JPS622992B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a type-type serial printer using an endless belt type type carrier, and particularly to a serial printer characterized by paper feeding.

[Conventional technology]

Recently, calculators have become more multi-functional and high-end.
It is desired that calculators with printers, which are smaller and lighter and can save calculation results as printed data, also be smaller and lighter. Therefore, it is desired that the built-in printer be small, lightweight, and consume low power. In addition, printers built into electronic devices used in general households can use easily available and inexpensive roll paper made of 38 mm or 58 mm wide plain paper, and the printed data is clear. For this reason, it is desirable to use a matrix printing method, and it is also expected to be inexpensive as it requires fewer driving sources.

By the way, when paper is fed using roll paper as described above, regardless of whether it is a line printer or a serial printer, complicated driving force transmission such as gear means formed in multiple stages from the motor for driving the type belt is required. It has been common practice to feed the paper by driving the paper feed roller via a mechanism or by providing a separate motor to drive only the paper feed roller.

[Problem that the invention seeks to solve]

In other words, in the case of conventional printers such as those mentioned above, a motor for paper feeding was provided separately from the type belt, and a complicated transmission mechanism as mentioned above was provided, which increased the weight and cost. There was a problem.

This invention was made in view of the above-mentioned state of the prior art, and its purpose is to provide a motor for paper feeding,
To provide a printer that does not require a complicated transmission mechanism, is inexpensive, and has a paper feeding mechanism with a simple configuration.

[Means for solving problems]

In order to achieve the above object, the present invention is configured such that paper feeding is performed in conjunction with the return of the printing hammer to its home position. Specifically, the present invention comprises an endless belt-shaped type carrier that rotates in a predetermined direction, a protruding pressing member provided at a predetermined position of the endless belt-shaped type carrier, and a gear means at one end. , a rotating shaft that rotates by a driving force transmitted to a gear means, a paper feed roller rotatably supported on an axis parallel to the rotating shaft, and a paper feed roller that rotates only in a fixed direction. a driving means that selectively rotates, a locking tooth on a side facing the rotation shaft, and an engaging member that engages with the driving means on a side facing the driving means, a rack member rotatably supported parallel to the axis;
A printing hammer that selectively presses the type portion of the type carrier and the pressing member toward the paper, a projection that abuts the opposite side of the printing hammer and drives the printing hammer toward the paper, and a rack member. A threaded protrusion that engages with the latch teeth to perform carry-up,
Circumference around which the rack member is rotated when the engagement between the rack teeth and the ridges is released, and the engagement between the rack teeth and the ridges is restored, and the paper feed roller is rotated by the engagement means via the drive means during the recovery operation. a cam means having a pressing portion projecting in the direction, rotating integrally with the rotation shaft and pivotally supported so as to be slidable in the axial direction; and a printing hammer received via the pressing member. a lever member that rotates the rack member by a pressing force and releases the engagement between the rack tooth and the protrusion, and a lever member that supports the printing hammer, the cam means, and the lever member and is slidable along the rotation axis. A biasing means for constantly biasing the hammer holder toward the home position to return the hammer holder to the home position when the engagement between the hammer holder and the rack teeth and the protrusion is released, and a gear pivotally attached to the rotation shaft. The rotating shaft driving means includes a motor and rotates the rotating shaft via means.

[Effect]

The above means works as follows.

That is, when printing is completed, the position of the pressing member is selected so as to face the printing hammer, and then the rotating shaft rotates to perform the same printing operation as normal, and the printing hammer pushes the pressing member against the paper. Press in the direction. Then, the protrusion of the pressing member presses the lever member, causing the lever member to rotate. When the lever member rotates, the rack member is rotated and the meshing between the rack teeth and the protrusion of the cam means is released. When the engagement between the lock teeth and the protrusions is released, the hammer holder returns to the home position by the urging force of the urging means. During this time, the rotation shaft is rotated in the same direction by the motor, and after returning to the home position, the pressing part of the cam means comes into contact with the rack member, and rotates it in the opposite direction to the rotation direction by the lever member. rotate in the direction. Then, the locking member provided on the side opposite to the rack tooth forming side of the rack member rotates the drive means of the paper feed roller in the paper feed direction, and the paper feed roller receives a driving force from this drive means. Feeds paper by a specified amount.
At the same time, the printing hammer prepares for printing the next line.

Therefore, without using a motor or a complicated mechanism driven by a motor, it is possible to print paper using a simple structure by returning the printing hammer to its home position and preparing for the next printing operation. It is possible to send it.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

(Schematic Configuration) FIG. 1 is a schematic configuration diagram of a printer. A driving pulley 1 and a driven pulley 2 are arranged at a predetermined interval, and an endless type belt 3 is stretched 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 pulley 1 via a spring clutch (described later), and a print/carry gear 9 can mesh with the main gear 8. ing.

The printing/carrying gear 9 has printing/carrying as a rotating shaft.
One end of a carry shaft 10 is connected, and this print/carry shaft 10 is disposed between a driving pulley 1 and a driven pulley 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 freely slidable in the axial direction, and includes and supports a hammer, a carry/paper feed cam, a rack release lever, etc., as will be described later. One end of a holder return spring 12 is connected to the hammer holder 11, and the other end of the spring 12 is connected to a base (described later).
Therefore, the hammer holder 11 is always elastically biased toward the home position near the driven pulley 2 by the tensile force of the holder return spring 12.

A rack 13 is arranged near and parallel to the print/carry shaft 10, so that the carry/paper feed cam built in the hammer holder 11 can mesh with the rack teeth of the rack 13, as will be described later. There is. 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. A selection 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 19 denotes a position detection section provided near the driven pulley 2, which detects a reference position for selecting printed characters and a printed character position. 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 consists of type selection operation, printing/carrying operation, hammer holder return/paper feeding operation, and by sequentially repeating each of these operations, it is possible to print multiple lines. will be done. Each of the above-mentioned operations and related mechanisms will be explained in detail one by one, but first the configuration of the type belt 3 will be explained.

