JPS5910917B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing mechanism of a serial printer suitable for being attached to a display section of a small desktop calculator or a measuring machine.

Desktop calculators and measuring machines often display calculation results and measured values digitally on a liquid crystal display.

Moreover, recently it has become possible to record these calculation results and measured values on recording paper using many small serial printers. This type of serial printer used in these devices is subject to considerable restrictions on the parts it can be mounted on, so it is desirable to make it as compact as possible. The actual situation is that it is difficult to miniaturize because it includes many complicated mechanisms such as the printer drive mechanism and paper feed mechanism. In addition, recent desktop electronic calculators have various calculation functions, and for this purpose, in addition to the numbers 0 to 9, it is required to print about the same number of function symbols as these 10 numbers. be done.

However, if numbers and function symbols are housed in the same type wheel, the diameter of the type wheel increases, which increases the size of the printer as a whole, making it unsuitable for use as a printer, especially for use in portable desktop electronic computers.
In order to solve this problem, the applicant previously proposed a serial printer in which the type wheel for function symbols and the type wheel for numbers are separated, and only the type ring for numbers is moved in the direction of the digits. did.

This application, as shown in Japanese Patent Application Laid-Open No. 52-46930, associates two type wheels with hammer bodies that each operate independently. For this reason, the mechanism becomes complicated because two hammer bodies are selectively operated by the same driving source. The applicant of this application has also previously proposed a serial printer that selectively illuminates two type wheels using a single hammer body, eliminating the selection mechanism for the two hammer bodies described above. The serial printers shown in the above-mentioned Japanese Patent Laid-Open Nos. 52-46930 and 53-56514 have a simple mechanism, small size, and light weight, so they are difficult to install in desktop electronic computers, etc. Optimal.

However, the pulse motor for rotating the type wheel,
Since a relatively large electromagnetic plunger is used to drive the type wheel and press body, and a relatively large electromagnetic plunger is used to feed the paper and release the carriage, the parts cost of the drive source and the space occupied by it are reduced. was relatively large and was a victory. On the other hand, in a serial printer using two type wheels, a serial printer that performs type selection, printing, digit feeding, paper feeding, etc. with a single motor was published in Japanese Patent Application Laid-Open No. 54-6832.
It is proposed as No. 5.

However, since the above-mentioned motor is configured to rotate in forward and reverse directions, there is a certain limit to improving the printing speed, and in addition, the motor is relatively expensive and its control is complicated. In addition, the mechanism is complicated because it is necessary to select and lock each of the two type wheels separately. The present invention is a novel invention that improves the conventional drawbacks as described above, and its purpose is to provide a small and lightweight serial printer.

The next objective is to create a printing device in which one motor, which is one drive source, is always rotated in a fixed direction, and the rotational force of the motor can be appropriately switched by a clutch mechanism to select characters and perform printing operations. Our goal is to provide the following. Next, one embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view of a printing device according to the present invention.
is an iron frame plate.

Side plates 1a and 1b are attached to the frame plate 1 so as to face each other. Note that 1c is a support plate that supports the upper ends of the side plates 1a and 1b. A rail 2 is spanned between the side plates 1a and 1b. Reference numeral 3 denotes a carriage, which can be moved left and right along the rail 2, that is, in any direction.

4 is a type wheel for printing function symbols, and 5 is a type wheel for printing numbers, which are held in the carriage 3.

A rotating shaft 6 passes through each type ring. Each type wheel is rotated by the rotary shaft 6, but the rotary shaft 6 can be freely moved in the axial direction within a predetermined range independently of each other.
Reference numeral 7 designates a tension spring, one end of which is fixed to the side plate 1a and the other end of which is fixed to the carriage 3, pulling the carriage 3 to the initial position, that is, the position shown in FIG.

Reference numeral 8 denotes a moving wire or thread that moves the carriage 3 (pulls it in the direction of the arrow).

Note that 9 is a guide member that guides the tension spring 7, and 10 is a guide member that guides the tension spring 7.
are guide members for the shift wire 8, and the side plates 1a,
1b. Reference numeral 11 denotes a printing hammer, which has a notch 11a at its right end for preventing printing.

