CN102211469A - Transportation device - Google Patents

Abstract

The invention provides a transportation device, capable of preventing the double feeding of the transported media. The transportation device includes a pick-up unit having a first arm that is rotatable about a first rotation section, a second arm that is rotatable about a second rotation section with respect to the first arm and is provided with a feeding roller fixed thereon, and a torsion coil spring that acts on the second rotation section so as to bias the feeding roller toward the paper sheets. The first arm has a first fixation section that fixes in place one end of the torsion coil spring, while the second arm has a second fixation section that fixes in place the other end of the torsion coil spring. A plurality of spring latches is disposed on at least one of the first fixation section and second fixation section so as to adjust a spring force of the torsion coil spring.

Description

Conveyor

technical field

The present invention relates, for example, to a conveying device for an inkjet printer or the like.

Background technique

Conventionally, a printer is provided with a conveying device for separating and feeding paper (a medium to be conveyed) one by one from a bundle of paper placed on a loading tray of the printer. In such a transport device, in order for the feed roller to reliably feed the paper, the feed roller is pressed against the paper to maintain a state where the feed roller is in pressure contact with the paper (for example, refer to Patent Document 1).

The configuration of a conventional conveying device will be described with reference to FIG. 10 .

The transport device 100 is provided with a loading tray 110 on which the paper Q is placed, and a feed roller 120 for transporting the paper Q placed on the loading tray 110 to the recording unit of the printer. The feed roller 120 is mounted on a drive shaft 140 as a drive shaft via an arm 130 . The rotation of the drive shaft 140 is transmitted to the feed roller 120 via a gear train not shown, whereby the feed roller 120 rotates. Further, the conveyance device 100 is equipped with a torsion coil spring 150 that urges the arm 130 toward the paper Q, that is, counterclockwise in the drawing. As a result, the feed roller 120 is brought into pressure contact with the paper Q. As shown in FIG. In addition, by rotating the feed roller 120 in a clockwise direction as indicated by a hollow arrow in the figure, the paper Q is sent out in a paper conveying direction indicated by an arrow of a dashed-dotted line.

In such a transport device 100 , the arm 130 and the feed roller 120 rotate toward the loading tray 110 around the drive shaft 140 as the number of sheets Q decreases by the biasing force of the torsion coil spring 150 . Thereby, the pressure contact of the feed roller 120 to the uppermost paper Q of the paper bundle is maintained according to the number of paper Q sheets.

Patent Document 1: JP-A-2003-285936

However, the biasing force of the torsion coil spring 150 is uneven with respect to the preset biasing force due to the unevenness of the product of the spring 150 itself or the installation error of the conveying device 100 . As a result, the pressure contact force of the feed roller 120 to the paper Q becomes uneven. As a result, when the pressing force of the feed roller 120 against the paper Q is too large, multifeed (multiple feeding) of the paper Q occurs.

Contents of the invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide a conveying device capable of suppressing double feeding of conveyed media.

In order to achieve the above object, the present invention provides a conveying device, which is characterized in that it comprises: a conveying device main body, which uses feed rollers to convey the conveyed medium; a first arm, which is installed on the conveying device main body, and can be The first rotating part rotates relative to the main body of the conveying device; the second arm is mounted on the first arm and can rotate relative to the first arm centering on the second rotating part, and The feed roller is fixed on a side opposite to the first rotation part with respect to the second rotation part; a torsion coil spring is used to urge the feed roller toward the conveyed medium. The method acts on the second rotating part, and a first fixing part is provided on the first arm, and the first fixing part fixes one end of the torsion coil spring, and a second fixing part is provided on the second arm. Two fixing parts, the second fixing part fixes the other end of the torsion coil spring, and at least one of the first fixing part and the second fixing part is provided with a plurality of spring hooking parts, the The spring hooking part is used for adjusting the spring force of the torsion coil spring.

According to this structure, since the spring force of the torsion coil spring can be adjusted by the spring hook portion, it is possible to suppress the unevenness of the spring force of the torsion coil spring itself or the unevenness of the spring force of the torsion coil spring due to installation errors and the like. all. This prevents the pressure contact force of the feed roller from becoming excessively large against the conveyed medium, so that double feeding of the conveyed medium can be suppressed.

In the conveying device of the present invention, the torsion coil spring is elastically deformed according to the rotation of the second arm relative to the first arm, whereby the torsion coil spring directs the feed roller toward the Forced by the conveyed medium.

In the case where the second arm rotates relative to the first arm, the torsion coil spring urges the feed roller toward the conveyed medium by elastically deforming the torsion coil spring, so that the second arm does not rotate relative to the first arm without rotating the second arm relative to the first arm. Compared with the case where the first arm and the second arm are integrally rotated about the first rotating portion, the force applied to the conveyed medium by the feed roller becomes larger.

In this structure, when the medium to be conveyed is inserted between the feed roller and the mounting surface, the first arm and the second arm are integrally centered on the first rotating portion by the force of the medium to be conveyed pressing the feed roller. turn. This suppresses an increase in the force applied by the feed roller to the conveyed medium, and therefore suppresses an increase in the force with which the feed roller presses against the conveyed medium. Thereby, the to-be-conveyed medium can be easily mounted on a conveyance apparatus.

