operative relationship to the magnets. In certain aspects the present invention is concerned with improvements in machines of the class having such a magazine.

Certain specific objects of the invention are as follows: to provide a means for automatically engaging and disengaging the tape from certain drive rolls permanently supported on the main frame of the machine as the magazine is mounted on or removed from the latter; to provide an improved means for closing and opening the magnets on the tape as the magazine is mounted on or removed from the main frame; to provide improvements in means for guiding the tape accurately through or past the magnet unit; to provide improved means for moving the magnet unit step-by-step transversely across the tape for cooperation with successive lanes thereof, including the provision of locking means for assuring that the magnet unit will always be positioned precisely and unwaveringly in alignment with any selected record lane; and to provide improved manually operable means for locking and unlocking the magazine on the machine, and simultaneously therewith moving the tape into operative relationship with the driving rolls and the magnets.

With this preliminary discussion in mind, the invention will be most readily understood by referring at once to the following detailed description of one illustrative embodiment thereof, reference being had to the accompanying drawin s, in which:

Figure 1 is a plan section of a sound recording and reproducing machine in accordance with the invention taken on line l-l of Fig. 2;

Figure 2 is a front elevation thereof;

Figure 3 is a view somewhat similar to Fig. 1, but considerably enlarged, and with the reels and also the portion of the machine below the magazine omitted;

Figure 4 is a view similar to Fig. 3, but showing a different position of the parts;

magnet unit on the tape, together with manually operable mechanism for operating said members;

Figure is a view similar to Fig. 9 but show- 7 ing a diiferent position;

Figure 11 is a side elevation of a portion of the manually operable mechanism appearing in plan in Figs. 9 and 10;

Figure 12 is a vertical section taken on line l2-l2 of Fig. 3;

Figure 13 is a section taken on broken line l3|3 of Fig. 12, the near magnet head being omitted;

Figure 14 is a section taken as indicated by line I4l4 of Fig. 13;

Figure 15 is a section taken on line l5l5 of Fig. 14;

Figure 16 is a section taken on line Iii-l6 of Fig. 14; Figure 17 is a horizontal section l"|-'l I of Fig. 16;

Figure 18 is a view similar to Fig. 17 but showing a different position of the parts;

Figure 19 is a transverse section taken on line l3|3 of Fig. 16;

Figure 20 is a detail section taken on line 2828 of Fig. 3:

Figure 21 is a detail section taken on line 2l2l ofFig.3;

Fig. 22 is a detail taken as indicated by line 2222 of Fig. 16;

Figure 23 is a detail taken on line cross section of the pole piece and shell, taken as indicated by line 23-23 of Fig. 14;

Figure 24 shows schematically a typical electrical circuit for the machine:

Figure 25 is a plan view of certain modifications which may be incorporated in the magazine, the magazine except for such modifications being understood to be entirely similar to the one originally described; and

Figure 26 is a detail section taken on line 28-28 of Fig. 25. a

The illustrative machine comprises a motor unit embodying a main frame or housing I having a top plate 2, and a relatively flat reel-carrying unit or magazine 3 detachably mounted on said top plate 2. Magazine 3 embodies a frame in the form of a container, preferably of plastic, and comprising bottom wall 4 adapted to rest on housing top plate 2, and a removable cover comprising top 5 and side wall 3, the lower edg of the latter being adapted to seat on a marginal upwardly facing shoulder 1 on bottom wall 4. As shown best in Fig. 5, wall 4 has a short p0- sitioning flange 8 just inside side wall 6. Setinto and projecting forwardly from flange 8-, on the forward side of the machine, are a pair of pins 8 which are engageable in corresponding apertures in the side wall 8 of the removable cover. The other side of the removable cover 5 carries a pin i0 engageable in an aperture in a flat spring ll secured to the underside of wall 4 and extending upwardly as shown in Fig. 12.

It will be evident that the cover may be removed by moving spring ll out of engagement with pin l0, and then tilting the cover upwardly and disengaging it from the pins 8 at the other s de.

The bottom wall 4 of magazine 3 has a plurality of apertures l2, here three in number, adapted to receive positioning pins l3 set into and projecting upwardly from top plate 2 of main housing I. Means later to be described are provided for locking the magazine 3 to these positioning pins I3.

As shown best in Fig. 1, the two reels i4 and II for the record medium, here a magnetic tape l6, are positioned at opposite ends and at the forward side of the magazine 3. In its course of travel between the two reels, the tape passes over and between a pair of drive rolls l1 and I8, preferably rubber faced, and positioned on axes which are in a line parallel to the line joining the axes of the reels, and spaced somewhat rearwardly and inwardly of the reels. The stretch of tape between the two rolls I1 and I8 passes between two blocks l9 and 20 constituting the magnet head and understood to carry the later described translating and erasing magnets. The tape is formed with loops 2| and 22 between the two reels and the respective drive rolls l1 and I8, and these loops pass around semi-cylindric guides 23 and 24 (Figs. 3 and 12). Each such guide consists of a semi-cylindric block 25, about which is clamped a felt strip 26, designed to smooth and stabilize the travel of the tape. Each 'block 25 has guide flanges 21 for the edges of the tape, and is mounted on a stationary plate 28 secured to a slightly elevated platform 28 formed on wall 4 (see Fig. 20)

Bottom wall 4 of magazine 3 is formed with apertures 30 to receive with clearance tape driving rolls I1 and I8. As shown best in Fig. 5, each of said tape driving rolls is mounted on a shaft 3i journalled in bearing housing 32 carried by and secured to top wall 2 of housing I, the shaft 3| having an extension 33 below housing 32 which carries a pulley 34 for a pair of drive belts 35, to be more particularly referred to hereinafter. Bottom wall 4 of magazine 3 also has openings 36, surrounded by upstanding flanges 31, to receive with clearance reel supporting and driving drums 38, the latter being formed on the upper ends of shafts 33 Journaled in bearing housings 40 secured to the under side of plate 2, and driven through over-running or one-way clutches 4| and pulleys 42 from belts 35., These over-running clutches may be of conventional character. and incorporate frictional slip devices also of well known type. {t is deemed unnecessary to illustrate or descri the specific details of such devices as they and their functions are well known in the art. For one example, see United States Patent No. 2,209,582 to Ross. It may however be stated that the one-way clutches drive the tape in one direction only, for the purpose of winding up the tape, one clutch driving and the other running freely for each direction of the tape. The frictional slip feature is a common expedient employed to permit slippage in the drive when or ii the roll of tape on the driven take-up reel becomes so great in circumference that the reel tends to wind up the tape at a faster rate than it arrives from the positively driven drive rolls. Bottom wall 4 of magazine 3 also is formed with an aperture 43 adapted to receive with suitable clearance magnet carrying blocks l8 and 23, un-

derstood to be supported and to project upwardly from main housing I.

