JPS61167584A - Printer - Google Patents

Abstract

PURPOSE:To eliminate the necessity of providing a paper feed mechanism by controlling through the type selection operation of a type selection mechanism driven by a one-direction rotating motor and the printing and line feed operation of a printing/line feed mechanism. CONSTITUTION:A driving force of a DC motor 4 is transmitted to a main gear 8, and then to a drive-side pulley 1 through a spring clutch. A printing and line feed gear 9 is intermeshed with the main gear 8 and is actuated by an electromagnetic solenoid 18 through a selection lever 17. Paper 16 is fed from under a paper feed roller 14 and a guide plate 15 and guided to a spot near the outside of a type belt 3. Paper feed is set by the type selection operation and paper feed is reset by the printing and line feed operation, thus feeding paper by repeating only type selection operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to printers, and more particularly to serial printers.

(Background of the Invention) Recent calculators have become more multi-functional and sophisticated, as well as smaller and lighter.There is a desire for calculators with printers that can save calculation results as printed data to be smaller and lighter as well. Therefore, the built-in printer is small and lightweight, and a roll made of easily available and inexpensive 38 m wide or 58 cm wide plain paper is suitable for a printer built into an electronic device with low power consumption. Since paper can be used and the printed data is clear, a boat-shaped printing type is desired, and it is also expected to require fewer driving sources (and be inexpensive).

[Summary of the invention]

The present invention includes a type selection mechanism driven by a motor that always rotates in one direction, a printing/carrying mechanism, and a paper feeding mechanism, and the type selection operation and the printing/carrying operation perform the following operations.
The feature is that the paper feeding operation is controlled.

[Effect]

In the present invention, the paper feed mechanism is set by the type selection operation, and the set paper feed mechanism is further reset by the type/carry operation. In other words, the paper feed mechanism is constantly set and reset by character selection, printing, and carrying.

Then, only the printing character selection operation is performed for a certain period of time, and I″n
If; l-L4 + trh4 乍島 く j 嬬 h h stabbing ＾ Bait 4 ≠ hmh 之礍礍 .

(Embodiment 1 of the Invention Next, a serial printer according to an embodiment of the invention will be explained in detail with reference to the drawings. First, the general configuration of the printer will be described.

[1. Schematic Configuration] FIG. 1 is a schematic diagram of the printer. A driving pulley 1 and a driven pulley 2 are arranged at a predetermined interval,
An endless type belt 3 is passed between them. 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 side boot 1) via a spring clutch (not shown).
1 and main gear 8.
The printing/carrying gear 9 can be engaged with the printing/carrying gear 9.

One end of a print/carry shaft 10 is connected to the print/finger lift gear 9, and this print/carry shaft 10. is the drive side boo Q1
and the driven side boob IJ 2, and extends parallel to the type belt 3. A hammer holder 11 is attached to the print/carry shaft 10 so as to be slidable in the axial direction, and a hammer and a carry cam are built in and supported therein as will be described later. A holder return spring 1 is attached to the hammer holder 11.
One end of the spring 12 is connected to the other end of the spring 12, and the other end of the spring 12 is fixed to the base. Therefore, the hammer holder 11 is always elastically biased toward the home position side near the driven side boob I72 by the tensile force of the holder return spring 12.

Near the print/carry shaft 10, a rack 13 is installed parallel to it.
are arranged so that the carry cam built in the hammer holder 11 and the rack teeth of the rack 13 can mesh with each other as described later. A paper feed roller 14 and a flat guide plate 15 that also serves as a platen are disposed behind the rack 13, and the paper 16 is sent out from below the paper feed roller 14 and the guide plate 15 to a position near the outside of the type belt 3. will be guided to. A lever 17 is operated by an electromagnetic solenoid 18 to switch and transmit the rotational force of the main gear 8 from the drive pulley 1 to the print/carry gear 9 at a predetermined timing. Reference numeral 20 denotes an ink roller that comes into contact with the type portion on the outer peripheral side of the type belt 3 to apply ink to the type surface.

