JP2006131391A - Sheet carrying mechanism and recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the service life of a compression coil spring, by restraining a twist of the compression coil spring, thereby restraining the breakage thereof. <P>SOLUTION: This sheet carrying mechanism has a driving roller 22A for carrying a recording sheet; and is constituted by installing a gear 53A for transmitting driving force for driving this driving roller 22A on a roller shaft 32 of the driving roller 22A so as to be positioned outside a side frame 17A; and is characterized in that the compression coil spring 65A is interposed on a concentric circle with the roller shaft 32 between the side frame 17A and the gear 53A, and an end turn part 71 on one end of this compression coil spring 65A is brought into pressure contact with a side frame opposed surface of the gear 53A, and a coil wire 72A extending from an end turn part 72 on the other end, is connected to a boss arranged on the side frame opposed surface of the gear 53A. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet conveying mechanism having a gear to which a driving force for driving a driving roller is transmitted, and a recording apparatus including the sheet conveying mechanism.

  In general, the recording apparatus includes a recording head mounted on a carriage, and a recording wire of the recording head is hit against a recording sheet conveyed on a platen by a sheet conveying mechanism through an ink ribbon fed out from a ribbon cartridge. Thus, a dot impact printer that records an image including text such as characters on a recording sheet is known.

  In this type of sheet conveying mechanism, a drive roller for conveying a recording sheet is provided, and a gear to which a driving force for driving the driving roller is transmitted is located outside the side frame and attached to a roller shaft of the driving roller. What is comprised is known (for example, refer patent document 1).

In this sheet conveying mechanism, when the end of the recording sheet is separated from the driving roller, the driving roller may reversely rotate in the direction opposite to the conveying direction in which the recording sheet is conveyed by the backlash of the gear. Thus, when the drive roller rotates in the reverse direction, the line spacing on the recording sheet recorded by the recording head is clogged, and the recording quality is deteriorated. Therefore, a compression coil spring that presses the gear is interposed between the gear and the side frame, and by applying a load in the roller axial direction to the gear, the reverse of the drive roller when the end of the recording sheet comes off the drive roller. The rotation was suppressed.
JP 2002-19991 A

  However, when driving the drive roller, a force that is pressed by the gear and rotates with the rotation of the gear acts on the end winding portion on the gear side of the compression coil spring. A force that is pressed against the side frame side to suppress rotation acts on the end winding part, and the compression coil spring sometimes twists. When the stress due to the twist is applied to the compression coil spring for a long period of time, the compression coil spring may break due to fatigue.

  Then, the objective of this invention can eliminate the subject which the prior art mentioned above has, suppresses the twist of a compression coil spring, suppresses breakage of a compression coil spring, and can improve the lifetime of a compression coil spring. An object of the present invention is to provide a sheet conveying mechanism and a recording apparatus including the sheet conveying mechanism.

In order to solve the above problems, the present invention includes a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is located outside the side frame, and the roller of the driving roller. In a sheet conveying mechanism configured to be attached to a shaft, a compression coil spring is interposed between the side frame and the gear on a concentric circle with the roller shaft, and one end of the compression coil spring is connected to the side of the gear. The frame is opposed to the frame facing surface, and the other end is connected to a boss provided on the side frame facing surface of the gear.
According to the above configuration, the compression coil spring provided between the side frame and the gear rotates integrally with the gear while pressing the gear, so that the torsion of the compression coil spring can be suppressed. Can improve the service life.

Further, a sheet is provided that includes a driving roller that conveys the recording sheet, and a gear to which driving force for driving the driving roller is transmitted is located outside the side frame and attached to the roller shaft of the driving roller. In the transport mechanism, a compression coil spring is interposed between the side frame and the gear on a concentric circle with the roller shaft, one end of the compression coil spring is pressed against the side frame, and the other end is connected to the side frame. It is characterized by being connected to a boss provided on the frame.
According to the above configuration, the compression coil spring provided between the side frame and the gear is fixed to the side frame while pressing the gear, and the torsion of the compression coil spring can be suppressed. Can improve the service life.

