JPH0761822B2 - Picking device - Google Patents

Description

The present invention relates to a picking device used in a printing device, a copying device, or the like.

[Prior Art] A printing device, a copying device, or the like is provided with a picking device, and the picking device removes the uppermost recording paper from a paper storage unit such as a paper cassette, and then conveys it to a printing unit by a conveyance roller or the like. It is supposed to do.

In this known picking device, the picking roller is generally adapted to transmit or block the driving force from the driving means by an electromagnetic clutch.

[Problems to be Solved by the Invention] However, in the above-described picking device, since the electromagnetic clutch is required, the manufacturing cost is high, and the picking roller is always in contact with the recording paper in the paper storage unit. However, there is a problem that after the recording paper is taken out from the paper storage unit and the rotation of the picking roller is stopped, the picking roller becomes a resistance to the conveyance of the recording paper.

An object of the present invention is to provide a picking device in which a picking roller comes into contact with a recording paper only when the recording paper is taken out from the paper storage unit.

[Means for Solving the Problems] In order to achieve the above object, the picking device of the present invention is
A first position at which the picking roller separates from the recording sheet and a first position at which the picking roller separates from the recording sheet, the lever supporting the picking roller and displaceably supported, and cam means for engaging with a cam follower provided on the lever; 2, a cam wheel for displacing the lever so as to be displaced to the position 2, a driving means capable of rotating the picking roller in a forward and reverse direction, and a clutch for transmitting the rotation of the driving means to the cam wheel by a predetermined rotation angle. The cam means includes a main cam having a peak for holding the picking roller in the first position and a valley for allowing the picking roller to be displaced in the second position, and a positive cam of the driving means. An auxiliary cam that allows the cam follower to fall from the peak to the valley at the time of turning, but prevents the cam follower from dropping from the peak to the valley at the time of reverse rotation of the drive means. And it has a configuration.

[Operation] According to the above configuration, the cam follower of the lever is engaged with the cam means of the cam wheel, and the picking roller is separated from the recording sheet by the rotation of the cam wheel. The picking roller is rotated and displaced by the forward and reverse rotations of the driving means.
The rotation of the driving means is transmitted to the cam wheel by a predetermined rotation angle by the clutch means. Then, the picking roller is displaced by the action of the auxiliary cam to the second position in which the driving means is brought into contact with the recording paper for a certain period at the initial time of the normal rotation of the driving means, and is moved to the first position where it is separated from the recording paper when the driving means is reversely rotated. Retained.

Therefore, the picking roller can be brought into contact with the recording paper to take out the recording paper while rotating the picking roller only during the initial fixed period during the normal rotation of the driving means, and further, after the recording paper is taken out, the driving means continues the normal rotation. Also, the picking roller is kept apart from the recording paper and maintains that state, so that the picking roller does not become a resistance for conveying the recording paper.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to the drawings.

First, an outline of a printer to which the picking device of the present invention is applied will be described.

In FIG. 3, the printer case is composed of an upper case 1, a lower case 2 having a flat upper surface, and a lid 3 on the front surface, and its appearance is a flat box shape having a flat upper surface.

On the rear side of the lower case 2, a box-shaped paper feeding cassette 4 having an upper surface opened at the bottom is loaded from the right side in FIG. In the space 11 above the paper feed cassette 4, a circuit block including a printed circuit board in which a drive control circuit is incorporated is arranged.

A plurality of stacked recording papers 12 are placed on the paper feed cassette 4 from the opening on the upper surface. A hopper plate 13 is attached to the front side of the bottom of the paper feed cassette 4 (see FIG. 4). The hopper plate 13 has a T-shaped plane shape, and a root portion 13c of the hopper plate 13 has a hole 4a formed in the sheet feeding cassette 4.
It is pivotally supported in a state of being fitted to and is swingable around this root portion. Below the hopper plate 13, an urging means for urging the front portion of the hopper plate 13 upward is provided (not shown), and the hopper plate 13 is pushed up by this urging means and both side portions of the front end of the sheet feeding cassette 4 are provided. The front end corner of the recording paper 12 is pressed against the separation claw 9 of FIG.

