JPH023880Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer, and more particularly to a multi-stage printer having a type body in which type parts are arranged in multiple stages along the paper feeding direction of printing paper.

Next, a multistage printer according to an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram of the printer.

[Schematic configuration]

A driving pulley 1 and a driven pulley 2 are arranged at a predetermined interval, and two endless type belts 3 as shown in FIGS. 2 and 3 are placed between them.
A and 3b are strung across in two tiers, upper and lower.
A worm 5 is attached to the rotating shaft of one DC motor 4 serving as a drive source, and the driving force of the motor 4 is transmitted to a main gear 8 via a first idle gear 6 and a second idle gear 7. The rotational force from the main gear 8 is transmitted to the drive pulley 1 via a spring clutch (not shown), and a print/carry gear 9 is meshed with the main gear 8. It's summery.

One end of a printing/carrying shaft 10 is connected to the printing/carrying gear 9, and a hammer holder 11 is attached to the printing/carrying shaft 10 so as to be slidable in the axial direction.
It has a built-in hammer 19 and carry cam 22.
Supported. One end of a return spring 12 is connected to the hammer holder 11, and the other end of the return spring 12 is fixed to a base (not shown). Therefore, the hammer holder 11 is moved to the home near the driven pulley 2 by the tensile force of the return spring 112. It is always elastically biased towards the position side.

A rack 13 is arranged near and parallel to the print/carry shaft 10, so that the aforementioned carry cam 22 and the rack teeth of the rack 13 can mesh with each other. Behind the rack 13, a paper feed roller 14 and a flat guide plate 15 which also serves as a platen are arranged.
It is sent out from below and guided near the outside of the type belt 3. Reference numeral 17 denotes a selection lever for switching and transmitting the rotational force of the main gear 8 from the drive pulley 1 to the print/carry gear 9 at a predetermined timing, and its operation is controlled by the first electromagnetic solenoid 18. controlled. 20a and 20b are ink rollers provided in upper and lower stages to face the type belts 3a and 3b.
It comes into elastic contact with the type portion 21 (see FIG. 2) on the outer peripheral surface of the letters a and 3b to apply ink to the type surface. The upper ink roller 20a is impregnated with, for example, black ink, and the lower ink roller 20b is impregnated with, for example, red ink, so that two-color printing is possible.

Reference numeral 23 denotes a shift gear, to which the rotational force from the main gear 8 is transmitted via the third idle gear 24, but when the hammer 19 is not being shifted, the shift gear 23 is shifted to the third idle gear 2.
4 and is in a non-meshing state. A rotary lever 25 controls the rotation and stopping of this shift gear 23.
This is rotated by the second electromagnetic solenoid 26.

Reference numeral 27 denotes a control gear whose rotation is controlled in relation to the on/off operations of the rotary lever 25 and the on/off operations of the gear clutch lever 28. This control gear 27
The paper feed cam portion 29 (see FIG. 2) can mesh with an intermediate gear 30 that rotates integrally with the paper feed roller 14, and the paper feed roller 14 is rotated through the intermediate gear 30 by the rotation of the control gear 27. By rotating, a paper feed operation is performed by a predetermined amount.

As shown in Figure 3, from "0" to "9"
A numeric character group having 10 types of numeric character parts and a symbol character group such as "+", "-", "x", etc. are arranged in a predetermined order, and the upper type character belt 3a
and the lower type belt 3b have the same type arrangement.

FIG. 4 is a flowchart showing a power transmission system from the DC motor 4. As shown in the figure, the type belt 3 is driven via the drive pulley 1 and the like by controlling the first electromagnetic solenoid 18 to turn on and off. The rotation of the carry cam 22 is controlled by the on/off control of the first electromagnetic solenoid 18.
This is done via a carry gear 9 or the like. The paper feed roller 14 is rotated via a control gear 27 and the like by controlling the first electromagnetic solenoid 18 and the second electromagnetic solenoid 26 to turn on and off. Further, the shifting operation of the hammer 19 is performed via the shift gear 23 and the like by controlling the second electromagnetic solenoid 26 to turn on and off.

