JP3588900B2 - Ink ribbon device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink ribbon device of a small printer using a ribbon impregnated with ink.
[0002]
[Prior art]
Conventionally, as this kind of technique, a technique of detecting the rewind diameter of the ink ribbon and performing the reversing operation of the ribbon is known. There is a problem that waste occurs. As a countermeasure, a mechanism for detecting ribbon end tension and performing ribbon reversal has been used. FIGS. 14 to 17 show an actual example of Japanese Utility Model Application Laid-Open No. 63-170156, and its operation will be described.
[0003]
Reference numeral 101 denotes a ribbon base. On both sides of the ribbon base 101, a pair of left and right ratchets 102 and 103 whose blades are oriented symmetrically are rotatably held, and rotate integrally with the ratchets 102 and 103. A long ribbon 106 is wound around spools 104 and 105, which are circular bodies. These ratchets 102 and 103 have a braking member such as a coil spring pressed against the outer periphery of the shaft portion so as not to rotate due to inertia. A movable body 108 having a rack 107 is held on the ribbon base 101 so as to be linearly reciprocable between the ratchets 102 and 103. At the center of the movable body 108, a fulcrum shaft 123 having a sharp edge-shaped projection 126 and a hook 110 are integrally formed.
[0004]
The ribbon base 101 is provided with an oscillating body 113 having feed claws 111 and 112 at both ends. The oscillating body 113 has a projection 115 having a sharp edge at the center and projecting in a V-shape. A pair of left and right recesses 117 and 118 that are continuous with the slopes 116 on both sides of the protrusion 115 and a hook 119 located outside the recesses 117 and 118 are formed. The other ends of the springs 120 and 121 having one ends fixed to these hooks 119 are fixed to the hooks 110 of the movable body 108.
[0005]
Further, a gear 122 meshed with the rack 107 is rotatably held on the ribbon base 101. The gear 122 is meshed with a timing belt for reciprocating the carrier holding the print head in the left-right direction. As a result, the carrier rotates following the reciprocating motion of the carrier.
[0006]
As shown in FIGS. 14 and 15, in a state of being engaged with the concave portion 117 on the left side of the fulcrum shaft 123, the rocking body 113 is biased by the spring 121 and tilts upward to the right. In this state, when the gear 122 follows the reciprocating motion of the carrier and alternately rotates clockwise and counterclockwise, the movable body 108 reciprocates in the left and right direction together with the rocking body 113, and when moving to the right, The feed claw 112 of the rocking body 113 rotates the right ratchet 103 counterclockwise. As a result, the right spool 105 intermittently winds the ribbon 106 from the left spool 104.
[0007]
Then, when the right spool 105 finishes winding the ribbon 106, the ratchet 103 cannot rotate even if the rocking body 113 is operated because the both ends of the ribbon 106 are fixed to the spools 104 and 105. Resist the rightward movement of As a result, when the movable body 108 moves to the right, the rocking body 113 moves to the left with respect to the movable body 108, and the protrusion 115 of the rocker 113 climbs over the protrusion 126 of the fulcrum shaft 123 (FIG. 16). The recess 118 of the rocking body 113 and the fulcrum shaft 123 engage (FIG. 17).
[0008]
At this moment, the oscillating body 113 is inclined upward to the left as a fulcrum, and the left ratchet 102 is intermittently rotated clockwise by the left feeding claw 111 when the movable body 108 moves to the left. Thereby, the left spool 104 winds the ribbon 106 from the right spool 105.
[0009]
Thereafter, the reversing operation of the ribbon feeding direction is continuously performed by the tension of the ribbon end by repeating the operation.
[0010]
[Problems to be solved by the invention]
However, in the above-described prior art, the surface pressure immediately before the projecting portion of the oscillator has passed over the projecting portion of the support shaft is extremely large, so that a large driving force is required for ribbon switching. The tip of the projection and the projection of the support shaft must have a completely sharp edge in order to obtain an unstable contact state. And the protrusion of the support shaft, there is a region where the tip is in stable contact, there is a problem that there is a possibility of poor switching,
Durability wear occurs due to sliding between the projecting part of the oscillator and the projecting part of the support shaft, and the contact state of both parts gradually comes into contact with point contact from the point contact. Then, the contact state is maintained and the cost is reduced, and as the number of times of switching increases, a switching failure tends to occur.