[Composition of type belt]

As shown in FIG. 3, the type belt 3 has an endless shape, and a large number of type parts 21 are individually provided along the circumferential direction at predetermined pitches on the outer circumferential side, and on the inner circumferential side, a large number of type parts 21 are individually provided along the circumferential direction. A large number of belt teeth 22 are provided at a predetermined pitch. Individual type section 2
1 and the belt tooth portion 22 are provided in pairs, that is, both are provided at the same pitch, and the type portion 21 (belt tooth portion 22) and the adjacent type portion 21
(belt tooth portion 22) are connected to each other by a thin connecting portion 23. These type portion 21, belt tooth portion 22, and connecting portion 23 are molded, for example, from 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. 3, the total length of the type belt 3 is, for example, the first type group G1 and the second type group G2.
It is divided into three areas: and the third type croup G3. For example, the first type group G1 is
"+", "-", "×", "÷", memory symbol "M",
It is a group of typefaces that are printed less frequently than numerical symbols, such as the total symbol "T", the subtotal symbol "◇", the count symbol "#", various alphanumeric symbols, or other special signals. . On the other hand, the second type group G2 and the third
The type group G3 is a group of frequently printed characters such as numerical signals, etc., and both groups each have the same type, and the characters are arranged in the same order.

Type part 2 is located at the boundary between type groups G1 and G3.
1 and the belt teeth 22 are not provided, but instead a push-down piece 24 is attached.
The push-down piece 24 is made of a relatively hard and slippery synthetic resin such as polyacetal resin, polyethylene resin, polyamide resin, etc., and has a side surface approximately C-shaped as shown in FIG. A notch 25 is formed in the middle for externally fitting onto the connecting portion 23 of the type belt 3. Note that the lower end of the push-down piece 24 protrudes slightly downward from the type section 21 and the belt tooth section 22 for a push-down function to be described later. On the other hand, push-down piece 2
As shown in FIG. 5, the front surface of the paper 4 is slightly recessed from the front surface of the printing section 21, that is, the printing surface, so that the push-down member 24 does not come into contact with the paper 16 during extrusion by a hammer 66, which will be described later. There is.

As explained in FIG. 1, the type belt 3 is stretched between the driving pulley 1 and the driven pulley 2,
Belt teeth 2 provided on the inner peripheral side of the type belt 3
2 mesh with the pulley teeth 26 (see second reference) of the driving pulley 1 and the driven pulley 2, respectively, so that the type belt 3 is rotated reliably without slipping. As shown in Figure 1, the drive pulley 1
is rotated counterclockwise in the figure, and the type belt 3 is rotated in the direction of arrow A, so that the tension side is formed between the driven pulley 2 and the driving pulley 1 on the side facing the paper 16. Furthermore, the pulley shaft 27 of the driven pulley 2 has a code plate 28 (see Fig. 2), which will be described later.
is attached to the code plate 28, and contact pieces 29 for detecting the position of characters are brought into elastic contact with the code plate 28, so that braking is always applied to the driven pulley 2. Because of this, there is no slack on the side of the type belt 3 facing the paper 16, and even if there is some vibration, the paper 16
There is no large swing along the feeding direction of 6.
Therefore, the accuracy of the printing position when printing is high,
Moreover, even if the distance between the type belt 3 and the paper 16 becomes narrower as printers become smaller, the type portion 21 will not come into contact with the paper 16 unexpectedly.

[Type selection mechanism]

Next, the type selection mechanism will be explained.

First, the drive mechanism for the type belt 3 will be explained mainly with reference to FIG. A base 30 made of hard synthetic resin has a substantially rectangular planar shape, and a motor mounting recess 31 is provided in the center of the front thereof, in which the DC motor 4 is installed. On the left side of the motor mounting recess 31, a pin-shaped gear support shaft 32 and a cylindrical gear support cylinder 33 are integrally protruded from the base 30 at a predetermined interval. A first idle gear 6 is rotatably fitted onto the gear support shaft 32, and a second idle gear 7 is rotatably fitted onto the gear support cylinder 33. The first idle gear 6 is provided with a helical portion 34 that meshes with the worm 5 attached to the DC motor 4, and a spur tooth portion 35 that meshes with the second idle gear 7. on the other hand,
The second idle gear 7 is formed with a spur tooth portion 36 that meshes with the spur tooth portion 35 of the first idle gear 6 . Therefore, the first idle gear 6 is connected to the gear support shaft 32.
By fitting the second idle gear 7 into the gear support cylinder 33, the worm 5, the first idle gear 6, and the second idle gear 7 are meshed with each other.

A pin-shaped main gear support shaft 38 and an ink roller support shaft 39 are respectively provided upright at the rear of the gear support cylinder 33 .
The spring clutch 40 and the driving pulley 1 are supported on the ink roller support shaft 39, and the ink roller 20 is supported on the ink roller support shaft 39, respectively.

Figures 6 to 8 regarding the shape of the main gear 8
This will be explained using figures. 6 is a plan view of the main gear 8, FIG. 7 is a sectional view taken along the line of FIG. 6, and FIG.
The figure is a view taken in the direction of the arrows in FIG. As shown in FIG. 7, the main gear 8 is arranged along its axial direction.
It has a spur tooth portion 41 that meshes with the spur tooth portion 36 of the second idle gear 7, a deformed bevel tooth portion 42 that meshes with the print/carry gear 9 at a predetermined timing, and a central cylindrical portion 43. There is. This deformed bevel tooth portion 4
2 is used to transmit power to the print/carry gear 9, so its shape etc. will be explained in the [Print/Carry Mechanism] section below. By fitting the main gear 8 onto the main gear support shaft 38, the main gear 8 meshes with the second idle gear 7, and the rotational driving force of the DC motor 4 is transmitted to the main gear via the worm 5, the first idle gear 6, and the second idle gear 7. The transmission is such that the gear 8 is rotationally driven in a constant direction, that is, counterclockwise in FIG. 1, at a constant speed.

