JP2012192699A - Driving force transmission device to cutter mechanism of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow normal clutch operation by allowing an one-way clutch to reliably run idle when operating a cutter mechanism.SOLUTION: A load mechanism (a projection 17 and a flat spring 18) is provided at a predetermined place of a driving force transmission device for transmitting driving force to a movable blade driving gear 106, a worm gear 11, a worm wheel 13, and a movable blade 14 from a one-way clutch. The load mechanism gives a rotation-suppressing load to a second gear of the one-way clutch when a first gear thereof is rotated in the direction where a torsion spring arranged in the inner part of the one-way clutch is loosened. When the first gear is rotated, the rotation-suppressing load is applied to the second gear by the load mechanism to thereby separate the torsion spring from a ring. Thus, the second gear does not rotate with the first gear but reliably runs idle so that the driving force is not transmitted to the cutter mechanism from the second gear.

Description

  The present invention relates to a driving force transmission device to a cutter mechanism of a printing apparatus, and is particularly suitable for a driving force transmission device provided with a one-way clutch in a printing device with a cutter mechanism for cutting a roll-shaped recording paper. .

  2. Description of the Related Art Conventionally, a printing apparatus has been provided in which a roll-shaped recording paper is printed by a printing mechanism while being conveyed by a paper feeding mechanism, and then the recording paper is cut to a required length by a cutter mechanism. In this type of printing apparatus, the recording paper is fed by rotating the platen roller with a motor while the recording paper is pressed against the platen roller of the paper feeding mechanism. The recording paper can be cut by sliding the movable blade in the direction of the fixed blade with a motor while the recording paper is passed between the fixed blade and the movable blade of the cutter mechanism. This is done by sandwiching the recording paper.

  Usually, a motor for rotating the platen roller of the paper feed mechanism and a motor for sliding the movable blade of the cutter mechanism are provided separately. In addition, there is a type in which the driving of the platen roller and the driving of the movable blade are performed by one motor for the purpose of cost reduction. When the drive source is a single motor as in the latter, it is common to switch between driving of the platen roller and driving of the movable blade in accordance with the rotation direction of the motor. That is, the platen roller is driven when the motor rotates in one direction, and the movable blade is driven when the motor rotates in the other direction.

  In order to switch between driving of the platen roller and driving of the movable blade according to the rotation direction of the motor, a mechanism called a one-way clutch is used (for example, see Patent Document 1). FIG. 10 is a diagram illustrating a configuration example of a driving force transmission device using a one-way clutch. In FIG. 10, 101 is a motor shaft, 102 is a motor gear, 103 is a transport system one-way clutch, 104 is a roller drive gear, 105 is a cutter system one-way clutch, and 106 is a movable blade drive gear.

  FIG. 11 is a diagram illustrating a configuration example of the cutter one-way clutch 105. As shown in FIG. 11, the cutter one-way clutch 105 is configured by overlapping a first gear 105a and a second gear 105b. A columnar ring 105c is provided at the center of the second gear 105b, and a torsion spring 105d is disposed around the ring 105c. A foot 105e is provided at one end of the torsion spring 105d, and this fits into a groove (not shown) provided on the inner surface of the first gear 105a. As a result, the first gear 105a and the torsion spring 105d rotate integrally.

  When the first gear 105a of the cutter one-way clutch 105 is rotated in the direction in which the torsion spring 105d inside the second gear 105b is tightened, the torsion spring 105d is tightly tightened against the ring 105c of the second gear 105b. As a result, the first gear 105a, the torsion spring 105d, and the second gear 105b all rotate integrally.

  On the other hand, when the first gear 105a of the cutter type one-way clutch 105 is rotated in the direction in which the torsion spring 105d inside the second gear 105b is loosened, the torsion spring 105d can move freely away from the ring 105c of the second gear 105b. It becomes a state. As a result, only the first gear 105a and the torsion spring 105d rotate as a unit, and the second gear 105b remains stopped (idling state).

  Although not shown, the transport system one-way clutch 103 is configured in the same manner as the cutter system one-way clutch 105. That is, the transport system one-way clutch 103 is configured by overlapping the first gear 103a and the second gear 103b. A columnar ring (not shown) is provided in the center of the second gear 103b, and a torsion spring (not shown) is disposed around the ring. A foot (not shown) is provided at one end of the torsion spring, and this fits into a groove (not shown) provided on the inner surface of the first gear 103a.

  As shown in FIG. 10, the motor gear 102 meshes with both the first gear 103 a of the transport system one-way clutch 103 and the first gear 105 a of the cutter system one-way clutch 105. Further, the second gear 103 b of the transport system one-way clutch 103 is engaged with the roller drive gear 104, and the second gear 105 b of the cutter system one-way clutch 105 is engaged with the movable blade drive gear 106.

