JPH0227218Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention is based on the frictional force of a coil spring wound in a tightened state between a driving core and a driven core that are provided adjacent to each other on the same axis. The present invention relates to a spring clutch in which power is transmitted from a driving core to a driven core, and the transmission of power is released as the tightening force decreases.

BACKGROUND OF THE INVENTION Spring clutches are often used because of their simple construction when repeatedly transmitting power from a drive shaft that rotates at a constant speed on and off, causing the driven shaft to rotate at a constant angle and then stopping.

The configuration of an example of a known spring clutch is shown in the fifth example.
To explain with reference to the figure, a drive core 3 that is rotatably supported on a driven shaft 1 and has a pulley or sprocket 2 at one end driven by a drive source, and a driven core fixed to the driven shaft are adjacent to each other. The coil spring is wound tightly across the outer circumferential surfaces of both cores 3 and 4 with no external force acting on the coil spring. A sleeve-shaped cam member 6 is provided outside the coil spring 5 with a slight gap surrounding both cores, and one end of the coil spring is hooked to the driven core 4, and the other end is hooked to the driven core 4. It is hooked to the cam member. As shown in FIG. 6, the cam member 6 is provided with constant intervals in the circumferential direction, e.g.
Positioning protrusions 7 of the same shape are formed at 180 degrees apart, and by engaging and disengaging the positioning member 9, which is displaced by turning on and off the solenoid 8, the rotation of the cam member 6 is restrained and released, and the cam member When the rotation of the spring 5 is restricted, the friction between the rotating drive core 3 and the spring 5 causes the spring 5 to be twisted in a direction in which its diameter increases, resulting in a decrease in frictional force and slippage, cutting off power transmission. . Positioning plate 9
When the cam member is disengaged from the protrusion 7, the cam member is free to rotate, and the spring 5 is no longer twisted and its diameter is reduced to tighten the driving core 3 and the driven core 4, and the driving force is transmitted by frictional force.

With the above type of spring clutch, in order to rotate the stopped driven shaft by a predetermined angle, for example 180 degrees, the solenoid can be energized in a very short pulse in order to engage one of the engaging parts. The positioning member and the cam member are disengaged, the positioning member slides into contact with the cam member again, and when the cam member rotates, for example, 180 degrees, it catches on the other engaging part and the cam member stops, cutting off the power transmission. .

By the way, for example, in the end face folding mechanism of a paper folding machine, when paper is sent, a "spatula" is pushed out into the paper transport path at a certain timing from the side with respect to the transport direction of the paper, and after a certain period of time, the above-mentioned " The spatula is pulled back to the standby position, but when reciprocating the member at a fixed timing like this, it is necessary to connect the reciprocating member via a connecting rod to an arm attached to a shaft that rotates in one direction. Rotary motion can be converted into reciprocating motion. In the case of the above-mentioned paper folding device, the "spatula" must always perform the above operations from the standby position, but when using a spring clutch with the above configuration, it is necessary to move the spatula from the standby position to the operating position. or when returning from the operating position to the standby position, simply energizing the solenoid for a short time turns the solenoid off in both the standby and operating positions, indicating which position the spatula is currently in. I don't know if there is. In particular, if a power outage occurs during operation, there is a possibility that the next operation will start from the operating position.
This may cause malfunction.

In view of the above-mentioned problems with conventional spring clutches, the present inventor first proposed a spring clutch that rotates in 180° increments and that has a simple configuration and allows one to easily determine at which rotational position the driven shaft is stopped. did.

The outline is that the cam member of the conventional spring clutch explained in Figs. 5 and 6 is
For example, as shown in FIG. 7, two positioning members are provided 180 degrees apart, one protrusion 17a has the same shape as the conventional one, and the other protrusion 17b has an L-shaped cross section with one toe attached to the cam member. When the solenoid is in the OFF state, the positioning member is locked to the rotating protrusion 17a, and the protrusion The protrusion 1 escapes from 17b and the positioning member rotates when the solenoid is on.
The two protrusions are shaped so that they are locked to the protrusion 7b and escape from the protrusion 17a.

With this configuration, the rotational position of the driven shaft can be immediately determined depending on whether or not the solenoid is energized.

By the way, when a paper jam occurs in a paper folding machine, copying machine, etc., the power is turned off and the jammed paper is pulled out in the opposite direction to the paper passing direction to remove it. The member must be freely reversible.

However, in the case of a spring clutch equipped with a protrusion of the shape illustrated in FIG. 7, when the solenoid is turned off, the engagement member moves once from the state where it is engaged with the side surface of one protrusion, and the engagement member moves away from that protrusion. Since it comes into contact with the opposite side, it can only rotate one rotation at most, making it difficult to remove paper jams.

Purpose The present invention provides a simple structure which eliminates the above-mentioned drawbacks of the previously known spring clutch and the disclosed embodiment of the spring clutch previously proposed by the present inventor, and provides a mechanism for stopping the driven shaft at any rotational position. It is an object of the present invention to provide a spring clutch that rotates in 180° increments and allows the driven shaft to be easily reversed when the power is turned off.

