DK142517B - MAGNETIC TAPE CASSETTE AND TAPE MACHINE FOR THE CASSETTE - Google Patents

Description

(11) PRESENTATION 142517

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DENMARK <">" «« · * · ii b 23 / M

(21) Application No. 6722/74 (22) Filed on 20th Dec. 1974 (24) Life Day 20 Dec. 1974 (44) The application presented and _, .pn

the petition published on * C · HOV. 1 yOU

PATENT AND TRADE MARKET <30> Pnontet requested from it

Dec 22 1973 * 2364597, DE

(71) BASF AKTIENGESELLSCHAFT, Carl-Bosch-Strasse 58, 67ΟΟ Ludwigshafen, DE.

(72) Inventor: Klans Schoettle, Ladenburger Strasse 70, 69ΟΟ Heidelberg, DE: Heinrich WitTkamp, Standenweg 33, 6800 Mannheim 34, DE: Karl Uhi, Pierstrasse 8H, 6710 Frankenthal, DE: Gerhard Rotter, Dubliner Stras = se 23, 67ΟΟ Ludwigshafen, DE: Robert Gertz, ErTcson Way, 25012 La = guna Hiils, California, US.

(74) Plenipotentiary in the proceedings:

Hofman-Bang & Boutard Engineering Company. _ (54) Magnetic tape cassette and tape cassette machine.

The invention relates to a magnetic tape cassette of the kind specified in the preamble of claim 1. A tape cassette of this type and a corresponding tape conveyor on a tape machine are disclosed in German Publication No. 1,955,560. The cassette described herein has a circular shape and a side opening for inserting a drive roller into the cassette for rotating a unwinding coil located in the cassette and for extending the tape out of the cassette. The side opening cannot be closed and the cassette is closed during playback. By means of pins, the unwinding coil is pivotally mounted in openings in the circular walls of the cassette, but is inseparably mounted. The movement of the coil in the direction of the drive roller due to the decreasing diameter of the tape roll required by the tape roll is provided by controlled displacement of the entire cassette by means of guide pins on the circular of the cassette. „142517 bottom wall and a control note cooperating with the guide pins in the top wall of the tape machine cassette, and by means of guide ribs which grip the cassette from the side.

In all embodiments of this known tape conveying arrangement, the exterior of the cassette housing is affected by spring-actuated shear elements so that the tape roll itself is only indirectly held pressed against the drive roll. As a primitive bearing means, the tape spool has the bearing pins mentioned above which engage openings in the circular walls of the cartridge. This known tape transport arrangement has significant disadvantages which consist in the fact that a) the tape and the tape spool as a whole within the cassette are not adequately protected against external effects; b) the cassette cannot be manufactured cheaply e.g. of plastic for a high rotational speed of the tape roll in the cassette due to the primitive bearing means for the coil; (c) obtaining an approximately frictionless guide of the cassette on the conveyor of the tape machine is very costly; (d) the drive roll must project into the cassette; the cassette opening and the dimensions of the drive roller must therefore be closely matched to one another; e) complicated and costly maneuvering means are required due to the movable bearing of the cassette on the tape machine, making the operation difficult.

The present invention aims to improve tape machines in which cassettes of the kind set forth in the preamble of claim 1 are used, in particular to make these tape machines more functional, the cassettes easier to handle and archive, and to provide cassettes that can be manufactured inexpensively. big series. This is achieved by designing the cassette as set forth in the characterizing part of claim 1. This provides the greatest possible security for the magnetic tape roll, the cassette and the tape machine, great functional safety during the application of the cassette to the tape machine and a simple and safe handling. The magnetic tape cassette is also easy to archive outside the tape machine. In the cassette of the invention, the magnetic tape and records thereof are effectively protected, even when the tape and tape machine are handled by unskilled amateurs or children.

The tape roll is effectively fixed in the cassette and thus protected from • mechanical damage, whether the cassette is placed on the tape machine or removed from it.

By the two springs as defined in claim 2, which are spaced as far apart as possible, the two halves of the cassette housing are affected with the greatest possible closing force and the stiffness of the overall cassette housing is increased against bending forces and forces which seek to displace the two cassette halves relative to each other.

The embodiment of the second spring as claimed in claim 3 and those with this cooperating lugs and projections are particularly advantageous in economical and operational terms.

Also, the one of claim 4 contributes to further increasing the stiffness of the cartridge.

In accordance with claim 5, an unintentional unwinding of the magnetic tape roll in the cassette is prevented.