[0011]
Further, there is a problem that the number of components such as a driving member, a feeding member, and a switching member for detecting the tension of the ribbon end and performing the switching operation of the ribbon feeding direction is increased, resulting in an increase in component costs and assembly costs. Was.
[0012]
The present invention has been made in order to solve such a disadvantage, and an object of the present invention is to prevent a surface pressure from being generated at the time of ribbon switching, to allow ribbon switching to be performed smoothly, and to provide a protrusion during switching. Wear is extremely small, and the mechanism which is not affected by wear improves the durability reliability. Even if the switching member stops during the ribbon feed switching, the ribbon feeding direction is surely performed in the next operation. It is possible to set the number of parts such as the driving member, the feed member, the switching member to the minimum necessary, improve the assemblability while being low cost, and use the ink ribbon efficiently to the end of the An object of the present invention is to provide a reliable ink ribbon device.
[0013]
[Means for Solving the Problems]
The ink ribbon device of the present invention includes:
(1) An ink ribbon device of a printer used by rewinding or winding a pair of ribbon spools on which an ink ribbon impregnated with ink is stretched and reciprocating the ink ribbon.
A pair of ribbon spools that are arranged at both ends of the ink ribbon, the winding start portion is fixed, and the ink ribbon is wound,
A ribbon frame which is a base member attached to the printer,
A pair of spool gears around which a ratchet is arranged and rotatably attached to the ribbon frame;
A ribbon feed plate which is externally driven and is movably disposed on the ribbon frame, and on which a cam portion having two predetermined positions is formed;
A ribbon feeding claw that includes a fulcrum that is movable to the two predetermined positions of the cam portion, engages the ratchet of the spool gear, and rotates the spool;
An urging member attached to the ribbon feeding plate at one end and the ribbon feeding plate at the other end, so as to urge the ribbon feeding claw toward the two predetermined positions;
A reverse stop pawl rotatably disposed on the ribbon frame and engaged with the ratchet of the spool gear to prevent the ribbon feed pawl from rotating in a direction opposite to the direction in which the spool gear rotates. And
When the fulcrum moves from one position to the other of the cam, the ribbon feed pawl changes the moment direction by the urging member, and changes the spool gear that is driven to rotate.
The ribbon frame engages with the ribbon feed pawl when the ribbon feed pawl tip does not engage with the ribbon spool gear, and holds the ribbon such that the ribbon feed pawl tip approaches one of the ribbon spool gears. A rotary slope for rotating the feed claw is provided.
According to this configuration, the ribbon that has been wound on the ribbon wheel on one of the spool gears is forcibly rotated by the ribbon feed claw to feed the ribbon in a certain direction, and the feed is completed. When the rotation of the ribbon feed pawl is stopped, when the ribbon feed plate moves while the ribbon feed pawl is stopped, the fulcrum of the ribbon feed pawl moves from one position of the cam to the other, and as a result, The direction of the moment is changed, the spool gear that is driven to rotate is changed, the spool on the side where the ribbon has been fed is rotated, the ribbon feeding direction is changed to the opposite direction, and the ribbon can be fed. Is not engaged with the ribbon spool gear, the ribbon feed claw is rotated by the rotation slope so as to approach the ribbon spool gear. Is in contact with the spur gear moments from the urging member is increased, switching failure is less likely to occur.
(2) In an ink ribbon device of a printer used by rewinding or winding a pair of ribbon spools on which an ink ribbon impregnated with ink is stretched and reciprocating the ink ribbon,
A pair of ribbon spools that are arranged at both ends of the ink ribbon, the winding start portion is fixed, and the ink ribbon is wound,
A ribbon frame which is a base member attached to the printer,
A pair of spool gears around which a ratchet is arranged and rotatably attached to the ribbon frame;
A ribbon feed plate which is externally driven and is movably disposed on the ribbon frame, and on which a cam portion having two predetermined positions is formed;
A ribbon feeding claw that includes a fulcrum that is movable to the two predetermined positions of the cam portion, engages the ratchet of the spool gear, and rotates the spool;
An urging member attached to the ribbon feeding plate at one end and the ribbon feeding plate at the other end, so as to urge the ribbon feeding claw toward the two predetermined positions;
A reverse stop pawl rotatably disposed on the ribbon frame and engaged with the ratchet of the spool gear to prevent the ribbon feed pawl from rotating in a direction opposite to the direction in which the spool gear rotates. And
When the fulcrum moves from one position to the other of the cam, the ribbon feed pawl changes the moment direction by the urging member, and changes the spool gear that is driven to rotate.