A frame 5a is fixed to the bottom of the lower case 2 in front of the paper feed cassette 4, and a platen 7 is attached to the frame 5a. The platen 7 is extended in the left-right direction with the contact surface with the recording paper 12 facing upward.

A paper feed roller 6 and a paper discharge roller 8 are attached to the frame 5a in front of and behind the platen 7, parallel to the platen 7. Each of the paper feed roller 6 and the paper discharge roller 8 is composed of a lower drive roller 6a, 8a and an upper pinch roller 6b, 8b. The drive rollers 6a and 8a are rotationally driven by a forward / reverse rotation motor 16 (shown in FIG. 4) described later via a train wheel (not shown). A paper discharge port 20 is formed in the lower case 2 in front of the paper discharge roller 8, and the paper discharge port 20 is located at the height position of the contact surface between the drive roller 8a and the pinch roller 8b of the paper discharge roller 8. The heights are almost the same.

A print head 10 is arranged above the platen 7 so as to face it. The print head 10 is of a print wire impact type in this embodiment. Print head
A slider 23 is fixedly attached to 10 and the receiving portion 10b
Are integrally formed, and can be moved along the guide shafts 21 and 22 via the slider 23 and the receiving portion 10b with the printing portion facing downward. The print head 10 can be reciprocated by a carriage motor (not shown) via a timing belt (not shown). The guide shaft 22 is fixed to the lid 3, and the receiving portion 10b is opened to the side, so that when the lid 3 is opened, the guide shaft 22 receives the receiving portion 10b.
It comes off from b.

A ribbon cassette 25 is arranged above the print head 10. The ribbon cassette 25 has arms 25a on both sides, and both arms 25a
The ink ribbon exposed from between the platen 7 and the print head
It is located between 10 and. The ribbon cassette 25 is mounted by opening the lid 3. The ribbon cassette 25 is also driven by a carriage motor via a train wheel (not shown).

Next, the picking device will be described.

A forward / reverse rotation motor is provided at the right end of the frame 5b as shown in FIG.
16 is attached. The frame 5b is fixed to the bottom of the lower case 2.

A drive shaft 31 is connected to the forward / reverse rotation motor 16 via a train wheel 33. The drive shaft 31 is rotatably supported below the frame 5b via a bearing 32. This drive shaft 31 has a first
As shown in FIGS. 2 and 2, the lever 34 is pivotally supported,
The lever 34 is biased in the counterclockwise direction in FIG. 2 around the drive shaft 31 by the tension spring 52.

A cam follower 34a is provided at one end of the lever 34, and a roller shaft 35 is rotatably supported at the other end. The roller shaft 35 and the drive shaft 31 are meshed with gears 37 and 38 fixed to them, and are rotationally driven by the driving force of the forward / reverse rotation motor 16. Picking rollers 36 are attached to both ends of the roller shaft 35, respectively. A one-way clutch is provided between the picking roller 36 and the roller shaft 35.
36a is interposed, and when the roller shaft 35 is rotated clockwise in FIG. 2, the driving force of the roller shaft 35 is transmitted to the picking roller 36 and the picking roller 36 is rotated. The driving force of the roller shaft 35 is prevented from being transmitted to the picking roller 36 when rotated counterclockwise in the figure.

On the other hand, a pair of bearings 39 project from the frame 5b on the side opposite to the roller shaft 35 with respect to the drive shaft 31, and a rotary shaft 40 is rotatably supported by the pair of bearings 39. . Axis of rotation
A gear 41 is fixed to 40, and this gear 41 meshes with the gear 37 and is rotationally driven by the driving force of the forward / reverse rotation motor 16.

A cam wheel 42 is rotatably attached to the rotating shaft 40. Sleeves 42a and 42b are formed at the center of the cam wheel 42, and clutch springs 43 and 44 are wound around the rotary shaft 40 with a predetermined frictional force inside the sleeves 42a and 42b.
A long groove (see FIG. 1) is formed in the sleeve portions 42a, 42b in the axial direction, and one end portion 43a, 4 of the clutch spring 43, 44 is formed in this long groove.
4a is locked. The winding directions of the clutch springs 43 and 44 are the same, and the clutch spring 43 is wound when the rotating shaft 40 is rotated counterclockwise in FIG. When the rotary shaft 40 is rotated clockwise in FIG. 2, the clutch spring 44 is wound and tightened to rotate the cam wheel 42 together with the rotary shaft 40. A circumferential groove (not shown) is formed at the tips of the sleeve portions 42a, 42b, and the other end portions 43b, 44b of the clutch springs 43, 44 pass from the inside of the sleeve portions 42a, 42b through the circumferential groove. It is projected to the outside.

