JPH05157123A - Spring clutch device - Google Patents

Abstract

PURPOSE:To improve durability and operability as a spring extends in the axial direction and presses a ratchet member against an engagement member and contracts in the diametrical direction and tightens a rotor at the free time and works in reverse at the locked time. CONSTITUTION:When a drive shaft 16 is rotated and rotation of a ratchet member 21 is locked by a control means, a coil spring 41 contracts in the shaft direction, stops pressing of the ratchet member 21 against a head part 18a of a feed collar 18, expands in the diametrical direction and cancels tightening of a feed hub 31. Consequently, rotation of the drive shaft 16 is not transmitted to the feed hub 31 through the coil spring 41 and others and stops. At this time, an outer peripheral surface of the feed collar 18 does not make contact with the coil spring 41 and does not wear quickly, and constant periodical oiling is not required. When locking is cancelled, the coil spring 41 extends in the axial direction, presses a contact surface 22 of the ratchet member 21 against the head part 18a, contracts in the diametrical direction and tightens the feed hub 31. Consequently, rotation of the drive shaft 16 is surely transmitted through the coil spring 41 and others.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spring clutch device suitable for application to industrial equipment such as a printer feed device.

[0002]

2. Description of the Related Art First, a schematic structure of a printer to which a conventional spring clutch device is applied will be described with reference to FIGS.

In these drawings, reference numeral 1 denotes a printing section, which is composed of a platen 2 and a printing head (not shown). A feeding device 10 is a means for feeding the paper P to the printing unit 1.

Here, the feed device 10 includes a feed roller 11, a pinch roller 12, a transport roller 13,
14 and the drive unit 15 and the like. Specifically, the feed roller 11 and the pinch roller 12
Are formed so that the paper P can be nipped and conveyed.
The drive unit 15 is a means for rotationally driving the feed roller 11, and includes a drive shaft 16, a gear 17, a drive motor (not shown), a spring clutch device 51, and the like. Here, the drive shaft 16 has a gear 17
It is configured to be rotated by a drive motor via the above.

On the other hand, the spring clutch device 51 is means for selectively transmitting / blocking rotation of the drive shaft 16 to the feed roller 11, as shown in FIGS. 6 and 7, and includes a feed collar 52 and a coil. Spring 53
And a ratchet member 54. The feed collar 52 is fixed to the drive shaft 16 via a stop pin 59 or the like. The spring 53 has one end 53 a fixed to the feed roller 11 and the other end 53 a.
a front end portion 52 of the feed collar 52 fitted and engaged with the b
It is formed so that the rotation of the drive shaft 16 can be transmitted to the feed roller 11 by tightening a by elastic force.

Further, the ratchet member 54 covers the coil spring 53 and is put into a rotation lock and a rotation free state by a rotation control means (not shown) so as to prevent the coil spring 53 from being tightened to the feed collar 52 against an elastic force. It is formed so that both of them (52, 53) can be slid and released.

However, when the paper is fed using the above printer, the drive motor is driven and the drive shaft 16 is rotationally driven via the gear 17 and the like. Then, the ratchet member 54 is made rotation-free by the rotation control means and rotates in synchronization with the drive shaft 16, and transmits the rotation of the drive shaft 16 to the feed roller 11.

On the other hand, when printing, the rotation control means locks the rotation of the ratchet member 54. Then, the ratchet member 54 causes the coil spring 53 to move.
Of the feed collar 52 is released against the elastic force, and the two (52, 53) slide. As a result, the drive shaft 16 idles and the rotation of the feed roller 11 is stopped.

[0009]

In the spring clutch device 51 having the above structure, the feed collar 52 and the coil spring 53 are in sliding contact with each other while the paper is not being fed, but they are in sliding contact with each other. The time is generally long. Therefore, the sliding contact portion between the feed collar 52 and the coil spring 53 is apt to be worn out or seized early and its durability is likely to be deteriorated.

