JPH0636515Y2 - Tape guide mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a tape guide mechanism used in reverse reproduction (REV) of a magnetic recording / reproducing apparatus such as a video tape recorder (VTR).

(B) Conventional technology In the so-called M-loading type VTR, during normal playback in the forward direction, the tape travels from the supply reel → the guide pole →
Back tension post → erasing head → impedance roller → cylinder → voice / control head → capstan → take-up reel. On the other hand, reverse playback,
That is, during reverse playback, the tape running is exactly opposite to that described above. Therefore, the winding height unevenness on the supply reel side during normal playback is absorbed by various members, but the tape winding height unevenness on the take-up reel side during reverse playback is directly transmitted to the capstan as tape height fluctuations, Tape running becomes impossible.

Therefore, in order to prevent the tape height from changing during reverse playback,
A technique for allowing a height-regulating tape guide to enter the tape running path only during reverse playback is disclosed in Japanese Patent Laid-Open No. 60-35365 (G1
1B15 / 665).

As shown in FIG. 6, the tape guide mechanism in the prior art described above has a columnar guide post (1) for height regulation in which upper and lower regulation flanges (1a) (1b) are fitted to the upper and lower ends.
Is erected at one end of the arm (2) and the other end of the arm (2) is caulked into a cylindrical resin boss (3) to integrate the three members, and the boss (3) is further attached to the chassis ( 4) is rotatably fitted to a metal support shaft (5) planted in 4), and is attached to the upper end of the support shaft (5) with a washer (7) as a stopper via a spacer (6). By fitting the coil spring (8) to the boss (3) so that it is located between the chassis (4) and the arm (2), the arm (2) is always biased upward by the coil spring (8), and the guide is guided. The vertical position of the post (1) itself is restricted.

The tape guide mechanism configured as described above is arranged on the take-up reel (11) side of the tape running system path as shown in FIG.
A slide plate (not shown) that slides according to the operation mode is connected to the arm (2) via a connecting mechanism (not shown). In FIG. 3, (12) is an impedance roller, (13) is an erasing head, (14) and (15) are leading guides, (16) and (17) are inclined posts, (18) is an A / C head,
(19) is a fixed guide, (20) is a captan, (21) is a pinch roller, (10) is a supply reel, (11) is a take-up reel, and (27) is a cylinder.

FIGS. 4 and 5 show the vicinity of the capstan in FIG. 3 in more detail. In FIGS. 4 and 5, (22) is a pinch roller drive lever, (23) and (24) are fixed guides in the cassette, and (25) is a notch provided in the cassette.

In modes other than reverse playback, for example, stop mode, the guide post (1) has a cassette notch (25) as shown in Fig. 4.
It is housed inside and does not separate from the tape to guide the tape, and the arm (2) rotates clockwise to the position shown in FIG. The height of the tape running path is regulated by contacting the guide post (1) between the flanges (1a) and (1b).

(C) Problem to be Solved by the Invention According to the above-mentioned conventional technique, the structure such as interposing the coil spring between the chassis and the arm is complicated, and the assembling work is also complicated. Further, the height of the tape guide mechanism itself on the chassis is increased by the length of the coil spring, which makes it difficult to thin the VTR itself.

(D) Means for Solving the Problems The present invention provides a fitting cylinder body disposed on a chassis and an annular groove that is fitted to the fitting cylinder body and engages with a hook portion in the fitting cylinder body. The rotary shaft comprises a rotary shaft, an arm whose one end is fixed to the rotary shaft, and a guide post which is installed at the other end of the rotary shaft. It is characterized in that a taper-shaped portion that abuts is formed.

In addition, a locking hook that defines the height direction of the arm tip is provided on the chassis at the operating position of the guide post.

Therefore, in the tape guide mechanism according to the present invention, when the taper-shaped portion is formed in the lower part of the annular groove, the hook portion and the taper-shaped portion elastically contact each other, so that the rotating shaft is rotated around the entire circumference. Is urged downward. In addition, when the locking hook is provided, the
The height direction of the arm tip is regulated by the engagement of the arm tip with the locking hook.

(F) Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 relate to the first embodiment, FIG. 1 is a partial sectional view, and FIG. 2 is an explanatory view of a main part. The same parts as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

A boss (fitting cylindrical body) (30) is outsert-molded on the lower surface of the chassis (4) using a resin having elasticity by utilizing the through hole (4a). The boss (30) has a cylindrical shape, and a thin hook portion (30a) is formed on the inner surface.