In the conveying device according to the present invention, a mounting surface on which the medium to be conveyed is placed is provided at a position facing the feeding roller of the conveying device, A cover is provided at a position facing the conveying medium, and the cover covers the first rotating part from the outside in the radial direction of rotation of the first rotating part, and the gap between the mounting surface and the cover is used to restrict the The number of loaded sheets of the conveyed medium.

When the second rotating part is provided with a mechanism to limit the number of loaded sheets of the conveyed medium, the second rotating part will rotate with the first arm and the second arm in the condition that the conveyed medium is conveyed by the feed roller. Since the rotating part rotates around the center, the position of the second rotating part relative to the mounting surface changes. As a result, the position at which the number of loaded sheets of the medium to be conveyed is restricted changes. Therefore, it cannot be clearly defined to what extent the conveyed medium can actually be placed.

In this regard, in the present invention, since the cover covers the first rotating part from the outside in the rotational radial direction of the first rotating part, the position of the cover relative to the mounting surface does not change when the first rotating part rotates. Therefore, the positions of the mounting surface and the cover do not change in the case where the medium is conveyed by the feed rollers. Thereby, the number of loaded sheets of the medium to be conveyed can be clearly limited.

In the conveying device according to the present invention, the cover is provided within a range where the first arm rotates in accordance with the operation of the feed roller that conveys the conveyed medium.

According to this configuration, since the cover is provided within the range in which the first arm turns, it is possible to prevent the conveyed medium from coming out of the gap between the mounting surface and the cover during the turn of the first arm.

In the conveying device of the present invention, the torsion coil spring is provided with a linear arm portion at least one of the winding start portion and the winding end portion of the wound coil portion, and the plurality of spring hook portions are formed by The arm is mounted on the rib, and the spring force of the torsion coil spring is adjusted by changing the rib on which the arm is mounted.

According to this configuration, when the operator adjusts the spring force of the torsion coil spring, it can be adjusted only by detaching the arm from the rib and attaching it to another rib. Accordingly, the operator can easily perform the operation of adjusting the spring force of the torsion coil spring.

Description of drawings

FIG. 1 is a schematic perspective view of a printer according to an embodiment.

Fig. 2 is a schematic perspective view of the conveying device according to the embodiment.

Fig. 3 is an exploded perspective view of a pickup unit according to the embodiment.

Fig. 4 is a schematic diagram showing a gear train of a pickup unit.

Fig. 5 is a perspective view showing the front structure of the pick-up unit.

FIG. 6( a ) is a side view showing the transport device in a standby state, and FIG. 6( b ) is a schematic view showing the transport device in FIG. 6( a ).

Fig. 7(a) is a side view showing the conveying device just before conveying, and Fig. 7(b) is a schematic diagram showing the conveying device in Fig. 7(a).

FIG. 8( a ) is a side view showing the conveying device in a paper conveying state, and FIG. 8( b ) is a schematic view showing the conveying device in FIG. 8( a ).

FIG. 9( a ) is a side view showing the conveying device immediately before conveying when thick paper is used, and FIG. 9( b ) is a schematic diagram showing the conveying device in FIG. 9( a ).

Fig. 10 is a schematic diagram showing a conventional conveying device.

Symbol Description

11...Printer, 12...Conveyor, 21a...Loading surface, 23...Support shaft (conveyor main body), 26...Separation pad (separation mechanism), 31...No. One arm, 32...second arm, 33...feed roller, 35...torsion coil spring, 35b...first engaging part (arm part), 42...upper cover part ( cover), 42c...groove (first fixed part), 61...first rotating part, 62...second rotating part, 70...spring fixing part (second fixing part), 71. ..First adjustment part (spring hook part), 72...Second adjustment part (spring hook part), 73...Third adjustment part (spring hook part), 74...Fourth adjustment Section (spring hooking section), 75 ... fifth adjusting section (spring hooking section), 76 ... rib, P, P1, P2, P3 ... paper (transmitted medium).

Detailed ways

Hereinafter, specific embodiments of a conveying device used as an inkjet printer (hereinafter referred to as "printer") using the conveying device of the present invention will be described with reference to FIGS. 1 to 9 . In addition, in the following description, unless otherwise specified, the use of "front-back direction", "up-down direction" and "left-right direction" refers to the "front-back direction" and "up-down direction" indicated by the arrows in FIG. and "left and right direction". In addition, in this embodiment, the vertical direction is defined as the same direction as the vertical direction.

As shown in FIG. 1 , the printer 11 is a recording device that records characters, images, and the like on paper as a conveyed medium supplied from the rear side. The printer 11 is provided with: a conveying device 12 which is an automatic sheet feeder (ASF: Auto Sheet Feeder) for conveying paper, a recording device 13 which records images, etc. The paper output port 14 for paper such as images.