A spring clutch 40 is interposed between the main gear 8 and the drive pulley 1 in order to transmit the rotational driving force of the main gear 8 to the drive pulley 1 or to interrupt the drive transmission.
As shown in FIG. 2, this spring clutch 40 is composed of a cylindrical drive arbor 44, a spring fixing tube 45, a type position selection ratchet 46, and a coil spring 47.

One lower end 47a of the coil spring 47 is inserted and locked into the inner circumference of the spring fixing tube 45,
On the other hand, the other end 47b on the upper side is inserted and locked into the inner circumference of the drive pulley 1. With the coil spring 47 tightly wound around the outer periphery of the drive arbor 44, the drive arbor 44 is passed through the center hole of the spring fixing ring 45 and the center hole of the ratchet 46 into the center recess of the drive pulley 1 (not shown). ), and the central cylindrical portion 43 of the main gear 8 is press-fitted into the inner peripheral portion of the drive arbor 44 so as to rotate integrally therewith.
In addition, a fan-shaped protrusion 48 formed on the inner circumference of the ratchet 46 engages with a fan-shaped recess (not shown) provided in the central recess of the drive pulley 1 (however,
A small gap corresponding to the so-called slack angle of the coil spring 47 is provided between the fan-shaped protrusion 48 and the fan-shaped recess in the rotation direction. The spring fixing tube 45, the ratchet 46, and the pulley 1 are tightly fitted so that they rotate together. Therefore, these three members and the main gear 8 are connected via the coil spring 47.

When the first pawl 50 of the selection lever 17 (described later) is not fitted into the teeth of the ratchet 46, the coil spring 47 is tightened and the main gear 8
The drive pulley 1 rotates integrally with the drive pulley 1. When the first pawl 50 of the selection lever 17 and the teeth of the ratchet 46 are fitted, rotation of the ratchet 46 is prevented.
Immediately, the coil spring 47 loosens, and the rotational driving force of the main gear 8 is no longer transmitted to the drive pulley 1.

In order to select type, it is first necessary to detect the reference position of the type belt 3. Next, a mechanism for detecting this reference position will be described. As explained in FIG. 1, the position detection section 19 is provided near the driven pulley 2. As shown in FIG. 2, this position detection section 19 includes a spherical button 51, an elastic metal piece 52,
It is mainly composed of a code plate 28 and a contact piece block 53. The button 51 is made of metal or hard synthetic resin, and is shown in FIGS. 2, 9, and 11.
As shown in the figure, the pulley shaft 27 of the driven pulley 2 is inserted into a buttonhole 55 provided on the movement trajectory of the type belt 3 near the shaft hole 54 into which it is inserted. Since the tip of the elastic metal piece 52 is disposed below the button hole 55, the button 51 is supported by the elastic metal piece 52, and as shown in FIG. It protrudes slightly from the top surface. The base end of the conductive metal piece 52 is bent vertically upward to form a metal piece terminal 56.
It penetrates from below to above the terminal array groove 57 formed in the base 30, as shown by the dotted line.

The pulley shaft 27 of the driven pulley 2 is tightly fitted into the center hole of the code plate 28, so that the code plate 28 rotates together with the driven pulley 2. Although not shown, a conductive pattern having a predetermined shape is formed on the lower surface of the code plate 28 to detect the rotation angle of the driven pulley 2, in other words, the amount of movement of the type belt 3. This conductive pattern is
For example, it may be formed by printing or by laminating thin metal plates. The contact piece block 53 is composed of a reset contact piece 58, a bifurcated common contact piece 59, a set contact piece 60, and a mounting plate 61 to which these are attached by insert molding or the like. The base end of each contact piece 58, 59, 60 is bent vertically upward and connected to a reset terminal 62, a common terminal 63, and a set terminal 64.
, which protrudes upward from the terminal arrangement groove 57 in line with the metal piece terminal 56 as shown by the dotted line. Although not shown, each terminal 56, 62, 63, 64 is connected to the control section by a lead wire.

The tips of the reset contact piece 58, the shorter common contact piece 59, and the set contact piece 60 are in elastic contact with the lower surface of the code plate 28, and the longer common contact piece 59
are opposed to each other at a predetermined distance below the elastic metal piece 52, as shown in FIG.

As the drive pulley 1 rotates, the type belt 3 rotates in the direction of arrow A (see Figures 1 and 3), and the push-down piece 24 attached to the type belt 3 rotates.
While the button 51 does not pass over the button 51, the button 51 is supported by the elastic metal piece 52 and slightly protrudes from the base 30, as shown in FIG.
2 and the common contact piece 59 are separated. Further, the type belt 3 rotates and the push-down piece 24 moves to the button 51.
When it reaches the top, the upper surface of the push-down piece 24 comes into contact with the outer flange 65 of the driven pulley 2, and as a result, the button 51 is pushed down against the elasticity of the elastic metal piece 52, as shown in FIG. , for which an elastic metal piece 5
2 contacts the common contact piece 59. This contact brings instantaneous electrical continuity between the metal piece terminal 56 and the common terminal 63, and from this signal it is possible to detect that the type belt 3 is currently at the reference position. Since the distance of each type part 21 from the type part 21 (or push-down piece 24) facing the hammer 66 when the type belt 3 is at the reference position is known in advance, the type belt 3 is moved after the reference position is detected.
By electrically counting the signal of the movement amount of the driven pulley 2, in other words, the rotation angle of the driven pulley 2, by the position detection unit 19, the type belt 3 is moved to the position where the type portion 21, which is commanded by the control unit, faces the hammer 66. can be rotated.