The amount of movement of the ribbon feed plate is the amount required for the fulcrum to move from one position of the cam of the ribbon feed plate to the other, and the amount that the ribbon feed pawl feeds the ratchet of the spool gear at least one tooth. Is set to the combined movement amount.
According to this configuration, the ribbon that has been wound on the ribbon wheel on one of the spool gears is forcibly rotated by the ribbon feed claw to feed the ribbon in a certain direction, and the feed is completed. When the rotation of the ribbon feed pawl is stopped, when the ribbon feed plate moves while the ribbon feed pawl is stopped, the fulcrum of the ribbon feed pawl moves from one position of the cam to the other, and as a result, The direction of the moment changes, the rotating spool gear is changed, the spool on the side where the ribbon has been fed is rotated, the ribbon feeding direction is changed to the opposite direction, and the ribbon feeding can be performed. The ribbon can be reliably locked at the reversible position, and no malfunction of the ribbon feeding claw occurs, and the reliability is further improved.
(3) The cam portion has a heart shape obtained by punching the ribbon feed plate.
According to this configuration, since the cam portion has a heart shape obtained by punching the ribbon feeding plate, the ribbon feeding claw can rotate to the side surface of the heart shape without applying a load by the cam portion. It can be formed smoothly and with improved reliability, and can be formed at low cost with a simple mechanism.
(4) The ribbon feeding claw is characterized in that a rotation inclined surface that engages with the reverse rotation prevention claw and rotates the spool gear that rotates the reverse rotation prevention claw is disposed.
According to this configuration, when the ribbon feeding claw is moved after being rotated, the reverse rotation preventing claw is rotated by the rotating slope, so that switching failure does not occur and reliability is greatly improved.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a mechanism of an ink ribbon device of a small printer according to an embodiment of the present invention. FIGS. 2 to 13 show explanatory views of a mechanism of the ink ribbon device and a ribbon feeding operation, and FIG. FIG. 3 shows a ribbon feeding start operation, and FIG. 3 shows a state during the ribbon feeding operation. FIG. 4 shows a state in which the movement of the ribbon feed plate in the forward direction is completed.
[0024]
FIG. 5 shows an operation at the start of the ink ribbon feed reversal operation when the ink ribbon ends. FIG. 6 is an explanatory view of the operation during the reversal, and shows a state where the center of the ribbon feed pawl fulcrum pin has passed the center of the heart cam. FIG. 7 is a diagram in which the reversing operation of the ribbon feed claw is completed on the opposite spool gear, and is an explanatory view of the reversal. FIG. 8 is a diagram in which the reversing stopper claw has completed the reversing operation on the opposite spool gear. FIG. FIGS. 9 to 13 are views for explaining the recovery operation of the ribbon feed pawl when the inverting operation of the ribbon feed pawl stops halfway and it is impossible to reach the position where the ribbon feed pawl engages with the ratchet of the spool gear.
[0025]
Reference numeral 3 denotes a ribbon feed plate, which is slidably driven in parallel in the direction of arrow a and the direction of arrow b opposite thereto by a cam of a gear (not shown) which is attached to the printer body frame and driven to rotate.
[0026]
A heart cam 3A is formed on the ribbon feed plate 3, and a ribbon feed pawl 5 for driving spool gears 2A and 2B for rotating a ribbon wheel (not shown) is rotatably attached to the heart cam 3A. The ribbon feed claw 5 is urged to face spool gears 2A and 2B driven by a feed claw spring 6 whose one end is locked to the ribbon feed plate 3, and the ribbon feed claw fulcrum pin 9 of the fulcrum portion is connected to the heart cam 3A. It is abutted in the upper direction.
[0027]
Reference numeral 4 denotes a reverse stop pawl formed with pawls 4A and 4B for engaging with the spool gears 2A and 2B, and rotatably attached to the ribbon frame 1 by a reverse stop pawl fulcrum pin 8. Numeral 7 denotes a reverse-stopping claw spring, which is a two-stable spring of a torsion coil spring having one end fixed to the tip of the reverse-stopping claw 4 and the other end locked to the ribbon frame 1. The reverse stop pawl 4 is urged by a reverse stop pawl spring 7 so that the pawl 4A or the pawl 4B is engaged with the spool gear 2A or 2B.
