JPS6042079A - Clutch mechanism - Google Patents

Abstract

PURPOSE:To provide a clutch mechanism capable of being disengaged by reversely rotating the first clutch disk by a predetermined rotating angle, wherein the rotation of the first clutch disk provided on the driving side is transmitted to the third clutch disk provided on a driven shaft side through a latch pawl of the second clutch disk. CONSTITUTION:Clutch disks 2, 3 are loosely fitted to a driven shaft 5, while a clutch disk 4 is fixed to the driven shaft 5. A projection 8 of the clutch disk 2 is engaged with a projected piece 10 of the clutch disk 3 only when being rotated in a forward direction (the direction of an arrow), a feeding pawl 9 can be engaged with a receiving pawl 16 of the clutch disk 3, and a latch pawl 17 is integrally fitted to the receiving pawl 16 through a shaft 18. A transmitting gear 7 is rotated in the direction opposite to the direction of the arrow, the pawl 9 pushes the pawl 16 in the direction for engaging the pawl 17, the pawl 17 is engaged with a ratchet wheel 21 for the clutch disk 4, and the engagement is maintained by a locking lever 19. When the clutch disk 2 is further rotated reversely and the pawl 9 kicks the lever 19, the pawl 16 is returned by a traction force of a spring 20, and the clutch mechanism is made to be free.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a unidirectional clutch mechanism used as a one-rotation transfer mechanism.

] In order to apply unidirectional rotation to the θ1-disconnected drive shaft, a unidirectional clutch is usually used.

However, in this one-way clutch, in order to rotate the driven shaft intermittently forward only in one direction,
It is sufficient to use a commonly used ratchet mechanism, but when the clutch mechanism is reversely rotated and then rotated forward again, it is a problem if the driven shaft is rotated from the reverse rotation position to the forward rotation direction again. There are cases.

That is, this means that, for example, an office machine with a platen (
When automatically feeding paper into a printer (such as a printer), the print paper set on the platen is fed in the paper feed direction by forward rotation of the platen, and the print paper is returned several lines in the reverse direction to locate the beginning of paper feed. If the driven shaft of the paper feeder rotates in the forward rotation direction again when the platen is rotated forward again from its reversed position and returned to its original rotational position before the reverse rotation when aligning the positions to the normal position. , there arises an inconvenience in that the printing paper is unnecessarily fed to the platen.

Therefore, in this case, feeding extra paper causes the printing paper fed to the platen to bend and bend in the paper feeding path, resulting in negative effects.

On the other hand, in the above description, there is, for example, the one disclosed in Japanese Patent Publication No. 5B-6633, which performs the paper feeding operation as described above. However, the configuration described in this publication has a structure in which the clutch is engaged by the reverse rotation of the platen, and moreover, the clutch is connected within one maximum rotation of the force-driven transmission wheel. When the drive wheel rotates in the clutch engagement direction by a certain rotational angle, the rotation of the transmission wheel is always transmitted to the separation roll shaft because the entraining disc and the separation roll shaft are always connected in that rotation direction.

Therefore, with such a latch mechanism, when the transmission wheel rotates in the clutch engagement direction, reverse rotation is not possible when power transmission by the clutch is not required.

■--This invention was made in view of the above, and its purpose is to provide a transmission mechanism that rotates a driven shaft intermittently in only one direction, in which the rotation of the drive side that rotates the driven shaft is The clutch has a mechanism that releases the rotation of the drive side from being transmitted to the driven shaft side even if the clutch rotates in the direction of engagement.
It is about providing.

Configuration Next, the present invention will be explained based on an embodiment shown in the drawings.

In Figures 1 and 2, the clutch mechanism (1) is.

It has three clutch plates, the first clutch plate (2)
・The second clutch plate (3) is freely engaged with the driven shaft (5), and the third clutch plate (4) is attached to the fixing screw (
6) to the driven shaft (5).

