JPS6076046A - Auto-reverse device of tape recorder - Google Patents

Abstract

PURPOSE:To attain miniaturization and to prevent impairment of balance and a malfunction of a flywheel by having such a constitution where a pressure projection part has a contact with a contact part in case a detached state lasts between the contact part of a cam follower and the cam surface and then a revolution transmitter works to actuate a pinch roller switching mechanism. CONSTITUTION:When a tape is completely taken up to a right reel, a friction mechanism set between a large gear 26a and a reel shaft 1a generates a slip. Then the shaft 1a stops and a contact part 33a is detached from a cam surface 11a at a position where the part 33a has the shortest distance from a shaft 10a. Thus a pressure projection part 12a has a contact with the part 33a, and a rotary plate 7a turns against a spring 27a to separate a gear 9a from the gear 26a. Thus the transmission of revolving power to the gear 26a is cut off. While a node action plate 25 energizes and turns a development spring 22 clockwise and shifts quickly a switch plate 17 to the left side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an auto-reverse device 4 for a tape recorder that detects when a reel shaft has stopped and switches between left and right pinch rollers.

[Technical ignorance of the invention]

Traditionally, auto-reverse devices for tape recorders are
The end of the tape is detected electrically and an electromagnetic plunger is operated to switch between the left and right pinch rollers, or the tension at the end of the tape is mechanically detected and the pinch roller is operated using the rotational force of a flywheel, etc. There are known devices that operate by switching.

[Problems with background technology]

A device that electrically detects the end of a tape is equipped with an electromagnetic plunger, which results in a complicated structure and is disadvantageous in terms of miniaturization.

In addition, devices that utilize the rotational force of the flywheel generally have a pin set up on a part of the flywheel and use this pin to kick the pinch roller switching mechanism, which may impede the balance of the flywheel. At startup, the tape tension temporarily increases, so there is a risk that this will be detected and cause a malfunction.

[Purpose of the invention]

The present invention was made based on these circumstances, and
The purpose is to provide an auto-reverse device for a tape recorder that does not require accessory parts such as electromagnetic plungers, is small and easy to dispense, and is free from the risk of disturbing the balance of the flywheel or causing malfunctions.

[Summary of the invention]

The auto-reverse device for a tape recorder according to the present invention includes:
A rotation transmitting body, a cam follower, and a presser assisting part are symmetrically provided.The rotation transmitting body is equipped with an eccentric circular cam surface and a pressing protrusion, and the reel shaft is equipped with a pressing biasing part. The rotation is transmitted to the reel shaft via the rotation transmission body and further via the friction mechanism. While the reel shaft is rotating, the press +14 urges the cam follower and causes the contact part provided on a part of the cam follower to slide into contact with the cam surface, but the reel shaft stops. When the biasing force of the pressing biasing part disappears and the contact part comes to stay at a position away from the cam surface, the pressing protrusion hits the contact part and the rotation transmitting body moves to the disengaged position with respect to the reel shaft. Move to. The pinch roller switching mechanism operates in response to the operation of the rotation transmitting body. Also, when the rotation transmitting body moves to the uncoupled position,
The presser auxiliary member is moved by this rotation transmitting body or the member supporting it, and this presser auxiliary member applies a biasing force to the cam follower in place of the pressing biasing portion, causing the contact portion of the cam follower to slide into contact with the cam surface. .

That is, if the contact portion of the cam follower continues to be separated from the cam surface, the suppressing protrusion hits the contact portion, the rotation transmitting body is dislocated, and the pinch roller switching mechanism is activated.

With this configuration, the pinch roller switching mechanism does not operate as long as the reel shaft is rotating, and the same mechanism operates when the reel shaft stops, eliminating the need for accessory parts such as electromagnetic plungers, resulting in a smaller size. is easy to measure.

Furthermore, there is no risk of disturbing the rotational balance of the flywheel or causing malfunctions during startup or the like.

