US3849797A - Video transducer system and cartridge therefor - Google Patents

Video transducer system and cartridge therefor Download PDF

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Publication number
US3849797A
US3849797A US00282275A US28227572A US3849797A US 3849797 A US3849797 A US 3849797A US 00282275 A US00282275 A US 00282275A US 28227572 A US28227572 A US 28227572A US 3849797 A US3849797 A US 3849797A
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Prior art keywords
capstan
tape
flywheel
brake
cartridge
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00282275A
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English (en)
Inventor
M Camras
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ITT Research Institute
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ITT Research Institute
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Publication date
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Priority to US00282275A priority Critical patent/US3849797A/en
Priority to US05/346,869 priority patent/US4020999A/en
Priority to DE19732331164 priority patent/DE2331164C3/de
Priority to CA174,665A priority patent/CA1033058A/en
Priority to JP48093783A priority patent/JPS5821341B2/ja
Priority to NL7311500A priority patent/NL7311500A/xx
Application granted granted Critical
Publication of US3849797A publication Critical patent/US3849797A/en
Priority to US05/533,485 priority patent/US4032985A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
    • G11B23/02—Containers; Storing means both adapted to cooperate with the recording or reproducing means
    • G11B23/04—Magazines; Cassettes for webs or filaments
    • G11B23/06—Magazines; Cassettes for webs or filaments for housing endless webs or filaments
    • G11B23/07—Magazines; Cassettes for webs or filaments for housing endless webs or filaments using a single reel or core
    • 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
    • G11B15/1883—Driving; Starting; Stopping; Arrangements for control or regulation thereof for record carriers inside containers
    • G11B15/1891—Driving; Starting; Stopping; Arrangements for control or regulation thereof for record carriers inside containers the record carrier being endless
    • 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
    • G11B15/43—Control or regulation of mechanical tension of record carrier, e.g. tape tension
    • 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
    • G11B15/60—Guiding record carrier
    • G11B15/66—Threading; Loading; Automatic self-loading
    • G11B15/665—Threading; Loading; Automatic self-loading by extracting loop of record carrier from container