The drive motor 44 is mounted in a vertical position in housing I, and drives main belt drive pulley 45 through suitable enclosed reduction gearing. The aforementioned belts 35 are threaded about the several pulleys 34, 42, and 4-5 as shown clearly in Fig. 8. Thus the two drive rolls l1 and 18 are directly driven from motor 44 through belts 35, while the two reels l4 and IE will be alternately driven in the proper direction through the described one-way clutches 4| depending upon the direction of drive of the belts 35. It will of course be understood that the reel toward which the tape is fed by the drive rolls l1 and 16 will always be the one which is driven through its corresponding one-way clutch, the other reel simply idling at such time.

Each of the aforementioned reel-supporting and driving drums 88 (Fig. 5) extends through and somewhat above the surrounding annular flange 31, and carries a plurality of driving pins 46 receivable in sockets 41 formed in disk 48 press fitted within a socket 49 formed in the hub 50 of the reel. The reel has a central or axial sleeve 52 which is engaged by the rounded end of a spring pressed plunger 53 working in a mounting 54 secured to the under side of container top 5. When the magazine 3 is removed from the housing I, hub disk 48 of course separates from driving drum 38, and the reel is pressed downwardly by spring pressed plunger 53 to rest on the upper end of flange 31. It will of course be understood that when the magazine 3 is mounted back on the machine, sockets 41 are engaged with drive pins 46, and as the magazine goes into position. the reel is relatively elevated against spring pressed plunger 53 to the position shown in Fig. 5.

Magnet block 20 is tightly secured to a platform 55 secured in turn to a head 56 on the upper end of a post 51, and the opposed magnet block I! is mounted on platform 55 for movement toward and from block 2!). Horizontal guide pins 58 set into block 20 and slidably received in corresponding apertures in block I9 assure precise alignment of the two blocks at all times. Magnet block 20 has at the bottom a projecting shelf portion 59 receivable in an undercut or notch 60 in the bottom of block l9, and springs 6| set into the opposed portions of said parts tend to separate the blocks from one another.

Each of the blocks l9 and 20 contains a plurality of electromagnets 62 (Figs. 14 and 16). Each of these electromagnets 62 contains an axial magnetic pole piece 63 of rectangular cross section. In the embodiment here shown, this pole piece is embedded in a plastic shell 64, of square cross section, which is slidable longitudinally or axially in an aperture of corresponding cross section extending through the electromagnet. At the forward end of the shell 64 the tip of the pole piece is exposed so that it may engage the face of the tape. The tip portion of the pole piece may typically be of a width of the order of .023 inch, while back of the extreme tip a distance of approximately 3%", the width may be increased advantageously to about .055 inch. The pole piece may be of a. thickness of 1 /2 mils. To increase the cross section of the magnetic circuit, a magnetic lamination 65 is placed along side the wider extent of pole piece 63 (Fig. 23). The plastic shell 64 is made hard enough that it will wear at substantially the same rateas the pole piece. The rear end of the shell 64 is engaged by a spring 66 which urges the pole piece into light res sural engagement with the tape. In the present embodiment of the invention, each of blocks 18 and 20 contains three of the electromagnets 62, arranged in succession longitudinally of the tape, it being understood that correspondingmagnets in the two blocks l9 and 20 are in direct axial alignment with one another. In a preferred arrangement, the two outside magnets 62 are utilized for erasing purposes, and the center magnets are translating magnets for recording and/ or reproduction.

A feature of the present invention is the provision of a tape guide comprising a pair of separable guide plates 61 and 68 normally in face to face engagement and adapted to guide the tape during its travel between the two magnet blocks I9 and 20. Thus plate 61 is formed with a tongue 69 and plate 68 with a corresponding groove 10, a longitudinal slot or guide way for the tape being formed between the face of said tongue and the bottom of said groove. For a tape of .002 inch in thickness, the guide way may be .008 inch in depth. The guide way is of such width as will receive the tape for free sliding movement therethrough. The fit is such, however, that the tape will be closely guided and will be precisely positioned by the device. Plate 68 has at the bottom a projecting foot 1| which underlines the lower edge of the plate 61, and engages downwardly against and is accurately positioned by a pair of studs 12 mounted in the top plate 2 of the housing I, as shown best in Fig. 16. The plates 61 and 68 are pressed down firmly against the positioning studs 12 by means of a flat spring 13 secured to the upper edge of the plate and engageable with the top wall of the magazine,

The two guide plates 61 and 68 are notched at the bottom, as indicated at 14, to clear the guide pins 58 and spring 6|, said notch extending the full length of the magnet blocks, as appears in Fig. 16. The downwardly projecting legs formed by the provision of this notch engage over opposite ends of the shelf portion 59 of the block 20 in such manner as to confine the plates 61 and 68 against longitudinal movement relative to the magnets, all as may be clearly understood by inspection of Fig. 16.

The end portions of tape guide plates 61 and 68 are provided with vertically elongated slots 15 through which project horizontal headed studs 16 set into posts 11 extending upwardly from bottom wall 4 of reel carrier unit 3, coil springs 16a being provided on said studs between the heads thereof and the plates, as clearly indicated in Fig. 3. The vertical elongation of these apertures 15 (see Fig. 16) assures that they will not participate in the vertical positioning of the plates 61 and 68, but the lit horizontally is relatively close and the studs 16 therefore serve to accurately position said plates in a horizontal direction. They also serve to carry these plates when the reel carrier unit is removed from the machine, at which time the plates 61 and 68 will of course be moved by spring 16a against the posts 11 (Fig. 4). It will be evident that when the magnet blocks l9 and 20 are separated (Fig. 4), or at any time that the magazine 3 is off the machine, the plate 68 may be separated from the plate 61 against the yielding opposition of springs 16a, and the tape guide way thus opened to permit insertion or removal of the tape.