  For example, when the motor is rotated clockwise, both the first gear 103a of the transport system one-way clutch 103 and the first gear 105a of the cutter system one-way clutch 105 rotate counterclockwise. At this time, the rotation of the first gear 103a of the transport system one-way clutch 103 is assumed to be rotation in a direction in which the torsion spring in the second gear 103b is tightened. In this case, the torsion spring is tightly tightened against the ring, and the second gear 103b rotates following the first gear 103a. As a result, the driving force is transmitted from the second gear 103b to the roller driving gear 104, and the paper feed mechanism is activated.

  On the other hand, the rotation of the first gear 105a of the cutter one-way clutch 105 is a rotation in the direction in which the torsion spring 105d inside the second gear 105b is loosened. In this case, the torsion spring 105d is free to move away from the ring 105c, and the second gear 105b idles (does not rotate following the first gear 105a). As a result, the driving force is not transmitted from the second gear 105b to the movable blade driving gear 106, and the cutter mechanism does not operate.

  Conversely, when the motor is rotated counterclockwise, both the first gear 103a of the transport system one-way clutch 103 and the first gear 105a of the cutter system one-way clutch 105 rotate in the clockwise direction. At this time, the rotation of the first gear 103a of the transport system one-way clutch 103 is a rotation in the direction in which the torsion spring inside the second gear 103b is loosened. In this case, the torsion spring is free to move away from the ring, and the second gear 103b idles. As a result, the driving force is not transmitted from the second gear 103b to the roller driving gear 104, and the paper feed mechanism does not operate.

  On the other hand, the rotation of the first gear 105a of the cutter one-way clutch 105 is a rotation in a direction in which the torsion spring 105d inside the second gear 105b is tightened. In this case, the torsion spring 105d is tightened with respect to the ring 105c, and the second gear 105b rotates following the first gear 105a. Accordingly, the driving force is transmitted from the second gear 105b to the movable blade driving gear 106, and the cutter mechanism is activated.

Japanese Patent No. 3730153

  As described above, in order for the one-way clutch to operate normally, the second gear needs to idle completely when the first gear rotates in the direction in which the torsion spring loosens. However, when a high-precision torsion spring cannot be used for cost reduction or the like, even when the first gear rotates in the loosening direction of the torsion spring, the torsion spring does not completely separate from the ring, and the second gear However, there is a problem that the first gear may follow the first gear.

  This problem is unlikely to occur in the transport system one-way clutch 103 and is likely to occur in the cutter system one-way clutch 105. A problem that hardly occurs in the transport system one-way clutch 103 is that the recording paper is sandwiched between the thermal head of the printing mechanism and the platen roller of the paper feeding mechanism, and tension is always applied. This is because an appropriate external load is applied to the second gear 103b of the transport system one-way clutch 103. In other words, the external load transmitted from the platen roller to the second gear 103b can keep the second gear 103b stopped, and the torsion spring rotates by the rotation of the first gear 103a in the loosening direction of the torsion spring. Since the spring is loosened, tightening of the torsion spring with respect to the ring is reduced, so that only the first gear 103a rotates and the second gear 103b normally idles.

  On the other hand, in the case of the cutter type one-way clutch 105, there is almost no external load applied to the second gear 105b. Therefore, even when the first gear 105a rotates in the loosening direction of the torsion spring 105d, the state where the torsion spring 105d tightens the ring 105c is maintained, and the second gear 105b is driven by the first gear 105a. The problem of rotating easily occurs.

  The present invention has been made to solve such a problem. When the first gear is rotated in the direction in which the torsion spring is loosened, the second gear is surely idled so that the one-way clutch is operated normally. The purpose is to enable operation.

  In order to solve the above-described problem, in the present invention, the one-way clutch is disposed inside the one-way clutch at a predetermined position in the driving force transmission system that transmits the driving force to the movable blade via the movable blade driving mechanism. A load mechanism is provided that applies a rotation suppression load to the second gear when the first gear of the one-way clutch is rotated in the direction in which the torsion spring is loosened.

  According to the present invention configured as described above, even when the torsion spring is not completely separated from the ring when the first gear of the one-way clutch is rotated in the direction in which the torsion spring is loosened, Since the mechanism applies a rotation suppression load to the second gear as an appropriate external load, the external gear can keep the second gear stopped. Accordingly, when the first gear is rotated in the direction in which the torsion spring is loosened, only the first gear is rotated, the second gear is idled, and the one-way clutch can be operated normally.