[Implementation sequence of the invention]

The figures show one embodiment of the present invention, and FIG. 1 shows a state in which the right reel shaft 7a is rotating, and FIG. 4 shows a state in which the left reel shaft 1b is rotating. Furthermore, FIGS. 12 and 3 show the process of changing from the state shown in FIG. 1 to the state shown in FIG. 4.

First of all, paying attention to FIG. 1, capstans 1l13a, Jb, pinch rollers 4a+4b, and reel shafts 1a, lb are symmetrically arranged 61 on both sides of the exhaust head 20, respectively.
has been done. The gear stand shafts 3a, 3b have pinion gears 5a, 5b and flywheels 6a, 6b with a diameter of >4, respectively.
19, and further provided with rotating plates 7a and 7°b which are rotatable about the respective capstan shafts 3a and 3b.

At one end of each rotating plate 7a, 7b, large and small pieces of western army 8a, 8 are attached.
b; The rotation transmitting body consisting of 51'a and 9b is III 1
The shafts 10a and 10b are supported through eccentric circular cam surfaces 11a and 10b.
lb is formed, and pressing protrusions 12a, 12b are formed at the maximum radius part of each eccentric circular cam 7a, Zb, and the shaft ZOa
, 10b. Also, each rotating plate 7a
, 7b have bent pieces 13a, 13b at their other ends.

The pinch rollers 4a, (b is 1IllZ4a).

Support Z 5 a, 15 rotatable around 14bf
b, and is freely movable toward and away from the capstan shaft 3a. Further, each of the supports 15a, 15b is also provided with bent pieces 16a, 16b.

In the figure, 17 is a switching plate that can be slid left and right.
*Protrusions 18a, 18b; 19a, 19b are provided so as to sandwich the bent pieces 13 a e 13 b of *7b, and the bent pieces 16a of each of the supports 15a', 15b,
16b is inserted into the opening 20a.

20b is provided. Note that each opening 20a.

111 beveled edges 21a and 21b are provided in a part of 20b, and when the switching plate 17 moves to the right, the left beveled edge 2zbl is a bent piece of the left support 15b as shown in FIG. z
6bKlf; When the left pinch roller 4b is pulled away from the capstan shaft 3b and the switching plate 17 moves to the left, the right inclined edge 21af and the right support z and 5a are folded as shown in Figure 4. Slide it onto the bent piece 16a and pull the right pinch roller 4a away from the capstan #13a. The support bodies 15a, 15b are connected to each pinch roller 4a, 4b' (i7 capstan shaft 3a,
It is biased in the direction of being brought into pressure contact with 3b.

Further, near one end of the switching plate 17, there is provided a joint @@25 which can be articulately rotated between a pair of stopper pins 23 and 24 by the deployment spring 22. These articulating plates 25
The expansion spring 22 constitutes a pinch roller switching mechanism together with the switching plate 17. For example, when the switching plate 17 moves to the left and the articulated plate 25 rotates to a position exceeding the neutral point, the articulated Due to the reversing force of the plate 25, the switching plate 1
7 to the left, so that the right pinch roller 4a is separated from the capstan gill 3a.

Gears 8a and 8b, which are large and small and are integrated, forming the rotation transmitting body;
Among 9a and 9b, gear 1 with the larger diameter? a+8b meshes with small gears 5a, 5b which are integrated with capstan shafts 3a, 3b, and small diameter gears 9a, 9b mesh with reel shafts 2a, Zb.
It is configured to selectively mesh with the large floats 26a and 26b provided coaxially with the floats 26a and 26b. In addition, these gears 9a
, 26a, or gear 9b.

26b is controlled by the rotation of rotating plates 7a, 7b, both rotating plates 7a, 71) are connected to gears 9a, 9.
bf gear 26&, 26bKIm tension spring 2 in the matching direction
7a and 27b. However, the rotation of the rotation plates 7a and 7b is controlled by the left and right movement of the switching plate 17, and when one gear (for example, the right gear 9a) is meshing with the gear 26a, the other gear 9b is in mesh with the gear 26a. It is associated away from gear 26b.

