JPH04357333A - clutch mechanism - Google Patents

Abstract

PURPOSE:To improve the durability and operability, and transmit and cut the rotation securely. CONSTITUTION:Grooves 33 of a rotating body 31 side are inclined to the rotation transmitting direction against grooves 23 on a latched member 21 side. Round shaft members 41 are rotatably inserted for connection into the mutually facing grooves 23, 33 of the latchet member 21 and the rotating member 31 so that the rotating body side engagement length l1 is equal to or less than the latchet member side engagement length L2.

Description

[Detailed description of the invention]

0001

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

0002

[Prior Art] First, the schematic structure of a printer to which a conventional spring clutch mechanism is applied is shown in FIGS. 10 to 12.
The explanation will be based on.

[0003] In these figures, numeral 1 denotes a printing section, which is composed of a platen 2, a printing head (not shown), and the like. A feed device 10 is a means for feeding the paper P to the printing section 1.

[0004] Here, the feed device 10 includes a feed roller 11, a pinch roller 12, a conveyance roller 13,
14, a driving section 15, and the like.

Specifically, the feed roller 11 and the pinch roller 12 are formed so as to be able to nip and convey the paper P. Further, the drive unit 15 is a means for rotationally driving the feed roller 11, and the drive shaft 16
, a gear 17, a drive motor (not shown), a spring clutch mechanism 51, and the like. Here, the drive shaft 16 is configured to be rotated by a drive motor via a gear 17 or the like.

Further, as shown in FIGS. 10 and 11, the spring clutch mechanism 51 is a means for selectively transmitting and interrupting rotation from the drive shaft 16 to the feed roller 11, and includes a hub 52 and a spring 53. and a ratchet member 54.

The hub 52 is fixed to the drive shaft 16 via a spring pin 59 or the like. In addition, the spring 53
is the tip portion 5 of the hub 52, which has one end 53a fixed to the feed roller 11 and is fitted and engaged with the other end 53b.
2a is elastically tightened to transmit the rotation of the drive shaft 16 to the feed roller 11.

Further, the ratchet member 54 is placed in a rotation-locked and rotation-free state by a ratchet control means (not shown) that covers the spring 53, and releases the tightening of the spring 53 against the hub 52 against the elastic force. Both (52, 53) are formed to be able to slide.

[0009] When the above printer is used to feed paper, the drive motor is driven and the drive shaft 16 is rotated via the gear 17 and the like. The ratchet member 54 is made free to rotate by the ratchet control means, rotates synchronously 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 of the ratchet member 54 is locked by the ratchet control means. Then, the tightening of the spring 53 against the hub 52 is released by the ratchet member 54 against the elastic force, and both (52, 53) slide. As a result, drive shaft 1
6 idles, and the rotation of the feed roller 11 is stopped.

[0011]

By the way, in the spring clutch device 51 having the above structure, the hub 52 and the spring 53 are in sliding contact while the paper is not being fed, but the time during which they are in sliding contact is Generally long. Therefore, the sliding contact portion between the hub 52 and the spring 53 is likely to wear out or seize early, resulting in a decrease in durability.

Therefore, conventionally, the hub 52 and the spring 53
Although it is common practice to apply oil to the sliding contact portion at regular intervals, the clutch device 51 must be disassembled each time the oil is applied, resulting in the inconvenience that maintenance is time-consuming. In addition, an electromagnetic clutch is used to transmit rotation.
Although it is possible to disconnect the clutch, electromagnetic clutches are generally expensive and large, and have drawbacks that make it difficult to meet current demands for miniaturization and cost reduction.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a clutch mechanism that can reliably transmit and interrupt rotation while improving durability and ease of handling.

[0014]

[Means for Solving the Problems] The present invention transmits the rotation of a drive shaft to a rotating body by setting a ratchet member in a rotation-free state, and by setting the ratchet member in a rotation-locked state, the rotation of the drive shaft and A clutch mechanism for separating the ratchet member from the rotary body, wherein a plurality of grooves are formed in the hollow cylindrical portion of the ratchet member along the inner circumferential direction, and the same number of grooves are formed in the hollow cylindrical portion of the rotating body along the inner circumferential direction. The grooves on the rotating body side are inclined with respect to the rotation transmission direction, and the round shaft members are rotatable and the engagement length on the rotating body side is on the ratchet member side in the corresponding grooves on the ratchet member and the rotating body. It is characterized in that it communicates so that it is equal to or less than the engagement length.

