Cassette holder moving mechanisms

In a magnetic recording and reproduction apparatus in which a cassette holder 11 is supported movably relative to a slide chassis 15 by two moving mechanism 16 and 17, the number of teeth of a pinion 40 at the moving mechanism 16 side is increased compared to a pinion 41 at the moving mechanism 17 side to prevent the cassette holder from coming up at the moving mechanism 16 side at the descending end of the cassette holder 11 to obtain a stable holding force. Further, racks 38 and 39 engaging with the pinions 40 and 41 at the descending end position of the cassette holder 11 is increased in tooth thickness to reduce backlash between the racks 38 and 39 and the pinions 40 and 41 at the descending end of the cassette holder 11, thereby obtaining improved operability.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to cassette holder moving mechanisms for vertically 
moving a cassette holder holding a cassette case that is held 
substantially in a horizontal position in a magnetic recording and 
reproduction apparatus in which the cassette holder is movably supported 
on a slide chassis. 
2. Description of the Background Art 
Among magnetic recording and reproduction apparatus, a so-called 8-mm video 
apparatus uses a magnetic tape. In such an 8-mm video apparatus, the slide 
chassis can hold a cassette case in which a wound magnetic tape is 
disposed. The slide chassis can be moved by a built-in vertical moving 
mechanism to an eject position where the cassette holder is ejected out 
from the video main unit, and to a play position by a slide mechanism. At 
the play position, the magnetic tape can be pulled out from the cassette 
case to run for recording or reproduction. 
The cassette holder is vertically moved relative to the slide chassis by 
moving mechanisms provided on two opposing sides so that the surfaces of 
the cassette case are moved in parallel. 
The cassette holder provides vertical and substantially parallel movement 
due to the moving mechanism provided on the opposing sides. Therefore, if 
the force on one of the moving mechanisms is biased, the cassette holder 
does not provide movement in parallel, and the setting of the cassette 
tends to be unstable. Furthermore, since a lock mechanism for fixing the 
descending end position of the cassette holder is provided at only one 
side of the moving mechanisms, the other side of the cassette holder tends 
to be moved up by a counter-force. Furthermore, when both moving 
mechanisms are synchronized by a rack and pinion mechanism, movement of 
the pinion is small relative to vertical movement of the arm in a 
condition where the arm is nearly horizontal, that is, close to a cassette 
holder locking condition. As a result, there is a problem in that a 
backlash between the rack and pinion tends to produce a dead zone to the 
vertical movement. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, there is provided a magnetic 
recording and reproduction apparatus comprising a cassette holder for 
holding a box-type cassette case having a wound magnetic tape, a slide 
chassis slidably provided in the main unit of the magnetic recording and 
reproduction apparatus for holding the cassette holder in a condition 
where the surfaces of the cassette case are vertically moved in parallel, 
and moving mechanisms individually provided over the cassette holder and 
the slide chassis at both sides of the vertical moving direction of the 
cassette holder. Each moving mechanism has two arms which are rotatable 
with respect to each other at an intermediate portion, one end of each arm 
is supported on the cassette holder and the other end is supported on the 
slide chassis. A rack and a pinion engaging with the rack are provided at 
one end of each arm, a connecting rod is rotatably supported on the 
cassette holder, and pinions are disposed individually at both ends of the 
connecting rod. 
Furthermore, the two moving mechanisms are connected by a universal 
mechanism. A first of the two moving mechanisms has a lock mechanism for 
locking the moving mechanism at a descending end position of the cassette 
holder. The second of the two moving mechanisms has an acceleration 
mechanism for accelerating the vertical movement of the second moving 
mechanism relative to the first moving mechanism. 