It is a figure which shows the structural example of the driving force transmission apparatus to the cutter mechanism by this embodiment. It is a figure which shows the internal structural example of the cutter unit by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the modification of the load mechanism by this embodiment. It is a figure which shows the structural example of the driving force transmission apparatus using a one-way clutch. It is a figure which shows the structural example of a cutter type | system | group one-way clutch.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration example of a driving force transmission device to a cutter mechanism according to the present embodiment. In FIG. 1, 101 is a motor shaft, 102 is a motor gear, 103 is a transport system one-way clutch, 104 is a roller drive gear, 105 is a cutter system one-way clutch, and 106 is a movable blade drive gear. These are all the same as those shown in FIGS. In the present embodiment, the movable blade drive mechanism includes the movable blade drive gear 106, the worm gear 11, the worm wheel 13, and the drive shaft 12 shown in FIG.

  Reference numeral 10 denotes a cutter unit as a cutter mechanism. 2A and 2B are diagrams showing an example of the internal configuration of the cutter unit 10, wherein FIG. 2A is a perspective view, FIG. 2B is a top view, FIG. 2C is a front view, and FIG. 2D is a partially enlarged view of the front view. It is. In FIG. 2, reference numeral 11 denotes a worm gear that interlocks with the movement of the movable blade drive gear 106 and is attached to the drive shaft 12. Reference numeral 13 denotes a worm wheel that meshes with the worm gear 11, and reference numeral 14 denotes a movable blade connected to the worm wheel 13 via a link 19.

  In the present embodiment, the cutter system one-way clutch 105 and the movable blade drive gear 106 are operated by rotating the motor (not shown) with the above configuration. When the movable blade drive gear 106 operates, the drive shaft 12 attached to the movable blade drive gear 106 and the worm gear 11 attached to the drive shaft 12 operate. The worm gear 11 is formed with a spiral groove, and the groove and the worm wheel 13 are engaged with each other. As a result, the driving force is transmitted to the worm wheel 13 via the worm gear 11 so that the worm wheel 13 rotates. The movable blade 14 connected to the worm wheel 13 is driven. When the worm wheel 13 is rotated once in the direction of the arrow A, the movable blade 14 slides in the direction of the arrow B and makes one reciprocation between the home position and the cut position.

  When the driving force is transmitted from the motor to the roller drive gear 104 via the transport system one-way clutch 103 and the recording paper is transported, the second gear 105b of the cutter system one-way clutch 105 is idled to move the movable blade drive gear 106. No driving force is transmitted to the movable blade 14, and the movable blade 14 stands by at the home position (position shown in FIG. 2).

  On the other hand, when the driving force is transmitted from the cutter system one-way clutch 105 to the movable blade drive gear 106, the worm wheel 13 rotates once in the direction of the arrow A, and the movable blade 14 reciprocates once between the home position and the cut position. . At this time, the second gear of the transport system one-way clutch 103 is idled so that no driving force is transmitted to the roller drive gear 104, and a platen roller (not shown) for transporting the recording paper does not rotate.

  On the worm wheel 13, a home position detection cam 15 (hereinafter referred to as an HP detection cam) of the movable blade 14 is provided. The HP detection cam 15 has a notch 15a in part. A sensor 16 (hereinafter referred to as an HP detection sensor) for detecting the home position of the movable blade 14 is provided at a position facing the notch 15a. The HP detection sensor 16 has a protruding lever 16a, and detects that the movable blade 14 is at the home position when the notch 15a reaches the position of the lever 16a.

  In the present embodiment, a load mechanism is provided at a predetermined location in the driving force transmission system from the cutter system one-way clutch 105 to the movable blade 14. This load mechanism is applied to the second gear 105b of the cutter one-way clutch 105 when the first gear 105a of the cutter one-way clutch 105 is rotated in the direction in which the torsion spring 105d provided in the cutter one-way clutch 105 is loosened. On the other hand, it is for giving rotation suppression load.

  Specifically, the load mechanism includes a protrusion 17 provided on the worm wheel 13 and a rotation suppressor that contacts the protrusion 17 and applies a rotation suppression load to the second gear 105b of the cutter one-way clutch 105. And a leaf spring 18 as a member. The leaf spring 18 is supported by a cutter frame (not shown) of the cutter unit 10.

  When the rotation of the worm wheel 13 in the direction of the arrow A is a forward rotation, the convex portion 17 includes a surface 17a on the forward rotation side (right side of FIG. 2D) and a left side of the reverse rotation side (FIG. 2D). ) Surface 17b (hereinafter referred to as contact surface) is formed by an inclined surface having a taper of an angle smaller than 90 degrees. The tip of the leaf spring 18 is bent in an L shape in accordance with the taper angle of the contact surface 17b. The tip of the leaf spring 8 is preferably formed so as to be in contact with the contact surface 17b substantially in parallel. With such a configuration, when the worm wheel 13 tries to rotate in the direction opposite to the arrow A, the contact surface 17b of the convex portion 17 comes into contact with the tip of the leaf spring 18, and the worm gear 13 is movable from the worm wheel 13. A rotation suppression load is applied to the second gear 105b of the cutter one-way clutch 105 via the blade driving gear 106.

