JPH08329563A - Pinch roller supporting mechanism in magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To quickly and easily fit a main arm part and an auxiliary arm part of a supporting arm for supporting a pinch roller. CONSTITUTION: A tip part of the main arm part 17 is pivotally fitted with a pinch roller 13, while a tip part of the auxiliary arm part 18 is engaged with a rotary cam 15, and a spring 23 for energizing the pinch roller 13 toward a capstan 9 is streched between both arm parts 17 and 18, and then a regulating member 22 for regulating a counter angle α between the main arm part 17 and-the auxiliary arm part 18 not to spread out more than a prescribed angle against the spring 23 is provided on the main arm part 17. Then, the main arm part 17 and the auxiliary arm part 18 are connected with their respective base end parts to each other to be turnable independently of each other by a boss 27, and this boss 17 is rotatably fitted onto a pivot 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinch roller supporting mechanism in a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art A schematic structure of a magnetic recording / reproducing apparatus will be described with reference to FIG. 5, where 1 is a tape cassette having a supply reel 1a and a take-up reel 1b, and 2 is a magnetic tape T drawn from the tape cassette 1. Movable tape guide post for winding around the head cylinder 3, 4 full-width erasing head, 5 voice erasing head, 6 voice / control head, 7 fixed tape guide post, 8 back tension post, 9 capstan, A pinch roller support mechanism 10 has a support arm 12 rotatably supported by a pivot shaft 11. A pinch roller 13 is pivotally attached to one end of the support arm 12 and the other end thereof. The provided cam pin 14 is fitted in the cam groove 15 a of the rotary cam 15.

In the above structure, when the magnetic tape T for recording, reproduction, etc. is run, the magnetic tape T is pulled out from the tape cassette 1 by the movable tape guide post 2 and wound around the head cylinder 3 as shown in the figure, and the rotary cam 15 is rotated by a predetermined angle to support arm 1
By rotating 2 the pinch roller 13 is pressed against the capstan 9 via the magnetic tape T, and the capstan 9 is rotationally driven so that the magnetic tape T runs, and recording and reproduction are performed. Has become.

Conventionally, as shown in FIGS. 6 and 7, the support arm 12 has a main arm portion 17 formed into a substantially U shape by sheet metal bending and an auxiliary arm incorporated in the main arm portion 17. And a main arm 17
Is an arm body 17a, a rising piece 17b bent at a right angle from a base end portion of the arm body 17a, and the rising piece 1
7a has a parallel piece 17c that is bent at a right angle and is parallel to the arm body 17a, and through holes 19a and 19b that are concentrically provided in the base end portion of the arm body 17a and the parallel piece 17c.
Is rotatably fitted to the pivot shaft 11, and a pinch roller 13 is rotatably attached to the tip of the arm body 17a.

The auxiliary arm portion 18 has an arm body 18a extending in a direction substantially perpendicular to the main arm portion 17.
An engaging piece 18b extending from the base end of the arm body 18a along the main arm portion 17, a rising piece 18c bent at a right angle from the base end of the arm body 18a, and a right angle from the rising piece 18c. And a parallel piece 18d which is bent in parallel with the engagement piece 18b and is parallel to the engagement piece 18b.
Through holes 20a and 20b concentrically provided in
The cam pin 14 is rotatably fitted to the arm body 1 and has a cam pin 14 protruding from the tip of the arm body 18a.

Further, the arm body 17a of the main arm portion 17
A spring engaging piece 21 and a restricting member 22 are projectingly provided on both side edges of the auxiliary arm portion 18, and a spiral spring 23 for biasing the pinch roller 13 toward the capstan 9 is incorporated in the auxiliary arm portion 18. The spring 23 is fitted onto the support shaft 11, one end of the spring 23 is engaged with an engaging hole 24 formed in the rising portion 18b of the auxiliary arm 18, and the other end of the spring 23 is engaged with the spring. Since the engaging piece 18b of the auxiliary arm portion 18 abuts against the regulating member 22 against the spring 23, the facing angle α between the main arm portion 17 and the auxiliary arm portion 18 is a predetermined angle. It is regulated that it spreads above.
Reference numeral 25 is a retaining washer that engages with the upper groove of the pivot shaft 11.

In the above structure, when the pinch roller 13 is pressed against the capstan 9 via the magnetic tape T, the main arm portion 17 rotates rearward against the spring 23, and the magnetic tape T is pressed with a predetermined pressing force. It can be clamped.

[0008]

SUMMARY OF THE INVENTION In the above conventional configuration,
In manufacturing the main arm portion 17 and the auxiliary arm portion 18, first, a metal plate is pressed to form a predetermined shape, and through holes 19a, 19b, 20a, 20b are provided, and then the metal plate is formed. Although bending is performed in a substantially U-shape, an error is likely to occur during the bending process, and the through holes 19a, 19b, 20a, 20b cannot be formed concentrically due to the error, and the through hole 19a, 19b, 20a, 20b cannot be formed concentrically. In some cases, it could not be fitted.