Asshown best in Fig. 16, the guide plates 61 and 68 are provided with vertically elongated apertures 18 extending transversely across the tape and providing clearance for the pole pieces of the magnets in all vertical positions thereof.

It has previously been mentioned that three positioning pins I3 mounted on top plate 2 01' main housing I are receivable in apertures I2 in bottom wall ,4 of magazine 8, and that means coacting with these positioning pins locks the mesapins is provided with an annular reduction or a neck 18a (Fig. 6) which is engageable by a coacting locking means carried by the magazine. In the embodiment of the invention here shown, this locking means comprises a longitudinally reciprocative arm or bar I8, formed of sheet metal,

extending along the transverse center line of the magazine and provided near one end with an elongated slot 88 which receives the centrally located pin l3. One end of this slot 88 is engageable with the neck 18 of said pin I 3, as shown in Figs. 3 and 6, whereby the magazine 3 is locked against separation from main housing I. When the arm I8 is shifted from the position of Fig. 3 to that of Fig. 4, it is disengaged from pin I3. Underlying the other end portion of the member I8, and secured thereto as by riveting or welding, is a cross member 8|, the two extremities 82 of which, working under guides 83, project towards the two remaining pins I8, and are engageable with the reduced neck portions thereof in the locking position of the mechanism (Fig. 3). The magazine is thus locked at three points when the described locking device is in the position of Fig. 3 and is released for removalin the position of Fig. 4. The member I8 is slidably supported on a slightly elevated boss or table 84 formed on wall 4 near one end portion thereof, and is received and supported within a guide way 85 formed in the aforementioned platform 28 (see Fig. 20). The arm I8 is also supported, in the area of its slot 88, in a guide way 88 formed in a slightly elevated table 81 formed on the wall 4 (Figs. 6 and 21) a strap or bridge member 88 mounted on the member 81 overlying arm 18 and being apertured at 88 to receive pin I3.

Attached at one end to plate 81 is a spring arm 88 carrying a pin 8| which is engageable in an aperture 82 in arm I8 when the latter is in the position of Fig. 4. A pin 88 projecting upwardly from top 2 of main housing I and receivable through a suitable aperture in the bottom of unit 8 (Fig. 21) is engageable with the free end of this spring arm 88 when the magazine 8 is mounted on housing I, acting at such times to lift said arm to the position'of Fig, 21, wherein pin 8I clears the upper side of arm I8. When the arm I8 is moved to the unlocked position of Fig. 4, pin 8I registers with aperture 82, and when the magazine is then lifted from housing I, spring arm 88 moves downwardly flush against plate 88, causing pin 8| to engage in aperture 82 and thus lock the arm I8 and the various members controlled thereby in the position of Fig. 4.

The means for shifting the arm 18 between the positions of Figs. 3 and 4 will next be described. Arm I8 is formed with a cross slot 84, which receives a crank pin 85 projecting upwardly through an arcuate slot 88 in wall 4 from a crank disk 81 8 rotatably mounted in the top of main housing I as shown in Fig. 6. Projecting downwardly from crank disk 81 is a pin 88 carrying a crank arm v 88, and the latter is pivotally connected by link I 88' to a crank arm IN on a shaft I82 rotatably mounted in the top of housing I, said shaft I82 having connected thereto an operating handle I88 which is at an elevation just above the upper side of the magazine 3 (Fig. 2). Operation of handle I83 between the two positions indicated in Figs. 9 and 10 acts through arm I M and link I88 to move crank arm 88 and crank pin 85 between the positions of Figs. 9 and 10, the crank pin 85 thus operating to shift the locking device between locking position (Fig. 9) and unlocked position (Fig. 10).

The described movement of arm I8 is also utilized to perform other functions, one of which is to shift the removable magnet block I8 into operative position as the magazine 8 is locked to the machine. For this purpose, arm I8 has at its rearward end spaced extensions or legs I84 terminated by upwardly turned feet I85 adapted to engage the side of the magnet block I8 to move it from the open position of Figs. 18 and 4 to the closed position of Figs. 3 and 9. It will be recalled that the block I8 is normally urged to separate from the block 28 by virtue of the springs 6|, and the block I8 accordingly moves away from' block 28- under the influence of these springs when arm I9 is shifted to the position of Fig. 4 to unlock the magazine. Thus the magazine being unlocked, the magnet blocks I9 and 28 are automatically separated; the tape guide unit consisting of plates 61 and 68 backs up against the posts II at such time, to a position free and clear of the pole pieces, and the magazine may be lifted from the machine.

The other function performed by the arm 18 in moving longitudinally between the positions of Figs. 3 and 4 is to move the tape into and out of operative engagement with the drive rolls II and I8. A pair of links I86 are pivotally connected to arm I8, as at I 81, and said links I88 are pivotally connected to links I88, the latter being pivotally connected at I88 with a pair of swinging arms II 8 that are in turn pivotally mounted at their ends on magazine bottom wall 4 near the forward edge thereof, as shown at III. Arms II 8 extend under and beyond the stretch of the tape extending between guides 25 and the corresponding drive rolls, and have upwardly turned projections II 2, surrounded by rubber sleeves II3, adapted for gripping engagement with the tape. The other ends of links I88 are pivotally connected to arms H4 arranged for longitudinal movement with reference to arms II8. Thus, the arms II4 may have longitudinal slots II5 receiving pins II 6 projecting upwardly from arms H8. The forward ends of arms II4 are provided with upwardly turned portions II'I, enclosed by rubber sleeves II8, adapted to grip the opposite face of the tape, i. e., the face opposite to that gripped by the member II2. That is to say, the tape passes between the two members H2 and Ill, and may be gripped or pinched therebetween. In the position of Fig. 3, the members H2 and II I are both separated from the tape. When arm I8 is moved from the locking position of Fig. 3 toward the release position of Fig. 4, links I88 at first are restrained against swinging outwardly by an interconnecting spring 8, and function to swing links I88 so as to move arms II4 longitudinally relative to arms I I8, thereby causing tape gripping elements III to magnet carrying post 51 tion, while engage the tape and press it firmly against elements II2. In this movement. the elements II1 firm grip on the tape, the rubber sleeves assuring a non-slipping engagement. The members H1 and I tape, further travel of arm 19 toward the position of Fig. 4 causes the links I06 to spread further apart, and, acting through links I08, to swing t e two arms IIO outwardly. Thereby the tape. g ipped between elements H2 and H1, is moved outwardly and away from drive rolls I8 and I1, as to the position of Fig. 4, from which it will be observed that the tape has entirely cleared The parts then being in the position of Fig. 4, with the magazine unlocked from the machine. drive rolls I1 and I8, the magazine may readily be lifted from the machine. Pins I set into the bottom of the magazine cooperate in supporting the tape out of contact with the and I8 in the position of Fig. 4.

