JPS5849289A - Small sized serial printer - Google Patents

Abstract

PURPOSE:To provide a printer ensuring that a paper-feeding operation is conducted by a construction wherein the printer is equipped with a clutch gear in such a manner that the gear is caused to engage with a carriage when the carriage is moved to a predetermined position and a worm gear for feeding printing paper, the worm gear being interlockingly operated through a spring clutch. CONSTITUTION:A printer provided with a drive gear 33 engaging with a drum gear 13 incorporated with a type drum and a clutch gear 43 caused to engage with a carriage when the carriage is moved to a predetermined position, the clutch gear being provided on the frame side of the printer. The printer is further equipped with a worm gear 46 for feeding printing paper, the worm gear being operated interlockingly with the clutch gear 43 through a spring clutch to cause a paper-feeding roller 50 to rotate through a gear 49 for feeding printing paper, the gear 49 being engaged with the worm gear 46. The spring clutch is controlled through a paper-feeding lever 48 engaging with the carriage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small serial printer, and more particularly to a small serial printer.

Conventional serial printing printers place the type drum vertically relative to the printing paper, that is, with the rotation axis horizontal, and print by rotating, stopping, impacting, and shifting the type drum. The paper feed operation was performed after one line of printing was completed.

On the other hand, a serial printer is known in which a type drum is mounted around an axis perpendicular to the digit direction of the printing paper, and the type drum is conveyed in the digit direction of the printing paper.

This printer has a vertically arranged type drum with a type belt for printing symbols and a type belt for printing numbers, and since printing is performed by selectively operating one of them, the printing position is different for symbols and numbers. Complicated control mechanisms and operations were required to print these in the same row. The invention was made in view of the above circumstances, and it is possible to perform paper feeding operations reliably with an extremely simple structure. The purpose of this invention is to provide a small serial printer configured as follows.

In order to achieve the above object, the present invention provides a drive gear on the carriage that meshes with a drum gear integrated with the type drum, and a clutch gear on the frame side of the printer that meshes with the drum gear when the carriage comes to a predetermined position. A worm gear for supplying printing paper is provided which is interlocked with this clutch gear via a spring clutch, and a paper feeding roller is rotated via the gear for supplying printing paper which meshes with this worm gear to perform a paper feeding operation.

The spring clutch is controlled via a lever that engages with the carriage.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 schematically shows the overall structure of a small-sized serial printer according to the present invention. The small-sized serial printer according to the present invention is assembled on the basis of a housing-like frame l.

A motor 2 and a solenoid 3 that serves as a trigger when driving a control mechanism to be described later are attached to one end of the frame l. The output shaft 4 of the motor 2 extends outward beyond the left side plate 1a of the frame 1, and has a pulley 5 fixed to its tip. The rotating shaft 6 is parallel to the output shaft 4.
is rotatably supported on a frame 1, and a belt 8 is stretched between a pulley 7 fixed to the outer end of the rotating shaft 6 and transmits the rotation of the motor 2. Inside the pulley 7, a tacho-generator coil IO having a tacho-generator magnet 9 which rotates together with the rotary shaft 6 is attached to detect timing pulses representing the position of the type on the type drum 16.

As shown in FIG. 2, a worm gear 1 is installed in the middle of the rotating shaft 6
1 is fixed, and the worm gear 11 is attached to the frame l.
It is rotatably supported via a shaft 13b, and is always in mesh with a drum gear 13 which is integrated with the type drum 16. As shown in FIG. 3, a contact piece 14 for detecting a reset pulse signal is provided on a part of the carriage 12, and its tip engages with a protrusion 13a protruding from the side surface of the drum gear 13. I am in a position where I can do it.

The drum gear 13 is connected to a guide shaft 15.1 as shown in FIG.
5, and a type drum 16 is rotatably supported on the F side of the carriage 12 coaxially with the drum gear 13. The type drum 16 has a cylindrical base 16a as shown in FIG.

type bell) 16b for numbers and type belt 16 for symbols
c is wrapped, and the rear end side of each type belt is attached to the base 1.
It is exposed to the inside of the base through a through hole made in 6a. It also has a blank printed area for two characters.

