Magnetic tape cassette arrangements

A cassette system for any type of recording medium in strip or tape form, such as films and magnetic tapes, consists essentially of a housing whose external dimensions match those of a conventional type of cassette, and a protective holder for the recording medium which is wound into at least one roll. The housing and the holder are separate or separable members and can be fitted together. Both are provided with means for inserting the holder into the housing in the correct position, and for introducing the recording medium into the transport apparatus. The housing is provided with opening and closing means. The holder can be designed to be separable from the roll of recording medium. Preferably, the housing is a precision-made article and the holder a low-cost article.

FIELD OF THE INVENTION 
The present invention relates to a cassette for a recording medium in strip 
or tape form, particularly a magnetic tape, consisting of an approximately 
right parallelepipedal housing with openings serving to admit the drive 
members and scanning means on the transport apparatus, the scanning means 
cooperating with the recording medium which is located inside the housing, 
is wound into at least one roll, is guided in the housing by guide means 
and is driven by means of the drive members, and to a cassette housing and 
protective holder for a recording medium wound into at least one roll. 
PRIOR ART 
It is known to use cassettes for recording media in tape form, such as 
films and magnetic tapes for signal storage, in appropriate recording 
and/or playback apparatus. The signals which are to be stored or have been 
stored may be analog or digital signals which contain audio, video, data 
or instrumentation information, or a combination of these. 
A large variety of such tape cassettes is known and in use in the audio, 
video, data processing and instrumentation fields. Some examples of such 
cassettes are briefly described below. 
Compact cassettes have found world-wide acceptance in the audio sector, but 
special forms for data recording and video recording have also been 
disclosed; however, the latter are expensive to manufacture and in most 
cases cannot be mass-produced. 
Compact cassettes, which are an inexpensive type of cassette, have housings 
with relatively large manufacturing tolerances and are therefore lacking 
particularly in respect of their tape guidance characteristics, so that 
regardless of the quality of the magnetic tape in the cartridge, the 
recording/playback quality attainable is poor. 
It is also known from U.S. Pat. No. Re. 29,049 to accommodate virtually all 
of the tape guide means on the apparatus rather than inside the cassette, 
so that the cassette becomes a mere contained for the rolls of tape, the 
tape guide means on the apparatus passing through suitable openings in the 
container to engage the tape and the tape reels, so that very precise tape 
guidance is achieved substantially independently of the cassette housing. 
This type of cassette is equally suitable for recording data, video and 
audio signals and can also be employed with advantage in automatic 
cassette-playing equipment. In cassettes of this type which are currently 
on the market, the housing consists of a plastic, for example polystyrene, 
but contains metal components such as brake members and tape guide rolls 
and is therefore not very economical to manufacture. 
OBJECT OF THE INVENTION 
It is an object of the present invention to provide, on the basis of the 
prior art cassettes, a high-quality cassette for a recording medium, in 
particular a magnetic tape, which offers very precise guidance of the 
recording medium and enables the medium to be exchanged. 
FEATURES AND ADVANTAGES OF THE INVENTION 
We have found that this object is achieved by a cassette for a recording 
medium in strip or tape form, particularly a magnetic tape, consisting of 
an approximately right parallelepipedal housing with openings serving to 
admit the drive members and scanning means on the transport apparatus, the 
scanning means cooperating with the recording medium which is located 
inside the housing, is wound on at least one hub to form a roll (the hub 
and the roll of medium in combination being referred to hereinafter as 
"reel"), is guided in the housing by guide means and is driven by means of 
the drive members, wherein the reel and the housing are separate units, 
which can be brought together for operation, the reel being located, at 
least when outside the housing, in a protective holder which enables the 
reel and the recording medium to be introduced into the housing in the 
correct position, and wherein the housing is provided with opening and 
closing means and with means for inserting the reel and the recording 
medium into it in the correct position. 
In this way, complete interchangeability of the recording medium 
(hereinafter referred to as "tape") is achieved, since the housing and the 
protective holder can be marketed separately. Not only does this offer the 
choice of different tape lengths and of different tape properties 
(photographic or magnetic), but it also permits optimum combination of 
products from different manufacturers, for example in order to achieve 
special audio or video effects or to meet special requirements in data 
signal storage or instrumentation signal storage. 
The invention offers both the amateur and the professional user, in the 
case of all types of signals, an improvement in recording/playback 
quality, and a higher recording density, which in turn facilitates digital 
signal coding and offers greater storage capacity. The protective holder 
is in particular easy for amateurs to handle and is advantageously of a 
form suitable for filing in a library; it is made of a suitable material, 
and has an appropriate shape for protecting the tape adequately from 
external damage. 
