Storage system for supports such as containers for audio and video cassettes and discs

A housing has an opening for receiving supports for audio or video cassettes or discs. When the support is fully inserted in the housing, an elastic bias member in the housing exerts a force on the support in a direction which is substantially transverse to the insertion direction. The elastic bias member yields in response to manual pressure on the support which turns the support through an angle in a first rotational direction to a pivoted position. When the support is in its pivoted position, the elastic bias member moves the support to an ejection position while rotating the support in a second rotational direction which is opposite to the first rotational direction. A plurality of housing modules with such elastic bias members are connected together by snap connectors for storing a plurality of supports for recording media.

The present invention refers to a housing for storing a recording support 
such as a magnetic tape cassette, laser disc or the like, and preferably 
to a housing module of this type so formed as to permit modules to be 
stacked on top of each other as well as to be connected laterally so as to 
provide a multi module store for cassettes and the like. 
For the purpose of the present specification the word "cassette" will be 
used in a broad sense to include conventional cassettes on their own, 
cassettes in their protecting containers, laser disc containers and so on. 
Naturally, magnetic tape cassettes include both audio and video cassettes. 
DESCRIPTION OF THE RELATED ART 
Many types of housings for cassettes are known, usually for use in 
automobiles. In this latter case, they are normally designed to receive 
the cassettes without their standardized protecting containers whereby 
they have to provide a certain guarantee against the entry of dust and 
resistance to fibres and other external influences. Such housings 
basically comprise a hollow brick shaped body having at least one larger 
area panel corresponding to the top or bottom of the housing and three 
narrow upstanding walls fixed to the panel, two parallel side walls 
defining an opening for the insertion/ejection of the cassette. 
Many such housings are provided with a drawer which may enter or exit the 
housing through the insertion/ejection opening. The magnetic tape cassette 
is received in the drawer without its protective container. The drawer is 
under the influence of a metal spring or complex ejection mechanism which 
may be actuated by a trigger such as a button for automatic opening of the 
drawer to give the user access to the cassette. These housings are of 
extremely complex construction in terms of manufacturing techniques since 
they require complicated ejection systems comprising various parts that 
have to be mounted inside or alongside the housing itself. Apart from 
this, they are expensive since to the cost of the components one has to 
add high production costs due to the essential minimum manufacturing 
tolerances. 
Housings having means for connection to each other are also known in the 
art but they generally have the following disadvantages: 
known housing systems are designed only for use in the home or only for use 
in an automobile; 
housing systems are known which only serve for a given type of cassette, 
for example, magnetic tapes or laser discs, and they cannot be coupled to 
other housing combinations for other cassette types, such as video 
cassettes, for forming a comprehensive store. This is an obvious problem 
in view of the growing diversity of types of cassettes presently available 
on the market; 
known housings of the same type that may be coupled to each other have to 
have coupling elements on the large surface areas and such elements are 
usually formed to provide dovetail type connections which means that such 
surfaces have to be of considerable thickness and that they have to be 
relatively thick to permit the connection which is effected by insertion 
until the correct alignment configuration is reached. Consequently, these 
housings can only be connected in the direction of their width and height 
and cannot be accommodated in bigger spaces such as on a shelf or in a 
cupboard; 
the known housings also fail to permit one easily to identify the programme 
or contents of the cassettes contained therein since they are stored 
without their protective containers which have to be kept elsewhere or 
even thrown away. This represents an unjustifiable waste since the 
protective containers obviously represent part of the total cost of the 
cassette. 
OS DE 2742348, for example, discusses a combination of a programme 
identification label together with the housing. The disadvantage of this 
system is that the labels cannot be seen after various cassettes have been 
piled on top of each other. 
OS DE 3202204 discloses an example of a special cassette container which is 
different from the standard container. Up to a certain point it may be 
piled, and has an identification arrangement similar to that of the 
standardized container but it does not combine with other existing systems 
due to its different dimensions and it cannot be used with other types of 
cassettes. 
OS DE 2427103 and OS DE 2719783 refer to coupleable housings from which the 
cassettes may be withdrawn after opening the front cover. Both systems are 
expensive from a manufacturing point of view and piling is limited. 
Furthermore, the standardized cassette container once more cannot be used 
with the result that there is no programme identification. 
