JPS6129148Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic return mechanism used for opening and closing switches and the like. Conventionally, the above-mentioned return mechanism is as follows:
Many models use torsion coil springs, but this type of automatic return mechanism may be inappropriate and cannot be used due to constraints such as shape, and automatic return mechanisms that use torsion coil springs are , when applying torque in the forward direction,
It performs the desired predetermined action and returns easily, but if used in a manner that applies torque in the opposite direction, there is a risk that the coil spring may break and the predetermined action may not occur and return reliably. There was something inappropriate about it. Therefore, for example, when limit switches are installed in symmetrical positions, the limit switches are opened and closed with one pusher, and the external force applied to the pusher is removed, the pusher automatically returns to its original equilibrium point. In this case, an automatic return mechanism using a torsion coil spring is not appropriate.

The present invention relates to an automatic return mechanism devised to improve this point, in which a single flat cam-shaped push piece can be rotated to symmetrical positions, for example left and right, by a drive shaft, and the above-mentioned rotation An operating shaft, which is fitted into a moving cam-like push piece and held by holders on both sides of the automatic return mechanism, is elastically supported by a spring on the holder, and the operating shaft is supported against the elastic force of the spring. , rotate the switch by a predetermined angle to open and close the switch,
When the external force is removed, the above spring returns,
The cam-like push piece is automatically returned to its original position easily and similarly from any symmetrical position.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 3 show a first embodiment of the present invention, in which 1 is a casing of an automatic return mechanism according to the present invention, which is formed in a U-shape, with holders 2, 2 on both sides of the casing at the bottom. The holder 2 is provided so as to stand upright from the holder 2, and a cam-shaped push piece 3 is interposed between the holders 2 and 2. A D-shaped drive shaft 4 is fixed to the lower part of the cam-like pusher piece 3, and the drive shaft 4 is inserted into bearing holes 5, 5 provided at the lower part of the holders 2, 2 and is mounted thereon.

Arc-shaped guide holes 6, 6 are formed in the upper portions of the holders 2, 2 in order to limit the rotation of the cam-shaped push pieces 3. An operating shaft 7 is fitted into the guide holes 6, 6, and the operating shaft 7 is further fitted into a bearing hole 3a formed in the upper part of the cam-shaped push piece 3.

Therefore, when the drive shaft 4 is rotated by an external force, the cam-like pusher piece 3 rotates around the drive shaft 4, and the actuating shaft 7 fitted into the cam-like pusher piece 3 moves through the guide holes 6, 6.
6a, 6b, 6c
It is stopped at each position. That is, the stop at point 6a is a stop at an equilibrium point in left and right rotation, point 6b is a stop point for right rotation, and point 6c is a stop point for left rotation. Reference numerals 8 and 8 indicate return springs for automatically returning the cam-like pusher piece 3 to the above-mentioned equilibrium point when the cam-shaped pusher piece 3 is rotated. An elastic suspension is placed between them, and the actuating shaft 7 is elastically moved toward the hook pieces 2a, 2a. Reference numerals 9 and 9 designate limit switches fixed to the device that uses the automatic return mechanism according to the present invention, and are provided on both sides of the cam-like push piece 3 so as to be opened and closed by the rotating cam-like push piece 3.

FIG. 2 is a side view showing a case where the automatic return mechanism according to the present invention is stopped at the equilibrium point 6a, and the operating shaft 7 is sprung upward by the spring 8 and stopped at the equilibrium point 6a. . Now, when the drive shaft 4 is rotated clockwise by an external force, the cam-shaped pusher piece 3 fixed to the drive shaft 4 rotates clockwise, and the operating shaft 7 fitted to the pusher piece 3 is moved by the return spring. 8 along the guide hole 6, the return spring 8 is tensed as shown in 8a, and the cam-like push piece 3 opens and closes the right limit switch 9 to turn off the power and release the external force. Then, the return spring 8 returns to the operating shaft 7 again.
returns to the original equilibrium point 6a and stops. Next, when the drive shaft 4 is rotated to the left by an external force, the cam-shaped push piece 3 is similarly rotated to the left, and the operating shaft 7 is also moved to the left against the return spring 8, so that the return spring 8 is tensioned as shown in 8b. However, when the left limit switch 9 is opened and closed to release the external force, the return spring 8 returns, and the operating shaft 7 returns to its original position, the equilibrium point 6a. In this way, in order to control the left and right rotation of the operating shaft 7, that is, the cam-shaped push piece 3, to stop it, and to automatically return it to the equilibrium point 6a,
Coil springs 8, 8 are elastically suspended between both ends of the operating shaft 7 and the cut and raised heads 2a, 2a of the holders 2, 2. Then, the spring 8 is connected to the equilibrium point 6 of the operating shaft 7.
If an elastic suspension is placed between the side end corresponding to a and the hook piece directly above it, the cam-shaped push piece 3 will be pulled back to its original position in the same way even if it is rotated in either the left or right direction. can be carried out reliably and easily.