A main cam 46 is integrally formed on the right side surface of FIG. 1 in the cam wheel 42, and the cam follower 34 of the lever 34 is attached to the main cam 46.
a can be followed by the urging force of the tension spring 52. As shown in FIG. 2 (FIGS. 5 to 9), the contour of the main cam 46 is formed with a peak portion 46a and a valley portion 46b. When the cam follower 34a rides on the peak portion 46a, the picking roller 36 Are separated from the uppermost recording paper 12. Further, when the cam follower 34a is dropped from the mountain portion 46a to the valley portion 46b, the picking roller 36 is placed at the top of the recording paper 12
It comes into contact with. The boundary between the mountain portion 46a and the valley portion 46b has a steep descent surface 46c on one side and a gentle descent surface 46d on the other side.

Further, in the cam wheel 42, an auxiliary cam 47 is swingably supported on the trough portion 46b side of the main cam 46 via a pin 42c (second).
(See FIGS. 5 to 9 and not shown in FIG. 1). The auxiliary cam 47 has an arc shape, and a pair of arms 47a and 47b are formed on both sides of the swing center. This auxiliary cam 47 is urged counterclockwise in FIG. 2 around the pin 42c by the tension spring 48, and normally this one arm 47a is connected to the upper surface of the mountain portion 46a on the side of the gentle descent surface 46d. The cam followers 34a come into contact with each other, and the cam followers 34a from the peaks 46a to the valleys 46b from the side of the gentle descent surface 46d.
Is prevented from falling. Further, when the arm 47a is in contact with the upper surface of the mountain portion 46a on the side of the gentle descent surface 46d, the arm 47a
b is located above the mountain portion 46a on the side of the steep descent surface 46c, and the cam follower 34a can pass from the mountain portion 46a to the valley portion 46b along the steep descent surface 46c by passing between the arm 47b and the mountain portion 46a. There is. Further, when the auxiliary cam 47 is swung clockwise around the pin 42c in FIG. 2 against the biasing force of the tension spring 48, the arm 47b can come into contact with the upper surface of the mountain portion 46a on the steeply descending surface 46c side. ing.

Further, the stoppers 49, 50 are provided on the frame 5b so as to be able to contact the ends 43b, 44b of the clutch springs 43, 44 by rotation of the cam wheel 42.
Are formed. The end portion 43b of the clutch spring 43 contacts the stopper 49 from above, and the end portion 44b of the clutch spring 44 contacts the stopper 50 from below. In the present embodiment, the end portions 43b, 44b of the clutch springs 43, 44 and the stoppers 49, 50 are in a state in which the end portion of one clutch spring is in contact with one stopper, and the cam wheel 42 is approximately 270.
The positional relationship between the two clutch springs is determined so that the end portion of the other clutch spring comes into contact with the other stopper when rotated once.

Next, the operation will be described.

The cam wheel 42 is in the state shown in FIG. 5 in the initial state or during printing. During printing, the forward / reverse rotation motor 16 rotates in the forward direction (the forward rotation direction is when the picking roller 36 rotates in the recording paper ejection direction) and the rotation shaft 40 rotates clockwise in this state. However, in this state, the end portion 44 of the clutch spring 44 is rotated as shown in FIG.
The b comes into contact with the stopper 50 to loosen the clutch spring 44. As a result, both clutch springs 43 and 44 are loosely wound, and the rotation of the rotary shaft 40 is prevented while the cam wheel 42 is prevented from rotating further. Spin idle. Further, in this state, the cam follower 34a is in contact with the upper surface of the mountain portion 46a of the main cam 46, and the picking roller 36 is separated from the recording paper 12 (second position). This state is maintained until the end of printing and the next picking signal.