U.S. Pat. No. 4,549,775 discloses a housing for cassettes and the like 
arranged for partial rotation of the cassette about a pivot point at the 
back of the housing. A parallel ejection spring is actuated on pressing 
inwardly one corner of the cassette. When the cassette is fully inserted 
in the housing the spring applies a transverse force against the cassette 
to press it against an opposite side of the housing to maintain it in 
place. On pressing the opposite front corner of the cassette inwardly, the 
cassette pivots or rotates about the pivot point until a corner thereof 
passes in front of the spring which then increases the rotational force 
applied by the finger and ejects the cassette. This system involves a 
continuous rotational or tilting movement of the cassette that is 
initiated with finger pressure and, as tilting increases, completed by the 
force of the spring. If ejection of the cassette is attempted merely by 
pressing in the cassette to initiate the titling movement and only one 
hand is used, the spring produces a catapult effect and there is a danger 
of the cassette being ejected and falling on the ground. 
In view of the above, the large majority of existing housings present the 
above mentioned disadvantages which are often greater than the advantages 
they offer. 
An object of the present invention is to provide a housing of the above 
type having a much simpler and secure insertion/ejection mechanism than 
traditional systems. Preferably the simultaneous formation of a store for 
different types of presently commercialized cassettes is permitted and the 
housing is adapted for use both in the home and in vehicles as well as 
being suitable in commerce as a display. 
In addition the housing of this invention has an extremely reduced 
manufacturing cost due to its simplicity even though it may meet 
requirements regarding protection against dust and vibrations when used in 
vehicles, and it may also permit visual identification of its contents. 
It is also an object of the invention to provide a housing module which 
eliminates the disadvantages of known housings in that it may be coupled 
to other modules in a simple manner so as to facilitate the formation by 
the user of a comprehensive file. Due to its varying possibilities of the 
arrangement of the housing compartments of different modules, it permits 
one to make the best possible use of the space available. 
SUMMARY OF THE INVENTION 
According to the present invention a housing for storing a recording 
support such as a magnetic tape cassette, laser disc or the like, having 
an opening for the insertion and ejection of said support and defining an 
insertion direction, a pivot point for said support within said housing 
and opposite said opening and first elastic bias means arranged in said 
housing on a first side of said opening, which apply to said support, when 
fully inserted in said housing, a force substantially transverse to said 
insertion direction and towards the opposite side of said opening and, 
when manual pressure in the insertion direction is applied to said support 
at a point adjacent to said opposite side of said opening, said support is 
pivoted against the bias of said first elastic bias means in a first 
rotational direction to an ejection position in which said first elastic 
bias means apply to said support a force having a component in an ejection 
direction opposite said insertion direction, is characterized in that said 
first elastic bias means has a configuration such that, when said support 
reaches said ejection position, said ejection force tends to rotate said 
support in a second rotational direction opposite said first rotational 
direction. 
Preferably, the above mentioned elastic bias means comprises a spring fixed 
to said housing at said first side of said opening and including a spring 
blade portion directed substantially in said insertion direction, said 
spring blade portion having a free end provided with a protuberance 
adapted to cooperate behind said support when in said ejection position to 
provide said force component in the ejection direction. 
The spring blade may be advantageously formed as an integral part of the 
housing, the whole being able to be a single part moulded from plastic 
material. This greatly reduces the final costs. 
The fact that, in the preferred embodiments, special steel springs and 
drawers are not necessary is an obvious advantage as regards manufacturing 
simplicity and costs. Metal springs are difficult to mount. Compared with 
traditional systems both material and labour costs are drastically 
reduced. 
In contrast to known housings in which the cassette is introduced without 
its protective container, the housing of the present invention-may be 
adapted to receive the cassette together with its container. This 
automatically simplifies or facilitates identification of the programme of 
the cassette by the user since the longitudinal narrow face of the 
standard cassette container always carries an indication of the programme 
and this will always be visible through the insertion/ejection opening of 
the housing. 
The housing of the present invention preferably comprises a module 
attachable to another similar module, said module comprising a panel of 
larger area and upstanding therefrom, first and second side walls and a 
back wall contiguous with first ends of said side walls, said module being 
a single part of moulded plastics material and further being formed with 
first means for permitting connection to a similar module, the panel of 
said similar module serving to complete a cavity for receiving said 
container defined by said two panels, said first and second side walls and 
said back walls. In addition, the module may be provided with second means 
for permitting lateral connection to similar modules. The embodiments 
described later and illustrated in the accompanying drawings show 
preferred and advantageous intermodule connecting arrangements. 