The invention also relates to a tape machine for use with the cassette according to the invention. This tape machine has a device for receiving the cassette according to the invention, a drive means for rotating the cassette magnetic tape roll and at least one magnetic head and is characterized by the characterizing part of claim 7. The tape machine's recording device is very functional, as it ensures a trouble-free opening of the cassette when it is inserted into the tape machine so that damage to the unwound portions of the magnetic tape or the tape reel itself during playback or recording is excluded.

In the following, the invention will be explained in more detail with reference to the drawing, in which FIG. 1 shows an embodiment of the tape cassette according to the invention as well as parts of a tape machine serving the cassette; FIG. 2 is a vertical section through the cassette mounted in the tape machine; FIG. 3 is a top view and in the closed position, FIG. 4 is a top view of the cassette of FIG. 3, but in the open position, and i function on the tape machine; fig. 5 shows a closure spring associated with the cartridge; FIG. 6 cartridge parts with teeth, and fig. 7 shows a magnetic tape coil with a retractable tape for placement in the cassette.

FIG. 1 shows a tape cassette 2 and parts of a tape machine not otherwise shown for accommodating the cassette. The said parts of the tape machine include a lid 1 which serves as a lid, which in the open position shown releases a flat recess 3, in which the cassette 2 is laid manually in the embodiment of FIG. 1 is closed. The recess 3 is bifurcated and is preferably formed of punched and bent eyes. The two bottom portions 3a and 3b of the recess are pivotable independently of a common vertical shaft 4 and are pivotally connected to the flap 1 by 7. On each bracket 6 on the respective part 3a and 3b, respectively, the connecting rod 5 is pivotally connected. in that the two parts 3a and 3b of the recess are joined and abut with their opposite edges to form the recess when the flap 1 is open. In this position, the recess is ready to receive the cassette 2. If the flap 1 is pivoted in the direction of the arrow a towards the closed position, the bottom parts 3a and 3b are pivoted away from each other around the pivot shaft 4 in the direction of the arrows b, the two parts being pivoted to the same angle. each side by displacing the rods 5 in the direction of the arrows c. The common pivot shaft 4 of the bottom members aligns - when the cassette is positioned in the recess - with a vertical hinge shaft 8, at which two cassette halves are interconnected and about which they can pivot horizontally away from c 142517 5 each other and against each other. The opening angle between the two halves of the cassette in the maximum open position corresponds to the opening angle between the bottom portions 3a and 3b. During the oscillation of the bottom members, two stationary holding means 9 are caused to engage about each of its bottom members and each cassette half, so that they are held in a certain height position, in which from one of FIG. 7, magnetic tape coil arranged in the cassette can be wound magnetic tape or wound tape on the coil without the tape thereby contacting the cassette housing parts.

The cassette 2 is inserted diagonally 3 from above with a forward cassette front 17, whereby the respective cassette side is pushed down below a portion 10 extending over the recess of the recess end wall. At the same time, noses 11 are pushed in through each opening respectively to the right and to the left of the cassette, and shoots a spring placed in the cassette so far back that the cassette is ready to open when properly inserted into the recess. To prevent the cartridge from being loaded in the wrong position, e.g. in the mirrored position, the cassette has on its one side a recess 12, while in the recess of the tape machine for the cassette on that side there is a projection 13. When the cassette 2 is inserted in the recess, a pressure ball mechanism 16 is activated. 2, on a tape coil bearing 14, whereby the tape coil of FIG. 7 denoted by 15, the coil jaws are pressed against a peripheral cone stub surface on the band split bed 14. The embodiment shown in FIG. 7 with 18 designated magnetic tape coil is now ready for operation in the tape machine.

A spring-actuated locking arm 19 on the tape machine further ensures that the cassette housing 2 in the recess of the tape machine is placed in its correct end position. By means of the arm 19 in conjunction with a belt change mechanism not shown, the belt machine can be locked so that it cannot be operated as long as the cassette 2 is not positioned correctly.