Further, in the sheet conveying mechanism, the other end of the compression coil spring is a coil wire extending from the end winding portion of the compression coil spring to the boss.
According to the said structure, the twist of a compression coil spring can be suppressed effectively by simple process of a compression coil spring, and the lifetime of a compression coil spring can be improved.

Further, in the sheet conveying mechanism, the shaft end of the roller shaft faces the outside of the side frame, and the rotation shaft of the gear engages with the roller shaft from the outside of the side frame with the compression coil spring fitted therein. It is characterized by being attached to the shaft end.
According to the said structure, it is easy to interpose a compression coil spring between a side frame and a gear, can suppress the twist of a compression coil spring easily, and improves the lifetime of a compression coil spring. Can do.

Further, in the sheet conveying mechanism, the rotation shaft of the gear is formed in a cylindrical shape, and the roller shaft is fitted into the inner periphery of the rotation shaft at the tip of the rotation shaft. A claw portion that is hooked on a locking portion provided on the shaft is provided.
According to the said structure, since a gear can be attached or detached further by engaging / disengaging a nail | claw part, attachment / detachment of a gear becomes easy.

A sheet conveying unit having a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is positioned outside the side frame and attached to a roller shaft of the driving roller. In a recording apparatus that includes a mechanism and records an image on a recording sheet conveyed by the sheet conveying mechanism with a recording head, the sheet conveying mechanism compresses concentrically with the roller shaft between the side frame and the gear. A coil spring is interposed, one end of the compression coil spring is pressed against the side frame facing surface of the gear, and the other end is connected to a boss provided on the side frame facing surface of the gear. It is.
According to the above configuration, the compression coil spring provided between the side frame and the gear rotates integrally with the gear while pressing the gear, so that the torsion of the compression coil spring can be suppressed. Can improve the service life.

A sheet conveying unit having a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is positioned outside the side frame and attached to a roller shaft of the driving roller. In a recording apparatus that includes a mechanism and records an image on a recording sheet conveyed by the sheet conveying mechanism with a recording head, the sheet conveying mechanism compresses concentrically with the roller shaft between the side frame and the gear. A coil spring is interposed, one end of the compression coil spring is pressed against the side frame, and the other end is connected to a boss provided on the side frame.
According to the above configuration, the compression coil spring provided between the side frame and the gear is fixed to the side frame while pressing the gear, and the torsion of the compression coil spring can be suppressed. Can improve the service life.

  ADVANTAGE OF THE INVENTION According to this invention, the twist of the compression coil spring which presses a gear can be suppressed, and the lifetime of this compression coil spring can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
[1] First Embodiment FIG. 1 is a front perspective view showing an external appearance of a dot impact printer as a recording apparatus according to the first embodiment, and FIG. 2 is an external perspective view showing a printer main body 11. FIG. 3 is a perspective view of the appearance when the recording sheet pressing portion and the ribbon cassette are removed from the state of FIG. 2, and FIG. 4 is a side sectional view of the printer 10.

  A dot impact printer 10 as a recording apparatus shown in FIG. 1 presses a plurality of recording wires provided in the recording head 18 (FIG. 2) against a recording sheet via an ink ribbon (not shown) fed out from a ribbon cartridge 39. An image including characters is recorded by forming dots on a recording sheet.

  The recording sheet includes a cut sheet cut to a predetermined length and a continuous sheet in which a plurality of sheets are connected. The cut sheet includes, for example, plain paper such as single cut paper and single copy paper, as well as a passbook, a postcard, and an envelope. The continuous paper includes continuous copy paper. The recording sheet S shown in FIG. 1 is a passbook, and a plurality of recording sheets are bound, and a magnetic stripe MS is provided on the bottom surface when the recording surface of the recording sheet is opened.

  As shown in FIG. 1, the printer 10 includes an upper cover 12, an upper case 13, and a lower case 14 as exterior bodies, and a recording sheet S is inserted in front of the upper case 13 and the lower case 14. A manual feed port 15 for discharging is opened.