The housing is advantageously made of a more rigid material than the 
holder, is also easy to handle, especially for the amateur, and offers 
substantially constant highly accurate tape guidance when used in a 
transport apparatus conjointly with the tape, which is either within the 
protective holder or has been taken out of the latter. 
The housing may include parts which are used on present-day commercial 
transport apparatus; such parts may originate directly from the apparatus 
production. Advantageously, the housing should be able to be mass-produced 
economically. 
When a film is used as the recording medium, either the type of film or the 
sensitivity of the film material or a special contrast or color effect may 
be the criterion dictating an exchange of film. 
In the case of magnetic tape, the type of tape (whether audio tape or video 
tape, etc.), the maximum output level or sensitivity of the magnetic 
material, the mechanical properties, or special measuring and testing 
characteristics, may constitute the criterion dictating a tape exchange. 
Detailed features of the subject of the invention are discussed below. The 
reel or reels is/are at least part of the time accommodated in a 
protective holder, which is preferably flat and closed substantially on 
all sides. 
Such a holder can be produced economically from plastic and/or paper, 
advantageously, in the case of plastics, by thermoforming, injection 
molding or compression molding or, in the case of paper, by other suitable 
mass production methods, for example pressing. The shape of the holder 
should be such as to allow simple and, preferably, automatic fitting of 
the tape into the holder. 
A housing for such a holder, or for the recording medium taken from such a 
holder, may consist of a bottom and a lid which are lockably connected or 
connectable. This permits simple insertion and removal of the protective 
holder or of the recording medium taken therefrom, and ensures completely 
satisfactory operation of the cassette when the housing has been locked. 
Advantageously, the bottom and lid are pivotally connected or connectable, 
the pivotal axis being horizontal or vertical. 
Tape guide means may be provided on the bottom and on the lid, or, more 
particularly, on one of these. 
In a very advantageous embodiment, the tape guide means are provided 
virtually exclusively on the housing. This makes it possible to achieve 
tape guidance of such high precision that even higher recording densities 
with smaller head gap lengths/track widths are readily attainable. 
The tape guide means may be, for example, guide rolls or pins which, 
advantageously, are located near the openings for admitting the scanning 
means. 
Furthermore, in a practical embodiment it is advantageous to provide the 
bottom or lid with means for accommodating and/or guiding the protective 
holder, thereby facilitating insertion of the holder into the housing in a 
predetermined position and/or closure of the housing. 
In another practical embodiment, there are provided locking means for the 
lid and bottom, which ensure that the parts which affect the functioning 
of the cassette are in the correct position. 
In a further embodiment, the protective holder is provided with a 
projection which can be gripped manually from outside the housing; in 
particular, the protective holder can be of a greater width than the 
housing. 
In another embodiment, the protective holder is provided with guide slots 
for the reel(s) and/or for guide means present on the housing. 
The protective holder is advantageously provided with means which enable it 
to be at least partially detached from the reel(s). 
The housing can also be provided with an opening which may or may not be 
closable, for removing and introducing the protective holder. 
Advantageous embodiments of the protective holder and of the housing 
according to the present invention and incorporating the above features 
are described below. 
The protective holder for at least one reel comprises at lease one recess 
of a shape and size corresponding to those of a reel of the maximum 
intended diameter. A protective holder for two reels can also have a 
recess of a size and shape corresponding to those of two reels of half the 
maximum intended diameter. The protective holder is advantageously 
produced from a suitable plastic, such as rigid polyvinyl chloride, and 
consists of one or more thermoformed or injection-molded parts. 
The housing consists, as is conventional, of an approximately right 
parallepipedal hollow body having a bottom and lid, one or both of which 
may have sidewalls, which enclose one or more reels. Drive means, provided 
on the apparatus, drive the reel(s) within the hollow body, so as to 
transport the tape, and scanning members, provided on the apparatus, are 
in contact, or can be brought into contact, with the transported tape, so 
as to effect recording and reproduction of information on and from the 
tape respectively. According to the invention, the bottom and lid are 
movably connected or connectable to one another by connecting means, and 
can be locked together. Furthermore, the connecting means can be removable 
or non-removable and in particular consist of hinge means. 
The housing advantageously consists of a light metal, a light metal alloy 
or polystyrene.