When the picking signal arrives, the forward / reverse rotation motor 16 is rotated in the reverse direction. Then, the rotary shaft 40 is rotated counterclockwise, the clutch spring 43 is wound, and the cam wheel 42 rotates together with the rotary shaft 40 (counterclockwise in FIG. 5). Then, the rotation of the cam wheel 42 causes the cam follower 34a to transfer onto the arm 47a of the auxiliary cam 47 from the upper surface of the mountain portion 46a. When the cam follower 34a exceeds the swing center of the auxiliary cam 47, the cam follower 34a swings the auxiliary cam 47 clockwise around the pin 42c against the biasing force of the tension spring 48. By this swinging motion, the arm 47b of the auxiliary cam 47 contacts the upper surface of the mountain portion 46a on the side of the steeply descending surface 46c (FIG. 6), and the cam follower 34a passes over the arm 47b and transfers to the upper surface of the mountain portion 46a. And clutch spring 4
When the end 43b of 3 contacts the stopper 49, the clutch spring
43 is loosened, and as a result, both clutch springs 43 and 44 are in a loosened state, and the rotary shaft 40 idles while the cam wheel 42 is prevented from rotating further (FIG. 7). At this time, since the cam follower 34a does not drop into the trough portion 46b, the picking roller 36 is maintained at the position (first position) apart from the recording paper 12. Therefore, during this period, the picking roller 36 does not rotate, but does not affect the recording paper 12. Incidentally, the reverse rotation of the forward / reverse rotation motor 16 causes the reverse rotation of the paper feed roller 6 as well.
Since 12 does not exist at the position of the paper feed roller 6, there is no problem.

When a certain time has passed since the picking signal arrived, the forward / reverse rotation motor 16 changes to forward rotation. Then, the rotating shaft 40 is rotated in the clockwise direction and the clutch spring 44 is tightened, and the cam wheel is
42 rotates together with the rotating shaft 40 (clockwise in FIG. 7). Then, the rotation of the cam wheel 42 causes the cam follower 34a to move to the mountain portion 4
It moves on the upper surface of 6a, falls between the arm 47b and the crest portion 46a and falls along the steeply descending surface 46c to the trough portion 46b, and the picking roller 36 hits the recording paper 12 as shown in FIG. It is displaced to the contact position (second position). At the same time, the uppermost recording paper 12 is taken out by the rotation of the picking roller 36. This operation is performed until the cam follower 34a comes into contact with the gently descending surface 46d (Fig. 9), and the recording paper 12 is taken over by the paper feed roller 6 during this time.

After the cam follower 34a comes into contact with the slow descent surface 46d, the cam follower 34a goes up the slow descent surface 46d and the arm 47a of the auxiliary cam 47
And the cam follower 34a pushes up the arm 47a, passes between the arm 47a and the upper surface of the mountain portion 46a, and rides on the upper surface of the mountain portion 46a. With the cam follower 34a riding on the upper surface of the mountain portion 46a, the end portion 44b of the clutch spring 44 is stopped by the stopper 50.
Abut. Then, the clutch spring 44 is wound and loosened,
As a result, both clutch springs 43 and 44 are wound together loosely, and the rotation of the rotary shaft 40 is stopped while the cam wheel 42 is prevented from rotating further, whereby the state shown in FIG. 5 is maintained. Printing is performed in this state. The recording paper 12 taken over by the paper feed roller 6 is conveyed between the print head 10 and the platen 7 by the paper feed roller 6 and is transferred to the print head 10.
Then, printing is performed, and after printing, the paper is discharged from the paper discharge port 20 by the paper discharge roller 8. Further, the attachment / detachment of the paper feed cassette 4 is also performed in the state shown in FIG.