Definitions

  • ABSTRACT A video tape cartridge of endless loop configuration capable of tape speeds of 120 inches persecond while providing one hour or more of continuous playing time on A inch width tape.
  • the tape drive is steady enough so that the reproduced signal can be coupled to the antenna circuit of a home television receiver without modification of the conventional synchronizing circuits.
  • This invention relates to a cartridge type video transducer system, and to an endless loop magnetic tape cartridge for use in such a system.
  • a further object is to provide an endless loop cartridge and transport therefor capable of providing record tape speeds as high as 120 inches per second or more, if desired, with a desired low degree of tape flutter at the transducer head.
  • Another object is to provide an endless loop transducer system capable of providing one hour or more of playing time in conjunction with a conventional broadcast television receiver, while utilizing only a single non-rotating transducer head, and preferably with the use of a gradual shifting of the head in the lateral direction in moving between longitudinal tracks on the tape 7 to avoid any discontinuity in the playback process.
  • a still further object of the invention is to provide a simple and economical cartridge type video transducing system having very few moving parts and compact configuration, and yet which provides an extremely steady tape motion at the transducing location.
  • Another object is to provide a tape transport including a capstan drive assembly for determining tape speed at a transducing location and for providing a particularly stable scanning relationship between the tape and the transducer head at such transducing location.
  • Another and further object of the invention is to provide a novel endless loop cartridge transducer system wherein a precision type capstan drive assembly is engagable and disengagable with the tape record medium without the necessity for manual threading of the record tape.
  • a subsidiary object of the invention is to provide such an endless loop cartridge transducer system wherein the operating tape path is free of sharp bends and yet wherein the transducer system accommodates an extremely compact cartridge configuration.
  • An important feature of the invention resides in the provision of a capstan drive assembly constructed for cooperation with a transducer head having a convex tape engaging face for optimum head-to-tape contact without the necessity for critical adjustment or excessive wear.
  • a further feature of the present invention resides in the provision of a magnetic transducer head especially suited for video signals and capable of operating with relatively high alternating current bias frequencies such as 10 megahertz or more.
  • Another feature resides in the provision of a longitudinal scanning type video transducer system capable of transducing television signals at relatively low tape speeds of the order of 30 inches per second.
  • a further feature of the invention relates to a continuous loop cartridge machine capable of transducing at least 40 channels on a quarter inch wide record tape without substantial cross talk between channels.
  • a tape transport for use in transducing any desired type of signal (including audio, instrumentation and data signals) giving exceptional steadiness of drive motion; in a cartridge of a construction whereby a capstan and multiple pressure rollers and the transducer head enter the interior during operation; and/or in a tape drive wherean isolated scanned portion of the record tape is slidably supported closely adjacent the capstan along both sides of its path between capstan drive points.
  • Further features relate to the provision of a maintenance-free drive using no belts or pulleys; and/or a capstan drive with a tape engaging face that exposes the tape to a head so that the head is freely movable between successive longitudinal channels from one edge of the tape to the other.
  • Still other objects and features relate to a cartridge adapted for coupling to a stable drive system; having no rotating parts except a tape turntable; and/or requiring no rollers or precise parts that affect the drive accuracy.
  • FIG. 1 is a partial somewhat diagrammatic plan view of a tape transport for an endless loop tape cartridge transducer system in accordance with the present invention
  • FIG. 2 is a somewhat diagrammatic plan view on a reduced scale of an endless loop cartridge for association with the tape transport of FIG. 1, with the top cover of the cartridge removed to reveal the internal construction;
  • FIG. 3 is a somewhat diagrammatic plan view on the same scale as FIG. 2 showing the tape transport of FIG. I having the cartridge of FIG. 2 associated therewith and showing the transport mechanism in the operating condition;
  • FIG. 4 is a somewhat diagrammatic top plan view of the crescent guide element of the transport of FIG. 1 and showing the crescent guide at its full size;
  • FIG. 5 is a somewhat diagrammatic front elevational view of the crescent guide element of FIG. 4;
  • FIG. 6 (on sheet 3 of the drawings) is a somewhat diagrammatic view illustrating the internal operating parts of the transport in the loading position thereof;
  • FIG. 7 is a view on the same scale as FIG. 6, but showing the relative position of the parts in the operating condition of the transport mechanism;
  • FIG. 8 (on sheet 1 of the drawings) is a fragmentary side elevational view of the tape transport of FIG. 1;
  • FIG. 9 (on sheet 1 of the drawings) is a vertical crosssectional view showing the capstan drive assembly of FIG. 8 in cross-section;
  • FIG. 10 (on sheet 1 of the drawings) is a somewhat diagrammatic perspective view showing a modified form of tape transport in accordance with the present invention
  • FIG. 11 is a partial somewhat diagrammatic side elevational view showing a head indexing mechanism suitable for the embodiment of FIG. 10;
  • FIG. 12 is a somewhat diagrammatic horizontal sectional view taken generally along the line XII--XII of FIG. 11;
  • FIG. 13 is an enlarged partial vertical sectional view taken generally along the line XIII-XIII of FIG. 11, and showing further features of preferred head indexing mechanism, which features are not present in the head indexing mechanism of FIG. 10;
  • FIG. 13A is a fragmentary vertical sectional view illustrating a bidirectionally operative detent providing a releasable coupling in the head indexing drive train;
  • FIG. 14 (on sheet of the drawings) is a somewhat diagrammatic plan view of the cartridge receiving mechanism applicable to the embodiment of FIG. 10, but with certain parts removed to show further details thereof;
  • FIG. 15 is a fragmentary somewhat diagrammatic plan view similar to that of FIG. 14 but showing parts of the mechanism in the operating position;
  • FIG. 15A is a diagrammatic illustration of an electric circuit for controlling the gradual shifting of the head from one channel to the next in response to a signal from a photocell or the like;
  • FIG. 16, (on sheet 4 of the drawings) is a somewhat diagrammatic fragmentary enlarged horizontal section view, with certain parts broken away and in section, to illustrate details of construction and illustrating a preferred capstan flywheel brake assembly specifically correlated with the cartridge receiving mechanism of FIGS. 14 and 15;
  • FIG. 17 is a somewhat diagrammatic partial vertical sectional view taken generally along the line XVII-X- VII of FIG. 16;
  • FIG. 18 (on sheet 6 of the drawings) is a somewhat diagrammatic fragmentary perspective view showing a cover for sliding engagement with the end of the cartridge of FIGS. 2 and 3, and applicable to any of the embodiments herein, for the purpose of completely enclosing the tape when not in use;
  • FIG. 19 is a somewhat diagrammatic perspective view showing a tape transport generally corresponding to that of FIGS. -17 but with a cover enclosing the operating components of the transport mechanism such as those shown in FIGS. 11-13, 14 and FIG. 20 is a partial plan view of the cover assembly of the machine of FIG. 19, looking into the cover as detached from the remainder of the mechanism and inverted to reveal its internal parts;
  • FIG. 21 is somewhat diagrammatic transverse sectional view on a different scale and taken generally along the line XXI-XXI of FIG. 20;
  • FIG. 22 is a fragmentary enlarged longitudinal sectional view taken generally along the line XXIIXXII in FIG. 20;
  • FIG. 23 is a somewhat diagrammatic enlarged fragmentary vertical sectional view illustrating details of a preferred record-play control mechanism which is preferably associated with the cover of the machine of FIG. 19;
  • FIG. 21 is a somewhat diagrammatic partial horizontal sectional view taken generally along the line XXIV-XXIV of FIG. 23 and illustrating the condition of the parts in the playback mode;
  • FIG. 25 is a view similar to FIG. 23 but showing the condition of the parts in record mode
  • FIG. 26 is a horizontal sectional view taken generally along the line of XXVI-XXVI of FIG. 25;
  • FIG. 27 is a somewhat diagrammatic plan view of the cartridge of FIG. 2, with the top cover in place;
  • FIG. 28 is a vertical sectional view of the cartridge, taken generally along the line XXVIII-XXVIII of FIG. 27;
  • FIG. 29 is a horizontal sectional view, taken generally along the line XXIX-XXIX of FIG. 28;
  • FIG. 30 is a somewhat diagrammatic enlarged bottom plan view of a tape support subassembly removed from the cartridge, and showing the tape guide arms at an extreme position beyond that permitted when the subassembly is mounted in the cartridge.
  • FIG. 1 there is illustrated a tape transport 10 for removably receiving an endless loop tape cartridge such as indicated at 11 in FIG. 2 on sheet 2 of the drawings.
  • the tape transport includes a support 12 for removably receiving the endless loop cartridge 11 and a capstan drive assembly 14 for driving the tape of the cartridge at video transducing speed during a transducing operation.
  • the support 12 carries suitable cartridge positioning elements such as lugs indicated at 15 and 16 in the FIG. 3 for engaging in cooperating recesses of the cartridge to provide for a pivotal type of movement of the cartridge on the lugs as the cartridge is loaded onto the support 12.
  • the support 12 may further include elements 19 and 20 as indicated in FIG.
