JPH0335743B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a front loading mechanism (device of a VTR main body) which is used as a cassette tape attachment/detachment mechanism for home video tape recorders (hereinafter referred to as VTRs) and the like. The present invention relates to a front loading mechanism for loading and unloading a cassette tape from the front, and particularly to a front loading mechanism that can take out a cassette tape from a VTR body with a stable and smooth ejecting operation.

[Prior Art] In general, the following structure is known as a structure conventionally employed as a front loading mechanism for a home VTR. FIG. 1 is a front view showing a schematic configuration of the front loading mechanism, FIG. 2 is an exploded perspective view showing the main parts thereof, and FIG. 3 is a side view showing the main parts. In FIG. 1, reference numeral 1 denotes a cassette tape, which is shown mounted in an inner box 2, either about to be loaded into a VTR body, or just taken out. The inner box 2 is configured to be movable along a guide groove 4 formed on a side plate 3, and the side plate 3 and the guide groove 4 allow the cassette tape 1 attached to the inner box 2 to be recorded and recorded inside the VTR main body. In order to guide the player to the playback operation position, it is formed into an "L" shape, consisting of a portion that extends approximately horizontally from the front side of the VTR main body to the rear, and a portion that extends approximately vertically downward from the rear end of that portion. The engagement between the inner box 2 and the guide groove 4 is achieved by inserting a first pin 5 protruding from the side wall of the inner box 2 into the guide groove 4.

Further, the driving means for moving the inner box 2 along the guide groove 4 includes an arm 6, a first gear 7, a second gear 8, a third gear 9, a worm wheel 11, Worm 14, drive motor 1
It is mainly composed of 5th magnitude.

The arm 6 has an elongated hole 22 formed in its longitudinal direction, and the first pin 5 is slidably engaged with the elongated hole 22. Further, the arm 6 is connected to the first gear 7
The inner box 2 is pivoted to move the inner box 2 along the guide groove 4.

Rotation is transmitted to the first gear 7 via second and third gears 8 and 9.

As shown in FIGS. 2 and 3, the third gear 9
A second pin 10 is provided upright on one end surface of the shaft at a position radially away from the axis. Also,
A worm wheel 11 is coaxially with the third gear 9.
The worm wheel 11 is provided with a
A window 12 is formed through which the second pin 10 described above is inserted. This window portion 12 is connected to the second pin 10
The worm wheel 11 is formed into a long hole extending in the circumferential direction so as to allow the worm wheel 11 to rotate by a certain rotation angle relative to the third gear 9 even if the worm wheel 11 is inserted therethrough. A scissor-shaped spring 13 is fitted on the common shaft 23 of the third gear 9 and the worm wheel 11, one end of which engages with the second pin 10, and the other end of which engages with the second pin 10. They are respectively locked to hook portions 24 protruding from one end surface of the worm wheel 11.

A worm 14 meshes with the worm wheel 11, and the worm 14 is attached to the output shaft of a drive motor 15.

On the other hand, a cam 16 is attached to the first gear 7, and a switch 1 that operates the drive motor 15 is connected to the first gear 7.
It is configured to rotate integrally with the first gear 7 to open and close the gear 7.

Therefore, in the front loading mechanism constructed as described above, when loading the cassette tape 1 into the VTR body, the cassette 1 is inserted into the inner box 2 and pushed into the VTR body. In response to this movement, the inner box 2 moves along the guide groove 4, and the first pin 5 rotates the arm 6. As the arm 6 rotates, the first gear 7 and the cam 16 rotate. The open/close position of the switch 17 is determined by the rotation angle of the cam 16 at this time. Further, the rotation of the first gear 7 is transmitted to the second and third gears 8 and 9, and the rotation of the third gear 9 is transmitted as an elastic strain of the scissor-shaped spring 13 via the second pin 10. Absorbed. When the cassette 1 and the inner box 2 are pushed into the VTR body by a predetermined amount, the switch 17 is closed, the drive motor 15 is activated, and its rotation is transmitted to the arm 6 via the gear train. The inner box 2 and cassette 1 are moved along the guide groove 4 via the pin 5 of 1. The cassette 1 is moved to a predetermined position and set to a recording/reproducing state.

On the other hand, when taking out the cassette tape 1 from the VTR main body, the drive motor 15 rotates in the opposite direction to that when it was installed, and the arm 6 also rotates in the opposite direction (first
(Rotate clockwise in the illustration). The cassette 1 moves along the guide groove 4 and is ejected from within the VTR body.

By the way, if we pay attention to the driving force transmission state between the third gear 9 and the worm wheel 11 when the cassette 1 is installed and taken out, it is found that when the cassette 1 is installed, the worm wheel 1 rotates counterclockwise in FIG. . Therefore, the second pin 10 is biased by the inner circumferential wall surface of the window portion 12, and the driving force is synthetically transmitted to the third gear 9. On the other hand, during removal, the worm wheel 11 rotates clockwise in FIG. 1. Therefore, the second pin 10 is biased by the elastic force of the scissor-shaped spring 13, and the driving force is transmitted to the third gear 9 elastically. For this reason, if a variation in frictional resistance occurs between the first pin 5 traveling in the guide groove 4 and the inner circumferential wall of the guide groove 4, the moving speed of the cassette 1 becomes uneven, making it difficult to take out the cassette stably. I couldn't do it. Particularly, the resistance increases at the bent portions of the guide groove 4, causing the problem that the above-mentioned tendency becomes more noticeable.

[Summary of the Invention] The present invention has been devised in view of the above-mentioned problems and to effectively solve them.

