DE8713840U1 - Cleaning device for cassette tape recorders - Google Patents

Description

Description

The invention relates generally to a cleaning cassette for cleaning playback and/or recording units and in particular to a cleaning device for cleaning the playback/recording head, the erase head and the drive and pressure roller, with the common feature that each individual cleaning element is composed of a cleaning head holder with a replaceable cotton-tipped rod inserted therein, the cleaning element being able to be attached to different positions for the corresponding 2-jeck.

types of bases can be arranged and secured.

The invention serves three purposes, namely, cleaning (a) the playback/recording head, (b) the drive and pinch rollers, and (c) the erase head, and the—

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Accordingly, the state of the art is explained with regard to the three corresponding applications.

Initially, the so-called "cleaning tape cassettes" were used to clean the magnetic heads. In this case, a tape with abrasive properties is used instead of the usual magnetic tape in the cassette, which is unwound in contact with the surfaces to be cleaned. The cleaning was carried out by friction with only a small effect. Later, pads made of felt material were provided for cleaning, but their low ability to absorb solvents limited their use. Now cleaning cassettes of the new type are used. As far as the material is concerned, cotton is preferred in the invention because of its excellent absorption capacity.

For cleaning the playback/recording head of a playback/recording unit, devices are known in which a wiper arm is pivotally mounted for reciprocating movement in a cassette-like housing. A cleaning pad is attached to one end of the wiper arm, which wipes back and forth over the head of the unit. It is desirable that the cleaning pad _is held securely on the wiper arm and it is further ^desirable that the cleaning pad is cleaned at intervals,

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after a number of cleaning processes have been carried out. Devices with the above-mentioned features may already be known from the state of the art, but the cleaning pad is hardly held securely enough on the wiper arm and the close contact of the pad with the surface of the components to be cleaned can hardly be ensured.

Secondly, in known facilities for cleaning

The drive and pinch rollers of a record/playback unit normally have a pair of cleaning pads designed to engage the drive and pinch rollers respectively. These pads may be mounted on a suitable mounting structure. However, there are associated disadvantages in terms of poor contact and non-replaceability.

Thirdly, cleaning devices for recording playback units with automatic switching j

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wherein the cleaning device has two drive and;

two pressure rollers. The pads of this device also have the disadvantages of insufficient contact, insecure mounting and lack of replaceability.

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Accordingly, the main object of the invention is to provide a versatile cleaning device which can be used for cleaning the playback/recording head, the drive and pressure rollers and the erase head and which comprises a matchstick-like rod with a cotton pad attached thereto, the rod being movably but firmly received in a tubular holder which has a beveled inner wall to ensure that the rod is firmly seated. One side of the outer wall of the tubular holder is provided with a locking device such as a stamped elastic tongue with a protruding locking element. On the opposite side of the outer wall, an upper and a lower cutout are formed thereon, the purpose of which will be explained in detail later. Regardless of the purpose of the cleaning device, the tubular tip holder is a basic concept that can be universally used in cleaning the playback/recording head, the drive and pinch roller, and the erase head.

Another aspect of the invention is to provide a first type of holder bases which are arranged in pairs, side by side and offset from each other in a position directly at the location of the drive and pressure rollers

for cleaning them. These bases are formed by two longitudinally cut half-cylinders, which are arranged in pairs in blocks within the halves of the
cleaning cassette. Each base is fitted with a compression spring for pre-tensioning against the

lower end of the inserted holder so that the cotton tip is pressed firmly against the surface to be cleaned.

According to the invention, in each half-cylinder pair a

side slot for receiving a spring-loaded, wing-like lock or a spring-loaded locking rod, which can be used for optional engagement with the upper or lower cutout of the holder wall for securing
a predetermined position and to release the lock

serves when the pressure roller to be cleaned is pressed against the cleaning tip, so that during C^s cleaning process both
the drive and pressure rollers are held in firm engagement with the tips, which can now move freely up and down. Furthermore, another pair of half cylinders is provided with a longitudinal slot to facilitate insertion from the outside of the
Base wall by means of a pointed object through the slot and to prevent the protruding locking device formed on the elastic tongue of the holder wall from engaging with the upper edge of the slot

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to be loosened ₄ so that the pin holder is pushed out for replacement due to the pressure of the* tension spring.