The first clutch plate (2) is integrally provided with a transmission gear (7), and the first clutch plate further includes a protrusion that can engage with the opposing second clutch plate (3). 8)
And a feed claw (9) is provided. This protrusion (8) is designed to be removed at the periphery of the first clutch plate (2),
The protruding piece ([0) of the second clutch plate (3) and the forward rotation direction (
It is designed so that it can be engaged only when rotating in the direction of the arrow). The projecting piece (lO) has a support shaft (11) as a fulcrum, is received by a stopper (12), is made into a unit by a base (13), and has a groove (14) with respect to the second clutch plate (3). ) so that the fixing position can be adjusted. Therefore, when the first clutch plate (2) rotates in the forward rotation direction shown in the figure, the engagement between the protrusion (8) and the protrusion piece (10) causes the second clutch plate to rotate.
The clutch plate (3) will rotate synchronously in the same direction as the first degree clutch plate (2). Note that the purpose of this synchronous rotation is not to rotate the second clutch plate (3), but to obtain engagement between the protrusion (8) and the protrusion (10) in the forward rotation direction. Therefore, the first step to establish the relationship is
One rotation of the maximum value is sufficient for the clutch plate (2).

As described above, the rotation of the first clutch plate (2) is controlled by a program that rotates the platen, which will be described later, and the position where the first clutch plate (2) rotates once is the so-called protrusion (8) and the protrusion (8). The position in this state is the so-called origin (star 1 to position). Further, in this case, the first clutch plate (2) and the second clutch plate (3) are in a free state with respect to the driven shaft (5), so the driven shaft (5) is not rotated. Since the second clutch plate (3) is loose with respect to the driven shaft (5), it is necessary to prevent it from rotating freely when selecting the origin.
In reality, the brakes add a little bit of force. The brake (work 5) shown in Fig. 3 is an example of a case where there is a plurality of clutch mechanisms (1), and (3a) shows another clutch mechanism (1) installed in parallel.
This is the clutch plate on the a) side. Of course, this brake (15
) may be added independently to the second clutch plate (3).

In the above, when the first clutch plate (2) rotates in the opposite direction to the above, the protrusion (8) rotates in the opposite direction to the protrusion (1).
0), in this case.

The protrusion (10) separates from the stopper (12), making connection impossible, and no rotation is transmitted to the second clutch plate (3) by the protrusion (8).

On the other hand, the feed pawl (9) is adapted to engage with a receiving pawl (16) provided at a position opposite to the second clutch plate (3), and the receiving pawl (16) is connected to the third clutch plate (16). A latch pawl (17) along the inner surface of the clutch plate (4) is integrally attached via a connecting shaft (18), and this latch pawl (17) is mounted on the second clutch plate (3). The receiver has a lock lever (19) on the claw (16) that can receive and hear the rotational position of the claw.
) is the opposite. The latch pawl (17) is normally held apart from the ratchet wheel (21) under the traction of a spring (20). The ratchet wheel (21) is provided integrally with the third clutch plate (4), and when the transmission gear (7) is rotated in the direction opposite to the arrow at the origin position, the first clutch plate (2) The feed pawl (9) presses the receiving pawl (16) of the second clutch plate (3) in the direction in which the latch pawl (17) engages, and the latch pawl (17) engages and joins the ratchet wheel (21). .

In this state, the engagement of the latch claw (17) is maintained by engagement of the lock lever (19) provided opposite to the catch claw (16). The latch pawl (17) is disengaged from the ratchet wheel (21) when the feed pawl (9) is further rotated in the opposite direction.
by kicking the lock lever (19), the receiving claw (1
6) is returned by the pull of the spring (20). Therefore, in this case, each clutch plate (2) and (3
) and (4) are all in the release position, and the clutch mechanism (1) becomes free. Note that (22) is a space adjustment washer.