There is further provided according to the present invention a magnetic 
recording and reproduction apparatus comprising a cassette holder for 
holding a box-type cassette case having a wound magnetic tape, a slide 
chassis slidably provided in the main unit of the magnetic recording and 
reproduction apparatus for holding the cassette holder in a condition 
where the surfaces of the cassette case are vertically moved in parallel, 
and two moving mechanisms individually provided between the cassette 
holder and the slide chassis at both sides of the cassette holder, 
characterized in that each moving mechanism has two arms which are 
rotatable with respect to each other at an intermediate portion, one end 
of each arm is supported on the cassette holder and the other end 
supported on the slide chassis, a rack and a pinion engaging with the rack 
are provided at one end of each arm, a connecting rod is rotatably 
supported on the cassette holder, pinions are disposed individually at 
both ends of the connecting rod, and the thickness of the rack engaging 
with the pinion at a descending end position of the cassette holder is 
greater than the thickness of the rack engaging with the pinion at an 
ascending end position of the cassette holder. 
The cassette holder is vertically moved by rotation of the two arms of the 
moving mechanisms. When the arms rotate, the connecting rod is rotated 
through the rack and pinion, the arms at both sides of the cassette holder 
move in synchronization with each other, and both moving mechanisms 
operate almost at the same speed. The cassette holder is locked at the 
descending end position by the lock mechanism, and the side having no lock 
mechanism is prevented by the accelerating mechanism from moving up. 
Furthermore, since the tooth width of the rack engaging with the pinion at 
the descending end position of the cassette holder is increased, backlash 
between the rack and pinion at the descending end position can be 
decreased to reduce the appearance of a dead zone at the descending end 
position of the cassette holder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The magnetic recording and reproduction apparatus having the cassette 
holder moving mechanisms according to the present invention will now be 
described. 
In the present embodiment, an 8-mm video apparatus equipped with a reel 
brake drive mechanism as a magnetic recording and reproduction apparatus 
will be described. In this 8-mm video apparatus, the cassette holder can 
be protruded out from the video main unit by a moving mechanism, supported 
on the slide chassis, and slid to the play position relative to a base 
chassis of the video main unit. Furthermore, in the present embodiment, 
the front portion is the side where the cassette case is inserted into the 
cassette holder, and the rear portion is the reverse side. 
In the Figures, various members related to driving the magnetic tape 
provided on the slide chassis are omitted. 
As shown in FIG. 1, a magnetic tape 1 is wound around a feed reel 3 and a 
winding reel 4 and encased in a box-type in a cassette case 2. The 
magnetic tape 1 is exposed for reading by opening a front cover 5 upward. 
As shown in FIGS. 1 to 5 and FIG. 7, a cassette holder 11 is box-formed 
with openings at the front and rear, and the cassette case can be inserted 
from the front opening (at the left side in FIG. 5, and the right side in 
FIG. 7). A slide chassis 15 is box-formed with an opening at the top, and 
the cassette holder 11 can be vertically moved relative to the slide 
chassis 15 with the surfaces of the cassette case being movable in the 
horizontal direction by moving mechanisms 16 and 17 provided at the right 
and left sides (both sides of the vertical moving direction). 
Lower portions of both sides of the cassette holder 11 are formed with 
supporting portions 13 and 14 for supporting the cassette case 2, and the 
front side (opening for insertion) of the supporting portion 14 is 
provided with a tip portion 102. A corner portion 102a directing to the 
outside of the opening is formed at the tip of the tip portion 102, and 
insertion of the cassette case 2 is guided by the tip portion 102. 
The supporting portions 13 and 14 are made of aluminum, and the tip portion 
102 including the corner portion 102a of the supporting portion 14 is 
formed of stainless steel or other structure which is higher in strength 
than aluminum. The tip portion 102 is joined by caulking with the 
supporting portion 14, and the supporting portion 14 and the tip portion 
102 form a guide member 202. 
Therefore, the tip portion 102 of the supporting portion 14 is maintained 
at a high rigidity with a small plate thickness. As a result, the 
supporting portion 14 will not deform when the cassette case 2 is 
inserted, with a small increase in weight compared to a case where a 
reinforcing plate is provided. 
A stopper 12 for regulating the position of the cassette case 2 is disposed 
at the rear portion (rear end of cassette case 2 insertion). The stopper 
12 is formed by drawing the rear end of the supporting portion 13. 
Forming the stopper 12 by drawing the supporting portion 13 considerably 
improves its strength without increasing the weight. Therefore, the 
stopper 12 will not deform even when the cassette case 2 is repeatedly 
contacted against the stopper 12, thereby consistently achieving positive 
positioning. 