[Print/carry mechanism]

Next, we will discuss the printing/carrying mechanism.

As shown in FIG. 2, a solenoid mounting base 71 is located on the left side of the motor mounting recess 31 on the near side of the base 30.
is provided protrudingly, and the electromagnetic solenoid 18 is fixed to the mounting base 71 via a mounting piece 72. The actuator 73 of the electromagnetic solenoid 18 has an L-shaped planar shape, and a through hole 74 is formed in a horizontal portion provided between a base end 73a and a free end 73b. On the other hand, an actuator support shaft 75 is protruded from the side of the gear support cylinder 33 of the base 30, and the upper small diameter portion of the actuator support shaft 75 is inserted into the through hole 74, so that the actuator 73 is moved in a predetermined position around the support shaft 75. It is designed to rotate at an angle. An actuator biasing spring 76 is loosely fitted into the lower large diameter portion of the actuator support shaft 75, one end 76a of which is attached to the edge of the base 30 as shown by the dotted line, and the other end 76
b is the base end 7 of the actuator 73 as shown by the dotted line.
3a, respectively.

As shown in FIG. 2, a lever rotation shaft 77 extends below the selection lever 17.
is fitted into the central recess of the gear support cylinder 33. This selection lever 17 has a first pawl portion 50 that engages with the character position selection ratchet 46, as well as a
A second claw portion 78 that engages with the carry gear 9 and a vertical engagement groove 79 into which the free end 73b of the actuator 73 is inserted with some clearance are provided.

Next, regarding the shape of the printing/carry gear 9, the first
This will be explained using FIGS. 1 to 13. 11 is a front view of the printing/carry gear 9, FIG. 12 is a partially cut right side view thereof, and FIG. 13 is a rear view thereof. The printing/carrying gear 9 is provided with a front tooth section 80 and a rear tooth section 81 arranged one behind the other in the axial direction, and the front tooth section 80 has teeth partially (within a range of about 60 degrees from the center) in the circumferential direction. A toothless portion 82 in which no portion is formed is provided (see FIG. 11). On the other hand, the rear tooth section 81 is composed of one tooth section, and is provided behind the toothless section 82, as shown in FIG. Although no other tooth portion is provided in the circumferential direction of the rear tooth portion 81, the rear tooth portion 81
A notch 83 into which the second claw portion 78 of the selection lever 17 fits is formed near the. A shaft hole 84 with an oval-shaped front face is formed in the center along the axial direction, and one end of the printing/carrying shaft 10 having an oval-shaped cross section is tightly fitted into the shaft hole 84 . As shown in FIGS. 2 and 12, a circumferential groove 85 is formed on the rear outer periphery of the printing/carrying gear 9.
5 is fitted into a bearing 86 provided on the base 30, and the other end of the print/carry shaft 10 is inserted into the bearing 87, whereby the print/carry shaft 10 is rotatably supported on the base 30. .

As shown in FIG. 2, a spring support pin 88 is horizontally protruded diagonally below the bearing 86, and a gear biasing spring 89 is loosely fitted onto the spring support pin 88. That is, as shown in FIG. 14A, the gear biasing spring 89 is loosely fitted into the spring support pin 88, its base end 89a is in elastic contact with the end surface of the base 30, and its free end 89b is connected to the printing/carrying gear. It is in elastic contact with the cam portion 9a adjacent to the circumferential groove 85 of No.9.

This printing/carrying gear 9 is designed to mesh with a deformed bevel tooth portion 42 of the main gear 8 at a predetermined timing, and the deformed bevel tooth portion 42 has nine along the circumferential direction as shown in FIG. Radial grooves 90 are formed at equally divided positions, and teeth are provided on the inner peripheral side between the radial grooves 90.

Next, switching from drive transmission from main gear 8 to drive pulley 1 to drive transmission from main gear 8 to print/carry shaft 10 will be described. 14A and 14B and FIG. 15 show a state in which drive is transmitted from the main gear 8 to the drive pulley 1. That is, in this state, since the electromagnetic solenoid 18 is not energized, the base end 73a of the actuator 73 is pulled by the actuator biasing spring 76 as shown in FIG. As a result, the actuator 73 rotates clockwise around the actuator support shaft 75, and its free end 73b presses the engagement groove 79 of the selection lever 17 toward the front in the drawing. . Due to this pressing, the selection lever 17 is rotated counterclockwise about the lever rotation shaft 77, and as shown in FIG. 83, while the 15th
As shown in the figure, the first pawl 50 is spaced apart from the teeth of the character position selection ratchet 46.

14A and 14B show the printing/carry gear 9 in the same position. In FIG. 14B, the central cylindrical portion 43 of the main gear 8 is omitted in order to clearly show the state of the print/carry gear 9. That is, the second claw portion 7 of the selection lever 17
8 is fitted into the notch 83 of the print/carry gear 9, the missing tooth portion 82 of the print/carry gear 9
is opposed to the deformed bevel tooth portion 42, and the rear tooth portion 81
It does not fit into the radial groove 90 either. Therefore, the main gear 8 and the print/carry gear 9 have no engagement relationship, and as described above, the first claw portion 50 is separated from the character position selection ratchet 46, so the rotational driving force of the main gear 8 is spring clutch 40
The signal is transmitted to the drive pulley 1 via. In this way, the drive pulley 1 rotates in the direction of arrow B in the same manner as the main gear 8, thereby moving the type belt 3, and detecting the reference position and selecting type based on it as described above. .