A hammer unit 17 is arranged above the type tram 16. The hammer unit 17 consists of a hammer 18 for printing numbers located on the lower side and a hammer 19 for printing symbols located on the upper side.As shown in FIG. is rotatably supported by a support shaft 20. As is clear from FIG. 6, the number printing hammer 18 has an arm 18a extending above the type drum 16, and a printing roller 21 is attached to the lower surface of the tip of the arm 18a.
is rotatably supported on a shaft, fitted into the type drum 16, and facing the type bell (16b) for numbers. The tip of the other arm 18b of the hammer 18 is connected to a cam plate 2 having a linear cross section and extending horizontally between the arm 18b and the motor 2 along the rotation shaft 6.
The vertical portion 22a of the vertical portion 22a is located at a position where it comes into contact with a protrusion 23 protruding from the inside of the base.

The symbol printing hammer 19 is fitted into the type drum 16 by bending the tip of one arm 19a, and has an opening at the tip at a position below the roller 21 and facing the symbol type belt 16c. The roller 24 is rotatably supported. The tip of the other arm 19b is attached to a protrusion 25 located above the protrusion 23 of the vertical portion 22a of the cam plate 22.
It is placed in a position where it can be engaged with. Note that these protrusions 23 and 25 have a simple triangular cross section, and are configured so that the arms 18b and 19b can be mounted on them from either the left or right direction.

Further, on the outer edge of the horizontal portion 22b of the cam plate 22, a plurality of substantially triangular protrusions 26 with an upright wall on the hammer unit side in FIG. 6 are formed in a sawtooth shape. As shown in FIG. 3, these protrusions 26 are engaged with claws 32a at the tips of elastic arms 32 protruding from one end of the carriage 12.

Furthermore, an ink roller 27 is rotatably supported on the carriage 12 near the type drum 16, as shown in FIG. 1, and is always in contact with the type drum 16 to apply ink.

On the other hand, as shown in FIG. 7, the cam plate 22 is supported on a shaft 28 via a platen 22c protruding from its lower end.
It is set so that it can freely rotate within a certain angular range, and a spring (not shown) gives it the ability to rotate clockwise in FIG. 7.

The reference numeral 29 in FIG. 1 is a return spring, one end of which is fixed to one end of the carriage 12 as shown in FIG. It passes through the platen 30 along with a guide 31 having a groove 8, and is fixed to the other side plate 1a, giving the carriage 12 the habit of moving to the right in FIG. However, when the claw 32a of the carriage 12 engages with the upright wall side of the protrusion 26 of the cam plate 22 as shown in FIG. 3, the movement of the carriage is restricted.

As shown in FIG. 2, a drive gear 33 is always meshed with the drum gear 13, and the drive gear 33 is connected to a shaft 34.
It is rotatably supported on the shaft.

As shown in FIG. 3, one end of a control lever 35 is rotatably supported on the rotating shaft 34 below the drive gear 33, as shown in FIG. It is given the habit of turning in the middle counterclockwise direction. The tip 35a of the control lever 35 faces the side of the carriage 12 at a position where it can engage with rack teeth 37a of a rack plate 37 arranged parallel to the horizontal portion 22b of the cam plate 22. Further, the drum gear 13
The rack plate 37 can also engage with the rack teeth 37a.
is rotatably supported within a certain angle range via a shaft 38 of the right side plate 1b in FIG. The shaft passes through the outside of the right side plate 1b, passes under the platen 30, and is guided to the outside of the left side plate 1a, and protrudes outward from the side plate 1a on the same axis as the shaft 38. It is supported on the shaft. Also,
A rack plate lever 39 is integrally formed on the side plate 1b side of the rack plate 37 at a position beyond the shaft 38, and a spring 40 is stretched between the tip 39a and the upper end of the side plate 1b. The rack plate 37 as a whole is given the habit of rotating clockwise in FIG. A protrusion 39b provided above the tip of the rack plate lever 39 is in contact with the tip of the armature 41 of the solenoid 3.

On the other hand, printing paper P is guided toward the space between the platen 30 and the type drum 16 while being held down by a paper guide 42. At the lower right side of the platen 3° in FIG. 1, there is a clutch gear 4 that meshes with the drive gear 33 when the carriage 12 is on the right end side, as shown in FIG.
3 is rotatably supported on a shaft 44.