Then, one moving mechanism 16 will be described with reference to FIGS. 5 
and 6. 
As shown in the Figures, a pair of arms 19 and 20 are connected rotatably 
to each other through an intermediate connecting shaft 18, and extend 
between the cassette holder's front end and rear end. A front end of the 
individual arm 19 is supported on the cassette holder 11 by a supporting 
shaft 21, and the front end of the arm 20 is supported on the slide 
chassis 15 by a supporting shaft 22. Furthermore, rear end of the 
individual arm 19 is supported on the slide chassis 15 by a slot 23 and a 
supporting shaft 25, and the rear end of the arm 20 is supported on the 
cassette holder 11 by a slot 24 and a supporting shaft 26. Top ends of the 
arms 19 and 20, above the connecting shaft 18, are connected by a spring 
27 (tension spring), and the arms 19 and 20 are urged to a rising 
direction by the force of the spring 27. 
Next, the other moving mechanism will be described with reference to FIGS. 
7 and 8. 
As shown in the Figures, a pair of arms 29 and 30 are connected rotatably 
to each other through an intermediate connecting shaft 28. The front end 
of the arm 29 is supported on the cassette holder 11 by a supporting shaft 
31, and the front end of the arm 30 is supported on the slide chassis 15 
by a supporting shaft 32. Furthermore, the rear end of the arm 29 is 
supported on the slide chassis 15 by a slot 33 and a supporting shaft 35. 
With respect to the arm 30, the rear end is supported on the cassette 
holder 11 by a slot 34 and a supporting shaft 36. Top ends of the 
connecting shafts 28 of the arms 29 and 30 are connected by a spring 37 
(tension spring), and the arms 29 and 30 are urged to a rising direction 
by the force of the spring 37. 
By the function of the arms 19 and 20 and the arms 29 and 30 of the moving 
mechanisms 16 and 17, the cassette holder 11 is vertically moved while 
maintaining its horizontal position as shown in FIGS. 5 to 8. 
The moving mechanisms of the present invention are adapted to operate at 
almost the same speeds. This will be described below. 
As shown in FIGS. 5 to 8, racks 38 and 39 are formed at top ends of the 
arms 20 and 30 of the moving mechanisms 16 and 17. Furthermore, as shown 
in FIGS. 1, 3, and 4 to 9, pinions 40 and 41 are rotatably disposed at the 
rear portion of the cassette holder 11. The pinion 40 engages with the 
rack 38 of the arm 20, and the pinion 41 engages with the rack 39 of the 
arm 30. A connecting rod 42 is rotatably supported on the cassette holder 
11, and the pinions 40 and 41 are mounted individually to both ends of the 
connecting rod 42. The pinions 40 and 41 are integrally rotated by the 
connecting rod 42. 
Therefore, during horizontal movement of the cassette holder 11 by the 
moving mechanisms 16 and 17, when the individual arms 20 and 30 rotate, 
the pinions 40 and 41 are rotated through the racks 38 and 39. Since the 
pinions 40 and 41 are connected by the connecting rod 42, they rotate in 
synchronization to operate the right and left moving mechanisms 16 and 17 
at almost the same speeds. Since the rear ends of the arms 20 and 30 of 
the moving mechanisms 16 and 17 (i.e. the sides where the racks 38 and 39 
are formed) are connected to the cassette holder 11 by the slots 24 and 34 
and the supporting shafts 26 and 36, the racks 38 and 39 rotate and slide 
to acceleratingly rotate the pinions 40 and 41. As a result, even when 
different forces are applied to the moving mechanisms 16 and 17 (i.e. when 
the cassette holder is pushed in by applying a force at only one side of 
the cassette holder 11) the moving mechanism 16 and 17 positively operate 
in synchronization to vertically move the cassette holder 11. 
On the other hand, the moving mechanism 17 is provided with a lock 
mechanism 48 as a holding mechanism which holds the cassette holder 11 in 
a descending condition where the arms 29 and 30 are in declining 
positions. 
The lock mechanism 48 will be described. 