A command is issued from the control unit to select a specified type portion 21, and based on the command, the electromagnetic solenoid 18 is activated.
is energized and excited. With this excitation, as shown in FIG. 16, the base end 73a side of the actuator 73 is attracted to the electromagnetic solenoid 18 against the elasticity of the actuator biasing spring 76, thereby causing the actuator 73 to move counterclockwise to the selected position. The levers 17 each rotate clockwise. This rotational movement causes the second pawl portion 78 of the selection lever 17 to separate from the notch portion 83 of the print/carry gear 9, and the first pawl portion 50 engages with the tooth portion of the character position selection ratchet 46 instead. This prevents the rotation of the ratchet 46, and the action of the spring clutch 40 cuts off the drive transmission to the drive pulley 1, so that the selected type portion 21 is held at a position facing the hammer 66.

The second claw part 78 is the notch part 8 of the printing/carry gear 9
3, the printing/carrying gear 9 is slightly rotated by the elasticity of the gear biasing spring 89 as shown by arrow C in FIG. 14A. Then, the rear toothed portion 81 fits into the radial groove 90 of the main gear 8, and the rotation of the main gear 8 pushes the rear toothed portion 81 and continues to rotate, and this time the front toothed portion 80 meshes with the deformed bevel toothed portion 42. At the same time, the rotational driving force of the main gear 8 is transmitted to the print/carry shaft 10 via the print/carry gear 9 and rotates in the direction of arrow C.

As shown in FIGS. 2 and 17, the hammer holder 11, which is slidably attached to the print/carry shaft 10, has insertion holes 91, 91 on both rear side plates through which the print/carry shaft 10 can freely rotate. formed,
A hammer rest 92 extends horizontally from the rear to the front inside the upper part. A spring hanging pin 93 is protruded from the rear of one of the side plates, and a long groove 94 is cut horizontally in front of the spring hanging pin 93 facing toward the spring hanging pin 93. Lever support portions 95 cut into shapes are formed diagonally below and in front of the long groove 94 on both side plates, and the hammer holder 1
A partition wall portion 96 is suspended in front of the main body 1 . As shown in FIG. 18, this partition wall portion 96 has a projection opening 97 in the middle thereof large enough to allow one of the selected character portions 21 to project out, and the partition wall portion 96 is provided on both sides of the projection opening 97. Note that, as shown in FIG.
If this is done, the type portion 21 can be smoothly projected from the projection opening 97.

A carry/paper feed cam 99 connected to the print/carry shaft 10 by a spline is built in below the hammer placement portion 92 of the hammer holder 11 . The cam 99 includes a hammer drive section 100 extending in one direction from the center toward the outer periphery, a carry cam section 102 having a single protrusion 101 on the outer periphery, and a return rack 13 for paper feeding. It consists of an elliptical rack rotation part 103 which is integrally formed by molding synthetic resin. FIG. 23 is a developed view of the cam surface of the carry cam portion 102, and shows the protrusion 1
01 is a circumferentially extending circumferential protrusion 101a that is provided over about half of the circumferential direction, and a spiral protrusion 101b that is provided over the remaining half of the circumferential direction. These protrusions 101a and 101b are continuous. The protrusions 101 are adapted to mesh with rack teeth 104 provided at equal intervals on one side of the rack 13.

The hammer 66 is placed on the hammer placement part 92 with the extrusion part 105 facing the partition wall part 96, and the convex part 106 projecting upward is slidably fitted into the guide groove 107 formed on the upper surface of the hammer holder 11. There is. A spring hook pin 108 is protruded from one side of the hammer 66, and as shown in FIG.
protrudes outward from the and hammer holder 1
A tension spring 109 is stretched between the spring hook pin 93 of No. 1 and the spring hook pin 108 of the hammer 66, and the hammer 66 is elastically biased in a direction away from the type belt 3 (backwards) by the tension spring 109. . A receiving portion 110 is provided below the spring hook pin 108, with which a hammer drive portion 100 of the carry/paper feed cam 99 comes into contact with rotation.

24 and 25 are diagrams for explaining the printing operation, and FIG. 24 shows the state before printing, and FIG.
The figures are diagrams each showing a printed state. In the state before printing, as shown in FIG. 24, the hammer 66 is pulled rearward by the tension spring 109, and is positioned by a stopper (not shown). Therefore, the type belt 3 (type part 21)
is located between the partition wall portion 96 of the hammer holder 11 and the extrusion portion 105 of the hammer 66, and is slightly separated from the extraction portion 105. Further, the hammer driving section 100 faces downward and does not come into contact with the receiving section 110 of the hammer 66.

The printing/carrying shaft 10 rotates once in the direction of arrow C by the drive transmitted from the main gear 8, but the printing operation is performed continuously in the first half of the revolution, and the carry operation is performed continuously in the second half of the revolution. ing. In other words, printing/
When the carry shaft 10 rotates in the direction of arrow C, the carry/paper feed cam 9 spline-coupled thereto
9 also rotates together, but on the front half circumference, the circumferential protrusion 1
Since 01a is meshing with the easy tooth 104,
The carry/paper feed cam 99 (along with the hammer holder 11, hammer 66, etc.) is not moved and only makes half a turn on the spot. Halfway around the carry/paper feed cam 99, the hammer drive section 100 comes into contact with the receiving section 110 of the hammer 66 as shown in FIG. is pushed forward against the Selected type part 2 facing paper 16
1 is projected forward from its ejection opening 97 by the push-out of the hammer 66 and is pressed against the paper 16 to perform desired printing. Note that, as shown in FIG. 18, since the partition wall portions 96 are provided on both sides of the ejection opening 97, unnecessary printing such as side printing is not performed. Print/carry cam 99
As the hammer drive unit 100 moves upward from the lateral position as shown in FIG. During this reciprocating movement of the hammer 66, the hammer 66 is properly guided by the engagement between the hammer mounting portion 92, the convex portion 106, and the guide groove 107, and the engagement between the spring hook pin 108 and the long groove 94.