Furthermore, another tip holder base block is provided with a cylindrical interior and a

As explained above, a longitudinal slot for holding the tip holder assembly, wherein the protruding locking device on the holder tongue is received by the upper edge of the slot and is secured by means of a

· pushed in a sharp object. This

1 Construction is essentially the same as the first type of base, except that the lower end of the block is extended to form a wiper arm which is pivotally mounted for reciprocating movement to clean the playback/recording head. The lower end of the wiper arm is actuated and driven by a pair of opposed eccentric gears, each of which is integrally formed with one of a pair of driven gears which mesh with a pair of main drive gears driven by the drive spindles of the playback/recording device.

Furthermore, according to the invention, a third type of tip holder base is provided, which has an abbreviated

The area under the pivot of the second type wiper arm is omitted because the arm is not directly driven by gear trains. However, a connecting device such as a connecting rod is provided between the second type arm and the third type arm with bearing eyes arranged on the sides of each arm. In this way, a connecting parallelogram is formed, which causes the short arm of the third type socket to move together with the pivoting movement of the second type wiper arm for cleaning the erase head.

Embodiments of the invention are explained with reference to the accompanying drawings. They show:

Fig. 1 is an enlarged view of a cleaning cassette for use with the cleaning device according to the invention for cleaning the playback/recording head of a cassette tape recorder with automatic switching (auto reverse) as well as for cleaning its drive and pressure

role; the drive mechanism is also shown;

Fig. 2A is an enlarged partial plan view of the cleaning device of Fig. 1, with the cleaning tips in close engagement with the surfaces of the drive roller, the pinch roller and the playback/recording head; the

drive device not shown;

Fig. 2B shows a corresponding front view;

Fig. 3A is an enlarged partial plan view of a cleaning cassette for cleaning the playback/recording head and the erase head; this tape device

is of a "general" type with separate playback/recording head and erase head; the cleaning tips are in close contact with the surfaces to be cleaned and with the drive connectors shown;

Fig. 3B is a front view of Fig. 3A;

Fig. 4A is an exploded view of the main parts of a cleaning tip assembly including the stick-like tip and the holder in front view;

Fig. 4B is a side view of a cleaning tip assembly showing the cutouts and locking tab;

Fig _{. 4} 5 is a partial perspective view of the cleaning cassette device... steering in the relative arrangement of a pair of associated half cylinders or cylinder halves serves as a holding base for the cleaning tip arrangement;

Fig. 5A is a perspective view of another embodiment of the cleaning cassette arrangement with a locking rod.

Fig. 6 is a perspective view of the pivotally mounted wiper arm of the cleaning device for the playback/recording head, guided by a pair of associated eccentric wheels;

Fig. 6A is a perspective view of another embodiment of the wiper arm;

Fig. 6B is a plan view of a locking gear used therein;

Fig. 7 is a representation of a modified drive wheel to ensure a better transmission;

Fig. 8 is a sectional view of the drive of Fig. 7 to explain the gap for absorbing possible vibrations in the drive spindle.

In Fig. 1, a cleaning cassette 10 for use with the cleaning tip arrangement 20 according to the invention is shown with

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The drive device has the dual task of cleaning the drive and pressure rollers 32, 31 and the playback/recording head 33. However, as shown in detail in Figs. 3A and 3B, the drive device also serves the further purpose of cleaning the erase head 34.

The playback/recording head, the erase head, the drive and the pinch rollers are components of an ordinary, "generic" device and/or recording unit, only a part of which is shown at 30 for the purpose of illustration. A glance at Figs. 2A to 2B shows that in the corresponding positions in which accessible openings are provided, individual cleaning tip arrangements are shown, namely:

the cleaning tip assembly 22P-22C in positions 101-102 for the pinch roller 31 and the drive roller 32, the tip assembly 22H in position 103 for the playback/recording head 33, and, as shown in Figs. 3A-38, the tip assembly 22E in position 104 for the erase head 34.

The cleaning cassette has a cassette-like housing 10 which has the same general structure as a housing of a conventional tape cassette. For the sake of explanation, the cover of the housing 10 is shown in Fig. I

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not shown. The housing 10 has a front end 35, a rear end 38 and a left and a right side 36 and 37, respectively.

