JPS6215883Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a drive mechanism for a tape recorder, and particularly relates to an improvement in the drive mechanism that utilizes the driving force of a motor or the like to set various modes such as fast forwarding and rewinding.

In this type of tape recorder that uses the driving force of a motor to change modes between fast forward and rewind modes, a cam is usually used as a mechanical element that converts rotational motion into reciprocating motion. The driven lever that reciprocates is configured to position drive components such as gears in accordance with the swing width given by the peripheral shape of the cam. However, in conventional drive mechanisms, the movement of one cam only positions one part, so the total number of cams and driven levers must be increased to accommodate many mode settings. As a result, there was a limit to the ability to simplify the mechanism and reduce the number of parts.

The purpose of this invention is to provide a drive mechanism that can simplify the mechanism and reduce the number of parts by commonly using one cam and one driven lever for two mode settings. It is in.

To summarize this device, it focuses on the fact that changing the direction of rotation of the cam changes the operating mode of the driven lever, and is characterized by arranging a first gear and a second gear on either side of the driven lever which mesh with each other depending on the operating mode, so that either gear can be selected to mesh with the drive gear supported on the driven lever depending on the direction of rotation of the cam.

Examples of this invention will be described below with reference to the drawings.

The figures are structural diagrams of a fast-forward/rewind mechanism to which a drive mechanism is applied, which is an embodiment of this invention. Fig. 1 is in stop mode, Fig. 2 is in fast-forward mode, and Fig. 3 is in rewind mode. It shows.

In the figure, the supply reel stand 1 has a gear 1a coaxially connected to it.
and the supply reel stand 2 is coaxially connected to the gear 2a.
At the same time, the gear 2a is meshed with a fast forward drive force transmission gear 3 which transmits the drive force while changing the rotational direction of the drive gear, which will be described later. It is located. A pulley 4a attached to the rotating shaft of a motor 4 that serves as a drive source for the reel stands 1 and 2.
A belt 6 is stretched between the fast forwarding/rewinding pulley 5 coaxially connected to a drive gear, which will be described later, so that the rotational force of the motor 4 is constantly transmitted to the drive gear.

A worm gear 8 is attached to the rotating shaft of a motor 7 which is configured separately from the motor 4, and a cam gear 9 having a band-shaped cam piece 9a on the upper surface meshes with the worm gear 8.
A position detection rotary plate 10 having protrusions 10a and 10b on its periphery is coaxially connected to the position detection rotary plate 10.

The driven lever 11 driven by the cam piece 9a is
It is rotatably supported by a shaft 12 at approximately the center thereof, and a driven pin 11a that follows along the outer or inner wall surface of the cam piece 9a is attached to one end, and a return spring 13 is hung on the other end. .
Also, a pin 14 is provided near the other end of this lever 11.
The drive gear 15 is rotatably supported by.

Note that 16 and 17 are position detection switches, and the projections 10a and 10b serve as switch pressing pieces to detect the rotational position of the cam gear 9 and to control the drive of the motor 7.

Next, the operation of the fast forward/rewind mechanism section having the above structure will be explained.

First, when shifting from the stop mode shown in FIG. 1 to the fast forward mode, a forward rotation drive signal is supplied to the motor 7 by a control circuit (not shown). As a result, the cam gear 9 begins to rotate counterclockwise, and in accordance with this, the driven pin 11a slides along the inner wall surface of the cam piece 9a. That is, the driven lever 11
rotates clockwise about axis 12. The above operation, that is, the rotation of the cam gear 9 and the driven lever 11, continues until the protrusion 10b of the rotary plate 10 for position detection presses the switch 16 for position detection.
drive is stopped. FIG. 2 shows the state at this time, and as shown, the drive gear 15 and the transmission gear 3 are in mesh, forming a fast-forward mode.

To shift from the fast forward mode to the stop mode, a forward rotation drive signal is further supplied to the motor 7, and the cam gear is rotated until the protrusions 10a and 10b of the rotary plate 10 for position detection press the switches 16 and 17 for position detection, respectively. Rotate 9 counterclockwise. Then, the driven pin 11a is removed from the cam piece 9a, and the driven lever 11 is moved by the action of the return spring 13.
rotates counterclockwise about shaft 12 and returns to the original state shown in FIG. 1, forming a stop mode.

Next, the transition from the stop mode to the rewind mode is performed by changing the supply signal to the motor 7 into a reverse rotation drive signal. In this case, the cam gear 9 begins to rotate clockwise, contrary to the above case, and the driven pin 11a slides along the outer wall surface of the cam piece 9a. Therefore, the driven lever 11 is connected to the shaft 1.
2, and this rotation is stopped by stopping the supply of the drive signal to the motor 7 when the protrusion 10a of the position detection rotating body 10 presses the position detection switch 17. be done. FIG. 3 shows the state at this time, and shows that the drive gear 15 and the gear 1a are in mesh, forming a rewind mode state. In order to shift from the rewind mode to the stop mode, a reverse rotation drive signal is further supplied to the motor 7, and the protrusions 10a and 10b of the position detection rotary plate 10 press the position detection switches 16 and 17, respectively. Rotate the cam gear 10 clockwise until the Then, the driven pin 11a comes off the cam piece 9a, and the driven lever 11 rotates clockwise about the shaft 12 by the action of the return spring 13, returning to the original state shown in FIG. 1, forming the stop mode. .

As described above, if the rotation direction of the motor 7 is set to forward rotation, the motor moves from stop mode to fast forward mode, and when set to reverse rotation, the motor moves from stop mode to rewind mode, and further rotation continues in the same direction. Return to stop mode from those modes by In other words, the direction in which the cam gear 9 rotates determines the mode to which the mode shifts from the stop mode.

In this way, this invention has two mode settings and one
Since two cams and one driven lever that follow the cams are commonly used, and one mode can be selected depending on the direction of rotation of the cam, the individual cams and driven levers for setting each mode can be used in common. This has the advantage of reducing the number of parts and simplifying the mechanism, making it possible to further downsize and reduce costs.

In addition, in the above embodiment, the cam structure was such that a cam piece was provided in a band shape on the top surface of the cam gear, but it is needless to say that the structure is not limited to this.
For example, by making a normal eccentric cam integral with a gear and appropriately setting the cam peripheral shape and gear rotation angle, the driven lever rotates clockwise during fast forwarding, and counterclockwise during rewinding. It is also possible to perform an operation similar to that of the above embodiment so as to rotate.

[Brief explanation of the drawing]

The figures are structural diagrams of a fast-forward/rewind mechanism to which a drive mechanism is applied, which is an embodiment of this invention. Fig. 1 is in stop mode, Fig. 2 is in fast-forward mode, and Fig. 3 is in rewind mode. It shows. 1a... Gear (first gear), 3... Rapid forward drive power transmission gear (second gear), 7... Motor,
9a... cam piece (cam), 11... driven lever,
15... Drive gear.

Claims (1)

[Scope of utility model registration request] A drive wheel is supported between the first and second reel stands, a motor, and the two reel stands so as to be rotatable in clockwise and counterclockwise directions, and is pivotally supported at one end of the drive wheel. It consists of a driven lever that can be selectively engaged with the base, and a cam body that has an outer wall surface and an inner wall surface and is connected to the motor and can be rotated in first and second different directions. Depending on the direction of rotation, the outer wall surface or the inner wall surface is brought into sliding contact with the other end of the driven lever, and the driven lever is rotated in the clockwise or counterclockwise direction to move the driving wheel to the first or second reel. A drive mechanism for a tape recorder, characterized in that it is engaged with a base.