A non-circular hammer cam 12 drives the printing hammer 11, and is attached to a drive shaft 13.

14 is a recording sheet inserted between the printing hammer 11 and the type wheels 4 and 5, 3b is an ink roller, and 15 is a stopper disc.

First, before giving a detailed explanation of the first drive mechanism, the printing operation will be explained.

When the rotary shaft 6 rotates and the desired function symbol comes to the printing position, the drive shaft 13 rotates...marker cam 12
presses the printing hammer 11.

For this purpose, the printing hammer 11 presses the recording paper 14 against the type ring 4, and the function symbol is printed. Note that at this time, since the type ring 5 is located in the notch 11a, no numbers are printed. When printing of the first digit is completed, the shift wire 8 is pulled in the direction of the arrow to shift the carriage 3 to the left by one digit.

At this time, the type wheel 5 held by the carriage arm 3a shifts to the second digit, but although the type wheel 4 is pushed by the spring 14'' and shifts to the left, it does not follow the movement of the carriage 3 and prints. It stops at a position facing the notch 11a of the hammer 11, and remains in this position until one line of printing is completed and the carriage returns. (Although not shown, the type wheel 4 is provided on the shaft 6. (It comes into contact with the stepped part.)
On the other hand, when the carriage 3 shifts to the second digit and the desired number comes to the printing position, the printing operation as described above is performed and the second digit is printed.

After such a printing operation continues, when one line of printing is completed, the winding member of the shift wire 8 becomes free. Therefore, the carriage 3 returns to the initial position shown in the first figure by the tensile force of the tension spring 7, and the printing operation for one line is completed. (If necessary, please refer to the above-mentioned Japanese Patent Application Laid-Open No. 5
See No. 3-56514. ) Next, details of the printing mechanism will be explained.

The printing mechanism according to the present invention includes (1) a rotating shaft mechanism that rotationally drives the type wheels 4 and 5, (2) a shaft mechanism that rotates the hammer cam 12 for driving the printing hammer, and (3) feeding the recording paper. It has three paper feed shaft mechanisms, which are organically connected using a gear mechanism and a clutch mechanism to perform various sequence operations.

(1) Rotating shaft mechanism for rotationally driving the type wheels 4 and 5 In FIG. 2, 16 is a fixed bearing, which is fitted into a half-moon-shaped hole 1b-1 drilled in the side plate 1b so as not to rotate. The rotating shaft 6 is inserted through the center hole 16a1f.

Reference numeral 17 denotes a reverse rotation prevention ring, which is tightly fitted to the rotating shaft 6 and rotates integrally therewith.

Reference numeral 18 denotes a coil spring for preventing reverse rotation, which is wound in a direction that unwinds when the rotating shaft 6 is twisted in a predetermined rotational direction.

The fixed 1 bearing 16 and the anti-reverse wheel 17 are provided with drum parts 16b and 17a having the same diameter.
The sides of 6b and 17a are closely spaced. A coil spring 18 is wound around these drum parts. Note that the inner diameter of the coil spring 218 is slightly smaller than the outer diameter of each drum portion. When the rotating shaft 6 is rotating in a predetermined direction, the coil spring 18 is driven in the direction in which it is unwound, so the drum parts 16b and 17a are separated, but the rotating shaft 6 If the coil spring 18 tries to rotate in the increasing direction even if the rotation is slightly insufficient, the coil spring 18 tightens the drum portions 16b and 17a, so that they are connected and the rotating shaft 6 cannot rotate in the opposite direction. 19 is a gear loosely fitted to the rotating shaft 6;
It has a drum part 19a.

20 is a holding cylinder, → 11J has a hole 20a through which the drum part 19a of the gear 19 passes, and a groove 20b on the outer periphery.
is formed.

21 is a cylindrical body with a drum part on one side. 21a, and a groove 21b is formed on the circumferential surface.

22 is a coil spring, and bent end portions 22a and 22b are formed at both ends.

Reference numeral 23 denotes a ratchet gear, which has a boss portion 23a on one side, and is hollow inside so as to accommodate a clutch to be described later.

