Cassette tape recorder

The cassette tape recorder for the four common types of cassettes according to German Industrial Standards DIN 32 715 T, 32 715 W, and the so-called micro-cassette as well as the mini-M-cassette comprises three sound head carriers (10, 20, 30) adapted to be moved selectively into operating position. Furthermore, the spacing between winding shafts (2,2') is adjustable by a movable cam disc (17). This adjustment is taken care of by cam disc engaging fixtures (23, 33) at the movable sound head carriers (20 and 30, respectively) and by a spring (18) holding the cam disc (17) in an inoperative position against a stop. Likewise provided are adjustable winding heads (3,3') causing different engagement members (4,6) to become effective for the winding drive, the adjustment of the winding heads (3,3') also being effected upon moving of the sound head carriers (10,20,30). Scanning members serve to scan a geometric dimension of the cassette and based on that scanning the spacing of the winding shafts (2,2'), the position of one of the sound heads (14,35,60) and, if desired, adjustment of the winding heads (3,3') and their engagement members (4,6) are determined.

FIELD OF THE INVENTION 
The instant invention relates to a cassette tape recorder, comprising two 
winding shafts movably disposed at variable spacing and each including 
engaging fixtures for winding drums of the casssettes, further comprising 
at least one electromagnetic sound head disposed at a predetermined 
position with respect to the winding shafts 
BACKGROUND OF THE INVENTION 
The invention deals with the problem of different types of sound recording 
tape cassettes being available which are not compatible. In the field of 
dictating machines alone four different types of cassettes have become 
common lately. They are: 
1. the so-called Grundig cassette according to German Industrial Standard 
DIN 32 750 T, 
2. the mini-cassette according to DIN 32 750 W, 
3. the micro-cassette, and 
4. the mini-M-cassette. 
These cassettes differ in many respects. Their dimensions are different as 
well as their reel cores, the spacing between cores, and the centering 
means, and finally also the provision of "scanning windows" for sound, 
playback, and erasing heads. As a result of these differences the various 
cassettes can be used only in tape recorders designed specifically for 
their employment. Once a user has decided to adopt a certain system, he 
will be bound to continue to make use of it unless he is willing to 
replace the whole system, putting up with the economic loss involved. 
In greater firms or clerical offices different systems are bound to clash, 
and then dictating and playback sets must be available for each system. 
That is uneconomical. DE-OS No. 32 34 584 discloses a cassette tape 
recorder which includes two winding shafts arranged at variable spacing 
for adaptation to different cassettes. The winding shafts are guided by 
arcuate slots formed in a plate which receives the cassettes and are 
displaced along the path defined by these slots. Before any change of the 
type of cassette the proper spacing must be adjusted between the winding 
shafts, a cumbersome affair for unskilled users. If they forget to make 
the adjustment, the cassettes or the tape recorder may become damaged. 
SUMMARY OF THE INVENTION 
It is, therefore, an object of the instant invention to provide a cassette 
tape recorder of the kind specified initially which will adapt 
automatically to different types of cassettes. 
This object is met, in accordance with the invention, in that the at least 
one sound head is movable between given limit positions, in that a 
scanning member is provided to scan a geometric dimension of the 
respective cassette, and in that the mutual spacing of the winding shafts 
and the position of the at least one sound head are variable in response 
to this scanning. 
Advantageous modifications and further developments of the invention may be 
gathered from the subclaims. 
The tape recorder according to the invention also is easy to handle because 
all that needs to be done is to insert the cassette. Thereupon all other 
driving and scanning conditions become adjusted automatically in response 
to the respective width of the cassette. 
The apparatus according to the invention substantially must fulfill the 
following functions: 
1. It must be possible to adjust different axial spacings for the cassette 
drives (winding shafts). This is obtained in supporting the winding shafts 
so as to be displaceable (pivotable) and to be adjusted to the respective 
axial spacing required by means of a control cam. 
2. To be able to drive different winding cores by a single shaft, the 
latter is so designed that its diameter corresponds to the smallest 
cassettes and that engaging fixtures are provided at the circumference for 
mini-cassettes. The shaft has excess length so that an engaging fixture 
for the other two types of cassettes may be placed on the upper part 
thereof, this engaging fixture including the equipment of the 
mini-cassette cores at its inside or being approximated to the same. The 
respective arrangement needed for a certain cassette then may be entered 
into engagement by mutual displacement of the winding shaft and of the 
winding head in longitudinal direction. In a preferred embodiment this is 
effected by a cam-controlled rocker which displaces the winding shaft and 
the winding head with respect to each other 
3. The scanning members (recording, playback, and, if desired, erasing 
heads) are to be adapted to the respective types of cassettes as well as 
any possible arresting means for the cassettes. A preferred embodiment, 
therefore, comprises three sound head carriers which are pivoted into 
operating position, as required.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Throughout the figures like reference numerals designate like parts. 
For the sake of clarity the drawing shows only the essential functioning 
members to the extent that they are needed to understand the respective 
figure. 