  As shown in FIG. 2, the printer 10 includes a printer main body 11 that is covered with an upper cover 12, an upper case 13, and a lower case 14 as exterior bodies. The printer main body 11 includes a lower main body portion 11A and an upper main body portion 11B supported by a shaft 11C at a rear end portion of the lower main body portion 11A. The lower main body portion 11A includes an upper case 13 and a lower case. 14 (FIG. 1) and the upper main body 11B is fixed to the upper cover 12 (FIG. 1). When the upper cover 12 is opened, the upper main body 11B rotates about the shaft 11C, and the inside of the printer main body 11 is exposed as shown in FIG.

  2 to 4, the printer main body 11 includes a main body frame including a base frame 16 (FIG. 4), a right side frame 17A, a left side frame 17B and (a pair of side frames), a recording head 18, and A recording mechanism 20 having a carriage 19, a platen 21, a first drive roller 22A (FIG. 4), a first driven roller 22B, a second drive roller 23A, a second driven roller 23B, and a front sheet guide 24 (FIG. 4). , The sheet conveying mechanism 100 including the rear sheet guide 25, the sheet conveying motor 26, and the driving wheel train 27, the alignment plate 28 for aligning the recording sheets S, and the magnetic information of the magnetic stripe MS provided on the recording sheets S. The magnetic data reading unit 29 having a magnetic head 34 for reading or writing, and the floating of the recording sheet S from above when reading / writing magnetic information It has a sheet holding portion 30 to obtain the.

  As shown in FIG. 2, a right side frame 17A and a left side frame 17B are erected and fixed to substantially both ends of the base frame 16 (FIG. 4) of the main body frame. As shown in FIG. 4, a carriage shaft 31 is bridged between the side frames 17A and 17B, and a flat front seat guide 24 and a rear seat guide 25 are fixed between the side frames 17A and 17B. Provided. A planar platen 21 is disposed between the front seat guide 24 and the rear seat guide 25. A recording head 18 is disposed opposite to the platen 21.

  The carriage 19 is slidably inserted into the carriage shaft 31 and has the recording head 18 mounted thereon. The carriage 19 is guided to the carriage shaft 31 via a timing belt (not shown) by forward rotation or reverse rotation of a carriage drive motor (not shown) that drives the carriage 19, and the axial direction of the carriage shaft 31 and the longitudinal direction of the platen 21. The vehicle travels (scans) in a range of a pair of side frames 17A and 17B (FIG. 2) in the main scanning direction that coincides with the direction.

  The platen 21 extends in the traveling direction of the carriage 19 and is formed in a planar shape. Both ends of the platen 21 are urged toward the recording head 18 by an urging spring 41 as an urging member and elastically supported. Yes. The biasing spring 41 is a compression coil spring. The urging force of the urging spring 41 supports the output of the recording wire during the recording operation of the recording head 18. Further, the platen 21 is provided with a biasing spring 41 when the thickness of the recording sheet S changes during conveyance of the recording sheet S or when the recording sheet S having a different thickness is loaded into the printer main body 11. The head is pressed by the tip of the recording head 18 against the force and moves away from the recording head 18. Thus, a constant gap (platen gap) between the tip of the recording head 18 and the recording surface of the recording sheet S is ensured regardless of the thickness of the recording sheet.

  While the recording head 18 travels with the carriage 19 in the main scanning direction, the recording wire protrudes and strikes the ink ribbon, and the ink on the ink ribbon is conveyed between the platen 21 and the recording head 18. An image including characters is recorded on the recording sheet S by being attached to the recording sheet S. The ink ribbon is folded and stored in the ribbon cartridge 39. The ribbon cartridge 39 is attached to the carriage 19 or the main body frame.

  In the sheet conveying mechanism 100, a first driving roller 22A and a first driven roller 22B are disposed on the front side (upstream side) of the printer main body 11 with respect to the platen 21 (recording head 18). Two driven rollers 23B are arranged on the rear side (downstream side) of the printer main body 11 with respect to the platen 21 (recording head 18). The first driving roller 22A and the first driven roller 22B are arranged in the up-down direction to make a pair, and the second driving roller 23A and the second driven roller 23B are arranged in the up-down direction to make a pair.

