JPH03127352A - Pinch driving device for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To miniaturize a device and to contrive the reduction in weight by independently providing a mechanism which turns a pinch arm based on the turning of a sector arm and a mechanism which causes the pressing force to act on a pinch roll which is already brought into contact with a capstan. CONSTITUTION:In the operation range of a light turning load up to the approach of a pinch roll 10 to the capstan, a tooth part 70 of a sector arm 68 and a pinch gear 78 of a pinch arm 75 are engaged with each other to turn the pinch arm 75. The pressing operation of a heavy turning load after the contact of the pinch roll 10 to the capstan is executed by the pin of the pinch arm 75, the cam part of the sector arm 68, and an energizing means. Since the pressing force of the pinch roll 10 is generated by the energizing means at this time, the strong force is not applied to the means which turns the sector arm 68. The tooth part 70 and the pinch gear 78 are engaged with each other only at the time of turning the pinch arm 75 but are disengaged from each other at the time of causing the pressing force to act on the pinch roll 10. Thus, the force applied to the gear part or the like is reduced to miniaturize the device.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pinch drive device in a magnetic recording/reproducing device.

Conventional technology Conventionally, in a cassette-type video tape recorder, a magnetic tape is pulled out from a tape cassette and wound around the outer periphery of a rotating drum disposed near the tape cassette to record or play back video signals. By sandwiching the magnetic tape between the rollers, a driving force for running the magnetic tape was applied.

For example, as shown in FIG. 11, a magnetic tape 203 is pulled out from a tape cassette 213 in the directions of arrows 202 and 205 by loading roller posts 201 and 204, and wound around a rotating drum 206 from both sides.
The magnetic tape 203 was sandwiched between a capstan 208 rotated by a capstan 208 and a pinch roller 209. The pinch roller 209 is mounted on a pinch arm 211 that rotates around an axis 210, so that the pinch roller 209 is mounted on the loading roller post 201 and 204 at the same time as the arrow 21.
It was being pulled out in two directions.

As a drive mechanism for rotating the pinch arm 2+1, for example, a pinch gear concentric with the shaft 210 can be rotated together with the pinch arm, and a rotating sector arm is provided that has teeth that mesh with the pinch gear of the bracket. is used. In such a device, by applying a turning force to the sector arm, the pinch arm 211 is turned and the pinch roller 209 is moved, and the pinch roller 209 is pressed against the capstan 208.

Problem to be Solved by the Invention However, in such a conventional configuration, the rotation force applied to the sector arm directly causes the pinch roller 209 to
Because it presses the capstan 208 against the capstan 208, a relatively large force is required, and the pinch gear, teeth, and other parts must be large enough to withstand such a large force. . Therefore, there is a problem in that the device becomes larger.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to solve these problems and to reduce the force applied to gear parts and the like, thereby making it possible to downsize the device.

Means for Solving the Problems In order to achieve the above object, the present invention includes a pinch arm that can pivot around a first axis, and is mounted on the pinch arm, and by pivoting the pinch arm, a a pinch roller movable from the position of the capstan to the installation position of the capstan outside the tape cassette;
a pinch gear that is rotatable together with the pinch arm around an axis; a central part is rotatably supported around a second axis; a tooth part that can engage the pinch gear is provided at one end; a sector arm that pivots the pinch arm so that the pinch roller moves toward the capstan due to engagement between the teeth and the pinch gear when the sector arm pivots about a second axis; and the other end of the sector arm; means for pivoting the sector arm around the second axis in conjunction with the sector arm, a cam provided on the sector arm, and a cam provided on the pinch arm for causing the pinch roller to approach the capstan. a pin that is accessible to the cam portion when the pinch arm pivots, and a biasing means that is linked to the second shaft, and the pin is configured to move the tooth portion and the pinch gear so that the pinch roller approaches the capstan. The pinch arm is configured to be disengaged from each other after the pinch arm rotates, and the cam portion is engaged with the pin by the pivoting operation of the sector arm after the tooth portion and the pinch arm are disengaged from each other. The capstan biasing means is configured such that a second shaft is attached to the capstan in a direction in which the pinch roller presses the capstan when the sector arm rotates after the cam portion and the pin engage with each other. It is designed to be powerful.