The series of basic operations of this printer consists of type selection operation, hammer shift operation, print/carry operation, paper feed operation, and hammer holder return operation, and each of these operations is repeated sequentially. This allows printing of multiple lines in two colors.

The type selection mechanism includes a code plate 3 that is connected to a main gear 8 and rotates integrally with the main gear 8, as shown in FIG.
1, a sensor gear 32 that meshes with the sensor gear 1, and a plurality of contact pieces (not shown) that come into elastic contact with the code plate 31 and the sensor gear 32. By first detecting the reference position of the type belt 3 by these type selection mechanisms and counting subsequent pulses corresponding to the type portion from the reference position detection pulse, a desired type is selected and the type portion 21 is moved to the hammer 19. The type belt 3 is transferred to a position facing the
rotation is stopped.

[Hammer shift mechanism]

Next, the shift mechanism of the hammer 19 will be explained. As shown in FIG. 1, the shift gear 23
Power can be transmitted from the main gear 8 via the idle gear 24.

FIG. 5 is a diagram showing the shift gear 23. FIG. 5A is a plan view of the shift gear 23, FIG. D is a cross-sectional view on the line K-N in Fig. 5 A, E is a cross-sectional view on the H-H line in Fig. 5 A,
The same figure is a developed view of the shift gear cam groove.

As shown in A and B of the figure, a spring hook protrusion 33 is provided on the upper surface of the shift gear 23 at an eccentric position, and when one end of a tension spring is hooked onto this protrusion, the shift gear 23 is elastically biased in a predetermined direction. be done. An annular cam groove 34 is formed on the upper peripheral surface of the shift gear 23 over the entire circumference, and includes an upper position flat cam groove 34a, a downwardly inclined cam groove 34b, a lower position flat cam groove 34c, and an upwardly inclined cam groove 34.
d, and each of these cam grooves 34a to 34d is formed continuously in the circumferential direction.

Below the cam groove 34, as shown in FIG. As shown in FIG.
b is formed. Below the gear part 37, there are two
Two locking protrusions 38a and 38b are provided, and these can be engaged with the left claw portion 39 of the rotating lever 25.

This rotation of the shift gear 23 causes the first shift cam gear 40 and the second shift cam gear 41 to
(see FIG. 2 for both) is designed to rotate by a predetermined angle. The first shift cam gear 40 is fan-shaped, has a support shaft 42 protruding from its base, an arcuate toothed portion 43 on its outer periphery, and a pin 44 that extends from the side at an intermediate position between the support shaft 42 and the arcuate toothed portion 43. It protrudes toward the shift gear 23. The pin 44 is
Cam grooves 34a to 34d of the rotating shift gear 23
is slidably inserted into the

The second shift cam gear 41 is also fan-shaped, and has an oval-shaped through hole 45 bored at its base, and an arc-shaped tooth portion 46 that meshes with the arc-shaped tooth portion 43 of the first shift cam gear 40 at its outer periphery. It is formed.
One end 48 of the shift cam 47 located on the rotation center line is tightly fitted into the through hole 45, so that the first shift cam gear 41 and the shift cam 47 rotate together. The shift cam 47 is provided with a shift cam portion 49 having a substantially semicircular side surface along its longitudinal direction, and its length is designed to be equal to or slightly longer than the width of one line to be printed. .