  Among these, the first driving roller 22A and the second driving roller 23A are arranged below the front sheet guide 24 and the rear sheet guide 25 together with the platen 21, and the first driven roller 22B and the second driven roller 23B are arranged at the front. The seat guide 24 and the rear seat guide 25 are disposed above each other. The first driving roller 22A and the second driving roller 23A are driving rollers that are rotationally driven by the sheet conveying motor 26 (FIGS. 2 and 3) and the driving wheel train 27 (FIGS. 2 and 3), and are first driven. The roller 22B and the second driven roller 23B are driven rollers that are urged by the springs 42A and 42B with a predetermined pressing force toward the first driving roller 22A and the second driving roller 23A, respectively. Thus, the first drive roller 22A and the first driven roller 22B are rotationally driven in opposite directions, and the second drive roller 23A and the second driven roller 23B are rotationally driven in opposite directions.

  As shown in FIG. 2, the drive wheel train 27 is disposed outside the right side frame 17A. As shown in FIG. 5, the drive wheel train 27 is integrally fixed to a drive shaft 26 </ b> A of a sheet conveying motor 26 that can be rotated forward (solid arrow in FIG. 5) or reverse (broken arrow in FIG. 5). The motor pinion 51 is provided. The driving force from the motor pinion 51 is transmitted to the second driving gear 53B attached to the second roller shaft 33 (FIG. 4) of the second driving roller 23A (FIG. 4) via the reduction gear 52, and This second drive gear 53B is transmitted to the drive gear 53A attached to the first roller shaft 32 (FIG. 4) of the first drive roller 22A (FIG. 4) via the intermediate gear. Thereby, the first drive roller 22A and the second drive roller 23A shown in FIG. 4 rotate in the same direction, and the recording sheet S can be conveyed into the printer main body 11. That is, the first drive roller 22A and the second drive roller 23A shown in FIG. 4 are in the direction indicated by the solid arrow A (that is, the direction in which they are transported into the printer main body 11) when the sheet transport motor 26 (FIG. 5) is rotating forward. ), The recording sheet S is conveyed in the direction of the broken line arrow B in FIG. 4 (that is, the direction of discharging from the printer main body 11).

  As shown in FIG. 6, a plurality of (6 in the first embodiment) first drive rollers 22A are fixed to the first roller shaft 32. Similarly, the second drive roller 23A is a second drive roller 23A. A plurality (six in the first embodiment) of the two roller shafts 33 are fixed.

  Between the shaft end 32A on the left side frame 17B side of the first roller shaft 32 and the two adjacent first drive rollers 22A on the first roller shaft 32, a bearing portion 61A provided on the base frame 16 is fitted, The first roller shaft 32 is rotatably supported. The shaft end 32B on the right side frame 17A side of the first roller shaft 32 faces the outside of the right side frame 17A through an opening 62A formed in the right side frame 17A, and the first drive gear 53A is connected to the first roller 53A. The shaft 32 is attached to the shaft end 32B from the outside of the right side frame 17A through the opening 62A.

  Similarly, between the shaft end 33A on the left side frame 17B side of the second roller shaft 33 and the two adjacent second drive rollers 23A on the second roller shaft 33, a bearing portion 61B provided on the base frame 16 is provided. The second roller shaft 33 is fitted so as to be rotatable. The shaft end 33B of the second roller shaft 33 on the right side frame 17A side faces the outside of the right side frame 17A through an opening 62B formed in the right side frame 17A, and the second drive gear 53B is connected to the second roller The shaft 33 is attached to the shaft end 33B from the outside of the right side frame 17A through the opening 62B.

  Next, an outline of the operation of the printer 10 will be described. When the recording sheet S as a passbook is inserted from the manual feed port 15 shown in FIG. 1, the alignment plate 28 shown in FIG. 4 protrudes into the conveyance path, and the recording sheet S is moved to the first driving roller 22A and the first driven roller 22B. And is conveyed in the direction of arrow A to the front of the platen 21.