Configuration In order to achieve the above object, the present invention provides a spring clutch having the configuration previously proposed by the present inventor, in which the above two positioning protrusions are
The flange provided on the outer periphery of one end of the cam member has the same thickness on both sides, and the engaging portion of the positioning member to the positioning protrusion is equal in thickness to the thickness of the flange and the thickness of one positioning protrusion. It has a U-shape with a recessed part with an opening width slightly larger than the width of the recessed part, and one side surface of both sides of the recessed part engages with the side surface of one of the positioning protrusions when the cam member rotates normally. of the positioning protrusion formed above,
The side surface on the side that approaches the positioning member when the cam member is reversed is characterized by an inclined surface that deflects the positioning member away.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, and the same members as in the conventional device are given the same reference numerals.

In this embodiment, the cam member 26 has two protrusions 27 provided at positions 180° apart from each other in the circumferential direction.
As shown in FIGS. 1 and 2, a and 27b are provided with the same thickness on both sides of a flange 26a that projects radially outward on the end surface of the cam member 26. As shown in FIG. 3, the positioning member 29 is formed as a magnetic elastic plate whose lower end is fixed to the frame of the solenoid 8, and whose upper end is partially bent into a U-shape to form an engaging portion 29a. . The engaging portion 29
The opening width of the recessed portion a is equal to the width of the flange 2 of the cam member 26.
The dimension is slightly larger than the sum of the thickness of the protrusion 6a and the thickness of one protrusion 27a or 27b.

FIG. 1 shows the solenoid 8 in the on state. In this state, the flange 26a of the cam part and the protrusion 27a
The protrusion 27 can pass through the U-shaped recess of the positioning member 29 and rotate.
When b rotates in the forward rotation direction, it engages with the side surface of the bent portion of the engaging portion 29a and restricts the rotation of the cam member 26.

FIG. 4 shows the state when the solenoid 8 is off, and the elasticity of the positioning member 29 itself causes the engagement portion 2 to
9a occupies a position to the right away from the solenoid 8, and the protrusion 27a rotating in the normal rotation direction engages to restrain the rotation of the cam member, and the protrusion 27b engages with the recessed portion of the engaging portion 29a. You can pass through it and turn.

As shown in FIG. 2, the shapes of the protrusions 27a and 27b are such that when the cam member is reversed, the positioning member engaging portion 29
The side surface approaching a is an inclined surface with an appropriate inclination. Therefore, the cam member 26
When reversely rotates, when the engaging portion 29a comes into contact with the protrusion that engages during forward rotation, its slope causes
It is easily deflected against the elasticity of the positioning plate 29,
The protruding portion can pass through the recessed portion of the engaging portion 29a. Therefore, when removing a paper jam in the opposite direction to the paper passing direction, the driven shaft can be easily reversed. The other functions are the same as those of the previously proposed device, so the explanation will be omitted.

Effects As described above, according to the present invention, it is possible to rotate the driven shaft in 180° increments and stop it with a simple configuration, and the rotational position at which it has stopped can be easily determined, and it is also useful when removing paper jams, etc. The driven shaft can be easily reversed.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the solenoid-on state of the embodiment of the present invention, Fig. 2 is a perspective view of the end of the cam member, Fig. 3 is a front view of the positioning plate, and Fig. 4
5 is a sectional view showing the configuration of an example of a conventional spring clutch, FIG. 6 is a perspective view showing the end of the cam member, FIG. 7 is a perspective view showing the end of the cam member of the previously proposed spring clutch, and FIG. 8 is a side view illustrating its function. 1... Driven shaft, 3... Drive core, 4... Driven core, 5... Coil spring, 8... Solenoid, 26... Cam member, 27a, 27b... Positioning protrusion, 29... Positioning plate, 29a ...Engagement part.

Claims (1)

[Scope of utility model registration request] A coil spring is tightly wound around the outer peripheral surfaces of both the driving core and the driven core, which are provided coaxially adjacent to each other, and one end of the coil spring is hooked to the driven core, and the other end is hooked to the driven core. A, which is hooked to a sleeve-like cam member that surrounds the core with a gap therebetween, and is disposed at one end of the cam member at a distance of 180° in the circumferential direction.
B Two positioning protrusions are provided, and a positioning member is provided that is displaced when the solenoid is turned on and off. When the solenoid is off, the positioning member engages with the A protrusion that rotates in the forward direction, and escapes from the B protrusion. , when the solenoid is in the on state, the positioning member engages with the B projection that rotates in the normal rotation direction, but sets the position shape of both projections so that it escapes from the A projection, and the positioning member is connected to either of the positioning projections. The rotation of the cam member is restrained and released by engaging and disengaging the cam member, and in the restrained state, the inner diameter of the coil spring expands and the tightening force against the outer peripheral surface of the driving core is reduced, thereby transmitting power from the driving core to the driven core. In the spring clutch, the coil spring tightens both cores when the cam member is released and the friction force transmits power from the driving core to the driven core. The protrusions are each provided with the same thickness on each of both sides of a flange provided on the outer periphery of one end of the cam member, and the portion of the positioning member that engages with the positioning protrusion has the same thickness as the flange. It has a U-shaped recess with an opening width slightly larger than the sum of the thickness of the projection, and one side of both sides of the recess is the side of one of the positioning projections when the cam member rotates normally. The spring clutch is formed to engage with the positioning member, and the side surface of the positioning protrusion that approaches the positioning member when the cam member is reversed is an inclined surface that deflects the positioning member to escape. .