[0015]

[Operation] In the present invention, when the drive shaft is rotated in a predetermined direction and the rotation of the ratchet member is locked in that state, the movement of each round shaft member in the rotation transmission direction is regulated by each groove of the ratchet member. , the engagement relationship between the rotating body and each inclined groove is released. Therefore, the rotation of the drive shaft is not transmitted to the rotating body via the round shaft member or the like, and the rotation is stopped. At this time, each round shaft member smoothly rolls between the drive shaft and the rotating body, so the friction between the two is reduced. Therefore, the drive shaft etc. will not wear out prematurely.
Additionally, there is no need to refuel at regular intervals, eliminating the need for maintenance.

On the other hand, when the rotation lock state of the ratchet member is released and the rotation lock state is released, the movement restriction in the rotation transmission direction of each of the round shaft members is released, and each of the round shaft members is engaged with each groove of the rotating body. match.

At this time, a reaction force from the groove acts on the portion of each round shaft member that engages with the groove on the rotating body side (rotating body side engaging portion) in a direction opposite to the rotation transmission direction.

This reaction force attempts to rotate the round shaft material around the part of the round shaft material that engages with the groove on the ratchet member side (ratchet member side engagement part), but the rotation body side engagement part Since the length of the part (engaging length on the rotating body side) is less than the length of the engaging part on the ratchet member side (engaging length on the ratchet member side), the arm of the moment of the reaction force does not become longer and the rotational moment It doesn't get bigger.

Therefore, such rotational moment can be sufficiently resisted by the cooperation of the ratchet member side engaging portion of the round shaft member and the groove of the ratchet member. Therefore, each round shaft member is not twisted with respect to the axis of the drive shaft, and uneven contact with each groove of the rotating body and the ratchet member is prevented.

[0020] Thereby, the rotation of the drive shaft is reliably transmitted to the rotating body through the round shaft member, etc., and the rotating shaft is rotated synchronously with the drive shaft. As a result, rotation can be reliably transmitted and cut off while improving durability and ease of handling.

[0021]

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

The clutch mechanism according to this embodiment has a drive unit 1
5, etc., and as shown in FIGS. 1 to 9, it includes a ratchet member 21, a ratchet control means 25, a rotating body (feed hub 31), and a round shaft member (pin 41). It is configured.

Components that are the same as those shown in FIGS. 10 to 12 are designated by the same reference numerals, and their explanations will be omitted or simplified.

Here, a plurality of grooves 23 are formed in the hollow cylindrical portion 22 of the ratchet member 21 along its inner circumferential direction. In this embodiment, the hollow cylindrical portion 22 of the ratchet member 21 has six grooves 23 each extending in the axial direction of the ratchet member 21 (direction perpendicular to the plane of the paper in FIG. is formed along.

Further, the ratchet control means 25 is formed so as to be able to selectively place the ratchet member 21 into a rotationally locked state or a rotationally free state. In this embodiment, the ratchet control means 25 includes a lever 26 that can engage with each tooth of the ratchet member 21, a spring 28 for engaging this lever 26 with the ratchet member 21, as shown in FIG. It includes an electromagnet 27 for separating the lever 26 from the ratchet member 21 against the elastic force of a spring 28. Here, when the electromagnet 27 is energized, the lever 26 rotates clockwise and is positioned at the position shown by the two-dot chain line in the figure, and the rotation lock state of the ratchet member 21 is released and becomes a free state. Also, when the electromagnet 27 is demagnetized, the lever 2
6 is returned to the position shown by the solid line in the figure by the elastic force of the spring 28, and the rotation of the ratchet member 21 is locked.

On the other hand, the rotating body (feed hub 31 in this embodiment) is connected to the feed roller 11, and the hollow cylindrical portion 32 has the same number of ratchet members 21 (ie, six) along the inner circumferential direction. A groove 33 is formed. As shown in FIGS. 5 and 6, each groove 33 is provided so as to be inclined by a predetermined angle θ1 in the rotation transmission direction (arrow R direction).