When the printing/carrying cam 99 subsequently rotates, the spiral protrusion 101b from earlier engages with the lock tooth 104, and as it rotates, it resists the elasticity of the hammer return spring 12 and moves the hammer holder 11, hammer 66, printing/digit The raising cam 99 and the like move toward the upper digit (to the left in FIG. 1) by an amount corresponding to one digit, thereby performing a carry.

In this way, by repeating the character selection, printing operation, and carry operation, one line is printed.

In FIG. 2, a rack receiving through hole 111 is bored diagonally below the bearing 86, into which a cylindrical portion 112 at one end of the rack 13 is rotatably inserted.
An arcuate rack receiving recess 114 provided diagonally below the bearing 87 has a cylindrical portion 11 at the other end of the rack 13.
3 is rotatably fitted, and the rack 13 is positioned. A paper guide wall 117 is provided at the back of the rack receiving through hole 111 and the rack receiving recess 114, and has two arms 116 provided at a predetermined interval at the bottom thereof, each rotatably supporting both ends of the paper feed shaft 115. It is set up.

[Hammer holder return/paper feed mechanism]

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

As mentioned above, once one line has been printed,
It is necessary to return the hammer holder 11 to its home position again to prepare for printing the next line. Although the explanation was omitted in the above [Printing/Carry Mechanism] section, the lever support portion 95 of the hammer holder 11,
Both ends of the lock release lever 121 are rotatably supported by the lever 95. This release lever 12
1 is provided with a receiving claw 122 that projects upward and a slide protrusion 123 that projects downward. As shown in FIGS. 26 and 27, the rack release lever 121 is disposed between the hammer 66 and the rack 13, and before the rack 13 is rotated, the receiving pawl 122 is disposed as shown in FIG. It is located diagonally in front of the type belt 3 below.
On the other hand, the slide protrusion 123 is inserted into a hook groove 124 formed on the upper surface of the rack 13 along its longitudinal direction, and as the hammer holder 11 is transferred, the slide protrusion 123 is inserted into the hook groove 124. It will slide.

FIG. 26 shows the state before starting the hammer holder return. In this state, the position of the push-down piece 24 is selected so as to face the hammer 66, and since the push-down piece 24 protrudes below the type belt 3, the upper end of the receiving claw 122 It is located slightly above the bottom edge of.
As in a normal printing operation, the hammer driving section 100 rotates in the direction of arrow C, thereby pushing the push-down piece 24 toward the paper 16 via the hammer 66. As the push-down piece 24 moves horizontally, the rack release lever 121 rotates in the direction of arrow D as shown in FIG. Since they are engaged, the rack 13 is rotated in the direction of arrow E as the rack release lever 121 is rotated. The rack 13 thus tilted in the direction of arrow E remains in the tilted state until it is rotated back to its original position by a rack rotating section 103, which will be described later. Then, the rack tooth 104 separates from the protrusion 101 of the print/carry cam 99, and the engagement between the rack 13 and the print/carry cam 99 is released. Then, the hammer holder 11 containing the hammer 66, print/carry cam 99, and rack release lever 121 starts to return to the home position side along the print/carry shaft 10 by the tensile force of the holder return spring 12. .

As shown in FIG. 2, on the right end of the rack 13, there is a two
Two chevron-shaped paper feed intermediate lever portions 125 are provided in a protruding manner. On the other hand, Figures 2, 21 and 2
As shown in FIG. 2, a substantially disk-shaped intermediate stopper portion 126 is integrally provided on the end face of the rack rotating portion 103 of the carry/paper feed cam 99, and a stopper portion 126 in the form of a disk is provided at a predetermined position of the stopper portion 126 as shown in FIG. Rack 1
A fan-shaped cut-out portion 127 is formed to have a size through which the paper feed intermediate lever portion 125 of No. 3 is inserted. Therefore, when the hammer holder 11 returns to the home position side, the end surface of the paper feeding intermediate lever section 125 on the rack tooth 104 side comes into contact with the outer surface of the intermediate stopper section 126, and the movement of the hammer holder 11 is stopped. Since the hammer holder 11 is thus stopped at an intermediate position close to the home position, the easy rotation part 10 of the carry/paper feed cam 99
3 and the paper feed intermediate lever portion 125 of the rack 13 are at mutually shifted positions and do not face each other.

A paper feeding operation is performed in parallel with this hammer holder return operation, and this operation will be explained next. As shown in FIG. 2, an engagement pin 128 is provided on the opposite side of the rack 13 from the rack teeth 104, projecting parallel to the axial direction of the rack 13. A paper feed shaft 115 is arranged behind this rack 13 and parallel to it, and two rubber rings 12 are placed approximately on the left half of it at a predetermined interval.
A paper feed roller 14 having a roller 9 elastically fitted thereon is fixedly attached thereto. As shown in FIGS. 2 and 28, a driven side paper feed ratchet 130 is attached to the right end surface of the paper feed roller 14, and the paper feed shaft 11
The drive side paper feed ratchet 131 is rotatably supported on the drive side paper feed ratchet 131. As shown in FIG. 28, the drive side paper feed latch 131 is always biased in the direction of engagement with the driven side paper feed latch 130 by the elasticity of a ratchet biasing spring 132 inserted between it and one arm 116. ing. As shown in FIGS. 2, 29, and 30, a side surface of the drive-side paper feed latch 131 partially protrudes, into which the engaging pin 128 of the rack 13 is fitted horizontally and rotatably. A pin groove 133 is provided. Further, as shown in FIG. 30, a driven roller 134 that rotates with the paper feed roller 14 is arranged diagonally above the paper feed roller 14, and the paper 16 is held between the paper feed roller 14 and the driven roller 134. .

