LU81216A1 - CASSETTE FOR ENDLESS MAGNETIC TAPE - Google Patents

Description

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Patent application for ....... 2.5, .197.9 .................

Designation of the Inventor O The undersigned ................. Ernest Meyers, ing. cons. in own. ind ........................

46, rue du Cimetière, Luxembourg acting as - the depositor's agent - (2) the company: TECOSA S.A., 14, rue Aldringen, Luxembourg (3) of the invention concerning:

Cassette for endless magnetic tape designated as inventor (s): 1. Name and first names ........ Pierre. Eggermpnt .......................................... ....... .......................................

Address .............................. Residence ..Sol andor .. .No 6, .Sispony-Lamassana, ... Andorra - 2. Last and first names ........................................... .................................................. .................................................. ..

Address ................................................. ........................ .......................... .................................................. ....................

3. Surname and first names ............................................. .................................................. .................................................. .............

Address ................................................. .................................................. .......... ........................................ ..................................

He asserts the sincerity of the above indications and declares to assume full responsibility for them.

... Luxembourg ........................ .., on, 2. 5.1.97.9 ....... 19 .......

.. r (signature) A 680 25__ (1) Last name, first names, firm, address.

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i PATENT OF INVENTION

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Cassette for endless nagnstiçue tape i f C The Company known as CECCSL S.x.

1-1 rue -.1 dringen I * Lu>: s ~ xourg: i; _ 1 „

The present invention relates to a cassette for an endless magnetic tape comprising a housing, at least two winding rollers intended to permanently hold several winding windings of the strip, this housing being provided on its main faces with openings. with a view to the penetration of the drive and positioning members of a cassette player, known per se, and, on one of its main sections, of lateral openings for the exposure of a section with linear movement of the strip, during its path between the inner turn 10 and the outer turn in view of the cooperation with a reading member and a drive member constituted by a capstan associated with a pressure roller, said openings in the S * faces and on the edge of the housing being provided at a lateral section of the housing, separated from the interior thereof 15 except for a narrow slot for the exit of the strip and an orifice entry for penetration tration of the strip in the housing, this outlet slot and the inlet orifice being arranged substantially on either side of the section with linear movement of the magnetic strip.

A cassette of this kind is described in the French addition certificate Ko 7432S7S. This type of cassette is specially intended for devices with repeated reading such as automatic telephone answering machine, device playing music or an uninterrupted waiting signal, cassette player serving as a guide, etc. Although this type of cassette is increasingly used today, its field of application is nevertheless not comparable to that of conventional cassettes, or universal cassettes, the manufacture of which has been standardized and which can, from this in fact, be manufactured at a relatively low cost price. Consequently, it is essential for the manufacturer of endless tape cassettes to be able to use the so-called standard cassettes and to be able to adapt them to the endless magnetic tape system with the minimum of transformations since the design of a cassette 35 specially adapted for endless belts has a significant impact on their cost price due to their relatively limited scope. It is precisely the merit of the French addition certificate 7432S79 to have made standard cassettes accessible to magnetic tapes! endless ticks.

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The length of the endless magnetic tape is very short compared to the tape length of standard cassettes.

Their length corresponds to a maximum reading time of approximately two minutes with a scrolling speed of 4.75 cm / sec-5 sec. The reason is first of all that for the type of application envisaged for this type of cassette, it is generally not necessary to have a playing time of more than two minutes. Another reason is of a technical nature and comes from the difficulty of ensuring correct operation for an endless belt 10 where the inner turn is connected to the outer turn. Besides, one of the conditions for a correct scrolling of such a type of strip to be possible, at least for a reasonable time, is that the strip is sufficiently loose over its entire length, that is to say that the different winding turns 15 are not tightened as, for example, in standard cassettes. This is of course only possible if the number of spi-I res is not too high, that is to say if the magnetic strip! is not too long. This loosening of the turns and of the band j | moreover poses the most serious problems with a view to correct scrolling of the strip. Indeed, what happens most often is that the game, or what has in one binds the nmou ”of the band, accumulates: 1 mule in a certain place by the formation of a loop, this i | at the expense of a tightening occurring elsewhere. Such excessive "slack" I or loop generally forms just downstream of the carriage or in the region of crossover of the strip with the bundle 1 'of turns, while tightening occurs at the level of the turns.