  The convex portion 17 on the worm wheel 13 is provided at a position where the leaf spring 18 contacts the contact surface 17b when the movable blade 14 is at the home position. That is, when the worm wheel 13 rotates once in the direction of the arrow A, the convex portion 17 moves away from the leaf spring 18 immediately after the start of rotation. Then, at the end of one rotation, the convex portion 17 approaches the leaf spring 18, and the convex portion 17 returns to the original position through the movement of the leaf spring 18 over the convex portion 17. Note that the surface 17a on the forward rotation side of the protrusion 17 is formed by an inclined surface having a smaller taper than the contact surface 17b on the reverse rotation side so that the leaf spring 18 can get over the protrusion 17 as smoothly as possible. Is preferred.

  In addition, when the worm wheel 13 rotates once, the position and size of the protrusion 17 are set so that the protrusion 17 that moves with the rotation does not interfere with the main body of the HP detection sensor 16 and the lever 16a. Is done. That is, the convex portion 17 is provided at a position and a size that can pass through the space below the lever 16 a of the HP detection sensor 16. In this embodiment, the convex portion 17 is provided along the circumferential portion of the HP detection cam 15. However, as long as the convex portion 17 does not interfere with the HP detection sensor 16, a position away from the circumferential portion (the outer circumference of the worm wheel 13 is You may provide the convex part 17 in the near side.

  The operation of the driving force transmission device to the cutter mechanism according to the present embodiment configured as described above will be described below. For example, when a motor (not shown) is rotated counterclockwise, both the first gear 103a of the transport system one-way clutch 103 and the first gear 105a of the cutter system one-way clutch 105 are rotated clockwise. At this time, the rotation of the first gear 103a of the transport system one-way clutch 103 is a rotation in the direction in which the torsion spring inside the second gear 103b is loosened. In this case, the torsion spring is free to move away from the ring.

  Further, since the recording paper is sandwiched between the thermal head of the printing mechanism and the platen roller of the paper feeding mechanism and the tension is always applied, the second gear 103b of the transport system one-way clutch 103 passes from the platen roller through the roller driving gear 104. A moderate external load is applied. An external load transmitted from the platen roller to the second gear 103b becomes a rotation restraining load on the second gear 103b, and only the first gear 103a rotates and the second gear 103b rotates idly. As a result, the driving force is not transmitted from the second gear 103b to the roller driving gear 104, and the paper feed mechanism does not operate.

  On the other hand, the rotation of the first gear 105a of the cutter one-way clutch 105 is a rotation in a direction in which the torsion spring 105d inside the second gear 105b is tightened. In this case, the torsion spring 105d connected to the first gear 105a is tightened tightly against the ring 105c of the second gear 105b, and the second gear 105b rotates following the first gear 105a. Accordingly, the driving force is transmitted from the second gear 105b to the movable blade driving gear 106, and the cutter mechanism is activated.

  When the driving force is transmitted to the movable blade drive gear 106, the worm gear 11 and the worm wheel 13 rotate, and the movable blade 14 slides to reciprocate between the home position and the cut position. At this time, the worm wheel 13 rotates in the direction of arrow A in FIG. Thereby, the convex portion 17 moves away from the leaf spring 18 immediately after the rotation of the worm wheel 13 starts. Finally, when the leaf spring 18 gets over the convex portion 17, the rotation of the worm wheel 13 is finished.

  When the leaf spring 18 gets over the convex portion 17, the leaf spring 18 comes into contact with the surface 17a on the positive rotation side of the convex portion 17, but the surface 17a on the positive rotation side has a smaller inclination angle than the contact surface 17b. , No heavy load due to contact. Since the magnitude of the load is negligibly small compared to the magnitude of the driving force by the motor, the rotation of the worm wheel 13 is not inhibited and the worm wheel 13 can smoothly rotate to the end. . That is, the movable blade 14 can be slid with almost no load.

  Conversely, when the motor is rotated clockwise, both the first gear 103a of the transport system one-way clutch 103 and the first gear 105a of the cutter system one-way clutch 105 rotate counterclockwise. In this case, the torsion spring connected to the first gear 103a is tightly tightened against the ring of the second gear 103b, and the second gear 103b rotates following the first gear 103a. As a result, the driving force is transmitted from the second gear 103b to the roller driving gear 104, and the paper feed mechanism is activated.