The housing modules according to the preferred embodiment of the present 
invention may be coupled in any desired direction, in particular taking 
advantage of the depth of the available space. Furthermore, housing 
modules may be coupled in side to side relation with other housing modules 
for different types of cassettes. Piling is possible both along the 
shorter and longer edges, that is to say, with the cassettes standing up 
or lying down so that cassette manufacturer recommendations may be 
respected. Thus, housing modules for video cassette containers may be 
grouped together and coupled to different sized modules for other 
cassettes, laser discs and so on.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, FIGS. 1 to 3 show first embodiment of a 
housing module according to the invention. It consists basically of a 
hollow substantially brick shaped open box having a large area panel 1, a 
side wall 2, a double side wall 3 and a longitudinal double back wall 4. 
Walls 2, 3 and 4 are upstanding or normal to panel 1. Walls 2 and 3 are 
substantially parallel to each other and to a cassette insertion direction 
indicated by the arrow in FIG. 2. Wall 3, however, is thinned at its end 
remote from back wall 4 to form a ramp, the point where the ramp commences 
defining a cassette pivot point 5' so that the cassette insertion/ejection 
opening defined between the free ends of side walls 2 and 3 is slightly 
wider than the distance of the parallel portions of these walls. 
Back wall 4 is also narrowed to form a ramp 6 at its end that meets side 
wall 3, ramp 6 being inclined backwardly away from the cassette 
insertion/ejection opening. The point where ramp 6 meets the rest of wall 
4 defines another cassette pivot point 6'. Ramps 5 and 6 are substantially 
at an angle of 909 with respect to each other. 
Integrally moulded with the free end of side wall 2 is a spring element 7 
in the form of a blade which projects backwardly in a direction generally 
parallel to wall 2 but is curved away therefrom and terminates in a 
rounded inwardly directed protuburence 8. Side walls 2 and 3 are provided 
with lateral coupling means in the form of a cavity 9 in double wall 3, 
approximately centrally thereof, having a relatively narrow opening and 
expanding to a planar bottom portion in wall 3. Side wall 2 is 
correspondingly formed with coupling means in the form of two hook shaped 
projections 10 which are inclined outwardly away from each other at an 
angle that corresponds to the inclination of the side walls of cavity 9. 
The hook portions of projections 10 are planar and are aligned with each 
other for abutment against the bottom of cavity 9 of a second module being 
coupled thereto. Furthermore, the free end of wall 2 adjacent to the 
cassette opening is formed with a front flange portion 25 in a plane 
slightly displaced from the plane that contains the free end of wall 3 and 
consequently ramp 5. This free end of wall 3 is formed with a small cavity 
26' which co-operates with a small protuberance 26 on flange 25 of an 
adjoining module when coupling is effected. 
The complete module is preferably moulded as a single part of plastics 
material and it will be understood that due to the elasticity of 
projections 10 and flange 25 two modules may be snap fitted to each other. 
Vertical coupling between modules may be effected due to second coupling or 
connection means in the form of pins 11 which are moulded integrally with 
or separately from the rest of the module and are distributed at various 
points along walls 2, 3 and 4. In the case being described there are five 
coupling pins 11, two of which are positioned at the junctions of walls 2 
and 3 with back wall 4 so as to ensure stability of the pile when various 
modules are stacked onto each other. 
As can be seen from FIGS. 5 and 6, panel 1 is formed with holes aligned 
with coupling pins 11, such holes being defined by cylindrical portions 13 
having lengths corresponding to the heights of walls 2, 3 and 4. The lower 
end of each cylindrical portion 13 is provided with or has fixed thereto 
pins 11. Orifices 12 and the inner bore of cylindrical portions 14 have a 
diameter suitable for receiving the coupling pins 11 of another module 
(see FIG. 8). 
Pins 11 are hollow and are longitudinally split by slots 14 along part of 
their length. A stop means or protuberance 14' is formed between each pair 
of slots 14 for co-operation with the inner surface of a corresponding 
cylindrical portion 13 of another module. 
