DE7713667U1 - MAGNETIC TAPE TRANSPORT - Google Patents

Description

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j S magnetic tape transport ^? {

The invention relates to a magnetic tape transport with automatic
Threading of a magnetic tape with threading leader tape, essentially consisting of a frame, an unwinding reel in a
Cassette and a take-up roll, at least one circular,
rotating capstan for simultaneous
Both rollers are driven by contact pressure on the respective roller circumference, as well as a detachment device for the threading leader tape, the tape drive roller and the rollers being rotatable
Shafts mounted and the shafts of the rollers on carriers opposite
the stationary shaft of the tape drive roller arranged movably
are, so that a change in distance / takes place between the tape drive roller and the rollers during the tape transport, and be j

standing from devices for generating compressive forces on |

the contact points between the capstan and the rollers |

and a band tension in the band section between the contact §

and where the cassette consists of two halves and |

an opening device for the cassette is provided. |

Controlling the loading and threading processes requires a lot of effort dige mechanical, electromagnetic and electronic control J facilities. «

In addition, the devices for generating the tape tension I are complex additional electromagnetic components, usually | trained as motors. j

Only in one of the embodiments, a spindle is provided with a \ moving it bracket, said spindle by means of a
Rotational direction reversible motor is rotatable. This temple has that

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Purpose through targeted blocking and releasing of the carriage carriers the threading in and out processes as well as the belt tensioning process accomplish. The control takes place via separate complex Control devices.

This is done with the other known magnetic tape transports Insertion of the supply tape roll, threading of the threading leader and tensioning of the tape with various types of Resources. It has been found, however, that those used to control the loading, threading and tensioning operations complex mechanical and electronic components are very problematic in terms of reliability and cost, so that it can be put to practical use in an economical recording / reproducing system is excluded.

It is the object of the invention to provide a magnetic tape transport of the type described in more detail at the beginning, which is the known Transport units improved and the use of simple and reliable components made possible.

The invention solves the problem in that the opening device consists of at least one movably mounted, in its rest position by means of a spring device in the opening direction of the cassette prestressed opening element, which engages on a cassette half, and that the carrier of the unwinding reel in the loading position of the cassette holds the opening element in its rest position and by moving the carrier the opening element can be released in the direction of the capstan, whereby the cassette is opened by means of the spring device.

Further embodiments of the device according to the invention can be seen from the claims for protection.

The tape drive member is hereinafter referred to as "Kapstan" as usual. designated.

The present invention is generally a simple and relatively cheap cassette loading and tape tensioning system for Use on a drive where the supply roll is unwound from a hub attached to a rotatable, on a Slide arranged shaft is attached. The slide can either move in a straight line or in the manner of a swivel arm, whereby the roll of tape is urged against a capstan which drives the roll by contact with the outermost turn of the tape. It allows the hub to move to the capstan every now and then if the diameter changes during operation the unwind roll decreased or increased,

In the case of the tape transport device used according to the invention or In addition to the tape drive, the supply roll is attached to a hinged, normally closed tape cassette condition. The cassette is inserted into the receiving device and the unwinding hub on one on the winding hub arranged shaft attached. Now a locking device that holds the two halves of the cassette together is released and the The cassette can be opened by pivot arms which grip the front part of each cassette half, so that the supply reel can be pressed against the capstan.

As soon as the cassette is opened and the supply reel is pressed against the capstan, the tape is wrapped around the capstan and onto the take-up reel threaded, with the help of a tape threading device. After the threading process, the unwinding roll is removed from the Close contact with the capstan is reduced slightly to prevent ribbon loops to eliminate. Once this is done, the supply reel is returned to its operative position, i. pressed against the capstan.

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According to the invention, all of the cited Schratte are made solely with the aid controlled by the only motor-driven lead screw system that is very simply mechanically coupled to the slide, The The spindle controls the sequence and timing of all steps in the tape loading and tensioning system and is available with a simple logic circuit in connection, which is also used for other punctures of the transport device.

Details of the invention can be found in the following description and drawing of an exemplary embodiment.

Show it

Figure 1 is a perspective view of a cassette insertion and tape tensioning system according to an embodiment of the present invention;

Figure 2A is a plan view of the device shown in Figure 1;

FIG. 2B is a plan view similar to that of FIG. 2A, but in which several elements are shown in a different position.