  • a photocell assembly 28 on the cartridge support 12 moves through an aperture 29, FIG. 2, in the bottom of the cartridge so as to be disposed in operative relationship to the path of the tape carried by the cartridge.
  • the lugs 15 and 16 are mounted on flat pads 30 and 31 having a common level with pads 32 and 33, FIG. 1, so as to position the cartridge at a predetermined level on the support 12.
  • Spring fingers 34 and 35 project upwardly from support 12 as indicated for finger 35 in FIG. 8 and serve to retain the cartridge securely in position.
  • the lugs 15 and 16 include forwardly projecting fingers 15a and 16a which overlie a Referring to FIG. 1 transducer head 40 is mounted on the transport for shifting movement toward and away from the capstan drive assembly 14. Further, the head assembly is capable. of indexing movement parallel to the axis of the capstan drive assembly so as to scan along successive parallel channels extending lengthwise of the tape.
  • the mechanism for indexing the head 40 includes a solenoid 41 having an actuating link 42 for successively indexing ratchet wheel 43 in cooperation with tension spring 44 and pawl 45.
  • FIGS. 1 and 3 show an arm 46 pivotally mounted near its center on pin'47, the arm being located so as to carry pawl 45 at its upper end and so as to connect with link 42 and spring 44 at its lower end. Retraction of link 42 towards the left by energization of solenoid 41 pivots arm 46 towards the right so as to advance pawl 45.
  • the solenoid is deenergized the link 42 is restored by the pull of spring 44 to the position shown in FIG. 3.
  • pawl 45 is retracted while detent 48 locks ratchet wheel 43 against reverse rotation.
  • the pawl 45 is spring urged in the counterclockwise direction as is detern 48, so that the manual knob (not shown) corresponding to knob 341, FIG. 10, may rotate ratchet wheel 44 in the counterclockwise direction to manually select any desired indexing position of the head.
  • the parts associated with ratchet wheel 44 may include the parts driven by member 360, FIG. 13, so that the knob on shaft 49 in FIG. 3 may drive such parts (just as knob 418 drives parts 360 and 371 in FIG. 13) when the solenoid 41 is inactive.
  • ratchet wheel 43 may have 40 teeth corresponding to 40 successive scanning positions of the head assembly 40.
  • the indexing wheel 43 and the actuating components such as 41, 42, and 44-49 are all reciprocally movable with the head 40 toward and away from the capstan drive assembly 14.
  • capstan pressure rollers 26 and 27 are mounted by means of stationary pivot shafts 51 and 52, the rollers being carried by linkage arms 54, 55 and 56, 57 which are actuated so as to move toward the capstan drive assembly 14 along with the head 40.
  • the linkage arms are actuated by means of cam arms such as indicated at 61 in FIG. 1 and at 61 and 62 in FIGS.
  • a shiftable carrier including a slide plate indicated at 70, FIGS. 1 and 6, carries the head assembly 40 and the associated indexing mechanism and also carries actuating pins as shown at 71 and 71a in FIG. 7, for pivoting the cam arms 61 and 62.
  • the plate 70 also carries a'pin 91, FIGS. 6 and 7, for controlling a reel brake 92, FIGS. 3, 6 and 7, and carries a cam post 93 for controlling a tape drag element 94 which is pivoted at 95, and which drag element carries a felt pad 94a for pressing the tape against a fixed guide 96.
  • Reel brake 92 and drag element 94 which is pivoted at 95, and which drag element carries a felt pad 94a for pressing the tape against a fixed guide 96.
  • Reel brake 92 and drag element 94 are contained in the cartridge, through the latter could be part of the machine.
  • the photocell assembly 28 which projects into the tape cartridge carries at its lateral face 93 a photocell exciting lamp, and a receiving photocell which is actuated in response to a light reflective strip (not shown) applied to the tape when such strip reaches the tape run as indicated at 99 in FIG. 3.
  • a light reflective strip not shown
  • the tape at path section 99 does not reflect sufficient light to the photocell to actuate the photocell circuit.
  • the photocell circuit in turn controls actuation of the solenoid 41 so that the head 40 is indexed to scan a new channel each time the reflective strip reaches the photocell assembly 28.
  • the tape transport 10 carries an actuating arm as indicated at 101 which is secured for actuating a vertical shaft 102 which in turn serves to control a flywheel brake assembly 103, FIG. 8.
  • Pin 104, FIG. 3, on the shiftable carriage is so located that as soon as driving engagement between the tape and the capstan drive assembly is released, arm 101 is actuated to apply the brake 103.
  • the details of a preferred capstan flywheel brake will be described hereinafter in reference to a second embodiment of the present invention.
  • the pivot arms and 111 carried on carriage plate 70, FIGS. 6 and 7, provide guide faces 110a and 11 la for engagement with lower portions of the arms 55 and 57 (below rollers 26 and 27) as the carriage is advanced to operating position. Wire springs 112 and 113, FIG.
  • arms 61 and 62 are actuated by arms 61 and 62 as the wire springs advance with the carriage to urge arm 110 counterclockwise and arm 11] clockwise.
  • Arms 110 and 111 in turn act on arms 55 and 57 so as to establish pressure engagement between the capstan rollers 26 and 27, and the capstan drive 14.
  • the extent of pivotal movement of arms 61 and 62 is selected so as to move the linkages 54 and 55 and 56 and 57 into the proper position before the wire springs 112 and 113 become effective.
  • a microswitch actuating arm 118 which serves to actuate a microswitch controlling the energizing circuit for capstan motor 119, FIG. 9, so as to begin driving the tape past head 40.
  • the capstan motor is deenergized by virtue of a spring acting on arm 118, as the carriage plate 70 is returned to the load position shown in FIG. 1.
  • the capstan drive rollers preferably have the configuration shown in the seventh figure of my copending application'Ser. No. 60,806 for the purpose of establishing a substantial tension in the tape loop being scanned by the transducer head 40.
  • the groove in capstan roller 27 is wider than the tape and may have a depth of 0.0015 inch, so that the tape engaging diameter of roller 27 is 0.003 inch less than thatof roller 26.
  • the cartridge 11 includes a reel 120 mounted for rotation on a central bearing with minimum friction.
  • the base plate 122 of the cartridge may have an upstanding bearing post as indicated at 123, and a bearing ball 124 may be interposed between the flat upper face of the bearing post 123, and a conically shaped seat carried by hub portion 125 of reel 120, so
  • the hub 125 of the reel 120 is made as light as possible consistent with structural rigidity and includes a central annular portion and an outer hub portion joined by thin radial arms such as indicated at 126.
  • a lower radial flange 127 extends from the lower side of the hub 125 and mounts a coil 128 of record tape wound on the hub 125. The inner end of the coil 128 extends over a contoured guide surface 130 formed of a low friction material.
  • the tape engaging portion of the guide 130 is contoured so as to require a minimum distortion in the natural tape path from the inner side of coil 123 to the path between the tape drag elements 94 and 96.
  • the tape after passing between the drag elements 94 and 96 passes about guide pins carried at the free ends of arms 132 and 133 which have fixed pivot points at 95 and 135, respectively.
  • a bias spring urges the arms 132 and 133 counterclockwise and clockwise respectively so as to maintain the tape adjacent the wall portions 137 and 138 of the cartridge and thus retain the tape section 25 in a relatively taut condition.
  • the tape From the pin of pivotal guide arm 133, the tape passes about a flanged guide post 140 and past aperture 29, and then about a flanged pin on tensioning arm 143 which is pivotally mounted at 144. From pivot shaft 144, the tape returns and is wound on the outer side of coil 128.
  • a tension spring is indicated at 150 for urging a drag arm 151 in the counterclockwise direction about pivot point 95 so as to urge the movable drag element 94 toward the fixed drag element 96.
  • the spring bias on arms 132 and 133 supplies sufficient tensioning action to the tape so that the tensioning arm 143 is held so as to place its spring under substantial torsion and thus maintain the free loop under tension.
  • the reel 120 is held against ro tation by means of the reel brake 92.
  • Cam post 93 has a cam face which cooperates with a flange 152, FIG. 7, depending from arm I51, so as to release the clamp ofdrag element 94 when the cartridge is loaded onto the tape transport of FIG. 1.
  • the flange 152 on arm 151 is so arranged as to maintain the drag 94 in released condition until the head carriage reaches approximately 90 percent of its travel toward the engaged position shown in FIG. 3.
  • the arm 151 is then released so as to allow the tension spring 150 to apply drag force on the tape between elements 94 and 96.
  • the drag force exerted by elements 94 and 96 is released substantially contemporaneously with the release of driving pressure between the tape and the capstan drive assembly 14.
  • a leather brake shoe 92 is carried on an arm 153 which is pivoted on axis 154 against the action of a wire spring 155 by means of the pin 91, FIGS. 1 and 7, as the earriage is advanced to the operating position.
  • bottom wall 122 of the cartridge is provided with an aperture as generally indicated at 156, FIG. 2, so as to receive the capstan drive assembly 14 within the tape loop 25 as the cartridge is loaded onto the transport 10.
  • wire springs 112 and 113, FIG. 7 serve to urge the capstan pressure rollers 26 and 27 against the capstan so as to establish an isolated tape loop extending from an incoming side of the capstan drive to an outgoing side of the capstan drive, the drag elements 94 and 96 acting on an incoming tape path section such as indicated at 164, FIG. 3, and an outgoing tape path section such as indicated at 165 having essentially zero tension, but being sufficiently guided so as to pass in close proximity to the photocell assembly 28 which carries the lamp and photocell previously referred to.
  • the tape follows a path having a total amount of bending of substantially less than and in fact less than 45, so as to enable a relatively free movement of tape. If the tape had a relatively substantial bend at the incoming path section, this would tend to amplify any flutter which might occur along the incoming path section.