The cassette tape recorder shown in FIGS. 1 to 3 comprises a base plate 1 
serving as the carrier of the entire tape recorder. The tape recorder 
comprises two winding shafts 2, 2' which are spaced from each other and 
adapted to be driven by an electric motor (not shown) and (rubber) drive 
belts by way of a belt pulley each 16 and 16', respectively. At their ends 
the winding shafts carry displaceable or reversible winding heads 3, 3' 
which in the present case each include three engaging pins 4 uniformly 
distributed along the circumference and projecting vertically upwardly 
from a carrier 5 or 5', respectively, to enter into engagement with 
corresponding projections or webs provided at the winding drum of the tape 
cassette. The carrier 5 or 5' is supported for axial displacement on the 
winding shaft 2 or 2' and secured for rotation by a groove and tongue 
joint 6 (cf. FIG. 5C). The groove and tongue joint 6 at the same time 
serves to carry along the winding drum of tape cassettes of different 
structure. The adjustment in height of the carrier 5 is effected by means 
of a displaceable engaging plate 7 or 7' which slides along a guide pin 8 
or 8' secured to a stationary carrier plate 9. The guide pins 8 and 8', 
respectively, at the same time serve as pivot axes of the winding shafts 2 
and 2', respectively, whereby their mutual spacing is variable. 
The tape recorder comprises three separate sound head carriers 10, 20, and 
30 of which only a respective one will perform duty. They may change their 
relative position with respect to the winding shafts 2 and 2', a change 
which is effected by pivoting motion in the embodiment shown. 
FIG. 1 shows the sound head carrier 10 in operating position, while the 
sound head carriers 20 and 30 are swung outwardly and thus not ready for 
service. The sound head carrier 10 is pivotable about a pivot axis 11 
which extends parallel to the base plate 1. To this end the sound carrier 
10 is fixed by two lateral carrier arms 12 to pivot bearings at the base 
plate 1 (pivot axis 11). The carrier arms 12 are engaged by tension 
springs 13 which pull the sound head carrier 10 into its upwardly swung 
operating position. The other ends of the tension springs 13 are kept 
stationary. 
Here the sound head carrier 10 carries a sound head 14 which here is fixed 
to the sound head carrier 10 by means of supporting legs 15. 
In the embodiment shown FIG. 1 represents the operating position for the 
so-called Grundig cassette according to German Industrial Standard DIN 32 
750 T. The sound head 14 accordingly is a so-called "AWL" head, a head for 
recording, playback, and erasing. 
The winding mandrel used in the cassette mentioned is a cup which carries 
the winding on the outside and comprises a hub at the inside including 
three spokes or webs. The engaging pins 4 and 4' thus serve for the 
rotational drive of this cassette so that the winding head 3 or 3' is in 
its raised position (cf. FIG. 5A) at which the pins 4 and 4' extend beyond 
the winding shafts 2 and 2'. 
The other two sound head carriers 20 and 30 are fixed to vertically upright 
pivot axes 21 and 31, respectively, on the base plate 1 and may be pivoted 
into operating position, if required. Preferably this is done by an 
electric motor drive. 
As explained in greater detail with reference to FIGS. 2 and 3, the 
following must be carried out when the sound head carriers 20 and 30 are 
swung into position: 
The sound head carrier 10 must be pivoted out of the way and this is 
effected by engaging fixtures 22 or 32 projecting vertically downwardly 
from the sound head carriers 20 and 30 and abutting against the front edge 
of the sound head carrier 10 oriented toward the winding shafts. 
Furthermore, the axial spacing of the winding shafts must be changed. To 
this end the winding shafts 2 and 2' are positively guided at a cam disc 
17 (cf. FIG. 6) and this cam disc is adjusted by cam disc engaging 
fixtures 23 and 33 which are coupled to the sound head carriers 20 and 30, 
respectively. The cam disc 17 is biased in one direction by a tension 
spring 18 such that the cam disc 17 will be in a position as required for 
the operating position upon use of the sound head carrier 10 in order to 
establish the spacing between the winding shafts 2 and 2' needed with this 
operative position. In the embodiment shown the cam disc engaging fixture 
33 serves as stop for the cam disc 17 when the sound head carrier 30 is in 
the outwardly pivoted position. 
Finally, also the winding head 3 or 3' and/or the winding shaft 2 or 2' 
also must be displaced, if required. In the embodiment shown this is 
effected only when the sound head carrier 30 is used and, therefore, it 
will be described in greater detail with reference to FIGS. 3 and 5. It 
should merely be mentioned here that the adjustment of the winding heads 3 
and 3' or of the winding shafts 2 and 2' is carried out by a rocker 40 
tiltable about an axis 48 which extends parallel to the base plate 1 and 
is supported in two bearing columns 41 and 42 fixed on the base plate 1 
The rocker 40 or a scanning tongue 43 of the rocker 40 slides along a 
shift cam 44 disposed vertically with respect to the base plate 1 and 
fixed on a rotary plate 45 which is coupled positively with the sound head 
carrier 30 and, therefore, follows the rotation of the latter whereby the 
shift cam 44 is adjusted. The rocker 40 furthermore is biased by a tension 
spring 46 into a position at which the engaging pins 4 project beyond the 
upper end of the winding shaft 2, namely the position shown in FIG. 5A. 
For adjusting the mutual spacing between the winding shafts 2 and 2', the 
cam disc 17 is guided, on the one hand, in bearings 50 and 50', 
respectively, which are retained by the winding shafts 2 and 2', 
respectively. These bearings 50 and 50' are formed with guide grooves in 
which the cam disc 17 is guided. The bearings 50 and 50' are axially 
movable with respect to the winding shafts 2 and 2'; and the winding 
shafts may rotate freely with respect to these bearings. In addition the 
cam disc 17 is supported at the upper end of a post 51 which carries a 
support plate 52 at its upper end for permanent support of the bottom side 
of the cam disc 17. One end of the tension spring 18 also is secured to 
the post 51. 