The aforementioned post 51 which carries the magnet head (Fig. 14) is in the form of a cylindrical shaft provided with a working fit in a bushing I2I set into a frame I22 secured within housing I, the bushing I2I having at its upper end a head flange I23 resting down on horizontal surface I24 of frame I22. A stud I25 set into frame I22 has at its inner end a projecting through tical splineway I28 cut in to prevent rotation of the latter while permitting longitudinal travel thereof. Screwed into the bottom end of post 51 is a stud I29 (Fi 16) carrying below the lower end of bushing I2I a flange I30 of a diameter somewhat larger than said bushing, and projecting downwardly below the latter is a cam follower pin I3I having a rounded lower end I32 bearing on the periphery of a stepping cam I33. The cam I33 is mounted on a horizontal shaft I34 'journa ed at opposite ends in depending extensions I35 and I36 of frame I22.

' The aforementioned surface I24 of frame I22 is the top surface of a bridge-like member I31, and the latter has, somewhat above the lowermost end of bushing I2I, a downwardly facing horizontal surface I38. Surrounding the bushing I2I and engaging this surface I38 is a flat washer I39. and against washer I39 and surrounding bushing I2I is an annulus I40 which serves as a carrier for certain presently described locking devices. This annulus I40 has a reduced downwardly proiecting sleeve-like portion HI, and confined between the lower end of the latter and the aforementioned flange I30 is a coil compression spring I42. the latter encircling the lower end portion of bushing HI. and acting downwardly on flange I30 to maintain cam follower I3I in spring-urged engagement with cam I33. The spring I42 thus tends constantly to urge the in a downward directhe cam I33 lifts the post 51 against the yielding opposition of said spring. As clearly appears in Fig. 14, the described annulus I40 is secured to frame bridge I31 by means of long screws I43.

Cam I33 and shaft step. by a mechanism I34 are rotated. step by including a ratchet wheel I44 mounted on shaft I34 and a pawl device I45 reciprocated in a vertical direction by a solenoid I46. Solenoid I46 is mounted on a frame plate I41, hung from frame I22 by means of strap I48. It has a vertically reciprocative plunger I49, to

rolls I1 are radial with 10 which is secured the horizontal leg of the L-shaped pawl device I45, the vertical ing a vertically elongated slot I50 (see Fig. 12) engageable over the successive. ratchet teeth I5I of ratchet wheel I44. There being eight recording lanes in the present embodiment of the invention, the ratchet wheel is provided with eight ratchet teeth I5I. Between successive teeth I5I formed slots I52, the defining side walls of which respect to the axis of the ratchet wheel, and form the ends of the two adjacent teeth. The lands I53 of the teeth I5I are preferably substantially tangential with respect to the radii of the ratchet wheel, as clearly shown in Fig. 16. On the upstroke of the pawl device I45, the pawl slot will ride of! the ratchet tooth which down, and when the slot I50 has cleared the tooth just above, will spring inwardly shown in Fig. 16. On the subsequent downward movement, the ratchet tooth thus engaged will be drawn downwardly. -To limit the downward travel of the pawl, so that the ratchet wheel will be rotated through substantially 45 (one-eighth of a revolution), a bracket I51 is secured to the upper end of solenoid plunger I43, being arranged to extend upwardly adjacent and somewhat beyond the upper side of the ratchet wheel. A vertically elongated slot I58 is provided to pass the shaft I34. At the top of this bracket I51 is a turned over lug I53, arranged to overlie the ratchet wheel. This lug I59 engages the land I53 of one of the uppermost ratchet teeth when the solenoid plunger and pawl have descended sumciently to rotate the ratchet wheel through precisely 45. When the solenoid plunger subsequently rises, a locking pin I60 carried by bracket I51 engages in the lowermost ratchet wheel slot I52 to limit the upward travel of the mechanism, and at the same time to lock the ratchet wheel against rotation. This locking pin I50 has dropped sufficiently to clear the slot I52 by the time the downwardly travelling pawl device I45 strikes the upper end of the ratchet tooth with which it is engaged, so

that the ratchet wheel is unlocked just prior to its being picked up by the pawl.

The aforementioned stepping cam I33 has eight constant radius of successively inclockwise direction, as viewed in eighth of these lands, commencing with radius, are connected by somewhat sharply sloping risers I62. The last or eighth land I'6I is connected with the first by a radial drop-of! shoulder I63.

It will of course be understood that the solenoid plunger I49 is lowered to operate the pawl device I45 as above described when the solenoid is energized. When the solenoid is de-energized, it is elevated back to its normal position by means of a coil compression spring I04 encircling the plunger I49 between the top of the solenoid and the horizontal leg of pawl device I45 secured to the upper end of the solenoid plunger.

As will be seen from an inspection of Fig. 16, the cam follower pin I3I is in engagement with about the mid-point of a land I6I of stepping cam I33 when ratchet wheel I44 is at rest. Energization of solenoid I46 causes the ratchet wheel to be advanced through a 45 arc, and at about the midpoint of its travel, follower pin I3I is engaged by a cam riser I62 and elevated by one step. Itbeing understood that the cam I33 rotates step-by-step in a counterclockwise direction as viewed in Fig.

are

means 1 I 16, the cam risers I82 are so dimensioned as to enslots I82, thereby removing the locking teeth I88 gage and lift the cam i'ollower pin I3 I, and therefrom slots I8I. The' ring I18 is so moved by means fore the magnet head, by a distance equal to the of its projecting pins I18 and the bell crank I68 predetermined center-to-center spacing of the earlier described (Fig. The position shown A feature of importance is the provision of a opposition of a flat return spring I88. Thus the locking device which positively locks the magnet bell crank is rocked to release the locking elements number of teeth I68 equal in number to the numalternatively, drops past the shoulder I68, the

ceive an actuating pin I13 projecting radially the influence of spring I 85, into a notch between from a ring I14 rotatably mounted on the reduced teeth. Bell crank I 68 thus swings back to the full sleeve portion III of annulus I40, said ring I14 beline position oi. Fig. 15, shifting locking elements ing confined between downwardly facing shoulder I19 into the locking position 01' Fig. 17.