When assembling the clutch portion 21A, first, one end 22b of the coil spring 22 is inserted into the groove 21b of the cylindrical body 21, and approximately half of the coil spring 22 is fitted into the drum portion 21a of the cylindrical body 21 ( The inner diameter of the coil spring 22 is slightly smaller than the outer diameter of the drum parts 19a and 21a, which have the same diameter.)

Next, the drum part 19a of the gear 19 is inserted into the hole 2 of the holding cylinder 20.
The remaining coil spring 22 is press-fitted into the drum part 19a, and the other end 22a of the coil spring is inserted into the groove 20b of the holding cylinder 20. That is,
Each member 19, 20, 21 is connected via a coil spring, and is coupled so as to rotate together in a predetermined direction (the tension direction of the coil spring). Further, when assembling the holding cylinder 20, it is rotated by a minute amount with respect to a ratchet gear 23, which will be described later.
It is possible to absorb variations in relative angles between both ends 22a and 22b of the coil spring 22 (which causes errors that are difficult to avoid in manufacturing). Then, the members assembled as described above are press-fitted into the cylindrical body 21 onto the rotating shaft 6, and then the ratchet gear 23 is placed over the cylindrical body 21.

At this time, each member is attached to the rotating shaft 6 by aligning the fan-shaped protrusion 21d provided on the other drum part 21c of the cylindrical body 21 with the fan-shaped hole 23c communicating with the center hole 23b at the end of the ratchet gear 23. It's becoming like that. In addition, when the fan-shaped protrusion 21d and the fan-shaped hole 23c are engaged with each other, the holding tube 20 is adjusted and rotated to achieve a predetermined mounting position as described above.

Further, the engagement relationship between the fan-shaped protrusion 21d and the fan-shaped hole 23c is designed to allow a slight margin, and is set to smooth the tensioning and loosening of the coil spring 22 when the clutch is operated, which will be described later. . The coil spring 18 and the coil spring 22 are set to wind in directions opposite to each other with respect to the rotation direction of the rotary shaft 6, and when the gear 19 rotates in response to the rotation of a motor, which will be described later, the rotation is caused by the coil The connection of the spring 22 allows the transmission to be transmitted to the rotating shaft 6 via the cylindrical body 21, and when the ratchet gear 23 is prevented from rotating by a locking member to be described later, the cylindrical body 21 rotates together with the ratchet gear 23. When the rotation of the gear 19 is stopped, the coil spring 22 immediately loosens, thereby cutting off rotational transmission between the gear 19 and the cylindrical body 21 (ie, the rotating shaft 6).

When the rotating shaft 6 attempts to rotate in the opposite direction (the opposite direction to the rotation caused by the motor drive) when the rotating shaft 6 stops rotating, the aforementioned coil spring 18 immediately moves between the fixed bearing 16 and the anti-reverse ring 1.
7 to prevent reverse rotation of the rotating shaft 6. (2) Shaft mechanism for rotating the hammer cam 12 for driving the printing hammer In FIG. 3, 24 is a fixed bearing, which has a semicircular hole 1b-2 drilled in the side plate 1b.
It is fitted into the center hole 24a so that it cannot rotate.
A drive shaft 13 is inserted into.

Reference numeral 25 denotes a reverse rotation prevention wheel, which is tightly fitted to the drive shaft 13 and rotates integrally therewith.

Reference numeral 26 denotes a coil spring for preventing reverse rotation, which is wound in a direction that unwinds when twisted in the rotational direction of the drive shaft 13.

The fixed bearing 24 and the anti-reverse wheel 25 are provided with drum parts 24b and 25a having the same diameter.
The sides of 5a are closely spaced. A coil spring 26 is wound around these drum parts. Note that the inner diameter of the coil spring 26 is slightly smaller than the outer diameter of each drum portion. When the drive shaft 13 is rotating in a predetermined direction, the coil spring 26 is driven in the direction in which it is unwound, so the drum parts 24b and 35a are separated, but the drive shaft 13 is rotated even slightly. If you try to rotate in the opposite direction,
The coil spring 26 tightens the drum parts 24b and 25a, so that they are connected, and the drive shaft 13 cannot rotate in reverse. 27 is a gear into which the drive shaft 13 is loosely fitted, and a ratchet gear 27a is fixed or integrally formed on the side surface.