The described cartridge loading structure, described in more detail below, may be configured differently. Cartridge 2 is a so-called one-hole cartridge. The FIG. 7, the magnetic tape shown in coil 7 is wound on a tape or coil core 15, preferably an aluminum core and in the form of a roller 18. At its outer edge 6, the tape roller or coil 18 carries an insertion bias strip 20 with the edge teeth facing the coil by means of which the insertion strip 20 is held on the edges of the magnetic tape coil itself, holding the roller 18 together so that the outermost magnetic tape turns do not fall off. When the cartridge 2 is closed as shown in FIG. 3, the coil core 15 is retained by means of ribs not shown between the top wall 21 of the cassette and bottom wall 22 so that the core 15 is extensively secured in its position against displacement and rotation as the cassette is moved. The ribbon coil 18 may be further secured against rotation by means of teeth not shown on the underside of the core 15, which engage with corresponding recesses in the bottom wall 22 of the cassette or intervene between projections on said bottom wall. The cassette 2, as mentioned, consists of two equal parts pivotally connected to each other by a hinge 26. Conveniently, the cassette halves each consist of two parts which are firmly connected to each other according to the injection molding method, e.g. by ultrasonic welding or by constriction. In their closed position, the cassette halves completely enclose the tape coil 18 such that the tape is nowhere directly accessible from the outside. In this way, the tape spool 18 is optimally protected against mechanical overload and dust. Along the dividing line between the two halves of the cassette, teeth 25 are formed on each half edge, which are interspersed at intervals between two adjacent teeth on the other half. These teeth are found on both the bottom wall of the cassette and on the top wall of the cassette, cf. FIG. 3, 4 and 6. In FIG. 6, the engagement movement is indicated by arrows d. In this measure, the mechanical strength of the cassette 2 is increased in the partition plane as well as the dustproofness and the safety against mechanical damage to the magnetic tape, as can be seen in particular in fig. 6. The described tooth can also be realized in another way, e.g. by feder-not connections. To further secure the cassette 2 against deformation in the partition plane between its two halves, partly a closing spring 27 serves in the vicinity of the hinge 26, e.g. a leaf spring, the two ends of which engage each groove 28 in each cassette half, and partly a front spring 29. The closing spring 27 holds the teeth 25 in engagement with each other, while the spring 29, the shape of which is shown in FIG. 5, in the closed position of the cassette is clamped between two wedge-shaped projections 30; 3 and 4, which engage an elongate aperture 32, FIG. 5 in the spring 29 in the vicinity of each end edge 31. The projections 30, which are directed to each cassette side wall 33, Fig. 3, compensate in a simple manner for the inevitable length tolerances of the springs 29. The rectangular aperture 32 of the spring 29 is of such size that at least a portion of the ribbon coil 18 can protrude through the aperture 32 without the band windings or bias strip 20 touching the edges of the aperture. The spring 29 is slightly curved in the resting position so that it supports against the inner surface of the end wall 17 of the cassette and thus helps to hold the teeth 25 in engagement with each other when the cassette 2 is closed.

To open the cassette, the slides shown in FIG. 1, each of the noses 11 shown through each slot 34 located at each end of the spring 29, whereby the spring is curved and thereby disengaged with the wedge-shaped projections 30. When the two bottom portions of the cassette are then pivoted away from each other, two small, also wedge-shaped, restriction projections 35 in engagement with each end edge 31 of the opening 32 of the spring 29, the oscillating movement of the cassette bottom portions outwardly, i.e. apart, stop. The spring 29 has an inwardly bent end portion at both ends, FIG. 5, with which the spring slides across the wedge surface of the projection 35, until the respective end edge 31 of the spring aperture engages the wedge end surface as shown in FIG. 4th

It can be seen from FIG. 3, that the clearance between the upper and lower longitudinal edges of the springs 27 and 29 and the top wall of the cassette and its bottom wall, respectively, is so small that even a slight bending of the top wall and the bottom wall will bring the said spring edges into abutment against the inside of the walls, thereby effectively supporting the cassette against further bending. The spring 29 may also be configured differently, e.g. as a rectangular wire frame. Instead of the spring opening 32, a U-shaped recess can be found. In the manufacture of the cassette, the spring 29 can be inserted into the otherwise finished cassette 2. The spring 29 can be removed by a special tool, e.g. when damaged and must be replaced by another spring, for repairing the cartridge or for replacing the tape coil 18.

To compensate for different tape coil diameters due to different tape thickness or tape length (for example, with recorded tapes), one preferably of plastic, e.g. polyester consisting of spring 36, FIG. 3 and 4, which, depending on the belt coil diameter, are located at different distance 8 from the center of the coil and held between projections 37 such that the hand coil 18, when the cassette is closed, abuts with its periphery against the springs 36 and is thereby held together so that the insertion strip cannot loosen up. The holding springs 36 may not have edge tabs projecting above and below the belt coil. When the cassette is in the one shown in FIG. 4, for the recording or playback of the tape, the springs 36 are retracted from the tape periphery.

A comparison of the position of the band coil 18 in FIG. 3 and in FIG. 4 shows that the tape spool 18 of FIG. 4 is projected out through the angular aperture 38 of the cassette 2 and with its periphery abuts the germ indicated by semicircular circumference 39 on a drive roller, a so-called capstan roller, on the tape machine itself. This drive roller is the common drive means for a two belt coils of a magnetic tape machine operating according to the contact winding principle. In the case of a magnetic tape machine of this type, in order to ensure a sufficiently large contact pressure between the drive roller and the tape coils, the latter is required during rewinding or rewinding, i.e. by decreasing and increasing belt coil diameter, respectively, can be moved towards and away from the drive roller.