As shown in FIGS. 6 and 7, the lower end of the belt pressing body 50 of the hammer 19 is in contact with the outer peripheral cam surface of the shift cam portion 49, and although not shown, the belt pressing body 50 is always elastic downward with a tension spring. Therefore, the lower end of the belt pressing member 50 is always in elastic contact with the shift cam portion 49. The hammer 19 is composed of a belt pressing body 50 and an extrusion body 51. Although not shown, a dovetail groove penetrating vertically is formed on the front surface of the extrusion body 51, while the extrusion body 51 of the belt pressing body 50 and A protrusion is provided on the joining side to be inserted into the dovetail groove. Therefore, due to the engagement between the protrusion and the dovetail groove, the belt pressing body 50 moves back and forth together with the extrusion body 51, and the belt pressing body 50 moves forward and backward together with the extrusion body 51.
It can be moved up and down. The hammer 19 is housed in the hammer holder 11, and the hammer 19 is elastically biased toward the hammer holder 11, that is, in a direction away from the paper 16, by a tension spring stretched between the hammer 19 and the hammer holder 11.

FIG. 6 shows a state in which the lower type belt 3b is selected and the belt pressing body 50 is opposed to the lower type belt 3b. At this time, as shown in FIG.
5a [see Figure 5 E] is the third idle gear 24
(See Figure 1). Therefore, the shift gear 23 is in a stopped state, the belt pressing body 50 is held in a state facing the lower type belt 3b, and at this time the pin 44 is located in the lower flat cam groove 34c.

When the upper type belt 3a is selected and used for printing, the hammer 1 is pressed prior to the printing operation.
9 shift operations are performed. That is, the second electromagnetic solenoid 26 is activated based on a shift signal from the control section.
is excited, which causes the rotation lever 25 to rotate, and its left claw portion 39 disengages from the first locking protrusion 38a. When the lock is released, the shift gear 23 rotates a little due to the tension of the spring, and the spur gear part 36 located between the first toothless part 35a and the second toothless part 35b shown in FIG. It meshes with 24. Since the third idle gear 24 is rotated by power transmission from the main gear 8, the shift gear 23 is rotated by meshing with the third idle gear 24.

The first shift cam gear 40 is pulled downward by a tension spring, and thereby the pin 44 is inserted into the cam groove 34 of the shift gear 23. As the shift gear 23 rotates, the pin 44 is inserted into the cam groove 34. As shown in FIG.
Leading to a. By changing the engagement partner of the pin 44 from the lower flat cam groove 34c to the upper flat cam groove 34a, the first shift cam gear 40 is moved from the support shaft by the difference in height between the lower flat cam groove 34c and the upper flat cam groove 34a. It rotates clockwise around 42. With this rotation, the second shift cam gear 41 shifts to the shift cam 47.
The belt presser 50 is rotated counterclockwise at the same time as shown in FIG. When the belt pressing body 50 faces the upper type belt 3a in this manner, the left claw portion 39 of the rotary lever 25 engages with the second locking protrusion 38b (see FIG. 5E), and as shown in FIG. The second missing tooth portion 35b shown in C is the third
Opposed to the idle gear 24, the shift gear 23 stops rotating.

In this way, the hammer shift mechanism turns on the second electromagnetic solenoid 26 to rotate the shift gear 23, and shifts the belt pressing body 50 upward or downward via the first shift cam gear 40, the first shift cam gear 41, and the shift cam 47. I'm starting to let them do it.

[Print/carry mechanism]

Next, the printing/carrying operation will be explained. The hammer 19 and the carry cam 22 are housed in the hammer holder 11, and the carry cam 22 is splined to the print/carry shaft 10.

As shown in FIG. 2, the carry cam 22 includes a hammer drive portion 52 extending in one direction from the center toward the outer circumference, and a carry protrusion 5 provided along the outer circumference.
3, and a rack rotation part 54 for restoring the rack, which is shaped like an inertial circle. The carry protrusion 53 includes a circumferentially extending circumferential protrusion formed over about half of the circumferential direction, and a spirally extending circumferential protrusion formed over about the remaining half of the circumferential direction. It consists of a spiral protrusion, and both of these protrusions are continuous.
This carry protrusion 53 corresponds to the rack tooth 5 of the rack 13.
It is designed to mesh with 5. The rack rotating portion 54 is adapted to abut against a return lever portion 56 provided at the end of the rack 13.