[0028]
Next, the operation will be described.
FIG. 2 shows the operation of starting the feeding of the ink ribbon when the ribbon feeding pawl fulcrum pin 9 is located on the right side of the heart cam 3A of the ribbon feeding plate 3. In this case, the claw 4A of the reverse rotation preventing claw 4 and the tip 5A of the ribbon feeding claw of the ribbon feeding claw 5 are engaged with the spool gear 2A. When the ribbon feed plate 3 is moved in the direction of arrow a, the ribbon feed pawl 5 moves in the direction of arrow a via the feed pawl spring 6, and the leading end 5A of the ribbon feed pawl engages with the ratchet of the spool gear 2A to rotate the spool. The gear 2A is rotated. The ribbon wheel mounted so as to rotate in synchronization with the spool gears 2A and 2B winds the ink ribbon by rotating the spool gear 2A counterclockwise, so that the ink ribbon between the two ribbon wheels is removed. The ribbon wheel is rotated in the counterclockwise direction together with the spool gear 2B, and the ink ribbon is rewound.
[0029]
FIG. 4 shows the limit of the movement range of the ribbon feed plate 3 in the direction of the arrow a, with the ribbon feed plate 3 further moving in the direction of the arrow a than in FIG. When the ink ribbon is wound, the ribbon feed plate 3 moves in the direction of arrow b, the pawl 4A of the reverse rotation preventing pawl 4 locks the ratchet of the spool gear 2A, and the ribbon feed plate 3 and the ribbon feed pawl 5 feed the ribbon. Return to the starting position. This completes the one-step ribbon feeding operation.
[0030]
The feed pawl spring 6 has two functions. One is to bring the ribbon feed pawl 5 into pressure contact with the ratchet of the spool gear 2A during normal ribbon feed, and the spool is moved when the ribbon feed plate 3 moves in the direction of arrow a. The second function is to rotate the gear 2A to transmit a driving force necessary for feeding a certain amount of ribbon, and the other is to reverse the ribbon feeding claw 5 from the spool gear 2A to the spool gear 2B during the reversing operation in the ribbon feeding direction. There is a function to make.
[0031]
Next, a reversing operation in which the driven spool gear 2A is converted into the spool gear 2B when the ink ribbon of the ribbon wheel attached to the spool gear 2B is rewound and no longer used will be described.
[0032]
FIG. 5 shows an operation in the middle of the ink ribbon feed reversal operation when the ink ribbon is wound in the opposite direction to reach the ink ribbon end. At the end of the ink ribbon, tension is generated in the ink ribbon, and the rotation of the spool gear 2A is forcibly stopped. Since the ribbon feed plate 3 continuously moves in the direction of arrow a, when the tension of the ink ribbon exceeds the spring force of the feed claw spring 6, the tip 5A of the ribbon feed claw is locked to the ratchet of the spool gear 2A. Then, the feed claw spring 6 starts to expand.
[0033]
The ribbon feed pawl fulcrum pin 9 engaged at the upper right side of the heart cam 3A is driven by the operating force of the feed pawl spring 6 to rotate the center of rotation of the locking portion between the ribbon feed pawl tip 5A and the ratchet of the spool gear 3A. It gradually moves along the upper slope of 3A to the central projection of the heart cam 3A.
[0034]
FIG. 6 shows an operation in the middle of the ribbon feed reversal operation in which the reversal operation is further advanced than in FIG. The shape of the heart cam 3A is formed so that the upper and lower portions of the cam 3A are larger than the rotation trajectory of the ribbon feed claw fulcrum pin 9 so that the ribbon feed claw fulcrum pin 9 can be rotated at a stroke on the left side wall of the heart cam 3A. Therefore, the ribbon feed pawl fulcrum pin 9 is guided by the operating force of the feed pawl spring 6 into the shape of the heart cam 3A of the ribbon feed plate 3A with the ratchet of the spool gear 2A and the locking point of the ribbon feed pawl tip 5A as a fulcrum. Turns to the left side wall at a stretch. Further, the ribbon feed plate 3 continues to move in the direction of arrow a while the ribbon feed pawl fulcrum pin 9 is rotated toward the left side wall of the heart cam 3A.