I Such irregularities in the tension of the belt quickly lead to what is called "weeping" and gradually brings about! complete blocking of the scrolling system. This problem has not been able to be resolved completely by the use of I - magnetic tapes graphitized on their non-sensitive face. In summary, we can say that at the present time there are no cases - i | ! at . sstte for endless magnetic band yes does not have one and / or the other of the drawbacks described above. Consequently, the aim of the present invention is to complete this gap, said: to provide a cassette of the kind described in the preamble, for the manufacture of which one can use the standard elements of crassiguss cassettes and yes allows a challenge - | reasonably correct for a reasonable time.

. .hy- "· For this purpose, a cassette of the kind described in the preamble is essentially characterized by a guide drawn up from the edge between the main faces of the housing, along the winding turns of the strip, the height of this guide being , at least, equal to the width of the ribbon so as to allow crossing between the turns and the strand coming from the inner turn by lifting the latter above the pack of turns, by a separating finger intended to direct the said strand towards the guide and by the fact that the width of said inlet orifice is substantially equal to its height.

10 It is possible to make, at the level of the guide, a recess: in the wall of the housing in order to avoid jamming of the strip between the guide and the housing.

1 The turns of the magnetic strip are preferably formed around a main roller and two secondary rollers. This main roller is driven by means of a friction clutch existing on all cassette recording devices. .

This roller also has a certain play with respect to its drive axis, which contributes favorably to the automatic loosening of the turns. The large width of the entry orifice of the strip 20 in the housing, compared to the relatively narrow slots conventional cassettes allow rapid absorption of a loop that can still form immediately after the capstan.

Other particularities and characteristics will emerge from the detailed description of an advantageous embodiment presented below, by way of nonlimiting example, with reference to the figures in which: FIG. 1 is a schematic plan view of a cassette according to the present invention; FIG. 2 is a view, on an enlarged scale, in section along the line II-II of FIG. 1.

"Figure 1 shows a schematic view of the interior of a hull case, generally designated by the reference 1.This cassette 1 comprises a housing 2 inside which is a principle roller; 3 and two rollers The main roller 3 corresponds to one of the rollers of a standard cassette or universal cassette, while the second roller of such a cassette has been removed from the cassette according to the present invention. can. the two main walls after the removal of this second roller can be plugged, for example, by means of a small tube. The roller 40 has a crenellated bore intended to cooperate with an axis of entrain j n & n & nt 6 ce l ' cassette player in which the 11 :.

| cassette is intended to be inserted. This training axis 1. comprises, conventionally, a friction clutch not shown. The auxiliary rollers 4 and 5 can easily be installed in a ;; 5 housing normally designed for a standard cassette.

The housing 2 also comprises, like the standard cassettes, on the front side, two rollers 12 and 13.Lr.tre these two rollers 12 and 13 'is provided a series of openings 10 intended for the penetration of the drive members and positioning of the device of lec-10 ture, one of these openings represented by the reference S being '·.

intended to receive the capstan. The case also includes a _ y 1 series of openings 11 on its front edge for the exposure of. the magnetic strip, in particular to a pressure roller represented by 9 and one or more reading members not shown. A wall '16 15 separates the region provided with these openings from the rest of the interior of the housing 2. This wall 16 is covered ur.e narrow slot 15 and a relatively wide opening 14 ..-. With the exception of the width of this opening 14, this front cover of the housing provided with the various openings is completely identical to standard cassettes, 2î in which, however, the opening 14 is constituted by a slot identical to the slot 15 this presents. cassette 1.

A magnetic strip shown because the reference 7 is wound in several concentric turns of spirals around the roller 3 and these auxiliary rollers 4 and 5. The strand from the inner turn 25 of the winding is connected to the outer turn through the rollers 12 and 13 between which is located the rectilinear section of ex-position of the magnetic strip. In the example shown, the strip. magnetic 7 scrolls in the direction of the arrow at., that is to say that the inner coil feeds the outer coil of the winding.

30 In order to be able to pass from the inner turn to the outer turn, the magnetic strip ccit francoir the package this turns, which is done, according to the present invention, thanks to the presence of a guide 17 erected this song on one pri: citâtes faces of the housing 2 between the roller 5 and the roller 3. The height of this guide 17 is at least equal to the width of the magnetic strip 7, so as to lift the latter

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the wall of the housing 2 cpposed è that on which the guide 17 is welded, a recess 18 elongated and oriented substantially in the cirec-i hold of the magnetic strip to avoid jamming thereof C, \ ___ between the guide 17 and the wall of the housing 2.