As may be taken from FIG. 1A, the positive coupling between the sound head 
carrier 30 and the rotary plate 45 carrying the cam disc engaging fixture 
33 for the cam disc 17 and the shift cam 44 for the rocker 40 includes 
"lost motion" obtained by an arcuate oblong hole 47 in cooperation with a 
coupling rod 34. The coupling rod 34 is connected firmly to the sound head 
carrier 30, while its lower end is guided in the oblong hole 47. When the 
sound head carrier 30 is pivoted inwardly from its backwardly swung 
position (FIG. 1A), the coupling rod 34 will not take along the rotary 
plate 45 whose fulcrum also is the pivot axis 31 until the coupling rod 34 
has travelled all along the oblong hole 47. 
With the sound head carrier 20 adjustment of the rocker 40 is not required, 
instead the rocker position is needed as determined by the spring 46. 
Therefore, only the cam disc 17 must be adjusted upon pivoting of the 
sound head carrier 20. To this end an engaging plate 24 is fixed on the 
pivot axis 21 approximately at the level of the cam disc 17 and coupled 
rigidly to the sound head carrier 20 by way of the engaging fixture 22. 
The cam disc engaging fixture 23 which will then displace the cam disc 17 
is mounted to the bottom side of the engaging plate 24. As may be taken 
from the top plan view of FIG. 1A, the front edge of the engaging plate 24 
connecting the engaging fixture 22 with the cam disc engaging fixture 23 
is oblique (inclination 25). This serves the purpose of permitting the 
front edge of the sound head carrier 10 to pass the engaging plate 24 when 
the sound head carrier 20 is pivoted into position, involving the positive 
outward pivoting of the sound head carrier 10. 
Reference is now made to FIG. 2 showing the sound head carrier 20 pivoted 
into position, the sound head carrier 10 being left out for purposes of 
clarity. 
The sound head carrier 20 has been swung around the pivot axis 21 thus 
having moved the engaging plate 24 by way of the engaging fixture 22. This 
has caused the cam disc engaging fixture 23 to come to a stop at the cam 
disc 17 pressing the latter against the force of the spring 18 (FIG. 1A) 
into the position shown in FIG. 2A. Hereby the winding shafts 2 and 2' 
were forced to move toward each other, the engaging plates 7 and 7' being 
pivoted about the guide pins 8 and 8', respectively. The winding heads 3 
and 3' with the engaging pins 4 and 4', on the other hand, have not 
changed their relative positions with respect to the winding shafts 
because the rocker 40 was not actuated. 
Pivoting of the sound head carrier 20 here is effected by means of an 
electric motor 26 the driven shaft of which is connected to a lug formed 
at the sound head carrier 20 or the engaging plate 24 by means of two 
articulated connecting rods. As indicated by the two arrows at the 
connecting rod 28,the direction of rotation of the electric motor 26 is 
reversed for pivoting of the sound head carrier 20 into and out of its 
operating position. The position in space of the electric motor 26 with 
respect to the point of engagement of the connecting rod 29 at the sound 
head carrier 20 is so selected that the two connecting rods 28 and 29 will 
have a toggle lever effect in the range of the limit position. In this 
manner it is assured that the sound head carrier 20 is pressed into its 
operating position under a sufficiently strong force, the operating 
position being reached by a stop between the front end of the sound head 
carrier 20, i.e. the end remote from the pivot axis 21, and the pivot axis 
31. 
As already explained with reference to FIG. 1, the engaging fixture 22 
takes along the sound head carrier 10 when the sound head carrier 20 is 
pivoted from the inoperative position (FIG. 1A) into the operative 
position (FIG. 2A), pivoting the sound head carrier 10 about the pivot 
axis 11 and thus out of its operative position against the force of the 
springs 13. 
In the case of the embodiment shown,the operating position illustrated in 
FIG. 2 is suitable for the so-called microcassette. With this cassette the 
winding mandrel is a ring which carries the winding on the outside and has 
six dogs at the inside formed along the diameter. A recording and playback 
head 60 as well as an erasing head 61 are provided for this cassette. 
These two heads 60 and 61 are fixed on a carrier plate 62 which in turn is 
fixed on the sound head carrier 20 by means of a threaded pin 63 so as to 
move together with the same. 
In addition two vertically upwardly protruding restraining pins 64 and 65 
are fixed on the sound head carrier 20 to enter into corresponding 
openings of the micro-cassette. 
Consequently the cassette must be pushed from above on the two restraining 
pins 64 and 65. 
When the sound head carrier 20 is pivoted back from its operative position 
shown in FIG. 2A into its inoperative position (FIG. 1A) by the electric 
motor 26, the sound head carrier 10 is swung back by the springs 13 
because the engaging fixture 22 releases the sound head carrier 10 when 
the sound head carrier 20 is swung back. A toggle lever effect between the 
two connecting rods 28 and 29 also is established in the inoperative pivot 
position of the sound head carrier 20 so that again a sufficiently strong 
force is available in order to move the sound head carrier 20 into an 
exactly defined limit position. 
FIG. 3 shows the third operating position at which the sound head carrier 
30 comes into effect. This third operating position is suitable for the 
so-called mini-cassette and the so-called mini-M-cassette. Both types of 
cassette differ only in the dimensions of length and width but not in 
respect of the spacing and design of the winding cores or as regards the 
position of the sound head. Also with these cassettes the winding mandrel 
is a ring which carries the winding on the outside and has six dogs at the 
inside protruding from the diameter. The inner diameter of this ring, 
however, is smaller than that of the micro-cassette. Furthermore, the 
spacing between the winding shafts of the mini-cassette and of the 
mini-M-cassettes is somewhat greater than in the case of the 
micro-cassette which has the smallest distance between winding shafts of 
all marketable cassettes. 
