CN217753256U - Printing unit with cutter and printer - Google Patents

Abstract

Provided is a printing unit with a cutter, the printing unit being provided with a drive rack coupled to a movable blade and a return mechanism for moving the movable blade from a cutting position to a standby position when a mechanical coupling with a drive motor is disconnected, the return mechanism being provided with a coil spring (150), the coil spring (150) having a coil portion (153) wound spirally around a coil axis (O2) from a 1 st coil end (151) to a 2 nd coil end (152) with the coil axis being the center, a 1 st latching end (154) bent so as to extend outward in the radial direction of the coil portion from the 1 st coil end, and a 2 nd latching end (155) bent so as to extend outward in the radial direction of the coil portion from the 2 nd coil end, the coil spring being mounted in a state in which the 1 st latching end is latched to a return gear and the 2 nd latching end is latched to a fixed member.

Description

Printing unit with cutter and printer

Technical Field

The present invention relates to a printing unit with a cutter and a printer.

Background

Conventionally, in various stores and the like, a Point of sale (POS) system capable of managing POS is used as a device for inputting sales and issuing a charge, a payment, a receipt, and the like. Such a POS system is constituted by, for example, a display device such as a POS terminal, a printer, a liquid crystal display, and a peripheral device such as a cash drawer.

In general, many printers constituting a POS system include a thermal printer (printing unit with a cutter) including a cutter mechanism for cutting printed recording paper. The cutter mechanism often has an automatic cutter function of automatically cutting the recording paper after printing on the recording paper is completed, for example.

The cutter mechanism includes a fixed blade and a movable blade, and the movable blade is slidably moved so as to be pressed against the upper surface of the fixed blade, thereby pinching and cutting the recording paper. However, in such a cutter mechanism, when the recording paper is cut, the fixed blade and the movable blade may bite each other, for example, when the recording paper is jammed between the fixed blade and the movable blade. In this case, the movable knife is unintentionally brought into a state in which it does not operate (cutter lock), and therefore, it is necessary to quickly return from the cutter lock state to a normal state in which it can operate normally.

As a means for performing such restoration, for example, a method is known in which a worm wheel is rotated by a tool or the like to forcibly slide and move a movable knife to a home position (see japanese patent application laid-open No. 2006-075935). Further, the following printers are also known: the movable knife is retracted from the fixed knife in accordance with the opening operation of the cover member, and the cutter lock state can be released without using a tool or the like (see japanese patent application laid-open No. 2004-237555).

Similarly, as a printer capable of releasing the cutter lock state without using a tool or the like, the following printer with a cutter is known (see japanese patent application laid-open No. 2010-549): the cutter can be unlocked by separating the fixed unit in which the fixed blade is incorporated from the movable unit in which the movable blade is incorporated in conjunction with the operation of the lever. In the printer with a cutter, the mechanical coupling between the rack attached to the movable blade and the drive gear is disconnected in accordance with the operation of the lever portion, and the movement restriction of the rack is released. When the restriction on the movement of the rack is released, the movable knife is moved to the home position via the rack by the elastic restoring force of the coil spring (torsion coil spring).

However, as in the invention described in japanese patent application laid-open No. 2006-075935, the method of forcibly returning the movable blade to the home position by rotating the worm wheel with a tool or the like requires that the worm wheel be continuously rotated by several tens of turns. Therefore, not only is it troublesome and burdens the operator, but also it takes time to recover the work.

In this regard, in the case of the invention described in japanese patent application laid-open No. 2004-237555, the cutter lock state can be released by opening the lid member without using a tool or the like, and therefore, the method is simple. However, in a case where the lid member itself cannot be opened, it becomes difficult to release the cutter lock state. For example, due to a paper jam of the recording paper, the platen unit attached to the cover member may be locked with respect to the housing or the main unit attached to the housing, and the cover member itself cannot be opened. Therefore, in this case, it becomes difficult to release the cutter lock state.

In contrast, in the case of the printer with a cutter described in japanese patent application laid-open No. 2010-549, since the fixed unit and the movable unit can be separated in conjunction with the operation of the lever, the cutter lock state can be released without interfering with the opening operation of the cover member. However, the coil spring is susceptible to an unintended large stress (stress) due to repeated operation, and it is sometimes difficult to exhibit stable operation performance over a long period of time, and there is room for improvement.

Specifically, the coil spring is disposed between a gear meshing with the rack and a support member rotatably supporting the gear, and the 1 st locking end is locked to the gear side and the 2 nd locking end is locked to the support member side. Each time the movable blade slides, the gear rotates with the movement of the rack. Thus, this action is shown as follows: the coil spring is repeatedly elastically deformed in a winding and unwinding manner whenever the movable blade is slidingly moved. In particular, the coil spring is configured to be elastically deformed in a wound manner when the movable blade moves toward the fixed blade. Thus, when the cutter is in the locked state, the coil spring can be elastically restored and deformed so as to be unwound in association with the operation of the lever. Thus, the gear is rotated by the elastic restoring force of the coil spring, and the movable knife is moved to the home position so as to retract the movable knife from the fixed knife.

However, the 1 st locking end portion of the coil spring is often bent from a coil portion in which a bare wire (a straight line) is spirally wound so as to extend along the axis of the coil spring. Therefore, in the coil spring, when the gear rotates, the rotation torque from the gear is easily transmitted to the most distal end portion of the 1 st locking end portion, and the coil spring is easily moved while being largely inclined with respect to the axis line and elastically deformed. In particular, in a state of an installation posture inclined with respect to the axis, for example, if the coil spring is elastically deformed in a wound manner, not only the work easily becomes unstable, but also unintended pressure is easily accumulated while the elastic deformation is repeatedly generated. As a result, when such a coil spring is used, the coil spring is likely to receive unintended repetitive stress, and it becomes difficult to exhibit stable operation performance, and there is a risk that, for example, redundancy for a predetermined number of operation requests may vary.

The present invention has been made in view of such circumstances, and an object thereof is to provide a printing unit with a cutter and a printer as follows: the coil spring can be stably operated for a long period of time, and even if the cutter locking state occurs, the cutter locking state can be properly and quickly released.

Disclosure of Invention

(1) The printing unit with a cutter according to the present invention is characterized by comprising: a movable blade driving mechanism having a driving rack coupled to a movable blade that cuts the recording paper in cooperation with a fixed blade and a rack gear that meshes with the driving rack and rotates in accordance with rotation of a driving motor, the movable blade moving between a standby position spaced apart from the fixed blade and a cutting position pressed against the fixed blade; and a return mechanism having a return gear that meshes with the rack gear, and that moves the movable blade from the cutting position to the standby position when the mechanical coupling between the rack gear and the drive motor is disconnected, wherein the return mechanism includes a coil spring that has a coil portion that is wound in a spiral shape around a coil axis from a 1 st coil end to a 2 nd coil end, a 1 st locking end portion that is bent from the 1 st coil end so as to extend outward in a radial direction of the coil portion, and a 2 nd locking end portion that is bent from the 2 nd coil end so as to extend outward in the radial direction of the coil portion, and the coil spring is attached in a state in which the 1 st locking end portion is locked to the return gear and the 2 nd locking end portion is locked to a fixing member.

According to the cutter-equipped print unit of the present invention, the movable blade can be moved from the standby position (home position) to the cutting position by the movable blade driving mechanism during normal operation. That is, the drive motor rotates the rack gear to move the drive rack and move the movable knife to the cutting position. This allows the recording paper to be cut between the movable blade and the fixed blade.

In the above-described normal operation, for example, when the fixed knife and the movable knife bite due to paper jam of the recording paper and fall into the cutter lock state, the mechanical coupling between the rack gear and the drive motor is disconnected, and the rack gear can be forcibly rotated in the reverse direction by the return mechanism. That is, the mechanical coupling between the rack gear and the drive motor is disconnected, and the rack gear and the drive rack can be transitioned to a free state in which the coupling with the drive motor is lost. Therefore, the return mechanism can forcibly rotate the rack gear in the reverse direction via the return gear to return the movable knife from the cutting position to the standby position, which is the home position. This makes it possible to appropriately cope with removal of a jammed portion of the recording paper, and to restore the cutter lock state.

In particular, the return gear is rotated in the reverse direction by the elastic restoring force of the coil spring (torsion coil spring), and the rack gear can be forcibly rotated in the reverse direction. Specifically, since the coil spring is attached in a state where the 1 st locking end is locked to the return gear and the 2 nd locking end is locked to the fixed member, the return gear rotates with the rotation of the rack gear and elastically deforms so as to wind up in the process of moving the movable blade from the standby position to the cutting position. Therefore, when the rack gear is shifted to the free state, the return gear can be rotated in the reverse direction by the elastic restoring force due to the elastic restoring deformation of the coil spring. As a result, the movable knife can be returned to the standby position.