Specifically, each groove 33 of the rotating body (31) has a bottom surface 33a inclined by a predetermined angle (inclination angle) θ1 with respect to the rotation transmission direction (arrow R direction), and a side wall in the rotation transmission direction. The surface portion 33b is inclined by a predetermined angle θ2 with respect to the radial direction (arrow D direction) of the rotating body (31).

In this embodiment, the bottom portion 33 of the groove 33
The inclination angle θ1 of a is such that the groove 33 and the round shaft material (41) inserted into the groove 33 are engaged with each other with sufficient engagement force to transmit power, and the engagement relationship (engagement relationship) is easily released. It has been selected as possible. More specifically,
When the inclination angle θ1 of the groove 33 of the rotating body (31) becomes larger than 14°, the meshing force between the groove 33 and the round shaft member (41) becomes weak, and conversely, when it becomes smaller than 14°, the meshing force decreases. The angle is set at 14°±2° based on experimental data showing that although the meshing relationship (engaging relationship) becomes stronger, it becomes difficult to release.

Further, the rotation transmission direction side wall surface portion 33b of the groove 33 of the rotary body (hub 31) is arranged as far away as possible from the round shaft member (41) inserted into the groove 33.
1) is inclined by a predetermined angle θ2 with respect to the radial direction. Note that each groove 33 of the rotating body (feed hub 31) is shown in FIG.
As shown in FIG. 3, by appropriately selecting the inclination angle θ2 of the side wall surface portion 33b in the rotation transmission direction, the wall surface portion 33b may be configured to be flush with the bottom surface portion 33a. This configuration completely prevents the round shaft member (41) and the rotation transmission direction side wall surface portions 33b of each groove 33 of the rotating body (31) from colliding with each other during rotation transmission, thereby further improving power transmission and interruption. You can definitely do it.

Further, in each of the corresponding grooves (23, 33) of the feed hub 31 and the ratchet member 21, a round shaft member (pin 41 in this embodiment) is rotatable and has an engagement length L on the rotating body side.
1 is communicated so that the engagement length L2 on the ratchet member side or less.

Here, the engagement length L1 of the round shaft member (41) on the rotating body side means that the round shaft member (41) is connected to the rotating body (feed hub 31).
) side groove 33 (rotating body side engaging portion 41a
) means the length. Furthermore, the ratchet member side engagement length L2 of the round shaft material (41) is the length of the portion of the round shaft material (41) that engages with the groove 23 on the ratchet member 21 side (ratchet member side engagement portion 41b). means.

In this embodiment, the axial length of the groove 33 on the rotating body (feed hub 31) side is set to correspond to the engaging length L1 of the round shaft member (41) on the rotating body side, and the ratchet member 21
By using the collar 45, the length of the side groove 23 in the axial direction corresponds to the ratchet member side engagement length L2 of the round shaft material (41) which is longer than the rotating body side engagement length l1 by a predetermined length. A round shaft member (41) is communicated with the grooves 23, 23 such that the engagement length L1 on the rotating body side is equal to or less than the engagement length L2 on the ratchet member side. More specifically, the rotor-side engagement length L1 of the round shaft member (41) is 5 (mm), and the ratchet member-side engagement length L2 is 18 (mm).

In this embodiment, each round shaft member (41) is attached to each of the rotary bodies (31) in order to achieve more reliable power transmission between the drive shaft 16 and the rotary body (31). Spring member 5 biasing in the direction of digging into the groove 33 (direction of arrow R)
5 is provided.

Specifically, the spring member 55 is disposed between the ratchet member 21 and the feed hub 31, as shown in FIG.
The other end 57 is fixed to a plurality of locking holes 3 provided in the feed hub 31.
It is removably inserted into one of the four.

By appropriately selecting the locking hole 34 of the feed hub 31 into which the other end 57 of the spring member 55 is inserted, the biasing force applied to each pin 41 can be adjusted. For example, when the other end 57 of the spring member 55 is inserted into the locking hole 34b instead of the locking hole 34a, the biasing force of the spring member 55 against each pin 41 is increased, and each pin 41 is attached to the feed hub 31. It is possible to more reliably engage each groove 33 of.