In the above, the latch claw (17) is attached to the connecting shaft (18) in the configuration shown in FIGS. 4 and 5. The connecting shaft (18) has a pawl holder (23) at one end, and the other end is fixed to a receiving pawl (16) and pivoted to the second clutch plate (3). A groove (24) in which the latch pawl (17) can be loosely attached is provided on the side surface of the pawl holder (23), and the latch pawl (17) is held within this groove (24) by a pivoting screw 25). ing.

A spring (26) is further inserted into this pivot screw, and the latch pawl (17) is constantly pressed toward the ratchet wheel (21) by the spring pressure. Therefore, the latch pawl (17) located within the groove (24)
can freely rotate within the groove by an angle (θ), and is normally held in the position shown by a spring (26).

In the above configuration, when the catch pawl (16) is compressed by the feed pawl (l) and rotates the latch pawl (17) in the engaging direction, in the unlikely event that the latch pawl (17) is pressed against the ratchet wheel. (
The purpose is to prevent the latch pawl (17) from being damaged and compensate for the engagement of the latch pawl (17) when the latch pawl (17) comes into contact with the peak of the wheel and does not engage with the wheel. Therefore, in such a case, the latch pawl (17) will not engage properly with the spring (2).
6) can retreat through oppression. Therefore, the catch and pawl (16) can also be locked by the lock lever (19) by retracting the latch pawl (17) in the above case. On the other hand, since the latch pawl (17) with respect to the ratchet wheel (21) is biased by the spring (26) in the direction of engagement, the second clutch plate (2) due to the forward rotation of the first clutch plate (2) By rotating in the forward direction in step 3), normal engagement can be obtained between the joint seats. In addition, since the meshing surface of the ratchet wheel (21) is actually composed of teeth with a narrow pitch, it is extremely rare for the above-mentioned condition to occur.

Next, an example of use of this clutch mechanism (1) will be explained.

Figure 6 shows an office machine (
For example, this shows a case in which a paper feeding device for automatically feeding paper (cut paper) is linked to a printer (printer), and a paper feeding roller (28) is attached to the driven shaft (5) of the clutch mechanism (1). be.

In the figure, the platen (27) is rotated by a platen gear (30) that meshes with a drive gear (29), and the platen gear (30) is rotated by intermediate gears (31) and (32).
)・(33) to the transmission gear (7) of the driven shaft (5)
It meshes with the. A rubber paper feed roller (28) is mounted on the driven shaft (5). 35).

In addition, when using two sets of paper feed force rollers I-(35),
As shown by the dashed line in the figure, the clutch mechanism (1) is connected to the rubber roller (2) via the intermediate gear (36) with the same configuration.
A clutch mechanism (1a) having a driven shaft (5a) to which a clutch mechanism (8a) is attached is disposed in parallel with the paper feed force cell I- (35a), facing the same.

On the other hand, the intermediate gear (33) is provided with a paper discharge roller (37) for taking out the paper (34) after printing from the platen (27).
) are in mesh with each other.

In the above, intermediate gears (31), (32), (33)
The number may be nine as long as the rotation directions of the platen (27), paper ejection roller (37), and paper feed roller (28) are in the direction of the arrow shown in the figure. In addition, arrows in the illustrations indicate the forward rotation direction of the paper feed roller (28
) to pull out a sheet of paper (34) from the cassette (35), rotate the platen (27) forward by, for example, ``17 lines'', and the engagement of the clutch mechanism (1) will be as described below. There is no configuration in which the printer returns to the original position at the same time.The 17 lines indicate the number of lines printed on the platen (27).

Next, the relationship between the rotation of the platen (27) and the rotation of the paper feed roller (28) attached to the driven shaft (5) will be explained. Note that the rotation of the platen (27) is performed by a program. Further, the paper feed roller (28) used in this invention positions the origin of the clutch mechanism (1)/(la) for each corresponding cassette (35)/(35a) only at the initial stage of drawing out the paper (34). At the same time, the operation error of the clutch mechanisms (1) and (la) at the time of starting paper feeding is cleared. Therefore, this clearer adjusts the rotation ratio of the platen (27) for one rotation of the first clutch plate (2) in the forward direction to, for example, 17.
Leave it as a line. Therefore, this means that the platen (2
7) rotates in the forward direction of the I77 line, the clutch mechanism (1) is automatically set to the origin. In this state.