As shown in FIG. 2 , the transport device 12 is provided with a loading tray 21 on which paper is placed. The loading tray 21 has an inclined loading surface 21a on which paper is placed, and a support surface 21b that is a plane along the front-rear direction and the left-right direction. A guide wall 22 is provided at the right end of the loading tray 21 . The guide wall 22 is fixed to the loading tray 21 and positions the paper. A support shaft 23 , which is the main body of the conveyance device, is attached to the guide wall 22 . The support shaft 23 extends leftward from the guide wall 22 and is connected to an electric motor (not shown) via a gear train. A pick-up unit 24 for conveying paper toward the recording device 13 (see FIG. 1 ) is supported on the support shaft 23 .

Moreover, the roller 25 (refer FIG. 6) which contacts a paper is provided in the loading surface 21a, and the paper contacts this loading surface 21a. The support surface 21b is provided with a separation pad 26 as a separation mechanism for separating the sheets one by one. The separation pad 26 includes a rectangular box-shaped case 26a attached to the support surface 21b, and a separation portion 26b extending in the front-back direction of the case 26a at the center of the case 26a in the left-right direction. A member having a higher coefficient of friction than the case 26a is used for the separating portion 26b.

As shown in FIG. 3 , the pick-up unit 24 includes: a first arm 31 mounted on the support shaft 23 and capable of rotating; a second arm 32 mounted on the lower end of the first arm 31 capable of rotating; The feed roller 33. A torsion coil spring 35 as an urging portion is attached to the second arm 32 . As a result, the feed roller 33 (second arm 32 ) is urged toward the paper P. As shown in FIG. Further, the feed roller 33 transmits the rotational force of the support shaft 23 via a transmission mechanism 34 composed of driven gears 34 a to 34 c. The torsion coil spring 35 is provided with a coil portion 35a, a first engaging portion 35b of a straight arm portion that is an end at which the coil portion 35a starts to be wound, and an L end that is an end at which the coil portion 35a is wound. The letter-shaped second engaging portion 35c.

The first arm 31 includes a pair of first arm portions 41 separated in the left-right direction, and an upper cover portion 42 connecting the first arm portions 41 to each other and covering the support shaft 23 from above. In each first arm portion 41 , a first bearing portion 43 having a through-hole penetrating through the arm portion 41 in the left-right direction is provided at a position above the first arm portion 41 . A first shaft portion 44 protruding rightward from the right arm portion 41 is provided at a portion below the right first arm portion 41 . A second bearing portion 45 having a through hole penetrating through the arm portion 41 in the left-right direction is provided at a portion below the first arm portion 41 on the left side. The support shaft 23 is slidably inserted into the first bearing portion 43 . In this embodiment, the "first rotation part 61" is comprised by the support shaft 23 and the 1st bearing part 43. As shown in FIG.

The upper cover portion 42 is provided with an arc-shaped curved portion 42 a that surrounds the first rotation portion 61 from the outside and is centered on the rotation center of the first rotation portion 61 . The bent portion 42 a is provided within the turning range of the first arm 31 . Here, in the conveyance device 12, the maximum loading capacity of paper (the maximum number of loaded sheets) is limited by the gap G (see FIG. 6) formed between the curved portion 42a and the loading surface 21a. Since the bending portion 42a does not change the size of the gap G due to the rotation of the first arm 31, the maximum loading capacity of the used paper is always kept constant by the rotation of the first arm 31.

The upper cover part 42 is provided with the protrusion part 42b which protrudes rightward rather than the 1st arm part 41 on the right side. A groove portion 42c recessed toward the rear is provided on the inner surface of the rear portion of the protruding portion 42b.

The second arm 32 includes a pair of second arm portions 51 separated in the left-right direction, and a cover body 52 covering the upper side and the front side of the second arm portion 51 . A protrusion 53 having a through hole passing through the arm 51 is provided above the right second arm 51 and protrudes rightward from the arm 51 . A cylindrical second shaft portion 54 protruding leftward of the left arm portion 51 is provided above the left second arm portion 51 . The lower portion of each second arm portion 51 is provided with a third bearing portion 55 that is a through hole penetrating the arm portion 51 in the left-right direction. The second arm 32 is attached to the first arm 31 by slidably inserting the second shaft portion 54 into the second bearing portion 45 and slidably inserting the first shaft portion 44 into the protrusion 53 . In the present embodiment, the second shaft portion 54 and the second bearing portion 45 constitute the “second rotation portion 62 ”, and the protrusion portion 53 and the first shaft portion 44 constitute the left “second rotation portion 62 ”. ".

The torsion coil spring 35 coaxial with the second rotation portion 62 is fitted into the protrusion portion 53 .

In addition, in front of the protruding portion 53 of the second arm portion 51 on the right side, a spring fixing portion 70 is arranged in an arc shape centered on the rotation center of the second rotating portion 62 and extends from the wrist. The portion 51 is constituted by a plurality of ribs 76 extending rightward. The rib 76 is formed in a rectangular shape extending radially around the rotation center of the second rotating portion 62 in a plan view viewed from the right.

The first engaging portion 35 b of the torsion coil spring 35 is inserted between adjacent ribs 76 . In addition, the second engaging portion 35c of the torsion coil spring 35 fits into the groove portion 42c of the upper cover portion 42 and is inserted into an insertion hole (not shown) provided in the first arm portion 41 .