Regardless of the purpose of the cleaning device, the cleaning tip assembly 20, as shown in Fig. 4B, forms the main part of the invention. Fig. 4A shows an exploded view of the tip assembly 20, which includes a tubular holder 21 and a tip pin made of a cotton tip 221 rolled tightly around a matchstick-like rod 222, whereby suitable adhesives can be used to ensure the hold. The inner wall 211 of the tubular holder 21 is tapered inwardly to provide a

to ensure firm engagement when the

&Idigr; cotton-covered rod is inserted. A small opening 212 is provided in the bottom of the holder 21 to allow the rod 22 to be pushed out for replacement with a small pin. Fig. 4B shows another view of the tubular holder 21, on one side wall of which a locking device such as a U-shaped tongue punched out is provided, with a projecting lock 214 formed on the tongue 213. On the opposite side wall, an upper and a lower cutout 215, 216 is formed, the use of which will be explained later.

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The essential part of the invention, the cleaning tip assembly 20, is universally applicable for the above-mentioned purposes, with the seat or base being changed depending on the intended use. Of course, the cross-sectional shape of the tubular holder can be other than circular, e.g. triangular, square, octagonal, etc., with the base having a corresponding internal shape for receiving the holder.

A first type of socket 40 is described in detail with reference to Figs. 1, 2 and 5. In Fig. 5

the cassette housing 10 is opened to show its lower part .1.1 and its upper part 12. The seat or base 40 is divided into two halves 401 and 402, each consisting of a pair of offset base elements 403, 404 or 403', 404' when the cassette housing IO is connected to the lower part 11 and the

Upper part 12 is closed. The half cylinders 403-403',

| 404-404' together form cylindrical bases for holding cleaning tip assemblies 20. It is intended here

jj it can be established that, regardless of which

" Type of seat or base the tip assembly inserted

a compression spring 23 should be inserted underneath so that the tip arrangement can be elastically pre-tensioned against the surface to be cleaned. 25

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In the half 401 of the base 40 there is a round opening 407 which opens in the boundary of the wall connecting the half cylinders 403, 404, and laterally on the curvature of the semi-cylindrical walls there are a pair of spread-out, flight-like grooves 408 for receiving and holding a locking element 410 which is designed in the form of spread-out wings, and a central recess designed to receive a compression spring 409 which gives the element 410 elasticity so that the straight-defined wings 411, 412 can optionally engage in the upper or lower cutout 215, 216 or so that the tip arrangement 20 can slide over the rounded edges 413, 414 of the wing elements 411 and 412.

In Figs. 1 and 5A, an embodiment for replacing the wing-like locking element 410 is shown. A locking rod, which has two projections 411', 412' at one end, is elongated and flat and is inserted into grooves 408' of the half cylinders 403, 404. A bearing 415' for receiving the projections or pins 411', 412' of the locking rod 410' is arranged outside the half cylinder 403, 404. The bearing and the projections form a pivot point for the locking rod, which, like the wing-like locking element, is brought into engagement with the cleaning tip arrangement 208 by means of a torsion spring 409.

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In the half 402 of the base 40, the upper part of a longitudinal slot 421, 422 is cut through the entire wall of the cover 12, so that when the cassette halves 11 and 12 are closed, semi-cylindrical halves 403-403', 404-404' are formed through them, each of which receives a tip arrangement 20. On each tip arrangement 20, a protruding lock 214 is formed on the tongue 213, which can be brought into engagement with the upper edge 423, 424 of the slot 421, 422. This lock 214 can be activated by inserting a pointed object, e.g. a pencil tip, into the slot from outside the cover wall 12 and by sliding the elastic tongue 213 inwards.

&bull;^5. Before the cassette housing halves 11-12 are closed, a first tip assembly 2OC (22C) is inserted into the cylinder 404. The assembly 2OC is pushed downward until the top cutout 215 is engaged by the wing 412 of the latch 410.

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Another tip assembly 20P (22P) is then inserted into the cylinder 403 until its lower cutout 216 is engaged by the wing 411 of the locking mechanism 410. When the cleaning cassette is positioned in the cassette compartment, the tip 22C is located directly under the drive roller 32, while the pressure of the pressure roller 31 pushes the tip 22B further downwards so that the lower cutout of the holder 20P disengages from the locking wing 411 and forces the locking mechanism 410 into the opening 407; the upper cutout 215 of the holder 22C is also released. When the tips 22P

and 22C are disengaged and can move freely up and down, a neutral situation results. The springs 23 held in the lower part of the cylinders 405, 406 firmly preload the tips 22P and 22C against the pressure roller 31 and the drive roller 32, respectively, and complete cleaning is ensured.