FIGS. 7 to 9 show the vertical stacking procedure in which coupling pins 11 
of one module are compressed as they pass through orifices 12 in the 
module immediately therebelow, the edge of each orifice 12 being slightly 
rounded to facilitate insertion. The resiliency of the cylindrical wall of 
pins 11 provided by longitudinal slots 14 permits the pin to be compressed 
and to expand as indicated by the arrows in FIG. 7 so that the pin may 
penetrate the cylindrical portion 13 under compression due to the stop 
means 14', as shown in FIG. 8, until they reach slots 15 in the 
cylindrical portion 13. This alleviates the compression imposed by stop 
means 14' and permits radial expansion of coupling pin 11 with the stop 
means 14' penetrating the slots 15 with a characteristic click to indicate 
to the user that the desired coupling shown in FIG. 9 has been completed. 
Obviously stop means 14' and slots 15 could be by other means to fix pins 
11 in cylindrical portions 13. 
As can be seen particularly from FIG. 5, when stacking one module on to 
another, the large area panel 1 of the lower module will form the base for 
the upper module so as to complete the definition of the cassette 
insertion/ejection opening. Panel 1 can be provided with moulded ribs on 
its upper face, directed in the insertion direction, so as to reduce 
sliding friction when a cassette is inserted or rejected. 
FIGS. 10, 11 and 12 show a base 16 suitable for mounting or fixing a first 
lower-most housing module. The base is in the form of a rectangular block 
which corresponds to the size of the module to be placed therein. It is 
formed with a longitudinal passage 17 running along its complete length as 
well as with a series of parallel and uniformly spaced transverse ribs 18 
which serve to reduce friction on insertion of a cassette into the 
lower-most module. Base 16 is also formed with a cavity 17' corresponding 
to cavities 9 in the housing modules. The upper face of base 16 is formed 
with cylindrical holes 19 for co-operation with the coupling pins 11 of 
the housing module to be mounted thereon. 
In order to fix base 16 to a separate surface, for example, a shelf or the 
bottom of any given compartment, a fixing rail 20 is provided. The rail 
has a bottom surface 21 and two longitudinal walls 22 arranged 
perpendicularly thereto so as to fit precisely into passage 17 of base 16. 
Rail 20 may be fixed to the support surface by means of an adhesive tape 
or the like or, as illustrated, it may have holes 24 distributed along its 
length so that it may be fixed to the surface by nails or screws. 
Reinforcement ribs 23" are also provided between longitudinal walls 22. 
Rail 20 may be moulded from plastics material to have a narrowed end 24' 
so as to be received between longitudinal walls 24 at the other end of a 
further rail section. This permits the addition of further bases when 
increasing the store. 
The longitudinal walls of rails 20 may also be formed with channels grooves 
23 at given intervals along their lengths, as can be seen in FIGS. 18 and 
19. Such grooves serve to weaken the rail which may then be broken to 
adapt its length to that of a compartment, for example, as shown in FIG. 
30. 
FIG. 20 shows how two piles of housing modules for different types of 
cassettes may be coupled together. Two bases 16 are shown to be placed 
over a fixing rail 20, each base having mounted thereon a respective pile 
of housing modules according to the invention. The left hand base 16 is 
specifically for video tapes whereas the right hand base carries housings 
for standard music cassettes. Although the cassette containers for the two 
types are of different sizes, the respective housing modules are provided 
with identical coupling means (cavities 9 and projections 10) so that 
lateral coupling may be effected. It will also be seen that 
notwithstanding the compact storage system, the indications of the 
contents of the cassette containers are readily visible. 
Although the two piles are shown separately, they may be slid towards each 
other along rail 20 to effect the snap coupling action between cavities 9 
and projections 10. Naturally such coupling can also be effected in the 
absence of rail 20. 
FIG. 21 shows more clearly how flange 25 formed beside the cassette opening 
serves as a means for supporting and reinforcing coupling between adjacent 
housing modules. As already mentioned, with respect to FIG. 2, 
protuberance 26 on flange 25 snap fits into corresponding reentrance 26' 
at the free end of ramp 5 of the next module. 
FIG. 22 shows how various housing modules may be arranged in a drawer with 
the cassette insertion/ejection openings upwardly so as to permit the user 
to identify the contents of facing the cassettes rapidly, particularly 
because the cassettes themselves are in their protective containers 
clearly showing the identity of their contents. 