FIG. 1C is a perspective view of a cassette which has standardized 
dimensions and is intended to have the same functions as a conventional 
compact cassette. 
However, in contrast to conventional compact cassettes, the housing 10 is a 
precision-made part which is designed to receive a protective holder 11 
(hereinafter referred to simply as "holder") (FIG. 1B) with two reels. 
The housing 10 (FIGS. 1C and 1B) is preferably made from a material which 
lends itself to mass-production and retains its shape over a wide 
temperature range. The housing 10 consists of two parts, the bottom 12 and 
the lid 13, which in the present case are movably connected by hinges 14. 
The hinges 14 are fixed to the rear wall of the bottom 12 and to the rim 
of the flat lid 13. An embodiment of the holder 11 is shown partially 
inserted into the guide rails 15 on the underside of the lid. After the 
holder 11 has been inserted and the lid 13 has been closed, tape guide 
rolls or projections 16 enter the recesses 17 in the holder 11, over which 
rolls or recesses the tape 18 is tensioned by means of retaining members 
19. Pins or rolls 20 are provided on the holder 11 or 11A, at the outer 
ends of the left-hand and right-hand recesses 17. Advantageously, the 
interior of the holder 11A is sealed off from the outside at these points, 
as shown in FIG. 1A, so as to provide protection against dust and dirt. 
The size and shape of the holder 11, presently being discussed, is 
determined by, for example, the maximum reel diameter if the holder, when 
used in conjunction with the housing 10, is to remain within the latter. 
In this case, the holder 11 may be made from a suitable material in one 
piece or from two firmly connected parts. 
However, if, after insertion in the housing 10, the holder 11 is to be 
partially or completely removed therefrom, for example to ensure, from the 
very beginning, that it does not have an adverse effect on tape guidance, 
the size of the holder may also be determined by the diameter of a 
half-full reel. In this case, at least half of the holder is removable, 
and the two halves of the can be designed to fit together like a box. The 
holderr 11A in FIG. 1A can be provided with a book-like spine 21, which 
may for example be detachable and which has a length corresponding to the 
length of the holder, so that the latter can be stood upright. The spine 
can be designed to be written upon, for filing purposes. 
In a particular embodiment, the holder 11 or 11A consists of two parts 
which may be symmetrical or unsymmetrical with respect to the median plane 
of the holder, though a symmetrical shape greatly facilitates mass 
production. The holder 11 or 11A is advantageously made of a plastics 
material, for example from a sheet of polystyrene, polyethylene or, 
preferably, rigid polyvinyl chloride, the sheet material being optionally 
bonded to paper or cardboard, and the parts of the holder being joined 
together in a suitable manner, for example by welding. The retaining 
members 19 and/or guide pins or axles for guide rolls 20 can be suitably 
attached to one or both parts of the holder, for example by driving them 
into the material. The retaining members 19, guide pins and rolls 20 
should consist of a non-magnectic material which has little tendency to 
build up static charge. During recording and playback, the holder 11, 11A 
is inside the housing 10, and one or more magnetic heads are pressed 
against the unsupported spans of tape over the recesses 17, the 
compressive force determining the wraparound angle on the head. The reels, 
which are within the holder 11 or partially or completely detached from 
the holder 11, are driven by winding spindles on the transport apparatus 
which enter the openings 22 in the hubs. 
In FIGS. 1B and 1C, actuating means 23 for a locking device for the bottom 
12 and lid 13 are shown on a sidewall of the housing. The locking device 
is shown more clearly in FIG. 2C and will be described in more detail 
later. 
FIGS. 2A to 2C show a further embodiment of a holder 24 intended to be 
mass-produced economically, for example by thermoforming, from the 
materials mentioned earlier, and to protect the rolls of tape against dust 
and mechanical damage. The holder 24 is provided with transvern slot 26 
and 27, the latter having arcuate ends 25 which cooperate with the hubs 
and thus fix the reels in the horizontal plane. Slots 26 and 27 can 
cooperate with guide members in the housing 32 when the holder is inserted 
and removed. It is also possible to dispense with slots 27, in which case, 
for example, inwardly pointing projections which engage the central 
openings in the hubs assume the role played by the arcuate ends 25. 