Rotating members 28a, 28b that rotate together with the reel shafts 1a, lb are attached to a shaft common to the reel shafts 1a, lb, and the rotating members 28a, 28b include pin-shaped pressing biasing portions 29a,
29b is fixed. In addition, reel III J f
l, Zb, rotating members 28a, 28b, and the large float 26a.

A mechanism (not shown) is inserted between the reel shaft 1a and the reel shaft 1a, and the large gear 26af can be rotated even if the rotation of the reel shaft 1a is stopped.In this case, the friction mechanism causes slippage. It turns out.

In the figure, reference numeral 30 denotes a fixed plate, and cam followers 31a, 31b and presser auxiliary members 32a, 32b are rotatably supported on this fixed plate 3o.

The cam followers 31a, 31b have abutting portions 33a, 33b at the portions farthest from the fulcrum position, and pressure receiving portions 34a, 34'o located on the rotational orbits of the pressing and urging portions 29a, 29b, and the fulcrum position. Elastic piece 3 near the position
5a and 35b.

Further, the presser auxiliary member 32a is approximately L-shaped, and has -side 3.
6a, 36b f The axis 1oa is placed on the outside of the job, and the other side 37a.

37b is opposed to the elastic pieces 35a, 35b of the cam followers 31a, 31'b.

Next, the effect will be explained.

In Figure 1, the right pinch roller 4a is connected to the capstan shaft 3.
4113a, and the rotation of the capstan 4113a in the direction of the arrow is transmitted to the right reel shaft Za via the gears 5a, 8a, 9a+26a and a friction mechanism (not shown).

At this time, the rotational force of the reel shaft 1a is applied to the pressing biasing portion 29a.
The contact portion 33a of the cam follower 31& comes into sliding contact with the cam surface JZa. As long as the contact portion 33a is in sliding contact with the cam surface 11a in this manner, the contact portion 33a and the pressing protrusion 12a will not come into contact with each other.

It is now assumed that playback or recording is being performed while a tape is being wound around the right reel shaft 1a.

At this time, since the left reel shaft 1 b Id is on the slag unloading side, the suppression biasing portion 29b does not press the pressure receiving portion 34bf of the cam follower 31b. However, in this state, the left rotation transmitting body (gears 8b, 9b) has moved away from the large gear 26b and has moved to a position where it is not engaged with the reel +in+7b, and the shaft 1'Ob is attached to one side of the presser auxiliary member 32b. is being pressed. Therefore, the other side of the presser auxiliary member 32b comes to press the elastic piece 3sb2 of the cam follower 31b, and the presser auxiliary member 32b presses the cam follower 3 instead of the pressing biasing portion 29b.
The contact portion 33b of No. 1 is held in sliding contact with the cam surface 11b.

Next, when the tape is completely wound on the right reel, slipping occurs in the friction mechanism inserted between the large gear 26a and the reel QB71a, causing the reel shaft to slip. a stops. Therefore, the contact portion 3 that is in sliding contact with the cam surface ZZa
3a separates from the cam surface 11a at the point closest to the shaft 10a, and the pressing protrusion Z2a comes into contact with the contact portion 33a as shown in Figure @2. In this case, since the fulcrum of the cam follower 31a does not move, the rotation transmitting body, that is, the rotating plate 7a rotates against the spring 27a and separates the gear 9af from the large south wheel 26a. And with this, the large gear 26
The transmission of rotational force to a is cut off.

On the other hand, due to the rotation of the rotating plate 7a, the bent piece 13a of the rotating plate 7a presses the protrusion 19a of the switching plate 17 from the right side as shown in FIG. 3, and moves the switching plate Z7 to the left. . Along with this, the articulated plate 25 rotates clockwise while accumulating the deployment spring 22, and when the neutral point of the spring 22 is exceeded, the elasticity of the spring 22 acts in the direction of rotating the articulated plate 25. hand,
Switching lit: 17 i Move rapidly to the left.