  • the tape drag elements 94 and 96 apply a relatively substantial drag force which in conjunction with the capstan drive assembly provides a tape tension at the transducer head 40 in a range from about one to four ounces for a A inch tape.
  • the space between the level of the flange 127 of reel and the bottom wall 122 is appreciably less than the width of the tape, for example l/l6 inch.
  • the reel 120 might be one half to two thirds full where the length of tape was to provide 40 channels with a capacity of 1 hour of playing time at 120 inches per second.
  • the constant friction supplied by the drag elements 94, 96 tends to swamp out any irregularities in tape motion, for example due to variations in thefriction exerted by the coil 128 as the tape is unwound from the inner side thereof, and is important in proper guiding of the tape over the pressure rolls, capstan, and head.
  • the flywheel brake operating arm 101 assumes a position adjacent its actuating pin 104 so that the brake is applied to the capstan flywheel as soon as the capstan drive is released by retraction of the capstan pressure rollers 26 and 27.
  • the tape remains somewhat loosely at the capstan when the rollers are retracted, but re-engages perfectly if the rollers are brought again to drive position.
  • the tape section 25 is brought to the taut condition shown in FIG. 2 when the cartridge is removed from the machine and the arms 132 and 133 return to the loading positions as shown in FIG. 2 under the impetus of their spring bias.
  • the machine carries actuating rollers 17] and 172, FIG. 1, which engage inclined edges of slide plates 173 and 174, FIG. 2, as the cartridge is pivoted into the operating position.
  • the rollers 171 and 172 force the slide plates 173 and 174 laterally against the action'of spring bias.
  • a suitable lost motion type linkage couples the slide plates 173 and 174 with the pivot shafts 95 and 135, causing arm 132 to rotate in the clockwise direction, and causing arm 133 to rotate in the counterclockwise direction until the arms reach the operating positions as shown in FIG. 3.
  • the arm 151 is freely rotatable relative to the pivot shaft 95, the pivotal movement of the arm 151 relative to shaft 95 having been previously explained.
  • FIGS. 8 and 9 illustrate a preferred capstan-head arrangement generally corresponding to that illustrated in the prior Camras applications Ser. No. 44,510 filed June 8, 1970, and Ser. No. 60,806 filed Aug. 4, 1970.
  • the capstan drive I assembly 14 includes a tape guide 200 providing sliding support for the tape as it travels along the loop path between the incoming and outgoing sides of the capstan.
  • the tape guide 200 is provided with a tape guide channel 201 which extends across a vertically extending recess 202.
  • the recess 202 has a generally concave configuration in cross section which is adapted to accomodate the generally convex tape engaging face 203, FIG. 1, of the head assembly 40.
  • the tape channel 201 is defined by tape engaging guide surfaces 205 and 206, having a crowned or bulging configuration (shown exaggerated), so that the tape has a slight lateral curvature in cross-section over the extent of the tape channel 201 except in the vicinity or the recess 202.
  • the tape may have a substantially flat or rectangular cross section configuration, or even have an opposite lateral curvature, if the head 40 has a crowned configuration such as illustrated in the first figure of the copending application Ser. No. 90,773 filed Nov. 18, 1970.
  • the stationary tape guide surfaces 205 and 206 are of generally arcuate configuration, conforming to the configuration of the outer edges of sections 207 and 208 of the guide 200 as illustrated in FIG. 4.
  • the tape guide surfaces 205 and 206 are of a length in the direction of movement of the record tape so as to provide sliding support for the record tape loop over substantially the entire length thereof which is out of engagement with the capstan. With the head 40 in the operating position, the tape is also provided with sliding support at the tape engaging surfaces 203 of the head.
  • the tape guide 200 further comprises a magnetic shielding member as indicated at 210 in FIG. 4 which is interposed between the capstan drive sleeve 212, FIG. 9, and the record tape loop which extends along the guide channel 201, FIG. 5.
  • the magnetic shielding member 210 may be formed of a thin sheet of magnetic material disposed in close conforming relation to the tape engaging surface 212a of the capstan sleeve 212, while being slightly spaced therefrom to accommodate free rotation of the capstan.
  • the magnetic shielding member may be made of Permalloy" having a composition of 4 percent molybdenum, 78 percent nickel. and the remainder iron and minor constituents.
  • the remainder of the tape guide 200 may be of thin electrically conductive material such as bronze with a hard chrome plating on its wearing surfaces. Crowned guide channels 201 were found advantageous in guiding the tape with a minimum of tension.
  • base 214 of the tape guide 200 may be fixedly secured to housing 215 of the capstan drive assembly 14.
  • a capstan shaft 220 has capstan sleeve 212 rigidly fixed or integral therewith and has a flywheel 221 rigidly fixed on the shaft 220.
  • the sleeve is bronze, brass or similar non-magnetic material with a surface of hard chrome.
  • the shaft 220 is preferably of hard magnetic steel. The non-magnetic capstan sleeve and surface prevents spurious pickup from the magnetic shaft by the nearby head which is very sensitive to even the slightest magnetization of a close spaced capstan.
  • a reduced diameter portion 222 of the rotor shaft is journalled in an upper bearing 223 which is supported by a rigid frame portion 224 which may be an integral part of the capstan housing 215.
  • the casing 226 of the capstan drive motor 119 is rigidly secured with the housing 215.
  • the rotor of the motor 119 is directly secured to capstan shaft 220, and the shaft is journalled by means of a bearing 227 below the rotor.
  • capstan shaft 220 may have a diameter corresponding to the outside diameter of sleeve 212 to itself provide the capstan drive surface 212a.
  • An exhaust impeller blade is indicated at 230 for rotation with the capstan shaft 220 to exhaust air from the housing 215 through apertures such as indicated at 231. Suitable air intake apertures may be provided at the lower end of the casing of motor 226 below stator 240 as viewed in FIG. 9.
  • a thrust bearing in the form of a ball 241 is shown in FIG. 9.
  • the capstan-flywheelrotor component including shaft 220, sleeve 212, flywheel 221 impeller 230 and rotor 242 is dynamically balanced such that vibration and noise is reduced to a negligible amount.
  • capstan brake 103 is reciprocally guided by means of a fixed casing 250 secured by means of screws such as indicated at 251 to the capstan housing 215.
  • a tension spring is indicated at 252 which in one embodiment in accordance with FIGS. 1-9 serve to release the capstan brake 103 upon disengagement of the pin 104 from the arm 101, FIG. 3, as the carriage plate moves to the operating position shown in FIG. 3.
  • pin 104 engages arm 102, and rotation of arm 102 drives plunger 103, FIG. 8, inwardly so that the brake shoe of the inner end of the plunger 103 engages the periphery 221a of the I flywheel 221, FIG. 9, with the desired braking pressure.
  • the parts are rearranged so that the spring serves to apply the braking pressure as the slide plate is retracted toward the loading position.
  • a pin on the carriage plate 70 serves to release the brake as the carriage plate is moved from the loading position, the flywheel brake being maintained in the disengaged condition by the pin with the parts in the operating position as shown in FIG. 3.
  • FIG. 1 is based on a photograph of an actual embodiment, the photograph having been taken at a slight angle to the vertical, so that the parts in FIG. 1 are seen in some portions with a slight degree of parallax.
  • capstan drive assembly 301 essentially corresponds to the capstan drive assembly 14, FIG. 1, and includes a capstanmotor-flywheel assembly such as illustrated in FIG. 9, and includes a tape guide in association therewith corresponding to that illustrated in FIGS. 4 and 5.
  • the embodiment of FIGS. 10-18 includes a cartridge support 302 essentially corresponding to that indicated in FIG. 1 including a photocell assembly 303, FIG. 14, corresponding to that shown at 28 in FIGS. 1 and 3. Pivotal loading of the cartridge is accommodated by elements 304-307 corresponding to elements 15, l6, l9 and in FIG. 3.
  • pads are provided at 309 and 310 adjacent the retaining lugs 304 and 305, and pads 309 and 310 are at the same level as pads 311 and 312 so as to provide level support for the cartridge.
  • Spring fingers 313 and 314 are located at the forward edges of pads 311 and 312 in a manner analogous to the placing of spring fingers 34 and 35 in FIG. 1.
  • spring fingers 313 and 314 insure the interlocking of the cartridge with the overhanging fingers 304a and 305a of lugs 304 and 305.
  • a slide plate 317 is indicated in FIG. 10 which corresponds essentially to the slide plate 70 of FIG.
  • Capstan pressure rollers such as indicated at 323 correspond essentially to the capstan pressure rollers 26 and 27 and are mounted for pivotal movement by means of linkage arms such as indicated at 324 and 325, FIGS. 14 and 15, and 326 and 327, FIG. 10, corresponding to the pivot arms 54, 55 and 56, 57 in FIG. 1.
  • the arms 324 and 326 are mounted on fixed pivots 328 and 329, carried by the support 302 clear of the path of movement of the slide plate 317.
  • a distinctive feature of the embodiment of FIGS. 10-18 resides in the use of a motor energized head indexing movement whereby the head gradually moves from one channel to the next in such a way as to prevent transients during continuous playing of successive channels.
  • the drive for the head indexing mechanism includes a drive motor 330, a reducing gear section 331, a control cam 332, spur gears 333 and 334 and worm 335 which serves to drive a worm wheel mounted coaxially with the head indexing mechanism 337.
  • an enclosure may be provided for components such as 330-335, and such enclosure may be threadedly secured to a post such as indicated at 340 at each side of the transport.