Reference numeral (31) is a metal rotation shaft rotatably fitted in the boss (30) from the upper surface side of the chassis (4), and an annular groove (32) is provided on the outer periphery of the lower end portion thereof, and a tip end thereof is provided with an annular groove (32). A head portion (33) is formed, and a first taper-shaped portion (33b) having a smaller diameter downward is formed in the lower portion of the head portion (33). A second taper-shaped portion (33a) (taper-shaped portion) having a larger diameter on the lower side is formed in the upper portion of the head portion (33) (the lower portion of the annular groove (32)), and the second taper-shaped portion ( The hook portion (30a) is engaged with the portion (33a) to regulate the upward position of the rotating shaft (31). Here, the elasticity of the hook portion (30a) causes the second taper-shaped portion (33a) to always receive a force in the horizontal direction (parallel to the chassis), so that the rotation shaft (31) itself and the hook portion (30a) are not separated from each other. Since there is no rattling and the second taper-shaped portion (33a) and the hook portion (30a) are in line contact rather than surface contact, it is difficult to affect the smooth rotation of the rotation shaft (31).

An arm (2) having a guide post (1) at its tip is fixed to the rotating shaft (31). At this time, the rotation axis (31)
While the hook portion (30a) and the second taper-shaped portion (33a) are engaged with each other to regulate the position of the rotating shaft (31) in the upward direction,
The length is set so as to be pulled upward by the arm (2). The guide post (1), the arm (2), and the rotary shaft (31) rotate integrally around the rotary shaft (31), and the guide post (1) only rotates during reverse rotation reproduction as in the conventional example. Comes into contact with the tape to regulate the height of the tape.

The boss (30) has elasticity, a split groove is provided at the lower end, and the first taper portion (33b) is formed at the tip of the rotating shaft (31). At times, it is easy to insert the rotary shaft (31) into the boss (30).

Next, a second embodiment will be described.

7 to 9 relate to the second embodiment, FIG. 7 is a partial sectional view, FIG. 8 is an explanatory view of main parts, and FIG. 9 is a plan view showing an operating state of an arm. The same parts as those in the conventional example and the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

(41) is a locking hook which is outsert-molded on the chassis (4). When the arm (2) rotates and the guide post (1) comes into contact with the tape and reaches the operating position that defines the height direction of the running tape, the tip portion (2a) of the arm (2) locks the hook (41). ) Is engaged. Due to this engagement, the position of the arm (2) in the height direction is accurately regulated in the operating position. When the tape comes into contact, the guide post (1) receives a force in the (A) direction, but since the position of the arm (2) in the height direction is accurately regulated, the guide post (1) is There is no displacement in the (A) direction.

Since the upper portion of the head portion (43) formed on the rotating shaft (31) does not constantly contact the hook portion (30a), it does not affect the rotation of the rotating shaft (31). Further, since the upper portion of the head portion (43) is not particularly formed in a tapered shape, it cannot easily come off even when an upward force is applied to the rotating shaft (31) due to strong vibration or the like.

(G) Effect of the Invention As described above, according to the present invention, the tape guide mechanism that requires height regulation can be realized with a simple structure without using a spring or the like, and the assembling work can be easily performed. effective.

[Brief description of drawings]

1 and 2 relate to the first embodiment of the present invention, FIG. 1 is a partial sectional view, and FIG. 2 is an explanatory view of a main part. 3 is an explanatory view of the tape running path, FIG. 4 is an explanatory view of the state of the tape guide in the stop mode, FIG. 5 is an explanatory view of the state of the tape guide in the REV mode, and FIG. 6 is a side sectional view of the conventional example. is there. 7 to 9 relate to the second embodiment, FIG. 7 is a partial sectional view, FIG. 8 is an explanatory view of main parts, and FIG. 9 is a plan view showing an operating state of the arm. (1) …… Guide post, (2) …… Arm, (2a)…
… Arm tip, (4) …… Chassis, (30) …… Boss (fitting cylinder), (30a) …… Hook part, (31) …… Rotating shaft, (32) …… annular groove, (33a) ... 2nd taper shape part (taper shape part, (41) ... locking hook.

Claims (2)

[Scope of utility model registration request] 1. A fitting cylinder body which is outsert-molded on a chassis and has a split groove at a tip portion, and a fitting cylinder body fitted in the fitting cylinder body, wherein the fitting cylinder body is provided in an annular groove on an outer periphery of a lower end portion. A rotation shaft for engaging the hook of the rotation shaft, an arm having one end fixed to the upper end of the rotation shaft and abutting on the upper surface of the fitting cylindrical body, and an arm that is planted on the other end of the arm and abuts on the tape to run. A tape guide mechanism comprising a guide post that defines the height direction of the tape, and a tapered portion that elastically abuts the hook portion is formed in the lower portion of the annular groove. 2. A fitting cylindrical body which is outsert-molded on a chassis and has a split groove at its tip, and a fitting cylindrical body fitted in the fitting cylindrical body, in an annular groove on the outer periphery of the lower end of the fitting cylindrical body. A rotating shaft that engages the hook, an arm that has one end fixed to the upper end of the rotating shaft and abuts on the upper surface of the fitting cylinder, and an arm that is planted on the other end of the arm and that abuts on the tape to move the running tape. A locking hook configured of a guide post that defines a height direction, and an engaging hook that defines a height direction of the arm tip portion is outsert-molded on the chassis at an operating position of the guide post. Tape guide mechanism.