When the tape is fitted in the holder 24, the reels 28 and 29 are inserted 
into the open side of the holder 24 until the reel hubs are fixed, and 
centered, by the arcuate ends 25. The tape 18 can then be placed over tape 
tensioning pins or rolls 30 which are so designed that they can be pivoted 
from the vertical position shown, into a horizontal position or, better 
still, can be swung downwards against the action of a spring. The pivot 
bearings are shown, in FIG. 2B, as blocks 31 for a pivot which is not 
shown. After the tape 18 has been placed over the tape-tensioning pins 30, 
the lower part of the holder, shown in FIG. 2B, can be made up into a 
complete holder by placing an upper part on top of it, or by attaching an 
upper part thereto in a suitable manner, and is then ready for insertion 
into a housing. FIG. 2C shows a housing 32 which has been modified to 
receive the holder 24 and is slightly different from the housing 10 shown 
in FIG. 1B. 
The housing 32 can be produced from a suitable heat-resistant material of 
high mechanical strength, for example from a metal, a metal alloy, a 
plastic, which may or may not be glass fiber-reinforced, or a combination 
of plastic and metal parts. Advantageously, the housing 32 consists of two 
parts 33 and 34 which, like the parts 12 and 13 of the housing 10, are 
connected to one another by horizontal hinges, so that the lid 34 can be 
pivoted into a vertical plane. In contrast to the housing 10, elongated 
tape guide members 35 and 36 are provided, whose length depends on the 
maximum size of the reels and whose height is determined by the inner 
height of the housing 32. FIG. 2C shows the holder 24, in a not yet fully 
inserted position, in guide rails 37 on the lid 34. When the holder has 
been pushed in up to the stop 38 and the lid 34 has been closed, guide 
members 35 and 36 engage the slots 26 in the holder 24 and thus cause the 
latter to be very accurately aligned in the housing 32. As the guide 
members 36 enter the outer slots 26, they actuate the tape-tensioning pins 
30, so that these pivot in the direction shown by the arrows in FIG. 2B. 
The holder 24 can be withdrawn from the housing 32 either by means of a 
projection on the holder, not shown here (but shown in FIG. 3C) or by 
means of the part of the holder which protrudes beyond the plan-view 
contour of the housing 32 (cf. FIG. 3C). 
To enable the holder 24 to be withdrawn at the front of the housing 32, the 
front wall has a longer opening than that of the housing 10. 
It should be noted, at this juncture, that, in contrast to the embodiment 
shown in FIGS. 1A to 1C, the holder 24 is introduced into the guide rails 
37 with its open longitudinal side first, so that it can be readily 
withdrawn from the front of the housing 32. As a result of the design of 
the present embodiment, when the housing is closed the magnetic tape 18 
readily passes over the tape guide means, in the present case elongated 
members 35 and 36; it is of course also possible to use rolls as guide 
means. The pivotable tensioning pins 30 must therefore be appropriately 
arranged in the holder. When the pins 30 have been swung downwards, the 
tape 18 is released from the holder 24 and becomes, if appropriate 
temporarily, part of the housing 32, by means of which the tape can be 
guided very accurately on a conventional cassette recorder. After the 
recording or playback operation is over, it is simple to reinsert the 
holder 24 into the housing 32, release the tape 18 and the reels 28 and 
29, and take the holder with the tape reels out of the housing 32. In the 
course thereof, the tensioning pins or rolls 30 re-assume their vertical 
position so that they lift the tape 18 off the tape guide means on the 
housing 32. 
The specific procedure for removing the reels from the housing is as 
follows: 
The holder 24, with the slots 26 and 27 facing the bottom 33, is inserted 
into the housing 32, with its open longitudinal side first, until the stop 
38 is reached. In the course thereof, the reels 28 and 29 slide into the 
holder 24 and are fixed by engagement of the hubs with the arcuate ends 
25. At this point in time, the tape 18 is already in contact with the 
tensioning pins 30. After operating the locking mechanism, the housing 32 
is opened and the holder 24 containing the reels can be taken out, and, if 
appropriate, filed. 
In addition to the arcuate ends 25, other parts of the walls of the holder 
24 may be in contact with the reels; for example the large walls of the 
holder may be domed inwards toward the reels 28 and 29 like the liners in 
a compact cassette for example. In a practical embodiment, it is of course 
also possible, in order to protect the tape, to design the slots 26 and 27 
as embossed grooves which project inwards and function as ridges which 
guide the reels. Such embossed grooves 26 then need only have openings in 
the region of the tensioning pins 30, so that the pins can be pivoted 
downwards by parts on the housing passing through these openings. In 
principle, the slots or grooves can also be replaced by parallel ribs on 
the inner surface of the holder, in which case openings are again 
necessary. 