I16 on annulus I88 and retaining ring or washer A lever I86 is pivotally mounted at I81 within I18 secured to sleeve member I I as by snap ring a slot I88 in frame member I22 (Fig. 14) and has I11. Sunk in the upper side of annulus I88 is an upwardly extending arm I88 projecting a diametrical way or slot I18, wherein are slidably through opening 43 in magazine wall I, the upper Similar spac d t e h h e ei h in m e which buttons I9I mounted on brackets I82 secured to are engageable in corresponding slots I8I formed plate 23 bear on the ther face of the tape, di-

in the post 61. For convenience, these slots I81 rectly opposite the buttons I88. The lower arm that there will be a complete set of grooves in pass freely therebetween. The tape is provided opposition to the locking teeth I 80 in all vertical near a h of it ends with a thickened portion positions 01 adjustment of the post 51. Fig. 16 I96 0! some extent longitudinally of the tape, as showing the post 51 in its uppermost position, indicated in Fig. 3. When this enlargement or above the locking element I19 for that position. buttons I86 and I8I, the lever I86 is swung ashort The center-to-center spacing of the teeth and of distance, pressing inwardly on micro-switch butthe corresponding grooves is made equal to the 55 ton I88 and actuating the latter. This microdistance the post 51 is elevated on each actuation switch is employed in a presently described electance of the recor ing lanes on the tape. Each I85 is of a conventional spring pressed type, yieldsuitable arcuate slots I85 formed in the portion of position of Fig. 14.

the annulus I48 directly below the slot I18. Reference is next directed to Fig. 23 showing In the position of Fig. 17, the locking elements schematically an electrical circuit for the machine I18 are in their inward positions, and their locking as above described. Fig. 24 shows two decks I81 teeth I88 are inserted snugly in the grooves" I8I and I88 of a switch operated by the previously dein post 61, so as to lock the latter rigidly against scribedratchet-driven shaft I38, and which apthe slightest vertical movement. Rotation oi the pear in side elevation in Fig. 12. Each deck con- 201 is adapted to sweep successively over switch contacts carried by an insulation stator 202 which may be mounted on the machine as in the manner illustrated in Fig. 12. The several switch contacts carried by the stator are spaced 45 apart, and contact is made therewith successively as the shaft [34 is ratchet-driven through successive 45 movements. In addition, there is a brush, numbered 203 in the case of deck I91, 204 in the case of deck 1'98, mounted on the stator and contacting at all times the collector ring on the rotor.

Figure 24 shows conventionally the three pairs of electromagnets 82, the center pair being translating magnets for recording and/or reproduction, and the two outside pairs being erasing magnets. Each such pair is electrically connected 'in series, and one end of each pair is grounded, as indicated at 205. The ungrounded end of the .translating magnets is connected by lead 206 to the contacts 201 and 208 of a gang switch generally indicated by numeral 209. Opposed to switch contact 201 is a switch contact 210 connected to microphone jack 2| l, a switch arm 2l2 being movable to make with either contact 201 ,or contact 210. Switch arm 212 is connected by lead 213 to the input terminal of amplifier 2. :The output terminal of amplifier 2 is connected by lead 2l5 to movable switch arm 2i9 adapted to make alternately with contact 208 and with a switch contact 2|1 opposed to the latter, and said contact 211 is connected by lead :2l8 to speaker 219. It is to be understood that switch arms 2 l2 and 210 are interconnected so as to move together, being in contact with contacts 1m and 208, respectively, for the "Record position, and with contacts 201 and 211, respectively, for "Reproduce." In the Record" position, the microphone, not shown, is connected to microphone jack 2| l, and a circuit is formed including switch contact 210, switch arm 212, and lead 2I3 to the input end of the amplifier. and from the output of the amplifier via lead 215, switch arm 2l6, contact 208, and lead 208 to the translating magnets 62. cuit with the microphone, and the machine is in condition for recordation. In the Reproduce .position, the translating magnets are connected by lead 206, switch contact 201, contact arm 212, and lead 2l3 to the input end of the amplifier, and from the amplifier output via lead 215, switch arm 219, switch contact 211, and lead 218 to speaker 2l9. Thus the translating magnets are in circuit with the speaker.

The reversible drive motor 44 is indicated in Fig. 24 as of a split phase capacitor type, having four external leads 220, 221, 222, and 223, two for each phase. Numeral 224 designates a source of alternating current power, and one side thereof is connected by lead 225 and lead 220 to one phase of motor 44, the other side of-the same phase of the motor being connected by lead 222 and lead 229 to the other side of the power source through motor on-and-ofi switch 221. A lead 228 branching from lead 229 is connected to a movable switch arm 229, switch contact 230, and .lead 231 to motor lead 223 connected to the other phase of motor 44, while the other side of the last-mentioned phase is connected by lead 221, switch contact 232, movable switch arm 233, and lead 234 to power lead 225 leading back to the .power source. Thus both phases of the motor are across the power source. The two movable switch arms 229 and 233 are operated by a solenoid 235 which when energized holds them in the position .shown in Fig. 24. The switch is of the type such The magnets are accordingly in cir- 'to the other, whereby the that when the solenoid 235 is de-energized, switch arms 229 and 233 make with contacts 238 and 231, respectively. Contact 239 is connected to motor lead HI, and contact 231 is connected to motor lead 223. It will be evident, therefore, that when the switch is in the alternative position, that is, with switch arms 229 and 233 against contacts 238 and 231, respectively, the one phase of the motor 44 is reversed in polarity with respect direction of rotation of the motor is reversed. Hence, energization and de-energization of the solenoid effects drive of the motor in one direction or the other, thereby accomplishing drive of the tape in one direction or the other.