[0035]
FIG. 7 shows a state in which the movement of the ribbon feeding claw 5 is completed. After finishing moving in the direction of arrow a, the ribbon feed plate 3 moves in the direction of arrow b. While the ribbon feed plate 3 is moving in the direction of arrow b, the claw 4A of the reverse rotation preventing claw 4 locks the spool gear 2A, but the ribbon feed plate 3 and the ribbon feed claw 5 continue to move in the direction of arrow b. Then, the ratchet of the tip of the ribbon feed pawl 5A and the ratchet of the spool gear 2A are disengaged, and the ribbon feed pawl abutted in the upper direction on the left side of the heart cam 3A by the counterclockwise moment applied to the ribbon feed pawl 5 by the feed pawl spring 6. The ribbon feed claw 5 rotates counterclockwise about the fulcrum pin 9 as a rotation center, and the ribbon feed claw tip 5B instantaneously engages with the ratchet of the spool gear 2B.
The reverse stop pawl is being moved in the ratchet direction of the spool gear 2B while being guided by the slope 5C provided on the ribbon feed pawl 5.
[0036]
FIG. 8 shows a state in which the pawl 4B of the reverse stop pawl 4 is pressed against the spool gear 2B by the operating force of the reverse stop pawl spring 7 and engages with the ratchet of the spool gear 2B. The reverse rotation preventing claw 4 is a mechanism that is brought into pressure contact with the ratchet of the spool gear 2B by the operating force of the reverse rotation preventing claw spring 7 about the fulcrum pin 8 to engage therewith. Even if the reversing stop claw 4 does not reach the position where it engages with the ratchet of the spool gear 2B, the slope 5C provided on the ribbon feed claw 5 is actuated in the direction of the arrow a to cause the reverse stop claw 4 to move. Is forcibly rotated in the direction of the spool gear 2B, and the reverse rotation preventing claw 4 is engaged with the ratchet of the spool gear 2B.
[0037]
9 to 13 show an operation recovery state of the ribbon feeding claw 5 when the ribbon feeding claw 5 stops during the reversing operation and does not reach a position where it engages with the ratchet of the spool gear 2B.
[0038]
When the ribbon feed pawl fulcrum pin 9 moves in the heart cam 3A of the ribbon feed plate 3 during the ribbon feed switching operation, the timing at which the movement of the ribbon feed plate 3 in the direction of arrow a ends and the ribbon feed pawl When the fulcrum pin 9 is in the vicinity of the center protrusion of the heart cam 3A of the ribbon feed plate 3, the feed claw spring 6 presses the ribbon feed claw 5 against the center protrusion of the heart cam 3A of the ribbon feed plate 3, and the ribbon The feeding claw 5 may be unable to rotate from the center of the heart cam 3A to either direction due to the frictional force caused by the pressure contact (FIG. 9).
[0039]
In this state, no rotational moment is applied to the ribbon feed pawl 5 by the feed pawl spring 6, so that the ribbon feed pawl 5 engages with the spool gear 2A in the lateral direction of the feed spring hooking column 5E of the ribbon feed pawl 5. Determined by the last position.
[0040]
In the recovery of the operation of the ribbon feed claw 5, the ribbon feed plate 3 moves in the direction of the arrow b in the next operation, so that the feed spring hooking column 5E of the ribbon feed claw 5 comes into contact with the slope 1A provided on the ribbon frame 1 ( (FIG. 10). Since the ribbon feed plate 3 moves further in the direction of arrow b, the ribbon feed claw 5 is forcibly rotated clockwise along the slope 1A of the ribbon frame 1. In the embodiment of the present invention, the slopes 1A, 1B provided on the ribbon frame 1 are set to have an inclination width that always comes into contact with the feed spring hook 5E of the ribbon feed claw 5 and that the ribbon feed claw 5 is sufficiently rotated. Further, the slant surfaces 1A and 1B of the ribbon frame 1 are connected by a horizontal line, and a margin is provided so that the ribbon feed claw 5 does not contact the slope 1A of the ribbon frame 1 when the ribbon feed claw 5 is inverted.