The feed roller 33 is provided with a roller main body portion 33 a that fits with the third bearing portion 55 and is formed in a cylindrical shape. The sliding contact member 33b is attached to the outer peripheral surface of this roller main body part 33a, and this sliding contact member 33b is a cylindrical rubber member which abuts on paper. The gear part 33c (refer FIG. 4) which meshes with the driven gear 34c is provided in the left end of the roller main body part 33a.

As shown in FIG. 4, the transmission mechanism 34 is comprised by driven gears 34a-34c. The driven gear 34 a is mounted to rotate integrally with the support shaft 23 . The driven gear 34b meshes with both the driven gears 34a and 34c. The driven gear 34c meshes with the gear portion 33c. Also, as shown by the hollow arrow in the figure, if the driven gear 34a rotates counterclockwise along with the counterclockwise rotation of the support shaft 23, the driven gear 34b rotates clockwise due to the rotation of the driven gear 34a and the The driving gear 34c rotates counterclockwise. Also, the feed roller 33 rotates clockwise due to the rotation of the driven gear 34c.

As shown in FIG. 5 , the spring fixing portion 70 is provided with first to fifth adjustment portions 71 to 75 formed between adjacent ribs 76 . The biasing force of the torsion coil spring 35 is adjusted by engaging the first engaging portion 35b of the torsion coil spring 35 with any one of the first adjustment portion 71 to the fifth adjustment portion 75 described above. Here, the first adjustment part 71 to the fifth adjustment part 75 are formed in this order from the bottom to the top. The biasing force becomes the minimum when the torsion coil spring 35 engages with the first adjusting portion 71 . On the other hand, the biasing force becomes maximum when the torsion coil spring 35 engages with the fifth adjusting portion 75 . In addition, the biasing force of the torsion coil spring 35 increases from the first adjustment portion 71 to the fifth adjustment portion 75 .

When the first engaging portion 35b is changed from being engaged with the third adjusting portion 73 to engaging with the fourth adjusting portion 74 in order to increase the biasing force of the torsion coil spring 35, the dotted line in the figure As shown, the operator makes the first engaging portion 35b disengage from the third adjusting portion 73 by elastically deforming the first engaging portion 35b to the right of the third adjusting portion 73 . Then, the torsion coil spring 35 is twisted clockwise around the second rotating portion 62 and engaged with the fourth adjusting portion 74 . Similarly, when changing from engaging with the third adjusting portion 73 to engaging with the second adjusting portion 72 in order to reduce the biasing force of the torsion coil spring 35, the operator moves the first engaging portion 35b toward the third adjusting portion. After the right side of 73 is elastically deformed, the torsion coil spring 35 is twisted counterclockwise around the second rotating part and locked with the second adjusting part 72 .

Next, the loading to conveyance of the paper P by the conveyance device 12 will be described with reference to FIGS. 6 to 9 . Moreover, each figure (b) is a schematic diagram which respectively shows the relationship of the force which acts on the periphery of the pick-up unit 24, and the angle which the pick-up unit 24 forms. In FIGS. 6 to 8 , as the paper P, "plain paper" which is relatively thin and flexible paper is used.

Before the paper P is loaded on the loading tray 21 , the pickup unit 24 is disposed so that the feed roller 33 comes into contact with the loading surface 21 a. Here, the pick-up unit 24 is formed such that the first inter-axial distance D1 connecting the rotation center of the first rotation part 61 and the rotation center of the second rotation part 62 is smaller than the second inter-axis distance D2. The second interaxial distance D2 is the length of a straight line connecting the rotation center of the second rotating portion 62 and the rotation axis J of the feed roller 33 (see FIG. 6( b )).

As shown in FIG. 6, when the paper P is placed on the loading tray 21, the paper P is placed on the upstream side of the feed roller 33 in the conveyance direction, and the paper P is moved toward the downstream side by using the paper P. The paper P abuts against the feed roller 33 . Therefore, the component force of the weight of the paper P along the loading surface 21 a acts on the feed roller 33 . Thus, as shown by the dotted line in the figure, the above-mentioned component force is used to generate a force that makes the pick-up unit 24 rotate clockwise around the first rotating part 61, so the first arm 31 and the second arm 32 of the pick-up unit 24 are The first rotating part 61 integrally rotates clockwise around the center. In addition, the feed roller 33 is separated from the placement surface 21a, and the paper P passes through the gap between the feed roller 33 and the placement surface 21a. As a result, the paper P comes into contact with the separation pad 26 and the feed roller 33 comes into contact with the uppermost surface of the paper P. As shown in FIG.

As shown by the solid line in FIG. 6 , in the standby state in which the paper P is placed on the loading tray 21 and the rotation of the feed roller 33 is stopped, the pick-up unit 24 is maintained in a state where the torsion coil spring 35 is used to The first arm 31 is inclined forward as it goes downward, and the second arm 32 is inclined rearward as it goes downward.

However, when the number of sheets P is small, the pickup unit 24 changes from the state of the pickup unit 24 indicated by the dotted line in FIG. That is, in the pickup unit 24 , the first arm 31 is centered on the first turning portion 61 , and the lower end of the first arm 31 turns toward the paper P (counterclockwise in the drawing). Along with this, the second arm 32 maintains the inclination angle with respect to the first arm 31 , that is, the first arm 31 and the second arm 32 rotate toward the paper P integrally.

