CH654136A5 - CASSETTE FOR CLEANING THE MEANS OF RECORDING AND / OR PLAYING MAGNETIC TAPES. - Google Patents

Description

The present invention relates to a cassette for cleaning the recording and / or reading means of magnetic tapes, more precisely a cassette according to the preamble of claim 1.

It is well known that the movement of a magnetic tape against its recording, reading and driving members creates deposits of iron oxide particles on them and that the accumulation of these deposits gives rise to to noise and / or distortion of the recorded signal and compromises the proper scrolling of the magnetic tape which must be carried out at a constant speed to obtain a good quality of reproduction.

To ensure the cleaning of these organs, cassettes or cartridges have already been proposed containing, in place of the magnetic strip, a so-called cleaning strip, associated with a stationary reservoir of cleaning liquid in permanent contact with the strip so as to 'soak of the said liquid during its movement (DE-OS 2 158 994).

However, it is found that a fixed tank does not ensure a homogeneous distribution of the cleaning liquid on the strip and therefore the cleaning efficiency is reduced.

On the other hand, this permanent and continuous contact is very often a source of serious problems when used in video recorders.

Indeed, the permanent and continuous application of any cleaning product on the strip, necessary to ensure effective cleaning, tends to make it adhesive, so that it wraps around the rotating elements (capstan, rollers pressure, video head drum, etc.). This generally results in either the cleaning tape or some parts of the device itself being damaged.

This phenomenon is particularly frequent in tape recorders where the playback and recording heads are generally mounted on drums with a diameter of 70 to 100 mm rotating at speeds of the order of 1,500 to 1,800 revolutions per minute.

Indeed, when a strip soaked in liquid is applied against the drum, it is immediately driven at the linear speed of the drum, and according to the figures cited above, it is understood that this strip is, in the space of a few tenths of a second, completely unwound from the cassette. This has the major disadvantages that:

- the tape is in the device since it is only rewound at very low speeds (a few centimeters per second) and because it risks damaging or deteriorating certain organs of the device;

- no cleaning has been carried out;

- the tape being unwound in the device, it is impossible to recover it and the device must be brought to a repairer.

The object of the present invention is to solve the problems mentioned above by proposing very reliable means which are very simple to implement.

With a view to achieving this aim, the cassette which is the subject of the invention is defined in claim 1.

. The tape is not soaked continuously but intermittently, it does not "stick" on the drums comprising the video heads and cleaning is carried out quite effectively.

In order to clearly understand the invention, an exemplary embodiment will be described below, with reference to the drawings in which:

fig. 1 is a plan view of the cassette, the upper face of which is partially cut out;

fig. 2 is a sectional view along line II-II in Fig- i;

fig. 3 is a plan view of the caster comprising the cleaning means;

fig. 4 is a sectional view along the line IV-IV in FIG. 3.

The cassette 10 comprises in a known manner a cleaning tape 11 which unwinds from a supply reel 12 to be wound up on a take-up reel 13.

During its normal running, this strip is in contact with the drive, reading and recording members of the magnetic strip to ensure its cleaning.

According to the invention, on the path of the strip is a roller 20, part of the periphery of which is in contact with the strip 11.

This contact ensures the rotation of the wheel 20 around its axis 21 during the movement of the strip.

The outer periphery of this roller is slightly grooved so that the strip 11 causes it to rotate in a certain manner.

This roller comprises a felt 22 also mounted on the slightly asymmetrical axis 21 so that a slight protuberance 23 passes through a slot 24 formed in the wall 25 of the roller 20.

The casing of the cassette 10 has an opening 30 facing the felt 22 and the roller 20 so as to allow the user to pour cleaning liquid into it. In a preferred embodiment, this orifice comprises a distributor device 31 made up of several passages 32.

When the felt is soaked with the cleaning product, it soaks the strip only on the portion which is applied to its protuberance 23, the rest of the periphery of the roller 20 preventing any contact with the felt.

As the roller 20 is driven in rotation when the strip travels, it impregnates, at each of its rotations, the strip on a sector corresponding to the surface of the protuberance 23 of the felt.

In this way the strip is only soaked periodically.

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that and discontinuous (over the width of the protuberance 23 relative to the perimeter of the caster 20) and no longer adheres to the tape drive drum or to that supporting the magnetic heads.

For example: in a preferred embodiment, the strip is soaked every six centimeters over a width of about eight millimeters.

In the case of a reversible cassette, all the elements necessary for soaking the tape are duplicated, as indicated by 5 the numbers 201, 21 ′ and 231 in FIG. 1.

1 sheet of drawings

Claims (4)

654,136 1. Cleaning cassette comprising a strip the scrolling of which cleans the means for reading, recording and driving a magnetic strip, as well as a source of cleaning liquid, characterized in that the strip (11 ), when it scrolls, causes means (20, 23, 24) by which the liquid is applied from the source to the strip of irne intermittently. 2. Cleaning cassette according to claim 1, characterized in that on the path of the strip is provided a roller (20) of which a part of the periphery is in contact with the strip (11) so as to ensure its rotation and in that on the axis (21) of this caster is also mounted a spongy material (22) which comprises a slight protuberance (23) passing through a slot (24) formed in the wall (25) of the caster (20) so that the strip is only discontinuously soaked on the portion which is applied to the protuberance. 2 3. Cleaning cassette according to claim 2, characterized in that the casing (10) of the cassette comprises means allowing the user to pour cleaning liquid onto the spongy material (22), these means being able to consist of that the housing has an opening (30) facing said material and the roller (20). 4. Cleaning cassette according to claim 3, characterized in that one can provide a distributor device (31) of the liquid on the spongy material.