When the pinch roller supporting mechanism 10 is assembled, the main arm portion 17, the auxiliary arm portion 18 and the spring 23 are provided.
The three members are fitted to the pivot shaft 11 in a superposed state, and it takes skill to fit the three members to the pivot shaft 11 while maintaining the superposed condition. After fitting the three members to the pivot shaft 11, it takes time and effort to engage both ends of the spring 23 with the main arm part 17 and the auxiliary arm part 18, and the assembling work is troublesome.

When the pinch roller 13 is pressed against the capstan 9, since the outer diameter of the pivot shaft 11 is smaller than the inner diameter of the loop portion 23a of the spring 23 and there is a relatively large gap β therebetween. In addition, the main arm portion 17 and the auxiliary arm portion 18 rotate to change the load applied to the spring 23, and the loop portion 23a is likely to be displaced in the direction indicated by the arrow A. Is not obtained,
The running of the magnetic tape T was unstable.

In view of the above-mentioned conventional drawbacks, the present invention can quickly and easily attach the main arm portion and the auxiliary arm portion of the support arm that supports the pinch roller, and obtain the spring load value as designed. An object of the present invention is to provide a pinch roller support mechanism in a magnetic recording / reproducing apparatus that can be used.

[0012]

In order to achieve the above object, the invention according to claim 1 comprises a main arm portion and an auxiliary arm portion in which a support arm for supporting a pinch roller is pivotally supported by a pivot shaft. , A pinch roller is pivotally attached to the tip end portion of the main arm portion, a tip end portion of the auxiliary arm portion is engaged with a rotary cam, and a spring for biasing the pinch roller toward the capstan is provided between the arm portions. A tensioning member is provided on one or both of the two arm portions, and restricts the opposing angle between the main arm portion and the auxiliary arm portion from expanding by a predetermined angle or more against the spring. By rotating the cam by a predetermined angle, the pinch roller is pressed against the capstan via the magnetic tape via the both arm portions, and the capstan is rotationally driven to run the magnetic tape. In the magnetic recording / reproducing apparatus described above, the main arm portion and the auxiliary arm portion of the support arm are rotatably connected to each other independently of each other by a boss, and the boss is rotatably attached to the pivot shaft. It is characterized by being fitted.

According to a second aspect of the invention, in the first aspect of the invention, the spring is fitted onto the boss, and
It is characterized in that both end portions are formed of helical springs that engage with the main arm portion and the auxiliary arm portion, respectively.

According to a third aspect of the present invention, the spring is a coil spring stretched between the main arm portion and the auxiliary arm portion.

[0015]

According to the first aspect of the present invention, when assembling the pinch roller support mechanism, a spring is stretched between the main arm portion and the auxiliary arm portion of the support arm that supports the pinch roller, and then the both arm portions are supported. It is only necessary to fit a boss that rotatably connects the base ends to the pivot shaft.

In this case, since the main arm portion and the auxiliary arm portion are connected in advance by the boss, the both arm portions can be easily attached to the predetermined positions only by fitting the boss to the pivot shaft. it can.

According to the second aspect of the invention, since the spiral spring is used as the spring, it is fitted onto the boss and both ends thereof are engaged with the main arm portion and the auxiliary arm portion, respectively. By mating, the spring can be easily attached in place.

According to the third aspect of the present invention, the spring is a coil spring, and the spring expands and contracts as set by the rotation of the main arm portion and the auxiliary arm portion, and the spring is unexpectedly displaced. Therefore, the spring load value as designed can be obtained and the magnetic tape can be stably run.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show a pinch roller support mechanism 10 according to a first embodiment of the present invention, in which a support arm 1
The base ends of the second main arm portion 17 and the auxiliary arm portion 18 are rotatably connected to each other by a boss 27,
The boss 27 is rotatably fitted on the pivot shaft 11, the loop portion 23a of the spiral spring 23 is fitted on the boss 27, and one end of the boss 27 is projectingly provided on the main arm portion 17. The other end is engaged with the coupling piece 21, and the other end is engaged with a spring engagement piece 28 protruding from the auxiliary arm portion 18. 6 and 7, the same parts as those in the conventional example shown in FIGS. 6 and 7 are designated by the same reference numerals and the description thereof will be omitted.

The boss 27 has a boss body 27a having a diameter larger than that of through holes 30 and 31 penetrating through the base ends of the main arm portion 17 and the auxiliary arm portion 18, and integrally protrudes from a lower end portion of the boss body 27a. The small diameter protrusion 27b is provided and fits into the through holes 30 and 31. After the small diameter protrusion 27b is fitted into the through holes 30 and 31, the lower end of the small diameter protrusion 27b is caulked. Thus, the retaining collar 32 is formed, and the collar 32 and the boss body 27a form the main arm portion 17.
Also, the auxiliary arm portion 18 is rotatably held (see the phantom line in FIG. 2).