In such a tape machine, the tape reel sheaths of the tape machine itself are slidably mounted in such a way that they can move radially toward or, away from the drive roller, and spring applied in the direction thereof.

In FIG. 4, the shaft 40 for the tape coil core 15 is thus slidable along the center axis 41 in the direction of the drive roller for displacing the tape coil core 15 in the sector between the two cassette halves of the embodiment shown in FIG. 4. The insert strip 20 is removed from the ribbon coil by means of a knife-shaped scraper 42; 4, after which the strip 20 is guided around the drive roll by means of the control means (not shown) and attached to a second coil core not shown, on which the tape is wound after playback or recording. The insert strip consists of plastic film, the thickness of which is usually greater than that of the magnetic tape itself, and which is attached thereto in a known manner. In the special construction of the cassette 2, care has been taken to ensure that the insertion strip 20 cannot detach from the periphery of the magnetic tape coil within the cassette itself, in particular the springs 36 keep the magnetic tape windings pressed together. Consequently, the distance between the peripheral of the magnetic tape coil and the inner surfaces of the cassette walls is adapted.

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seen that the insertion strip is held to abut against the magnetic tape roller. Also, the other spaces between the hand coil and the various parts of the cassette are dimensioned so that the insertion strip cannot snag or detach if the handset is improperly rotated in the wrong direction even when the free end portion of the insertion strip protrudes somewhat from the periphery of the magnetic tape reel itself.

A loosening of the insertion strip prior to the thread operation in the tape machine would cause malfunction of the preferably automatic tape transport. When the entire magnetic tape is unwound, the empty coil body 15 abuts against the periphery of the drive roller. The magnetic tape can now be transported back from the coil core on which it has been wound to the coil core 15 of cassette 2 until the full tape coil diameter is restored.

The tape cassette described above is particularly advantageous in that the magnetic tape coil prior to cassette insertion into the tape machine is securely protected from all external adverse effects such as dust, dirt and mechanical damage and that the cassette inserted into the tape machine can be handled extensively automatically with great reliability. In this way, both the tape cassette and the tape machine are best protected against improper operation. The cassette and the parts of the tape machine that must be adapted to the special design of the cassette are easy and inexpensive to manufacture in serial production. A further significant advantage over the state of the art is that the cassette is locked to the tape machine and that only the magnetic tape coil itself has to be displaced, thereby eliminating various otherwise necessary controls and simplifying the operation itself.

The cassette can also be manufactured without the FIG. 4, openings 45, 44 for the belt reel bearing 14 or shaft 40.

Claims (4)

Patent Claims: A magnetic tape cassette (2) for a tape machine and having a cassette housing with a top wall (21), a bottom wall (22) and side walls (33) which together enclose a magnetic tape roller (18) wound on a coil core (15) the cassette is positioned in its position in the tape machine - is or may be brought into a position in which it is in contact with its periphery with a drive member of the tape machine, the cassette (2) consisting of a hinge (26), in the horizontal plane, mutually lockable and lockable halves of approximately the same volume, and in which there is an opening (44 and 45, respectively) in the cassette bottom wall (22) and / or top wall (21), through which a shaft (40) for displacing and storing the coil core (15) projecting into the cassette and into a carrier aperture (45) in the coil core, characterized in that retaining means (56 and 57) are arranged and positioned in the cassette to hold the magnetic tape roller (18) ) in a central position ion in the cassette when it is closed, and in that the cassette has a locking mechanism (29, 30, 55) arranged to explicitly hold the cassette halves in a closed position or in a pivoted open cassette position, and to be extruded by means of of maneuvering means (11) on the tape machine. Magnetic tape cassette according to claim 1, characterized in that the locking mechanism includes two springs (27 and 29) which act on the cassette halves towards the closed cassette position and one spring (27) is arranged in the vicinity of the hinge (26) while the second spring (29) is disposed on the opposite side of the cassette halves. Magnetic tape cassette according to claim 2, characterized in that the second spring (29) has a flush opening (52) with a gap between the halves of the open cassette of such shape and size that the tape roll (18) when the cassette (2) is open, at least partially extendable through this opening (32), and in that the spring (29) in the closed position of the cassette engages two wedge-shaped lugs (30) disposed on each cassette half and in the open position of the cassette is in engagement with two other, also wedge-shaped projections (35).