  On the other hand, the rotation of the first gear 105a of the cutter one-way clutch 105 is a rotation in the direction in which the torsion spring 105d inside the second gear 105b is loosened. In this case, the torsion spring 105d is free to move away from the ring 105c. However, the second gear 105b of the cutter type one-way clutch 105 is not subjected to an external load such as a tension from the recording paper sandwiched between the thermal head and the platen roller, so that the torsion spring 105d is removed from the ring 105c. If it is not completely separated, the second gear 105b may follow the first gear 105a.

  If the second gear 105b rotates following the first gear 105a, the worm wheel 13 rotates in the direction opposite to the arrow A. On the other hand, in the present embodiment, a load mechanism including the convex portion 17 and the leaf spring 18 is provided, and a load is applied to the worm wheel 13 rotating in the direction opposite to the arrow A. The rotation suppression load on the worm wheel 13 is transmitted to the second gear 105b via the worm gear 11. As a result, only the first gear 105a rotates and the second gear 105b idles. As a result, the driving force is not transmitted from the second gear 105b to the movable blade driving gear 106, and the cutter mechanism is not operated.

  As described above in detail, in the present embodiment, when the first gear 105a is rotated in the direction in which the torsion spring 105d disposed inside the cutter one-way clutch 105 is loosened, the rotation suppression load is applied to the second gear 105b. As a load mechanism for providing the above, a convex portion 17 and a leaf spring 18 are provided. Therefore, when the first gear 105a is rotated in the direction in which the torsion spring 105d is loosened, only the first gear 105a is rotated to reliably idle the second gear 105b, and the cutter one-way clutch 105 can be operated normally. it can.

  In the present embodiment, both the forward rotation side surface 17a and the reverse rotation side surface 17b of the convex portion 17 are formed by inclined surfaces having a taper of an angle smaller than 90 degrees. In particular, the contact surface 17b on the reverse rotation side is also tapered to form an inclined surface. If the contact surface 17b is also inclined, the worm wheel 13 can be rotated in the direction opposite to the arrow A without damaging the convex portion 17 and the leaf spring 18 by applying a certain force or more. That is, it is possible to allow the worm wheel 13 to reversely rotate so that the leaf spring 18 rides on the convex portion 17.

  If the contact surface 17b is not inclined and is perpendicular to the worm wheel 13, the convex portion 17 and the leaf spring 18 may be damaged when the worm wheel 13 is forcibly reversely rotated with a certain force or more. There is a risk. For example, an operation unit for manually rotating the worm gear 11 is provided, and when a paper jam occurs during cutting of the recording paper, the user manually operates the operation unit to mesh with the worm gear 11. There is a case where the worm wheel 13 is forced to reversely rotate. Even in such a case, according to the present embodiment, the worm gear 11 and the worm wheel 13 are rotated in the reverse direction by manually operating the operation unit without damaging the convex portion 17 and the leaf spring 18, thereby causing a paper jam. Can be eliminated.

  In the present embodiment, the load mechanism is configured by providing the convex portion 17 on the worm wheel 13 only at one location. When the leaf spring 18 gets over the convex portion 17 at the end of one rotation of the worm wheel 13, the plate spring 18 hits the worm wheel 13 and makes a “click” sound. Can be suppressed to the minimum once.

  In the above embodiment, the example in which the convex portion 17 is provided on the worm wheel 13 has been described. However, as shown in FIG. 3, a concave portion 17 ′ may be provided instead of the convex portion 17. The concave portion 17 ′ in this case is also formed by an inclined surface having a taper with an angle smaller than 90 degrees on the surface 17 a ′ on the forward rotation side and the surface 17 b ′ on the reverse rotation side of the worm wheel 13. However, contrary to the case of the convex portion 17, the surface 17 a ′ on the forward rotation side of the concave portion 17 ′ is in contact with the tip of the leaf spring 18. The reverse-rotation-side surface 17b 'of the recess 17' is preferably formed by an inclined surface having a taper with a smaller angle than the forward-rotation-side contact surface 17a 'for applying a rotation suppression load.

  In the above-described embodiment, the example in which the taper angle of the surface 17a on the positive rotation side of the convex portion 17 is made smaller than the taper angle of the contact surface 17b on the reverse rotation side has been described, but the taper angle of each surface 17a, 17b is It may be the same. For example, the same taper angle as that of the contact surface 17b may be attached to the surface 17a on the positive rotation side. In this way, the load applied when the leaf spring 18 gets over the convex portion 17 at the end of the worm wheel 13 rotating once in the forward rotation direction is slightly increased, but the worm wheel 13 is rotated by obtaining a large driving force of the motor. Therefore, the leaf spring 18 can get over the convex portion 17 without any problem.