Effect: According to this configuration, in an operating range where the turning load is small until the pinch roller approaches the capstan, the pinch arm is turned by the engagement of the teeth of the sector arm and the pinch gear of the pinch arm. After the pinch roller contacts the capstan, the pressing operation that increases the turning load is performed by the pin of the pinch arm, the cam portion of the sector arm, and the biasing means. At this time, since the pressing force of the pinch roller is generated by the urging means, no large force is applied to the means for turning the sector arm. Further, the teeth and the pinch gear only engage when the pinch arm is rotated, and are disengaged when applying a pressing force to the pinch roller, so no large force is applied to these teeth or the pinch gear.

Embodiment In FIG. 1, 1 is a main body chassis, 2 is a tape cassette attached to the chassis 1, and a supply reel 3 and a take-up reel 4 are disposed within the cassette 2. Notches 5 formed in the front and bottom parts of the cassette 2 when the cassette 2 is attached to the chassis 1. 6. 7
The expansion post 8, the first loading roller post 9, the pinch roller 10, the second loading roller post 11, the third loading roller post 12, and the tension post 13 of the recording/reproducing device are installed inside the magnetic tape 14, respectively. inserted. 15.16.17
is the first. Second and third loading roller posts 9
．． 11.12 was installed. The second and third boats. 19.20.21 is the 1st. 15.16.17 respectively. With the second and third loading guides, the first and second loading guides 19
．． 20 has a common guide 22 in its middle portion, and the first and second loading guides 19 and 20 are interchanged so that their paths intersect at the common guide 22, and the first loading guide 19 approaches the rotating drum 23. in the direction of
The second loading guide 20 extends in a direction away from the rotating drum 23. The third loading roller post 12 wraps the magnetic tape 14 pulled out from the supply reel 3 side around the rotating drum 23 from the left side in the figure when the third bow H7 moves along the third loading guide 21. When the first boat 15 moves along the first loading guide 19 and the common guide 22, the first loading roller post 9 transfers the magnetic tape 14 pulled out from the take-up reel 4 side to the rotating drum 23 from the right side in the figure. Wrap it around. Second loading roller post 1
1, the second boat 16 moves following the first boat 15 and extends the magnetic tape 14 pulled out by the first loading roller post 9 to the side opposite to the t-th loading roller post 9. 24 is a branch pointer arm provided on the entrance side of the common guide 22; 25 is a branch pointer arm provided on the exit side of the common guide 22; Second loading guide 19.20
and the common guide z2.

30 is a capstan fixedly provided on the chassis 1 outside the mounting position of the cassette 2. 32 is an audio control head fixed to the chassis 1 between the loading end position of the second loading roller post 11 and the capstan 30. 33 and 34 are fixed posts arranged on both sides of the audio control head 32. A stopper 35.36° 37 for supporting each loading roller post (9, 11, 12) is provided at the loading end position.

Next, each mechanism for performing the loading operation will be explained. In FIG. 1, the loading motor 42 is interlocked with arc gears 57, 58 via a gear mechanism +16, and the first to third bows 15 to 17 are connected to these arc gears 57, 58 via links or the like. It is linked. Therefore, by rotating the loading motor 42 in the forward or reverse direction, these boats 15 to 17 can be moved to the respective guides 19 to 2.
It is possible to run along 2.

In FIGS. 1 to 5, reference numeral 75 denotes a pivoting pinch arm formed in a fan-shaped plate shape, and as shown in FIG. It is rotatably supported on an upright shaft 77. The pinch roller 10 is mounted on the upper surface of the tip of the pinch arm 75. A pinch gear 78 having several teeth is formed on a portion of the circumferential surface of the boss portion 76 . A sector arm 68 is for driving the pinch arm 75, and its central portion is rotatably supported by a shaft 69. One end of this sector arm 68 is formed into an arc shape, and a portion thereof is provided with several tooth portions 70 that mesh with a pinch gear 78, and the remaining portion thereof is formed with a toothless portion 71 that remains arc-shaped. There is. Missing tooth portion 7 in sector arm 68
A recessed portion 73 is provided near the shaft 69, and a cam portion 122 is formed at the inner edge of the recessed portion 73 on the side closer to the shaft 69. This cam portion +22 is formed in a tapered shape such that the distance from the shaft 69 gradually increases as the sector arm 68 rotates counterclockwise around the shaft 69 in the figure. A cam pin 72 is provided at the other end of the sector arm 68, and this cam pin 72 engages with a cam groove 48 of a cam gear 47 forming a part of the gear mechanism 116. The cam groove 48 includes a circular arc portion 48a that extends substantially along the outer circumference of the cam gear 47, and an inclined portion 48b that is continuous with the terminal end of the circular arc portion 48a and gradually approaches the center of the cam gear 47. Continuing from this inclined portion 48b, there is a bent portion 48c that is sharply bent toward the center of the cam gear 47. If? is a presser lever, which is rotatably supported by a shaft 80 mounted on the chassis 1. One end of this presser lever +17 has a spring 118
is biased counterclockwise in the figure.