FIG. 23 shows how a pile of modules may be arranged vertically on the 
fixing rail 20 with rail 20 co-operating with cavities 9. Another pile of 
modules containing other types of cassettes may also be positioned on the 
rail next to the first pile. The manner in which the first pile is guided 
on the rail is shown in FIG. 24. With further reference to FIG. 23, it 
will be seen that flanges 25 of the modules are provided with labels which 
are preferably self adhesive, which may be used to carry codes, such as 
letters, numbers, symbols, colours and the like, related to the contents 
of the tapes. 
FIG. 26 shows that various combinations or associations of housing modules 
according to this invention are possible using a single moulded part. One 
such possibility is illustrated in the figure. It comprises the 
association of two modules to form a single housing module that may be 
moulded as a single part simply on a large scale production line. 
FIGS. 27, 28 and 29 also show piles of housing modules coupled in side by 
side relation, clearly illustrating that both housing modules may carry 
the same identification by means of adhesive labels, following the 
principle that is facilitated by the present invention of determining that 
each cassette has its own place in the store of housing modules. In this 
manner one can immediately identify a given tape in a position 
corresponding to the same type of music as also one can immediately see if 
a tape is missing. The base could also be provided with an identification 
determining groups of cassettes belonging to the same specific area. Also, 
the arrangement permits the cassette to be used in a different location 
from that of the housings, for example, in an automobile, without losing 
control of its existence. 
FIG. 30 shows the possibility of storing various piles of housing types or 
even types of cassette simultaneously, for example, video and sound tapes, 
laser disc containers as well as any combinations thereof, advantage being 
taken of the full depth of a compartment, such as, for example, a shelf in 
a cupboard. 
FIGS. 31 to 34 show the manner of inserting and ejecting a cassette into 
and from a housing according to the invention. 
FIG. 31 shows initial insertion into the housing of, for example, a 
cassette that may or not be within its protective container. As will 
immediately be seen, the cassette should be introduced perpendicularly to 
the insertion/ejection opening, the parallel parts of the inner faces of 
walls 2 and 3 serving as a guide. As the cassette continues to be 
inserted, spring element 7 is deflected gradually to a state of maximum 
deflection until the end protuberance 8 abuts the side of the cassette and 
forces it to the right in the direction of the arrow shown in FIG. 32 
against opposite side wall 3. In this manner the cassette is snugly and 
firmly held in the housing. 
When the user wishes to withdraw the cassette, he should apply a light 
pressure to the side of the cassette nearest to ramp 5, as indicated by 
the thumb shown in FIG. 33. The cassette is then tilted about the two 
pivot points 5' and 6' at the higher ends of ramps 5 and 6, the 
corresponding wall portions of the cassette lying along those ramps. When 
this occurs, and as may be seen in FIGS. 33 and 34, the inner left hand 
corner of the cassette moves forward and the rounded protuberance 8 at the 
end of spring element 7 snaps around that corner of the cassette and 
provides it with a force having a component in an ejection direction as 
may be seen from FIG. 34. The result is partial ejection of the cassette 
which reaches the configuration shown in FIG. 34. The cassette may then be 
removed manually. 
FIG. 36 shows another configuration for the elastic element 7 which in this 
case is a separate moulded part having a thickened base formed with two 
parallel holes 27 designed to receive two mounting pins 28 formed on panel 
1 of the housing module. Alternatively the base of spring element 7 may be 
fixed by ultrasound, adhesive or the like. 
Another possibility is shown in FIG. 37 where spring element 7 is formed as 
part of the flange 25 of the earlier embodiments, the inner surface of 
flange 25 being formed with two parallel closely spaced flanges 29 normal 
to flange 25 and adapted for receiving the free end of the wall 2 of the 
housing module. 
FIG. 39 shows the spring portion of spring element 7 provided with an 
additional elastic element 7' extending backwardly from rounded 
protuberance 8 in the general direction of side wall 2. 
FIG. 40 shows how, on introduction of a cassette, the additional spring 
element 7' is also compressed so as to increase both the ejection force 
and the force applied by element 7 to maintain the cassette in the 
housing. 
FIG. 41 shows how housing modules according to the present invention may be 
used in an automobile. The figure shows that, after ejection of the 
cassette container, the latter is already in the correct or suitable 
position for withdrawing the cassette from within its protecting 
container. In the position shown, this operation of withdrawing the 
cassette from its container may be done with a single hand, there being no 
temptation for the motorist to take his other hand off the steering wheel. 