  • a manually operated knob 341 may be attached to the remaining parts of the head indexing assembly 337, so that the knob 341 may be on the upper side of the enclosure and be coupled with the remaining parts of the head indexing mechanism lying within the enclosure.
  • lndicia such as indicated at 342 may cooperate with a suitable pointer and may be suitably numbered so as to represent the channel being scanned by the head assembly. For example, one index line may have associated therewith on the surface 343 the numeral 35 indicating that when this index line is aligned with the pointer, the head assembly will be scanning channel number 35 on the record tape.
  • FIGS. 11-13 details of a preferred head indexing assembly are diagrammatically shown.
  • This head indexing assembly is similar to assembly 337 in FIG. 10 but incorporates certain additional features.
  • Spur gear 334 and worm 335 are shown in FIG. 12, and worm 335 has a reduced shaft portion 335a which is visible at the lower left in FIG. 11.
  • the worm 335 drives a worm wheel 350, FIG. 13.
  • the worm wheel 350 is provided with a hub portion 351 secured by set screw 353 to a vertical shaft 352.
  • a set screw 354 secures a ratchet tooth member 355 to shaft 352 so that worm wheel 350 drives ratchet tooth member 355 having an annular series of ratchet teeth along an upper edge thereof as indicated at 356.
  • a ratchet follower sleeve 360 fits over shaft 352 and includes a ratchet finger 361 for cooperating with the series of ratchet teeth 356. Specifically, rotation of the ratchet member 355 by means of the worm wheel 350 is effective to drive the member 360 therewith by virtue of the coupling between the ratchet finger 361 and the ratchet teeth 356.
  • a knob 418 generally similar to knob 341, FIG. 10, is telescoped over a sleeve 370 of a cam member 371, so that the cam member 371 may be directly rotated by means of the manual knob 418 without rotation of the worm 335.
  • the knob 418 As the knob 418 is rotated, the ratchet finger 361 rides over the successive ratchet teeth 356, the ratchet member 355 thus remaining stationary. On the other hand, as the worm 335 is driven, the cam member 371 and the indicator knob 418 are both rotated therewith.
  • the head indicated at 380, FIG. 12 may be advanced automatically to successive channels by means of the motor drive, or the head may be set at any desired channel by manual operation of the knob 418.
  • the head 380 is carried by means of a bracket 381 which is guided for vertical reciprocation by means of a guide rod 383, and a guide groove as indicated at 384.
  • the head slide 387 includes an aperture slidably receiving guide rod 383 and includes a beveled edge 387a confined by the guide groove 384.
  • the head slide 387 carries a cam follower 390 which rides on the cam edge face 371a of cam member 371.
  • the head slide 387 is shown in an intermediate position in FIG. 11 and is urged upwardly by means of the hairpin spring 393. As cam member 371 is rotated, cam follower 390 follows along the cam edge 371a to progressively depress the head 380 against the action of the spring 393.
  • a bracket 395 serves to fasten casing 396 of the head indexing mechanism to slide plate 317 as shown in FIGS. 14 and 15.
  • FIG. 12 shows a sectional view along lines XII- -XII of FIG. 11, but with cam member 371 removed from sleeve 360 to show underlying parts with greater clarity.
  • the cam 371 is shown about one-quarter of a revolution beyond the position where the head is in scanning relation to the upper channel (channel No. l) on the tape.
  • the head still has at least about 3/16 inch of downward travel from the position shown in FIG. 11 before it reaches its lowest position, where the tape width is 54 inch.
  • slide 387 is shown approximately midway along the verticaI-extent of guide rod 383 in FIG. 11, nevertheless the dimensions shown in FIG. 11 are such that slide 387 can still move downwardly the required distance of almost A inch.
  • FIG. 13A shows a modification of the head indexing drive train of FIG. 13 wherein member 355' which is secured to shaft 352 as indicated for member 355 in FIG. 13, drives a follower sleeve 360' corresponding to ratchet follower sleeve 360 in FIG. 13.
  • sleeve 360 carries a spring urged detent ball 400 which coacts with symmetrical detent teeth 356.
  • the spring urged detent ball 400 acts against teeth 356' with sufficient force to insure that worm 350 will drive cam member 371 in the same way as for the embodiment of FIG. 13.
  • Knob 418 may be turned in either direction when the bidirectional detent of FIG. 13a is substituted for parts 355, 356, 360 and 361 in FIG. 13.
  • FIGS. 16 and 17 illustrate details of a capstan flywheel brake similar to that indicated at 103, FIG. 8, and described in reference to the previous embodiment.
  • capstan motor 322 has a flywheel 401, FIG. 16, thereon corresponding to the flywheel 221 shown in FIG. 9.
  • the flywheel housing 402 has a casing 403 secured therewith corresponding to casing 250, FIG. 8.
  • the casing 403 includes an interior wall 403a for reciprocally mounting a plunger 404 carrying brake shoe 405.
  • casing 403 is provided with a pivot shaft 406 pivotally mounting a lever 407.
  • the lever 407 has secured therewith a circular disk 408 which is rotatably journaled in a circular receiving ap erture of casing 403.
  • the lever 407 is fixedly secured with pivot disk 408 by means of a screw as indicated at 410.
  • Plunger 404 is provided with an elongated aperture 404a receiving the pivot shaft 406 therethrough so as to accommodate reciprocal movement of the plunger 404 toward and away from the flywheel 401.
  • the lever 407 is coupled with plunger 404 by means of a slot 408a disposed radially in the circular member 408 and a pin 412 fixedly secured to plunger 404.
  • a tension spring is diagrammatically indicated at 414 which acts on the free end of lever 407 so as to tend to rotate the lever in the clockwise direction about shaft 406 as viewed in FIG. 16, so as to tend to establish pressure braking relation between brake shoe 405, which may be of leather, and the periphery 401a of flywheel 401.
  • an actuating cam 415 is provided in engagement with side edge 407a of lever 407, cam 415 being rotatable with its shaft 416 in a clockwise direction to rotate lever 407 in a counterclockwise direction about shaft 406 in retracting plunger 404 and brake shoe 405 away from the periphery 4010 of flywheel 401.
  • tension spring 414 serves to apply the brake to the flywheel.
  • actuating shaft 416 is shown as extending through support 302 and carrying an actuating finger 420 disposed for engagement with an edge 3171) of slide plate 317 as the slide plate is moved from the loading position shown in FIG. 14 to the operating position shown in FIG. 15.
  • This movement serves to rock shaft 416 in the clockwise direction through a sufficient angle to release the application of brake 405 at the same time that microswitch arm 321 is operated to start the capstan motor 322.
  • slide plate 317 is retracted from the operating position shown in FIG.
  • microswitch arm 321 is released to deenergize the capstan motor, and finger 420 returns to its position in registration with notch 3170 so as to allow tension spring 414 to drive shaft 416 in the counterclockwise direction while at the same time driving lever 407 in the clockwise direction to apply brake 405 to the periphery 401a of flywheel 401.
  • the capstan of the capstan drive assembly 301 is rapidly brought to a stop as the slide plate 317 is retracted to the loading position.
  • FIGS. 11-13 may be considered as applied to the head indexing mechanism 337 of FIG. 10 as well as to the head indexing mechanism of FIG. 13 which specifically incorporates a fine adjustment feature.
  • actuating knob 341 of FIG. 10 is replaced by a knob assembly 417 including a main adjustment knob 418 whose operation corresponds exactly to the operation of knob 341 in FIG. 10.
  • the knob assembly 417 further includes a fine adjustment knob part 419 which in the embodiment of FIG. 13 is rotatable relative to the main knob part 418.
  • knob parts 418 and 419 were fixedly secured together, the embodiment of FIG. 13 would correspond essentially to the head indexing mechanism 337 of FIG. 10. That is, knob parts 418 and 419 could be replaced by the knob 341 in FIG. 13, and the disclosure of FIGS. 11-13 would then be applicable to the head indexing mechanism 337 shown in FIG. 10.
  • end bearing washer 420 is fixedly secured to the end of shaft 352 by means of screw 421 and serves to prevent axial displacement of fine adjustment knob 419 relative to shaft 352, while accommodating rotation of the fine adjustment knob 419 on the central vertical axis of the indexing mechanism.
  • the fine adjustment knob 419 is provided with a cam follower protrusion 419a which is in engagement with a circular cam face 370a of sleeve 370.
  • the slope of the cam face 370a is such that one revolution of knob 419 will shift sleeve 370 axially a distance of 0.0062 inch corresponding to the center to center spacing between adjacent tracks on the record medium being scanned by head 380.
  • a compression spring is indicated at 422 for accommodating shifting of sleeve 370 and cam part 371 relative to the adjustment knob 419 in the axial or vertical direction.
  • the sleeve 370 is provided with an internal keyway 370b which is in alignment with a keyway 360a of ratchet follower sleeve 360.
  • a key is shown at 423 for locking members 360 and 370 for joint rotation while accommodating the required slight axial movement of member 370 and main knob 418 relative to member 360.
  • Main knob 418 is secured with the cam sleeve 370 by means of set screw 424.
  • the position of the fine adjustment knob 419 in FIG. 13 may represent approximately a mid point in its range of adjustment.
  • the follower 419a will travel along an upwardly sloping part of cam face 370a, forcing sleeve 370 and knob 418 downwardly against the action of compression spring 422.
  • edge face 371a of cam 371 will, of course, act on the follower 390, FIGS. 11 and 12, moving the head slide 387 downwardly against the action of wire spring 393.
  • main knob 418 can only be rotated in the clockwise direction permitted by the ratchet finger 361.