The series of basic operations of this printer are type selection operation,
It consists of a printing/carrying operation and a hammer holder return/paper feeding operation, and by sequentially repeating each of these operations, many lines are printed. Each of the above-mentioned operations and the mechanisms related thereto will be explained in sequence, but first the configuration of the type belt 3 will be explained.

[2. Structure of Type Belt] As shown in Fig. 3, the type belt 3 has an endless shape, and a large number of type portions 21 are individually provided along the circumferential direction at a predetermined pitch on the outer circumferential side, On the circumferential side, a large number of belt teeth 22 are provided at a predetermined pitch along the circumferential direction.0Individual character parts 21In other words, both characters are provided at the same pitch, and the character parts 21 (belt tooth parts 22) and the adjacent type part 21 (belt tooth part 22) is a thin connecting part 23.
are connected to each other. These type portions 21. Belt tooth portion 22. The connecting portion 23 is made of, for example, synthetic rubber or synthetic resin with a low degree of polymerization, and the type belt 3 as a whole has appropriate flexibility, stretchability, and elasticity.

As shown in FIG.
), a number group (FC), and a number group (FG). The symbol group (MG) has r+J as shown in Figure 14.
, r-J, rXJ, etc. are provided. Each number group (FG) is from “0” to “9”.
There are 10 types of numeric characters in the same arrangement. Therefore, one type group has a total of 33 characters in the type part 21.
There are 66 type parts 21 in the entire type belt. In this way, a group of frequently used numbers (F
By providing a plurality of G), it is possible to reduce the loss time for character selection as much as possible.

As explained earlier, the type belt 3 is passed between the driving pulley 1 and the driven pulley 2, and the belt teeth 22 provided on the inner circumferential side of the type belt 3 are connected to the driving side boolean I71 and the driven side pulley 2. They mesh with the pulley teeth 24 (see Figure 2) of the side pulleys 2 to ensure that the type belt 3 is securely moved without slipping.
rotation is performed. As shown in FIG. 1, the driving pulley 1 is rotated counterclockwise in the figure, and the type belt 3 is rotated in the direction of the arrow, and the driven pulley 2 and the driving pulley 1 on the side facing the paper 16 are rotated. The tension side is between.

For this reason, the side of the type belt 3 facing the paper 16 does not sag and does not swing significantly along the feeding direction of the paper 16 even if it vibrates a little. Therefore, the accuracy of the printing position when printing is improved. Moreover, as printers become smaller, the distance between the type belt 3 and the paper 16 becomes narrower (even if the distance between the type belt 3 and the paper 16 becomes narrower, the type part 21 will not come into contact with the paper 16 unexpectedly.Next, the type selection mechanism will be explained.

[3. Type Selection Mechanism] First, the drive mechanism for the type belt 3 will be explained. As described above, the driving force of the motor 4 is transmitted to the main gear 8 via the worm 5, the first idle gear 6, and the second idle gear 7. Further, in order to transmit the driving force of the main gear 8 to the drive side boolean I71 or to interrupt the drive transmission, a known spring clutch (not shown) is provided between the main gear 8 and the drive side pulley 1. is mediated.

A code disk 25 (see FIG. 2) is disposed coaxially below the main gear 8, and eventually rotates synchronously with the drive pulley 1. The main gear 8 has a bevel gear shape and can mesh with the printing/carrying gear 9.

The spring clutch is in a state where power can be transmitted (ON)
The power is transmitted from the main gear 8 to the drive pulley 1, or the spring clutch is in a state where power cannot be transmitted! (OFF) to stop the rotation of the drive pulley 1, and instead switch the power transmission such as transmitting the driving force of the main gear 8 to the printing/carry gear 9 and rotating it. This is the lever 17. When the spring clutch is turned on by operating the selection lever 17 and the driving pulley 1 is rotated in the direction of arrow B as shown in FIG. 1, the type belt 3 is transferred in the direction of arrow A accordingly.