FIGS. 42 to 47 illustrate two further embodiments of the invention which 
incorporate a number of extra and alternative features of an advantageous 
nature, these including an alternative means of simpler manufacture for 
the lateral coupling of modules to each other and an arrangement for 
better preventing accidental ejection of the cassette containers due to 
violent trepidation of a vehicle. 
In each of the embodiments the formations 9 and 10 shown in FIGS. 1 to 41 
are substituted on one side of the module by a simpler cavity 9a formed by 
two vertical parallel ribs 30 terminating externally in rounded 
protuberances 31 narrowing the opening to the cavity and, on the other 
side of the module, a pair of similar ribs 32 that are slightly less 
spaced apart, also terminating in rounded protuberances 33. When joining 
two modules laterally, protuberances 33 of one module are simply snapped 
passed the protuberances 31 of the other module to Obtain the desired 
coupling. 
Considering now more specifically the embodiment of FIGS. 42 to 44, it will 
be seen that the housing module shown therein is provided at its back wall 
with a further spring element comprising two blade parts 34 and 35 
extending to each side of the central cylindrical portion 13 forming part 
of the coupling means of the housing. Both spring element parts 34 and 35 
are curved forwardly whereby, on insertion of a cassette, they will both 
apply a force thereto in an ejection direction. 
Notwithstanding the above, spring element parts 34 and 35 do not eject the 
cassette under normal conditions in view of the presence of two ridges 36 
and 37 adjacent the cassette insertion opening and formed along the top 
front edge of panel 1. Naturally in the housing module shown in FIGS. 32 
to 34 the ridges 36 and 37 behind which the cassette lies and against 
which it is biased by spring element parts 34 and 35, are those formed on 
panel 1 of the module immediately below since that is the panel that forms 
the bottom surface of the housing module illustrated. 
In addition to the above,panel 1 of the same module is formed with U-shaped 
slits 38 as shown in FIG. 42 to define downwardly displaced spring blades 
39. These spring blades 39 maintain any cassette fully inserted into the 
housing biased downwardly against the bottom surface of the housing, that 
is to say, the top panel 1 of the housing module panel 1. This ensures 
that the force of spring element parts 34 and 35 impels the cassette 
against ridges 36 and 37. This provides a positive impediment to the 
cassette being ejected by accident due to trepidation of the vehicle in 
which the housing may be mounted. 
As will be seen from FIG. 43 the outer ends of ridges 36 and 37 are 
inclined cam surfaces. Consequently when the cassette is to be rejected by 
applying finger pressure as shown in FIG. 34, the front left hand corner 
of the cassette rides up the cam surface of ridge 36 which lifts the 
cassette against the bias force of springs 38, permitting it to be ejected 
not only by the force of spring element 7, but also by that of spring 
element parts 34 and 35. 
FIGS. 45, 46 and 47 show an arrangement somewhat similar and equivalent to 
that of FIGS. 42 to 44. In this case half of the back wall 4 is as shown 
in FIG. 1 but, starting at the central coupling cylinder portion 13 the 
inner part of the wall is substituted by a spring element part 35 
identical to part 35 of FIG. 42. 
In addition the present embodiment has the springs 39 and the ridges 36 and 
37 of the previous embodiment substituted by a single spring and cassette 
blocking element 40 which is formed by two slits 41 in top panel 1 of the 
housing. In addition, as seen in FIG. 46, the spring element 40 is 
provided with a front downwardly extending catch portion 42. When a 
cassette is inserted into the housing module, spring element 40 lifts 
slightly to permit its passage but when the position of total insertion is 
attained, the front edge of the cassette will be positioned slightly 
behind catch element 42 which will then fall with the spring to block the 
cassette in the housing. 
Catch element 42 is formed laterally with cam faces in a manner somewhat 
similar to ridges 36 and 37 of the FIG. 42 to 44 embodiment. As a result, 
when withdrawal of the cassette is attempted using thumb pressure as shown 
in FIG. 47, the cassette will pivot and, as this happens, its front edge 
will ride along the left hand cam surface of catch element 42, causing it 
and spring 40 to rise which permits normal ejection of the cassette. 
The right side (as seen in FIG. 47) of cam surface of catch 42 may be used 
to assist raising of the spring 40 when a cassette is being introduced 
into the housing module.