Also with these cassettes again the sound head 35 (recording and playback 
head) as well as the erasing head 36 are arranged separately. Finally, 
these mini-cassettes also have recesses at their bottom side by means of 
which the cassette is held in cooperation with restraining pins 37 and 38. 
The two heads 35 and 36 and the restraining pins 37 and 38, therefore, are 
fixed on the sound head carrier 30 at a corresponding relationship with 
respect to each other. Also this sound head carrier 30 is moved by an 
electric motor 53, again by way of two articulated connecting rods 54 and 
55 one of which is secured to a lug 56 of the sound head carrier 30, while 
the other one is fixed to the driven shaft of the electric motor 53. The 
two connecting rods 54 and 55 are interconnected by a joint 57. The 
arrangement of the articulated connecting rods and the motor again is so 
selected that a toggle lever effect is obtained in both limit positions. 
When the sound head carrier 30 is moved from the position shown in FIG. 1 
into the operating position according to FIG. 3, first the downwardly 
projecting engaging fixture 32 mounted firmly on the sound head carrier 30 
will contact the sound head carrier 10, pivoting the same out of the way. 
Upon further pivoting motion the coupling rod 34 firmly connected to the 
sound head carrier 30 travels through the arcuate oblong hole 47 until it 
comes to a stop at the end thereof and then takes along the rotary plate 
45 upon further movement. This rotary plate 45 rests on the base plate 1 
and its axis of rotation also is the pivot axis 31. Movement of the rotary 
plate 45 on the one hand moves the cam disc engaging fixture 33 and, on 
the other hand, the shift cam 44 which projects vertically from the rotary 
plate 45. The cam disc engaging fixture 33 displaces the cam disc 17, 
whereby the mutual spacing of the winding shafts is reduced. 
The shift cam 44 tilts the rocker 40 by having a tongue 66 of the rocker 40 
slide upwardly along the vertical inclined face 67 of the shift cam. In 
this manner the rocker 40 is tilted against the force of the spring 46 so 
that the winding shaft 2 is displaced upwardly while the winding head 3, 
at the same time, is displaced downwardly. Hereby only the winding shaft 2 
with the groove and tongue joint 6 is effective for the winding drive of 
the cassette, while the engaging pins 4 at the winding head 3 are 
ineffective. 
When the sound head carrier 30 again is pivoted out of its operating 
position, the tongue 66 will slide down along the inclined face 67, and 
the rocker 40 again is tilted by the spring 46 into the other position 
shown in FIGS. 1 and 2. During this return pivoting motion of the sound 
head carrier 30 the sound head carrier 10 again is swung upwardly by the 
springs 13. 
Reference now will be made to FIG. 5 showing the support of the winding 
shaft 2 and the adjusting mechanism of the winding shaft and of the 
winding head 3. 
At its upper end the vertical upright post 51 on the base plate 1 carries a 
spacing and guiding sleeve 70 to the upper and lower ends of which 
supporting plates 71 and 72 are fixed which extend parallel to the 
engaging plate 7. The guide pin 8 presenting an extension of the post 51 
passes through the upper supporting plate 71 and constitutes a pivot 
bearing and, at the same time, a guide means for parallel displacement of 
the engaging plate 7. The sleeve 70 is not displaceable in axial direction 
of the post 51, but it may be pivoted about the common axis of the post 51 
and of the guide pin 8, taking along the three plates 7, 71, and 72. 
The two supporting plates 71 and 72 extend so as to be superposed over the 
belt pulley 16 and each support a pivot bearing 76 and 77 in which the 
winding shaft 2 is journalled. Of course, the belt pulley 16 is firmly 
connected for rotation together with the winding shaft 2, for example by 
the groove and tongue joint 6. The carrier plate 9 (cf. FIGS. 1 to 3) also 
is disposed between the two plates 7 and 70 and the guide pin 8 extends 
through a bore formed in this carrier plate 9. The lower pivot bearing 77 
is formed with a circular groove in which the cam disc 17 is guided. 
A slide pin 73 extending parallel to the post 51 is also guided in the 
spacing and guiding sleeve 70. This slide pin 73 consequently is axially 
displaceable and extends from the bottom to the top through the supporting 
plate 72, the sleeve 70, the supporting plate 71 up to the engaging plate 
7 to which it is connected in a centering aperture. A collar 74 resting on 
the rocker 40 is provided at the lower end of the slide pin 73. A collar 
75 also is provided at the lower end of the winding shaft 2 and engages 
the other end of the rocker 40. 
The spring 46 (FIG. 1B) has the effect that the rocker moves the slide pin 
73 upwardly into the position shown in FIG. 5A. The slide pin 73 thereby 
pushes the engaging plate 7 in upward direction and the latter in turn 
presses the winding head 3 upwardly. For this purpose the engaging plate 7 
is guided in a circular groove 69 formed at the outer periphery of the 
winding head 3. At this position of the rocker simultaneously the winding 
shaft 2 is lowered into its lower position. 
At the other pivot position of the rocker 40 (FIG. 5B), on the other hand, 
the slide pin 73 is lowered and thus also the engaging plate 7 and the 
winding head 3, whereas the winding shaft 2 is pressed upwardly. It may 
also be recognized that the winding shaft 2 is axially displaceable with 
respect to the belt pulley 16. 