  Next, the recording sheet S is conveyed in the direction of arrow A by the first drive roller 22A and the first driven roller 22B with the alignment plate 28 protruding in the conveyance path. As a result, the recording sheets S are aligned along the alignment plate 28. Next, the recording sheet S is conveyed in the direction of arrow A by the first driving roller 22A and the first driven roller 22B until the magnetic data reading unit 29 can read the magnetic stripe MS of the recording sheet S.

  Next, after the information is read from the magnetic stripe MS of the recording sheet S by the magnetic data reading unit 29, the recording sheet S is moved in the direction of arrow A to the recording position on the platen 21 by the rollers 22A, 22B, 23A and 23B. The image such as characters is conveyed by the recording head 18.

  In the recording operation by the recording head 18, one line is recorded by the recording wire of the recording head 18 while the recording head 18 travels leftward or rightward in the main scanning direction, and this one-line recording is performed. Each time, the rollers 22A, 22B, 23A, and 23B convey the recording sheet S in the direction of arrow A by a predetermined length (normal line spacing), and these operations are repeated.

  After recording by the recording head 18, the recording sheet S is conveyed to the reading position in the direction of arrow B by the rollers 22A, 22B, 23A and 23B, and is read by the magnetic data reading unit 29 based on the information recorded on the recording sheet S. Magnetic information is written in the magnetic stripe MS. Next, the recording sheet S is conveyed in the direction of arrow B by the first driving roller 22 </ b> A and the first driven roller 22 </ b> B, and the recording sheet S is discharged from the manual feed port 15.

  Printers such as drive control of the first drive roller 22A and second drive roller 23A of the sheet conveying mechanism 100, travel control of the carriage 19, control of recording operation by the recording wire of the recording head 18, and read / write control of the magnetic data reading unit 29 A control board 50 that controls the entirety of the printer 10 is disposed, for example, below the printer main body 11 on the rear side.

  By the way, referring to FIG. 4, when the recording sheet S is conveyed in the direction of arrow A and recording is performed near the rear end of the recording sheet S during the recording operation of the printer 10, the recording sheet S has the first drive roller 22 </ b> A and the The recording sheet S may be transported only by the second driving roller 23A and the second driven roller 23B, deviating from the first driven roller 22B. A backlash exists between the first drive gear 53A (FIG. 5) that transmits the driving force to the first drive roller 22A and the intermediate gear 54 that transmits the driving force to the first drive gear 53A.

  As shown in FIG. 4, since the first driven roller 22B is biased by the spring 42A in the direction of the first drive roller 22A, the recording sheet S is separated from the first drive roller 22A and the first driven roller 22B. At this time, a force pushed in the direction of the arrow A acts on the recording sheet S. As a reaction of this force, a force that the first driving roller 22A rotates in the direction opposite to the direction of the arrow A by the amount of backlash acts. It will be.

  Similarly, the recording sheet S is conveyed in the direction of arrow B, the recording sheet S is detached from the second driving roller 23A and the second driven roller 23B, and the recording sheet S is conveyed only by the first driving roller 22A and the first driven roller 22B. In this case, since the second driven roller 23B is biased by the spring 42B in the direction of the second drive roller 23A, a force that is suddenly pushed in the direction of the arrow B acts on the recording sheet S, and the reaction of this force As a result, a force is applied to the second drive roller 23A to rotate in the direction opposite to the arrow B direction by the backlash of the second drive roller 23A.

  Therefore, as shown in FIG. 6, with the spacer 64A and the compression coil spring 65A fitted into the rotation shaft 63A of the first drive gear 53A, the rotation shaft 63A of the first drive gear 53A is connected to the first roller shaft 32. The shaft end 32B is attached from the outside of the right side frame 17A through the opening 62A. That is, the compression coil spring 65A is interposed on the concentric circle with the first roller shaft 32 between the right side frame 17A and the first drive gear 53A. The first driving gear 53A is pressed in the axial direction of the first roller shaft 32 by the compression coil spring 65A, and the recording sheet S is transferred to the first driving roller 22A by the pressing load applied to the first driving gear 53A by the compression coil spring 65A. And when it remove | deviates from the 1st driven roller 22B, reverse rotation of 22 A of 1st drive rollers is suppressed.