Also, in the standby state, the torsion coil spring 35 becomes a natural length. Therefore, the torsion coil spring 35 does not generate a force that urges the second arm 32 in the counterclockwise direction. That is, the second arm 32 does not generate a force (hereinafter referred to as " Applying force S"). Therefore, the feed roller 33 is only in contact with the paper P1. In addition, since the feed roller 33 has no tendency to rotate, the frictional force applied by the paper P1 to the feed roller 33 , that is, the roller friction force f is "0".

Here, the arm angle A, which is the angle formed by the first arm 31 and the second arm 32 in the standby state, is taken as the reference angle A1. Then, the acute angle formed by the straight line JL connecting the second rotating portion 62 and the rotation axis J of the feed roller 33 in the standby state and the mounting surface 21 a, that is, the contact surface of the paper P1 and the feed roller 33 That is, the inclination angle B is used as the reference angle B1.

As shown in FIG. 7 , in the state before the paper P1 is conveyed by the rotation of the feed roller 33 (the state just before conveyance), the paper P1 and the first paper that is in contact with the paper P1 in the stacking direction The inter-paper friction force F generated between the two papers P2 to be conveyed becomes maximum (hereinafter referred to as "inter-paper friction force F1"). In addition, the separation load H that is the load for the separation pad 26 to separate the paper P1 from the paper P2 becomes the maximum (hereinafter referred to as "separation load H1"). Accordingly, in order to convey the paper P1, a force corresponding to the resultant force of the frictional force F1 between the papers and the separation load H1 is required, and therefore the force T for conveying the paper P1 generated by the rotation of the feed roller 33 becomes maximum (hereinafter referred to as is "delivery force T1"). In addition, since the roller frictional force f corresponds to the reaction force of the conveyance force T1, it becomes the same magnitude as the conveyance force T1 in the state immediately before conveyance.

At this time, in the pick-up unit 24 , a force to rotate the arm 32 clockwise is applied to the second arm 32 due to the roller friction force f. Thereby, the lower end of the first arm 31 turns counterclockwise around the first turning portion 61 and the upper end of the second arm 32 turns clockwise around the rotation axis J of the feed roller 33 . As a result, the second turning part 62 moves toward the paper P. As shown in FIG. With such movement of the second turning portion 62, the arm angle A becomes an angle A2 (A1<A2) larger than the reference angle A1, and the inclination angle B becomes an angle B2 smaller than the reference angle B1 (B2<B1) . With the above-mentioned changes in the arm angle A and the inclination angle B, the feed roller 33 moves downstream in the transport direction of the paper P compared to the standby state. Accordingly, the provision force S1 is applied toward the downstream side in the transport direction compared to the virtual provision force SK when the provision force S1 is assumed to be applied in the standby state.

On the other hand, the torsion coil spring 35 bends in a direction opposite to the urging direction as the second turning portion 62 turns. Along with this, the restoring force R1 of the torsion coil spring 35 is applied to the second arm 32 . That is, the biasing force S1 corresponding to the above-mentioned restoring force R1 is applied to the second arm 32 . Accordingly, as the arm angle A increases from the reference angle A1, the torsion coil spring 35 bends to the opposite side of the urging direction, and thus the restoring force R1 of the torsion coil spring 35 increases.

Here, since the inclination angle B is the angle B2, the force (f·sinB2) that bites the feed roller 33 into the paper P1 due to the roller friction force f is smaller than the angle B1 of the inclination angle B assumed in the standby state. Similarly, the force (f·sinB1) of the feeding roller 33 biting into the paper P1 when the roller friction force f is generated, that is, f·sinB2<f·sinB1.

As shown in FIG. 8 , in the state where the paper P1 is conveyed relative to the paper P2 (paper conveyance state), the frictional force F2 between the paper P1 and the paper P2 becomes smaller than that of FIG. 6( b ). The frictional force F1 in the state before conveyance is small (F2<F1). In addition, since the paper P1 is separated from the paper P2, the separation load H is "0". Accordingly, in order to maintain the conveyance state of the paper P1, a force equivalent to the frictional force F2 is required, so the conveyance force T2 in the paper conveyance state becomes smaller than the conveyance force T1 (T2<T1). Accordingly, the roller frictional force f is equivalent to the conveyance force T2, and thus becomes smaller than that in the state immediately before conveyance.

At this time, in the pick-up unit 24 , the lower end of the first arm 31 rotates clockwise and the upper end of the second arm 32 rotates counterclockwise along with the reduction of the roller friction force f. Thereby, the second turning part 62 moves toward the paper P. As shown in FIG. As a result, the arm angle A becomes an angle A3 between the angle A1 and the angle A2 (A2<A3<A1). Also, the inclination angle B becomes an angle B3 between the angle B1 and the angle B2 (B1<B3<B2). Accompanying the above-mentioned changes in the arm angle A and the inclination angle B, the feed roller 33 moves to the upstream side compared to the state immediately before conveyance and to the downstream side compared to the standby state.

In addition, since the torsion coil spring 35 bends in the same direction as the urging direction with the rotation of the second rotation part 62, the restoring force R2 at this time becomes smaller than the restoring force R1 (R2<R1). Accordingly, the applying force S2 becomes smaller than the applying force S1 (S2<S1).