The clutch gear 43 has a boss portion 43 as shown in FIG.
A coil spring 45 constituting a spring clutch is wound around a, and one end 45a of the coil spring 45a is wound around a.
Half-eed (the same applies hereafter) is fixed to the worm 46 side, the other end 45b protrudes outward from the bottom of the PF worm 46, and is rotatably supported near the clutch gear 43 via a shaft 47. It is in a state where it can engage with the tip end 48a of the PF lever 48. The PF worm 46 is formed in a cylindrical shape, is fitted on the outside of the coil spring 45, and is rotatably supported on the shaft 44, as shown in FIG.

As shown in FIG. 9, the worm portion 46a of the PF worm 46 meshes with a PF gear 49, and this PF gear 49 is fixed to a shaft 51 that is integrated with a rubber roller 50 that sends out printing paper. A small-diameter pinch roller 52 is in contact with the lower side of the rubber roller 50, and the printing paper P is guided between them and sent in the -L direction by the rotation of the rubber roller 50 via the PF' roller 49.

On the other hand, as shown in FIG. 1, a portion of the right side plate 1b is provided with a plate spring 53 which is approximately U-shaped and bent into an L-shape.
is fixed, and the bent free end 5 of this leaf spring 53
3a and 53b are in positions where they are engaged with a protrusion 54 protruding from the right end of the cam plate 22.

Next, the operation of the printer according to the present invention configured as described above will be explained.

When the switch is turned on, the rotation of the motor 2 in FIG. 1 is caused by the pulley 5. Belt 8. It is transmitted to the drum gear 13 via the pulley 7, rotating shaft 6, and worm gear 11, and the type drum 16 integrated therewith is continuously rotated clockwise in FIG.

In this state, a printed character is selected and the armature 41 is pulled by energizing the solenoid 3, pushing the protrusion 39b of the rack plate lever 39, and the rack plate 37 is raised from the state shown in FIG. 4 to the state shown in FIG. However, when the rack teeth 37a and the drive gear 33 are in mesh with each other, the rack plate 37
Since the drum gear 13 is in a fixed state, the drum gear 13 moves forward against the tensile force of the return spring 29 due to its rotational force, and the type drum 16 moves to the left in FIG. 1 while rotating.
A movement is held.

At this time, since the hammer unit 17 integrated with the carriage 12 also moves, the tip of the arm 18b of the hammer 18 for printing numbers, for example, rides on the protrusion 23 of the cam plate 22, as shown in FIGS. 18 is rotated in the counterclockwise direction in FIG.
Printing is performed by pressing it to 0. At this time, if the surface of the pressed letters deviates even slightly from the printing paper P, dirt or ghosts will occur during printing.
It is best to place the platen 30 at a position where the extended surfaces of the platens touch each other.
Printing can be performed while making complete rolling contact with the selected characters of the type heald 16b in a protruding state. The tip of the arm 18b of the hammer 18 is a protrusion 23.
When you get over one of the hammer 18 and type bell) 16
b returns to its original state as shown in FIG. 11, and printing of one digit is completed. At this time, if the solenoid 3 is left on, the rack plate 37 and drum gear 13 will not come apart.
The gear ridge 12 continues to perform the next carry, and the next cam protrusion 23 prints the character next to the character that has just been printed. When printing other characters next time, disengage the rack plate 37 and drum gear 13 by turning off the solenoid 3, and return to the state shown in FIG. Tip 3
5a is engaged, resulting in the state shown in FIGS. 13 to 14. The drum gear 13 idles and the carry-up movement of the carriage 12 is stopped. At the same time, the claw 32 of the carriage 12
a is caught on the protrusion 26 of the cam plate 22, and the carriage 12 does not return to its original position even when the tensile force of the return spring 29 is applied, and the carriage 12 stops at that position.When the 0th order printing character is selected, the solenoid 3 is activated. It is turned on and performs the same operation as described in 1.

The information that informs the control circuit of the position of the character to be printed is the initial position signal generated by the contact between the protrusion 13a and the contact piece 14 shown in FIG. 3, and the character position signal generated by the tachogenerator magnet 9 and coil 10 shown in FIG. There is a signal, and based on these two signals, the control circuit controls solenoid 3.
When the armature 41 is turned on, the rack plate lever 3
9, and the rack plate 37 is moved to the first position with the shaft 38 as the center.
The rack plate 37 is rotated counterclockwise in the figure, and the rack plate 37 rises from the state shown in FIG. 4 to the state shown in FIG. 10. When the rack teeth 37a mesh with the drum gear 13 and the carriage 12 begins to move in the state shown in FIG. The control lever 35 does not engage with the rack 137a even when the power is turned off, and the carriage 12 does not stop until it reaches the state shown in FIG. 14 after printing one digit. That is, the role of the control lever 35 is to prevent the rack teeth 37a from disengaging from the drum gear 13 during printing, to ensure printing for one digit, and to prevent the carriage 12 from overrunning. .