As shown in FIGS. 7 and 8, on the slide chassis 15, a hook 50 is rotatably 
mounted on a shaft 49 at the side portion of the moving mechanism 17 side 
and urged counter-clockwise by a spring 51 disposed between the side 
portion and the slide chassis 15. Further, a regulating plate 53 is 
rotatably mounted adjacent to the hook 50 by a shaft 52 and urged 
clockwise by a spring 54, and the tip portion of the regulating plate 53 
contacts against the hook 50, thereby rotating the hook 50 against the 
urging force of the spring 51 and maintaining it at a release position 
(the position shown in FIG. 7). On the other hand, a downward tensioning 
portion is integrally formed on the arm 29, and a stop pin 55 is mounted 
on the tensioning portion. Further, a lower projection 56 is integrally 
formed on the hook 50, and a release lever 105 is formed on a base chassis 
71 which slidably supports the slide chassis 15. 
Therefore, when the cassette holder 11 shown in FIG. 7 is moved down from 
the ascending position (arms 29 and 30 at rising positions), the arms 29 
and 30 decline and the stop pin 55 moves down. Then, the stop pin 55 
contacts the regulating plate 53 to press it down against the urging force 
of the spring 54. As a result, the hook 50, which has been maintained at 
the release position by the regulating plate 53, is rotated 
counter-clockwise by the urging force of the spring 51. Therefore, as 
shown in FIG. 8, the hook 50 engages with the stop pin 55 to prevent the 
rising of the arm 29, and the cassette holder 11 is bound at the 
descending position (arms 29 and 30 at the declining positions). On the 
other hand, when the projection 56 of the hook 50 contacts the release 
lever 105 of the base chassis 71, the hook 50 is rotated counter-clockwise 
against the urging force of the spring 51 to release engagement with the 
stop pin 55. Then, the arms 29 and 30 rise due to the urging force of the 
spring 37, and the cassette holder 11 moves up. 
In FIGS. 5 to 8, the numerals 57 and 58 indicate detection switches for 
detecting declining condition of the individual arms 19 and 20, and 29 and 
30, of the moving mechanisms 16 and 17 (i.e. the descending condition of 
the cassette holder 11). 
Since the lock mechanism 48 is provided only at the moving mechanism 17 
side, there is a danger that a difference in holding force occurs between 
the right and left sides when the cassette holder 11 is moved down, and 
the moving mechanism 16 side of the cassette holder 11 tends to become 
unstable. This would be prevented by staggering the engaging phase of the 
pinions 40 and 41 and utilizing a twisting force to hold the cassette 
holder 11 horizontally during moving down. However, in this case, the 
cassette holder 11 becomes inclined when it is moved up, impairing the 
appearance. 
To prevent this, an acceleration mechanism is provided at the moving 
mechanism 16 side. The acceleration mechanism will be described below. 
The pinion 40 at the moving mechanism 16 side (the side having no holding 
mechanism) has 11 teeth, whereas the pinion 41 at the moving mechanism 17 
side has 10 teeth. By increasing the number of teeth of the pinion 40, the 
moving speed of the cassette holder 11 at the moving mechanism 16 side is 
increased. 
Therefore, the moving mechanism 16 side of the cassette holder 11 is 
prevented from coming up at the descending end position, thereby 
positively holding both sides of the cassette holder 11 at the descending 
end. 
On the other hand, as shown in FIGS. 5 to 8, the racks 38 and 39 engaging 
with the pinions 40 and 41 when the cassette holder 11 is moving up differ 
in tooth thickness from the racks 38 and 39 engaging with the pinions 40 
and 41 when the cassette holder 11 is moving down. That is, teeth 38a and 
39a of the racks 38 and 39 engaging with the pinions 40 and 41 when the 
cassette holder 11 is moving up are thicker than teeth 38b and 39b of the 
racks 38 and 39 engaging with the pinions 40 and 41 when the cassette 
holder 11 is moving down. The tooth foot for all of teeth 38a and 39a and 
teeth 38b and 39b are in line with each other, but differ in the pitch 
line position. 