Solenoid 235 is connected by lead 238 to a movable switch arm 239 of a manual reverse switch 240, switch arm 239 being normally in contact with switch contact 241 connected by lead 242 to alternate stator switch contacts 243 of switch deck 198. The switch rotor being in a position such that its contact 201 is in engagement with one of the switch contacts 243, the circuit is closed via collector ring 200, brush 204 and lead 244. Hence with the rotor of switch deck I98 in any position with its contact arm 201 in engagement with one of the contacts 243, solenoid 235 will be energized and the motor will drive in one direction.

Manual reverse switch 240 includes a movable switch arm 245 and an opposed contact 248, the arm 245 normally being out of contact with contact 248. Switch arms 239 and 245 are interconnected, in such manner that when the manual reverse switch is operated, switch arm 239 breaks from contact 2 and switch arm 245 makes with contact 246. Upon release, the switch returns to the position indicated. Switch arm 245 is connected by lead 241 to the remaining switch contacts 248 on the stator of switch deck I98. Switch contact 246 is connected by lead 249 with movable switch arm 239.

Assuming now that the switches are in the position of Fig. 24, with the motor driving the tape in one direction. If at any time it should be desired to back track along the tape, manual reverse switch 240 is operated. Switch arm 239 is then separated from switch contact 241, so that the switch contacts 243 of switch deck I98 are open circuited. Solenoid lead 238 is at such time connected by a lead 249, switch contact 246 and switch arm 245 to stator contact 248 of switch deck 108, but in the present position of the switch rotor, said contacts are open circuited. Solenoid 235 is accordingly de-energized, and the motor 44 will be reversed in the manner previously described.

Assume next that the switch deck rotor has been shifted into a position wherein its contact 201 makes with one of contacts 248. Solenoid 235 will accordingly be de-energized, since contacts 243 are open circuited. To effect a manual reverse, reverse switch 240 is depressed. Solenoid 235 is now connected by lead 238, lead 249, switch contact 246 and arm 245 to lead 241 and thence to switch contacts 248. The circuit is completed from there through rotor contact 20l and brush 204 to return lead 244. The solenoid is therefore energized, and the result of depressing the manual switch has been to reverse the direction oi the motor.

It will thus be seen that as the previously described ratchet and pawl mechanism operates to shift the machine from one recording lane to the next, it at the same time moves switch rotor I33 ahead step by step, thereby revers h direction of drive of the tape for each shift from one lane to the next. Thus a recording having been completed on one lane of the tape, and the machine operating to shift to the next or adjacent lane thereof, the motor automatically reverses direction so as to drive the tape in the reverse direction, and the recording is thus accomplished on successive lanes with the tape driving in first one direction and then the other. And at any time the direction of rotation of the drive motor may be reversed to back track along the tape without shifting from lane to lane by operation of the manual reverse switch 240, as previously described.

The stator of switch deck I91 has one set of switch contacts 250, and a set of intervening contacts I, adapted to be swept successively by the switch arm 26I of the corresponding rotor. The contacts 250 are connected by lead 252 to one set of erasing magnets, and contacts 25I by lead 253 to the other set of erasing magnets. A high frequency oscillator 254, which constitutes the source of erasing current, has one output lead 255 connected to brush 203 bearing on the collector ring 200 of the switch deck I91. It will be evident that the oscillator output lead 255 is alternately connected to one set of erasing magnets and then the other as the switch rotor is stepped ahead in consonance with the stepping operation of the previously described pawl and ratchet mechanism. To complete the oscillator circuit to the erasing magnet, the other oscillator output lead 256 is connected to a switch contact 251, contacted by a movable switch arm 258, which latter is connected to ground. The contact 251 and switch arm 258 are a part of the gang switch 209, switch arm 258 making with contact 251 when the switch is in the Record" position, and opening the oscillator circuit to ground in the Reproduce positlon. Thus during the recording operation the other oscillator output terminal is connected to ground through the described switch, thereby completin the circuit. Connections are so made that during recording with the tape I6 travelling toward the right, as viewed in Fig. 24, the lefthand erasing magnet will be energized through the switch I 91; and with the tape travelling in the opposite direction, the right-hand erasing obliterates any past history thereon, and then the recording magnet, the remaining set of erasing magnets being open circuited at the time. For the "Reproduce" position of switch 209, the oscillator circuit is open at switch 209.

Fig. 24 also shows the stepping solenoid I48 which actuates the pawl and ratchet mechanism to move the magnet head from lane to lane, as well as, through shaft I36, to move the rotors of switch decks I91 and I98 ahead step by step, as indicated by the dash lines in Fig. 24. The solenoid I46 is shown as connected by one lead 259 to one side of the power source, and by a lead 260 to one side of the aforementioned micro-switch I95 previously described as actuated by the tape. The other side of said micro-switch I95 is connected by lead 26I and lead 225 back to the other side of the power source. The solenoid is thus energized to perform the various functions already described by closure of micro-switch I95, and it has already been described how'this micro-switch may be closed by enlargements formed on the Any other means for by the tape may of an indicator device 262 embodying an arm 263 pivotally mounted as at 266 on a bridge member 265 and urged by a coil spring 266 to bear constantly on the periphery of the tape roll 261 on one of the reels. Pivotally connected to the front end of arm 263 is a scale sector arm 268 provided with a scale 269 which is visible through the transparent top wall of the magazine. The arm 268 is yieldingly positioned normally in the full line position with respect to arm 263 by means of a spring-pressed detent 216 carried by the arm 268 and engageable in a suitable hole in the am 263. A fixed indicator line 21I inscribed or engraved on the transparent top wall of the mazezine above scale 269 cooperates with said scale 269 and permits the obtainment of reference numerals by which any desired point of the recording on the tape may subsequently be quickly found. To permit the reels to be removed from the magazine, it is necessary to fold the arm 26 against the arm 263, as to the dot-dash position of Fig. 25. Accordingly, the arm 269 is pivotally swung to the folded position indicated, and a hole 212 in arm 263 is at that time engaged by springpressed detent 210. Thus, the arm 269 will be yieldingly supported in the position shown in dotdash lines. A spring 213 mounted within the magazine may be engaged by the end of the arm 263, supporting said arm in a position clearing the reel I5, as will be readily understood.

