Pressure device for a pinch roller of a video cassette recorder

A pressure device for a pinch roller of a VCR, which includes a pinch lever connected to a function plate which is mounted on the lower portion of a main chassis to be enabled to make reciprocating movement, a pinch arm connected to pinch lever, whereby when the function plate moves the pinch lever to rotate and this rotation is directly transmitted to the pinch arm so that a pinch roller is pressed against a capstan shaft by a predetermined pressure. Therefore, the pressure device of the present invention is simple in structure, effectively improves the operation thereof and remarkably reduces size of the VCR having the pressure device.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a pressure device for a pinch roller of a 
video cassette recorder (hereinafter "VCR") and more particularly, to a 
pressure device for a pinch roller which is simple in structure so that 
the pressure device can efficiently improve its operation and productivity 
with low cost, and contribute to the simplification of VCR. 
2. Description of the Prior Art 
Various types of pressure devices for a pin roller of a VCR are well known 
in the art. One of such prior art pressure devices as shown in FIGS. 1 to 
4 has a complicated structure. The conventional pressure device includes a 
function arm 2 disposed under a main chassis 1 for rotating by itself 
about a first shaft pin 3, on one end of the function arm 2, a function 
plate 4 is disposed for reciprocally moving through a guide pin in the 
direction indicated by arrow A as shown in FIG. 1. Since a locking pin 6 
of the function plate 4 is inserted into a locking hole 2a of the function 
arm 2, the function arm 2 rotates in accordance with the movement of the 
function plate 4. 
On the other end of the function arm 2, a first connecting pin 2b protrudes 
upward through a guide hole 1a of the main chassis 1. The first connecting 
pin 2b is provided with a first link 8 rotatably connected to the first 
connecting pin 2b at one end of the first link 8 to be always pressed to 
the left side of the drawing by elastic force of a first tension coil 
spring 7. Second and third links 9 and 10 are rotatively connected to the 
other of the connecting pin 2b through a second connecting pin 11. 
A pinch lever 14 is connected to the second link 9 by a third connecting 
pin 15 and which is rotatably mounted on the main chassis 1 by means of a 
second shaft pin 12 of a pinch guide hole 14a and is resiliently supported 
by elastic force of a second tension coil spring 13 so that the second 
link 9 rotates in the clockwise direction. A pinch arm 19 having a pinch 
roller 18 which is pressed against a capstan shaft 17 is connected to the 
other of the third link 10 by a fourth connecting pin 20 and is rotatably 
mounted on a third shaft pin 16 of the main chassis 1. 
Accordingly, as shown in FIG. 1, when play mode signals (not shown) of the 
conventional pressure device for the pinch roller of the VCR are applied 
in a stop mode while the pinch roller 18 is some distance away from the 
capstan shaft 17, the function plate 4 driven by a drive source (not 
shown) moves in the direction indicated by arrow A. Since the locking pin 
6 of the function plate 4 is inserted in the locking hole 2a of the 
function arm 2, the function arm 2 rotates in a clockwise direction about 
the first shaft pin 3. And the first link 8 connected to the first 
connecting pin 2b of the function arm 2 overcomes elastic force of the 
first tension coil spring 7 and moves from the state shown in FIG. 1 to 
the state shown in FIG. 2. At the same time, the pinch lever 14 connected 
to the second link 9 overcomes the elastic force of the second tension 
coil spring 13 and rotates about the second shaft pin 12 in the 
counterclockwise direction. The pinch arm 19 connected to the third link 
10 revolves in the counterclockwise direction about the third pin 16, 
thereby forcing the pinch roller 18 of the pinch arm 19 to contact the 
capstan shaft 17. At this point, the elastic force of the second tension 
coil spring 13 which supports the pinch lever 14, delivers the pressure 
force and forces the pinch roller 18 to press against the capstan shaft 17 
as well. Additionally, the elastic force of the first tension coil spring 
7, which supports the first link 8, works as the restoring force when the 
pinch arm 19 returns from the play mode to the stop mode. 
However, the conventional pressure device for a pinch roller of a VCR has 
many components involved in the series of procedures by which the 
reciprocation movement of the function plate 4 is converted to a pressure 
movement which forces the pinch roller 18 to press against the capstan 
shaft 17. As a result, this large number of parts, and attendant 
cumulative size tolerances for the individual parts, reduce reliability of 
operation. In addition, large numbers of component parts increase 
production cost, decrease productivity, and hinder minimization of the 
sizes of products. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide a pressure 
device for a pinch roller of a video cassette recorder, which eliminates 
the above problems encountered in a conventional pressure device for a 
pinch roller of a video cassette recorder. 
