Idling rotation mechanism used in the housing of a video cassette tape recorder

An idling rotation mechanism in a housing of a video cassette tape recorder, including a cassette loading device for loading and unloading a cassette in and out of a deck, a tape loading device for moving a video cassette tape inserted in the deck into a position of magnetic transformation, a single motor for driving the cassette loading device and the tape loading device, said motor being able to rotate in clockwise and counterclockwise direction, a loading cam device for preventing the tape loading device from being driven during the operation of the cassette loading device, and an idling rotation device of the housing for preventing the cassette loading means from being driven during the operation of the tape loading device, after the completion of the cassette loading. Both the operation of the cassette holder and the idling rotation may be simultaneously attained according to the present invention.

BACKGROUND OF THE INVENTION 
The present invention relates to an idling rotation mechanism used in the 
housing of a video cassette tape recorder (VTR), which rotates idly by 
itself as well as operates a cassette holder through reciprocating 
rectilinear motion of a rack by a loading cam, which includes circular cam 
part and a geared part. 
Conventionally, a VTR includes a housing motor for moving the video 
cassette tape (VCT) in and out of the VTR, and a separate loading motor 
for moving the inserted VCT in and out of a drum. The housing motor and 
the loading motor are separately driven during the initial and the final 
operation of the VTR. 
Thus, the conventional VTR, having a plurality of component elements for 
both the housing motor and the loading motor, becomes quite complicated. 
As a result of the added complication of a separate housing and a loading 
motor, the rate of malfunctioning is quite high, repairs become more 
difficult, and the size and weight of the VTR must be increased to 
accomodate the added components. Consequently, it becomes difficult to 
make a compact and light VTR having both a loading motor and a housing 
motor. 
Moreover, in the front loading type VTR, the idling rotation mechanism is 
attached on the outside of the housing, which includes timer gears, worm 
gear housing and eject springs on the side arm to operate the cassette 
holder and to mount and dismount the cassette tape on the head drum. But 
as a result of the complexity of the mechanism, the assembly operations 
become more difficult and the production costs become higher. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an idling rotation 
mechanism used in the housing of a VTR so that a single driving source can 
mount and dismount a VCT from the VTR as well as load and unload the VCT 
from the playback and recording tap heads, thereby simplifying the 
structure of the idling rotation and the component elements to cut down 
the production costs and the assembling time to improve the productivity 
and the miniaturization of the products. 
To achieve the above-mentioned object, an idling rotation mechanism of the 
present invention includes: a cassette loading device for loading and 
unloading a cassette in and out of a deck; a tape loading device for 
moving a video cassette tape inserted in the deck into a position of 
magnetic transformation; a single motor for driving the cassette loading 
device and tape loading device, the motor being able to rotate in the 
clockwise directions and counter clockwise; a loading cam device for 
preventing the tape loading device from being driven during the operation 
of the cassette loading device; and an idling rotation device of the 
housing for preventing the cassette loading device from being driven 
during the operation of the tape loading device, after the completion of 
the cassette loading.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention will now be described specifically with reference to 
the accompanying drawings. 
In the embodiment of the present invention, FIG. 1 and FIG. 2 are views 
illustrating an idling rotation mechanism of a housing of the present 
invention. A loading cam 1, driven by a loading motor (not shown), is 
established on a shaft formed in a deck (not shown). A circular cam part 
(nongeared part) 1a and a geared part 1b are formed on the periphery of 
the loading cam 1, and a cam groove 1c is formed in the flat surface of 
the loading cam 1. Further, a pinion 2 is established in a side of the 
loading cam 1 and the pinion 2 is driven by the rotational force of the 
loading cam 1. The pinion 2 is formed with a double pinion and a circular 
cam part 2a, a geared part 2c and a cam part 2b are formed on the 
periphery of circular cam part 2a and the double pinion, respectively. The 
geared part 2c of the pinion 2 is engaged with the geared part 1b of the 
loading cam 1 to rotate the pinion 2. 
On the other hand, a pair of racks 3 and 3' are integrally formed, and the 
geared part 2d formed on the pinion 2 is engaged with the rack 3. Also, 
the rack 3' is engaged with an operating gear 4a of a side arm 4 which is 
fitted with a supporting shaft 8 mounted on the side face of a housing 5 
to be rotated along with the supporting shaft 8. 
A circular cam part 4b is formed on the other periphery of the operating 
gear 4a. Further, an operating groove 4c is formed in the side arm 4 to 
hang a holder pin 6a secured to a cassette holder 6 into the groove 4c. 
The holder pin 6a is slidingly moved along a guide slot 7 formed on the 
side wall of the housing. 
Therefore, the rotational force transmitted to the pinion 2 by the loading 
cam 1 is transmitted to the side arm 4 via the racks 3 and 3' to operate 
the cassette holder 6. Moreover, the loading cam 1 can rotate idly by the 
ciruclar cam part 1a of the loading cam 1 and the circular cam part 2a of 
the pinion 2. 