Although not shown, a conductive pattern having a predetermined pattern shape is formed on the lower surface of the code disk 25 to detect the rotation angle of the driving pulley 1, in other words, the amount of movement of the type belt 3. Furthermore, a plurality of contact pieces including a set contact piece, a reset contact piece, and a common contact piece are in elastic contact with this conductive pattern. These contact pieces are connected to a control section (not shown) by lead wires.

A code plate tooth part 26 is provided on the upper part of the code disk 25, and a spur gear part 28 of the sensor gear 27 meshes with the code plate tooth part 26. As shown in FIG. 4, a disk portion 29 having a diameter equal to the tip circle diameter of the spur gear portion 28 is provided on the spur gear portion 28.
A trigger groove portion 30 is formed at one location on the circumference from the spur gear portion 28 to the disk portion 29. Spur gear part 2
A cam disk portion 32 having a cam protrusion 31 at one location on the outer periphery is provided below 8 .

The number of teeth of the code plate tooth portion 26 on the code disk 25 is equal to the number of teeth of the pulley tooth portion 24 on the driving pulley l. Further, the number of teeth of the spur gear portion 28 in the sensor gear 27 is equal to the total number of characters in the character group 1&IL (symbol group, 10 digit group, 10 digit group) in the character belt 3. Therefore, while the sensor gear 27 makes one revolution, the type belt 3 makes exactly half a revolution.

A control gear 33 is arranged next to the sensor gear 27, and its shape will be explained with reference to FIG. 5. A single gear part 35 having one tooth part 34 in the circumferential direction is provided at the top of the control gear 33, and a fitting hole 3 is provided in the center of the gear part 35.
6 is drilled.

- A spur gear part 38 having a toothless part 37 near the part facing the tooth part 34 is provided below the gear part 35, and this spur gear part 38 is connected to the spur gear part 28 of the sensor gear 27. It is designed to fit together.

A locking portion 40 is provided below the spur gear portion 38 and has one locking groove ’39 on the outer periphery on the side substantially opposite to the toothless portion 37 . A paper feed cam portion 41 having a slightly larger diameter than the locking portion 40 is provided below the locking portion 40, and two spiral tooth portions 42a and 42b are formed on the outer periphery of the cam portion so as to face each other in a crossed state. ing. As shown in the same figure (d), an incisal tooth portion 42c is provided between the spiral tooth portions 42a and 42b,
Further, as shown in FIG. 4(E), a spring hook pin 41a is provided protruding from the top surface of the paper feed cam portion 41. These-gear parts 35. Spur gear part 38. The control gear 33, which includes the locking portion 40 and the paper feed cam portion 41, is integrally formed by molding synthetic resin. - A reset plate 43 is arranged above the control gear 33, and by press-fitting a shaft 44 hanging from the center of the lower surface of the reset plate 43 into the fitting hole 36 of the control gear 33, the reset plate 43 rotates together with the control gear 33. do.

On the upper surface of the reset plate 43, there is one protrusion 4 near the outer periphery.
5 is provided.

The locking groove 39 of the locking portion 40 of the control gear 33 is configured such that the claw portion 47 of the rotating lever 46 can be fitted into it. A protruding portion 48 is provided, and its tip end is always in elastic contact with the cam disc portion 32 of the sensor gear 27, as shown in FIG.

As shown in FIG. 2, a spring hook pin 46a is protruding from the lower surface of the rotating lever 46, and a tension spring 78 is stretched between the spring hook of the paper feed cam portion 41 and the pin 41a. . Due to the tensile force of this tension spring 78, the control gear 33
and the rotation lever 46 are each urged to rotate in a predetermined direction.