A tapered edge 119 is formed on the presser lever 117, and this edge +19 engages with the fixing pin 83 of the pinch arm 75 when the presser lever 117 is biased counterclockwise by the spring 118. , pinch arm 7
5 can be prevented from turning. and tapered edge 11
9 can hold the pinch arm 75 at the predetermined position shown in the figure by pinching the fixing pin 83 between the fixing pin 83 and the stopper 115 provided on the chassis 1 by the biasing force of the spring till. The other end of the presser lever 117 has a cam surface 1.
20 is formed.

A cam piece +21 is attached to the cam gear 47, and as the cam gear 47 rotates, this cam piece 121 hits the cam surface 120, causing the presser lever 117 to rotate in the clockwise direction in the figure against the spring 118. Accordingly, the engagement between the edge 119 and the fixing pin 83 can be released.

Presser foot lever 11? A lever 7 is attached to the shaft 80 for supporting the
9 is similarly rotatably supported, and a shaft 69 for supporting the sector arm 68 is connected to this lever 7.
It is planted at one end of 9. The other end of the lever 79 is
A compression spring 8 provided between this other end and the chassis 1
1 is biased clockwise in the figure. Reference numeral 84 denotes a stopper mounted on the chassis l, which positions the shaft 69 by regulating the upper limit of clockwise rotation of the lever 79.

The starting end portion of the first loading guide, the branch pointer arm 24, and parts around it are mounted on the pinch arm 75 and rotate together with the pinch roller 10.

When loading the magnetic tape I4, the driving force of the loading motor 42 drives the first to third boats 15 to 17 through the gear mechanism +16 and the circular arc gears 57 and 58.
is guided by each of the loading guides 19 to 22 and moves toward the loading end position as shown in FIG.

Until the state shown in FIG. 6 is reached, the lever 79 is stopped at the stopper 84 by the compression spring 81, the cam pin 72 of the sector arm 68 is engaged with the arcuate portion 48a of the cam groove 48, and The fixing pin 83 is the spring 11
Since the sector arm 68 is held between the edge 119 of the presser lever 117 and the stopper 115, which is biased at 8, the sector arm 68 is held at the position shown in FIG. Now, in the state shown in FIG.
When the cam gear 47 further rotates from this state, the cam piece 121 pushes the presser lever 117 against the spring 118, thereby causing the engagement between the edge 119 and the fixing pin 83. The connection is canceled.

This state is shown in FIG.

At this point, the cam pin 72 has reached the inclined part 48b of the cam groove 48, and as shown in FIG. Turn counterclockwise. Then,
Teeth 70 pivot pinch arm 75 clockwise via pinch gear 78 and pinch roller 10 contacts capstan 30 . At this time, the tooth portion 70 and the pinch gear 78
The toothless portion 71 of the safety arm 68 comes into contact with the boss portion 76 of the pinch arm 75. Further, at this time, the rotation of the pinch arm 75 causes the fixing pin 83 to enter the recessed portion 73 of the sector arm 68 .

When the cam gear 47 further rotates, the sector arm 68
The cam pin 72 enters the bent portion 411c of the cam groove 48 and rapidly approaches the center of the cam gear 47. Then, the ninth
As shown in the figure, the sector arm 68 further pivots counterclockwise, and the cam portion 122 comes into contact with the fixing pin 83.

At this time, the toothless portion 71 is connected to the boss portion 76 of the pinch arm 75.
, and the engagement between the two is released.

When the cam gear 47 further rotates from this state,
The cam pin 72 tends to move closer and closer to the center of the cam gear 47. However, after the cam portion 122 contacts the fixing pin 83, the sector arm 6
The lever 79 moves away from the stop 84 and moves the shaft 80 against the force of the compression spring 81 so that the shaft 69 will swing and the position of the shaft 69 will change as the cam gear 47 rotates.
Turn around the counterclockwise direction in the diagram. As a result, a clockwise biasing force is generated on the shaft 69, and this biasing force causes the cam portion 122 to strongly push the fixing pin 83, causing the pinch arm 7
5 in the clockwise direction in the figure, the pinch roller 10 is pressed against the capstan 30 with a required force, and the magnetic tape 14 is pressed.
be sandwiched between the two. FIG. 10 shows that the cam pin 72 is brought closest to the center of the cam gear 47 in this way,
Indicates the state when the loading operation is completed.