As described above, in this embodiment, the picking roller 36 is temporarily brought into contact with the recording paper 12 to take out the recording paper 12, and the picking roller 36 is immediately separated from the recording paper 12 after that. Can be transported smoothly after taking out.
In addition, for example, when the paper feed cassette 4 is removed and the recording paper 12 is manually fed, or when the paper feed roller 6 and the paper ejection roller 8 are reversed and the recording paper 12 is manually fed from the paper ejection port 20. Even when the picking roller 36 does not automatically feed the recording paper 12, the recording paper 12 can be smoothly supplied without being caught by the picking roller 36. In the latter case of manual feeding, the paper exit 20
The recording paper 12 supplied from the paper is temporarily sent to the paper feed cassette 4 side by the paper feed roller 6 and the paper discharge roller 8,
After that, the paper is fed by the paper feed roller 6 between the print head 10 and the platen 7 and printed by the print head 10. After printing, the paper is discharged from the paper discharge port 20 by the paper discharge roller 8.

Moreover, since the picking roller 36 is rotated and displaced by the forward / reverse rotation motor 16 for feeding the paper, it is not necessary to provide a dedicated drive means, and the cost is low.

Although a pair of clutch springs 43 and 44 are used in the above embodiment, one clutch spring 43 is omitted and the locking pin 100 is projected onto the cam wheel 42 as shown in FIGS. 10 and 11. Set up
Fig. 11 Locking pin when cam wheel 42 rotates counterclockwise
The 100 may be brought into contact with the stopper 49 from above. In this case, even if the rotating shaft 40 is rotated counterclockwise in FIG. 11, the frictional force between the rotating shaft 40 and the clutch spring 44 is adjusted so that the cam wheel 42 rotates together with the rotating shaft 40. Largely set. As a result, when the rotary shaft 40 rotates counterclockwise in FIG. 11, the cam wheel 42 rotates together with the rotary shaft 40. Then, when the locking pin 100 comes into contact with the stopper 49, the clutch spring 44 is unwound and the rotating shaft 40 idles. On the other hand, when the rotary shaft 40 rotates clockwise in FIG. 11,
The clutch spring 44 is wound and the cam wheel 42 rotates together with the rotating shaft 40, and this rotation causes the end portion 44 of the clutch spring 44 to rotate.
When b comes into contact with the stopper 50, the clutch spring 44 is unwound and the rotating shaft 40 idles.

Also, as shown in FIGS. 12 and 13, the clutch spring is
The middle part of 44 is the sleeve part 4 of the cam wheel 42 with the adhesive 101.
It is fixed to the inner circumference of 2b, one end 44a of the clutch spring 44 is brought into contact with the stopper 49 from above, and the other end of the clutch spring 44 is abutted.
The 44b may be brought into contact with the stopper 50 from below. A groove 40a for escape of the adhesive 101 is formed on the rotary shaft 40. In this case, when the rotary shaft 40 rotates counterclockwise in FIG. 13, the end portion 42a side is wound around the adhesive portion of the clutch spring 44, and the cam wheel 42 rotates together with the rotary shaft 40. By rotation, the end 44a of the clutch spring 44
When the stopper abuts on the stopper 49, the end 42a side is unwound around the adhesive portion of the clutch spring 44, and as a result, both sides of the adhesive portion of the clutch spring 44 are in an unwinding state and the rotating shaft 40 idles. On the other hand, when the rotary shaft 40 rotates in the clockwise direction in FIG.
The cam wheel 42 is rotated together with the rotating shaft 40 by tightening the side 42b, and when this rotation causes the end portion 44b of the clutch spring 44 to come into contact with the stopper 50, the end portion 42b side is separated by the adhesive portion of the clutch spring 44. Unwound and consequently clutch spring 4
Both sides of the adhesive part of 4 are wound together and become loose.
Spins idle.

Alternatively, as shown in FIGS. 14 and 15, both of the pair of clutch springs 43 and 44 may be omitted and other clutch means may be used.