In order to select type, it is first necessary to detect the reference position of the type belt 3. In this embodiment, sensor gear 2
Immediately after the rotary lever 46 is rotated by its cam protrusion 31 as the character 7 rotates, in other words, immediately after the claw portion 47 of the rotary lever 46 disengages from the locking groove 39 of the control gear 33, the type belt “6” in the second group of numbers (FG) in 3
A hammer with the type part 21 in the home position (described later)
The position corresponding to this is configured to be the reference position of the type belt 3. In this way, when the type belt 3 is at the reference position, the distance of each type part 21 from the type part 21 corresponding to the hammer is known in advance, so after the reference position is detected, the amount of movement of the type belt 3, in other words, can be determined. For example, by counting the rotation angle of the driving pulley 1 by pulse signals from the code disk 25, the type belt 3 can be rotated to a position where the type part 21, which is commanded by the control section, corresponds to the hammer. In addition, since the position of the hammer changes sequentially due to carry, we will explain the 0th order printing/carry mechanism in which the desired type is selected by counting the pulse signal mentioned above while taking into consideration the amount of movement of the hammer. do.

[4, Printing/Carry Mechanism] A hammer holder 11 is held on the printing/carry shaft 10 so as to be slidable in the axial direction thereof.
It has a bark shape as shown in the figure.

That is, insertion holes 49 and 49 through which the printing/carrying shaft 10 can freely rotate are formed at predetermined positions on both side plates, and a hammer holder W part 50 is inserted horizontally from the rear to the front on the inner side of the half. It is extending. The spring hook is pin 5 at the rear of one side plate.
1 is provided protrudingly, and a long groove 52 is horizontally cut in front of it with the spring hook facing the direction of the pin 51. Partition wall portions 53 are suspended from both sides of the front of the hammer holder 11, and an ejection opening 54 having a size through which one type portion 21 can be ejected is provided between the partition wall portions 53.

A hammer 55 is placed on the hammer placement portion 50 such that an extrusion portion 56 provided at the tip thereof faces the protrusion opening 54 . A convex portion 57 is formed on the upper surface of the rear end of the hammer 55.
is provided in a protruding manner and is slidably fitted into a guide groove 58 formed on the upper surface of the hammer holder 11. Hammer 55
A spring hook pin 59 is protruded from one side surface of the hammer holder 11, and this pin 59 protrudes outward from the long groove 52 of the hammer holder 11. A tension spring (not shown) is passed between the pin 59 and the spring hook of the hammer holder 11, and the tension force of the spring causes the hammer 55 to move away from the type belt 3 (backwards). Elastically biased. Note that the type belt 3 is configured to pass inside the partition wall portion 53 of the hammer holder 11.

Below the hammer mounting portion 50 of the hammer holder 11, a carry cam 60 is spline-coupled to the printing/carry shaft 10.
is built-in. This cam 60 includes a hammer drive portion 61 extending in one direction from the center toward the outer periphery, and a hammer drive portion 61 extending in one direction from the center to the outer periphery.
It is composed of a carry-up cam part 63 having a protruding strip 62, and an elliptical rack rotation part 64 for returning the rack. The hammer driving section 61 comes into contact with a receiving section 65 provided on the hammer 55 by rotation.

FIG. 8 is a developed view of the cam surface of the carry cam portion 63. The protrusion 62 includes a circumferentially extending circumferential protrusion 62a provided over about half of the circumferential direction, and a spiral protrusion 62a extending helically and provided over the remaining half of the circumferential direction. These protrusions 62a
, 62b are continuous. This protrusion 62 corresponds to the rack 13
Rack teeth 66 (second
As shown in FIG. 9, the rack rotation part 64, which is designed to mesh with the rack rotation part 64 (see figure), hits a return lever part 67 provided at the end of the like 13 (on the home position side) as shown in FIG. It looks like this.

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 66 mesh with the protrusions 62 of the carry cam 60.
Or the engagement may be released. At the end of the rack 13 on the side where the return lever part 67 is not provided, a rotation stopper claw part 6B and an example cutout part 69 are formed with a rotation stopper claw part 68 and a tilting notch part 69. is adapted to engage with a protrusion 45 of the reset plate 43, as shown in FIGS. 10 and 11.