  On the other hand, when the first gear 105a rotates in the direction in which the torsion spring 105d is loosened, the second gear 105b is essentially idled and no driving force is transmitted to the worm wheel 13. However, if the second gear 105b tries to rotate following the first gear 105a in a state where the torsion spring 105d is not completely separated from the ring 105c, a part of the driving force of the motor is transmitted to the worm wheel 13. End up. However, in this case, the driving force transmitted to the worm wheel 13 is smaller than the driving force transmitted when the worm wheel 13 is rotated forward, and even if the worm wheel 13 tries to reversely rotate by the driving force, the leaf spring 18 is convex. Can't get over part 17. That is, the contact surface 17b of the convex portion 17 comes into contact with the tip of the leaf spring 18 and a rotation suppression load sufficient to prevent reverse rotation of the worm wheel 13 can be applied.

  Moreover, although the said embodiment provided the convex part 17 on the worm wheel 13, and demonstrated the example which uses the leaf | plate spring 18 as a rotation suppression tool made to contact this convex part 17, this invention is not limited to this. For example, as shown in FIG. 4, a compression spring 21 and a pressure contact member 22 may be used instead of the leaf spring 18.

  The pressure contact member 22 has a hollow portion whose upper side is open, and a part of the compression spring 21 is inserted into the hollow portion. The side surface 22 a on the positive rotation side of the pressure contact member 22 is tapered in accordance with the inclination angle of the contact surface 17 b of the convex portion 17. One end of the compression spring 21 is fixed to the cutter frame 23, and the other end is fixed to the bottom surface of the hollow portion of the pressure contact member 22. Thus, the pressure contact member 22 receives a force (a force toward the lower side in FIG. 4) that the compression spring 21 tends to extend and presses against the worm wheel 13.

  When the worm wheel 13 is rotated forward, at the end of one rotation, the compression spring 21 inside the pressure contact member 22 contracts and gets over the convex portion 17. On the other hand, with respect to the direction in which the worm wheel 13 is rotated in the reverse direction, the contact surface 17b on the reverse rotation side of the convex portion 17 is in contact with the side surface 22a of the press-contact member 22 A rotation suppression load is applied to the second gear 105b of the cutter one-way clutch 105.

  Moreover, although the said embodiment demonstrated the example which provides the convex part 17 (or recessed part 17 ') on the worm wheel 13, this invention is not limited to this. For example, as shown in FIG. 5, a convex portion 31 (or a concave portion) may be provided on the worm gear 11. In the example of FIG. 5, a plurality of protrusions are provided on the worm gear 11 and the convex portion 31 is configured in a gear-like shape. A leaf spring 32 is provided at a position facing the convex portion 31 as a rotation suppression tool that contacts the convex portion 31 and applies a rotational suppression load to the second gear 105 b of the cutter one-way clutch 105. The leaf spring 32 is supported by a cutter frame (not shown).

  Each of the protrusions forming the gears of the convex portion 31 configured in this way is a surface of the worm gear 11 on the forward rotation (rotation in the direction of rotating the worm wheel 13) side and reverse rotation (reverses the worm wheel 13). The surface in the direction of rotation) is formed by an inclined surface having a taper with an angle smaller than 90 degrees. The surface on the reverse rotation side comes into contact with the leaf spring 32 to apply a rotation suppression load to the second gear 105b. Moreover, it is preferable that the surface on the forward rotation side of the convex portion 31 is formed by an inclined surface having a taper with a smaller angle than the surface on the reverse rotation side.

  Further, as shown in FIG. 6, a compression spring 41 may be incorporated in the drive shaft 12 of the worm gear 11, and a rotation suppression load may be applied to the second gear 105 b by the extension force of the compression spring 41. That is, the compression spring 41 is provided so as to be wound around the drive shaft 12 of the worm gear 11, and one end of the compression spring 41 is brought into contact with the cutter frame and the other end is brought into contact with the worm gear 11. Thereby, a load is applied to the rotation of the worm gear 11 by the action of the compression spring 41, and a rotation suppression load is applied to the second gear 105b of the cutter one-way clutch 105 via the movable blade driving gear 106 meshing with the worm gear 11. It is done.

  Further, as shown in FIG. 7, the movable blade driving gear 106 may be provided with a convex portion 51 (or a concave portion). In the example of FIG. 7, a plurality of protrusions are provided on the movable blade drive gear 106, and the convex portion 51 is configured in a gear-like shape. A leaf spring 52 is provided at a position facing the convex portion 51 as a rotation suppression tool that contacts the convex portion 51 and applies a rotational suppression load to the second gear 105 b of the cutter one-way clutch 105. The leaf spring 52 is supported by a cutter frame (not shown).