In the clutch means shown in FIGS. 14 and 15, the rotary shaft is
40 is the lever 10 inside the sleeves 42a, 42b of the cam wheel 42.
One end of each of 2, 103 is fitted so as to be relatively rotatable. The other ends of the levers 102 and 103 are engaged with the sleeve portions 42a and 42b of the cam wheel 42 so as to be rotated integrally with the cam wheel 42. The tip portion of the lever 102 corresponds to the stopper 50 outside the sleeve portion 42a, and is brought into contact with the stopper 50 from below when the cam wheel 42 is rotated clockwise in FIG. On the other hand, the tip of the lever 103 is
Corresponding to the stopper 49 on the outer side of 2b, when the cam wheel 42 is rotated clockwise in FIG. 15, it comes into contact with the stopper 49 from above. Further, the levers 102 and 103 are provided with notches 102a and 103a at their fitting portions with the rotary shaft 40, and rolling elements 104 and 105 are provided inside the notches 102a and 103a. The cutouts 102a and 103a are provided in such a size that the rolling elements 104 and 105 can roll in the circumferential direction of the rotary shaft 40. Further, the cutouts 102a, 103a are gradually narrowed from one side in the circumferential direction of the rotating shaft 40 to the other side, and the minimum width is the rolling elements 104, 105.
Is smaller than the diameter of, and the directions are opposite to each other. The rolling elements 104 and 105 can move in the circumferential direction of the rotary shaft 40 while rotating by the frictional force with the rotary shaft 40 when the rotary shaft 40 rotates, inside the notches 102a and 103a.

In this case, when the rotary shaft 40 rotates clockwise in FIG. 15,
The rolling element 104 moves in the circumferential direction of the rotary shaft 40 in the cutout portion 102a of the lever 102, reaches the narrow portion of the cutout portion 102a and bites between the lever 102 and the rotary shaft 40, and the cam wheel 42 rotates the rotary shaft 40. Rotate with. When the tip projection of the lever 102 comes into contact with the stopper 50 from below, the rolling element 105 reaches the wide portion of the cutout portion 102a of the lever 102, and as a result, the rolling elements 104 and 105 of the cutout portions 102a and 103a of the levers 102 and 103 are formed. Positioned in the wide part, the rotating shaft 40 spins idle.

On the other hand, when the rotary shaft 40 rotates counterclockwise in FIG. 15, the rolling element 105 moves in the circumferential direction of the rotary shaft 40 in the notch 103a of the lever 103 to reach the narrow portion of the notch 103a and reach the lever 103. The cam wheel 42 bites into the rotation shaft 40, and the cam wheel 42 rotates together with the rotation shaft 40. When the tip projection of the lever 103 comes into contact with the stopper 49, the rolling element 105 reaches the wide portion of the notch 103a of the lever 103, and as a result, the rolling elements 104 and 105 are both levers 102 and 1.
The rotary shaft 40 is idled by being positioned in the wide portion of the cutouts 102a, 103a of 03.

Further, although the cam wheel 42 is attached to the rotary shaft 40 and the clutch means is provided between the both, the cam wheel 42 is supported at another portion, and the rotary wheel 40 is provided with the rotary wheel for transmitting the rotational force to the cam wheel 42. A clutch means may be provided between the rotary wheel and the rotary shaft 40.

Further, in the present invention, the mountain portion of the main cam is a portion where the movement locus of the cam follower is far from the rotation center, the valley portion is the portion where the movement locus of the cam follower is close to the rotation center, and the main cam is the configuration of the above embodiment. In addition to the above case, various shapes can be applied.

Further, the picking device of the present invention is not limited to the printer having the above-mentioned configuration, but can be applied to an electrophotographic recording device.

[Advantages of the Invention] As described above, in the picking device according to the present invention,
Since the picking roller can be separated from the paper in the paper accommodating section except when the recording paper is being taken out, the picking roller does not become a resistance during the conveyance of the recording paper, and the recording paper can be smoothly conveyed. It is possible to manually feed paper without providing a special paper feed port.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of a picking device of the present invention, FIG. 2 is a right side view thereof, FIG. 3 is a longitudinal sectional view of a printer to which the picking device of the present invention is applied, and FIG. Third
FIG. 5 to FIG. 9 are sectional views taken along the line BB of FIG. 5, which are explanatory views of the operation of the picking device of the present invention, and FIG.
FIG. 11 is a right side view thereof, FIG. 12 is a plan view of the third embodiment,
FIG. 13 is a right side view thereof, FIG. 14 is a plan view of the fourth embodiment,
FIG. 15 is a right side view thereof. 4 ... Paper feed cassette (paper storage unit), 12 ... Recording paper, 16 ... Forward / reverse rotation motor (driving means), 34 ... Lever, 34a ... Cam follower, 36 ... Picking roller, 40 ... Rotation Shafts, 42 ... Cam wheels, 43,44 ... Clutch springs, 46 ... Main cams, 46a ... Mountains, 46b ... Valleys, 47 ... Auxiliary cams, 47a, 47b ... Arms, 49,50 ...... Stopper (stopper member).