As shown in FIG. 2, an elliptical lever pushing cam portion 70 is provided on one side of the printing/carrying gear 9, and this is always in elastic contact with the tip surface of the vertical wall portion 72 of the gear clutch lever 71. has been done. Therefore, when the print/carry gear 9 (lever pushing cam portion 70) rotates once in the direction of arrow C, the gear clutch lever 71 reciprocates once in the direction of arrow C.

Further, the gear clutch lever 71 is provided with a reset portion 73, which comes into contact with the protrusion 45 of the reset plate 43, as shown in FIG.

When the hammer holder 11 is pulled by the holder return spring 12 (see FIG. 1) and is at the home position, the reference position of the type belt 3 is detected as described in the previous section [Print character selection mechanism]. At this time, rack 1
3 has fallen down as shown in Figure 9 (a), and the rack teeth 6
6 does not engage with the protrusion 62 of the carry cam 60,
Furthermore, the set plate 43 is biased to rotate in the direction of arrow E in FIG. 10 by a spring (not shown) attached to the control gear 33, but as shown in FIG. When the reset plate 43 falls down, its rotation stopper claw 68 locks the protrusion 45 of the reset plate 43, so that the reset plate 43 and the control gear 33 connected thereto are prevented from rotating.

Furthermore, when the reference position is being detected, the cutout m portion 37 of the control gear 33 faces the spur gear portion 28 of the sensor gear 27, as shown in FIG. 6(a), and the two do not mesh. ing. Further, at this time, the cam surface abutting portion 48 of the rotary lever 46 is in contact with the cam bottom 74 of the cam disc portion 32 of the sensor gear 27, so that the claw portion 47 of the rotary lever 46 is in the locking groove of the control gear 33. I'm getting into 39.

The sensor gear 27 continues to rotate in the direction of arrow F, and the sixth
As shown in Figure (B), the cam surface contact portion 4 of the rotating lever 46
8 rides on the cam protrusion 31, the rotating lever 46 rotates in the direction of arrow G, and the claw portion 4 of the rotating lever 46 rotates in the direction of arrow G.
7 comes out from the locking groove 39 of the control gear 33. However, the first
As shown in FIG. 0(A), since the rotation is stopped by the rotation stopper claw 68, the control gear 33 and the reset plate 43 do not rotate and remain as they are. The reference position of the type belt 3 is set immediately after the sensor gear 27 rotates and the cam surface contact portion 48 of the rotary lever 46 falls from the cam protrusion 31, so after the reference position is detected, the type is selected. will be done. Regarding type selection, please refer to the previous section [
Since it was explained in the section ``Print Selection Mechanism'', the explanation will be omitted here.

Due to the depression of the cam surface abutting portion 48 described above, the rotating lever 46 rotates in the direction opposite to the direction of arrow G, and the claw portion 47 enters the locking groove 39 of the control gear 33 again.

Once the type is selected at the bottom line (home position), the printing operation continues.

FIGS. 13(A) and 13(B) are diagrams for explaining the printing operation, with FIG. 13(A) showing the state before printing and FIG. 13(B) showing the state after printing, respectively.

In the state before printing, as shown in FIG. 13(a), the hammer 55 is pulled backward by the tension spring.
It is positioned by a stopper (not shown). Therefore, the type belt 3 (type portion 21) is located between the partition wall portion 53 of the hammer holder 11 and the extrusion portion 56 of the hammer 55,
The extrusion part 56 is slightly out of place. Also, the hammer drive section 61
is directed downward and is not in contact with the receiving portion 65 of the hammer 55.

The print/carry width 10 is one rotation in the direction of arrow C due to the drive transmission from the main gear 8, but the rack 1 rotates in the previous half-circle.
The return operation and print operation of No. 3 are carried out continuously during the subsequent half cycle. That is, when the print/carry width 10 rotates in the direction of arrow C, the carry cam 60 spline-coupled thereto also rotates together. Figure 9 (a).