Referring to FIG. 3, the cam groove 1c is formed on the loading cam 1, a 
sector gear 10 is connected with the same groove 1c by a pin 9. A tape 
loading gear 11 is engaged with the sector gear 10 and another tape 
loading gear 11a is engaged with the tape loading gear 11. Two pole bases 
13 and 13a are connected with the loading gears 11 and 11a via links 14 
and 14a respectively to move along a pair of loading grooves 12 and 12a 
and to closely contact a tape onto a drum 15 when the tape is laoded. 
The operation of the present invention with the above structure will now be 
explained. 
As shown in FIG. 1, when the VCT is inserted into the cassette holder 6 in 
the housing 5, the loading motor (not shown) is activated by sensors 
located in the cassette holder 6. The loading cam 1 is rotated in a 
counterclockwise direction as shown in FIG. 1(B) by the rotational force 
of the loading motor transmitted to the loading cam 1. 
Therefore, the rotational force of the loading cam 1 is transmitted to the 
pinion 2 since the geared part 1b formed on the loading cam 1 is in mesh 
with the geared part 2c of the pinion 2. The rack 3 is moved in a left 
direction in FIG. 1(B) according to the clockwise rotation of the pinion 2 
since the other geared part 2d formed on the pinion 2 is in mesh with the 
rack 3. The driving force is transmitted to the rack 3' formed integral 
with the rack 3. 
Further, the operating gear 4a of the side arm 4 engaged with the rack 3' 
is rotated around the supporting axis 8 along with the side arm 4 in a 
clockwise direction. Accordingly, the holder pin 6a hung in the operating 
groove 4c of the side arm 4 slides down along the guide slot 7 formed on 
the side wall of the housing 5 to load the cassette tape inserted into the 
cassette holder 6 as shown in FIG. 2(A). 
At this time, a tape loading device having the sector gear 10 and the 
loading gears 11 and 11a is not driven since the device rotates along the 
track of the concentric circle of the cam groove 1c formed on the loading 
cam to have no displacement. 
On the other hand, when the geared part 1b of the loading cam 1 is 
disengaged with the geared part 2c of the pinion 2, the circular cam part 
1a of the loading cam 1 contacts with the other circular cam part 2a of 
the pinion 2, so that the rotational force of the loading cam 1 is not 
transmitted to the pinion 2. Consequently, the rotation of the pinion 2 is 
discontinued and the loading cam 1 rotates idly by itself. 
At this time, the sector gear 10 is rotated simultaneously with the idling 
rotation of the loading cam 1, while the pin 9 hung in the cam groove 1c 
of the loading cam 1 is moved along the cam groove 1c as shown in FIG. 3. 
The loading gear 11a engaged with the sector gear 10 and the other loading 
gear 11 engaged with the loading gear 11a are rotated to move the pole 
bases 13 and 13a along the loading groove 12 and 12a, respectively. 
Accordingly, the drum 15 contacts with the tape to operate the tape. 
Thereafter, the operation of the loading motor is discontinued and the 
rotational force is not transmitted to the loading cam 1. 
On the contrary, in case of unloading the VCT, the loading motor is again 
activated to rotate the loading cam 1 in the clockwise direction as shown 
in FIG. 2(B), so that the tape loading device operates in the opposite 
direction to unload the tape from the drum 15. As shown in FIG. 2(A) and 
2(B), the geared part 1b of the loading cam 1 is again engaged with the 
geared part 2c of the pinion to transmit the rotational force fo the 
loading cam 1 to the pinion 2. In succession, the rack 3 in mesh with the 
geared part 2d of the pinion is straightly moved in the right direction as 
shown in FIG. 2(B). The operating gear 4a of the side arm 4 in mesh with 
the other rack 3' which is formed integral with the rack 3 is rotated 
around the supporting shaft 8 in the counterclockwise direction by 
transforming the rectilinear motion of the rack 3' into the rotary motion 
of the operating gear 4a. 
Therefore, the holder pin 6a of the cassette holder 6 moves along the guide 
slot 7 formed on the side wall of the housing 5, and then the VCT inserted 
in the deck is unloaded to return the initial state. 
Further, in the other embodiments, said actions and effects can be 
accomplished as the gear tooth are formed on the entire periphery of the 
loading cam 1 and the circular cam part 2b of the pinion 2 contacts with 
the rack 3, or the circular cam part 4b of the operating gear 4a formed 
integral with the side arm 4 contacts with the other rack 3' to rotate 
idly. Namely, the idling rotation also occurs in the circular cam part 2b 
of the pinion 2 or the circular cam part 4b of the operating gear 4a. 
As mentioned above, the operation of the cassette holder and the idling 
rotation may be simultaneously attained according to the present 
invention. Moreover, the present invention may decrease the number of 
component elements in more simple structure to cut down the production 
costs and the assembling time, and to improve the productivity and the 
miniaturization of the products. 
The invention is in no way limited to the embodiments described 
hereinabove. Various modifications of disclosed embodiments as well as 
other embodiments of the invention will become apparent to persons skilled 
in the art upon reference to the description of the invention. It is 
therefore contemplated that the appended claims will cover any such 
modifications or embodiments as fall within the true scope of the 
invention.