Therefore, when the cassette holder 11 moves down, backlash between the 
pinions 40 and 41 and the racks 38 and 39 is decreased. Backlash between 
the pinions 40 and 41 and the racks 38 and 39 is removed by the springs 27 
and 37. 
Since the tooth thicknesses are gradually increased between the teeth 38a 
and 39a and the teeth 38b and 39b of the racks 38 and 39, smooth vertical 
movement of the cassette holder 11 is achieved. 
Furthermore, as described above, the springs 27 and 37 are provided on the 
arms 19 and 20 and the arms 29 and 30 of the right and left moving 
mechanisms 16 and 17, and vertical movement of the cassette holder 11 is 
achieved by the urging force of the springs 27 and 37. Since the urging 
force of the springs 27 and 37 is capable of moving up the cassette holder 
11, shock or vibration may occur at the ascending end of the cassette 
holder 11. Therefore, a damper mechanism 43 as a damping member is 
provided to reduce such shock and vibration and moderately stop the 
cassette holder 11. 
The damper mechanism 43 will be described. 
As shown in FIGS. 7 and 8, on the slide chassis 15, a resin-made slide 
member 45 as a connecting member having a rack 44 formed at the upper 
portion is provided at the rear of the side of the moving mechanism 17 
side (rear side of the cassette holder 11). The slide member 45 is 
supported to be movable to the front and rear (right and left in FIGS. 7 
and 8), with one end supported (connected) to the rear end of the arm 29. 
An oil damper 47 is disposed at the inside of the slide chassis, and a 
resin-made pinion 46 is mounted on a rotary portion of the oil damper 47. 
The pinion 46 engages with the rack 44 of the slide member 45, and 
movement of the slide member 45 is moderated by the oil damper 47. 
When the cassette holder 11 is moved up by the moving mechanism 17, the 
arms 29 and 30 are rotated in the rising direction by the urging force of 
the spring 37. At this moment, the rear end of the arm 29 moves to the 
front along with the slide member 45 to rotate the pinion 46 through the 
rack 44. The pinion 46 is rotated moderately by the function of the oil 
damper 47 to moderate the movement of the slide member 45, and the 
cassette holder 11 stops moderately without shock or vibration at the 
ascending end. 
Since the damper mechanism 43 is disposed on the slide chassis 15 at the 
rear of the moving mechanism 17, it is unnecessary to increase the size of 
the cassette holder 11 and increase the width of the slide chassis 15. 
Furthermore, since the arm 29 of the moving mechanism 17 and the pinion 46 
of the oil damper 47 are connected through the slide member 45, which 
allows the tooth width of the pinion 46 and the rack 44 to be increased, 
viscosity of the oil damper is increased, thereby preventing the pinion 46 
and the rack 44 from being damaged and achieving a lightweight 
construction and a cost reduction. 
Further, as shown in FIGS. 4 and 9, the cassette holder 11 of the present 
embodiment is provided with a tape protector 61. The cover 5 of the 
cassette case 2 is opened when the cassette holder 11 containing cassette 
case 2 is moving down. However, during this operation, the magnetic tape 1 
may adhere to the rear side of the cover 5 due to static electricity. In 
such a case, the magnetic tape 1 is brought to the opposite side beyond 
the rotary head drum, and is not loaded properly. The tape protector 61 is 
to prevent the magnetic tape 1 from running on the rotary head drum. 
A rotary member 63 is mounted at the rear portion of the moving mechanism 
17 side of the cassette holder 11 by a supporting shaft 62, two projection 
pieces 64 and 65 are integrally formed on the outer peripheral surface of 
the rotary member 63, and the rear end of the arm 29 of the moving 
mechanism 17 is able to contact against the one projection piece 64. An 
L-formed operation member 66 is rotatably supported adjacent to the rotary 
member 63 by a shaft 6. One end extending beneath the operation member 66 
is capable of contacting against the one projection piece 65, and a slot 
68 is formed at the other end which extends horizontally. Furthermore, at 
the rear of the cassette holder 11, one end of the tape protector 61 is 
rotatably mounted by a supporting shaft 69 at a position shifted by a 
predetermined amount from the center to the moving mechanism 17 side 
(right side in FIG. 9), a connecting pin 70 is mounted at a position 
shifted from the supporting shaft 69 to the other end side of the tape 
protector 61, and the connecting pin 70 engages with the slot 68 of the 
operation member 66. 