However, since the return gear is meshed with the rack gear, the movable blade rotates forward and backward every time the movable blade moves between the standby position and the cutting position during normal operation. Therefore, the coil spring is repeatedly elastically deformed in a winding and unwinding manner in association with the forward and reverse rotation of the return gear. At this time, with respect to the coil spring, both the 1 st latching end portion and the 2 nd latching end portion are bent from the winding ends (the 1 st winding end and the 2 nd winding end) of the coil portion so as to extend outward in the radial direction of the coil portion. Therefore, the rotational torque transmitted from the return gear to the coil spring can be transmitted to the base end portion (the connecting portion between the 1 st locking end portion and the 1 st coil end) side of the 1 st locking end portion. Therefore, the point of transmission of the rotating torque can be shifted to the coil portion side compared to the conventional case where the 1 st locking end extends along the coil axis and the rotating torque is transmitted to the topmost end portion side of the 1 st locking end.

This allows the coil spring to be elastically deformed while suppressing the inclination with respect to the coil axis, and thus, the coil spring is less likely to receive unintended repetitive stress (pressure). Therefore, the durability of the coil spring can be improved, and the coil spring can be stably operated over a long period of time, and the predetermined operation request number can be sufficiently satisfied. Therefore, even if the cutter locked state occurs, the movable blade can be appropriately returned to the standby position by the elastic restoring force of the coil spring, and the cutter locked state can be appropriately and quickly released.

(2) The return mechanism may have a rotary shaft portion disposed coaxially with the coil axis and pivotally supporting the return gear, the coil spring may be disposed so as to surround the rotary shaft portion from the outside in the radial direction, and a locking hole that penetrates the return gear in the radial direction and locks the 1 st locking end portion in a state of being inserted through the inside may be formed in the return gear.

In this case, the coil spring is disposed so as to surround the rotation shaft from the outside in the radial direction, and the return gear is supported by the rotation shaft, so that the posture of the coil spring is easily stabilized, and the return gear can be rotated stably. Further, it becomes easy to smoothly assemble the coil spring and the return gear by the rotation shaft portion. Further, since the coil spring can be combined with the return gear in a state where the 1 st locking end is stably locked by the locking hole, the above-described operational effect can be appropriately exerted, and the cutter locked state can be appropriately released.

(3) The coil spring may be formed such that a circumferential direction position of the 1 st locking end portion along the circumferential direction of the coil portion and a circumferential direction position of the 2 nd locking end portion along the circumferential direction are the same.

In this case, the circumferential direction positions of the 1 st locking end and the 2 nd locking end can be made the same, and therefore, for example, the coil spring can be easily manufactured.

(4) The coil spring may be formed such that a circumferential direction position of the 1 st locking end portion along the circumferential direction of the coil portion and a circumferential direction position of the 2 nd locking end portion along the circumferential direction are different positions.

In this case, since the circumferential direction positions of the 1 st locking end and the 2 nd locking end are different, the present invention can be suitably used in a case where the circumferential direction position of the return gear is set to a determined position, for example, at the time of assembling the return gear.

(5) The present invention may further include: a 1 st unit having the fixed blade; a 2 nd unit having the movable blade and detachably combined with the 1 st unit; an operation lever operable between a lock position for locking the 2 nd unit with respect to the 1 st unit and an unlock position for unlocking the 2 nd unit with respect to the 1 st unit; and a release mechanism for disconnecting the mechanical coupling between the rack gear and the drive motor in accordance with an operation of the operating lever from the lock position to the lock release position, wherein one of the 1 st unit and the 2 nd unit has a platen roller, and the other unit has a thermal head.

In this case, when the cutter is trapped in the cutter lock state, the operation lever is operated from the lock position to the unlock position. Thus, the mechanical coupling between the rack gear and the drive motor can be disconnected by the release mechanism, and the rack gear and the drive rack can be transitioned to a free state in which the coupling with the drive motor is lost. Therefore, as described above, the return mechanism having the return gear can forcibly rotate the rack gear in the reverse direction and return the movable knife from the cutting position to the standby position as the home position. Therefore, by separating the 1 st unit and the 2 nd unit, which are unlocked, from each other, it is possible to appropriately cope with a situation where a jammed sheet of recording paper is removed, and it is possible to restore the cutter locked state. In particular, the release mechanism can be operated in conjunction with the operation of the operating lever to disconnect the mechanical coupling between the rack gear and the drive motor, and thus the cutter lock state can be further easily restored.

(6) The movable knife driving device may further include a pressing portion that moves the fixed knife in a direction away from the movable knife and releases a contact pressure between the fixed knife and the movable knife in response to the operation of the operating lever from the locked position to the unlocked position.

In this case, by operating the operating lever from the lock position to the unlock position, the fixed blade can be forcibly moved in the direction away from the movable blade pressed against the fixed blade by the pressing portion of the pressure release mechanism. This can release the contact pressure between the movable blade and the fixed blade. Therefore, the movable knife can be easily moved smoothly from the cutting position to the standby position, and the cutter lock state can be more effectively restored.

(7) The printer according to the present invention is characterized by comprising: the printing unit with a cutter; a printer main body that accommodates the recording paper; and a printer cover rotatably coupled with respect to the printer main body.

According to the printer of the present invention, since the printer unit with the cutter described above is provided, the printer can be easily used as a printer capable of appropriately recovering the cutter lock state.

Drawings

Fig. 1 is a perspective view of a thermal printer according to an embodiment of the present invention, and is a perspective view of a printer cover in a closed state.

Fig. 2 is a perspective view of the thermal printer shown in fig. 1 with the printer cover opened.

Fig. 3 is a perspective view of the embossing unit shown in fig. 2.

Fig. 4 is a perspective view showing the platen unit in a state where the platen cover is detached from the state shown in fig. 3.

Fig. 5 is a side view of the embossing unit shown in fig. 4.

Fig. 6 is a perspective view of the embossing unit shown in fig. 4.

Fig. 7 is a perspective view of the head unit shown in fig. 2.

Fig. 8 is a perspective view showing the head unit in a state where the head cover plate and the like are detached from the state shown in fig. 7.

Fig. 9 is a side view of the head unit shown in fig. 8 as viewed from one side wall portion side of the head frame.

Fig. 10 is a side view of the head unit shown in fig. 8 as viewed from the other side wall portion side of the head frame.

Fig. 11 is a perspective view showing a state where the recording paper is cut by the movable blade and the fixed blade.

Fig. 12 is a side view showing a state in which the movable knife is moved from the state shown in fig. 10 to the cutting position.

Fig. 13 is a perspective view showing the relationship of the operation lever, the swing plate, the release lever, and the like shown in fig. 8.

Fig. 14 is a perspective view of the swing plate, the 1 st rack gear, and the intermediate gear shown in fig. 8.

Fig. 15 is a side view of the swing plate, the 1 st rack gear, and the intermediate gear shown in fig. 14.

Fig. 16 is a perspective view of the head unit shown in fig. 8, and is a perspective view of the periphery of the operation lever as viewed from the guide table side.

Fig. 17 is a perspective view showing the relationship of the operation lever, the swing plate, the release lever, and the like shown in fig. 13.

Fig. 18 is a side view showing a state in which the operation lever is depressed from the state shown in fig. 9.

Fig. 19 is an enlarged perspective view of the periphery of the 2 nd rack gear and the return gear shown in fig. 10.

Fig. 20 is a perspective view showing a state where the return gear is detached from the state shown in fig. 19.

Fig. 21 is a perspective view of the return gear shown in fig. 19.

Fig. 22 is a perspective view of the return gear shown in fig. 19, in which a torsion coil spring is incorporated.

Fig. 23 is a sectional view of the return gear, the torsion coil spring, and the like shown in fig. 19.

Fig. 24 is a perspective view of the torsion coil spring shown in fig. 20.

Fig. 25 is a sectional view showing a state where the return gear rotates from the state shown in fig. 23 and the torsion coil spring is elastically deformed in a wound manner.

Fig. 26 is a sectional view showing a state in which the torsion coil spring is elastically deformed to be further wound from the state shown in fig. 24.

Fig. 27 is a perspective view showing an example of a conventional torsion coil spring.

Fig. 28 is a sectional view of the torsion coil spring shown in fig. 27 when incorporated into a return gear or the like.

Fig. 29 is a sectional view showing a state where the return gear rotates from the state shown in fig. 28 and the torsion coil spring is elastically deformed in a wound manner.

Fig. 30 is a perspective view showing a modification of the torsion coil spring of the present embodiment.

Fig. 31 is a perspective view showing another modification of the torsion coil spring according to the present embodiment.

Detailed Description

Embodiments according to the present invention will be described below with reference to the drawings. In the present embodiment, a thermal printer used in a POS system is exemplified. The POS system is a system for totaling sales results and the like of sales of articles sold in units of individual articles, and mainly includes an information processing device (not shown) and a thermal printer (printer according to the present invention) 1 shown in fig. 1. The POS system is installed in various stores such as convenience stores, retail stores, and restaurants, and can display various information including checkout information such as a name of a commodity or a price purchased by a customer in the stores to the customer.