The drawings and description are, of course, to be taken as illustrative of one present embodiment of the invention, and it will be understoodthat various changes in design, structure, and arrangement may be made without departing from the spirit and scope of the invention or of the appended claims.

I claim:

1. In a recording machine employing a record tape, the combination of a. motor unit embodying a housing, a drive motor in said housing, a rotatable drive roll mounted on and projecting from one side of said housing, means driving said drive roll from said motor, and a separable magazine unit adapted for quick demountable attachment to said side of said housing, said magazine adapted to receive said drive roll, locking means on said magazines for locking said magazines to said motor unit, record tape supporting means within said magazine, and means operable by said locking means for moving said tape into and from a position of peripheral driving engagement with said drive roll.

2. In a recording machine employing a record tape, the combination of a motor unit embodying a housing, a drive motor in said housing, a rotatable drive roll mounted on and projecting from one side of said housing, means driving said drive roll from said motor, and a separable magazine unit comprising a container adapted for quick demountable attachment to said side of said housing, said container having an aperture adapted to receive said drive roll, record tape supporting and guiding means in said container including 17- means forming a loop around said tape drive roll, and tape engaging means embodying a pair of gripping elements operable to grip opposite faces of said tape at one side of said loop and to move said loop while the tape is so gripped out of or netic'record tape, the combination of a means supported on said machine for supporting and V guiding a record tape for longitudinal movement into peripheral driving engagement with said drive roll.

' 3. In a recording machine employing a record tape, the combination of a motor unit embodying a housing, a drive motor in said'housing, a ro' tatable drive roll mounted on and projecting from one side of said housing, means driving .a pair of gripping elements operable to grip'opposite faces of said tape at one side of said loop and to move said loop while the tape is so gripped out of or into peripheral driving engagement with said drive roll, said gripping elements being carin a predetermined path, a pair of translating magnets positioned on opposite sides of said tape moving in said predetermined path, a pawl and ratchet means for shifting said magnets transversely of said tape to successive positions across the tape whereby recordings may be made on diflerent non-overlapping longitudinally extending lanes of said tape, locking means for positively locking said magnets in each of said successive positions, and means for automatically unlocking and locking said locking means during initial and terminal portions of the movement of said pawl.

.7. In a recording machine employing a magnetic. record tape, the combination of a frame, a

translating magnet unit embodying a pair of opposed separable translating magnets with projectingpole pieces supported on said frame, and

" atape guide means accurately positionable in a predetermined fixed operating position between said magnets embodying a pair of separable guide j plates extended longitudinally of the tape and ried one by an arm pivoted on said container and one carried by and longitudinally movable with respect to said arm.

4. In a recording machine employing a magnetic record tape, the combination of a main pair of opposed separable translating magnets with projecting pole pieces supported on and projecting from one side of said housing, a separable magazine unit comprising a container adapted for quick demountable attachment to said side of said housing, said container being adapted to receive said magnet unit when so attached to said housing, a tape gui 'e means supported in said container and receiva le between said separable magnets, said tape guide means embodying a pair of separable guide plates having a longi- 30 housing, a translating magnet unit embodying a formed with a longitudinal tape guide way therebetween which closely guides the edges of said tape, said guide plates being cut away opposite said pole pieces to permit contact of the polepieces with the tape, and said separable magnets being closeable on said guide plates.

8. A combination as defined in claim 7, wherein one. edge of said tape guide means engages fixed positioning abutment means.

tudinal tape guide way formed therebetween, said guide plates being apertured opposite said pole pieces of said magnets to permit contact of the pole pieces with the tape, and said separable magnets being closeable on said guide plates, supporting pins mounted in said container projecting at right angles to said guide plates through apertures therein which are elongated transversely of the tape guide way, springs on said pins en.- gaging one side of said plates, and abutment means on the other side of said plates engageable by said plates under the pressure of said spring when said magnets are separated, said abutment means supporting said plates in a position of clearance with reference to said pole pieces of said magnets when said magnets are separated.

5. In a recording machine employing a magnetic record tape, the combination of a means supported on said machine for supporting and guiding a record tape for longitudinal movement in a predetermined path, a pair of translating magnets positioned on opposite sides of said tape moving in said predetermined path, step-by-step means for shifting said magnets transversely of said tape to successive positions across the tape whereby recordings may be made on diilerent. non-overlapping longitudinally extending lanes of said tape, locking means for positively locking said magnets in each of said successive positions, and means for automatically unlocking said locking means upon each actuation of said step-bystep means.

6. In a recording machine employing a mag '9. A combination as defined in claim 7, where -in-one edge of said tape guide means engages fixed positioning abutment means, and spring means urging said tape guide means against said abutment means.

1 0.1A combination as defined in claim 7, in which means are provided supporting said tape guide plates for movement as a unit in directions at right angles to the plane of the tape during openingand closing movements of said separable magnets.

11. In a recording machine employing a magnetic record tape, the combination of a frame, means supported on said frame for guiding a tape in a predetermined path. a pair of opposed translating magnets with projecting pole pieces positioned on opposite sides of said predetermined path of said tape, means supported on said frame for shifting said magnets transversely across the tape, and a tape guide means accuratelypositioned in a predetermined fixed operating position between said magnets embodying a pair of separable guide plates extended lon itudinally of the tape and formed with a longitudinal ta e guide way therebetween which closely guides the edges of the tape, said guide plates being apertured opposite said pole pieces to permit contact of the pole pieces with the tape throughout all transverse positions of the magnets.

'12. A separable magazine unit for the record tape of a sound recording machine having a motor unit, a drive motor mounted thereon. and tape drive roll means adapted for peripheral engagement with the record tapemounted thereon and driven by said motor, that comprises: a

ma azine frame adapted for detachable connection with said motor unit. means on said frame for-supporting a record tape, locking means for locking said magazine frame to said motor unit. and means on said frame operative in consonance with said locking means when said frame is nositioned on' said motor unit for moving said tape between a position of peripheral engagement with said drive roll means and a position clearing said drive roll means.

13. In a recording machine employing a record tape, the combination of a motor unit embodying a housing, a drive motor in said housing, a rotatable drive roll mounted on and projecting from one side of said housing, means driving said drive roll from said motor, and a separable magazine unit adapted for quick demountable attachment to said side of said housing, said magazine adapted to receive said drive roll, and record tape supporting and guiding means in said magazine including movable tape gripping means engageable with opposite faces of the tape for gripping a portion of said tape and moving it into peripheral driving engagement withsaid drive roll or backing it oi! therefrom.