[0041]
When the movement of the ribbon feed plate 3 in the direction of the arrow b is completed (FIG. 11), the ribbon feed plate 3 moves in the direction of the arrow a again, and the tip 5A of the ribbon feed claw 5 of the ribbon feed claw 5 engages with the spool gear 2A. (FIG. 12). Therefore, in order to engage the ribbon feed pawl tip 5A with the ratchet of another spool gear 2A further wound, the amount of movement of the ribbon feed plate 3 in the direction of the arrow a is determined by locking the ribbon feed pawl to the spool gear. The amount from when the ribbon feed pawl fulcrum pin 9 has moved from one position of the heart cam 3A of the ribbon feed plate 3 to the other end and the amount that the ribbon feed pawl 5 feeds the ratchet of the spool gear 2A by at least one tooth are adjusted. Set to the amount of movement. Therefore, the ribbon feed claw tip 5A is locked to the spool gear 2A earlier than when the ribbon feed claw 5 stops halfway, and the ribbon feed claw fulcrum pin 9 and the center protrusion of the heart cam 3A of the ribbon feed plate 3 are provided. The ribbon feed pawl fulcrum pin 9 rotates to the left side wall of the heart cam 3A by the operating force of the feed pawl spring 6 (FIG. 13). Thereafter, as described above, the ribbon feed claw 5 rotates in the direction of the spool gear 2B by the operating force of the feed claw spring 6, and engages with the spool gear 2B.
[0042]
According to the above operation, even when the reversing operation of the ribbon feed pawl stops halfway and it is impossible to reach the position where it engages with the ratchet of the spool gear, the operation can be reliably recovered.
[0043]
【The invention's effect】
As described above, according to the above-described configuration of the present invention, the ribbon frame is provided with the rotating inclined surface that is engaged with the ribbon feeding claw and is rotated to the spool gear that rotationally drives the ribbon feeding claw. Even if the reversing operation of the feed pawl stops halfway and it is impossible to reach the position where it engages with the ratchet of the spool gear, the ribbon feed pawl can be reliably engaged with the spool gear in the next operation, No malfunction of the ribbon feeding claw occurs.
The amount of movement of the ribbon feed plate is the amount required for the fulcrum of the ribbon feed pawl to move from one position of the cam of the ribbon feed plate to the other, and the ribbon feed pawl feeds at least one tooth of the ratchet of the spool gear. Since the amount of movement is set to match the amount, the ribbon feed claw can be securely locked at a reversible position, and the ribbon feed claw does not malfunction and its reliability is further improved Is what you do.
[0044]
Also, since the cam portion is a heart shape punched out of a ribbon frame, the ribbon feeding claw can be rotated without applying a load by the cam portion to the side surface of the heart shape, so that the switching of the ribbon feeding claw is smoothly performed, Reliability is improved.
[0045]
In addition, since the ribbon feeding claw is provided with a rotating inclined surface which engages with the reverse rotation preventing claw and rotates to the spool gear which rotationally drives the reverse rotation preventing claw, the rotation of the ribbon feeding claw always causes the reverse rotation. The pawl is also rotated, so that switching failure of the reverse pawl does not occur.
[Brief description of the drawings]
FIG. 1 is a plan view showing a mechanism of an ink ribbon device of a small printer according to the present invention.
FIG. 2 is a plan view showing an operation of starting ribbon feeding.
FIG. 3 is a plan view showing an operation during ribbon feeding.
FIG. 4 is a plan view showing the operation of terminating the ribbon feeding.
FIG. 5 is a plan view showing the beginning of the ribbon feed reversal operation.
FIG. 6 is a plan view showing the middle of the ribbon feed reversal operation.
FIG. 7 is a plan view showing the end of the ribbon feed reversal operation.
FIG. 8 is a plan view showing the end of the reverse rotation preventing claw reversing operation.
FIG. 9 is a plan view showing a state in which the ribbon feeding claw is stopped halfway.
FIG. 10 is a plan view showing the start of the rotation operation of the ribbon feeding claw.
FIG. 11 is a plan view showing the end of the rotation operation of the ribbon feeding claw.
FIG. 12 is a plan view showing an engagement state with the spool gear after the ribbon feeding claw rotating operation.
FIG. 13 is a plan view showing recovery from a partially stopped state of the ribbon feeding claw.
FIG. 14 is a plan view showing an example of a mechanism of an ink ribbon device of a conventional small printer.