Examples of the information processing device include, but are not limited to, a desktop personal computer and a tablet personal computer. The information processing apparatus and the thermal printer 1 are directly connected (wired connection) by a connection cable such as a USB (Universal Serial Bus) cable. However, the present invention is not limited to this, and the information processing apparatus and the thermal printer 1 may be connected wirelessly via a wireless communication means or the like, or may be connected via a network.

As shown in fig. 1 and 2, the thermal printer 1 is installed on an installation surface S at a store entrance, for example, and is formed in a cube shape as a whole. In the present embodiment, in the state shown in fig. 1 and 2, a direction perpendicular to the installation surface S is referred to as a vertical direction L1, and directions perpendicular to each other in a plane parallel to the installation surface S are referred to as a front-rear direction L2 and a left-right direction L3. The front side in the front-rear direction L2 is indicated by an arrow FW, and the rear side is indicated by an arrow BA. Therefore, in fig. 1 and 2, the lower left side is the front FW and the upper right side is the rear BA with respect to the paper.

The thermal printer 1 is a printer that can print on recording paper P such as thermal paper and use the recording paper P as a ticket, a receipt, or the like, and includes: a casing (printer main body according to the present invention) 2 that accommodates a roll-shaped recording paper P inside; a printer cover 3 rotatably coupled to the housing 2; and a cutter-equipped print unit 4 (hereinafter, simply referred to as a print unit 4) including a head unit 5 and a platen unit 6.

The thermal printer 1 of the present embodiment is of a so-called front-out type in which the recording paper P is discharged forward FW.

The housing 2 is formed in a cubic shape having an opening in the front FW by a synthetic resin material, a metal material, or an appropriate combination of these materials, and has a plurality of outer surfaces 10 including a bottom surface 11 facing the installation surface S. However, the shape of the housing 2 is not limited to this, and may be changed as appropriate.

An outer surface 10 of the plurality of outer surfaces 10 facing in the up-down direction L1 with respect to the bottom surface 11 is referred to as a top surface 12. Among the plurality of outer surfaces 10, the outer surface 10 located on the front FW side is referred to as a front surface 13, and the outer surface 10 located on the rear BA side is referred to as a rear surface 14. Therefore, the front surface 13 and the rear surface 14 face each other in the front-rear direction L2. Further, the outer surfaces 10 facing each other in the left-right direction L3 among the plurality of outer surfaces 10 are referred to as a pair of side surfaces 15.

A recording paper storage 16 is formed inside the casing 2, and the recording paper storage 16 can store the roll recording paper P through an opening formed in the front surface 13 of the casing 2. Thus, when the printer cover 3 is in the open state, the roll paper P can be fed from the front FW into the paper storage 16.

The printer cover 3 is coupled to a lower portion of the front surface 13 side of the housing 2 via a rotation shaft portion 17, and openably closes the opening. Further, the printer cover 3 is coupled so as to rotate within an angular range of substantially 90 degrees around the rotation shaft portion 17. As shown in fig. 1, when the printer cover 3 is in the closed state, a slight gap is provided between the top end of the printer cover 3 and the housing 2. The recording paper P is drawn forward FW from the inside of the housing 2 by the gap and discharged. Thus, the gap functions as the discharge port 18 of the recording paper P.

When the printer cover 3 is closed, the housing 2 and the printer cover 3 configured as described above are locked together with the combination of the platen unit 6 and the head unit 5. Thereby, the printer cover 3 is locked in the closed state.

Further, as shown in fig. 1 and 2, the housing 2 is provided with a lock release lever 20 for releasing the lock of the printer cover 3 and opening the printer cover 3 at a corner where the front surface 13, the top surface 12, and the one side surface 15 intersect. The lock release lever 20 can be depressed downward, for example, and the combination (lock) of the head unit 5 and the platen unit 6 can be released in association with the depression operation, whereby the printer cover 3 can be unlocked.

The lock release lever 20 is coupled to an operating lever 46, which will be described later, via a coupling member 21 disposed below the lock release lever 20. This allows the operation lever 46 to be operated from the lock position P3 to the unlock position in conjunction with the operation of the unlock lever 20. As a result, the lock shaft 55 described later can be disengaged from the lock groove 64, and the combination of the head unit 5 and the platen unit 6 can be released.

In the printer cover 3, an operation unit 25 having operation buttons 26 and an auxiliary board 27 is provided. The operation button 26 is, for example, a power button or a paper feed button, and is disposed in a state of being exposed to be depressible on the outer surface of the printer cover 3. The operation buttons 26 are arranged below the lock release lever 20 in a row in the vertical direction L1, for example.

The auxiliary board 27 is a board ON which a plurality of electronic components (not shown) or a switch (not shown) (for example, a membrane switch or the like) turned ON by pressing down the operation button 26 is mounted, and is electrically connected to a main board (not shown). Further, the main board comprehensively controls the operation of the thermal printer 1. The auxiliary substrate 27 is disposed on the inner surface side of the printer cover 3 and on the back side of the operation buttons 26, and is covered by a protective cover 28 mounted on the inner surface side of the printer cover 3.

As shown in fig. 1 and 2, the printing unit 4 includes a platen unit (1 st unit according to the present invention) 6 provided on the printer cover 3 side and a head unit (2 nd unit according to the present invention) 5 provided on the housing 2 side. These imprint unit 6 and head unit 5 are combined in such a manner as to be separable from each other. Note that the description of the printing unit 4 will be made based on each direction in the case where the printer cover 3 is in the closed state.

As shown in fig. 3 to 6, the imprint unit 6 includes at least: a platen roller 30 that feeds out the recording paper P; a fixed blade 31 disposed on the downstream side of the platen roller 30 in the transport direction of the recording paper P; an impression frame 32 that rotatably supports the impression roller 30; and a platen cover 33 combined with the platen frame 32 so as to cover the platen frame 32 from the front FW and the left-right direction L3.

The platen frame 32 is a member forming a basic framework of the platen unit 6, and is made of, for example, synthetic resin. The platen 33 is made of, for example, metal. However, the material of the platen frame 32 and the platen cover 33 is not limited to this, and may be changed as appropriate.

As shown in fig. 2, the platen unit 6 configured as described above is attached to the inner surface of the printer cover 3 mainly via the platen cover 33. At this time, the platen unit 6 is mounted at a position where it can be separated from the head unit 5 in accordance with the opening and closing operation of the printer cover 3. The platen unit 6 is attached such that the cutting edge 31a of the stationary blade 31 faces upward (see fig. 4).

As shown in fig. 7 and 8, the head unit 5 includes at least: a thermal head 40 for printing on the recording paper P; a movable blade 41 disposed on the downstream side of the thermal head 40 in the conveyance direction of the recording paper P; a head frame 42 that supports the respective constituent members; a head cover plate 43 combined with the head frame 42 so as to cover the head frame 42 from the front FW and the left-right direction L3; and a gear cover 44 combined with the head frame 42 so as to cover the head frame 42 from the left-right direction L3.

The head frame 42 is a member forming a basic framework of the head unit 5, and is made of, for example, synthetic resin. The head cover plate 43 and the gear cover 44 are made of, for example, metal. However, the materials of the head frame 42, the head cover plate 43, and the gear cover 44 are not limited to this, and may be appropriately changed.

As shown in fig. 2, the head unit 5 configured as described above is mounted inside the housing 2 mainly via the head frame 42. Specifically, the head unit 5 is disposed above the recording paper storage 16 and near the front surface 13 of the housing 2, and is attached to the housing 2 by screwing the head frame 42 to the top surface 12 or the like. The head unit 5 is attached so that the cutting edge 41a of the movable knife 41 faces downward (see fig. 8). Thereby, the cutting edge 31a of the fixed knife 31 and the cutting edge 41a of the movable knife 41 face each other in the vertical direction L1. The fixed blade 31 and the movable blade 41 also function as cutters for pinching and cutting the recording paper P.

The platen unit 6 and the head unit 5 will be described in detail below. First, the imprint unit 6 will be described in detail.

The platen unit 6 shown in fig. 3 to 6 is arranged such that, when combined with the head unit 5, the outer peripheral surface of the platen roller 30 is in contact with the thermal head 40 on the head unit 5 side with the recording paper P sandwiched therebetween. The platen frame 32 is formed with a pair of support walls 34 arranged to face each other in the left-right direction L3 and pivotally supporting the platen roller 30.

The platen roller 30 is rotatably supported by a support wall 34 via bearings 30b attached to both ends of a platen shaft 30a extending in the left-right direction L3. On one end side of the platen roller 30, a driven gear 35 is fixed in a state of being coupled to the platen shaft 30a with a bearing 30b interposed therebetween.