In this way, since the pressure spring 81 generates the force by which the cam portion 122 presses the fixing pin 83, the cam groove 48 of the cam gear 47 and the cam pin 72 of the sector arm 68
does not bear this force, and therefore these cam grooves 48 etc. do not require great strength.
It becomes possible to reduce the size and weight of these parts. Further, the tooth portion 7Q of the sector arm 68 and the pinch gear 78 of the pinch arm 75 are only used for the rotation operation of the pinch arm 75, and are released from engagement with each other after the pinch roller 1G contacts the capstan 3Q. Therefore, no large force is applied to these tooth portions 70 and pinch gear 78, and therefore these parts do not require great strength, making it possible to reduce the size and weight of these parts.

At the time of unloading, the loading motor 42 is reversed to perform operations in the reverse order to the above. That is, first, the cam portion 122 and the fixing pin 83 are separated and the pinch roller 10. The pressing force of is released, and then the teeth 70 and the pinch gear 78 are engaged, the pinch arm 75 is rotated to its original position, and the engagement between the cam piece +21 and the presser lever 117 is released, so that the fixing Pin 83 is sandwiched between edge 119 and stopper 115, thereby positioning pinch arm 75. Next, each bow [5 to 17] moves toward the starting end side of each loading guide 19 to 21, and finally returns to the unloading state shown in FIG. 1.

Effects of the Invention As described above, the present invention includes a mechanism for rotating the pinch arm based on the rotation of the sector arm, and a mechanism for applying a pressing force to the pinch roller after contacting the capstan due to this rotation. Because these parts are made separate, large forces are not applied to the means for rotating the sector arm or the gear for rotating the pinch arm, and as a result, there is no need to increase the strength of these parts, resulting in their small size and light weight. It is possible to aim for

[Brief explanation of the drawing]

FIG. 1 is a plan view of the main parts of a magnetic recording and reproducing device based on an embodiment of the present invention, FIG. 2 is a plan view showing only the pinch drive device in FIG. 1, and FIG. 3 is a part of the portion in FIG. 2. Fig. 4 is a front view of the main parts in Fig. 2, Fig. 5 is a front view of other main parts in Fig. 2, and Figs. 6 to 1O show the pinch drive device. FIG. 11 is a schematic plan view of a conventional magnetic recording/reproducing apparatus. 2... Tape cassette, 10... Pinch roller, 3
0... Capstan, 47... Cam gear, 68...
・Sector arm, 69...axis, 70...teeth, 7
2...Cam pin, 75...Pinch arm, 77...
・Shaft, 78...Pinch gear, 79...Lever 81・
...Crimp spring, 83...Fixing pin, 122...Cam part.

Claims (1)

[Claims] 1. A pinch arm that can pivot around a first axis, and is mounted on this pinch arm, and can be moved from a position inside the tape cassette to a capstan installation position outside the tape cassette by pivoting the pinch arm. a pinch roller rotatable around the first shaft integrally with the pinch arm; a central portion supported rotatably around a second shaft, and one end portion capable of meshing with the pinch gear. a tooth portion is provided, and the second
a sector arm that pivots the pinch arm such that the pinch roller moves toward the capstan due to engagement between the teeth and the pinch gear when the sector arm pivots about the axis of the sector arm; means for pivoting the sector arm about the second axis; a cam portion provided on the sector arm; a pin that is accessible to the cam portion when the arm pivots; and a pin that is accessible to the cam portion when the arm pivots;
biasing means interlocked with a shaft of the gear, and the teeth and the pinch gear are configured to be disengaged from each other after the pinch arm is pivoted so that the pinch roller approaches the capstan, The cam portion is configured to engage the pin by a pivoting movement of the sector arm after the tooth portion and the pinch arm are disengaged;
and a magnetic recording device, wherein the biasing means is configured to bias the second shaft in a direction in which the pinch roller presses the capstan when the sector arm rotates after the cam portion and the pin engage with each other. Pinch drive device in playback equipment.