FIG. 3A is an enlarged partial plan view of that shown in FIG. 2A Contraption;

FIG. 3B is an enlarged partial plan view similar to that of FIG 3A, in which, however, several elements assume the position shown in FIG. 2B;

FIG. ¹ JA shows a section along the line A - A in FIG. 3A;

Figure 4b shows a section similar to that of Figure ¹ IA, but taken along line B - B in Figure 3B;

FIG. 5 is a block diagram in which the sequence of the insertion and tensioning processes is contained;

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I Figure 6 is a block diagram in the order in which the |

the nature of the unwinding roll is shown. I.

Figure 1 shows schematically an embodiment of a cassette

insertion and strap tensioning system. The system is in connection with _Ä

a tape drive having a capstan 10, |

at the same time the unwinding roller 20 and the winding roller 30 |

by contact with the outermost turn of the magnetic tape 40 on |

each role drives. ■

Reference is also made below to FIGS. 2A and 2B. The unwinding roll 20 comprises a hub 21 which is fastened to a shaft 21 arranged on a swivel arm slide 23. Correspondingly, the take-up roll 30 has a hub 31j which is mounted on a shaft 32 arranged on the swivel arm slide 33. Carriages 23 and 33 push unwind and take-up rollers 20 and 30 towards each other against capstan 10 under the action of a constant tension spring 11 connecting the carriages at points 24 and 34. As the diameter of the tape reel each changes Roll, as a result of the tape transport past the recording / playback head 15, the carriages rotate about the pivot points 25 and 35j so that the roller hubs move independently of one another towards or away from the capstan _; can move.

The first step in the loading process is that the Hinged so-called clamshell or folding cassette 41, which contains the unwinding tape roll 42 on hub 21 in the cassette receiving device 60 is inserted. The receiving device 60 has a hinged hinged door 61 (with dashed and dotted lines), which is arranged so that the hub 21 is pressed onto the unwinding shaft 22 by its closing will. Pins 62A and 62B, located at the ends of pivot arms 64a and 64b, slide into slots 44A and 44A 44b in the front part of the cassette halves 46A and 46B and release the inner cassette locking mechanism (not shown in the drawing)

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mechanism that holds the cassette halves together. If this has happened, the cassette halves can be pivoted apart about the pivot point 47 so that the unwinding tape roll to the capstan can be pushed forward and pressed against it.

The supply tape roll 42 is brought into an operative position in which its outer tape wrap is in close contact with the capstan 10 stands, which is caused by the fact that the Abwxckelschlxtten 23 in a pivoting movement by the tension spring 11 with a constant spring force is pressed against the capstan.

Figure 2, 3 and 4 show particularly clearly a device for Control of the sequence of operations in the operation of the tape drive. This device comprises a rotatable lead screw 50 with a spindle nut provided with a corresponding internal thread 51, which can be moved back and forth on the spindle. The spindle 50 is driven by a motor 52 via drive belt 53 and pulley 54, which is attached to one end of the spindle 50. The other end of the spindle 50 is supported by bearings 55 rotatably mounted on the frame 12 of the drive.

The spindle nut 51 has a circular cross-section, wherein the threads of the internal thread are formed perpendicular to the longitudinal axis of the spindle nut. The rotation of the spindle nut around the rotating spindle 50 is prevented by a pin 56, which protrudes from the nut and slides along the slot 57 provided in the frame of the drive when the spindle nut is 51 moved back and forth on Spindel'50.

Due to the pivoting moment exerted by the tension spring 11, the unwinding slide with its projection 26 is against the spindle nut 51 pressed. Thus, when the nut 51 moves to / from the capstan, it also controls the movement of the unwind carriage 23 and the tape roll 42 towards the capstan and away from it.

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The system for opening the clamshell box 41 is described below. The unwinding slide 23 has a rounded plate 27 arranged somewhat above the slide projection 26 and acts mechanically together with the flange part 63 of the pivot arm 64A. The extension 65 of the swing arm 64B is against the other Side of the flange, which in turn is against the slide plate 27 exerts a moment, namely the torque exerted on the arms by springs 67A and 67B. When the carriage 23 is moved towards the capstan, arms 64A and 64B pivot about their pivot points 66A and 66B so that the two halves of the cassette 41 pivot apart about their joint 47.

As soon as the cassette 4l is inserted into the drive in the manner described above during operation, the drive motor 52 becomes turned on so that the spindle 50 moves in the forward direction rotates so that the spindle nut 51 migrates along the spindle to the capstan 10. This is the initial situation of the charging process shown in Figures 2A, 3A and 4A.

While the nut 51 is moving toward the capstan, the unwinding carriage 23 moves the tape roll 42 to the capstan approach, to the extent that the slide projection 26 of the nut 51 follows. As the unwind carriage 23 moves toward the capstan, the arms 64A and 64B can pivot outward, causing the Cassette 41 is opened so far about its pivot point 47 that the tape roll 42 can be brought into contact with the capstan. The opening process is ended when the stop pins 68A and 68B on the pivot arms reach the end of the pivot slots 69A and 69B, respectively reach.