The fixed blade 31 is a plate-shaped blade extending in the width direction (i.e., the left-right direction L3) of the recording paper P, and is supported by the fixed blade holder 36 such that the blade edge 31a faces upward when the printer cover 3 is closed and faces the fed recording paper P. At this time, the fixed knife 31 is supported so that the cutting edge 31a side swings in the front-rear direction L2 (the direction substantially orthogonal to the sliding direction of the movable knife 41) as indicated by the arrow shown in fig. 4. An elastic member such as a coil spring, not shown, is provided between the fixed blade holder 36 and the fixed blade 31, and the elastic member biases the fixed blade 31 toward the front FW so as to be pushed up from the fixed blade holder 36. Thereby, the cutting edge 31a of the fixed blade 31 is biased toward the front FW so as to be always lifted from the fixed blade holder 36.

Between the fixed blade 31 and the platen 33, a shaft 50 extending in the left-right direction L3 is disposed on the root side of the fixed blade 31. The shaft 50 has both ends in the left-right direction L3 rotatably supported by bearing members 38 formed on the platen frame 32. A press-down portion 51 and a coupling piece 52 are coupled to one end side of the shaft 50, and only the press-down portion 51 is coupled to the other end side of the shaft 50.

As shown in fig. 5, the coupling piece 52 is formed in a fan shape in a side view as viewed from the left-right direction L3. A 1 st engagement projection 53 projecting upward toward the rear BA is formed on the outer peripheral surface of the connecting piece 52. When the printer cover 3 is closed, the 1 st engagement projection 53 comes into contact with or approaches from below a 2 nd engagement projection 91 (see fig. 9) of an operation lever 46 (described later) provided on the head unit 5 side. Therefore, the coupling piece 52 and the shaft 50 can be rotated in conjunction with the operation of depressing the operation lever 46.

As shown in fig. 4, the pressing portion 51 is coupled to the shaft 50 in such a manner as to be located inside the platen frame 32 and to fix both ends of the knife 31. The pair of pressing portions 51 rotate together with the shaft 50 rotating in conjunction with the coupling piece 52, and move the cutting edge 31a side of the fixed knife 31 so as to press the rear BA side downward.

Therefore, the shaft 50, the coupling piece 52, and the pair of pressing portions 51 function as a pressing force releasing mechanism 54 that moves the fixed blade 31 in a direction away from the movable blade 41 in accordance with the operation of the operating lever 46 (operation of the operating lever from a lock position P3 to a lock release position described later) to release the contact pressure between the fixed blade 31 and the movable blade 41.

As shown in fig. 6, a lock shaft 55 extending in the left-right direction L3 is attached to the support wall 34 of the platen unit 6. The lock shaft 55 is disposed behind the platen roller 30 at the BA, and is disposed parallel to the platen roller 30.

Next, the head unit 5 will be described in detail. As shown in fig. 7 to 10, the head unit 5 includes, in addition to the thermal head 40 and the movable blade 41, a movable blade driving mechanism 45, an operation lever 46, a release mechanism 47, an impression driving mechanism 48, and a return mechanism 49. These respective constituent members are supported by the head frame 42.

The head frame 42 has a pair of side wall portions 60, 61 located on the outer side in the left-right direction L3 than the support wall 34 of the platen frame 32. Further, as shown in fig. 7 and 8, the head frame 42 has a guide table 62 that guides the recording paper P. The guide table 62 is disposed inside the pair of side walls 60 and 61 in a state of facing forward FW and facing downward, and is formed to be inclined or curved so as to smoothly draw in the recording paper P.

Further, in a portion of the pair of side wall portions 60 and 61 located in front FW of the guide table 62, a fitting hole 63 into which the bearing 30b of the platen roller 30 is fitted is formed so as to open toward the front FW. When the printer cover 3 is closed, the platen unit 6 and the head unit 5 can be combined by fitting the bearing 30b of the platen roller 30 into the fitting hole 63.

Further, the pair of side walls 60 and 61 are formed with locking grooves 64 that open downward. The lock groove 64 is configured to engage and lock the lock shaft 55 of the platen unit 6 when the platen unit 6 and the head unit 5 are combined (see fig. 10). Thus, the platen unit 6 and the head unit 5 cannot be separated from each other unless the lock shaft 55 is disengaged from the lock groove 64 and the lock is released.

As shown in fig. 7 and 8, the thermal head 40 has a plurality of heat generating elements 40a arranged in a row along the left-right direction L3, and is attached to the head frame 42 so as to face the platen roller 30 when the printer cover 3 is in the closed state. Specifically, the thermal head 40 is attached to the head frame 42 so as to be positioned above the guide table 62 and in front FW. Further, the recording paper P can pass between the platen roller 30 and the thermal head 40. Further, a coil spring 65 that biases the thermal head 40 toward the platen roller 30 side is provided between the thermal head 40 and the head frame 42. This enables the thermal head 40 to be appropriately pressed against the recording paper P fed by the platen roller 30, and good printing by the printing unit 4 is possible.

As shown in fig. 8, the movable blade 41 is movable relative to the fixed blade 31, and is disposed above the fixed blade 31 so as to face the fixed blade 31 when the printer cover 3 is closed (see fig. 1) and the head unit 5 and the platen unit 6 are combined. The movable blade 41 is a plate-shaped blade extending in the width direction of the recording paper P (i.e., the left-right direction L3), and is formed in a substantially V-shape in plan view such that the length from the base to the cutting edge 41a gradually decreases from both ends in the left-right direction L3 toward the center.

Thus, when the recording sheet P slides toward the fixed blade 31, the movable blade 41 is pressed from the front FW side with respect to the fixed blade 31 as shown in fig. 11, and the recording sheet P can be sandwiched between the fixed blade 31 and cut. Further, as described above, since the fixed knife 31 is biased toward the front FW by the coil spring 65, the fixed knife 31 and the movable knife 41 can be brought into contact with each other with an appropriate contact pressure.

As shown in fig. 8, the movable knife 41 configured as described above is reciprocated by the movable knife drive mechanism 45 between a standby position P1 spaced apart from the fixed knife 31 and a cutting position P2 (see fig. 11 and 12) pressed against the fixed knife 31. The standby position P1 is a position at which the movable knife 41 stands by when printing is performed on the recording paper P, and is referred to as a so-called home position. The cutting position P2 is a position at which the movable blade 41 cuts the recording paper P in cooperation with the fixed blade 31.

As shown in fig. 8 and 9, the movable blade drive mechanism 45 mainly includes: a driving rack 70 attached to the movable blade 41; and a 1 st rack gear (rack gear according to the present invention) 71 and a 2 nd rack gear (rack gear according to the present invention) 72 that mesh with the drive rack 70 and rotate in accordance with the rotation of a cutter motor (drive motor according to the present invention) 73.

As shown in fig. 9, the cutter motor 73 is disposed on the inner surface side of one side wall portion 60 of the head frame 42, and is a motor that rotates forward and backward. As shown in fig. 8 and 9, on the outer surface side of the one side wall portion 60, a drive gear 74 coupled to a drive shaft of a cutter-use motor 73 is arranged. In the illustrated example, the drive gear 74 is partially protected by a circular arc-shaped protective cover 75.

The 1 st rack gear 71 is disposed on the outer surface side of the one side wall portion 60 and is disposed behind the drive rack 70 in a state of meshing with the drive rack 70. The 1 st rack gear 71 is disposed in front FW of the drive gear 74.

Further, an intermediate gear 76 is provided on the outer surface side of the one side wall portion 60, and the intermediate gear 76 is positioned between the drive gear 74 and the 1 st rack gear 71 and meshes with the drive gear 74 and the 1 st rack gear 71, respectively. The intermediate gear 76 is a 2-stage gear having a 1 st intermediate gear 77 having a large diameter meshing with the drive gear 74 and a 2 nd intermediate gear 78 having a small diameter meshing with the 1 st rack gear 71. Thereby, the rotation torque of the drive gear 74 can be transmitted to the 1 st rack gear 71 via the intermediate gear 76, and the 1 st rack gear 71 can be rotated in accordance with the rotation of the cutter motor 73. Then, the driving rack 70 can be linearly moved in the vertical direction L1 by rotating the 1 st rack gear 71. Further, the drive gear 74 and the intermediate gear 76 constitute the movable blade drive mechanism 45.

The 1 st rack is coupled to the coupling shaft 79 with the gear 71, and the coupling shaft 79 extends in the left-right direction L3 up to the other side wall portion 61 in the head unit 5. As shown in fig. 10 and 12, the 2 nd rack gear 72 is disposed behind BA of the drive rack 70 on the outer surface side of the other side wall portion 61 in the head frame 42 in a state of being coupled to the coupling shaft 79 and meshing with the drive rack 70. Thereby, the 2 nd rack gear 72 can be rotated in synchronization with the rotation of the 1 st rack gear 71, and the drive rack 70 can be linearly moved in the vertical direction L1.

As shown in fig. 8, the driving racks 70 are attached to both ends in the left-right direction L3 of the support plate 80 fixed to the root side of the movable blade 41. Thus, the pair of drive racks 70 can be simultaneously moved in the same direction by synchronously rotating the 1 st rack gear 71 and the 2 nd rack gear 72. As a result, the movable knife 41 can be slid in the vertical direction L1, and the movable knife 41 can be reciprocated between the standby position P1 and the cutting position P2.