In this manner, in the pickup unit 24 , the roller frictional force f, the conveying force T, the applying force S, and the inclination angle B change, respectively, as the standby state transitions to the paper conveying state. That is, as the conveying force T (roller friction force f) increases, the applying force S increases, but the inclination angle B decreases.

However, even if the thickness of the paper P is different, the roller friction force f, the applying force S, the conveying force T, and the inclination angle B also vary respectively. That is, when the thickness of the paper P is different, since the separation load H changes, the roller friction force f changes. Specifically, with regard to the separation load H shown in FIG. 9 , in the case of thick paper P3 such as “photograph paper” or “postcard”, it is thinner than plain paper as shown in FIG. 7 . Compared with the paper P1, the separation load H becomes larger. Along with this, when the paper P3 is conveyed in the state immediately before conveyance, the roller friction force f becomes larger than when the paper P1 is conveyed. As a result, the conveyance force T3 of the paper P3 becomes larger than the conveyance force T1, so the angle B4 when the paper P3 is conveyed becomes smaller than the reference angle B1 when the paper P1 is conveyed (B4<B1).

According to the above-described embodiment, the following effects can be achieved.

(1) Since the biasing force of the torsion coil spring 35 can be adjusted by the first adjustment part 71 to the fifth adjustment part 75, it is possible to suppress the torsion caused by the unevenness of the spring force of the torsion coil spring 35 itself or the installation error. Variation in biasing force of the coil spring 35 . This suppresses the pressure contact force of the feed roller 33 against the paper P1 from becoming excessively large, thereby suppressing multi-feeding of the paper P.

(2) When the second arm 32 is rotated relative to the first arm 31 , the torsion coil spring 35 is elastically deformed, and the torsion coil spring 35 urges the feed roller 33 toward the paper P, so that the second arm 32 relative to the first arm 31 without turning, and the first arm 31 and the second arm 32 are integrally turned around the first turning portion 61 , the imparting force S becomes larger. In this configuration, when the paper P is inserted between the feed roller 33 and the mounting surface 21a, the first arm 31 and the second arm 32 are moved in the first direction by the force of the paper P pressing the feed roller 33 . The rotating portion 61 integrally rotates around the center. This suppresses an increase in the applying force S, and therefore suppresses an increase in the force with which the feed roller 33 presses the paper P. As shown in FIG. This makes it possible to easily place the paper P on the transport device 12 .

(3) When the second rotating part 62 is provided with a mechanism for limiting the number of sheets of paper P loaded, the second rotating part 62 is accompanied by the first arm 31 and the second arm 31 under the condition that the paper P is conveyed by the feed roller 33 . The rotation of the arm 32 moves toward the paper P or moves away from the paper P, so that the position of the second turning portion 62 with respect to the placement surface 21 a changes. As a result, the position of limiting the number of loaded sheets of paper P changes. Therefore, it cannot be clearly defined to what extent the paper P can actually be placed.

Regarding this point, in the present invention, since the curved portion 42a of the upper cover portion 42 covers the first rotating portion 61 from the outside in the rotational radial direction of the first rotating portion 61, when the first rotating portion 61 rotates, the curved portion 42a faces The position on the mounting surface 21a does not change either. Therefore, even when the paper P is conveyed by the feed roller 33, the positions of the placement surface 21a and the curved portion 42a do not change. Thereby, the maximum loading capacity of the paper P (number of loaded sheets) can be clearly limited.

(4) The curved portion 42a of the upper cover portion 42 is provided in the range where the first arm 31 rotates, so that the paper P is prevented from falling out of the gap G formed between the mounting surface 21a and the curved portion 42a during the rotation of the first arm 31. .

(5) The first engaging portion 35 b can be held on the rib 76 only by hooking the first engaging portion 35 b on the rib 76 , so when the operator adjusts the spring force of the torsion coil spring 35 , only the second An engaging portion 35b can be adjusted by being detached from the rib 76 and then mounted on the rib 76 . Therefore, the operator can easily perform the operation of adjusting the spring force of the torsion coil spring 35 .

(6) The pick-up unit 24 has the first rotating portion 61 and the second rotating portion 62 , and the torsion coil spring 35 that biases the second arm 32 is attached to the second rotating portion 62 . Accordingly, in the state immediately before conveyance and the paper conveyance state, the component force of the roller friction force f is applied to the second arm 32 as a force for rotating the second arm 32 clockwise. Utilizing this force, as the first arm 31 rotates counterclockwise around the first turning portion 61 and the second arm 32 turns clockwise around the rotation axis J of the feed roller 33 , the second turning portion 62 moves toward the Move with paper P. Accordingly, the inclination angle B becomes smaller with the rotation of the second rotation part 62 than in the standby state.

In addition, the torsion coil spring 35 generates a restoring force by the rotation of the second rotating part 62 , and the torsion coil spring 35 applies a force to the second arm 32 in the direction of the paper P by the restoring force of the torsion coil spring 35 . of giving power. This biasing force increases in proportion to the increase in the restoring force of the torsion coil spring 35 .