FIG. 29 shows the state before paper feeding is started. In this state, type selection or printing/
This means that a carry operation is being performed, and the rack 13 and the carry/paper feed cam 99 are engaged.

As mentioned above, the third
When the rack 13 rotates in the direction of the arrow E as shown by the solid line in Fig. 0, the drive side paper feed latch 131 is moved around the paper feed shaft 115 by the engagement between the engagement pin 128 and the pin groove 133 as shown by the solid line. It rotates by a predetermined angle in the direction of arrow F. During this rotation in the direction of arrow F, the drive side paper feed latch 131 and the driven side paper feed latch 130 have tooth shapes that do not mesh with each other, so that when the rack 13 is completely collapsed, the drive side paper feed latch 131 and the driven side paper feed latch 130 are rotated as shown in FIG. The pin groove 133 of the side paper feed ratchet 131 is stopped with the pin groove 133 facing slightly diagonally upward, and is in a standby state for paper feeding.

On the other hand, when the rack 13 rotates, the rack teeth 104 of the rack 13 disengage from the carry/paper feed cam 99, so the hammer holder 11 quickly returns to the home position due to the tensile force of the holder return spring 12 described above. Return. Note that when the hammer holder 11 returns to the home position from the lower digit, the hammer holder 11 reaches near the home position during the remaining 3/4 rotation of the carry/paper feed cam 99; - During the rotation of the paper feed cam 99, the intermediate stopper portion 126 of the carry/paper feed cam 99 comes into contact with the side surface of the paper feed intermediate lever portion 125 of the rack 13, and the rack rotating portion 10
3 and the paper feed intermediate lever part 125, the rack 13 is not scraped up by the rack rotating part 103, and therefore the rack 13 is not in the fallen state and driven as shown in FIG. The standby state of the side paper feed ratchet 131 is maintained as it is. Then, when the carry/paper feed cam 99 completes one rotation, the fan-shaped cutout portion 127 of the intermediate stopper portion 126 is removed from the paper feed intermediate lever portion 12 of the rack 13.
5, and only then can the hammer holder 11 completely return to its home position.

As mentioned above, when the print/carry shaft 10 completes one rotation for the hammer holder return (at this time, the electromagnetic solenoid 18 is already in the de-energized state), the tensile force of the actuator biasing spring 76 causes As shown in Fig. 14A, the selection lever 17
The second claw part 78 is the notch part 8 of the printing/carry gear 9.
3, thereby causing the print/carry gear 9
(Print/carry shaft 10) is prevented from rotating and becomes stationary.

At the same time, the first pawl 50 of the selection lever 17 is disengaged from the teeth of the type position selection ratchet 46, and the rotational driving force of the main gear 8 is transmitted to the drive pulley 1, and the type belt 3 is rotated. Rotate. Note that during this rotation of the type belt 3, the rack teeth 104 of the rack 13 are disengaged from the carry/paper feed cam 99, so there is sufficient time for the hammer holder return as described above. become. Next, the position of the type belt 3 is selected so that the push-down piece 24 faces the hammer 66, and the electromagnetic solenoid 18 is energized at the position where the push-down piece 24 faces the hammer 66, and the same process as described above is carried out. When the print/carry shaft 10 rotates approximately 1/4 of a turn, the push-down piece 24 is pushed out by the hammer 66 as shown in FIG. The difference from the hammer holder return operation is that the rack 13 has fallen down and the drive-side paper feed ratchet 131 is in a paper feed standby state, so the push-down piece 24 simply moves back and forth. On the other hand, in this case, the holder return spring 12
Since the hammer holder 11 is moved by the tensile force of ) is possible, and then the carry/paper feed cam 9
9 rotates, the rack rotating part 103 hits the paper feed intermediate lever part 125, and the fallen rack 13 is moved in the direction of arrow G as shown by the dotted line in FIG. 30 via the paper feed intermediate lever part 125. Rotate to. With this rotation, the rack 13 returns to its original position, and the rack teeth 104 engage with the protrusions 101 of the carry/paper feed cam 99, and as the rack 13 rotates, the drive side paper feed latch 131 moves in the direction of arrow H. Rotate to. Since the driving side paper feed latch 131 and the driven side paper feed latch 130 have tooth shapes that mesh with each other when rotating in the direction of arrow H, the paper feed roller 14 also rotates in the direction of arrow H. and thereby form 16
is pushed out in the direction of arrow I, and the paper is fed by an amount equivalent to half a line.

When the carry/paper feed cam 99 rotates once, the transmission of the driving force is switched by the selection lever 17.
The type belt 3 is rotated and the position is selected so that the push-down piece 24 faces the hammer 66 again.
While the carry/paper feed cam 99 rotates once, the rack 13 reciprocates in the direction of arrow E and the direction of arrow G as shown in FIG. 1
4) is rotated in the direction of arrow F to enter the paper feeding standby state, and as it continues to be rotated in the direction of arrow H, the paper 16 is pushed out in the direction of arrow I, and an amount equivalent to the remaining half line is pushed out. Paper is fed.

In this embodiment, the paper feed roller 14 is rotated twice to feed the paper by an amount equivalent to one line, but for example, by increasing the diameter of the paper feed roller 14, one rotation is equivalent to one line. It is also possible to feed paper by the same amount.