In this invention, the drive force transmission system is entirely constructed of a rigid transmission mechanism in the operation of taking out a cassette tape from the main body of a magnetic recording/reproducing device such as a VTR, and thereby the cassette tape can be taken out with stable and smooth operation. The purpose is to provide a front loading mechanism that can

[Embodiments of the Invention] A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 4 is a front view showing a schematic configuration of the front loading mechanism according to the present invention, FIG. 5 is an exploded perspective view showing the main parts thereof, and FIG. 6 is a side view showing the main parts. The respective figures are Fig. 1, which shows a conventional example;
This corresponds to FIG. 2 and FIG. 3, and therefore similar components are given the same reference numerals and redundant explanations will be omitted.

As shown in each figure, the third gear 9 and the worm wheel 11 have the same diameter and are coaxially provided. A portion of the outer periphery of the third gear 9 is cut out, and teeth have been removed. The rotation of the third gear 9 and the worm wheel 11 is restricted by a small gear 18 that meshes with each tooth. Although the pinion 18 has a fixed axis, it is free to rotate about the axis. Third
The position of the notch 25 of the gear 9 is the position of the notch 25 when the first pin 5 is in the horizontal part of the guide groove 4 when the first pin 5 is engaged with the guide groove 4, that is, when it is installed, When the first pin 5 is at the position reaching the bending part of the guide groove 4, the first pin 5 is
The cutout portion 25 is set to face the small gear 18 when the pin 5 is in a position after passing through the bent portion of the guide groove 4.

Next, the operation of this embodiment will be explained.

When installing the cassette tape 1 into the VTR body, when the cassette 1 is in the state shown in FIG. 4, that is, when it is about to be pushed into the VTR body, the notch 25 of the third gear 9 is At the same time, the small gear 18 is in mesh with the worm wheel 11. Cassette 1
is pushed into the VTR body and the drive motor 15 starts rotating, the rotation is caused by the worm wheel 11
The force is rigidly transmitted to the third gear 9 through the engagement between the window portion 12 and the second pin 10, as in the case of conventional mounting. At this time, the small gear 18 rotates with the rotation of the worm wheel 11, but is not meshed with the third gear 9. The pinion 18 and the third gear 9 mesh before the first pin 5 reaches the bent part of the guide groove 4, and the worm wheel 11, the third gear 9, and the pinion 18 rotate in synchronization. In this state, the worm wheel 11 is further driven, and the movement of the cassette 1 is continued until the mounting is completed. This state becomes the initial state at the time of extraction.

When taking out the cassette tape 1 from the VTR main body, the drive motor 15 rotates in the reverse direction, and its rotation is transmitted to the worm wheel 11 via the worm 14. In this state, the rotation of the worm wheel 11 is transmitted to the third gear 9 via the pinion 18, and therefore the driving force is rigidly transmitted between them. This rigid driving force transmission system is maintained until the first pin 5 passes through the bend in the guide groove 4, and when the first pin passes through the bend in the guide groove 4, the pinion 18 is transferred to the third pin. The engagement with the gear 9 is released, and the second pin 18 is thereafter driven by the urging force of the scissor-shaped spring 13 to complete the extraction operation.

[Effects of the Invention] As is clear from the above description, the present invention provides the following excellent effects.

In other words, in the operation of ejecting a cassette tape from the main body of a magnetic recording/reproducing device such as a VTR, the driving force transmission system is entirely constructed of a rigid transmission mechanism, so that the cassette tape can be ejected with stable and smooth operation. can.

[Brief explanation of drawings]

Fig. 1 is a front view showing a schematic configuration of a conventional front loading mechanism, Fig. 2 is an exploded perspective view showing the main parts thereof, Fig. 3 is a side view showing the main parts, and Fig. 4 is a front view according to the present invention. FIG. 5 is an exploded perspective view showing the main parts, and FIG. 6 is a side view showing the main parts. In the figure, 1 is the cassette tape, 2 is the inner box, and 3 is the cassette tape.
4 is a side plate, 4 is a guide groove, 5 is a first pin, 6 is an arm, 7 is a first gear as a driven side gear of a gear train, 9 is a third gear as a driving side gear of a gear train, 10 1 is a second pin, 11 is a worm wheel, 13 is a scissor-shaped spring as a spring member, 14 is a worm, 15 is a drive motor, 18 is a small gear, 25
is the notch.

Claims (1)

[Scope of Claims] 1. An inner box for holding a cassette containing a magnetic tape; a first pin protruding from a side wall of the inner box; and the first pin being engaged with each other. a side plate that clamps the inner box and is provided with a guide groove that guides and restricts the movement of the inner box; an arm that engages with the first pin and swings to drive the inner box; and a driven gear. a gear train that engages with the arm to transmit rotational driving force; a worm wheel that is rotatably attached to a rotation shaft of a driving gear of the gear train; and one of the driving gears. Protruding from the end face, engaging with the worm wheel to transmit the rotation of the worm wheel to the drive side gear, and allowing the worm wheel to rotate around the rotation axis within a predetermined rotation angle range. a second pin, one end of which is engaged with the worm wheel and the other end of which is engaged with the second pin, which urges the driving gear to move the inner box in the cassette removal direction; In the front loading mechanism of a cassette-type magnetic recording device equipped with a spring member, the drive side gear and the worm wheel are formed to have the same diameter, and a small gear is provided that meshes with the drive side gear and the worm wheel at the same time. . A front loading mechanism for a cassette type magnetic recording/reproducing device, characterized in that a notch is formed on the outer peripheral side of the drive side gear with teeth removed over a predetermined circumferential length range.