  Similarly, the rotation shaft 63B of the second drive gear 53B is attached to the shaft end 33B of the second roller shaft 33 through the opening 62B from the outside of the right side frame 17A in a state where the spacer 64B and the compression coil spring 65B are fitted. Due to the pressing load applied to the second drive gear 53B by the compression coil spring 65B, the reverse rotation of the second drive roller 23A is suppressed when the recording sheet S is detached from the second drive roller 23A and the second driven roller 23B.

  Here, the spacers 64A and 64B are made of resin and reduce the frictional force between the compression coil springs 65A and 65B and the right side frame 17A.

  7 is a partially exploded perspective view in which the right side frame 17A side is enlarged, and FIG. 8 is a diagram in which a compression coil spring 65A viewed from the direction of arrow X in FIG. 7 is fitted into the rotation shaft 63A of the first drive gear 53A. FIG. 9 is a partial cross-sectional view showing a support state of the first drive roller 22A, which is a main part of the sheet conveying mechanism 100. FIG. The configuration on the first drive gear 53A side and the configuration on the second drive gear 53B side in the sheet conveying mechanism 100 are substantially the same. That is, the first roller shaft 32 and the second roller shaft 33 are the same member, and the first drive gear 53A and the second drive gear 53B are the same member, and the compression coil spring 65A and the compression coil spring 65B. Since these are the same members, the configuration on the first drive gear 53A side of the sheet conveying mechanism 100 will be described below, and the description and illustration of the configuration on the second drive gear 53B side will be omitted.

  The end winding portion 71 that is one end of the compression coil spring 65A shown in FIG. 7 is in pressure contact with the side surface 81 of the first drive gear 53A that faces the right side frame 17A shown in FIG. 9, and is the other end of the compression coil spring 65A. The end turn portion 72 is in pressure contact with the right side frame 17A via a spacer 64A. As shown in FIGS. 8 and 9, a boss 82 is formed on the side surface 81 of the first drive gear 53A, and the compression coil spring 65A extends from the end winding portion 72 of the compression coil spring 65A toward the side surface 81. An outgoing coil wire 72A is formed. As shown in FIG. 9, the coil wire 72 </ b> A extending from the end turn portion 72 has a compression coil spring 65 </ b> A sandwiched between the first drive gear 53 </ b> A and the right side frame 17 </ b> A and compressed. It is connected to the boss 82 of 53A. Thus, when the recording sheet S is conveyed, the compression coil spring 65A rotates integrally with the first drive gear 53A while pressing the side surface 81 of the first drive gear 53A, and the compression coil spring 65A is twisted. Since the breakage of the compression coil spring 65A is suppressed, the life of the compression coil spring 65A can be improved.

  Further, since the coil wire 72A need only be extended at the end winding portion 72 of the compression coil spring 65A, the compression coil spring 65A can be easily processed.

  Further, since the resin spacer 64A is interposed between the end winding portion 72 of the compression coil spring 65A and the right side frame 17A, when the recording sheet S is conveyed, the end winding of the compression coil spring 65A is performed. The portion 72 slides smoothly, can effectively rotate the compression coil spring 65A together with the first drive gear 53A, and can effectively suppress the twist of the compression coil spring 65A.

  In the first embodiment, the rotation shaft 63A of the first drive gear 53A is formed in a cylindrical shape and is erected on the side surface 81 facing the right side frame 17A. A hook-like claw portion 83 is formed at the tip of the rotating shaft 63A, and a locking portion 32C on which the claw portion 83 is hooked is formed near the shaft end 32B of the first roller shaft 32.