  • the ratcheting action of finger 361 relative to teeth 356 provides a manual feel" which enables the accurate manual indexing of the head to successive channels on the tape once the fine adjustment knob 419 has been accurately adjusted for a given tape. In any given position to which the knob 418 is rotated, a slight attempt to rotate knob 418 in the counterclockwise direction will insure that ratchet finger 361 is tightly engaged with the correct ratchet tooth 356 so as to establish the precise indexing position during manual channel selection.
  • the deenergized positions of the motor 330 are accurately determined by the notch 3320, FIG. 15A, of cam 332.
  • the maximum variation in stopping position of the cam 332 is less than the angular extent of notch 332a. Since notch 332a may have an extent equal to about 36, for example, or about 10 percent of the channel to channel separation, the possible variation may be less than 0.0006 inch or less than 10 percent of the adjustment range provided by fine ad- 5 justment knob 419. Further in actual operation the stopping position of the motor 330 is consistent to within a degree or so, and as noted even the worst case of possible variation corresponds to less than 0.6 mil, a variation which would not be noticeable in the picture produced by the head.
  • Preferably fine adjustment knob 419 has an established neutral position to which it is set for recording operation such as the mid position in its range of adjustment.
  • a detent is shown in FIG. 13 for acting between knobs 418 and 419 to establish the desired neutral position. More specifically adjustment knob 419 is shown as having a spring urged detent ball 425, and knob 418 is shown as having a ball receiving depression 426 which serves to provide a manually discernible neutral position of knob 419 relative to knob 418.
  • FIGS. 14 and 15 The manner in which the pressure rollers such as 323 are actuated between the retracted position as shown in FIG. 14 and the operating position as shown in FIG. 15 can be understood from FIGS. 14 and 15, particularly when considered in conjunction with FIGS. 6 and 7 showing the previous embodiment which is essentially similar.
  • the last two digits of the reference numerals applied to the actuating components for the pressure rollers in FIGS. 14 and 15 will correspond to the digits of the reference numerals designating such parts in FIGS. 6 and 7.
  • cam arms 461 and 462 are actuated by means of pins such as indicated at 471a carried by the shiftable plate 317 in a manner which is analogous to the operation of components 61, 62, 71 and 71a in FIGS. 6 and 7. Pivot points for the cam arms 461 and 462 are shown at 463 and 464 in FIG. 15. Further, a bracket is diagrammatically indicated at 467 in FIGS. 14 and 15 fixedly secured to linkage arm 324 and corresponding to bracket 67 in FIGS. 6 and 7. As diagrammatically indicated in FIGS. 14 and 15, cam arm 461 carries a roller 465 at the free end thereof, which roller corresponds to roller 65 in FIGS.
  • FIGS. 14 and 15 linkage arms 326 and 327 and the pressure roller carried by arm 327 have been omitted so as to show the cooperation between arm 462 and other parts of the mechanism.
  • pivot arms 510 and 511 are shown in FIGS.
  • pivot arms 14 and 15 pivotally mounted on the slide plate 317 by means of pins 508 and 509, these pivot arms corresponding to pivot arms and 111 in FIGS. 6 and 7.
  • the pivot arms are provided with guide faces 510a and 511a for engagement with portions of the linkage arms 325 and 327 located below the respective pressure rollers such as 323.
  • Wire springs 512 and 513 correspond to wire springs 112 and 113 in FIGS. 6 and 7, and are arranged so as to be actuated by the arms 461 and 462 at portions thereofjust below the respective rollers 465 and 466 as specifically shown for the arm 462 and spring 513 in FIG. 15.
  • pins such as 471a coact with cam surfaces such as 462a of cam arm 462 to pivot the cam arm 462 counterclockwise on its pivot 464.
  • This moves the associated linkage arm 326 in a clockwise direction about its pivot 329, FIG. 10, in a manner analogous to the movement of linkage arm 324 in the counterclockwise direction about its pivot 328.
  • the linkage arms 324 and 326 are moved in the counterclockwise and clockwise directions respectively about their pivots 328 and 329, the portions of arms 325 and 327 coaxial with the pressure rollers ride on the guide faces 510a and 511a, FIG.
  • pins such as 471a are retracted so as to ride along the cam surfaces such as indicated at 462a, FIG. 14, the wire springs 512 and 513 tending to urge the cam arms 461 and 462 in the counterclockwise and clockwise directions respectively as permitted by the pins such .as 471a.
  • the cam arms 461 and 462 are also urged toward their initial positions shown in FIG. 14 because of torsion coil springs (not shown) acting on the linkage arms 324 and 326.
  • the torsion spring acting on arm 324 has one end secured to base 602 adjacent pivot shaft 328 and the other end attached to arm 324, the spring being loaded so that it urges arm 324 to rotate in a clockwise direction about pivot 328.
  • the other torsion spring associated with arm 326 is similarly arranged and is loaded so as to urge arm 326 to rotate in a counterclockwise direction.
  • wire springs 516 and 517 are mounted on slide plate 70 so as to engage arms 54 and 56 as the slide plate is retracted from the operating position shown in FIG. 7, so as to rotate arms 54 and 56 from the position shown in FIG. 7 to the position shown in FIG. 6.
  • the springs 516 and 517 are thus an alternative to the torsion coil springs actually used in FIGS. 10-17.
  • Wire springs such as that indicated at 521, FIGS. 14 and 15, act on linkage-arms 324-327 in such a way that the linkage arms 324-327 assume the collapsed configurations such as shown in FIG. 14 as slide plate 317 is retracted to the loading position.
  • These wire springs such as 521 also insure that the pressure rollers such as 323 will be properly guided by'means ofthe guide faces such as 510a as the slide is moved to the operating position. Similar wire springs are shown at 518 and 519 in FIGS. 1 and 3.
  • linkage arms 324 and 326 may be provided with flange strips such as indicated at 525. (Arms 324 and 326 are shown in FIG. 10 without flange strips, as in an earlier version of the present embodiment.) These flange strips serve to overlie the front edge of the cartridge in the operating position of the mechanism as shown in FIG. 15 so as to prevent any attempt to remove the cartridge prior to returning'the mechanism to the load condition shown in FIG. '14.
  • FIG. 18 shows the cartridge for the embodiment of FIGS. 10-17, the cartridge being designated by the reference numeral 11 since it is identical to the cartridge of FIG. 2.
  • the cartridge is provided with an aperture 29 for receiving the photocell 28 and an aperture 156 therein which serves to receive capstan drive assembly 301, as the cartridge is pivoted downwardly into the operating position after engagement with lugs 304 and 305, FIG. 14.
  • the aperture 156 is further of a size to receive the capstan pressure rollers such as 323 which are advanced as indicated in FIG. 15 into the aperture 156 as slide 317 moves to the operating position.
  • the strips such as indicated at 525 carried on the linkage arms 324 and 327 overlie regions such as indicated at 530 and 531 of cartridge 11 to prevent any attempt at removing the cartridge 11 from the machine so long as the machine remains in the operating position as shown in FIG. 15.
  • the strips such as 525 are pivoted about the pivot axes 328 and 329 respectively to positions such as shown in FIG. 14 where the strips are entirely clear of the cartridge 11 and of the tape path indicated at 25 at the front of the cartridge.
  • a suitable cover such as indicated at 532 in FIG. 18 may be slipped over the front end of the cartridge so as to completely cover any apertures therein such as 29 and 156, FIG. 2, and thus render the cartridge dust proof and fully protect the tape at path section 25 of the cartridge.
  • the interior walls forming the left and right sides and top and bottom of the open space within the cover 532 may engage the corresponding faces of cartridge 11 such that the cover 532 is frictionally retained in assembly with the cartridge 11 against any inadvertent separation, but the frictional retaining forces being such that the cover 532 can be readily manually removed from the end of the cartridge 11 when it is desired to mount the cartridge in the machine.
  • the open end 533 of cover 532 provides an opening with a cross-section so as to relatively freely accommodate insertion of the end of cartridge 11.
  • the edges of the cartridge such as indicated at 534 and 535 may be sufficiently rounded so as to facilitate insertion of the end of the cartridge into the opening 533.
  • the top and bottom and sidewalls of cover 532 and end wall 536 are completely solid and free of apertures therethrough so as to provide an effective dust cover for the cartridge 11, which encloses and seals apertures 29 and 156, FIG. 2.
  • the top and bottom edges of the cartridge 11 may also be sufficiently rounded so as to facilitate insertion of the cartridge into the open end 533 of the cover 532.
  • FIGS. 1-18 Except as specifically mentioned herein, the structure and operation of the embodiment of FIGS. l-9 corresponds to the structure and operation of the embodiment of FIGS. 10-18.
  • the descriptionandiillustration of each embodiment is specifically applied with respect to the other embodiment except where differences are specifically noted or illustrated in the drawings.
  • the following summary of operation will encompass both embodiments since the detailed showings of various features of the respective embodiments complement each other in providing a complete understanding of both.
  • the cartridge for both embodiments is illustrated in FIG. 2 and is so constructed that when removed from the transducer mechanism, a brake as indicated at 92 is applied to reel 120. Further, arms 132 and 133 are spring urged to the positions shown in FIG. 2 so as to define a straight tape path at 25 facilitating loading of the cartridge with the transport mechanism.
  • a tape tension arm 143 is provided along the tape path for applying tension to the tape as the cartridge is unloaded from the transport mechanism. The tensioning arm 143 is urged in a clockwise direction about pivot point 144 by means of a wire spring as indicated at 540 so as to maintain the tape at path section 25 in a taut straight line condition.
  • the tape path section 25, FIG. 2 moves between the capstan assembly 301 and the capstan pressure rollers such as indicated at 323, FIG. 14.