A clutch plate 28 rotates together with the drive shaft 13.

The clutch plate 28 has two notches 28a and 28d in the diametrical direction on its outer periphery, and a tip 29a of the pin 29 on the side.
It has a hole 28b into which the pin is fitted and a pin is fixed, and further has a body part 28c on the side surface around which a helical spring 30 is wound.

Both ends of the helical spring 30 are bent outward to form tip portions 30a,
30b. 31 is a locking plate.

On the outer periphery of the locking plate 31, there are two notches 31a in the diametrical direction.
31b is formed, and has a circular hole 31c in the center through which the drive shaft 13 passes, and a long hole 31 drilled along the circumference.
d and a long hole 31e opened in the radial direction. 32 is a ratchet claw.

Holes 32a and 32b are formed at both ends of the ratchet pawl 32, and a pawl 32c is formed in the center. 33 is a pin,
34 is Wariwatusha.

The clutch 35 section is assembled as follows. After fitting and fixing the tip 29a of the pin 29 into the hole 28b of the clutch plate 28 and inserting the narrow diameter part 33a of the pin 33 into the long hole 31e of the locking plate 31, the narrow diameter part 33a is inserted into the ratchet pawl 3.
It is fitted and fixed into the hole 32b of No.2.

A helical spring 30 is fitted into the body 28c of the clutch plate 25, and the tip 30a is hooked onto the pin 29. Next, the torso 28
c through the circular hole 31c of the locking plate 31. At this time, the pin 29 is passed through the elongated hole 31d of the locking plate 31 and the ratchet claw 3
2, insert it into the first hole 32a, and insert the tip end 30b of the helical spring 30
is hooked onto the narrow diameter portion 33a of the pin 33. Finally, the split washer 34 is fitted onto the tip of the pin 29. The first drive shaft 13 is inserted into the center of the clutch 35 assembled in this way, and the clutch plate 28 and the drive shaft 13 are connected, and the pawl 32c is engaged with the ratchet gear 27a.

When the gear 27 is rotated in the direction of the arrow from this state, the ratchet gear 27a hooks and pulls the ratchet pawl 32, so the clutch plate 28 also rotates and the drive shaft 13 rotates.

During rotation, when claws (not shown) are fitted into the notches 28a and 31a, the clutch plate 28 and the locking plate 31
Since the ratchet gear 27 of the gear 27, which is constantly rotating in conjunction with the motor, presses the ratchet pawl 32, the ratchet pawl 32 is formed in the elongated holes 31d and 31eV.
C, the ratchet gear 27 and the ratchet pawl 32 are disengaged, and the connection between the gear 27 (i.e., the motor) and the clutch plate 28 (i.e., the drive shaft 13) is severed. At this time, even if the drive shaft 13 tries to rotate in reverse,
The above-mentioned reverse rotation prevention mechanism using the coil spring 26 works, so that the drive shaft 13 cannot rotate in the opposite direction. 3) Paper feed shaft mechanism for feeding the recording paper In FIG. 4, 36 is a fixed bearing, which is fitted in a half-moon-shaped hole 1b-3 drilled in the side plate 1b so as not to rotate. The feed shaft 37 is inserted.

Reference numeral 38 denotes a reverse rotation prevention ring, which is tightly fitted to the paper feed shaft 37 and rotates integrally therewith.

Reference numeral 39 denotes a coil spring for preventing reverse rotation, which is wound in a direction that unwinds when twisted in the direction of rotation of the paper feed shaft 37.

The fixed bearing 36 and the anti-reverse wheel 38 are provided with drum parts 36b and 38a having the same diameter.
The sides of 8a are closely spaced. A coil spring 39 is wound around these drum parts. Note that the inner diameter of the coil spring 39 is slightly smaller than the outer diameter of each drum portion. When the paper feed shaft 37 is rotating in a predetermined direction, the coil spring 39 is driven in the direction in which it is unwound, so the drum parts 36b and 38a are separated, but the paper feed shaft 37 is If the paper feed shaft 37 attempts to rotate even slightly in the opposite direction, the coil spring 39 tightens the drum portions 36b and 38a, so that they are connected, and the paper feed shaft 37 cannot be rotated in the reverse direction. A gear 40 is loosely fitted to the paper feed shaft 37, and a ratchet gear 40a is fixed to the side surface.