Therefore, conventionally, oil is applied to the sliding contact portion between the feed collar 52 and the coil spring 53 at regular intervals. To apply the oil, the clutch device 51 is disassembled one by one. It must be carried out, and maintenance is troublesome.

It should be noted that the transmission of rotation using an electromagnetic clutch
Although it may be considered to perform the disengagement, the electromagnetic clutch is generally expensive and large in size, and has a drawback that it is difficult to meet the current demands for downsizing and cost reduction.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a spring clutch device capable of reliably transmitting and interrupting rotation while improving durability and handleability.

[0013]

SUMMARY OF THE INVENTION The present invention is a spring clutch device for transmitting / disconnecting power from a drive shaft to a rotating body, the engagement member being fixed to the drive shaft and having a collar portion. A ratchet member disposed between the engaging member and the rotating body so as to be rotatable and displaceable in the axial direction, and rotation control means capable of selectively switching the ratchet member between a rotation-free state and a rotation-locked state. The ratchet member is provided so that one end of the ratchet member can be press-fitted into the rotating member and the other end of the ratchet member is not in contact with the outer peripheral surface of the engaging member, and the ratchet member can be pressed against the flange portion of the engaging member. A spring, the spring extends in the axial direction when the ratchet member is in a rotation-free state to press the ratchet member against the flange portion of the engaging member and contract in the radial direction to tighten the rotating body, Or When the ratchet member is rotationally locked, the ratchet member contracts in the axial direction to release the pressing relationship between the ratchet member and the engaging member and expands in the radial direction to release the tightening to the rotating body. Is characterized by.

[0014]

In the present invention, when the drive shaft is rotated in a predetermined direction and the rotation control means is used to lock the rotation of the ratchet member in that state, the spring contracts in the axial direction to cause the ratchet member to engage the flange portion of the engaging member. It stops pressing and is expanded in the radial direction to release the tightening on the rotating body. As a result, the rotation of the drive shaft is not transmitted to the rotating body via the spring or the like, and the rotation is stopped. At this time, since the outer peripheral surface of the engaging member does not come into contact with the spring, the engaging member or the like is not worn out or seized early.
Further, there is no need to refuel at regular intervals, and maintenance is unnecessary.

On the other hand, when the rotation lock state of the ratchet member is released to the free state, the spring extends in the axial direction to press the ratchet member against the flange portion of the engaging member and contract in the radial direction to rotate. Tighten your body.
As a result, the rotation of the drive shaft is reliably transmitted to the rotating body via the spring or the like, and the rotary shaft is rotated in synchronization with the drive shaft.

As a result, it is possible to reliably transmit and block rotation while improving durability and handleability.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

The spring clutch device according to this embodiment is applied to a feed device of a printer provided with a driving portion 15 and the like, and as shown in FIGS.
8), the ratchet member 21, the rotation control means 25, the rotating body (feed hub 31) and the coil spring 41.

The same components as those shown in FIGS. 6 to 8 are designated by the same reference numerals, and the description thereof will be omitted or simplified.

Here, the engaging member is fixed to the drive shaft 16 and has a flange portion. In this embodiment, the engaging member is the drive shaft 1 as shown in FIGS.
Feed collar 1 fixed to 6 via stop pin 19
It is formed from 8. The feed collar 18 has a collar portion 18a and a cylindrical outer peripheral surface 18b.

The ratchet member 21 is arranged between the engaging member (feed collar 18) and the rotating body (feed hub 31 in this embodiment) so as to be rotatable and axially displaceable. A contact surface 22 is formed on the end surface side of the ratchet member 21 facing the feed collar 18. Further, the ratchet member 21 has an engagement hole 23 formed therethrough.