When the tape roll 42 is in contact with the capstan 10, as shown in Figures 2B, 3B and 4b, the nut 51 stops on its way to the capstan, as a result of the activation of the logic circuit 80, via which the operation of the lead screw motor 52 electrically is controlled. The logic circuit 80 consists of well-known AND, OR, NAND and NOR gates as well as FLIP-FLOPS which start, stop

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and control forward-backward movement of the spindle motor, the in turn, the movement of the spindle nut 51 on the spindle 50 controls depending on electrical signals that originate from several simple signal levels.

The first of these signal stages 81 comes into operation when the tape roll comes into contact with the capstan. Signal stage 81 essentially consists of a contact switch, the first contact of which is the spindle nut 51 and the second contact of which is formed by the slide projection 26. It can best be seen from Figure ^ B that when the tape roll k2 contacts the capstan 10, the unwinding carriage 23 will be blocked when the nut 51 moves further towards the capstan. So when the tape roll arrives at the capstan, the inevitable interruption of the contact between carriage projection 26 and nut 51- Since these parts, as stated above, serve as switch contacts, the circuit is interrupted when the spindle nut 51 moves further towards the capstan, whereby the Logic circuit receives a signal to switch off the spindle motor.

After the spindle motor has been switched off, the logic circuit 80 triggers the rotation of the capstan and thus directs the threading of the tape around the capstan to the take-up roll.

A second signal stage 82 comes into operation when the threading process has ended. It consists of a photo element 83 and a light source 8 ¹ I, which is arranged around the tape guide 14 on the opposite side of the tape path. By using a transparent leader tape and a non-transparent recording tape, this arrangement enables the connection point between leader tape and magnetic tape to be recognized by means of the photo element. A detection signal can also be generated by removing the magnetic layer at a specific point on the transparent tape substrate. The length of the transparent leader tape or ¹ "· the distance between the end of the leader tape and the transparent tape location is expediently so large

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to choose that the completion of the threading process is guaranteed before the detection signal is generated by the photocell.

When the photocell circuit emits the detection signal, the threading process is thus correctly completed. Then the logic circuit controls the spindle motor in the reverse direction of rotation so that the nut 51 comes into contact with the carriage projection 26 and thus begins to move the roll of tape k2 back, that is, in the direction away from the capstan 10. By the re-establishment of contact between nut 51 and projection 26 the logic circuit 81 is activated by a signal and stops the spindle motor. In practice, a slight overrun of the spindle nut 51 is usually sufficient to reduce the close contact between the unwinding roll and the capstan to such an extent that any slack in the tape can then be eliminated. However, the logic circuit 80 can also be designed with a signal delay device for temporarily canceling the contact if the practical further movement of the spindle nut 51 is not sufficient to tension the strap.

As soon as the close frictional contact between capstan 10 and tape roll 42 is reduced or canceled, the tape loop removal or the tape tensioning process begins by actuating the on the unwinding shaft 22 acting brake 70. This consists essentially of a flexible band that runs several times around the lower end of the shaft 22 is looped, so that a Kind of friction bearing is created, and the tape ends are resiliently attached to the drive frame. The movement-inhibiting effect of the brake 70 on shaft 22 eliminates any tape loops in the drive when take-up reel 30 and capstan 10 underneath the magnetic tape pull off the tape tension generated by the brake 70 from the unwinding roll as soon as the frictional engagement between the tape roll and the capstan is reduced or is canceled. If the latter is the case, the elimination of the slack ligament is terminated very quickly by the Logic circuit in turn, the forward movement of the spindle motor and the nut 51 controls, whereby the tape reel comes back to its operative position in close contact with dev, capstan.

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The end of the tape tensioning process can be recognized and indicated by a simple time control arrangement, for example by a further transparent point or a window on the tape at a predetermined distance from the start of the tape. In a practical embodiment, such a transparent window 85, ¹ I cm from the beginning of the tape located on the tape already be present, which, however, is primarily used for controlling the rewinding. When the above-described photocell circuit reports the appearance of this transparent window to the logic circuit 80, the latter causes the spindle motor 52 to move the nut 51 and thus the carriage projection 26 forward until close contact between the ribbon roll 42 and the capstan 10 is restored. The spindle nut 51 is then moved further on the spindle 50, is displayed until the end of the movement by tripping the limit switch 85 (see Fig. 3B and kB in the 'designated 51 end position of the spindle nut 51). By closing the limit switch 85, a signal for switching off the spindle motor 52 is fed to the logic circuit 80, whereby the movement of the nut 51 is also terminated, apart from the above-mentioned overrun. In the embodiment of the invention shown in the drawings, the distance that the nut 51 must be moved on the guide spindle 50 after the tape roll has been pressed against the capstan, must be large enough so that a defined between the carriage projection 26 and the nut 51 There is clearance when the tape is unwound from the hub 21.