  When the first drive gear 53A is attached to the shaft end 32B of the first roller shaft 32, the first drive gear is fitted with the compression coil spring 65A and the spacer 64A fitted on the rotary shaft 63A of the first drive gear 53A. The rotation shaft 63A of 53A is inserted into the opening 62A from the outside of the right side frame 17A, so that the rotation shaft 63A protrudes to the inside of the right side frame 17A, and is formed on the inner periphery 84 of the rotation shaft 63A of the first drive gear 53A. The shaft end 32B of the first roller shaft 32 is fitted, and the claw portion 83 of the first drive gear 53A is hooked on the locking portion 32C of the first roller shaft 32. Further, when removing the first drive gear 53A from the first roller shaft 32, it is only necessary to remove the claw portion 83 of the first drive gear 53A that is hooked on the locking portion 32C of the first roller shaft 32. Therefore, the first drive gear 53A can be easily attached and detached, and the assembly and disassembly of the first drive gear 53A to the first roller shaft 32 are improved. This facilitates replacement of the compression coil spring 65A.

  Further, since the side surface 81 of the first drive gear 53A is pressed by the compression coil spring 65A, the claw portion 83 of the first drive gear 53A is pressed against the locking portion 32C of the first roller shaft 32. Thus, the first drive gear 53A is more firmly attached to the first roller shaft 32.

  In the first embodiment, a burring process is performed in which the peripheral portion of the opening 62A of the right side frame 17A is bent to the inside of the right side frame 17A. Thereby, it is not necessary to provide a bush in the opening 62A, and the number of parts can be reduced.

  Further, since the first drive gear 53A and the second drive gear 53B are the same member, and the compression coil spring 65A and the compression coil spring 65B are the same member, the parts can be shared.

[2] Second Embodiment In the first embodiment, the case where the compression coil spring is connected to the boss of the drive gear has been described. However, in the second embodiment, the compression coil spring is connected to the boss of the side frame. A description will be given of the case. Hereinafter, in this 2nd Embodiment, the part similar to the said 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  FIG. 10 is a partial cross-sectional view showing a support state of the first drive roller 22A, which is a main part of the sheet conveying mechanism in the second embodiment. In FIG. 10, the end winding portion 171 as one end of the compression coil spring 165A is in pressure contact with the right side frame 117A, and the end winding portion 172 as the other end is in pressure contact with the side surface 181 of the drive gear 153A.

  On the right side frame 117A, a boss 182 is formed in the vicinity of the opening 62A. On the other hand, a coil wire 172A extending in the direction of the right side frame 117A is formed from the end winding portion 172 of the compression coil spring 165A. The coil wire 172A is coupled to the boss 182 of the right side frame 117A in a state where the compression coil spring 165A is sandwiched and compressed between the first drive gear 153A and the right side frame 117A. As a result, the compression coil spring 165A presses the side surface 181 of the first drive gear 153A, and the compression coil spring 165A is fixed to the right side frame 117A. As in the first embodiment, the compression coil spring 165A is compressed. The twist of 165A can be suppressed, breakage of the compression coil spring 165A can be suppressed, and the life of the compression coil spring 165A can be improved.

  As mentioned above, although this invention was demonstrated based on one Embodiment, this invention is not limited to this. In the first and second embodiments, the case where the gear is provided outside the right side frame has been described, but the present invention can also be applied to the case where the gear is provided outside the left side frame.

  In the first and second embodiments, the case where the end winding portions 71 and 172 of the compression coil springs 65A and 165A are in direct contact with the gears 53A and 153A has been described. However, the end winding portions of the gear and the compression coil spring are described. Even when a spacer or the like is interposed between them, the compression coil spring substantially presses the gear.

  In the first and second embodiments described above, the case where the burring process is performed in the opening 62A of the side frame and the bushing can be omitted has been described. The present invention can also be applied when intervening.

  In the first and second embodiments, the case where the rotating shaft 63A of the gears 53A and 153A protrudes inside the side frames 17A and 117A and is attached to the shaft end 32B of the roller shaft 32 has been described. The present invention is applicable even when the shaft end of the shaft protrudes outward from the side frame and a gear is attached to the shaft end.

  Further, in the first and second embodiments, the compression coil springs 65A and 165A are provided between the gears 53A and 153A located outside the side frames 17A and 117A and the side frames 17A and 117A. The case where the coil wires 72A and 172A extending from the boss 82 and 182A are fixed to the bosses 82 and 182 provided at the other end has been described. If a compression coil spring is provided between the portions and a coil wire extending from one of the seating surfaces is fixed to a boss provided at the other end, the same effect can be obtained, so that the present invention can be applied.