As shown in fig. 9, the idler gear 76 of the present embodiment is formed with a toothed portion over a part of the range of the 1 st idler gear 77 in the circumferential direction, instead of forming a toothed portion over the entire circumference of the 1 st idler gear 77. Specifically, the 1 st intermediate wheel 77 is formed with a tooth portion in the amount of the rotation range in which the movable knife 41 reciprocates between the standby position P1 and the cutting position P2. Therefore, for example, when the drive gear 74 rotates with the driving of the cutter motor 73 and the movable blade 41 moves from the standby position P1 to the cutting position P2, the 1 st intermediate wheel 77 and the drive gear 74 can be prevented from further meshing with each other. This can restrict the 1 st intermediate wheel 77 from further rotation. Therefore, the rotation amount of the 1 st intermediate wheel 77 can be limited, and excessive movement of the movable blade 41 beyond the cutting position P2 can be suppressed.

As shown in fig. 8 and 9, a swing plate 81 formed in a C-shape in a side view as viewed from the left-right direction L3 is disposed between one side wall portion 60 of the head frame 42 and the 1 st rack gear 71 and the intermediate gear 76. As shown in fig. 13, the swing plate 81 is formed with an insertion through hole 82 through which the coupling shaft 79 that couples the 1 st rack gear 71 and the 2 nd rack gear 72 is inserted. Thereby, the swing plate 81 can swing along the wall surface of the one side wall portion 60 about the coupling shaft 79.

As shown in fig. 9, 14, and 15, the intermediate gear 76 is rotatably supported by an intermediate shaft 83 fixed to the swinging plate 81. Thereby, the intermediate gear 76 can swing in the front-rear direction L2 about the coupling shaft 79 as the swing plate 81 swings. Specifically, the swing plate 81 swings so that the intermediate gear 76 is maintained in a state of meshing with the 1 st rack gear 71, and swings between a position (see fig. 18) of separating from the drive gear 74 and releasing the meshing state with respect to the drive gear 74 and a position (see fig. 9) of approaching the drive gear 74 and maintaining the meshing state with respect to the drive gear 74.

A protruding pin 84 protruding outward in the left-right direction L3 is formed at an end of a portion of the swing plate 81 that extends rearward BA than the coupling shaft 79. The projecting pin 84 is continuously biased downward by a release lever 100 and a torsion coil spring 110, which will be described later. Therefore, at normal times, as shown in fig. 9, the swing plate 81 is biased so that the intermediate gear 76 approaches the drive gear 74, and the intermediate gear 76 and the drive gear 74 are always in a meshed state. As described above, the movable blade 41 can be moved between the standby position P1 and the cutting position P2 by the movable blade driving mechanism 45 by driving the cutter motor 73.

In addition, in accordance with the operation of the operating lever 46 (the operation from the lock position P3 to the lock release position), the projecting pin 84 is pushed up by a push-up piece 104 described later, and the swinging plate 81 swings against the elastic restoring force (biasing force) of the torsion coil spring 110. This allows the intermediate gear 76 to be separated from the drive gear 74, and the engagement between the intermediate gear 76 and the drive gear 74 to be released (see fig. 18).

As shown in fig. 8 and 9, the operating lever 46 is disposed below the swing plate 81 on the outer side of one side wall portion 60 in the head frame 42, and is rotatably supported via a lever support shaft, not shown. Thus, the operation lever 46 can be pushed in from the lock position P3 toward the unlock position toward the rear BA about the lever support shaft. Further, a lever support shaft is provided projecting from the inner surface of the gear cover 44 shown in fig. 7 toward the one side wall portion 60 side.

The lock position P3 is a position at which the platen unit 6 is maintained in a locked state with respect to the head unit 5. The lock release position is a position at which the locked state of the platen unit 6 with respect to the head unit 5 is released. Further, in the process of the operating lever 46 transitioning from the lock position P3 to the unlock position, the swing plate 81 is swung by the push-up piece 104, and the engagement of the intermediate gear 76 with the drive gear 74 is released.

As shown in fig. 13, 16, and 18, an annular lever plate 90 protruding toward the inner surface side is formed at the base end portion of the operation lever 46. A 2 nd engagement projection 91 projecting forward FW is formed on a part of the outer peripheral surface of the lever plate 90. Further, internal teeth 92 are formed in a portion of the outer peripheral surface of the lever plate 90 on the rear BA side.

As shown in fig. 9, the 2 nd engagement projection 91 is configured to come into contact with and engage with the 1 st engagement projection 53 formed on the platen unit 6 side from above when the platen unit 6 and the head unit 5 are combined. As a result, as shown in fig. 18, the operation lever 46 is pushed in from the lock position P3 toward the unlock position to the rear BA, and the coupling piece 52 can be pushed downward via the 1 st engagement projection 53. As a result, the pressure release mechanism 54 of the platen unit 6 can be operated in accordance with the operation of the operating lever 46, and the contact pressure between the fixed blade 31 and the movable blade 41 can be released by moving the fixed blade 31 in the direction away from the movable blade 41.

As shown in fig. 8 and 9, the release mechanism 47 is a mechanism for disconnecting the mechanical coupling between the 1 st rack gear 71 and the 2 nd rack gear 72 and the cutter motor 73 in accordance with the operation of the operating lever 46 from the lock position P3 to the unlock position, and includes the above-described swing plate 81 and the release lever 100.

As shown in fig. 9, 13, and 17, the release lever 100 is disposed between the operating lever 46 and the drive gear 74, and is disposed on the outer surface side of one side wall portion 60 in the head frame 42, being coupled to a rotary shaft 101 extending in the left-right direction L3. Thereby, the release lever 100 can rotate about the rotation axis of the rotation shaft 101. The release lever 100 is formed with release teeth 102 that mesh with the internal teeth 92 of the operating lever 46. When the operation lever 46 is pushed in from the lock position P3 toward the unlock position rearward BA, the release teeth 102 engage with the internal teeth 92 to rotate the release lever 100 upward.

As shown in fig. 8 and 9, a locking groove 103 to which one end 111 of the torsion coil spring 110 is locked is formed at an upper end edge of the release lever 100. The torsion coil spring 110 is disposed behind the drive gear 74 at BA and is fixed to a fixing pin 113 formed on one side wall portion 60. The other end 112 of the torsion coil spring 110 is locked to the head frame 42, and the release lever 100 is biased downward via the one end 111 by an elastic restoring force.

Further, as shown in fig. 9 and 13, the release lever 100 includes a push-up piece 104 that contacts or approaches from below with respect to the protruding pin 84 of the swing plate 81, and a lock release piece 105 that extends downward and rearward BA. The push-up piece 104 and the lock release piece 105 are disposed closer to the one side wall portion 60 of the head frame 42 than the operation lever 46.

The release lever 100 is biased downward by the torsion coil spring 110, and therefore, in a normal state, the push-up piece 104 does not push up the protruding pin 84 but contacts or approaches from below. Then, by rotating the release lever 100 upward against the biasing force of the torsion coil spring 110, the projecting pin 84 can be pushed up by the push-up piece 104, and the swing plate 81 can be swung. As a result, as shown in fig. 18, the intermediate gear 76 is separated from the drive gear 74, and the meshing state between the two is released, so that the intermediate gear 76, the 1 st rack gear 71, the 2 nd rack gear 72, and the drive rack 70 can be set in a free state. That is, the mechanical coupling between the 1 st rack gear 71 and the 2 nd rack gear 72 and the cutter motor 73 can be disconnected by pushing the operating lever 46 from the lock position P3 to the rear BA toward the unlock position.

Further, the release lever 100 is rotated by pushing the operating lever 46 from the lock position P3 to the rear BA toward the release position, and the release tab 105 can be rotated toward the front FW. At this time, the lock release piece 105 functions to press the lock shaft 55 fitted in the lock groove 64 from above and to disengage the lock shaft 55 from the lock groove 64. Fig. 18 is a diagram showing a state immediately before the operating lever 46 reaches the lock release position. Therefore, the operation lever 46 and the release lever 100 of the present embodiment also function as a unit release mechanism 106 that releases the combination of the head unit 5 and the platen roller 30 by disengaging the lock shaft 55 from the lock groove 64.

As shown in fig. 10 and 12, the platen drive mechanism 48 is provided to the other side wall portion 61 in the head frame 42. The platen drive mechanism 48 includes a platen gear train 120, and when the head unit 5 and the platen unit 6 are combined, the platen gear train 120 meshes with the driven gear 35 on the platen unit 6 side.