To ensure that the crossing of the bundle of turns by the outgoing strand occurs well at the level of the guide 17 and not, for example, left or right of it, a guide can be provided, the height of which at both ends is greater than that of the central region or a guide having on the coast which is crossed by the hair emerging from a rim or a kind of "tab" at each of its ends.

A separating finger 19 separates the magnetic strip 7 from the last turn of the winding and directs it at the outlet of the roller 3 in the direction of the guide 17 and of the roller 12. The purpose of this finger 19 is to prevent the strip to adhere to the last turn and thus form a loop by driving in the direction of the roller 4.

The conventional cassettes comprise, at the level of the rollers 15 tes corresponding to the rollers 12 and 13 of FIG. 1, bosses represented by 2D and 21 in FIG. 1. The cassette i furthermore comprises a series of additional bosses represented by 22, 23, 24, 25 and 26. These bosses 22, 23, 24, 25 and 26 are formed in the upper wall of the housing 2 and consist, as shown in FIG. 20, of 2, in a kind of protuberance serving as a limit of travel towards the top of the magnetic strip upstream of each of the rollers 3, 4,5, 12 and 13.

The edge of the magnetic strip opposite these bosses slides on a graphite sheet 27 (FIG. 2) provided for this purpose in the bottom of the case.

When the cassette 1 is in the operative position in a reading device, the drive of the magnetic tape 7 is effected, in a conventional manner, by a capstan penetrating through the opening 8 and associated with the pressure roller 9.La magnetic strip 30 tick 7 is slightly pinched by this roller 9 against the cabe-stan in order to prevent any friction and to ensure a movement S. t constant linearity of the magnetic strip 7. This drive of strip 7 is assisted by the rotation of the axis 6 associated with a clutch not shown. The speed of rotation of the axis 6 is such that the tangential speed at the level of the roller 3 is, at least, equal and, in general, slightly greater than the linear speed of the magnetic bd-iôe 7 at the level of the caoestan 8. In other words, it is a friction drive to ensure the winding of ld nanae in the countryside and as it is debited by the capstan 8. iû * .-- a uresence d »Τ 1 inr \ - = \ r = rîi = s -7 -.-, ν ~ i_____ i ·

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excessively strong, which could cause the strip to break.

In the case of an endless magnetic strip, a problem results from the fact that the magnetic strip is driven at constant linear speed by the capstan 8, that is to say that the speed of the outgoing strand delivered by the inner turn and the speed of the re-entering strand brr.art the outer turn is equal insofar as we only hold coir.ote only movement, communicated by the caoestan 6.Or, at the level of the roller 3.1a linear speed of the turn inside cannot be equal to the linear speed of the outside water turn 1q se of their different winding diameter. The difference between the * · linear speed of the inside turn and that of the outside turn is of course d 'All the more granae as the package of turns is thicker, hence the advantage of providing a reduced number of turns.

Because of this problem, the system can only work if the strip is not, as explained above, tight on all its laws because otherwise the coil in L-Oir î eure, pulled by the capstan, h would cause progressive tightening of the package of turns until | system crash, even when using graphite tape, that is! 20 ie lubricated. However, even an endless maanetic tape, ί ·; ji not tight, can parade this satisfying way only if one || manages to maintain a uniform distribution of slack over the entire length of the strip. The cassette according to the invention has more! several technical features which ensure this uniform distribution of slack over the length of the strip.

The presence of the two auxiliary rollers 4 and 5 ensures, in association with the roller 3, a rational and relatively longer path, which makes it possible to have a reduced number of turns for a given length of the magnetic strip.

According to another particularity, the roller 3 has a certain p clearance with respect to the axis 6, on the one hand and with respect to the housing I: on the other hand, which causes, during rotation, a slight variation and I just miss which tends to loosen the turns around the gallet, so as to ensure a kind of self-regulation of the fricti i 35 of the turns.