As shown in FIG. 30, the paper 16 is sent out by the cooperation of the paper feed roller 14 and the driven roller 134.
is pushed up through the gap between the guide plate 15 and the paper guide wall 117 so that the area to be printed next faces the hammer 66, as shown in FIG. 24, for example. As mentioned above, the paper guide wall 117 is attached to the base 3.
Although the guide plate 15 is formed integrally with the paper guide wall 117, as shown in FIG.
5, both ends of which are tightly fitted to each other, so that it is fixed so that it does not wobble. This guide plate 1
5 is made of a thick metal plate and also serves as a platen.

This printer is designed to minimize play in the carry/paper feed cam 99 relative to the print/carry shaft 10. Therefore, for example, when the printer is used at low temperatures, the hammer holder 11 does not return easily and takes time to return. In this printer, since the character selection operation is performed after the return of the hammer holder 1 is started until the fallen rack 13 is lifted up, the hammer holder 1
There is plenty of time before the operator returns to his home position. Moreover, unless the hammer holder 11 (carry/paper feed cam 99) completely returns to the home position, the rack 13 cannot be rotated to the position where it can be carried.
There is no possibility that the rack 13 rotates during the return of the hammer holder 11 and the carry/paper feed cam 99 engages with the rack 13 at an intermediate position to prevent the return operation of the hammer holder 11.

〔Effect of the invention〕

As is clear from the above explanation, in a serial printer using a type belt, the paper feed roller is driven in conjunction with the return operation of the print hammer to the home position, and the paper is fed in a predetermined manner. According to the invention, since there is no need for a paper feeding motor or a paper feeding mechanism directly driven by a printing motor, costs can be reduced, and the apparatus can be made smaller and lighter. Furthermore, since it is linked with the return operation of the home position, there is no risk that only the paper feeding mechanism will malfunction, and an improvement in reliability can be expected.

[Brief explanation of the drawing]

The figures are all for explaining the printer according to the embodiment of the present invention, and FIG. 1 is a schematic configuration diagram seen from a plane of the printer, FIG. 2 is an exploded perspective view of the printer, and FIG. 3 is a plane view of a type belt. Explanatory drawings, Fig. 4 is a partially enlarged perspective view of the type belt, Fig. 5 is a partially enlarged plan view of the type belt, Fig. 6 is a plan view of the main gear, and Fig. 7 is on the line of Fig. 6. , FIG. 8 is a view taken in the direction of the arrow in FIG. 6, FIGS. 9 and 10 are enlarged sectional views of the reference position detection section, FIG. 11 is a front view of the printing/carry gear, and FIG. A right side view with a part cut away, Fig. 13 is a rear view of it, Fig. 14 A and B are explanatory diagrams showing the layout of the printing/carry gear, and Figs. 15 and 16 are selection levers. Fig. 17 is a perspective view of the hammer holder, Fig. 18 is a partial front view of the hammer holder, Fig. 19 is an enlarged cutaway plan view of the partition in the hammer holder, and Fig. 20 is a diagram of the carry-up cam part. A front view, FIG. 21 is a side view, FIG. 22 is a rear view, and FIG. 23 is a developed view of the cam surface.
24 and 25 are side views of the printing section for explaining the printing operation, and FIGS. 26 and 27 are side views of the main parts for explaining the rotating operation of the rack.
FIG. 28 is a plan view of the main part of the paper feeding section, and FIGS. 29 and 30 are explanatory diagrams showing the paper feeding operation. 3... Type belt, 4... DC motor, 8...
Main gear, 9...Print/carry gear, 10...
Print/carry shaft, 11...Hammer holder, 12...
...Holder return spring, 13...Rack, 14...
... Paper feed roller, 16 ... Paper, 24 ... Push-down piece, 66 ... Hammer, 99 ... Carry/paper feed cam, 100 ... Hammer drive section, 101 ... Projection, 102 ... Girder Raising cam, 103... Rack rotation part, 104... Rack tooth, 115... Paper feed shaft, 121... Rack release lever, 128... Engagement pin, 130... Driven side paper feed ratchet, 1
31...Drive side paper feed ratchet.

Claims (1)

[Scope of Claims] 1. An endless belt-shaped type carrier that rotates in a predetermined direction; a protruding pressing member provided at a predetermined position on the endless belt-shaped type carrier; and a gear means at one end; A rotating shaft that rotates by a driving force transmitted to the means, a paper feed roller that is rotatably supported on an axis parallel to the rotating shaft, and a paper feed roller that is selectively moved only in a certain direction. a driving means that rotates to the rotational axis; and an engaging member that has lock teeth on the side facing the rotational shaft and engages with the driving means on the side opposite the driving means, A rack member rotatably supported in parallel; a printing hammer that selectively presses the type portion and pressing member of the type carrier toward the paper side; A drive protrusion that presses and drives the printing hammer in the direction of the paper, a spiral protrusion that engages with the rack teeth of the rack member to perform carry, and a slider that rotates the rack member when the engagement between the rack teeth and the protrusion is released. It has a pressing part protruding in the circumferential direction that restores the engagement between the teeth and the protrusion and rotates the paper feed roller by the engaging means via the driving means during the recovery operation, and is integrated with the rotating shaft. The rack member is rotated by the pressing force from the printing hammer received via the cam means which is rotatably rotated and is slidably supported in the axial direction of the cam means, and the pressing member, and the rack tooth and the projection are rotated. a lever member that disengages the engagement with the strip; a hammer holder that supports the printing hammer, the cam means, and the lever member and is slidable along the rotation axis; a biasing means that always urges the hammer holder toward the home position to return the hammer holder to the home position, and a rotation including a motor that rotates the rotation shaft via a gear means attached to the rotation shaft. A printer characterized in that it is equipped with a dynamic shaft drive means.