The gear train 120 for platen includes: a platen drive gear 122 coupled to a drive shaft of the platen motor 121; a 1 st platen intermediate gear 123 that meshes with the platen drive gear 122; a 2 nd impression intermediate gear 124 which meshes with the 1 st impression intermediate gear 123; and a 3 rd impression intermediate gear 125 which meshes with the 2 nd impression intermediate gear 124 and the driven gear 35. The platen motor 121 is disposed inside the other side wall portion 61. The 1 st, 2 nd and 3 rd impression intermediate gears 123, 124 and 125 are 2-stage gears.

Thus, when the head unit 5 and the platen unit 6 are combined, the rotational force of the platen motor 121 can be transmitted to the platen roller 30 via the platen gear train 120 and the driven gear 35, and the recording paper P can be fed by the platen roller 30.

As shown in fig. 10 and 12, the return mechanism 49 has a return gear 130 that meshes with the 2 nd rack gear 72, and is a mechanism that moves the movable blade 41 from the cutting position P2 to the standby position P1 when the release mechanism 47 disconnects the mechanical coupling between the 1 st rack gear 71 and the 2 nd rack gear 72 with the cutter motor 73.

The return gear 130 is disposed on the outer surface side of the other side wall portion 61 of the head frame 42 and above the 2 nd rack gear 72. The return gear 130 is rotatable around the rotation axis O1 in a state of meshing with the 2 nd rack gear 72. Therefore, the return gear 130 always rotates (rotates forward and backward) about the rotation axis O1 in accordance with the rotation of the 2 nd rack gear 72.

As shown in fig. 19 and 20, the return gear 130 is pivotally supported by a rotating shaft 140 formed in the other side wall portion (fixing member according to the present invention) 61 of the head frame 42. In fig. 19, the driving rack 70 is not shown. As shown in fig. 21 and 22, the return gear 130 includes: a top cylindrical gear body 131 having a tooth portion formed on an outer peripheral surface thereof to be engaged with the 2 nd rack gear 72; a flange portion 132 which is disposed on the side wall portion 61 side of the gear main body 131 and is formed larger in diameter than the gear main body 131; and a peripheral wall portion 133 which is disposed on the side of the side wall portion 61 with respect to the flange portion 132 and has the same diameter as the gear main body 131.

In a plan view viewed from the rotation axis O1 direction, a direction perpendicular to the rotation axis O1 is referred to as a radial direction, and a direction around the rotation axis O1 is referred to as a circumferential direction. A long slit hole (a locking hole according to the present invention) 134 is formed in a part of the return gear 130, and the slit hole 134 penetrates in the radial direction from the gear main body 131 to the flange portion 132 and the peripheral wall portion 133 and extends along the rotation axis O1. Further, the slit hole 134 is open toward the side wall portion 61 side. The slit hole 134 can lock a 1 st locking end 154 of the torsion coil spring 150, which will be described later, in a state of being inserted through the inside.

As shown in fig. 19 and 20, the return gear 130 configured as described above is axially supported by the rotating shaft 140 and meshes with the 2 nd rack gear 72 in a state of being accommodated in the accommodation recess 160 formed in the outer surface of the other side wall portion 61. The housing recess 160 is formed to be recessed stepwise in 3 steps and is disposed coaxially with the rotation axis O1. The housing recess 160 includes: an annular 1 st recessed portion 161 formed to be recessed from the other side wall portion 61 by one step; an annular 2 nd recess 162 which is disposed inside the 1 st recess 161 and is formed to be recessed further one step from the 1 st recess 161; and a 3 rd concave portion 163 disposed inside the 2 nd concave portion 162 and formed to be further recessed from the 2 nd concave portion 162 by one step.

The 2 nd recessed portion 162 is formed with a diameter larger than the diameter of the peripheral wall portion 133 of the return gear 130 and smaller than the diameter of the flange portion 132. The 1 st recess 161 is formed with a diameter larger than that of the flange portion 132 of the return gear 130. Thereby, the return gear 130 is housed in a state where the peripheral wall portion 133 enters the inside of the 3 rd concave portion 163 and the flange portion 132 is disposed inside the 1 st concave portion 161.

The rotation shaft 140 extends from the bottom of the 3 rd recess 163 outward in the left-right direction L3, and is disposed coaxially with the rotation axis O1. Thereby, as shown in fig. 23, the rotation shaft 140 is inserted into the return gear 130 to rotatably support the return gear 130. The return gear 130 is pivotally supported by the rotation shaft 140 with a gap from the 3 rd recess 163. As shown in fig. 20, a locking hole 164 extending outward in the radial direction is formed in a part of the 3 rd recess 163 and the 2 nd recess 162. The locking hole 164 can lock a 2 nd locking end portion 155 of the torsion coil spring 150, which will be described later.

As shown in fig. 20, a torsion coil spring (coil spring according to the present invention) 150 locked to each of the return gear 130 and the locking hole 164 is provided in the 3 rd recess 163. As shown in fig. 24, the torsion coil spring 150 includes: a coil portion 153 spirally wound around a coil axis O2 coaxial with the rotation axis O1 from the 1 st coil end 151 to the 2 nd coil end 152; a 1 st locking end portion 154 bent from the 1 st coil end 151 so as to extend outward in the radial direction; and a 2 nd locking end portion 155 bent from the 2 nd coiling end 152 so as to extend outward in the radial direction.

The coil portion 153 is formed by spirally winding a bare metal wire having a predetermined diameter and elastic modulus with a predetermined coil diameter and a predetermined number of turns. In the present embodiment, the torsion coil spring 150 is formed such that the coil diameter of the coil portion 153 is smaller than the diameter of the 3 rd recess 163. The 1 st and 2 nd latching end portions 154 and 155 are formed to extend straight outward in the radial direction from the 1 st and 2 nd coil ends 151 and 152. The lengths (arm lengths) of the 1 st locking end 154 and the 2 nd locking end 155 can be changed as appropriate.

Further, the torsion coil spring 150 of the present embodiment is formed such that the circumferential direction position of the 1 st locking end portion 154 along the circumferential direction of the coil portion 153 and the circumferential direction position of the 2 nd locking end portion 155 along the circumferential direction of the coil portion 153 are at the same position. That is, the 1 st locking end 154 and the 2 nd locking end 155 overlap each other when viewed from the coil axis O2 direction.

As shown in fig. 23, the torsion coil spring 150 configured as described above is housed in the 3 rd recessed portion 163 so as to surround the rotation shaft 140 from the outside in the radial direction. At this time, as shown in fig. 19, 20 and 22, the torsion coil spring 150 is attached in a state where the 1 st locking end portion 154 is locked to the return gear 130 and the 2 nd locking end portion 155 is locked to the side wall portion 61. Specifically, the 1 st locking end 154 is inserted into the slit hole 134 penetrating the return gear 130 from the inside toward the outside of the return gear 130, and the 1 st locking end 154 is locked in the circumferential direction with respect to the slit hole 134. At this time, a portion of the 1 st locking end 154 protruding to the outside of the return gear 130 is disposed inside the 1 st recess 161. The 2 nd locking end portion 155 is received inside the locking hole 164, and is locked to the locking hole 164 in the circumferential direction.

Thus, the return gear 130 is pivotally supported by the rotating shaft 140 via the torsion coil spring 150. Furthermore, the return gear 130 is assembled at the time of loading in the following manner: after the first locking end 154 of the torsion coil spring 150 is locked in the slit hole 134, the torsion coil spring is engaged with the 2 nd rack gear 72 in a state of being rotated by half a turn around the rotation axis O1. Thus, in a normal state, as shown in fig. 23, the torsion coil spring 150 is elastically deformed so as to be wound, and the 1 st locking end 154 and the 2 nd locking end 155 are located on opposite sides in the radial direction.

Due to the above-described configuration, when the 2 nd rack gear 72 rotates and the movable knife 41 slides from the standby position P1 toward the cutting position P2, the torsion coil spring 150 elastically deforms so as to be wound. Thus. The torsion coil spring 150 rotationally biases the 2 nd rack gear 72 via the return gear 130 by the elastic restoring force all the time so as to rotate the 2 nd rack gear 72 in the reverse direction. However, in a normal state, the 2 nd rack gear 72 is coupled to the drive gear 74 via the 1 st rack gear 71, the intermediate gear 76, and the like, and therefore does not rotate reversely by the elastic restoring force of the torsion coil spring 150.

However, when the movement restriction of the drive rack 70 is released by the release mechanism 47 and the 2 nd rack gear 72 is in the free state, the return gear 130 and the 2 nd rack gear 72 can be rotated in the reverse direction by the elastic restoring force of the torsion coil spring 150. This enables the 2 nd rack gear 72 and the 1 st rack gear 71 to rotate in opposite directions, and the movable knife 41 can be automatically returned from the cutting position P2 to the home standby position P1.

In addition, during normal operation, the return gear 130 rotates forward and backward along with the rotation of the 2 nd rack gear 72 every time the movable blade 41 moves between the standby position P1 and the cutting position P2. Accordingly, the torsion coil spring 150 is repeatedly elastically deformed in a winding and unwinding manner in accordance with the forward and reverse rotation of the return gear 130.