The rotation control means 25 is formed so that the ratchet member 21 can be selectively brought into a rotation locked state or a rotation free state. In the present embodiment, the rotation control means 25, as shown in FIG. 5, a lever 26 that can be engaged with each tooth of the ratchet member 21, a spring 28 for engaging the lever 26 with the ratchet member 21, The lever 26 is configured to include an electromagnet 27 for separating the lever 26 from the ratchet member 21 against the elastic force of the spring 28. Where the electromagnet 27
When is excited, the lever 26 rotates clockwise and is positioned at the position shown by the chain double-dashed line in the figure, and the rotation lock state of the ratchet member 21 is released and the ratchet member 21 becomes free.
When the electromagnet 27 is demagnetized, the lever 26 is returned to the position shown by the solid line in the figure by the elastic force of the spring 28.
The rotation of the ratchet member 21 is locked.

On the other hand, the rotating body (the feed hub 31 in this embodiment) is connected to the feed roller 11 as shown in FIGS. 1 and 2, and is rotatably mounted on the drive shaft 16.

Furthermore, a spring (a coil spring 41 in this embodiment) is provided between the ratchet member 21 and the rotating body (feed hub 31), and one end portion (42) of the spring tightens the rotating body (31). The ratchet member 21 with the other end (43) not in contact with the outer peripheral surface (18b) of the engaging member (feed collar 18). It is provided so that it can be pressed. The terminal end 43a of the other end 43 of the coil spring 41 is fitted into the engagement hole 23 of the ratchet member 21 as shown in FIG. In addition, the coil spring 41
Has a coil inner diameter larger than that of the outer peripheral surface 18b of the feed collar 18 so as not to contact the outer peripheral surface 18b of the feed collar 18.

Here, the coil spring 41 extends in the axial direction when the ratchet member 21 is in a rotation-free state and presses the ratchet member 21 against the flange portion (18a) of the engaging member (feed collar 18) and the radial direction. When the ratchet member 21 is in the rotation lock state, the ratchet member 21 contracts in the axial direction to release the pressing relationship between the ratchet member 21 and the engaging member (18) and the radial direction. It is configured such that it is enlarged to the state where the tightening to the rotating body (31) is released. Moreover, the natural length, pitch p1, and spring constant of the coil spring 41 are selected so that the expansion / contraction amount is large.

Next, the operation will be described.

Drive shaft 1 by driving the drive motor
6 is rotated in the direction of arrow R via the gear 17 and the like, and when the rotation control means 25 is used to lock the rotation of the ratchet member 21, the coil spring 41 contracts in the axial direction to feed the ratchet member 21 to the feed collar. The pressing to the collar portion 18a of 18 is stopped, and it is expanded in the radial direction to release the fastening to the feed hub 31.

As a result, the coil spring 41 is attached to the feed hub 31 (and hence the feed roller 11).
The rotation of the drive shaft 16 is not transmitted via the above, and the rotation is stopped.

At this time, the outer peripheral surface 18 of the feed collar 18
Since b and the coil spring 41 do not come into contact with each other, the feed collar 18 and the like are not worn out early. Further, it is not necessary to refuel at regular intervals.

Next, by exciting the electromagnet 27 of the rotation control means 25 to release the rotation lock state of the ratchet member 21 and bring it to a free state, the coil spring 4
1 extends in the axial direction to press the contact surface 22 of the ratchet member 21 against the collar portion 18a of the feed collar 18 and contract in the radial direction to tighten the feed hub 31. As a result, the rotation of the drive shaft 16 is reliably transmitted to the feed hub 31 (and therefore the feed roller 11) via the coil spring 41 and the like, and the feed roller 11 is rotated in synchronization with the drive shaft 16.

