JPH0118919Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a mechanism for obtaining a large oscillating force without increasing power loss in a gear oscillating mechanism that changes the destination of power transmission depending on the rotational direction of the drive system. Conventionally, in gear rocking mechanisms, as shown in FIGS. 1 and 2, a friction transmission mechanism is provided between a gear 1 and a lever 5 to obtain rocking force, and its slip force is utilized. When the oscillating gear 2 meshes with the driven gear 3 or 4, the friction transmission mechanism slips, and the force required for slipping results in a loss of driving force, so it is desirable that the force be small, and the oscillation due to frictional force should be kept small. The power is driven by the oscillating gear 2
Although it is desirable that this force be small, it has not been possible to set the friction force very small due to variations in component dimensions, burrs, and variations in the coefficient of friction. Also, depending on whether the oscillated gear 2 is meshed with the driven gear 3 or the driven gear 4, when switching a switch or moving a mechanical member, the transmitted power is We wanted to increase the slip force of the friction transmission mechanism and obtain a large swinging force at the expense of friction loss. As a result, the mechanisms and prime movers become larger, and in small equipment that uses batteries as a power source, power consumption increases, leading to larger batteries and an increase in the number of batteries, making it impossible to downsize the equipment. It was hot. Furthermore, with a friction mechanism, it is impossible to obtain a swinging force as large as the transmitted power. The present invention provides a swinging mechanism that is small, lightweight, and capable of reliably obtaining a large swinging force without such drawbacks. A detailed explanation will be given below based on examples.

FIGS. 3 and 4 show an embodiment of the present invention, which is a tape drive mechanism of a magnetic recording device. The pawls integrated with the driven gears 3 and 4 are configured to mesh with the pawls of the inserted cassette tape reel. Felt 1 is placed between gear 1 and lever 5.
4. A leaf spring 15 is inserted to form a friction transmission mechanism, and the pin 7 fixed to the lever 5 is slidably inserted into the hole of the lever 8, which is supported by pins 9 and 10. It's in. In the gear 6, the driven gear 2 is oscillated and the driven gear 3 is oscillated.
Or, it is provided so as to mesh with the pivoted gear 2 when it is not meshed with the gear 4. Lever 11
is part of the tension regulator, and spring 1
3, and the pin 12 fixed to the lever 11 hits the lever 8 to determine the degree. The oscillating gear 2 is rotatably attached to the lever 5 and is always meshed with the gear 1.

In FIG. 3, when the oscillating gear 2 is at the position 2a, it is meshed with the driven gear 3, and the magnetic recording device is in a normal rotation state. The tension regulator pulls the tape and provides back tension to the tape. When this state becomes reversed,
The gear 1 begins to rotate in the direction of the arrow in FIG. 3, the lever 5 to which the pivoted gear 2 and the pin 7 are attached begins to pivot, and after the pivoted gear 2 meshes with the gear 6, it reaches the position 7b. Pin 7 starts pushing lever 8.
By the time the lever 11 is pushed by the lever 8 and reaches the position 11', the tension regulator is separated from the tape and does not apply unnecessary force to the tape during reverse rotation.
When the pin 7 reaches the position 7c, the lever 8 has already pushed up the lever 11, so the force from the spring 13 is mainly applied to the pins 9 and 10,
Swinging from the position to the position 7d only requires a small swinging force. As described above, by providing the gear 6 that meshes with the driven gear 2 when the driven gear 2 is oscillated and is not meshed with any driven gear, the slip force of the friction transmission mechanism can be reduced. It is possible to reliably obtain a large swinging force regardless of the situation. In other words, since the gear 2 and the gear 6 mesh with each other to ensure reliable oscillation, the slip force of the friction transmission mechanism can be small, and the influence of variations in the slip force is small, so the oscillation mechanism can be made smaller. be. Furthermore, since the slip force is small, there is little loss of transmitted power, and the horsepower of the prime mover and power consumption can be reduced if it is a motor, so the size and weight of the prime mover, power source, etc. can be reduced. In addition, since the rocking force in the mechanism of the present invention is as large as the transmitted power, it is possible to perform tasks such as moving other members or switching switches during rocking without using any other power source. I can do it.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a conventional example, Fig. 2 is a sectional view showing the conventional example, Fig. 3 is a plan view of an embodiment of the present invention, and Fig. 4 is a sectional view of an embodiment of the present invention. be. 1 is a gear, 2 is a swinging gear, 3 and 4 are driven gears, 5 is a swinging lever, 6 is an internal gear, 7 is a pin for transmitting the swinging force, and 8 is for transmitting the swinging force to other members The lever 11 for this purpose is a mechanical member that is moved by rocking force. 2a, 2b, 2c, 2d,
2', 7a, 7b, 7c, 7d, 8' and 11' indicate the states when the pivoted gear 2, pin 7, lever 8, and lever 11 have moved, respectively.

Claims (1)

[Scope of utility model registration request] A gear 1, a lever 5 that is rotatably provided coaxially with the rotation axis of the gear 1, and a pivoted gear that is rotatably provided on the gear 1 and the lever 5 and meshes with the gear 1. 2, a driven gear 3, and a driven gear 4, the lever 5 is swung via the friction transmission mechanism according to the rotational direction of the gear 1, and the swung gear 2 is swung. In the gear rocking mechanism that selectively transmits power to the driven gear 3 or the driven gear 4, the gear 6 is fixed to the rotating shaft of the gear 1.
In addition, the gear 6 is configured such that when the pivoted gear 2 that is being pivoted is in a position where it does not mesh with either the driven gear 3 or the driven gear 4, the pivoted gear 2 and the gear 6 are A gear rocking mechanism characterized by being provided at a position where they mesh.