Claims (6)

[Claims] 1. A picking device having a picking roller arranged to face a paper accommodating portion, and rotationally driving the picking roller to take out the uppermost recording paper from the paper accommodating portion. A lever that supports and displaceably supports the cam, and a cam means that engages with a cam follower provided on the lever, and the picking roller is separated from the recording paper at a first position and the recording paper. A cam wheel that displaces the lever so as to displace to the abutting second position, drive means that can rotate forward and reverse to cause rotation and displacement of the picking roller, and rotation of the drive means by a predetermined rotation angle. Clutch means for transmitting to the cam wheel, wherein the cam means includes a mountain portion that holds the picking roller in the first position and the picking roller. Is allowed to move to the second position, and a main cam having a trough portion is allowed to move to the second position, and the cam follower is allowed to drop from the crest portion to the trough portion at the time of normal rotation of the driving means. And an auxiliary cam that prevents the cam follower from falling from the crest portion to the trough portion at the time of reverse rotation of the picking device. 2. The ridge portion of the main cam according to claim 1, wherein the leading end portion at the time of forward rotation is formed as a gentle descent surface and the opposite end portion is formed as a sudden descent surface. The cam is swingably provided on the trough side of the main cam and has a pair of arms extending substantially in an arc shape on both sides of the swing center. One arm is in contact with the end of the main cam on the side of the gentle descent surface, and the other arm is biased so as to be spaced from the end of the main cam on the side of the steep descent surface. Characteristic picking device. 3. A clutch shaft according to claim 1 or 2, wherein said clutch means is a rotary shaft on which said cam wheel is engaged and is rotated in association with said drive means, and said cam wheel wound around said rotary shaft. A pair of clutch springs that rotate in accordance with the rotating shaft, and contact the end portions of one clutch spring when the cam wheel rotates in one direction following the rotating shaft, and the rotating shaft. And a stopper member that makes the rotation shaft idle by contacting the end portion of the other clutch spring when the cam wheel follows the rotation shaft and is rotated in the other direction. Picking device. 4. The clutch means according to claim 1, wherein the clutch means includes a rotary shaft on which the cam wheel is engaged and is rotated in association with the driving means, and a locking pin provided on the cam wheel. A clutch spring wound around the rotating shaft to rotate the cam wheel following the rotating shaft, and an end portion of the clutch spring when the cam wheel rotates in one direction following the rotating shaft. And a stopper member that idles the rotary shaft by making contact with the locking pin and idles the rotary shaft when the cam wheel follows the rotary shaft and is rotated in the other direction. Picking device characterized by. 5. The clutch means according to claim 1 or 2, wherein the clutch means includes a rotary shaft on which the cam wheel is loosely engaged and which is rotated in association with the drive means, and an intermediate portion wound around the rotary shaft. A clutch spring fixed to the inner circumference of the cam wheel to rotate the cam wheel following the rotating shaft; and a clutch spring when the cam wheel rotates in one direction following the rotating shaft. Abutting one end of the rotary shaft to idle, and when the cam wheel follows the rotary shaft and is rotated in the other direction, abuts the other end of the clutch spring to idle the rotary shaft. And a stopper member. 6. The cam mechanism according to claim 1 or 2, wherein the clutch means is a rotary shaft with which the cam wheel engages and is rotated in conjunction with the drive means, and the cam engages with the rotary shaft and the cam. A pair of clutch levers engaged with the vehicle, and provided between the clutch lever and the rotary shaft so as to be rollable in the circumferential direction of the rotary shaft to rotate the cam wheel following the rotary shaft. When the rolling element and the cam wheel follow the rotary shaft and are rotated in one direction, they abut the one clutch lever to idle the rotary shaft, and the cam wheel follows the rotary shaft. A picking device, comprising: a stopper member that comes into contact with the other clutch lever and rotates the rotation shaft idly when rotated in the other direction.