According to this embodiment, however, the drive shaft 1
6, an engaging member (feed collar 18) fixedly provided with a flange portion (18a), and arranged between the engaging member (18) and the rotating body (foot hub 31) so as to be rotatable and axially displaceable. Ratchet member 21 and ratchet member 2 provided
The rotation control means 25 capable of selectively switching 1 into the rotation free state and the rotation lock state, the one end portion (42) is fitted to the rotating body (31) in a tightenable manner, and the other end portion (43) is engaged. A spring (coil spring 41) provided so as to be able to press the ratchet member 21 against the collar portion (18a) of the engaging member (18) in a state of not contacting the outer peripheral surface (18b) of the member (18).
And the spring (41) has a ratchet member 21.
In the rotation-free state, the ratchet member 21 extends in the axial direction to press the ratchet member 21 against the flange portion (18a) of the engaging member (18) and contracts in the radial direction to tighten the rotating body (31), and the ratchet member 21. Is contracted in the axial direction to release the pressing relationship between the ratchet member 21 and the engaging member (18) and expand in the radial direction to release the tightening to the rotating body (31) in the rotation locked state. With this configuration, transmission of rotation between the drive shaft 16 and the rotating body (31) is performed via the spring (41) or the like.

When the rotation is cut off, the spring (4
1) does not come into contact with the outer peripheral surface (18b) of the engaging member (18), the engaging member (18) and the like will not be worn out quickly and there is no need to refuel at regular intervals. No maintenance required. Furthermore, no noise is generated.

As a result, it is possible to reliably transmit and cut off power while improving durability and handleability.

In the above embodiment, the engaging member is formed by the feed collar 18 fixed to the drive shaft 16 by the stop pin 19, but the feed collar 18 may be formed integrally with the drive shaft 16. (In such a case, the stop pin 19 is unnecessary).

[0035]

According to the present invention, an engaging member fixed to a drive shaft and having a flange, and a ratchet disposed between the engaging member and the rotating body so as to be rotatable and axially displaceable. A member, a rotation control means capable of selectively switching the ratchet member between a rotation free state and a rotation lock state, one end of which is fitted to the rotor so that the rotor can be tightened, and the other end of which does not contact the outer peripheral surface of the engaging member. A spring provided so that the ratchet member can be pressed against the collar portion of the engagement member in a contact state, the spring extends in the axial direction when the ratchet member is in the rotation free state, and the ratchet member is engaged with the collar of the engagement member. And contracts in the radial direction to tighten the rotor, and contracts in the axial direction when the ratchet member is in the rotation-locked state to release the pressing relationship between the ratchet member and the engaging member and expand in the radial direction. Having a form to release the tightening of the rotating parts have been configured Te, it is possible to reliably transmit and interruption of power while improving durability and handling properties.

[Brief description of drawings]

FIG. 1 is a half sectional view showing a main part of an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a main part of one embodiment.

FIG. 3 is a diagram showing a form of a coil spring.

FIG. 4 is a diagram illustrating sheet feeding.

FIG. 5 is a diagram showing a state in which the ratchet member is brought into a rotation lock state or a rotation free state by using a rotation control means.

FIG. 6 is an overall configuration diagram showing a conventional spring clutch device.

FIG. 7 is an exploded perspective view for explaining details of a conventional spring clutch device.

FIG. 8 is a diagram showing a printer to which a conventional spring clutch device is applied.

[Explanation of symbols]

 16 Drive shaft 18 Feed collar (engaging member) 21 Ratchet member 31 Feed hub (rotating body) 41 Coil spring (spring)

Claims (1)

[Claims] 1. A spring clutch device for transmitting / disconnecting power from a drive shaft to a rotating body, comprising: an engaging member fixed to the drive shaft and having a collar portion; the engaging member and the rotating body. A ratchet member rotatably disposed so as to be displaceable in the axial direction, rotation control means capable of selectively switching the ratchet member between a rotation free state and a rotation lock state, and one end of the ratchet member A spring provided so that the ratchet member is pressably fitted and the other end thereof is in non-contact with the outer peripheral surface of the engaging member and is capable of pressing the ratchet member against the flange portion of the engaging member, When the ratchet member is in a rotation free state, the ratchet member extends in the axial direction to press the ratchet member against the flange portion of the engaging member and radially contracts to tighten the rotating body, and the ratchet member is In the roll-locked state, the ratchet member contracts in the axial direction to release the pressing relationship between the ratchet member and the engaging member, and expands in the radial direction to release the tightening to the rotating body. Spring clutch device.