  • the transducer head for the embodiment of FIGS. -18 is indicated at 380 in FIG. 12, and is disposed generally as indicated for head 40 in FIG. 1 in the loading condition of the transport mechanism.
  • carriage 317, FIG. 14, together with the head indexing assembly 337 and the head 380 are actuated to an operating position as represented in FIG. 15.
  • the head 380 has its convex face as indicated at 380a, FIG. 12, inserted into a vertical groove as indicated at 202 in FIG. 5 of the tape guide 200.
  • a detailed showing of the relationship between the pole pieces of the transducer head and the tape which extends along the channel 201 of tape guide 200, FIG. 5, is found in the second figure of the copending application Ser. No. 60,806, and is applicable with respect to each of the embodiments of the present diclosure.
  • capstan pressure rollers such as 323 are advanced so as to establish an operating loop path for the tape, with the tape pressed into driving engagement with the capstan at the periphery thereof such as indicated at 212 in FIGS. 1 and 8 at each of the opposite sides of the capstan.
  • a tape drag such as provided by components 94 and 96 in FIG. 3 acts at the incoming tape path.
  • the tape drag is operable to apply a drag force to the tape which exceeds the momentum force on the tape at the outgoing tape path due to the inertia of reel and the associated parts.
  • the tape drag elements such as 94 and 96 in each embodiment apply a relatively substantial drag force which in conjunction with the capstan drive assembly provides a tape tension at the transducer head in a range from about 1 ounce to about 4 ounces for a 4 inch wide magnetic tape.
  • the incoming tape path such as indicated at 164 from the inner side of coil 128 to the incoming side of the capstan drive assembly follows a path having a total amount of bending of substantially less than 90, and in fact less than 45, so as to enable a relatively free movement of the tape.
  • the constant friction supplied by the drag elements 94, 96 tends to swamp out any irregularities in tape motion, for example, due to variations in the friction exerted by the coil 128 as the tape is unwound from the inner side thereof, and is found to be important in facilitating proper guiding of the tape over the pressure rolls, the capstan and the head during operation of the system.
  • the capstan drive rollers in each embodiment preferably have the configuration shown in the seventh figure of said copending application Ser. No. 60,806 for the purpose of establishing a substantial tension in the tape loop being scanned by the transducer head.
  • the groove in the capstan roller at the incoming side of the tape loop is wider than the tape and may have a depth of about 0.0015 inch, so that the tape engaging diameter of this capstan roller is about 0.003 inch less than that of the capstan roller at the outgoing side of the tape loop.
  • the outgoing tape path section such as indicated at 165 in FIG. 3 has essentially zero tension but is sufficiently guided so as to pass in close proximity to the photocell assembly 28 or 303 which controls the successive vertical indexing movement of the transducer head.
  • solenoid 41 is momentarily energized to index the ratchet wheel 43 through one increment of its movement, so as to shift the head 40 from the scanning of one channel longitudinally of the tape to the scanning of the next adjacent longitudinal channel.
  • each actuation of the photocell assembly 303 serves to close an energizing circuit for motor 330.
  • the motor rotates a drive train including worm 335 which in turn progressively moves the head 330 in a vertical direction by rotation of the cam 371, FIG. 11, having the cam face 3710.
  • This motor energizing circuit is under the control of a switch operated by cam 332 which is included in the drive train, so that the motor 330 is deenergized at a precisely determined position of the head 380 corresponding to the next channel on the tape.
  • the cam 332 is provided with a notch controlling opening of this electric switch, and the notch has a sufficient angular extent, for example 30, so that the drive train will come to a stop while the cam actuating the switch is still in registry with the notch of the cam wheel 332, thus preventing the inherent momentum of the drive train from reclosing the switch and reenergizing the motor 330 when it is necessary that the motor come to a stop with head at the next channel to be scanned.
  • the speed of the motor 330 and the reduction ratio of the drive train to the head is such that the vertical indexing movement of the head between successive channels takes place over an interval corresponding to a substantial distance of travel of the tape, the gradual transition between successive channels as scanned by the magnetic head being illustrated in the ninth figure f U.S.
  • FIG. A An exemplary electric circuit is shown in FIG. A wherein the photocell circuit 303 may include a suitable monostable drive for electronic switch 542 such that each actuation of the photocell 303 maintains switch 542 conductive for a sufficient time interval to insure that motor 330 has driven cam 332 a sufficient angular distance so as to close contacts 543 and 544.
  • the electronic switch 542 may also be a monostable circuit with an on time such that the switch 542 will be non-conducting before notch 332a of cam 332 again comes into registry with follower 543a. Then, as soon as notch 332a again registers with follower 5430, the energizing circuit for motor 330 is opened and the drive train is brought to a stop in a position of the cam 332 such as indicated in FIG. 15A.
  • the reflecting element on the tape that actuates photocell 23 or 303 may be 1 4 inches long in the direction of tape travel, giving a trigger pulse from photocell 303, FIG. 15A, lasting about 0.01 second, when the tpe travels 120 inches per second.
  • the electronic switch 542 may be a monostable multivibrator circuit which is actuated to the conductive state by the trigger pulse from photocell 303, and which remains conducting at least until notch 322a is out of register with follower 543a and switch contacts 543, 544 are closed.
  • the switch 542 once triggered, may remain closed a time interval corresponding to at least 30 of rotation of cam 332 or at least about 0.042 second.
  • the electronic switch 542 must open in less than 0.5 second in this example so that the motor 330 will be deenergized when cam 332 has made a complete revolution.
  • the tape speed For a tape speed of 120 inches per second, the tape travels 60 inches during a channel changing interval of 0.5 second, giving a vey gradual and unnoticeable transition. If a faster change is desired, the cam speed may be increased and the associated elements adjusted accordingly.
  • the electronic switch 542 is adjusted to provide a correspondingly longer on time to compensate for the lag and insure reliable cycling of the motor 330.
  • Each of the illustrated embodiments is capable of operation at speeds of 120 inches per second, or more, and with scanning of a total of 40 channels on a 5 inch wide tape without substantial cross talk.
  • the loop path extending from the incoming side of the capstan to the opposie outgoing side of the capstan has a length less than the capstan circumference, the transducer head being arranged for scanning cooperation with the record tape in such a way that the tape path conforms with the convex contour of he head as indicated at 380a, FIG. 12, but with an air space between the non-magnetizable backing of the tape and the bottom of the groove 202 such that the transducer head engages the record tape at an unbacked portion of the loop path.
  • a soft spongy pad may be secured in groove 202 and, for example, occupy the entire volume of the groove, so that the tape is resiliently backed in each scanning position of the head, the pad having a cover of smooth low friction material to facilitate smooth indexing movement of the head relative thereto.
  • the tape guide channel may have a convex contour over an extent of the tape guide surface corresponding to a major portion of the loop path of the magnetic tape from the incoming side of the capstan to the outgoing side of the capstan.
  • a microswitch finger 321 is released to deenergize the capstan drive motor, and operating finger 420 is released allowing spring 414, FIG. 16, to cause the application of the brake 405 to flywheel 401, and the reel brake as indicated at 92 in FIGS. 2 and 3 is released to allow spring 155, FIGS. 6 and 7, to exert a braking force on the reel.
  • the drag provided by elements such as 94 and 96 is released as the carriage 317 is retracted to the loading position so that movememt of the tape is brought to a stop by means of the reel brake 92 at the same time that the capstan is being stopped by means of capstan brake 405, FIG. 16.
  • the tape drag is substantially released approximately simultaneously with the release of driving engagement be tween the capstan and the tape.
  • the drag force on the tape is released generally contemporaneously with the release of engagement between the capstan and the pressure rollers.
  • the capstan flywheel brake is operable to essentially stop the capstan during the minimum time required to remove and replace a cartridge relative to the support, so that there would be no possibility of the capstan continuing to rotate at the time a new tape is engaged therewith.
  • the capstan brake operates with sufficient speed so that the capstan will stop rotating in approximately the time required for the reel brake 92 to stop the movement of the magnetic tape, so that tape of the cartridge can be re-engaged with the capstan at any substantial time subsequent to the actuation of the transport mechanism to the loading position after a playing operation.
  • a cover 532 may be applied over the open end of the cartridge 11 as shown in FIg. 18 so as to provide a dust proof enclosure for the magnetic tape when the cartridge is not in use.
  • FIGS. 19-26 there are illustrated further features which may be applied to any of the preceding embodiments for the purpose of facilitating manual shifting of the carriage or 317 from the load to the operating position, for the purpose of automatically returning the carriage to the load position after completion of scanning of all of the channels of a tape, where desired, and for the provision of other advantageous