Next, the operation will be explained.

To feed paper using the feed device of the printer described above, first, the drive motor is driven to rotate the drive shaft 16 in the direction of arrow R via the gear 17 and the like. At this time, since each pin 41 is restricted from moving in the rotation transmission direction (R direction) by each groove 23 of the ratchet member 21, it does not engage with each groove 33 of the feed hub 31 (
engagement) not engaged. Therefore, the rotation of the drive shaft 16 is not transmitted to the feed hub 31 (therefore, the feed roller 11) via the pin 41 etc., and the rotational stopped state is maintained.

At this time, since each pin 41 smoothly rolls between the drive shaft 16 and the feed hub 31, the friction between them is reduced. Therefore, the drive shaft 16 and the like will not wear out prematurely. Furthermore, there is no need to refuel at regular intervals.

Next, the electromagnet 2 of the ratchet control means 25
When the rotation lock state of the ratchet member 21 is released into a free state by energizing 7, the movement restriction of each pin 41 in the rotation transmission direction (R direction) is released, and each pin 41 is connected to a rotating body (feed hub). 31) each groove 33
mesh (engage) with

At this time, a reaction force from the groove 33 of the rotor (31) acts on the rotor side engaging portion 41a of the round shaft member (41) in a direction opposite to the rotation transmission direction (R direction).

This reaction force tries to rotate the round shaft member (41) around the ratchet member side engagement portion 41b, but the rotor side engagement length L1 is longer than the ratchet member side engagement length L.
2 or less, the arm of the moment of the reaction force does not become long and the rotational moment does not increase.

Therefore, in response to such rotational moment, the ratchet member side engaging portion 41 of the round shaft member (41)
b and the groove 23 of the ratchet member 21 cooperate with each other to provide sufficient resistance. Therefore, each round shaft material (41
) is not twisted with respect to the axis of the drive shaft 16, and uneven contact with each groove 33 of the rotating body (31) is prevented.

Further, the inclination angle θ1 of the bottom surface portion 33a of each groove 33 is such that each groove 33 and each round shaft member (41) mesh (engage) with sufficient meshing force to transmit power. In addition, each pin 41 is selected so that the meshing relationship (engagement relationship) can be easily released (θ1 = 14°), so each pin 41 is inserted into each groove 3.
3 and is reliably meshed (engaged).

Furthermore, each pin 41 is biased by the spring member 55 in the direction of biting into each groove 33 of the feed hub 31, so that it engages with each groove 33 more reliably.

Furthermore, each groove 33 of the feed hub 31
The rotation transmission direction side wall portion 33b is formed in a direction as far away as possible from each round shaft member (41) that is inserted into each groove 33, so that the wall portion 33b and the round shaft member (41) are
) will not conflict.

[0046] Thereby, the feed hub 31 (feed roller 11) is reliably rotated in synchronization with the drive shaft 16.

On the other hand, when printing, the rotation of the ratchet member 21 is locked by demagnetizing the electromagnet 27. Then, each pin 41 and each groove 33 of the feed hub 31
The engagement with is released. Therefore, the feed hub 31 (
Therefore, the rotation of the drive shaft 16 is not transmitted to the feed roller 11) via the pin 41 etc., and the rotation is stopped.

According to this embodiment, a plurality of grooves 23 are formed along the inner circumferential direction in the hollow cylindrical portion 22 of the ratchet member 21, and the rotating body (feed hub 31)
The same number of grooves 33 are formed in the hollow cylindrical portion 32 along the inner circumferential direction, and the grooves 33 of the rotating body (31) are inclined with respect to the rotation transmission direction (arrow R direction), so that the ratchet member 21 and the rotating body (31) and grooves (23, 33) corresponding to the round shaft members (
Since the pin 41) is configured to be rotatable and communicated so that the engagement length L1 on the rotating body side is equal to or less than the engagement length L2 on the ratchet member side, rotation between the drive shaft 16 and the rotating body (31) is prevented. Transmission is performed via a round shaft member (41) or the like.