Therefore, the biasing force applied by the torsion coil spring 35 to the second arm 32 increases, but the inclination angle B decreases, so that the degree of increase of the roller friction force f is smaller than that of the aforementioned biasing force. As a result, it is possible to suppress the roller frictional force f from becoming too large relative to the inter-paper frictional force F, so that multifeeding of the papers P can be suppressed.

However, along with the miniaturization of printers, the demand for miniaturization of conveying devices is also increasing. In response to this requirement, miniaturization of the pickup unit is considered. That is, it is considered to achieve miniaturization by shortening the length of the arm 130 as shown in FIG. 10 . However, when the length of the arm 130 is shortened, the acute angle formed by the arm 130 and the loading surface 111 becomes larger than the acute angle X shown in FIG. Therefore, in order to suppress the above-mentioned biting, it is necessary to reduce the above-mentioned acute angle, so that the arm 130 needs to be lengthened, that is, the position of the drive shaft 140 needs to be arranged higher. However, in this case, there is a problem of increasing the size of the conveying device.

Regarding this point, in this embodiment, by inclining the second arm 32 relative to the first arm 31, the position of the support shaft 23 is not changed, and the inclination angle B corresponding to the above-mentioned acute angle is adjusted by the rotation of the second turning part 62. Since the frictional force f of the roller decreases with an increase, the occurrence of the above-mentioned biting can be suppressed. Therefore, both the downsizing of the conveyance device 12 and the suppression of the above-mentioned biting can be achieved at the same time.

In particular, in the transport device 100 shown in FIG. 10, the acute angle (inclination angle B) changes according to the loaded amount of the paper Q, and is set so as to have no relationship with the separation load of the paper Q or the frictional force between the papers. . As a result, when the loaded amount of paper Q is small, the frictional force (roller friction force) exerted by the paper Q on the feed roller 120 increases although the separation load or the frictional force between the papers does not change.

In this regard, in this embodiment, since the inclination angle B is changed according to the conveyance force T composed of the separation load H and the friction force F between the sheets, it is possible to suppress the inclination of the feed roller 33 due to the roller friction force f. The biting force (f·sinB) of the paper P1 becomes too large.

(7) Depending on the type of paper, even if the number of sheets is the same, the magnitude of the separation load H differs. For example, between plain paper and postcards, since postcards are thicker than plain paper, the separation load H becomes higher. In contrast, in the conveying device 100 shown in FIG. 10 , the position of the feed roller 120 can be adjusted according to the number of sheets of paper, but the pressing force of the feed roller 120 to the paper cannot be changed according to the type of paper. . Therefore, in the conveyance device 100 , for example, when the separation load H of postcards is set as a reference, when the number of sheets of plain paper is small, the plain paper may be multi-fed. On the other hand, when the separation load H of plain paper is set as a reference, when the number of sheets of thick paper is small, the conveyance force T of the feed roller 33 is insufficient, and the feed roller 33 may idle.

Regarding this point, in the present embodiment, since the pickup unit 24 increases the applying force S according to the increase of the separation load H, when the paper P is a thick paper such as a postcard, the conveyance of the feed roller 33 is increased. Force T. On the other hand, since the pickup unit 24 decreases the applying force S according to the decrease of the separation load H, the conveying force T decreases when the paper P is thin paper such as plain paper. Thereby, even when the separation load H varies due to the thickness of the paper P, it is possible to suppress the feed roller 33 from double-feeding the paper P or the feed roller 33 from idling.

(8) By making the first inter-shaft distance D1 smaller than the second inter-shaft distance D2 , the second rotating portion 62 can rotate more than when the first inter-shaft distance is larger than the second inter-shaft distance. Accordingly, it is possible to increase the range in which the force applied to the paper P1 by the feed roller 33 can be adjusted by the restoring force of the torsion coil spring 35 .

(9) In the state immediately before conveyance, the frictional force F between sheets of paper and the separation load H become maximum respectively, so the conveyance force T becomes maximum. In contrast, since the second turning portion 62 turns to minimize the inclination angle B, an increase in the roller friction force f can be suppressed. Therefore, it is possible to suppress the feeding roller 33 from biting the paper P1.

(10) As the application force S increases, the feed roller 33 moves downstream in the conveyance direction of the paper P, thereby shortening the distance between the feed roller 33 and the separation pad 26 . As a result, the toughness of the paper P becomes relatively stronger when the front end of the paper P comes into contact with the separation pad 26 , which facilitates the separation of the paper P.

In addition, since the applied force S goes downstream with an increase in the applied force S, the degree of increase in the upstream component of the applied force S becomes smaller than the degree of increase in the applied force S. As a result, the degree of increase in the roller frictional force f becomes smaller relative to the degree of increase in the applied force S. As shown in FIG. Therefore, it is possible to suppress the feeding roller 33 from biting the paper P1.

(11) In the state immediately before conveyance as shown in FIG. 7 or FIG. 9 , the second turning portion 62 restricts the turning movement to a position away from the paper P1, P3. Thereby, even if the second turning part 62 is turned toward the papers P1 and P3 , contact with the papers P1 and P3 can be avoided, and thus the papers P1 and P3 can be properly conveyed by the conveyance device 12 .