Other embodiments of the present invention are shown in FIGS. 4 and 5. In this embodiment, the guide hole 10 for rotating the operating shaft provided in the holder is formed into an inverted V-shape, whereas it is an arc-shaped groove in the previous embodiment. A long hole 11 into which the operating shaft 7 is inserted is provided on the upper part of the cam-shaped pusher piece 3 of the same size as the previous example, and the operating shaft 7 is inserted into the cam-like pusher piece 3,
It is inserted into the inverted V-shaped guide holes 11, 11 of the holders 2, 2, and elastically supported by the hook pieces 2a, 2a by the spring 8. When the drive shaft 4 is rotated to the right by an external force, for example, the cam-shaped push piece 3 is also rotated to the right. Accordingly, the operating shaft 7 moves along the inverted V-shaped guide hole 10 and simultaneously moves downward in the long hole 11 to tension the spring 8 as shown at 8c, opening and closing the right limit switch 9. In this case, if the same limit switch as described above is operated by a cam-like pusher piece of the same size, the clockwise rotation angle will obviously be smaller in terms of the movement of the cam-like pusher piece 3 shown in Fig. 5. . Then, when the cam-like pusher piece 3 rotates counterclockwise and the left limit switch 9 is operated in the same way, the left rotation angle of the cam-like pusher piece 3 is also small, as in the case of clockwise rotation. 2, 2 can be formed narrowly, and as a result, an automatic return mechanism used in a switch or the like can be constructed compactly.

In the case of this embodiment as well, since the spring 8 is tensioned only in the direction shown by 8c, the operating shaft 7 and the cam-shaped push piece 3 can be rotated in either left or right direction without fail. Can be returned to position. In this embodiment, not only can the automatic return mechanism be constructed compactly, but also the first
The limit switch can be opened and closed within a shorter time than in the embodiment described above.

In the automatic return mechanism according to the present invention, the return spring that elastically tensions the operating shaft is only tensioned in the coil winding direction, regardless of whether the cam-shaped push piece is rotated in the left or right direction. Because of this, the cam-like push piece can always be reliably and easily returned to the equilibrium point of its rotation automatically by the restoring force of the spring without causing any unreasonableness in its usage. The automatic return mechanism is
The structure is simple, the switch can be opened and closed reliably, and there is no risk of malfunction.

[Brief explanation of drawings]

FIG. 1 is a side view of the automatic return mechanism according to the present invention, FIG. 2 is a front view of the automatic return mechanism as seen from AA, and FIG. 3 is a diagram illustrating the relationship between the cam-shaped push piece and the switch as seen from BB. FIG. 4 is a front view of another embodiment of the present invention, and FIG. 5 is a diagram illustrating the relationship between the cam-like push piece and the switch in that case. 1... Housing frame, 2, 2... Holder, 3... Cam-shaped push piece, 4... Drive shaft, 6... Guide hole, 7... Operating shaft, 8... Return spring, 9... Limit switch, 10... Guide hole, 11... Long hole.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A drive shaft having a cam-shaped push piece fixed thereon is provided between the lower parts of the holders on both sides of the U-shaped housing frame in the automatic return mechanism, and An operating shaft parallel to the drive shaft is provided, and an arc-shaped operating shaft guide is provided on the side surface of the holder so that the cam-shaped push piece can rotate together with the operating shaft around the drive shaft in response to rotation of the drive shaft. A hole is provided, and a coil spring is made to spring between the end of the operating shaft and the cut-and-raised part of the holder head, and when the switch is opened and the drive shaft is stopped by rotating the cam-shaped push piece, the An automatic return mechanism characterized in that the cam-shaped push piece can be automatically returned to its original position by a coil spring. (2) Utility model registration claim 1, characterized in that the bearing hole of the operating shaft provided in the cam-shaped pusher piece is an elongated hole, and the guide hole provided in the holder is in an inverted V-shape. Automatic return mechanism as described.