Next, a case of using the thermal printer 1 configured as described above will be described. According to the thermal printer 1 of the present embodiment, as shown in fig. 1 and 2, the printer cover 3 and the discharge port 18 are disposed on the front surface 13 side of the housing 2, and thus, for example, a usage in which the discharge port 18 is disposed at a doorway in a state of facing the store clerk side of the store can be performed. Therefore, the printed recording paper P can be delivered to the clerk side, and the printer can be used with good usability and excellent operability.

Specifically, when printing is performed on the recording paper P, the platen motor 121 shown in fig. 10 is driven to rotate the driven gear 35 via the platen gear train 120. This enables the platen roller 30 to rotate, and the recording paper P sandwiched between the thermal head 40 to be fed toward the discharge port 18. At the same time, a control signal corresponding to the print data is output to the thermal head 40, and the heating element 40a is appropriately heated. This allows various characters, graphics, and the like to be printed clearly on the fed recording paper P. The printed recording paper P passes between the fixed blade 31 and the movable blade 41.

Next, a case where printing is completed and the recording paper P is cut will be briefly described. In this case, the cutter motor 73 shown in fig. 9 is driven to rotate the drive gear 74. Thereby, the 1 st rack gear 71 can be rotated via the intermediate gear 76, and the 2 nd rack gear 72 can be rotated via the coupling shaft 79. Therefore, the driving rack 70 engaged with the 1 st rack gear 71 and the 2 nd rack gear 72 can be linearly moved, and the movable blade 41 can be moved from the standby position P1 shown in fig. 10 to the cutting position P2 shown in fig. 12.

By moving the movable blade 41 to the cutting position P2, as shown in fig. 11, the movable blade 41 can be pressed against the fixed blade 31, and the recording paper P can be sandwiched and cut by the cutting edges 31a and 41 a. As a result, the cut recording paper P can be used as a receipt, ticket, or the like, for example. Further, as shown in fig. 9, the tooth portion of the 1 st intermediate wheel 77 in the intermediate gear 76 is formed only within a certain range in the circumferential direction, and therefore, when the movable knife 41 is located at the cutting position P2, the tooth portion of the 1 st intermediate wheel 77 and the drive gear 74 are not further meshed. Therefore, the movable blade 41 can be prevented from moving excessively beyond the cutting position P2.

After the recording paper P is cut, the cutter motor 73 is rotated in the reverse direction. Thereby, the 1 st rack gear 71 and the 2 nd rack gear 72 can be rotated in reverse via the drive gear 74 and the intermediate gear 76. Therefore, the movable knife 41 can be returned from the cutting position P2 to the standby position P1 (home position) via the driving rack 70, and the next cutting can be prepared.

Next, the following recovery will be explained: in use, a jam or the like of the recording paper P occurs, and thus the fixed blade 31 and the movable blade 41 bite into each other and fall into a cutter lock state. When the cutter is stuck in the cutter lock state, the movable knife 41 stops at the cutting position P2 pressed against the fixed knife 31 as shown in fig. 11.

In this case, as shown in fig. 1, the lock release lever 20 disposed on the front surface 13 side of the housing 2 is depressed. As a result, the operation lever 46 shown in fig. 9 can be pushed in from the lock position P3 toward the unlock position toward the rear BA in conjunction with the operation of the unlock lever 20.

By operating the operating lever 46 from the lock position P3 to the unlock position, the 2 nd engagement projection 91 formed on the operating lever 46 can be moved downward. Therefore, as shown in fig. 18, the pressure release mechanism 54 on the platen unit 6 side can be operated to release the contact pressure between the fixed blade 31 and the movable blade 41. Specifically, by moving the 2 nd engagement projection 91 downward, the 1 st engagement projection 53 on the platen unit 6 side can be pressed downward, and the coupling piece 52 and the shaft 50 can be rotated. Therefore, it is possible to rotate the push-down part 51 coupled to the shaft 50 and push down the cutting edge 31a side of the fixed knife 31 toward the rear BA side. This can forcibly move the fixed blade 31 in the direction away from the movable blade 41, and can release the contact pressure between the fixed blade 31 and the movable blade 41, which causes the bite.

Further, by operating the operating lever 46 from the lock position P3 toward the unlock position, in addition to the operation of the pressure release mechanism 54 described above, the release mechanism 47 can be used to disconnect the mechanical coupling between the 1 st and 2 nd rack gears 71, 72 and the cutter motor 73. Specifically, the release lever 100 can be rotated upward against the biasing force of the torsion coil spring 110 via the release teeth 102 that are meshed with the internal teeth 92 of the operating lever 46 by operating the operating lever 46. As a result, the projecting pin 84 of the swing plate 81 can be pushed upward by the push-up piece 104 formed on the release lever 100, and the swing plate 81 can be swung forward FW.

This allows the intermediate gear 76 attached to the swing plate 81 to be separated from the drive gear 74, and the meshing state between the intermediate gear 76 and the drive gear 74 can be released. Therefore, the intermediate gear 76, the 1 st rack gear 71, the 2 nd rack gear 72, and the drive rack 70 can be set in a free state. As a result, the 1 st rack gear 71 and the 2 nd rack gear 72 can be mechanically decoupled from the cutter motor 73.

As described above, the release mechanism 47 disconnects the mechanical coupling between the 1 st and 2 nd rack gears 71, 72 and the cutter motor 73, and the 1 st and 2 nd rack gears 71, 72 and the drive rack 70 can be transitioned to a free state in which the coupling with the cutter motor 73 is lost. As a result, the return mechanism 49 shown in fig. 12 can forcibly rotate the 1 st rack gear 71 and the 2 nd rack gear 72 in the reverse direction via the return gear 130, and automatically return the movable knife 41 from the cutting position P2 to the standby position P1, which is the home position.

As described above, by operating the operating lever 46 from the lock position P3 to the unlock position, the contact pressure between the fixed blade 31 and the movable blade 41 can be released, and the movable blade 41 can be quickly returned from the cutting position P2 to the standby position P1.

Further, in the present embodiment, the lock shaft 55 can be disengaged from the inside of the lock groove 64 by the unit release mechanism 106 in the process of operating the operating lever 46 from the lock position P3 toward the unlock position. Specifically, by operating the operating lever 46, as shown in fig. 18, the lock release piece 105 formed on the release lever 100 can be rotated toward the front FW. Thus, the lock shaft 55 of the platen unit 6 can be pressed from above by the lock releasing piece 105, and the lock shaft 55 can be disengaged from the lock groove 64 formed in the head frame 42. This enables the head unit 5 and the platen roller 30 to be released from combination.

Therefore, the printer cover 3 can be opened, and the platen unit 6 can be largely separated from the head unit 5 in association with the opening operation. This enables appropriate measures such as removal of a jammed portion of the recording paper P, and the cutter lock state can be restored.

As described above, according to the thermal printer 1 of the present embodiment, the contact pressure between the fixed knife 31 and the movable knife 41 can be released by a simple method of operating the operating lever 46, and the movable knife 41 can be automatically returned to the original standby position P1 and the lock shaft 55 can be disengaged from the lock groove 64. Therefore, even if the cutter lock state occurs, the recovery operation can be easily and appropriately performed, and the thermal printer 1 with improved convenience can be obtained.

In particular, in the thermal printer 1 of the present embodiment, the return gear 130 is rotated in the reverse direction by the elastic restoring force of the torsion coil spring 150, and the 1 st rack gear 71 and the 2 nd rack gear 72 can be forcibly rotated in the reverse direction. Specifically, as shown in fig. 19 and 23, the torsion coil spring 150 is attached in a state in which the 1 st locking end 154 is locked to the slit hole 134 of the return gear 130 and the 2 nd locking end 155 is locked to the locking hole 164 formed in the head frame 42. Therefore, in the process of moving the movable knife 41 from the standby position P1 to the cutting position P2, the return gear 130 rotates along with the rotation of the 2 nd rack gear 72, and the torsion coil spring 150 can be elastically deformed so as to be wound as shown in fig. 25 and 26.

Fig. 25 is a diagram showing a state of the torsion coil spring 150 on the way of the movable blade 41 moving from the standby position P1 to the cutting position P2. Fig. 26 is a diagram showing a state of the torsion coil spring 150 in which the movable blade 41 reaches the cutting position P2, is elastically deformed to be wound to the maximum extent, and accumulates an elastic restoring force.

Accordingly, when the 1 st rack gear 71 and the 2 nd rack gear 72 are shifted to the free state by the release mechanism 47, the return gear 130 can be rotated in the reverse direction by the elastic restoring force based on the elastic restoring deformation of the torsion coil spring 150. As a result, the movable knife 41 can be quickly returned to the standby position P1.