As shown in (b), at the beginning of the rotation of the carry cam 60 in the direction of the arrow H, the rack rotating section 64 kicks up the return lever part 67 in the direction of the arrow 1, thereby the rack 13 returns to its original position. As shown in Figure (b), the rack teeth 66 and the protrusions 62 mesh with each other. Since the circumferential protrusion 62a (see Fig. 8) meshes with the rack teeth 66 in this first half-circle, there is no movement of the carry cam 6° (hammer holder 11, hammer 55, etc.) and the It's only half a turn.

Halfway around this carry cam 60, the hammer drive section 61
As shown in Figure (B), the hammer 55 comes into contact with the receiving part 65,
As the hammer drive unit 61 continues to rotate, the hammer 55 is pushed forward against the elasticity of the tension spring.0 The selected character portion 21 facing the paper 16 is pushed out of the hammer 55 into its ejection opening 54. (See FIG. 7) is projected forward and pressed against the paper 16 to perform desired printing.

Note that, as shown in FIG. 7, since the partition wall portions 53 are provided on both sides of the projection opening 54, unnecessary printing such as side printing is not performed.

As the carry cam 60 rotates, the hammer drive unit 61 moves upward from the horizontal position as shown in FIG. Stay away from 3. During this reciprocating movement of the hammer 55, the hammer rest 50. Convex portion 5
7 and the guide groove 58 and the spring hook engages the pin 59 and the long groove 52, the hammer 55 is properly guided.

Subsequently, when the carry cam 6 (>) rotates, the spiral protrusion 62b (see FIG. 8) meshes with the rack teeth 66, and as the carry cam 6 rotates, the hammer holder 11. The carry cam 60 and the like move toward the upper digit (to the left in FIG. 1) by an amount equivalent to one digit to carry up.

Although the explanation will be complicated, when the rack 13 returns as described above, the rotation stopper claw 68 of the rack 13 separates from the protrusion 45 as shown in FIG. 10(B). Therefore, only the rotary lever 46 prevents the control gear 33 and the reset plate 43 from rotating. When the cam surface contact portion 48 is disengaged from the claw portion 47 and the locking groove 39 by the cam protrusion 31 as shown in FIG. 6(B), the control gear 33 is slightly rotated in the direction of arrow J by the biasing force of the tension spring 78, and the tooth portion 34 of the gear portion 35 comes into sliding contact with the outer peripheral surface of the disc portion 29 of the sensor gear 27. The state shown in FIG. 6(C) is called the paper feed set state. At this time, the projection 45 of the reset plate 43 is in the position shown in FIG. 12(B).

Here, the trigger groove part 34 of the sensor gear 27 is in a position where it meshes with the single tooth part 34 of the control gear 33 when the 30th printed part 21 comes after the cam protrusion 31 pushes out the cam surface contact part 48. It is designed to be. Therefore, after setting the paper feed, if printing is performed even once during the transfer of the type belt 3 for 30 characters, the gear clutch lever 11 is reset by forward movement in the D direction as shown in FIG. 12 (b). Board 4
3 rotates in the direction of the arrow, and the protrusion 45 is pushed back to the position shown in FIG. ] Since the reset plate 43 is pushed back, the rotating lever 46 is moved as shown in FIG. 6(d).
The pawl portion 47 reenters the locking groove 39 of the control gear 33, and even when the trigger groove portion 30 of the sensor gear 27 passes under the tooth portion 34, they do not engage, and no paper feeding operation is performed.

In this way, type selection, printing operation, 2-digit increment operation.

The paper feed setting operation and its reset operation are sequentially repeated to print one line.

Next, the hammer holder return/paper feeding mechanism will be explained.

[5. Hammer holder return/paper feeding mechanism] When printing for one line is completed as described above, the hammer holder 11 is returned to the home position, and the paper is fed by an amount corresponding to a portion of the paper to print the next line. We need to be prepared.