Upon adjustment of the mutual spacing of the winding shafts 2 and 2' the 
latter, in the final analysis,are pivoted about the guide pin 8. Hereby, 
however, the distance of the winding shaft from the drive motor (not 
shown) or a driven plate (likewise not shown) is changed only so minutely 
that the (rubber) belt hereby practically is not elongated noticeably. 
FIG. 6 shows a variant of the cam disc 17. It consists of a flat plate 
having two cutouts 79 and 80 which extend in mirror symmetry with respect 
to its central axis 78. The winding shaft 2 or, more specifically, the 
groove formed in the bearing 77 is guided along these cutouts. Starting 
from the outside and towards the inside the two cutouts 79 and 80 approach 
each other so that displacement of the cam disc 17 in the direction of the 
arrow 81 will move the two winding shafts 2 and 2' away from each other. 
In the area between the two cutouts 79 and 80 the cam disc 17 is formed 
with a bore 82 in which the spring 18 (FIG. 1A) is fastened. The spring 
pulls the cam disc 17 in the direction of the arrow 81. 
Recesses 83 and 84 of different depths are formed in the cam disc 17 at the 
side remote from the open ends of the cutouts 79 and 80. The deepest 
location of these recesses 83 and 84 is of semicircular shape and engaged 
by the cam disc engaging fixtures 23 and 33, respectively. The cam disc 
engaging fixtures 23 and 33 act in a direction opposite to the elastic 
force of the spring 18 so that the cam disc 17 then is displaced contrary 
to the direction of the arrow 81, whereby the winding shafts are moved 
towards each other. 
FIG. 7 is a more detailed illustration of the rocker 40 and the shift cam 
44. The shift cam 44 is fixed on the rotary plate 45. It has two 
vertically upwardly projecting portions, one horizontal portion 68 and one 
contiguous rising portion having the inclined face 67. The rocker 40 is so 
arranged above the shift cam 44 that its lower edge or a scanning tongue 
(43 in FIG. 8) rests on the upwardly directed face of the shift cam 44. 
With the rocker 40 in the pivot position shown in FIG. 7A which 
corresponds to the pivot position shown in FIGS. 1, 2, and 5A, the lower 
edge of the rocker rests on the horizontal portion 68. The spring 46 not 
shown in FIG. 7 pulls the end of the rocker not resting on the shift cam 
in upward direction. If the rotary plate 45 is rotated about the pivot 
axis 31, the inclined face 67 will contact the bottom side and the rocker 
40 tilts about the axis 48 into the position shown in FIGS. 7C and 7D. 
In the embodiment according to FIG. 7 the rocker is U-shaped in cross 
section, having two vertically upwardly oriented legs 85 and 86. These 
legs are engaged respectively by the collars 74 and 75 (cf. FIG. 5). 
FIG. 8 is a top plan view and a sectional view along line VIII--VIII of 
another variant of a rocker 40 as shown for FIGS. 1 to 3. The rocker 
includes three pairs of arms 87, 88; 89, 90 disposed in mirror symmetry 
with respect to the rocker axis 48 and a scanning tongue 43 as well as an 
arm 49 disposed between the same. The spring 46 is fastened to a bore 96 
formed in the latter. Here all these arms lie in one plane. Vertically 
upwardly projecting legs 91, 92, 93, 94 are mounted on the arms 87, 88, 
89, and 90, and these legs are in contact respectively with the collar 74 
or 75 of the two winding drives. A tubular bearing 95 is mounted on the 
rocker 40, for instance, by brazing. This bearing presents the pivot 
bearing of the rocker. As far as clarity permits, those parts of the 
rocker which are to be seen in FIGS. 1 to 3 are provided with the 
reference numerals according to FIG. 8. 
FIG. 4 shows the scanning means for the cassettes. This scanning means 
preferably is located in a housing cover 100 which has a rectangular 
recess 101 disposed above the winding shafts and the sound head carriers. 
Two scanning rails 102 and 103 extending parallel to each other and each 
having an inclined face 104 or 105 at its one end are received in this 
recess. Each scanning rail 102 and 103 is connected, preferably 
integrally, to a planar plate portion 106 and 107, respectively. The 
scanning rails 102 and 103 comprise guide sleeves 108 and 109 which extend 
transversely of their longitudinal extension and through which a guide rod 
110 is passed. The guide rod is journalled at both ends of the recess 101 
in bearings 111 and 112. The two scanning rails 102 and 103 and the 
associated plate portions 106 and 107, respectively, are interconnected by 
a parallelogram linkage 113, 114, and 115. 
A pivotable switch contact arm 116 is supported on the guide rod 110 at the 
plate portion 106 and has its one leg 117 pass through the plate portion 
106, while the opposite leg carries a contactor 118. A total of four 
electrical contacts 119, 120, 121, and 122 are arranged at the link 114 of 
the parallelogram linkage extending in parallel with the guide rod 110. 
The link 115 of the parallelogram linkage extending substantially parallel 
to the scanning rails 102 and 103 includes a projecting extension 123 
serving as a positive guide of a contact pressure arm 124 which is 
pivotably held in a pivot bearing 125. 
The parallelogram linkage is biased by a spring 126 fastened to the arm 115 
and the housing cover 100 such that the two scanning rails 102 and 103 are 
in their closest possible position with respect to each other. 