I The crossing between the turns and the strand emerging from the inner turn constitutes one of the delicate points for all types of tape cassette without rxn. In the embodiment, the strand issuing from the inner coil undergoes a first twist of 40 -Ό maximum and a second twist, in the? Nvsrse direction. before * 7 11 engaged around the roller 12. The slack of this section located between the roller 12 and the roller 3 causes a more or less floating movement of the strip and means that the two successive twists are generally less than 90 °. Therefore, the magnetic strip 7 does not rub over its entire non-sensitive graphite face on the guide but only on its lower edge. The recess 18 also allows the strip 7 to pass the guide 17 with a certain inclination relative to the latter.

It should be noted that the guide 17 as well as the recess 18 can be reversed with respect to the embodiment shown in FIG. 1, so that the magnetic strip, instead of passing over the bundle of turns, pass below.

The separating finger 19 prevents the formation of a loop in the direction of the roller 4, as a result of excessive momentary slack between the roller 12 and the roller 3. This can in particular occur during the manufacture of the cassette and the winding. initial magnetic strip, when the slack is not yet evenly distributed over the entire length of the path.

Another important feature of the cassette according to the invention is the relatively large opening of the orifice 14 through which the magnetic strip again enters the interior of the case 2. In fact, it has been found that , as a result of the adhesion between the strip and the pressure roller 9, in particular due to static electricity, the magnetic strip tends to follow the rotation of this roller and form a loop developing outside the housing. 2. If, instead of a relatively wide opening, there was only one slot similar to slot 15, as in standard cassettes, such a loop, once formed, could only be absorbed with sorting. On the contrary, in general, there is therefore a fold in the magnetic strip before penetration into the slot, c, which causes the blocking of the strip. The formation of such a fold • most often takes place during the passage of the section of the strip where the two ends are welded together and where the strip is consequently less flexible. On the other hand, the width of the opening lr 35 considerably reduces the risk of the formation of such a fold and the jamming of the magnetic strip. If a loop occurs nevertheless downstream of the capstan c, it would be quickly absorbed because the traction exerted by the pressure of the roller 3.

i ** · 1 "" \ ____! I * i 'These different teennieuas particularities allow meine li to use a non-graphitized magnetic tape for a cassette i of short duration, for example 30 seconds, for which seven ί | turns of winding around the rollers 3, 4 and 5 is sufficient, j 5 It should finally be pointed out that the casing 2 of the cassette |> is a casing identical to the casing of standard cassettes fa ll.bricked in large series, so that the use of 'Such a standard housing considerably reduces the cost price of an I: cassette for an endless belt according to the present invention. There is therefore no need for a special mold either. cial for manufacturing the cassette case.

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Claims (3)

1. Cassette for an endless magnetic tape comprising a housing, at least two winding rollers intended to permanently maintain several turns in the winding of the strip, this housing being provided on its main faces with openings for the penetration of the drive members and this positioning of a cassette player, known per se, and, on one of its main edges, of lateral openings for the exposure of a section with linear movement of the tape , during this w 10 its path between the inner turn and the outer turn for cooperation with a reading member and a drive member constituted by a capstan associated with a pressure roller, said openings in the faces and on the edge of the casing being provided at a lateral section of the casing, separated from the interior thereof, with the exception of a narrow slot for the exit of the strip and an inlet orifice for the penetration of the strip into the housing er, this slot this outlet and the inlet orifice being arranged substantially on either side of the section with linear movement of the magnetic strip, 2G characterized by a straight edge guide between the main faces of the housing, along winding turns of the strip, the height of this guide being, at least, equal to the width of the ribbon • so as to allow crossing between the turns and the strand coming from the inner turn by lifting the latter at above 25 of the package of turns, by a separating finger intended to direct said strand towards the guide and by the fact that the width of said inlet orifice is substantially equal to its height. 2. Cassette according to claim 1, characterized by a main roller and two auxiliary rollers for the formation * 30 of a winding turn. I 3. - Cassette according to claim 2, cai'actisée in * that the main roller has a crenellated bore into which penetrates, when the cassette is in the operative position in a reading device, a drive shaft provided with a friction clutch 35, and in that the main galeuain has a certain clearance with respect to this axis and with respect to the casing of the cassette. 4. Cassette according to claim 1, characterized oar an elongated recess provided in the inner face of the housing! face of the cruid and oriented substantially in the direction of the nas- 3. Cassette according to claim 1, characterized by these bosses p ^ evu ^ Cans at least one of the walls of the casing upstream | âe each of the rollers. - jt, · λ j> \ a * j ί