The procedure for assembling the pinch roller support mechanism 10 will be described. As described above, the spiral spring 2 that is wound around the boss 27 that integrally connects the main arm portion 17 and the auxiliary arm portion 18 together.
After the loop portion 23a of No. 3 is externally fitted and both ends of the spring 23 are engaged with the spring engaging pieces 21 and 28, the boss 27 is fitted to the pivot shaft 11 as shown in FIG. Then, the retaining washer 25 may be engaged with the upper end groove portion of the pivot shaft 11.

According to the above structure, the main arm portion 17, the auxiliary arm portion 18, and the spring 23 are preassembled by the boss 27, so that the pinch roller support mechanism 10 can be assembled quickly and easily. it can.

Further, the coil spring 23 having the outer diameter of the boss 27 is suspended.
Since the inner diameter of the loop portion 23a is set to be almost the same as the inner diameter of the loop portion 23a, the loop portion 23a does not unexpectedly shift when the pinch roller 13 is pressed against the capstan 9, and thus the spring as designed is designed. The load value can be obtained, and the magnetic tape T can be stably run.

FIG. 4 shows a pinch roller supporting mechanism 10 according to a second embodiment of the present invention, in which a main arm portion 1 is provided.
The coil spring 2 is provided between the restricting member 22 projecting from 7 and the spring engaging piece 34 projecting from the engaging piece 18b of the auxiliary arm portion 18.
3 is stretched. The same parts as those of the first embodiment having the same structure as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

According to the above construction, the coil spring 23 expands and contracts as set by the rotation of the main arm portion 17 and the auxiliary arm portion 18 of the support arm 12, and the spring is prevented from being displaced accidentally. The spring load value as designed can be obtained, and the magnetic tape T can be stably run.

[0026]

According to the first aspect of the present invention, since the main arm portion and the auxiliary arm portion are connected in advance by the boss, the both arm portions can be simply fitted into the pivot shaft. Can be easily attached in place.

According to the second aspect of the present invention, since the spiral spring is used, it is fitted on the boss and both ends thereof are engaged with the main arm portion and the auxiliary arm portion, respectively. Thus, the spring can be easily attached to the predetermined position.

According to the third aspect of the present invention, the coil spring is used, and the spring expands and contracts as set by the rotation of the main arm portion and the auxiliary arm portion, and the spring is unexpectedly displaced. Since it does not exist, the spring load value as designed can be obtained and the magnetic tape can be stably run.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view of a pinch roller support mechanism according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the same.

FIG. 3 is an exploded perspective view of the same.

FIG. 4 is a partially cutaway plan view of a pinch roller support mechanism according to a second embodiment of the present invention.

FIG. 5 is a schematic plan view of a magnetic recording / reproducing apparatus.

FIG. 6 is a partially cutaway plan view of a conventional pinch roller support mechanism.

FIG. 7 is a vertical sectional view of the same.

[Explanation of symbols]

 9 Capstan 10 Pinch Roller Support Mechanism 11 Pivot Shaft 12 Support Arm 13 Pinch Roller 15 Rotating Cam 17 Main Arm Part 18 Auxiliary Arm Part 22 Restricting Member 23 Spring T Magnetic Tape

Claims (3)

[Claims] 1. A support arm for supporting a pinch roller comprises a main arm portion and an auxiliary arm portion pivotally supported by a pivot shaft, and a pinch roller is pivotally attached to a tip end portion of the main arm portion. The tip of the part is engaged with the rotating cam,
A spring for urging the pinch roller toward the capstan is stretched between the both arm portions, and one or both of the both arm portions face the main arm portion and the auxiliary arm portion against the spring. A restricting member is provided to restrict the angle from expanding by a predetermined angle or more, and by rotating the rotating cam by a predetermined angle, the pinch roller is pressed against the capstan via the magnetic tape via the both arm portions,
In a magnetic recording / reproducing apparatus in which a magnetic tape is made to run by rotationally driving the capstan, the main arm portion and the auxiliary arm portion of the supporting arm can be rotated independently of each other by a boss. A pinch roller supporting mechanism in a magnetic recording / reproducing apparatus, wherein the boss is rotatably fitted onto the pivot shaft. 2. The spring is a helical spring fitted onto the boss and having both ends engaged with the main arm portion and the auxiliary arm portion, respectively.
A pinch roller supporting mechanism in the magnetic recording / reproducing apparatus as described above. 3. The pinch roller support mechanism in a magnetic recording / reproducing apparatus according to claim 1, wherein the spring comprises a coil spring stretched between a main arm portion and an auxiliary arm portion.