Next, the selection operation between symbol digit printing and numerical digit printing will be explained.

When the carriage 12 is at the rightmost home position as shown in FIG. 1 at the start of printing, when the carriage is viewed from the back side, the drive gear 33 and clutch gear 43 are engaged with each other and rotate as shown in FIG. in a state.

In this state, one end 45b of the coil spring 45 is engaged with the tip 48a of the PF lever 48, and the coil spring 45 is in a relaxed state, so the rotation of the clutch gear 43 is not transmitted to the PF worm gear 46. When the carriage is at the home position, the printing solenoid 3 is energized for the first time, carrying is performed as described above, and printing is simultaneously performed. At this time, the projection of the cam plate 22 is moved as shown in FIG. There is only one upper protrusion 25 that engages with the symbol printing hammer 19, and there is no protrusion 23 on the lower side of the protrusion 25 so that it does not engage with the number printing hammer 18.

Therefore, the first print is always a symbol, and furthermore, during the digit lifting, the protrusion 12a of the carriage 12 engages with the other end 48b of the PF lever 48, and the PF lever 48 is rotated counterclockwise in FIG. One end 45b of 45 and PF lever 4
When the engagement with one end 48a of fl is released and the state shown by the chain line in FIG. 2 is reached, the coil spring 45 is wound around the boss 43a, and the PF worm 46 is rotated by this force. but,
Since the protruding portion 12a of the carriage immediately stops contacting the PF lever 48 and passes, the PF lever 48 immediately returns to its original position by the force of a spring (not shown), and the PF worm 46 rotates once, causing one end 48a to snap into place with the coil spring. 45, the coil spring 45 is loosened and the spring clutch is turned off. Therefore, the PF worm 46 rotates exactly one rotation, rotates the PF gear 49, rotates the rubber roller 50, and feeds the printing paper by half a pitch.

In this way, the previously printed symbol is raised to the same level as the next digit, allowing the symbol and digit to be printed without having to move up and down during printing, as is often the case with typewriters. Can be printed on the same line.

By the way, when printing is performed sequentially in this way and all the digits have been printed, carriage 1 is placed at the leftmost position in Figure 1.
2, as shown in FIG. 15, the claw 32a at the base of the arm 32 of the carriage 12 comes into contact with the protrusion 22d formed on the left end of the cam plate 22 toward the carriage, and a spring (not shown) comes into contact. The cam plate 22 is rotated counterclockwise as shown in FIG. 7 against the force. As a result, the state in which the protrusion 54 of the cam plate 22 is engaged with the bent portion 53a of the leaf spring 53 as shown in FIG. 16 changes, and the protrusion 54 engages with the protrusion 54 as shown in FIG. moves to the left in the figure, and the protrusion 54 is locked inside the bent portion 53a of the leaf spring 53, holding the cam plate 22 in that position. In this state, the arm 32 of the carriage 12 and the protrusion 26 of the cam plate 22 are disengaged, so the carriage 12 returns to the spring 26.
It is pulled back to the right end in FIG. 1 by the tensile force of 9.

In this pullback operation, the spring force of the return spring 29 is set to be stronger than the spring force of the spring 36 pressing the control lever 35 against the rack plate 37 in FIG. The one end 48d of the PF lever 48 is pulled back rapidly until the carriage 12
When the carriage 12 returns to the home position, the carriage 12 is rotated counterclockwise again in FIG.

Further, when the carriage 12 returns to the home position, the protrusion 12b at the right end of the carriage 12 hits the tip 53b of the leaf spring 53 as shown in FIG.
3a and the protrusion 54 are disengaged, the cam plate 22 is rotated clockwise in FIG. 7 by a spring (not shown) and returns to its original state.

In this way, one printing cycle is completed.

On the other hand, when returning the carriage 12 midway without printing over all digits, it is necessary to perform a slightly different operation from that described above. That is, the base 16 of the type drum 16
A protrusion 16e is provided on the inside of a as shown in FIG. 19,
The position of this protrusion 16e is set as a position where no printing is performed.