Another object of the present invention relates to a pressure device for a 
pinch roller, which includes a function plate operatively connected to the 
lower portion of a main chassis, a pinch lever rotatively connected to the 
function plate, and a pinch arm operatively connected to a pinch roller, 
whereby force of the movement of the function plate is directly 
transmitted to the pinch arm through the pinch lever so that it is simple 
in structure and of low cost, and produces a small size VCR. 
Other objects and further scope of applicability of the present invention 
will become apparent from the detailed description given hereinafter. It 
should be understood, however, that the detailed description and specific 
examples, while indicating preferred embodiments of the invention, are 
given by way of illustration only, since various changes and modifications 
within the spirit and scope of the invention will become apparent to those 
skilled in the art from this detailed description. 
Briefly described, the present invention relates to a pressure device for a 
pinch roller of a VCR, which includes a pinch lever connected to a 
function plate which is mounted on the lower portion of a main chassis to 
be enabled to make reciprocating movement, a pinch arm connected to pinch 
lever, whereby when the function plate moves the pinch lever to rotate and 
this rotation is directly transmitted to the pinch arm so that a pinch 
roller is pressed against a capstan shaft by a predetermined pressure. 
Therefore, the simple structure of the pressure device of the present 
invention can effectively improve its operation and remarkably reduce the 
size of the VCR having the pressure device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now in detail to the drawings for the purpose of illustrating 
preferred embodiments of the present invention, the pressure device of a 
pinch roller of VCR as shown in FIGS. 5, 6, and 7, comprises a function 
plate 22 installed on the lower part of a main chassis 21 enabling it to 
make reciprocating movements guided by a guiding pin 21', a pinch lever 24 
which rotates centered on a shaft pin 23 relative to the movement of the 
function plate 22, and a pinch arm 28 which rotates centered on a second 
shaft pin 25 by directly receiving its rotation force from the pinch lever 
24, thereby forcing a pinch roller 27 to press against a capstan shaft 26. 
A first locking pin 29 of the function plate 22 is inserted into a locking 
hole 24a of the pinch lever 24 for making the pinch lever 24 turn to some 
degree through the movement of the function plate 22. In addition, one end 
of a first tension coil spring 30 is fixed to the pinch lever 24 and is 
supported in the counterclockwise direction, centered on the first shaft 
pin 23 while the other end of the pinch lever 24 has a locking groove 24b. 
A second locking pin 31 is fixed to one end of a pinch arm 28 and is 
inserted into the locking groove 24b of the pinch lever 24. Also, one end 
of a second tension coil spring 32 is also fixed to the pinch arm 28 so 
that the pinch arm 28 is supported by the elastic force in the 
counterclockwise direction, centered on the second pin 25. 
The pressure device of a pinch roller according to the present invention 
operates as follows: 
As shown in FIG. 5 in the stop mode position, the pinch roller 27 is 
separated from the capstan shaft 26 by some distance. When play mode 
signals (not shown) are applied, the drive power from the drive source 
(not shown) forces the function plate to move in the direction indicated 
by arrow A. 
At this time, the pinch lever 24 overcomes the elastic force of the first 
tension coil spring 30 and rotates in the clockwise direction centered on 
the first shaft pin 23 since the locking pin 29 of the function plate 22 
is inserted into the locking hole 24a of the pinch lever 24. Accordingly, 
the pinch arm 28 with the locking pin 31 inserted in the locking hole 24b 
of the pinch lever 24 rotates in the counterclockwise direction, centered 
on the second shaft pin 25 thereby forcing the pinch roller 27 to contact 
the capstan shaft 26. At this time, since the rotation of the pinch arm 28 
continues, the second tension coil spring 32 is returned from the extended 
state. This restoring force functions as pressure force on the pinch 
roller 27. Also, the first tension coil spring 30 is extended by the 
rotation of the pinch lever 24, thereby creating a tension force. This 
tension force functions as restoring force on the pinch lever 24 which 
rotates about the first shaft pin 23 in the counterclockwise, when the 
play mode is switched to the stop mode. 
Accordingly, the present invention simplifies the structure required by 
directly transmitting the movement force of the function plate 22 to the 
pinch arm 28 through the pinch lever 2 improves product reliability, 
decreases production cost, increases productivity, and reduces product 
size and weight. 
The invention being thus described, it will be obvious that the same may be 
varied in many ways. Such variations are not to be regarded as a departure 
from the spirit and scope of the invention, and all such modifications as 
would be obvious to one skilled in the art are intended to be included in 
the scope of the following claims.