Next, when the platen (27) is reversely rotated by 7 lines (in the opposite direction of the arrow), the first clutch plate (2) rotates in the reverse direction, and the tip of the feed pawl (9) is rotated in the opposite direction to the second clutch plate (3). Push the receiving claw (16) counterclockwise in FIG. 1 to stop it. Therefore, in this state, the latch pawl (17) is engaged with the ratchet wheel (21), and this engaged state is locked by the lock lever (19). Next, the platen (27) is rotated seven lines in the forward rotation direction. Then, the first clutch plate (2) rotates again in the normal rotation direction (arrow direction), and the protrusion (2) of the first clutch plate (2) again rotates.
8) and the protrusion (10) of the second clutch plate (3) engage, returning to the original position. In this state, the clutch plates (2), (3), and (4) are connected, and the clutch mechanism (1) rotates in the forward rotation direction shown by the arrow with respect to the driven shaft (5). It becomes connected to. Next, when the platen (27) is rotated in the forward direction in this state, the clutch mechanism (1) is connected and the driven shaft (5) and paper feed roller (28) can be rotated in the forward direction. , the paper (34) is moved by the rotational friction of the paper feed roller (28).
can be pulled out from cassette h (35).

In the above, the paper feed rotation of the paper feed roller (28) is, in this case, the rotation of the platen (27) + 24 lines, and when the paper is pulled out according to that rotation ratio, the leading edge of the paper (34) is slightly pulled into the platen (27). There is a correspondence relationship that reaches until the end. Therefore, in this state, when the rotation of the platen (27) stops, the leading edge of the pulled out paper (34) is pulled into the platen (27) by two to three lines and then stopped.

Next, before winding the paper (34) onto the platen (27), the clutch mechanism (1) is disconnected in order to free the paper feed roller (28) from rotating. In this case, the platen (27) is rotated backwards by nine lines. Then, due to this reverse rotation, the platen (27
) The leading edge of the paper (34) that has been pulled in is pushed back, and the leading edge slips at a tangential position with the platen (27), waiting for the next pull-in.

On the other hand, due to this reverse rotation, the first clutch plate (2) rotates in the opposite direction in proportion to the nine lines of the platen (27), and the feed pawl (9) rotates the receiving pawl ( 16
), kick the lock lever (19) that locks it.

Therefore, the catch pawl (16) returns to its original position under the traction of the spring (20), and the latch pawl (17) comes off from the ratchet wheel (21). Therefore, the clutch mechanism (
1) is disconnected, and the driven shaft (5) becomes free together with the third clutch plate (4). Of course, the other first clutch plate (2) and second clutch plate (3) also become free with respect to the driven shaft (5).

On the other hand, in this embodiment, when the platen (27) is reversely rotated by 7 lines at the home position in order to set the above relationship, the clutch mechanism (1) is configured such that the feed pawl (9) is When the clutch mechanism (1) is set to the connected state by pressing the pawl (16) in the latch pawl engaging direction, and the platen (27) is reversely rotated by 9 lines,
Since the lock lever (19) is unlocked and the connection of the clutch mechanism (1) is reset, the protrusion (10)
) can be adjusted with respect to the position of the receiving claw (16). Further, this adjustment may be made by moving the set position of the protrusion (8).

Thus, when the platen (27) rotates forward according to the program, the leading edge of the paper (34), which has been pulled out to the fixed position on the platen (27) and is waiting to be lined up, is immediately pulled into the platen (27) from the fixed position. I can do it.