  4 to 7, a load is applied to the sliding of the movable blade 14 even when the cutter mechanism is operated. In the modified examples of FIGS. 5 and 7, the inclination angle of the surface on the positive rotation side of the convex portions 31 and 51 is reduced so that the load is reduced, but a constant load is still applied. As a result, the cutting force by the movable blade 14 is reduced by the amount of load.

  On the other hand, in the embodiment shown in FIGS. 1 and 2, only one convex portion 17 is provided on the worm wheel 13. In addition, the convex portion 17 is provided at a position where the movable blade 14 contacts the leaf spring 18 when the movable blade 14 is at the home position. Therefore, when the movable blade 14 moves to the cut position and cuts the recording paper, the load due to the convex portion 17 is not applied, and a reduction in cutting force can be avoided.

As another embodiment of the present invention, for example, as shown in FIG. 8, a hole 61 provided in a part of the movable blade 14 and a second gear 105 b of the cutter one-way clutch 105 in contact with the hole 61. Alternatively, the load mechanism may be constituted by a leaf spring 62 as a rotation restraining tool that applies a rotation restraining load. The leaf spring 62 is supported by a cutter frame (not shown). The hole 61 and the leaf spring 62 are provided at a position where they contact when the movable blade 14 is at the home position.

  The hole 61 has a cross section 61a on the cut position side (upper side in FIG. 8) and a cross section 61b on the home position side (lower side in FIG. 8) of the arrow B with which the movable blade 14 slides. The cross section 61a on the cut position side is in contact with the cross section 61b on the home position side. In particular, since the cross section 61 b on the home position side is in contact with the leaf spring 62, a load due to friction or a load due to the elastic force of the leaf spring 62 is generated, and it rotates with respect to the second gear 105 b of the cutter one-way clutch 105. It is designed to give a restraining load. The leaf spring 62 is not necessarily in contact with the cross-section 61a on the cut position side of the hole 61, and the tip of the leaf spring 62 may not be bent as shown in FIG.

  In such a configuration, when the first gear 105a rotates in the direction in which the torsion spring 105d is tightened and the worm wheel 13 rotates forward, the leaf spring 62 gets over the section 61b of the hole 61 when the worm wheel 13 starts rotating. This is because the worm wheel 13 obtains a large driving force of the motor. On the other hand, when the first gear 105a rotates in the loosening direction of the torsion spring 105d and the worm wheel 13 tries to rotate in the reverse direction, the section 61b of the hole 61 and the leaf spring 62 are in contact with each other. In addition, a load due to the elastic force of the leaf spring 62 is generated, and the leaf spring 62 does not get over the cross section 61 b of the hole 61. This is because the driving force transmitted to the worm wheel 13 in this case is sufficiently smaller than the driving force transmitted when the worm wheel 13 is rotated forward.

  In addition, although the leaf | plate spring 62 is used here as a rotation suppression tool, it is not limited to this. For example, it is good also as a structure which provides a load by providing a processus | protrusion in cutter frame itself and the hole 61 of the movable blade 14 contacts a processus | protrusion. Moreover, it is good also as a structure which provides a taper in the cross section 61a by the side of the cut position of the hole 61, and the cross section 61b by the side of a home position. Alternatively, only the cross section 61b on the home position side may be in contact with the leaf spring 62.

  Further, as shown in FIG. 9, a hole 71 provided in a part of the link 19 that connects the worm wheel 13 and the movable blade 14, and the second gear 105 b of the cutter one-way clutch 105 comes into contact with the hole 71. On the other hand, a load mechanism may be configured by a leaf spring 72 as a rotation restraining tool that gives a rotation restraining load. The leaf spring 72 is supported by a cutter frame (not shown). The hole 71 and the leaf spring 72 are provided at a position where they contact when the movable blade 14 is at the home position.

  Similarly to the hole 61 shown in FIG. 8, the hole 71 configured in this way also has a cross-section 71 a on the cut position side (upper side in FIG. 9) and the home position side (in FIG. 9) on which the movable blade 14 slides. A lower section 71b is formed, and the leaf spring 72 is in contact with the section 71a on the cut position side and the section 71b on the home position side. In particular, since the cross section 71b on the home position side is in contact with the leaf spring 72, a load due to friction or a load due to the elastic force of the leaf spring 72 is generated, and the rotation is performed with respect to the second gear 105b of the cutter type one-way clutch 105. It is designed to give a restraining load. The leaf spring 72 is not necessarily in contact with the cross-section 71a on the cut position side of the hole 71, and the tip of the leaf spring 72 may not be bent.