Referring to Figs. 1 and 6, a second type of holder base 56 for the tips 22H used to clean the playback/recording head 33 is explained. The base holder 56 according to the second embodiment is also designed in the form of a block and has an inner space for receiving and holding a tip 23H. A tongue slot 56I is provided along the block 56 for inserting a pointed object and for releasing the tongue lock in the holder wall. The block 56 has at its other end an actuating arm 50 which is pivotally attached to a pin 57 in the central region of the housing 10. The lower end 58 of the arm 50 is cut to half its thickness and is guided by a pair of opposed eccentrics 54E- ^54E1 which are integral with a pair of driven gears 54-54' driven behind the lower end 58. The gears 54-54' are in turn driven by a pair of drive spindles 51-51'

&eacgr;&thgr; of the record/playback device. The swinging movement of the arm 50 is caused by the rotation of the opposing eccentrics 54E-54E■, whereby the cleaning tip 22H is moved back and forth over the play/record head 33. The arrangement of the eccentric pairs is complementary to one another so that they can guide the arm 50 in a push-pull movement.

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Another embodiment of the second holder base 56 is designated 56' in Fig. 6A, where it is formed as a cylindrical shape instead of in a block

w is. A fastening pin 562 of the cylinder 56'

5 extends downwards and is rotatable in a bearing

501. Attached to the pin 562 and rotatable

with it is a locking gear 59, which is accommodated in a recess 502 formed in the arm element 50. The lower end of the arm 50 is extended

10 and forms an actuating element 59 with half the thickness,

which is driven by a pair of complementary eccentrics 54E, 54E ¹ in the same manner as in Fig. 6.,

In Fig. 6B, a locking/actuating element 59a in the form of a leaf spring is arranged on the bottom of the cassette housing element 11 so that when the lever 58 swings around the pin 57, the locking gear temporarily comes into contact with the leaf spring 59a, so that the pin 562 is rotated with the base 56' by a corresponding angle; a retaining clamp 59b prevents the locking gear from moving into the

opposite direction. This changes the direction in which the cleaning tip comes into contact with the surface to be cleaned, ensuring excellent cleaning.

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This version should be used especially with recording/playback devices with switching (auto reverse).

A third embodiment of the tip holder base 66, as shown in Figs. 3A, 3B, is a shortened form of the second embodiment 56. A pivot pin 67 is provided for pivotally supporting the base, which serves to clean the erase head 34. The area below the pivot pin 57 of the wiper arm ■ of the second embodiment is omitted since the arm is not directly driven by gear trains. However, a connecting device such as the connecting rod 560 is provided between the base arm 56 of the second embodiment and the base arm 66 of the third embodiment, with a pair of fastening eyes 562, 662 arranged on the sides of the arms opposite each other. In this way, a connecting parallelogram is formed from the arm 56, the eyelet 562, the connecting rod 560, the eyelet 662, the arm 66 and the pivots 57, 67. The short arm 66 is moved in an oscillating manner together with the oscillating movement of the swivel arm 50 and causes the cleaning of the erase head 34. The connecting rod 560 can expand a clamping device at each end for connection to the eyelets as shown.

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In the case where the erase head 34 is not provided separately as in Figs. 3A and 3B and the playback/recording device is designed with two drive, pressure rollers, ie in an "auto-reverse type" device, a further pair of cleaning tips 22C, 22P ¹ can be provided in the positions 101', 102' (Fig. 2B).

Fig. 7 shows a modification of the drive gear 53, which is divided into: a gear ring 53a for engagement with the drive wheel 54, on which the guide 54E is formed as one piece, an additional cross gear 531 with crosswise arranged teeth 534 for engagement with the inner cross recess 533 of the gear 53a, the cross gear 531 in turn being driven by the drive spindle of the playback/recording device. This embodiment of the drive device provides an improvement in the transmission, whereby possible vibrations due to insufficient or only loosely meshing engagement can be eliminated and smooth operation is ensured.