The above system as shown in Figure 2? The spiral tooth portion 42 of the paper feed cam portion 41 in the No. 11 gear 33 is adapted to mesh with the intermediate gear 75. The connecting shaft 76 of this intermediate gear 75
is press-fitted into the center shaft hole 77 of the paper feed roller 14 and rotated together with the paper feed roller 14.

If no printing operation is performed even once during the transfer of the type belt 3 for 30 characters after the above-mentioned paper feed is set, printing of that line is deemed to have been completed. Therefore, when the 30th type is set after the 30th printing, Figure 6 (E)
As shown in FIG.
The single tooth portion 34 of the gear 33 is fitted. Subsequently, with the rotation of the sensor gear 27, the spur gear portion 26 of the sensor tooth i27 and the spur gear portion 26 of the control gear 33 are engaged with each other, and the control gear 33 and the reset plate 43 are rotated once.

Before the control gear 33 rotates, that is, in a state other than paper feeding operation, the intermediate gear 75 faces the toothless portion 42c of the paper feeding cam portion 41, as shown in FIG. Therefore, at times other than the paper feeding operation, the intermediate gear 75 and the paper feeding roller 14 can rotate freely, the paper 16 can be attached and detached without any problem, and the control gear 33 does not become misaligned.

If the intermediate gear 75 is always in mesh with the spiral tooth portion 42 of the control gear 33, the following problems will occur.

That is, the paper 16 is attached to the paper feed roller 14,
When the paper 16 is removed from the paper feed roller 14 or when the paper 16 attached to the paper feed roller 14 is pulled out by a predetermined length, the control gear 33 is rotated in the rotational direction via the paper feed roller 14 and the intermediate gear 75. Vertical load is applied. This load makes the operation associated with the spring control gear 33 unstable. Furthermore, since the paper feed roller 14 is braked, it is difficult to handle the paper 16.

As described above, the toothless portion 42C of the spiral toothed portion 42 of the paper feed cam portion 41 is in a non-meshing state with the intermediate gear 75. Tabait 1G small dog shashayasai Imabait:!
Even if the hn-ra 14 or the intermediate gear 75 rotates, the control gear 33
Stability of operation can be achieved without shifting the position.

The toothless portion 42C is designed to be large enough to accommodate the teeth of the intermediate gear 75, and the opening angle θ(
(see Fig. 15) is approximately 60 degrees.

The sensor gear 27 and the control gear 33 mesh to form the control gear 3.
3 rotates in the direction of arrow J as shown in FIG. 15, the spiral tooth portion 42a of the control gear 33 meshes with the tooth portion of the intermediate gear 75. The following shape is adopted to ensure smooth engagement. That is, the end edge 42d of the helical tooth portion 42a that first meshes with the intermediate gear 75 does not extend radially from the root of the helical tooth portion 42a toward the tip of the tooth, but rather the end edge 42d of the helical tooth portion 42a that first meshes with the intermediate gear 75 does not extend radially from the root of the helical tooth portion 42a toward the tip of the tooth. The end edge 42d is inclined so as to widen slightly when viewed from a plane so that the base portion engages with the intermediate gear 75 and then the tooth tip portion thereof engages. Furthermore, this edge 42d is shown in FIG.
It is shaped into a tapered shape as shown in the figure.

On the other hand, the lower tooth portion of the intermediate gear 75 is provided with an inclined portion 75a, such as a rounded or chamfered portion, as shown in FIG.

The rotational force of the intermediate gear 75 is transmitted to the paper feed roller 14,
By its rotation, the paper 16 is fed by an amount corresponding to a portion. During this paper feeding operation, when the protrusion 45 of the reset plate 43 has rotated about half a turn as shown in FIG. 12(C), the protrusion 45 is attached to the rack 13 as shown in FIG. 11(A). It fits under the tapered example notch 70.