The drawing direction (length) can be accurately drawn in by the amount of paper feed that should be set. On the other hand, since the clutch mechanism (1) in this case has been disconnected by the above-mentioned operation, the first clutch plate (2) and the second clutch plate (3) will rotate idly. On the other hand, since the driven shaft (5) and paper feed roller (28) are free, they rotate freely as the paper (34) is drawn into the platen (27).

The paper (34) drawn into the platen (27) will be printed by the program, and the paper (34) will be drawn into the platen (27).
) selects the printing line by rotating in the forward direction.

In addition, when selecting the reverse rotation of the print line, in the case of this embodiment, since the clutch mechanism (1) can be connected at 7 lines of reverse rotation of the platen (27), the reverse rotation of the printing line can be selected for up to 6 lines. is the limit. Of course, a desired back line can be selected in this relationship by selecting the setting timing for clutch engagement.

Similarly, when feeding paper from the cassette (35a5), the clutch mechanism (1a)
In this case, the clutch 4Ik structure (l
In a), the feed pawl (
It is only necessary to set the mechanism part 9) to operate.

In the above, clutch mechanism (1) and (1) after setting the origin
From now on, the operation a) is simply a repetition of the operation of pulling out the paper (34).

1-The clutch mechanism of this invention is constructed using three clutch plates that can be connected and released as described above, and is designed to accurately feed paper by rotating the platen in the forward direction.
When feeding paper, the leading edge of the paper can be stably fed out for an appropriate length until it can be pulled into the platen a little. Then, the leading edge of the paper pulled into the platen is reset to the paper feeding position by a slight reverse rotation of the platen to disengage the clutch mechanism, so the platen rotates in the forward direction as printing occurs. On the other hand, paper can be constantly supplied in the paper feeding direction from the proper position to the star 1.

Therefore, according to the present invention, the rotation of the first clutch plate on the driving side is caused by the rotation of the third clutch plate on the driven shaft side via the latch pawl of the second clutch plate, so that the rotation on the driving side is controlled by the clutch. Even if it rotates continuously in the coupling direction, if you do not want the rotation to be transmitted to the driven shaft side, the clutch mechanism can be easily disengaged by rotating the first clutch plate on the driving side by a predetermined rotation angle in the opposite direction. can.

Thus, in this case, the first clutch plate on the driving side can accurately rotate idly relative to the driven shaft.

The clutch mechanism of the present invention is described in the above usage example for feeding paper into an office machine having a platen, but this clutch mechanism can also be used in applications other than the above usage example, such as forward and reverse rotation. Of course, it can be used for versatile purposes.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a clutch mechanism showing an embodiment of the present invention, Fig. 2 is a side view of the same clutch mechanism, Fig. 3 is an explanatory view of adding the brake lever, and Fig. 4 is an illustration of the latch claw removal. FIG. 5 is a plan view of the same upper portion, and FIG. 6 is an explanatory diagram of the use of the clutch mechanism. (1)...Clutch mechanism, (2)...
・・・・・・First clutch plate, (3)・・・・・・・・・
・Second clutch plate, (4)...Third clutch plate, (5)...Driven shaft, (7)・
......Transmission gear, (9)...(...Feed claw, (17)...Latch claw, (21)
......Ratchet wheel.

Claims (1)

[Claims] In a one-way clutch, a plurality of clutch plates are attached to the driven shaft, and among these clutch plates, a first clutch plate has a transmission gear, and a second clutch plate that can be interlocked by rotation of the first clutch plate in the forward direction. is loosely engaged with the driven shaft, and the second clutch plate is provided with a latch pawl that can engage with a ratchet wheel attached to the third clutch plate,
The third clutch plate is fixed to the driven shaft, and the third clutch plate is fixed to the driven shaft.
A clutch mechanism configured such that a latch pawl attached to a clutch plate can be engaged with a pair of ratchet wheels by a feed pawl attached to the first clutch plate.