The thickness t of the cross gear 531 is approximately 1/3 of the thickness T of the wheel 53a with the inner cross recess 533. The radius of the inner cross recess of the wheel 53a is referred to as R, while the outer radius of the cross gear 531 is r, where R > r and R- r = C* so that C

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indicates the gap between the wheels 531 and 53a. This structure increases the vibration absorption capacity of the wheel 531 due to the buffer function of the gap C, so that the wheel 53a can rotate without interference and can mesh uniformly with the following gears to be driven. This is particularly evident from the illustration in Fig. 8.

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Claims (9)

Protection claims 1. Cleaning device for cleaning a playback/recording head, an erase head and a drive/pressure roller, characterized by a cleaning tip arrangement with a rod provided with cotton at one tip and a tubular holding element holding the rod, wherein a base block receives and holds the cleaning tip arrangement and biasing, locking and oscillating devices ensure secure engagement of the cleaning tip with the surface to be cleaned and/or carry out a reciprocating wiping movement to carry out the cleaning. 2. Cleaning device according to claim 1, characterized in that the cleaning tip arrangement is provided with a wear-resistant cotton covered rod is securely inserted into the interior of the tubular holder, the inner wall of the holder being tapered downwards so that the rod is retained therein, and an opening is provided in the lower part of the holder through which the rod can be pushed out from below for replacement, an elastic locking element such as a U-shaped tongue with a lock protruding therefrom is punched out on one side of the outer wall of the holder to facilitate locking to an upper edge of the base, and upper and lower cutouts are provided on the outer wall, opposite the tongue lock, which can be brought into engagement with the locking device of the base or the seat for temporarily securing a position before cleaning of the pressure and drive rollers is carried out. 3. Cleaning device according to claim 1, characterized in that each base block has an inner cylindrical space for receiving and holding the cleaning tip arrangement and a longitudinal slot extending through the wall, the upper edge of which can be brought into engagement with the tongue lock on the holder outer side, the slot serving as an access for a pencil tip or the like to release the tongue lock _so that ti .·. «ti · I * · ä e i < « < rl« ■ Ii t· the upward force of a compression spring, which is arranged in the lower part of the base, pushes the cleaning tip arrangement outwards for replacement or the like. 4. Cleaning device according to claim 6 or 3, characterized in that the base consists of a pair of offset cylinders cut longitudinally into two half-cylinder halves and secured to the bottom and top of the cleaning cassette respectively so that when the cassette is closed they form a pair of cylindrical seats or bases for receiving and holding a pair of tip assemblies for cleaning the drive and pressure rollers. 5. Cleaning device according to claim 4, characterized characterized in that a pair of the half- | cylinder halves has a lateral slot with a central opening for receiving a spring-loaded wing-like or rod-like locking device, <üe can be brought into engagement with the upper or lower recess on the outside of the tubular holder of the corresponding tip arrangement to ensure a position so that the cleaning tips are firmly in the direction of the surface of the drive roller and the pressure &bull; i« Ii ·«·< &bull; * · ft · t roller when releasing the wing lock or locking rod when the tip assemblies are inserted into the seat. 6. Cleaning device according to claim 1 or 3, characterized in that the seat or base is pivotally mounted in the middle of the cassette, its lower end being extended to form a swing arm which is guided in a push-pull movement by a pair of complementarily arranged eccentrics which are formed integrally with a pair of driven wheels which in turn are driven by a pair of main drive wheels driven by the drive spindles of the playback/recording device, and that this device serves to clean the playback/recording head. 7. Cleaning device according to claim 6, characterized by a cylindrical seat or base with a pin which is received in a bearing on the wiper arm, a locking gear being attached to the pin which is held/moved by a leaf spring-like actuating element which is attached to the lower base of the cassette housing, so that during a swinging movement of the arm the locking gear temporarily contacts the leaf spring and the pin with the base is rotated by an angle from time to time. -A- 8» Cleaning device according to claim 6 or 7, characterized in that the main drive consists of a cross wheel and a wheel provided with cross recesses on the inside, whereby a gap is provided between the wheels so that the compensation of possible vibrations from the drive spindles is improved and an undisturbed and play-free transmission is ensured. 9. Cleaning device according to claim 1 or 3, characterized in that the actuating arm which extends behind the pivot is omitted, that a pair of connecting eyes are formed opposite each other on the sides of two bases, a connecting rod connecting the eyes, the second base is actuated by the first swing base by a parallelogram connection and is moved therewith in uniform movement for cleaning the erase head.