The rack 13 is arranged near the print/carry shaft 10 and parallel to it so as to be rotatable by a predetermined angle, and as the rack rotates, the rack teeth 55 mesh with the carry protrusion 53 of the carry cam 22, or The engagement may be released.

FIGS. 8A and 8B are diagrams for explaining the printing operation, in which FIG. 8A shows the state before printing, and FIG. 8B shows the state during printing. In the state before printing, as shown in FIG. 1A, the hammer 19 is pulled rearward by a tension spring, and is positioned by a stopper (not shown). Therefore, the type belt 3 is located between the paper 16 and the belt pressing member 50 and is slightly separated from both, and the hammer drive section 52 faces downward and is connected to the receiving section 57 of the hammer 19.
It is not in contact with

The print/carry shaft 10 is rotated in the direction of the arrow by the drive transmitted from the main gear 8, and the return operation of the rack 13 and the printing operation are performed continuously in the first half of the rotation, and the carry operation is performed in the second half of the rotation. It's starting to become easier. That is, when the print/carry shaft 10 rotates in the direction of the arrow, the carry cam 22 also rotates, and at the beginning of the rotation, the return lever part 56 is moved by the easy rotation part 54.
is kicked up, whereby the rack 13 returns to its original position, and the rack teeth 55 and the carry protrusions 53 engage with each other.
During this first half-circle, the circumferential protrusion of the carry protrusion 53 is engaged with the rack teeth 55, so the carry cam 22 (along with the hammer holder 11 and hammer 19) is not moved and It's only half a turn. At half the turn of this carry cam 22, the eighth
As shown in the figure, the hammer driving section 52 comes into contact with the receiving section 57 of the hammer 19, and as the hammer driving section 52 continues to rotate, the hammer 19 is pushed forward against the elasticity of the tension spring. The printing portion 21 of the upper type belt 3a that is selected and faces the paper 16 is pressed against the paper 16 by the extrusion of the hammer 19, and desired printing is performed. As the carry cam 22 rotates, the hammer driving section 52 moves upward, and the hammer 19 is pulled rearward by the tension spring, and the hammer 19 is separated from the type belt 3.

When the carry cam 22 continues to rotate, the spiral protrusion of the carry protrusion 53 meshes with the rack teeth 55, and as the carry cam 22 rotates, the hammer holder 11, the hammer 19, and the like resist the elasticity of the hammer return spring 12. The carry cam 22 moves in the direction of the upper digit by an amount equivalent to one digit and is carried up. By sequentially repeating the printing operation and carry operation in this way, one line is printed.

[Paper feeding mechanism]

Next, the paper feeding operation will be explained. As described above, when one line of printing is completed, it is necessary to return the hammer holder 11 to the home position and feed the paper in preparation for printing the next line. The shape of the control gear 27 will be explained with reference to FIG. 9. Figure A is a front view of the main part of the control gear 27 cut away, Figure B is a bottom view of the control gear 27, Figure C is a sectional view taken along the line H--H of Figure 9A, and Figure D is a cross-sectional view of Figure 9. Fig. 9A is a cross-sectional view taken along the line K-N, Fig. 9E is a cross-sectional view taken along the line H-H of Fig. 9A, and Fig. 9H is a cross-sectional view taken along the line H-H of Fig. 9A.

A single gear part 58 having one tooth in the circumferential direction is provided at the top of the control gear 27, and a spur gear part 60 having a missing tooth part 59 is formed below the single gear part 58. It is designed to be able to mesh with the sensor gear 32. There is a cylindrical part 61 below the spur gear part 60, and further below that a locking protrusion 62 that protrudes outward in the circumferential direction is provided. This locking protrusion 62 is adapted to engage with a right claw portion 63 of the rotating lever 25. A paper feed cam portion 29 is formed below the locking protrusion 62 and extends spirally along the circumferential direction, and has a starting end 29a and a terminal end 29b.
A cutout portion 29c is provided between the two. A non-circular fitting hole 64 is formed in the center of the control gear 27, and a spring hook 65 is protruded from the lower surface at a position slightly offset from the center. Spring hanging pin 6
5 is hung by one end of a tension spring (not shown), and the control gear 27 is urged to rotate in one direction by this spring.