Therefore, when the cassette holder 11 holding the cassette case 2 is at 
the ascending position, the cover 5 of the cassette case 2 is closed as 
shown in FIGS. 9 and 10. On the other hand, the tape protector 61 is 
directed downward by a predetermined angle theta (.theta.), and the tip of 
the tape protector 61 is at the outer peripheral surface of a rotary head 
drum 112 disposed on the base chassis 71 and nearly at the center in the 
radial direction. 
When the cassette holder moves down from the above condition, as shown in 
FIGS. 9 and 11, the cover 5 of the cassette case 2 is opened by a release 
mechanism (not shown) to expose the magnetic tape 1. The arms 29 and 30 of 
the moving mechanism 17 decline, and the rear end of the arm 29 contacts 
against the projection piece 64 of the rotary member 63 to gradually 
rotate it counter-clockwise in FIG. 9. Then, the projection piece 65 of 
the rotary member 63 contacts against one end of the operation member 66 
to operate (move up) the other end, moving up the tape protector 61 along 
with downward movement of the cassette holder 11. Ascending of the tape 
protector 61 is carried out with a delay from the opening operation of the 
cover 5 of the cassette case 2, and the tape protector 61 completes 
ascending immediately before the magnetic tape 1 exposed from the cassette 
case 2 opposes the outer peripheral surface of the rotary head drum 112. 
To set the cassette case 2 in position in the 8-mm video apparatus main 
unit, as shown in FIG. 1, the cassette case 2 is inserted from the front 
into the cassette holder 11 at the ascending position. When the cassette 
holder 11 is pressed down from the eject (ascending) position shown in 
FIGS. 5 and 7, the individual arms 19 and 20 and 29 and 30 of the moving 
mechanisms 16 and 17 decline, and the cassette holder 11 containing the 
cassette case 2 is moved to the descending position. The cassette holder 
11 containing cassette case 2 can be moved down while maintaining a 
horizontal orientation. The arms 20 and 30 of the right and left moving 
mechanisms 16 and 17 are synchronized by the connecting rod 42 which 
operates the racks 38 and 39 and the pinions 40 and 41 to move the right 
and left moving mechanisms 16 and 17 in synchronization with each other, 
thereby preventing the cassette holder 11 from twisting or inclining 
during descending. 
Since the number of teeth of the pinion 40 is one more than the pinion 41, 
the moving mechanism 16 side of the cassette holder 11 will not come up at 
the descending end. Furthermore, in the racks 38 and 39, since the teeth 
38b and 39b engaging with the pinions 40 and 41 during descending of the 
cassette holder 11 are thinner, backlash between the pinions 40 and 41 and 
the racks 38 and 39 at the descending end of the cassette holder 11 is 
reduced. Therefore, the cassette holder 11 will not twist or incline 
during descending. 
As shown in FIGS. 6, 8, and 9, when the cassette holder is moved down, the 
cassette holder 11 is bound at the descending position by the lock 
mechanism 48. That is, when the arms 29 and 30 of the moving mechanism 17 
decline, the stop pin 55 moves down to engage with the hook 50. As a 
result, the arm 30 is prevented from rising, and the cassette holder 11 is 
bound at the descending position. Movement of the cassette holder 11 to 
the descending position is detected by the detection switches 57 and 58. 
When the cassette holder 11 is at the ascending position, the cover 5 of 
the cassette case 2 is closed as shown in FIGS. 9 and 10, and the tape 
protector 61 is positioned near the center in the radial direction with 
the tip portion located at the periphery of the rotary head drum 112. When 
the cassette holder 11 moves down, as shown in FIGS. 9 and 11, the cover 5 
of the cassette case 2 is opened to expose the magnetic tape 1, and the 
tape protector 61 is moved up while the cassette holder 11 moves down. At 
this moment, moving up operation of the tape protector 61 is carried out 
with a delay from the operation of the cover 5 of the cassette case 2, and 
the tape protector 61 is moved up to the horizontal position at the 
descending position of the cassette holder 11 where the magnetic tape 1 
exposed from the cassette case 2 opposes the outer peripheral surface of 
the rotary head drum 112. 