Locking means of the housing 32 are shown in FIG. 2C. A movable spring 
member 39 is attached at one end to one or both sidewalls and carries an 
inwardly projecting stud 40 and an actuating button 23 which passes 
through a slot 41 in the side wall of the housing, and can be operated 
from the outside by finger pressure. An opening 42 to receive the stud 40 
is provided in one or both guide rails 37. 
Depression of the button(s) 23 from the outside moves the spring member(s) 
39 inwards, thus enabling the stud(s) 40 to engage the opening(s) 42. 
Locking is effected by releasing the button(s) 23. Unlocking is effected 
by depressing the button(s), thus disengaging the stud(s) 40 from the 
opening(s) 42. 
A third embodiment of a holder 43 is shown in FIGS. 3A to 3C and is 
intended for use in conjunction with a housing 44, whose lid 45 can be 
pivoted in a horizontal plane abut a vertical hinge 46. Essentially, the 
holder 43 and housing 44 correspond to those described earlier, with the 
following differences. 
The hinge 46 consists of a pivot 47 and a bushing 48, with an axial locking 
spring 46 (cf. FIG. 3b). The rear edge of the lid 45 of the housing has a 
hinged flap 50, which is advantageously pretensioned in the closing 
direction, and which once again permits the use of a holder 43 which can 
be withdrawn from the housing. To enable the holder to be withdrawn 
manually, it either has a suitable projection 51 or is wider than the 
housing. By pulling on the projection 51 or on the protruding part of the 
holder, the holder 43 can be withdrawn backwards from the housing 44 and 
the hinged flap 50 closes automatically. The reels are at this stage ready 
for operation in the housing 44, the tape 18 being guided, on either side 
of the tape pressure pad 58, by tape guide members 56 and guide rolls 57. 
The holder 43 is inserted from above into the bottom 64 of the housing 44, 
the tape 18 spanning an elongate recess 52 in the holder 43, into which 
recess the tape guide means on the housing 44 project. Retaining means for 
the tape 18 are provided in the front corners of the holder 43, so that 
the tape cannot slip into the interior of the holder 43, which would make 
insertion into the housing 44 an involved procedure. 
The retaining means, here in the form of stubs 53 and 54 attached to the 
lower and upper part respectively, must be so designed and arranged, in 
order to permit withdrawal of the holder 43 from the housing, that the 
tape 18 can slip therebetween. Re-insertion of the reels into the holder 
43 is in this case only possible after the housing 44 has been opened, the 
lower part of the holder has been inserted, and the upper part of the 
holdr has been placed on top. 
The holder 43 is advantageously closed on five sides, and the reels leave 
the holder 43 through the opening 55, which adjoins the slot 52, when the 
holder is withdrawn. Advantageously, the holder 43 is designed like a box, 
so that it can be parted, for example, symmetrically in its median plane. 
FIG. 4 shows a further embodiment of a holder 59. This constitutes an 
example of a box-like holder referred to above. A lower part 60 has a 
shape corresponding to that of two reels 61 and 62 each carrying about 
half the total length of tape, so that both reels can easily be clamped 
between the sidewalls of the lower part 60 and are thus retained in a 
manner which prevents them from slipping about. Such a holder can be 
designed to accommodate just one reel, as can the above-described holder 
embodiments. 
The upper part 63 fits exactly over the lower part 60, advantageously 
giving a tight seal, so that the reels 61 and 62 are stored in a dustproof 
manner and safe from damage. After removing the upper part 63, the reels 
61 and 62, together with the lower part 60, can be inserted into a part of 
an appropriately designed housing, which part is preferably already on the 
apparatus, so that the winding spindles pass through the openings in the 
housing into the housing interior; the central openings in the hubs 
immediately come into engagement with the winding spindles when the lower 
part 60 containing the reels is placed in position, and the lower part 60 
of the holder 59 can than be pulled off carefully. Before starting the 
transport apparatus, all there remains to do is to place the span of tape 
18, extending between the two reels, over the tape guide means on the 
apparatus or on the housing, by hand or with an auxiliary tool, such as a 
pair of tweezers, and to close the housing or the apparatus. 
In principle it is also possible to leave one of the parts of the holder in 
the housing or transport apparatus and only remove the other part. In this 
case, the part of the holder which remains in the housing or apparatus 
must possess openings for the admission of guide and drive means. In order 
to keep out dust when such a holder is closed, the openings must be 
suitably covered. 
The holder 59 can be produced from a suitable plastic as an extremely 
simple thermoformed article, like a blister-pack container for example.