At this time, the left inclined edge 2Zb of the switching plate 17 becomes unlatched to the support body 15b as shown in FIG.
(The right tilting edge 21a rotates the support 15a in the opposite direction, so the left pinch roller 4b comes into pressure contact with the capstan shaft 3b, and the right pinch roller 4a rotates the capstan shaft 3b.) 1ull 3 separated from a.

Further, the left rotation plate 7b is rotated clockwise by being pulled by the spring 27b, thereby causing the small gear 9b of the rotation transmission body to be aligned with the large gear 261:l.

Therefore, as shown in Fig. 4, the shape is opposite to t vt, and the left reel zb rotates in the winding direction, and the tape is wound on the left reel while being played or recorded. become.

〔Effect of the invention〕

As described above, according to the auto-reversing device of the cheap record according to the present invention, the attached parts such as the electromagnetic plunger are inaccessible, and therefore the structure is easily miniaturized. In addition, it does not disturb the balance of the flywheel, and detects the stoppage of the reel 'all' and pinches the roller 4'X!
*Since the tape 'J1g is activated, malfunctions will not occur even if the tape tension becomes temporarily strong at startup.

[Brief explanation of drawings]

FIGS. 1 to 4 are schematic configuration diagrams of an auto-reverse device in an example of Mizumoto 111j. 1a*1b...Reel axis, 2...Magnetic head, 3a
, 3b... Capstan shaft, '4ap4b... Pinch roller, 8a+8b-large gear, 9a, 9b... Small gear, Ila, Ilb... Eccentric circular cam surface, 12a,
12b...Press protrusion, 17...Switching plate (pinch roller switching mechanism), 29a, 29b...Press biasing part, 31
a, 31b... cam follower, 32a. 32b... Presser auxiliary member, 33a, 33b... Contact portion. Applicant's agent Patent attorney Takehiko Suzue Commissioner of the Patent Office Kazuo Wakasugi 1. Display of the case Japanese Patent Application No. 58-182835 2, Name of the invention Auto-reverse system for tape recorder 3, Person making the amendment Relationship to the case Patent applicant Tanashin Electric Co., Ltd. 4, Agent 6, Details subject to amendment , Drawing 7, Contents of amendment

Claims (1)

[Claims] The capstan shaft, pinch roller, and reel shaft are arranged symmetrically on the left and right sides of the magnetic head.1 The capstan shafts on both sides and one of the reel shafts are constantly driven to rotate, and the reel shaft is the same as the one that is rotating. An auto-reverse tape recorder that runs the magnetic tape in one direction by pressing the pinch roller on the side against the corresponding capstan shaft, and automatically switches the running direction of the magnetic tape when the magnetic tape is wound to the end. In the device, a pressing force is provided at an eccentric position of each reel shaft, and the capstan shaft is constantly rotated by the rotational force of each capstan shaft, and the rotational force is applied to the corresponding reel shaft via a friction mechanism. The reel shaft has a symmetrical rotation transmitting body, an eccentric circular cam surface and a suppressing protrusion provided around the rotation axis of each rotation transmitting body, and a contact portion in a part, so that the reel shaft rotates. During this time, each abutting part is urged by the pressing biasing part to slide into contact with each of the cam surfaces, and the abutting part is released from the pressing protrusion, and the reel shaft stops and the pressing biasing part slides. When the abutment part remains in a position rimmed from the cam surface due to the disappearance of the pushing force, the pressing protrusion comes into contact with the abutment part and moves the rotation transmitting body f+) to a non-engaging position with respect to the cam surface. When the symmetrical cam follower and each of the rotation transmitting bodies move to a non-coupling position with respect to the reel axis, the rotary transmitting body or a member supporting the rotation transmitting body presses the symmetrical cam follower and applies a biasing force to the cam follower in place of the suppressing biasing portion. When the auxiliary presser member that slides the contact part of the cam follower onto the cam surface and the rotation transmitting body move to the non-engaging position, the left and right pinch rollers move to the capstan +! An auto-reverse device for a tape recorder, comprising a pinch roller switching mechanism for switching toward and away from 'It.