1 is a front perspective view illustrating an appearance of a printer as a recording apparatus according to a first embodiment of the invention. 1 is an external perspective view showing a printer main body. FIG. 3 is an external perspective view when a recording paper pressing unit and a ribbon cassette are removed from the state of FIG. 2. It is a sectional side view of a printer. It is a top view which shows a drive wheel train part. FIG. 6 is a partial exploded perspective view showing a main part of a sheet conveying mechanism. It is the partial exploded perspective view which expanded the right side frame side. It is a top view which shows the state by which the compression coil spring seen from the arrow X direction of FIG. 7 is engage | inserted by the rotating shaft of the 1st drive gear. FIG. 5 is a partial cross-sectional view illustrating a support state of a first drive roller that is a main part of a sheet conveying mechanism. It is a fragmentary sectional view showing the support state of the 1st drive roller which is the principal part of the sheet conveyance mechanism in a 2nd embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer (recording apparatus), 17A, 117A ... Right side frame, 17B ... Left side frame, 18 ... Recording head, 22A ... First drive roller (drive roller), 23A ... Second drive roller, 32 ... First roller Shaft (roller shaft), 32B ... shaft end, 32C ... locking portion, 33 ... second roller shaft (roller shaft), 33B ... shaft end, 53A ... first drive gear (gear), 53B ... second drive gear ( Gear), 63A, 63B ... rotating shaft, 65A, 65B, 165A ... compression coil spring, 71, 72, 171, 172 ... end winding, 72A, 172A ... coil wire, 81, 181 ... side surface (side frame facing surface) , 82, 182... Boss, 83... Claw portion, 100.

Claims (7)

A sheet conveying mechanism including a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is located outside the side frame and attached to the roller shaft of the driving roller. In
A compression coil spring is disposed concentrically with the roller shaft between the side frame and the gear, one end of the compression coil spring is pressed against the side frame facing surface of the gear, and the other end is connected to the gear. A sheet conveying mechanism characterized in that it is connected to a boss provided on the side frame facing surface. A sheet conveying mechanism including a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is located outside the side frame and attached to the roller shaft of the driving roller. In
A compression coil spring is disposed concentrically with the roller shaft between the side frame and the gear, one end of the compression coil spring is pressed against the side frame, and the other end is provided on the side frame. A sheet conveying mechanism connected to a boss.   The sheet conveying mechanism according to claim 1, wherein the other end of the compression coil spring is a coil wire extending from the end winding portion of the compression coil spring to the boss. The shaft end of the roller shaft faces the outside of the side frame,
The rotating shaft of the gear is attached to the shaft end of the roller shaft from the outside of the side frame in a state in which the compression coil spring is fitted. The sheet conveying mechanism according to item. The rotation shaft of the gear is formed in a cylindrical shape,
The tip of the rotating shaft is provided with a claw portion that is hooked to a locking portion provided on the roller shaft when the shaft end of the roller shaft is fitted on the inner periphery of the rotating shaft. The sheet conveying mechanism according to claim 4. A sheet conveying unit having a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is positioned outside the side frame and attached to a roller shaft of the driving roller. In a recording apparatus that includes a mechanism and records an image with a recording head on a recording sheet conveyed by the sheet conveying mechanism,
The sheet conveying mechanism is provided with a compression coil spring concentrically with the roller shaft between the side frame and the gear, and one end of the compression coil spring is pressed against the side frame facing surface of the gear, The other end is connected to a boss provided on the side frame facing surface of the gear. A sheet conveying unit having a driving roller for conveying a recording sheet, and a gear to which a driving force for driving the driving roller is transmitted is positioned outside the side frame and attached to a roller shaft of the driving roller. In a recording apparatus that includes a mechanism and records an image with a recording head on a recording sheet conveyed by the sheet conveying mechanism,
The sheet conveying mechanism has a compression coil spring interposed on the concentric circle with the roller shaft between the side frame and the gear, one end of the compression coil spring is pressed against the side frame, and the other end is A recording apparatus connected to a boss provided on the side frame.

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