In addition, the above-mentioned embodiment may be changed as follows.

In the above embodiment, the first interaxial distance D1 between the first rotating portion 61 and the second rotating portion 62 may be formed to be equal to the distance D1 between the second rotating portion 62 and the rotation axis J of the feed roller 33 . The second inter-axis distance D2 is the same or greater.

- In the above embodiment, the release liner 26 may be omitted.

- In the said embodiment, the conveyance direction of the paper P may be the direction along the front-back direction. In this case, the feed roller 33 is in contact with the upper surface of the paper P. As shown in FIG. In addition, in the standby state, the second arm 32 inclines upward toward the upstream side in the conveyance direction. The first arm 31 inclines downward as it goes upstream in the transport direction. Then, when the state is just before the paper is conveyed, the arm angle A increases and the inclination angle B decreases. As a result, the feed roller 33 moves toward the downstream side in the conveying direction. Along with the movement of the feed roller 33 , the restoring force R of the torsion coil spring 35 increases, thereby increasing the biasing force S of the feed roller 33 . Also, in the sheet conveyance state, the arm angle A decreases and the inclination angle B increases compared to the state immediately before the sheet is conveyed. Thereby, the feed roller 33 moves toward the upstream side in the conveying direction. Accordingly, since the restoring force R of the torsion coil spring 35 decreases, the biasing force S of the feed roller 33 decreases.

- In the above embodiment, the torsion coil spring 35 may be attached to the first arm 31 . In this case, by attaching both ends of the torsion coil spring 35 to the first arm 31 and the second arm 32 , the restoring force R of the torsion coil spring 35 increases and decreases as the second rotating portion 62 rotates. .

- In the above-mentioned embodiment, the pick-up unit 24 may be attached to a part of the loading tray 21 or other parts of the printer 11 . In this case, the above-mentioned parts and the first bearing part 43 constitute the first rotating part. In addition, in this case, the above-mentioned portion may be formed in a shape corresponding to the first bearing portion 43 , and a shaft portion fitted to the above-mentioned portion may be provided on the first arm 31 .

· In the above embodiment, the spring fixing portion 70 may be provided on the first arm 31 . In this case, the second engaging portion 35 c is formed in a linear shape, and is engaged with the spring fixing portion 70 .

- In the above-mentioned embodiment, the curved portion 42 a of the upper cover portion 42 may be provided in a range smaller than the rotation range of the first rotation portion 61 . In addition, the bent portion 42a may also be omitted.

- In the above-mentioned embodiment, the biasing force of the torsion coil spring 35 is adjusted in five stages of the first adjustment part 71 to the fifth adjustment part 75, but the number of adjustment steps is not limited as long as it is a plurality of steps.

- In the said embodiment, as the to-be-conveyed medium conveyed by the conveyance apparatus 12, other than plain paper, a photographic paper, and a postcard, OHP etc. may be conveyed, for example.

- In the above-mentioned embodiment, the conveyance device 12 is not limited to be applicable only to the inkjet printer 11, and may be applied to, for example, a dot impact printer, a laser printer, a thermal transfer recording printer, and the like. In addition, the present invention is not limited to printers, and may be applied to other devices that convey media to be conveyed.

Claims (5)

1. A conveying device, characterized in that, possesses: The main body of the conveying device, which uses the feed roller to convey the conveyed medium; a first arm, which is installed on the main body of the conveying device, and can rotate relative to the main body of the conveying device around the first rotating part; The second arm is installed on the first arm, and can rotate relative to the first arm around the second rotating part, and becomes the same as the first rotating part relative to the second rotating part. The opposite side is fixed with said feed roller; a torsion coil spring acting on the second rotating portion in such a manner as to urge the feed roller toward the conveyed medium, A first fixing portion is provided on the first arm, and the first fixing portion fixes one end of the torsion coil spring, A second fixing portion is provided on the second arm, and the second fixing portion fixes the other end of the torsion coil spring, A plurality of spring hooking parts are provided on at least one of the first fixing part and the second fixing part, and the spring hooking parts are used to adjust the spring force of the torsion coil spring. 2. The delivery device of claim 1, wherein: The torsion coil spring is elastically deformed according to the rotation of the second arm relative to the first arm, whereby the torsion coil spring urges the feed roller toward the conveyed medium. 3. The delivery device of claim 1, wherein: A mounting surface on which the conveyed medium is mounted is provided at a position facing the feed roller of the conveying device, A cover is provided at a portion of the first rotating portion facing the conveyed medium, and the cover covers the first rotating portion from an outer side in a radial direction of rotation of the first rotating portion, The number of loaded sheets of the conveyed medium is limited by a gap formed between the loading surface and the cover. 4. The delivery device of claim 3, wherein: The cover is provided in a range where the first arm rotates in accordance with an operation of the feed roller that feeds the conveyed medium. 5. The delivery device of claim 1, wherein: The torsion coil spring is provided with a linear arm portion at least one of a winding start portion and a winding end portion of the wound coil portion, The plurality of spring hooks are composed of a plurality of ribs, the arm is mounted to the rib, The spring force of the torsion coil spring is adjusted by changing the rib on which the arm is mounted.

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