FIG. 15 is a plan view showing the start of switching of the ink ribbon according to the related art.
FIG. 16 is a plan view showing a state where the ink ribbon of the related art is being switched.
FIG. 17 is a plan view showing the completion of the conventional ink ribbon switching.
[Explanation of symbols]
1 Ribbon Frame 1A Ribbon Frame Slope 2A Spool Gear 2B Spool Gear 3 Ribbon Feed Plate 3A Ribbon Feed Plate Heart Cam 4 Reverse Stop Claw 5 Ribbon Feed Claw 5A Ribbon Feed Claw Tip 5B Ribbon Feed Claw Tip 5C Ribbon Feed Claw Slope 5D Ribbon Feed Claw Slope 6 feed pawl spring 7 reverse stop pawl spring 8 reverse stop pawl fulcrum pin 9 ribbon feed pawl fulcrum pin

Claims (4)

An ink ribbon device of a printer used while rewinding or winding a pair of ribbon spools on which an ink ribbon impregnated with ink is stretched and reciprocating the ink ribbon,
A pair of ribbon spools that are arranged at both ends of the ink ribbon, the winding start part is fixed, and the ink ribbon is wound,
A ribbon frame which is a base member attached to the printer,
A pair of spool gears around which a ratchet is arranged and rotatably attached to the ribbon frame;
A ribbon feed plate that is externally driven and is movably disposed on the ribbon frame and has a cam portion having two predetermined positions;
A ribbon feeding claw that includes a fulcrum that is movable to the two predetermined positions of the cam portion, engages the ratchet of the spool gear, and rotates the spool;
An urging member attached to the ribbon feeding plate at one end and the ribbon feeding plate at the other end, so as to urge the ribbon feeding claw toward the two predetermined positions;
A reverse stop pawl rotatably disposed on the ribbon frame and engaged with the ratchet of the spool gear to prevent the ribbon feed pawl from rotating in a direction opposite to the direction in which the spool gear rotates. And
The ribbon feed pawl, the fulcrum portion moment direction change by the biasing member and moves from one to the other position of the cam portion, both when changing the spool gear for rotating,
The ribbon frame engages with the ribbon feed pawl when the ribbon feed pawl tip does not engage with the ribbon spool gear, and holds the ribbon such that the ribbon feed pawl tip approaches one of the ribbon spool gears. An ink ribbon device, wherein a rotation inclined surface for rotating a feed claw is arranged . An ink ribbon device of a printer used while rewinding or winding a pair of ribbon spools on which an ink ribbon impregnated with ink is stretched and reciprocating the ink ribbon,
A pair of ribbon spools that are arranged at both ends of the ink ribbon, the winding start part is fixed, and the ink ribbon is wound,
A ribbon frame which is a base member attached to the printer,
A pair of spool gears around which a ratchet is arranged and rotatably attached to the ribbon frame;
A ribbon feed plate that is externally driven and is movably disposed on the ribbon frame and has a cam portion having two predetermined positions;
A ribbon feeding claw that includes a fulcrum that is movable to the two predetermined positions of the cam portion, engages the ratchet of the spool gear, and rotates the spool;
An urging member attached to the ribbon feeding plate at one end and the ribbon feeding plate at the other end, so as to urge the ribbon feeding claw toward the two predetermined positions;
A reverse stop pawl rotatably disposed on the ribbon frame and engaged with the ratchet of the spool gear to prevent the ribbon feed pawl from rotating in a direction opposite to the direction in which the spool gear rotates. And
When the fulcrum moves from one position to the other of the cam, the ribbon feed pawl changes the moment direction by the urging member, and changes the spool gear that is driven to rotate .
The amount of movement of the ribbon feed plate is the amount required for the fulcrum to move from one position of the cam of the ribbon feed plate to the other, and the amount that the ribbon feed pawl feeds the ratchet of the spool gear at least one tooth. An ink ribbon device characterized in that the amount of movement is set in accordance with the following . 3. The ink ribbon device according to claim 1, wherein the cam portion has a heart shape obtained by punching the ribbon feed plate. The ribbon feed pawl, the reverse rotation stop pawl engaging in claim 1 or 2 or 3, wherein rotating the slope of rotating the spool gear for rotating the reverse rotation pawl is characterized in that it is arranged Ink ribbon device.

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