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US00282275A 1972-06-01 1972-08-21 Video transducer system and cartridge therefor Expired - Lifetime US3849797A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US00282275A US3849797A (en) 1972-08-21 1972-08-21 Video transducer system and cartridge therefor
US05/346,869 US4020999A (en) 1972-06-01 1973-04-02 Endless loop cartridge for video
DE19732331164 DE2331164C3 (de) 1972-08-21 1973-06-19 Kassettengerät für Aufnahme und Wiedergabe von höherfrequenten elektrischen Signalen, insbesondere Fernsehsignalen
CA174,665A CA1033058A (en) 1972-08-21 1973-06-21 Video transducer system and cartridge therefor
JP48093783A JPS5821341B2 (ja) 1972-08-21 1973-08-21 エンドレス ル−プ カ−トリツジヘンカンソウチ
NL7311500A NL7311500A (cs) 1972-08-21 1973-08-21
US05/533,485 US4032985A (en) 1972-08-21 1974-12-17 Video transducer system and method with tape drag between the reel and the capstan

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US00282275A US3849797A (en) 1972-08-21 1972-08-21 Video transducer system and cartridge therefor

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US05/346,869 Continuation-In-Part US4020999A (en) 1972-06-01 1973-04-02 Endless loop cartridge for video

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US3849797A true US3849797A (en) 1974-11-19

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4998833A (en) * 1990-01-17 1991-03-12 Hwang Chiman Refillable ink ribbon cartridge for use in an electronic typewriter

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US2745604A (en) * 1951-05-11 1956-05-15 Rca Corp Tape tension winding control
US3154308A (en) * 1960-04-28 1964-10-27 Vm Corp Multi-track magazine tape recorder with movable head and elastic band drive for tape and reels
US3265817A (en) * 1962-01-12 1966-08-09 United Data Control Inc Magnetic tape cartridge
US3269671A (en) * 1963-10-15 1966-08-30 Torque Ind Inc Tape cartridge with regulated tension
US3341143A (en) * 1964-08-05 1967-09-12 Telex Corp Tape cartridge
US3370131A (en) * 1963-12-31 1968-02-20 Television Res Ltd Multi-track magnetic head moving apparatus
US3388911A (en) * 1966-06-22 1968-06-18 Muntz Stereo Pak Inc Head shift mechanism for tape recorder and playback machines
US3580525A (en) * 1967-11-21 1971-05-25 Telefunken Patent Arrangement maintaining constant tape tension in magnetic tape recorders

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4212506Y1 (cs) * 1964-06-17 1967-07-14

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2745604A (en) * 1951-05-11 1956-05-15 Rca Corp Tape tension winding control
US3154308A (en) * 1960-04-28 1964-10-27 Vm Corp Multi-track magazine tape recorder with movable head and elastic band drive for tape and reels
US3265817A (en) * 1962-01-12 1966-08-09 United Data Control Inc Magnetic tape cartridge
US3269671A (en) * 1963-10-15 1966-08-30 Torque Ind Inc Tape cartridge with regulated tension
US3370131A (en) * 1963-12-31 1968-02-20 Television Res Ltd Multi-track magnetic head moving apparatus
US3341143A (en) * 1964-08-05 1967-09-12 Telex Corp Tape cartridge
US3388911A (en) * 1966-06-22 1968-06-18 Muntz Stereo Pak Inc Head shift mechanism for tape recorder and playback machines
US3580525A (en) * 1967-11-21 1971-05-25 Telefunken Patent Arrangement maintaining constant tape tension in magnetic tape recorders

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US4998833A (en) * 1990-01-17 1991-03-12 Hwang Chiman Refillable ink ribbon cartridge for use in an electronic typewriter

Also Published As

Publication number Publication date
DE2331164A1 (de) 1974-03-21
CA1033058A (en) 1978-06-13
JPS5821341B2 (ja) 1983-04-28
DE2331164B2 (de) 1976-11-11
JPS4965807A (cs) 1974-06-26
NL7311500A (cs) 1974-02-25

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