Furthermore, the contact pressure arm 124 is biased by a spring 127 such 
that its free end disposed in the recess 101 is pressed in a direction 
towards the respective sound head. 
The mode of operation of the scanning means shown in FIG. 4 is as follows. 
The respective cassette is pushed into the recess 101 in the area of the 
faces 104, 105 from the bottom side in FIG. 4A or from the backside in 
FIG. 4B such that its broad bottom will come to lie on the plate portions 
106 and 107 and its side surfaces against the inclined faces 104 and 105. 
Then the cassette is pushed forwardly, i.e. to the left in FIG. 4B. Hereby 
the scanning rails 102 and 103 are pushed apart in correspondence with the 
width of the cassette, the movements being antiparallel with respect to 
each other because of the parallelogram linkage 113, 114, 115. The 
scanning rails 102 and 103 are guided at the guide rail 110. As soon as 
the cassette has been pushed so far that it will no longer contact the 
inclined faces 104, 105 but instead the straight faces, the scanning rails 
102 and 103 will be positioned at a spacing which corresponds to the width 
of the cassette. The bottom of the cassette then will press against the 
leg 117 of the switch contact arm 116 whereby the latter is pivoted and 
its contactor 118 will touch one of the switching contacts 119 to 122. In 
this manner the cassette is identified and one of the electric motors 26 
or 53 will be controlled in response to the respective switching contact 
119, 120, 121, or 122 which has been actuated. Hereby one of the operating 
conditions is adopted as shown in FIGS. 1, 2, or 3. The corresponding 
pivoting of one sound head carrier 10, 20, or 30 is carried out while the 
cassette is being pushed further forward. The cassette then will reach the 
part of the recess 101 which is no longer covered by the plate portions 
106 and 107, thus entering the range of the winding shafts and sound head 
carriers. The cassette then may be inserted in correspondence with the 
respective type of cassette, a contact pressure leg 128 of the contact 
pressure arm 124 pushing the cassette in forward direction toward the 
sound head, thereby fixing its position. 
The switching contact 122 which identifies the narrowest cassette, i.e. the 
mini-M-cassette consequently provides for switch-on of the motor 53. The 
switch contact 121 which identifies the micro-cassette switches on the 
motor 26. The switch contact 120 identifies the mini-cassette with which 
again the sound head carrier 30 is required so that this contact too 
activates the electric motor 53. The switch contacts. 120 and 122 thus may 
be bridged or connected to each other. 
The switch contact 119 finally identifies the so-called Grundig cassette 
with which the sound head carrier 10 is required so that none of the 
electric motors 26 or 53 must be actuated, provided the basic position 
prevails as shown in FIG. 1. 
As long as no cassette has been inserted, the contactor 118 does not touch 
any of the switch contacts 119 to 122 so that a logic circuit may be used 
for control of both electric motors 26 and 53 such that they are moved 
into their inoperative position at which the sound head carriers 20 and 30 
are pivoted out of position while the sound head carrier 10 is pivoted 
into a position of operation. An electrical switch may be provided in the 
area in front of the sound heads to be operated by the cassette and 
generate a signal indicating the presence of a cassette. In this manner it 
can be safeguarded that the electric motors are not actuated erroneously 
when a cassette has been introduced (into the frontmost position). 
Control of the motors by the switch contacts 119 to 122 may be carried out 
such that the previous operating position always is maintained when a 
cassette is taken out. This has the advantage that the whole set of 
switching functions need not be carried out for each replacement of a 
cassette but only upon change of the type of cassette. 
On the other hand, however, the control also may be such that after each 
withdrawal of a cassette the sound head carrier 20 or 30 which may have 
been pivoted into operating condition is swung out again and the tape 
recorder once more adopts the basic position shown in FIG. 1 at which the 
sound head carrier 10 is effective. 
If the recorder is to be used primarily for a certain type of cassette, it 
is also possible to provide for one of the other positions to be the basic 
position which then will be adopted each time a cassette has been removed. 
This also may be programmed freely by the user. 
Finally, it should be noted that the sound head carriers 10, 20, and 30 
need not necessarily be associated with the types of cassette described in 
connection with the instant embodiment. All that has to be changed is the 
arrangement of the recording and/or erasing heads and any restraining pins 
as well as the shape of the control cam 17. Then it is also possible to 
provide as the basic condition according to FIG. 1 an arrangement for 
micro, mini, or mini-M-cassettes. 
By the way, with the basic position as shown in FIG. 1 the upper front 
sides of the pivot axes 21 and 31 serve as cassette restraining pins 
because their mutual spacing is so selected that it exactly corresponds to 
the spacing between restraining openings in the bottom side of the Grundig 
cassette. 
Instead of a drive by means of electric motors 26 or 53 it is also possible 
to provide a manually operated drive. For this purpose, for example, a 
lever might be provided to be operated by a user. It is also possible to 
provide corresponding lever connections at one of the links of the 
parallelogram linkage or at the scanning rails 102 or 103 to carry out the 
respective required pivoting of the sound head carriers when the two 
scanning rails 102 and 103 are being pushed apart. 
The various necessary pivoting or tilting motions also may be effected by 
means of racks or other mechanical couplings. FIGS. 9 to 11 show another 
variant of the scanning device. 
The basic principle of this variant resides in the provision of a hinged 
cassette compartment into the front end of which the respective cassette 
is inserted. The movement occurring upon closing causes corresponding 
scanning members which scan the width of the cassette to become displaced. 
An electrical signal then is derived from the limit position thus reached. 