Then, when the roller 21 of the hammer 18 attempts to perform a printing operation by turning on the solenoid 3 at the position of the protrusion 16e, the rotation of the hammer 18 is blocked by the protrusion lee, and the arm 1
When the protrusion 8b and the protrusion 23 meet, the arm 18b is moved.Contrary to the above, the arm 18b does not move and the protrusion 23 escapes, so the cam plate 2
2, the cam plate 22 is rotated in the same manner as described above, and as shown in FIG.
The carriage 12 returns to the home position and one printing cycle is completed.

Further, when only paper feeding is performed without printing, by turning on the solenoid twice for the protrusion 16e in the type drum 16, the paper is fed by l pitch and the carriage returns to the home position.

In addition, in the above-mentioned embodiment, if the type is divided in the circumferential direction of the type drum 16, the number of teeth of the drum gear 13 is the same number of 1 to 1, but the number of teeth is an integral multiple of the number of divisions of the type drum. But that's fine.

Furthermore, in the above embodiment, the number printing belt 1
6b and the symbol printing belt 16c are separate parts, but they may be wrapped as one body.Furthermore, the number of printing belts can be increased to, for example, three rows, and the ink rollers 27 can be used to print the two colors of red and black vertically. It is also possible to make it possible to perform two-pack medium-sized characters by placing the two-packs in the same position.

As is clear from the above description, according to the present invention, the carriage is provided with a drive gear that meshes with the drum gear, and the frame side of the printer is provided with a clutch gear that meshes with the carriage when it comes to a predetermined position. The structure is such that a worm gear for supplying printing paper is interlocked with a gear via a spring clutch, and the paper feed roller is rotated via a gear for supplying printing paper that meshes with the worm gear. Despite its simple structure, paper can be fed reliably.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention, in which Fig. 1 is a perspective view illustrating the overall structure, Fig. 2 is a bottom view illustrating a group of gears attached to the back side of the wheel ridge, and Fig. 3 FIG. 4 is a bottom view of the carriage, FIG.
The figure is a cross-sectional plan view of the type drum, FIG. 6 is a perspective view showing the interlocking relationship between the printing hammer and the cam member, FIG. 7 is a plan view illustrating the return movement of the carriage, and FIG. 8 is a spring clutch. FIG. 9 is a side view explaining the paper feeding mechanism, FIG. 1θ is a side view explaining the operation of the carriage drive control mechanism, and FIGS. 11 and 12 respectively show the printing operation of the hammer. Explanatory drawings, FIGS. 13 and 14 are explanatory views showing the interlocking relationship between the printing paper supply lever, the drum gear, and the rack plate that is a control member, and FIG. 15 is a side view of the main parts illustrating the carriage return operation. , FIGS. 16 to 19 are explanatory diagrams showing the control operation of the cam member during the digit return operation, respectively. 2...Motor 3...Solenoid 6...
Rotating shaft 11... Worm gear 12... Carriage 13... Drum gear 16... Type drum tea... Base 16b... Type belt for numbers 18c... Type belt for symbols 18... Numbers Printing hammer 18...- Symbol printing hammer 22...Cam plate 23.25...Protrusion 33
...Drive gear 37...Rack plate 39...
Rack plate lever 43...Clutch gear, gear 45...
Coil spring 48...Paper feed worm 48...
Paper feed lever 49... Paper feed gear 50... Rubber roller Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] A small serial printer is equipped with a type drum that rotates around an axis perpendicular to the digit direction of printing paper, and a carriage that conveys the type drum in the direction of the printing digit. numbers on the side,
A type drum having a plurality of type belts such as symbols etc. on -LF, one end facing inside the base of the type drum, and the other end facing at a position outside the type drum where it contacts a cam member that engages with the type belt. a hammer that is rotatable when the carriage is in a predetermined position; a drive gear that meshes with the drum gear; a clutch gear that is installed on the frame side of the printer and that meshes with this when the carriage comes to a predetermined position; and a worm gear for supplying printing paper that is interlocked with each other via a spring clutch, and a paper feeding roller is rotated via the gear for supplying printing paper that meshes with the worm gear to perform a paper feeding operation and control the spring clutch. A small serial printer characterized in that the printing is performed via a lever that engages with a carriage.