When the tape cartridge is to be removed from the drive, the loading order described above is reversed as follows. After the magnetic tape and leader tape have been completely rewound onto the unwinding roll U2 , the photocell 82 generates the detection signal in the manner described above when the end of the tape with the layer-free position is transported past. With this signal, the logic circuit 80 begins to control the spindle motor 52 in reverse so that the spindle nut 51 moves on the spindle 50 in the direction of the capstan. The nut 51 again comes into contact with the slide projection 26,

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thereby moving the supply roll 42 back away from the capstan into the cassette. The cassette is then closed mechanically by the swivel arms 64A and 64B, which work in reverse order and which swivel the cassette ^{halves 1} JoA and 46B together again.

The completion of the unloading process is indicated by the fact that nut 51 actuates the limit switch 86 at the outer end of its path on the lead screw 50 (see FIG. ¹ YES). By closing this second limit switch, the logic circuit 80 is supplied with a signal for switching off the spindle motor, whereby the spindle nut 51 is also stopped in its movement. The door 61 is then to be opened, and the cassette with the tape roll 42 can be removed from the cassette receiving device.

BASF Aktiengesellschaft

Sign.

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Claims (2)

• · ■ ■■ · mi Ii lilt BIB »* ·· ι sai · in ο oiai lit · · OO SI« Χ »· G 77 13 667Ö O.Z. 32 56θ claims for protection 1. Magnetic tape transport according to the contact winding principle with automatic threading of a magnetic tape with EiGfädelvorspannband, essentially consisting of a frame., A winding roller in a cassette and a winding roller, at least one circular, rotating tape drive roller (capstan) for the simultaneous drive of both rollers by contact pressure on the respective Roller circumference, as well as a detachment device for the threading leader tape, wherein the tape drive roller and the rollers are mounted on rotatable shafts and the shafts of the rollers are movably arranged on carriers opposite the stationary shaft of the tape drive roller, so that a change in distance between the tape drive roller and the rollers takes place during the tape transport , and consisting of means for generating compressive forces at the contact points between the tape drive roller and the rollers and a tape span only, ^ in the tape section between the contact points, and wherein the cassette consists of two halves and an opening device for the cassette is provided, characterized in that the opening device consists of at least one movably mounted, in its rest position (Fig. 3 A) by means of an operator device (67 A, 67 B) in the opening direction of the cassette (41) prestressed opening element (64 A, 64 B) which engages on a cassette half (46 A or 46 B), and that the carrier ( 23) of the unwinding roller (42) in the loading position (Fig. 3 A) of the cassette (41) holds the opening element (64 A, 64 B) in its rest position and the opening element can be released by moving the carrier (23) towards the capstan , whereby the cassette (41) by means of the spring device (67 A or 67 B) is opened (Fig. 3 B). 7713667 06/29/78 • a st- ti · »■ ι * ι ι 33 If. «JlS - 2 - O.Z. 32 56ο % ■ 2. Belt conveyor according to claim 1, characterized in that j a motorized spindle and spindle nut device ff (50, 51, 52) for executing the threading in and threading out processes f is provided by moving the carrier (23), and that the Spindle nut (51) and part (26) of the carrier (23) of the unwinding roll (42) as contacts of an electrical switch (8l) are designed to generate time sequence signals which are dependent on the sequence of the tape transport movements. 3. Tape transport according to claims 1 and 2, characterized in that the cassette opening device comprises two arms ( ^6h 1 and 64 B) which engage the corner parts of the cassette halves (46 A or 46 B) of the cassette. 4. Tape transport according to claims 1-3. « Characterized in that a brake acting on the unwinding roller is provided, by means of which at least part of the tape tension can be generated. 5. tape transport according to claims 1 and 2, characterized in that the spindle nut (51) and the part (26) of the carrier (23) of the unwinding roll (42) are arranged to one another in such a way that upon movement of the spindle nut (5I) on the spindle (50) the carrier (23) and thus the tape roll (42) can be moved relative to the capstan (10). 6. tape transport according to one or more of claims 1-5> characterized in that at least one limit switch (85 or 86) is provided which is arranged on the path of the spindle nut (51) can be actuated by this. 7713667 06/29/78