Furthermore, upon closing the position of the cassette is centered within 
the compartment and the cassette is aligned in the longitudinal direction 
of the compartment. Just before the compartment is completely closed, the 
sound head carriers are adjusted, as described above, and the winding 
drives as well. Clearly, this variant affords simpler operation by the 
user because the cassette onc it has been scanned need not be lifted again 
slightly in order to place it on the winding drive shafts. 
First of all, reference is made to FIGS. 9 and 10. A recess 101 again is 
provided in the housing cover 100 (cf. also FIG. 4). The entire scanning 
means including the cassette compartment is arranged in this recess. This 
scanning means comprises two lateral pivot arms 130 and 131 which are 
pivotably mounted on a common axis 132 extending parallel to the plane of 
the cover 100. The axis 132 is supported in bearings 133 and 134 which are 
secured for rotation to the cover 100. Between them the two pivot arms 130 
and 131 hold a carrier plate 135 at which all the individual components of 
the scanning means are fastened. The carrier plate 135 includes two 
parallel recesses 136 and 137 extending transversely of the longitudinal 
extension of the pivot arms 130 and 131 and being offset with respect to 
each other. These recesses 136 and 137 serve as guide means for two 
scanning carriers 138 and 140 which thus may be displaced toward and away 
from each other. The two scanning carriers 138 and 140 each include a 
scanning leg 139 and 141, respectively,projecting vertically into the 
interior of the tape recorder and corresponding in effect to the scanning 
rails 102 and 103 of FIG. 4. Both scanning carriers 138 and 140 are of 
Lshape design in the plane of the carrier plate 135 and thus each have a 
leg extending parallel to the pivot arms 130 and 131 and another leg 142 
and 143, respectively,oriented in the direction of the other scanning 
carrier. The legs 142 and 143 each carry two spaced guide pins 144, 145 
and 146, 147, respectively, guided in the recesses 136 and 137, 
respectively, of the carrier plate 135. 
In this case too a linkage is provided to carry out corresponding parallel 
displacement in order that the scanning legs 139 and 141 may be moved when 
the cassette compartment is swung open and closed. Specifically, a pivot 
lever 148 is rotatably mounted in a pivot bearing 149 on the carrier plate 
135, the pivot bearing 149 being disposed centrally between the two 
recesses 136 and 137. The guide pins 145 and 146 are fixed to the two 
respective ends of the pivot lever 148 in an oblong hole so that upon 
rotation of the pivot lever 148 about the axis of the pivot bearing 149 
the two scanning carriers 138 and 140 are moved toward or away from each 
other. In this manner the opposed motions of the scanning carriers are 
obtained positively in combination with the provision of the recesses 136 
and 137, a condition obtained with the embodiment of FIG. 4 by virtue of 
the parallelogram linkage. 
A push-pull lever 150 is attached to one end of the pivot lever 148, in 
this case to the guide pin 146, while the other end is secured to a lever 
152 by means of a pin 151. The lever 152 is of L-shape and fixed to the 
carrier plate 135 by means of a pivot bearing 153 at the bend of the "L". 
One arm 154 of the lever 152 is engaged by a tension spring 155 in the 
middle of which a rod 156 is supported so as to be freely movable. The 
carrier plate 135 is formed with a recess 157 in the connecting range 
between the spring 155 or the rod 156 and the arm 154 of the lever 152. 
The other end of the spring 155 is fastened to a spring retainer 158 which 
in turn is held by a thrust bearing 159 mounted on the axis 132 and fixed 
against rotation with respect to the housing cover 100 by means of a 
connecting arm 160. 
As may be seen in FIG. 11, the spring retainer 158 is mounted eccentrically 
with respect to the axis 132 such that the spring 155 is tensioned when 
the cassette compartment is swung upwardly, while it is relieved when the 
compartment is pressed down. The rod 156 on the one hand engages the 
spring retainer 158 and, on the other hand, the arm 154 so that the lever 
152 is rotated in counterclockwise sense (FIG. 9). 
The other end of the lever 152 carries a wiping contact 161 which is 
insulated with respect to the lever 152 and to which an electrical lead is 
connected which is not shown. 
Upon pivoting of the lever 152 the wiping contact 161 slides along a 
contact carrier 162 which is electrically insulated with respect to the 
carrier plate 135 and in the present case carries four spaced contacts 
163, 164, 165, and 166 corresponding to the switch contacts 119 to 122 of 
FIG. 5. The contacts 163 to 166 also are connected to electrical leads 
(not shown) carrying corresponding scanning signals. 
In the open position (FIG. 11) of the scanning means the spring 155 is 
relaxed and the rod 156 has pressed the lever 152 into the position shown 
in FIG. 9 so that both scanning legs 139 and 141 are at the greatest 
possible distance from each other. Now if the cassette compartment is 
pressed down, the spring 155 is tensioned, the lever 152 is rotated in 
clockwise sense, thereby pivoting the pivot lever 148 in counterclockwise 
sense (FIG. 9) by way of the push-pull lever 150, whereby the two scanning 
carriers 138 and 140 are moved towards each other. As soon as the scanning 
legs 139 and 141 touch the side walls of the cassette having been 
inserted, further motion is prohibited so that upon further closing of the 
cassette compartment only the spring 155 is tensioned. Thereupon the 
wiping contact 161 touches one of the contacts 163 to 166 depending on the 
width of the cassette and consequently on the type of cassette, whereby an 
electrical signal is generated to identify the respective type of 
cassette. Upon opening of the cassette compartment first of all the spring 
155 is relieved, depending on the previous position, until the rod 156 
presses against the arm 154 whereby the latter is rotated in 
counterclockwise sense (FIG. 9). Hereby finally the two scanning carriers 
138 and 140 are moved away from each other. 