Therefore, when the cassette holder 11 (cassette case 2) moves down, and 
even when the magnetic tape 1 adheres to the backside of the cover 5 of 
the cassette case 2 due to static electricity generated in association 
with operation of the cover 5, since the tape protector 61 is located 
between the magnetic tape 1 and the rotary head drum 112, the magnetic 
tape 1 is prevented from running on the rotary head drum 112. 
When the cassette holder 11 completely moves down and is bound at the 
present position by the lock mechanism 48, the slide chassis 15 is moved 
to the play position by a drive mechanism (not shown), and the cassette 
case 2 is loaded. At the play position, the magnetic tape 1 is pulled out 
from the cassette case 2, and run for recording or reproduction. 
When recording or reproduction of the magnetic tape 1 completes and the 
tape 1 stops running, loading of the cassette 2 is released, and the slide 
chassis 15 moves to the original position (eject position). When the slide 
chassis 15 moves to the eject position, as shown in FIGS. 6 and 8, the 
projection of the hook 50 comes in contact against the release lever 105 
of the base chassis 71, and the hook 50 rotates counter-clockwise against 
the urging force of the spring 51 to release engagement with the stop pin 
55. Then, the arms 29 and 30 of the moving mechanism 17 rise due to the 
urging force of the spring 37, the arms 19 and 20 of the moving mechanism 
16 rise due to the urging force of the spring 27, and the cassette holder 
11 moves up. 
When the cassette holder 11 is moved up by the moving mechanisms 16 and 17, 
the cassette holder is moved up by the urging force of the springs 27 and 
37. At this moment, when the arm 29 rises, its rear end moves to the front 
along with the slide member 44 to rotate the pinion 46 through the rack 
44, rotation of the pinion 46 is moderated by the function of the oil 
damper 47 to reduce shocks and vibration at the ascending end of the 
cassette holder 11, and the cassette holder 11 stops moderately. After the 
cassette holder 11 moves up, the cassette case 2 is taken out from the 
cassette holder 11. 
In the above-described moving mechanisms of the cassette holder 11, the 
pinions 40 and 41 are rotated by rotation of the individual arms 20 and 30 
through the racks 38 and 39, and the pinions 40 and 41 rotate in 
synchronization with each other due to the connecting rod 42, thereby 
preventing the cassette holder 11 from twisting or inclining during 
ascending. Furthermore, since the racks 38 and 39 rotate and slide to turn 
the pinions 40 and 41, rotation of the pinions 40 and 41 is increased. 
Therefore, the moving mechanisms 16 and 17 positively synchronize with 
each other, and the cassette holder 11 is vertically moved while always 
maintaining its horizontal condition. 
Since the pinion 40 has more teeth than the pinion 41, the moving mechanism 
16 is prevented from coming up at the descending end position due to right 
and left twisting of the cassette holder 11. Further, the teeth 38b and 
39b of the racks 38 and 39 are thinner than the teeth 38a and 39a, 
backlash between the pinions 40 and 41 and the racks 38 and 39 when the 
cassette holder 11 is moved down can be reduced. 
The cassette holder moving mechanisms of the present invention, in a 
magnetic recording and reproduction apparatus where the cassette holder is 
supported to be vertically movable relative to the slide chassis by the 
two moving mechanisms, has the acceleration mechanism at the rack and 
pinion mechanism disposed at the side having no holding mechanism, thereby 
preventing the cassette holder from coming up at the descending end 
position. As a result, stable holding force is obtained on both sides of 
the cassette holder. 
Furthermore, since the racks engaging with the pinions at the descending 
end position of the cassette holder are greater in tooth thickness than 
the racks engaging with the pinions at the ascending end position of the 
cassette holder, backlash between the racks and the pinions at the 
descending end of the cassette holder can be reduced. As a result, a dead 
zone at the descending end of the cassette holder is reduced, and improved 
operability is obtained.