Here, when cutting off the rotation, each round shaft member (41
) smoothly rolls between the drive shaft 16 and the rotating body (31), so the friction between them is reduced. Therefore, the drive shaft 16 and the like do not wear out prematurely, and there is no need for oiling at regular intervals, eliminating the need for maintenance. Furthermore, no noise is generated.

[0050] Also, during rotation transmission, each round shaft member (41)
is prevented from coming into partial contact with each groove 33 of the rotating body (31), and is reliably engaged with each groove 33.

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

Furthermore, each round shaft member (4
1) is configured to be biased in the direction of biting into each groove 33 of the rotating body 31, so that power can be transmitted and cut off more reliably.

Furthermore, the biasing force of the spring member 55 against the round shaft member (41) can be changed by cooperation between the plurality of engagement holes 34 provided in the rotating body (31) and the spring member 55. Therefore, it is possible to reliably transmit and cut off power in response to changes in usage conditions, etc.

Although the present invention was applied to a feed device of a printer in the above embodiment, it may also be applied to other industrial equipment.

[0055] Furthermore, the ratchet member 21 and the rotating body (31
) and the length of each groove 23, 33 in the axial direction,
, 33 is selected so that the round shaft member (41) is connected so that the rotor engagement length L1 is equal to or less than the ratchet member side engagement length L2. The form of the material (41) may be selected.

[0056]

According to the present invention, a plurality of grooves are formed along the inner circumferential direction in the hollow cylindrical portion of the ratchet member, and the same number of grooves are formed along the inner circumferential direction in the hollow cylindrical portion of the rotating body. , the groove of the rotating body is inclined with respect to the rotation transmission direction,
The round shaft members are connected to the corresponding grooves of the ratchet member and the rotating body so that they can rotate and the engagement length on the rotating body side is less than or equal to the engagement length on the ratchet member side. Partial contact with each groove of the rotating body is prevented, and power can be reliably transmitted and cut off while improving durability and ease of handling.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention.

FIG. 2 is an exploded perspective view showing essential parts of one embodiment.

FIG. 3 is a half-sectional view showing essential parts of one embodiment.

FIG. 4 is a diagram for explaining paper feeding.

FIG. 5 is a diagram for explaining the mutual positional relationship between the groove of the ratchet member, the pin, and the groove of the feed hub.

FIG. 6 is a diagram for explaining the positional relationship between the pin and the groove of the feed hub in a rotation cutoff state.

FIG. 7 is a diagram for explaining the positional relationship between the pin and the groove of the feed hub in a rotation transmission state.

FIG. 8 is a diagram for explaining a modification of the groove of the feed hub.

FIG. 9 is a diagram showing how the ratchet member is brought into a rotationally locked state or a rotationally free state using a ratchet control means.

FIG. 10 is an overall configuration diagram showing a conventional spring clutch mechanism.

FIG. 11 is an exploded perspective view for explaining details of a conventional spring clutch mechanism.

FIG. 12 is a diagram showing a printer to which a conventional spring clutch mechanism is applied.

[Explanation of symbols]

16 Drive shaft 21 Ratchet member 22 Hollow cylindrical part of ratchet member 23 Ratchet member groove 31 Feed hub (rotating body) 32 Hollow cylindrical part of feed hub 33 Feed hub groove 41 Pin (round shaft material) L1　Rotating body side engagement length of round shaft material

Claims (1)

[Claims] 1. A clutch mechanism that transmits rotation of a drive shaft to a rotating body by setting a ratchet member in a rotation-free state and separating the drive shaft and the rotating body by setting the ratchet member in a rotation-locked state. A plurality of grooves are formed along the inner circumferential direction in the hollow cylindrical portion of the ratchet member, and the same number of grooves are formed along the inner circumferential direction in the hollow cylindrical portion of the rotating body, and The grooves are inclined with respect to the rotation transmission direction, and a round shaft member is placed in each corresponding groove of the ratchet member and the rotating body so that the round shaft member can be rotated and the engagement length on the rotating body side is equal to or less than the engagement length on the ratchet member side. A clutch mechanism characterized by being in communication.