However, since the return gear 130 is meshed with the 2 nd rack gear 72, the movable knife 41 rotates forward and backward every time it moves between the standby position P1 and the cutting position P2 during the normal operation. Accordingly, the torsion coil spring 150 is repeatedly elastically deformed in a winding and unwinding manner in accordance with the forward and reverse rotation of the return gear 130. At this time, with respect to the torsion coil spring 150, both the 1 st latching end portion 154 and the 2 nd latching end portion 155 are bent from the winding ends (the 1 st winding end 151 and the 2 nd winding end 152) of the coil portion 153 so as to extend outward in the radial direction of the coil portion 153. Therefore, the rotational torque transmitted from the return gear 130 to the torsion coil spring 150 can be transmitted to the base end portion (the connection portion between the 1 st locking end portion 154 and the 1 st winding end 151) side of the 1 st locking end portion 154 as indicated by an arrow F shown in fig. 25 and 26.

Here, as shown in fig. 27 and 28, when the conventional torsion coil spring 170 in which the 1 st locking end portion 171 extends along the coil axis O2 is used, the return gear 130 rotates, and the rotational torque is transmitted to the topmost end portion side of the 1 st locking end portion 171 as shown by an arrow F in fig. 29. Therefore, since the portion to which the rotational torque is transmitted is located at a position spaced apart from the coil portion 172 in the coil axis O2 direction, the torsion coil spring 170 is likely to be largely inclined, and is elastically deformed in a state where the coil axis O2 is inclined with respect to the rotation axis O1. Therefore, the torsion coil spring 170 having the 1 st locking end portion 171 extending along the coil axis O2 is not only lacking in stability, but also is susceptible to unintended repetitive stress (pressure).

In contrast, as shown in fig. 23, 25, and 26, in the case of the torsion coil spring 150 of the present embodiment, the point at which the rotational torque is transmitted from the return gear 130 can be shifted toward the coil portion 153 side compared to the case of using the torsion coil spring 170, and the vicinity of the connection portion between the 1 st locking end portion 154 and the 1 st winding end portion 151 can be obtained. This allows the torsion coil spring 150 to be elastically deformed while suppressing the inclination of the coil axis O2 with respect to the rotation axis O1, and thus to be less likely to receive unintended repetitive stress (pressure). Therefore, the torsion coil spring 150 can be stably operated over a long period of time, and the predetermined operation requirement number can be sufficiently satisfied. Therefore, even if the cutter locked state occurs, the movable blade 41 can be appropriately returned to the standby position P1 by the elastic restoring force of the torsion coil spring 150, and the cutter locked state can be appropriately and quickly released.

Further, not only is the torsion coil spring 150 disposed so as to surround the rotation shaft 140 from the outside in the radial direction, but also the return gear 130 is pivotally supported by the rotation shaft 140, so that the posture of the torsion coil spring 150 is further easily stabilized, and the return gear 130 can be stably rotated in the reverse direction. Further, it becomes easy to smoothly assemble the torsion coil spring 150 and the return gear 130 by the rotation shaft 140. Further, in a state where the 1 st locking end 154 is stably locked by the slit hole 134, the torsion coil spring 150 can be combined with the return gear 130, and thus the above-described operational effects can be appropriately exerted, and the cutter lock state can be appropriately released.

The embodiments of the present invention have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. The embodiments may be implemented in various other ways, and various omissions, substitutions, and changes may be made without departing from the spirit of the invention. Examples, substantially the same examples, examples of equivalent ranges, and the like, which can be easily conceived by those skilled in the art, are included in the embodiments or the modifications thereof.

For example, in the above-described embodiment, the thermal printer 1 is described as an example of the printer, but the present invention is not limited to the thermal printer 1. For example, the present invention can be applied to printers other than the thermal printer 1, such as an ink jet printer that prints on the recording paper P with ink droplets. In this case, a cutter-equipped printing unit having an inkjet head instead of the thermal head 40 may be used.

Further, in the above-described embodiment, the description has been given of the configuration in which the head unit 5 is provided on the side of the housing 2 and the platen unit 6 is provided on the side of the printer cover 3, but the present invention is not limited to this configuration, and for example, the head unit 5 may be provided on the side of the printer cover 3 and the platen unit 6 may be provided on the side of the housing 2.

Further, in the above embodiment, the 1 st locking end portion 154 and the 2 nd locking end portion 155 of the torsion coil spring 150 are formed to extend straight outward in the radial direction from the 1 st coil end 151 and the 2 nd coil end 152, but the present invention is not limited to this case. For example, the 1 st locking end 154 and the 2 nd locking end 155 may be bent halfway by 1 step or bent stepwise, or may be bent in a hook shape.

Further, in the above embodiment, the torsion coil spring 150 is formed such that the circumferential direction position of the 1 st locking end portion 154 along the circumferential direction of the coil portion 153 and the circumferential direction position of the 2 nd locking end portion 155 along the circumferential direction of the coil portion 153 are the same position, but is not limited to this case. Further, when the torsion coil spring 150 is formed such that the circumferential direction position of the 1 st locking end portion 154 and the circumferential direction position of the 2 nd locking end portion 155 are the same, there is an advantage that the torsion coil spring 150 and the like can be easily manufactured, for example.

In the torsion coil spring according to the present invention, both the 1 st locking end and the 2 nd locking end may extend in the radial direction of the coil portion, and the circumferential direction position of the 1 st locking end and the circumferential direction position of the 2 nd locking end may be different positions. Even in this case, the same effects can be obtained. For example, as shown in fig. 30, the torsion coil spring 150 may be formed such that the circumferential direction position of the 1 st locking end 154 and the circumferential direction position of the 2 nd locking end 155 are spaced apart by 90 degrees around the coil axis O2. Further, as shown in fig. 31, the torsion coil spring 150 may be formed such that the circumferential direction position of the 1 st locking end portion 154 and the circumferential direction position of the 2 nd locking end portion 155 are spaced apart by 180 degrees around the coil axis O2.

Thus, the circumferential direction position of the 1 st locking end 154 and the circumferential direction position of the 2 nd locking end 155 can be changed as appropriate. In the case of the torsion coil spring 150 having different circumferential positions of the 1 st locking end 154 and the 2 nd locking end 155, for example, the torsion coil spring can be suitably used in a case where the circumferential position of the return gear 130 is set to a predetermined position at the time of assembling the return gear 130.

Claims (7)

1. A printing unit with a cutter is characterized by comprising:

a movable blade driving mechanism having a driving rack coupled to a movable blade that cuts a recording sheet in cooperation with a fixed blade and a rack gear that meshes with the driving rack and rotates in accordance with rotation of a driving motor, the movable blade moving between a standby position spaced apart from the fixed blade and a cutting position pressed against the fixed blade; and

a return mechanism having a return gear that meshes with the rack gear, the return mechanism moving the movable knife from the cutting position to the standby position when the mechanical coupling between the rack gear and the drive motor is disconnected,

the return mechanism includes a coil spring having a coil portion spirally wound around a coil axis from a 1 st coil end to a 2 nd coil end, a 1 st locking end portion bent from the 1 st coil end so as to extend outward in a radial direction of the coil portion, and a 2 nd locking end portion bent from the 2 nd coil end so as to extend outward in the radial direction of the coil portion,

the coil spring is attached in a state where the 1 st locking end is locked to the return gear and the 2 nd locking end is locked to a fixing member.

2. The printing unit with cutter according to claim 1,

the return mechanism has a rotating shaft portion disposed coaxially with the coil axis and pivotally supporting the return gear,

the coil spring is arranged to surround the rotating shaft portion from a radial direction outer side,

the return gear is formed with a locking hole which penetrates the return gear in a radial direction and locks the 1 st locking end in a state of being inserted through the inside.

3. The printing unit with cutter according to claim 1,

the coil spring is formed such that a circumferential direction position of the 1 st latching end portion in a circumferential direction of the coil portion and a circumferential direction position of the 2 nd latching end portion in the circumferential direction become the same position.

4. The printing unit with cutter according to claim 1,

the coil spring is formed such that a circumferential direction position of the 1 st latching end portion in a circumferential direction of the coil portion and a circumferential direction position of the 2 nd latching end portion in the circumferential direction become different positions.

5. The printing unit with cutter according to claim 1, comprising:

a 1 st unit having the fixed knife;

a 2 nd unit having the movable blade and detachably combined with the 1 st unit;

an operation lever operable between a lock position to lock the 2 nd unit with respect to the 1 st unit and an unlock position to unlock the 2 nd unit with respect to the 1 st unit; and

a release mechanism that releases the mechanical coupling between the rack gear and the drive motor in response to an operation of the operating lever from the lock position to the unlock position,

one of the 1 st unit and the 2 nd unit has a platen roller, and the other unit has a thermal head.

6. The printing unit with cutter according to claim 5,

the pressing force releasing mechanism includes a pressing portion that moves the fixed blade in a direction away from the movable blade and releases the contact pressing force between the fixed blade and the movable blade in accordance with the operation of the operating lever from the lock position to the unlock position.

7. A printer is characterized by comprising:

the printing unit with cutter of claim 1;

a printer main body that accommodates the recording paper; and

a printer cover rotatably coupled with respect to the printer body.

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