As shown in FIG. 2, above the control gear 27,
A reset plate 66 is arranged. A connecting shaft 67 having the same shape as the insertion hole 64 of the control gear 27 is superimposed on the center of the lower surface of the reset plate 66, and by firmly fitting it into the insertion hole 64, the reset plate 66
rotates integrally with the control gear 27. Reset plate 66
One protrusion 67 is provided on the upper surface near the outer periphery, and a locking portion 68 is formed on the outer periphery. This locking portion 68 is connected to the gear clutch lever 28.
It is adapted to engage with a locking end 69 of.

FIGS. 10A and 10B are diagrams for explaining the paper feeding operation. FIG. 10A shows the state before the paper feeding operation, and FIG. 10B shows the state during the paper feeding operation. In the state before paper feeding, the second electromagnetic solenoid 26 is not energized, so the rotation lever 25 is urged to rotate in one direction by the tension spring, and the right claw portion 63 of the rotation lever 25 is biased to rotate in one direction.
is engaged with the locking protrusion 62 of the control gear 27.
Due to this engagement, the control gear 27 is stopped from rotating.
A toothless portion 59 shown in FIG. 9D faces the tooth portion of the sensor gear 32. Therefore, the rotational driving force from the sensor gear 32 is not transmitted to the control gear 27, and is transmitted to the control gear 27, the intermediate gear 30, and the paper feed roller 1.
4 is in a stationary state and paper is not fed.

When paper is fed, the second electromagnetic solenoid 26 is energized, but prior to this, the gear clutch lever 28 moves as the print/carry shaft 10 rotates, and the locking end 69 of the gear clutch lever 28 moves as the print/carry shaft 10 rotates. The reset plate 66 is separated from the locking portion 68 and the engagement is released. In this state, the second electromagnetic solenoid 26 is energized, the rotating lever 25 rotates against the elasticity of the tension spring, and the right claw portion 63 disengages from the locking protrusion 62. Then, the control gear 27 is slightly rotated by the tension spring, and the spur gear portion 60 shown in FIG. 9D meshes with the sensor gear 32, causing the control gear 27 to rotate. With this rotation, the paper feed cam portion 29 engages with the teeth of the intermediate gear 30, and the intermediate gear 30 and the paper feed roller 14 are rotated in a predetermined direction to perform a paper feed operation.

In the above embodiment, a case has been described in which the hammer 19 is shifted in the vertical direction via the shift gear 23, the first shift cam gear 40, the second shift cam gear 41, the shift cam 47, etc., but the present invention is not limited to these. do not have. That is, the proximal end of the shift lever member is rotatably supported, the distal end thereof supports a type body in which type portions are arranged in multiple stages, and a pin-shaped insert, for example, is inserted into the intermediate portion of the shift lever member. Provide an edge. On the other hand, a shift cam groove into which the insertion end is slidably inserted is formed on the circumferential surface of a shift rotating body such as a shift gear, and the rotation of the shift rotating body shifts the type through a shift lever member. You can also do that.

FIG. 11 is an operation explanatory diagram showing a comparative example of the shift gear 70. In this example, shift gear 70
An upper flat cam surface 71a, a lower inclined cam surface 71b, a lower flat cam surface 71c, and an upward inclined cam surface 71d are successively formed on the upper surface in the circumferential direction.

A pin 73 is protruded from the side surface of the first shift cam gear 72, and the pin 73 is connected to the cam surface 7 of the shift gear 70.
1. It is designed to slide on top. In order to improve the ability of the pin 73 to be added to the cam surface 71, the tip end side of the first shift cam gear 72 is pulled by a tension spring 74, and the pin 73 is in elastic contact with the cam surface 71. As the shift gear 70 rotates, the pin 73
As the sliding cam surface changes, the first shift cam gear 72 rotates about the support shaft 75, and the hammer is shifted.