14. A recording machine as defined in claim 1, in which said tape gripping means embodies a pair of gripping elements operable to grip opposite faces of the tape at a point spaced from said drive roll while said tape is in engagement with said drive roll and to move the gripped portion of the tape in a direction to back the tape out of engagement with said drive roll.

15. In a recording machine employing a magnetic record tape, the combination of a main housing, a translating magnet unit embodying a pair of separable translating magnets supported on and projecting from one side of said housing, a separable magazine unit adapted for quick demountable attachment to said side of said housing, means in said magazine for guiding a record tape therein between said two magnets, locking means on said magazine operable to positively lock said magazine to said housing after it has been attached thereto, and means for closing said magnets on said tape by virtue of locking operation of said locking means and for separating said magnets by virtue of unlocking operation of said locking means.

16. In a recording machine employing a record tape, the combination of a motor unit embodying a housing, a drive motor in said housing, a rotatable drive roll mounted on and projecting from one side of said housing, means driving said drive roll from said motor, a translating magnet unit embodying a pair of separable translating magnets supported on and projecting from said side of said housing, a separable magazine adapted for quick demountable attachment to said side of said housing, means in said magazine for guiding a record tape therein past said tape drive roll and between said pair of magnets, and unitary magnet operating and tape moving means operable only after said magazine is attached to'isaid housing to close said magnets on said tape and to move said tape into a position of peripheral driving engagement with said tape drive roll, and also operable to separate said magnets and to back said tape of! said driving roll preparatory to removal of said magazine from said housing.

1'7. In a recording machine employing a record tape, the combination of a motor unit embodying a housing, a drive motor in said housing, a rotatable drive roll mounted on and projecting from one side of said housing, means driving said drive roll from said motor, a translating magnet unit embodying a pair of separable translating magnets supported on and projecting from said side of said housing, a separable magazine adapted for quick demountable attachment to said side of said housing, means in said magazine for guiding a record tape therein past said tape drive roll and between said pair of magnets, locking means for locking said magazine to said housing aiter the magazine is attached thereto, and meansoperable in conjunction with said locking means for supporting said tape in peripheral contact with said drive roll and for closing said separable magnets on said tape only while said magazine is locked to said housing by said locking means.

18. In a recording machine employing a magnetic record tape, the combination of a main housing, a translating magnet unit embodying a pair of opposed translating magnets with projecting pole pieces supported on and projecting from one side of said housing, a separable magazine adapted for quick demountable attachment to said side of said housing, a tape guide means supported by said magazine and receivable between said magnets, said tape guide means embodying a pair of separable guide plates having a longitudinal tape guide way formed therebetween, said guide plates being apertured opposite said pole pieces or said magnets to permit contact of the pole pieces with opposite faces of the tape, and said pole pieces being arranged for relative movement toward and from said apertured guide plates to permit insertion into and withdrawal from said apertured guide plates.

19. In a recording machine employing a magnetic record tape, the combination of a main housing, a translating magnet unit embodying a pair of opposed separable translating magnets supported on and projecting from one side of said housing, a separable magazine adapted for quick demountable attachment to said side or said housing, a tape guide means floatingly supported on said magazine, fixed abutment means on said main housing engaged by the bottom edge of said tape guide means, and spring means on said magazine acting downwardly on said tape guide means to assure accurate positioning thereof against said abutmentmeans.

20. In a recording machine employing a magnetic record tape, the combination of a means supported on said machine for supporting and guiding a record tape for longitudinal movement in a predetermined path, a pair of translating magnets positioned on opposite sides of said tape moving in said predetermined path, step-by-step means for shifting said magnets transversely of said tape to successive positions across the tape whereby recordings may be made on different non-overlapping longitudinally extending lanes of said tape, and locking means for positively locking said magnets in each of said successive positions, said step-by-step means including a ratchet wheel, a pawl for operating said ratchet wheel, a cam operable by said ratchet wheel, and a cam follower for moving said magnets, said cam operating'to move said cam follower during an intermediate portion of each movement of said cam, and said locking means operating in consonance with said pawl to move to unlocking and locking positions during the initial and terminal portions of each driving stroke of said pawl.

21. In a recording machine employing a magnetic record tape, the combination of a means supported on said machine for supporting and guiding a record tape for longitudinal movement in a predetermined path, a pair of translating magnets positioned on opposite sides of said tape moving in said predetermined path, step-by-step means for shifting said magnets transversely of said tape to successive positions across the tape whereby recordings may be made on diflerent non-overlapping longitudinally extending lanes oi said tape, said step-by-step means including a ratchet wheel, a pawl for operating said ratchet wheel, a cam operable by said ratchet wheel, a cam follower for moving said magnets, and looking means for positively locking said magnets in each of said successive positions.

22. A recording and reproducing machine employing a record tape, including a motor unit embodying a main housing and a drive motor and driving gear powered thereby in said main housing, a separable magazine for record tape adapted for quick demountable attachment to said housing, a pair of translating magnets mounted on said housing to be received in said magazine when said magazine is mounted on said housing, said magazine including means for supporting a record tape therewithin for travel between said translating magnets, tape drive roll means powered by said driving gear and adapted to operate within said magazine to drive said tape past said translating magnets, said magazine also including tape guide means for guiding the tape between said translating magnets, said tape guide means being floatingly mounted in said magazine, and fixed abutment means on said housing engaged by said tape guide means when the magazine is mounted on the housing to accurately position the tape guide means relative to the translating magnets.

23. A machine according to claim 22, including spring means for holding said tape guide means accurately positioned against said abutment means.

24. A machine according to claim 22, in which said tape guide means comprises a pair of guide plates formed therebetween with a longitudinal guideway for the tape and receivable between the magnets, spring means engaging said guide means to position it against said abutment means, projecting spring-urged pole pieces included in said magnets adapted to bear on opposite sides or the tape, said guide plates being apertured opposite said pole pieces to permit engagement of the pole pieces with the tape, and said pole pieces being retractable to permit insertion or removal of the guide plates to or from their position between the magnets.

HERMAN S. HELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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