  In this configuration, when the first gear 105a rotates in the direction in which the torsion spring 105d is tightened and the worm wheel 13 rotates forward, the leaf spring 72 gets over the cross section 71b of the hole 71 when the worm wheel 13 starts rotating. On the other hand, when the first gear 105a rotates in the loosening direction of the torsion spring 105d and the worm wheel 13 tries to reversely rotate, the section 71b of the hole 71 and the leaf spring 72 come into contact with each other, A load due to the elastic force of the leaf spring 72 is generated, and the leaf spring 72 does not get over the cross section 71 b of the hole 71.

  In addition, although the leaf | plate spring 72 is used as a rotation suppression tool also in FIG. 9, it is not limited to this. For example, it is good also as a structure which provides a protrusion by providing a processus | protrusion in cutter frame itself and the hole 71 of the link 19 contacts a processus | protrusion. Moreover, it is good also as a structure which provides a taper in the cross section 71a by the side of the cut position of the hole 71, and the cross section 71b by the side of a home position, and a taper is good also as an inclined surface smaller than 90 degree | times. Further, only the cross section 71b on the home position side may be in contact with the leaf spring 72.

  Moreover, although the movable blade 14 gave and demonstrated the example of the guillotine system in the said embodiment, this invention is not limited to this. For example, the movable blade may be a scissor method or a pizza cutter method. In short, the present invention can be applied as long as there is a part that rotates when the driving force is transmitted to the movable blade.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 11 Worm gear 12 Drive shaft 13 Worm wheel 14 Movable blade 15 HP detection cam 16 HP detection sensor 17 Convex part 17a Surface on the normal rotation side of convex part 17b Surface on the reverse rotation side of convex part (contact surface)
17 'concave portion 17a' surface on the positive rotation side of the concave portion (contact surface)
17b ′ Reverse rotation side surface of concave portion 18 Leaf spring 19 Link 21 Compression spring 22 Pressure contact member 31 Convex portion 32 Plate spring 41 Compression spring 51 Convex portion 52 Plate spring 61 Hole 62 Plate spring 71 Hole 72 Plate spring

Claims (5)

A one-way clutch having a configuration in which a first gear and a second gear are stacked, and a torsion spring disposed around a ring provided inside;
A movable blade drive gear meshing with the one-way clutch;
A movable blade drive mechanism interlocked with the movable blade drive gear,
The movable blade drive mechanism is driven by the driving force transmitted to the one-way clutch and the movable blade drive gear, and the movable blade connected to the movable blade drive mechanism is driven.
A load mechanism that applies a rotation suppression load to the second gear when the first gear is rotated in a direction in which the torsion spring is loosened at a predetermined position in the driving force transmission system from the one-way clutch to the movable blade. A driving force transmission device to the cutter mechanism of the printing apparatus, further comprising: The movable blade drive mechanism includes a worm gear attached to a drive shaft and interlocking with the movable blade drive gear, a worm wheel meshing with the worm gear, and further coupled to the movable blade.
The load mechanism includes a convex portion provided on the worm wheel, and a rotation suppression tool that contacts the convex portion and applies the rotation suppression load to the second gear,
The convex portion is formed by an inclined surface having a taper of an angle smaller than 90 degrees on the forward rotation side surface and the reverse rotation side surface of the worm wheel, and the reverse rotation side surface is the rotation suppressor. The driving force transmission device to the cutter mechanism of the printing apparatus according to claim 1, wherein the rotation suppression load is applied to the second gear in contact with the second gear. The cutter mechanism of the printing apparatus according to claim 2, wherein the surface on the forward rotation side of the convex portion is formed by an inclined surface having a taper having a smaller angle than the surface on the reverse rotation side. Driving force transmission device. The movable blade drive mechanism includes a worm gear attached to a drive shaft and interlocking with the movable blade drive gear, a worm wheel meshing with the worm gear, and further coupled to the movable blade.
The load mechanism includes a recess provided on the worm wheel, and a rotation suppressor that contacts the recess and applies the rotation suppression load to the second gear,
The concave portion is formed by an inclined surface having a taper of an angle smaller than 90 degrees on the surface on the forward rotation side and the surface on the reverse rotation side of the worm wheel, and the surface on the positive rotation side is formed with the rotation suppressor. The driving force transmission device to the cutter mechanism of the printing apparatus according to claim 1, wherein the rotation suppression load is applied to the second gear by contact. The surface of the reverse rotation side of the concave portion is formed by an inclined surface having a taper having an angle smaller than that of the surface of the normal rotation side. Driving force transmission device.

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