By the way, in this structure, since the pin 73 is always in elastic contact with the cam surface 71 due to the tensile force of the tension spring 74, the frictional force between the pin 73 and the cam surface 71 is large. Therefore, there is a problem that the rotational speed of the shift gear 70 becomes slow and the shifting operation of the hammer takes time.

As described above, the present invention consists of printing paper that is fed in a predetermined direction, a paper feeding means for feeding the printing paper, and a type body in which type parts are arranged in multiple stages along the paper feeding direction of the printing paper. A multi-stage printer comprising: a hammer body that presses one of the typefaces selected from the typefaces onto the printing paper to perform desired printing; and a shift means that shifts the hammer body in the paper feeding direction. In the above, the shifting means comprises:
It has a shift lever member such as a shift cam gear that is rotatably supported and has a pin-shaped insertion end in a part thereof, and a shift rotating body such as a shift gear that has a shift cam groove formed on the outer periphery, The insertion end of the shift lever member is slidably inserted, and by rotating the shift rotating body, the engagement position between the insertion end and the shift cam groove is changed, the shift lever member is rotated in a desired direction, and the hammer body is rotated. It is characterized by performing a shift operation.

Since the insertion end of the shift lever member is simply inserted into the shift cam groove of the shift rotating body, the frictional force between the insertion end and the shift cam groove is smaller than that of the comparative example, and therefore the shift rotation body and The shift lever member rotates smoothly and the hammer body has good shift operability.

In addition, in order to further reduce the frictional force between the insertion end and the shift cam groove, the shift rotating body or (and) shift lever member is made of polyacetal resin or fluorocarbon resin mixed with fluororesin, molybdenum disulfide, phosphorous graphite, etc. It is best to mold it with a material with good lubricity, such as

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a printer according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of essential parts of the printer, Fig. 3 is a schematic perspective view of a type belt used in the printer, and Fig. 4. 5A is a flowchart showing the power transmission system from the DC motor, FIG. 5A is a plan view of the shift gear, FIG. - A cross-sectional view on the line C, D is a cross-sectional view on the line N-N in FIG. 5 A, E is a cross-sectional view on the H-H line in FIG. FIG. 6 and FIG. 7 are operation explanatory diagrams for explaining the shifting operation of the hammer;
8A and 8B are operation explanatory diagrams for explaining the printing operation, FIG. Figure 9A is a cross-sectional view taken along the line H-H, and Figure D is a cross-sectional view taken along the line H-H in Figure 9A.
Figure 10 is a sectional view taken along the line 2, E is a sectional view taken along the line H-H of Figure 9A, H is a sectional view taken along the H-H line of Figure 9A, and Figures 10A and 10B illustrate the paper feeding operation. FIG. 11 is an operation explanatory diagram showing a comparative example of the shift gear 70. 3a, 3b...Type belt, 14...Paper feed roller, 16...Paper, 19...Hammer, 21...
Type part, 23...Shift gear, 27...Control gear, 29...Paper feed cam part, 34, 34a-34
d...Cam groove, 40, 41...Shift cam gear,
47...Shift cam.

Claims (1)

[Scope of utility model registration request] A printing paper sent in a predetermined direction, a paper feeding means for feeding the printing paper, a type body in which type parts are arranged in multiple stages along the paper feeding direction of the printing paper, and one of the type bodies. A multi-stage printer comprising a hammer body that presses a selected type portion against the printing paper to perform desired printing, and a shift means that shifts the hammer body in the paper feeding direction, wherein the shift means rotates. It has a shift lever member that is movably supported and has an insertion end in a part thereof, and a shift rotating body that has a shift cam groove formed on its outer periphery,
The insertion end of the shift lever member is slidably inserted into the shift cam groove, and by rotating the shift rotating body, the engagement position between the insertion end and the shift cam groove is changed, and the shift lever member is rotated in a desired direction. A multi-stage printer characterized in that it is configured to at least perform a shift operation.