When the reset plate 43 further rotates in the direction of the arrow E, the side of the rack 13 opposite to the rack teeth 66 is pushed up by the insertion of the projections 45, and the rack 13 is thrown down in the direction of the arrow. When the rack 13 is brought down in this way, the engagement between the rack teeth 66 and the protrusion 62 of the carry cam 60 is disengaged.
The hammer holder 11 containing the hammer 55 and paper feed cam 60 is returned to the home position by the tensile force of the holder return spring 12.

When the control gear 33 rotates once, the claw portion 47 enters the locking groove 39 of the control gear 33 as shown in FIG. 6, the toothless portion 37 faces the sensor gear 27, and as shown in FIG. The protrusion 45 of the reset plate 43 is engaged with the rotation stopper 68 of the fallen rack 13, and is ready for printing the next row.

Figure 14 is a diagram showing the arrangement of printed characters for each digit, and the 30 characters of printed characters after the paper feed is set and before the paper feed operation starts include all types of characters in every digit. There is. Therefore, if the printing operation is not performed while the type belt 3 is being moved for 30 characters after being set, it means that the printing of that line has been completed, and the next digit return and paper feeding operation is started.

In this embodiment, the paper feed roller 14 and the intermediate gear 75 are separated, but it is also possible to integrate them.

(Effects of the Invention) As described above, the present invention sets the paper feed by the type selection operation, resets the paper feed by the print/carry operation, and further performs the paper feed operation by repeating only the type selection operation. I made it.

Therefore, since there is no need to provide a separate mechanism for paper feeding, the structure is simplified, the number of parts can be reduced, and the printer can be made smaller and lower in price.

[Brief explanation of the drawing]

The drawings are all for explaining a printer according to an embodiment of the present invention. Fig. 1 is a schematic configuration diagram of the printer, Fig. 2 is an exploded perspective view of essential parts of the invention, and Fig. 3 is a plan view of a type belt. An explanatory diagram as seen from above, Fig. 4 is a bottom view of the sensor gear, Fig. 51!
I is a diagram for explaining the control gear, and (A) is a plan view of the -gear section, (B) is a plan view of the spur gear section, and (C) is a plan view of the locking section. The same figure (d) and the same figure (e) are a plan view and a side view of the paper feed cam part, the same figure (f) is a partially enlarged side view of the spiral tooth part, and FIGS. 6 (a) and (b). ,(c)
. (d) and (e) are explanatory diagrams showing the engagement relationship between the sensor gear, control gear, and rotating lever in each state, Figure 7 is a perspective view of the hammer holder, hammer, and carry cam, and Figure 8 is the girder. A developed view of the cam surface of the raising cam part, Figures 9 (A) and (B) are explanatory diagrams for explaining the rack return operation, and Figure 10 (A).
(B) is an explanatory diagram for explaining the rotation stopping operation of the reset plate by the rack, No. 111! I (a) and (b) are explanatory diagrams for explaining the rack tilting operation, Figure 12 (a)
, (b), (c) are explanatory diagrams for explaining the engagement relationship between the gear clutch lever and the reset plate, and Fig. 13 (a), (
b) is a cross-sectional view of the main parts to explain the printing operation, Fig. 14 is an explanatory drawing showing the arrangement of letters for each digit, and Fig. 15 is an explanatory drawing showing the facing state of the paper feed cam part and the intermediate gear. It is. 14...Paper feed roller, 16...Paper, 33...
...Control gear, 41...Paper feed cam section, 42B,
42b...Spiral tooth part, 42c...Toothless part, 7
5... Intermediate gear. Figure 1, figure 3, figure 170 t'80 figure 22, Q, figure 4, figure 7? 5 years old 60 years old 2o figure (a)
(mouth 9 years old 120 1'14 figure 10 I 3E21 (A) 715 days

Claims (1)

[Claims] Equipped with a type selection mechanism driven by a motor that always rotates in one direction, a printing/carrying mechanism, and a paper feeding mechanism,
A printer characterized in that a paper feeding operation is controlled by a type selection operation and a printing/carrying operation.