As the various cassettes differ not only in width but also in length, care 
must be taken that the side to be sensed by the sound head always lies in 
the same plane. To this end another plate 167 is supported for 
displacement on the carrier plate 135 by means of pins 170 and 171 secured 
to the carrier plate 135. Recesses 168 and 169 formed in the plate 167 
slide along the same. The recesses 168 and 169 are positioned parallel to 
the longitudinal extension of the pivot arms 130 and 131 so that the plate 
167 is displaceable in this longitudinal direction and, therefore, 
transversely of or at right angles with respect to the direction of 
movement of the two scanning carriers 138 and 140. 
The plate 167 projects beyond the carrier plate 135 in the direction of the 
axis 132. In this area the plate 167 is provided with a vertically 
projecting leg 172 located in the plane of the plate 167. A leg 173 
projects vertically from the leg 172 and from the plate 167 in the 
direction toward the interior of the tape recorder. An engaging plate 174 
is fixed on this leg 173 and it also has a leg 175 projecting vertically 
downwardly, i.e. toward the interior of the tape recorder. This leg 175 
comes to touch the backside of the cassette and pushes the same toward the 
front, if desired, i.e. to the right in FIGS. 9 and 10. 
When the cassette compartment is pivoted or the scanning carriers 138 and 
140 are displaced, this causes positive displacement of the plate 167 and 
consequently also of the engaging plate 174. For this purpose a lever 176 
is provided, in this case being arranged between the carrier plate 135 and 
the plate 167. One end of this lever is journalled in a pivot bearing 177 
fixed to the carrier plate 135. Approximately in the middle of the lever 
176 an oblong hole 178 is formed in which the guide pin 147 slides which 
is fixed to the scanning carrier 140 as well. The other end of the lever 
176 carries a pin 179 sliding in a control cam 180 of the plate 167. The 
control cam 180 has a substantially S-shaped course and is so designed 
that as a result the leg 175 of the engaging plate 174 will adopt the 
correct position in correspondence with the type of cassette scanned so as 
to center the cassette with respect to the scanning heads and the winding 
shafts. 
If the two scanning carriers 138 and 140 are moved towards each other, the 
scanning carrier 140 takes along the lever 176 by means of the guide pin 
147, the lever thus being swung about the pivot bearing 177. Hereby the 
plate 167 and consequently the engaging plate 174 are displaced by 
cooperation of the pin 179 and the control cam 180. Thus the displacements 
of the scanning carriers 138, 140 and the plate 167 are positively 
coupled. 
FIG. 10 further shows that the side of the carrier plate 135 from which the 
scanning legs 139 and 141 as well as the leg 175 project (bottom side) is 
covered by a cover plate 181. Thus the cover plate 181, the scanning legs 
139, 141, the scanning carriers 138 and 140 as well as the carrier plate 
135 define a cavity which presents the cassette compartment and is open at 
one side only. 
The cover plate 181 is formed with two openings 182, 183 through which the 
winding heads project. Another opening 184 may be provided through which a 
sound shaft drive may extend. 
A U-shaped guide plate 185 partly covering the scanning carriers 138 and 
140 without obstructing their displacements is provided in order to 
prevent the backside of the cassette from hitting against the scanning 
carriers 138 and 140 upon being introduced, whereby the cassette might be 
jammed. As the individual types of cassettes also are of different height, 
a resilient tongue (not shown) is provided in the area of the guide plate 
185 to press the cassettes against the cover plate 181 whereby also their 
position in height is fixed clearly. 
Finally, it must also be assured that no electrical signal causing the 
pivoting of the sound head carriers in one of the positions according to 
FIGS. 1 to 3 is generated while the scanning carriers 138, 140 are being 
displaced, in other words at a time at which the scanning has not yet been 
completed and the cassette consequently has not yet been clearly 
identified. On the other hand, it must be assured that the winding shafts 
and the scanning heads have adopted the correct position prior to the 
complete closing of the cassette compartment. For this purpose an 
electrical contact 186 is provided at the thrust bearing 159 which is 
fixed against rotation, and this contact cooperates with another movable 
contact 187 mounted on the pivot arm 131. The relative position of the 
contacts 186 and 187 is so selected that contact is established at a 
predetermined angle before the complete closing of the cassette 
compartment. This then electrically releases the scanning of the contacts 
163 to 166. If the contacts 186 and 187 on the one hand and the wiping 
contact 161 as well as the respective scanned one of the contacts 163 to 
166 are regarded as being an electrical switch, it is convenient to 
connect the same in series so as to establish a logical AND conjunction. A 
signal identifying the cassette being scanned thus cannot be generated 
until the "switch" 186, 187 is closed. 
The top side (FIG. 9) of the scanning device also is covered by a plate 
(not shown) which lies approximately in the plane of the top side of the 
housing cover plate 100 when the cassette compartment is closed. 
The cassette compartment is held in closed position by a locking means (not 
shown), as is usual with cassette recorders having a cassette compartment. 
Another locking means (not shown) may be provided in order to prevent the 
complete closing of the cassette compartment before the sound head 
carriers have been moved into the respective terminal positions. This 
locking means prevents the total closing of the cassette compartment and 
is not opened (e.g. electromagnetically) until the respective sound head 
carrier has reached its final operating position.