A clutch plate 41 rotates together with the paper feed shaft 37.

The clutch plate 41 has a hole 41a into which the narrow diameter portion 42a of the pin 42 is inserted and fixed, and a body portion 41b on the side around which the helical spring 43 is wound. Both ends of the helical spring 43 are bent outward to form tip portions 43a, 43b. 44 is a locking plate.

Five teeth 44a are provided on the outer periphery of the locking plate 44, and a circular hole 44b is provided in the center through which the paper feed shaft 37 passes. It has a long hole 44d. 45 is a ratchet claw.

Holes 45a and 45b are formed at both ends of the ratchet pawl 45, and a pawl 45c is formed in the center. 46 is a pin,
47 is Wariwassha.

The clutch 48 section is then assembled as follows.
After fitting and fixing the tip 42a of the pin 42 into the hole 41a of the clutch plate 41 and inserting the narrow diameter part 46a of the pin 46 into the long hole 44d of the locking plate 44, the narrow diameter part 46a is inserted into the ratchet pawl 45. It is fitted and fixed into the hole 45b. The helical spring 43 is fitted into the body 41b of the clutch plate 41, and the tip 43a is hooked onto the pin 42.

Next, the circular hole 44b of the locking plate 44 is inserted into the body portion 41b.

At this time, the pin 42 is inserted through the long hole 44e of the locking plate 44 and into the hole 45a of the ratchet pawl 45, and the helical spring 43
The tip portion 43b of the pin 46 is hooked onto the narrow diameter portion 46a of the pin 46.
Finally, the split washer 47 is fitted onto the tip of the pin 42. Insert the paper feed shaft 37 into the center of the clutch 48 assembled in this way, connect the clutch plate 41 to the paper feed shaft 37 with a strong fit, and attach the pawl 45 to the ratchet gear 40a.
Engage c.

A pawl 50a provided at the tip of an arm 50 fixed to a paper feed command shaft 49 pivotally supported by the side plate 1b meshes with the teeth 44a of the locking plate 44 to prevent rotation of the locking plate 44. 51A is a 1 drive motor that constantly rotates in one direction.
51 is a small gear attached to the rotating shaft 51A/ of the drive motor 51A, 52 is an intermediate gear supported on a shaft 53 attached to the side plate 1b, the gear 52a meshes with the small gear 51, and the gear 52b It meshes with the gear 40.

When the gear 40 is rotated in the direction of the arrow from this state, the ratchet gear 40a hooks and pulls the ratchet pawl 45, so the clutch plate 41 also tries to rotate, but the pawl 50a pressed by the spring hits the tooth 44a of the locking plate 44. rotation is prevented.

When the latch is applied and it tries to rotate, the ratchet pawl 45 is pushed toward the outer circumference along the long holes 44c and 44dVC of the locking plate 44 and escapes, so that the pawl 45 of the ratchet pawl 45
c and the ratchet gear 40a are disengaged, and only the gear 40 rotates without rotating the shaft 37.
Note that when the arm 50 rotates in response to a paper feed command and the engagement between the claw 50a and the tooth 44a of the locking plate 44 is temporarily disengaged, the paper feed shaft 37 is rotated by the gear 40, and the predetermined paper feed is completed. When this occurs (when the locking plate 44 rotates 1/5), the claw 50a and the tooth 44a are engaged again by the spring, and the clutch 48 prevents the rotation of the gear 40 from being transmitted to the paper feed shaft 37. The explanation of the three axes has been completed above, but when these three axes are assembled, the gear 40 supported on the paper feed shaft 37 and the gear 27 supported on the drive shaft 13 mesh with each other. The gear 27 and the gear 19 supported on the rotating shaft 6 mesh with each other, and the rotation of the pinion 51 is ultimately transmitted to the gear 19, so that they all rotate at the same time.

The side plate 1b is provided with a switching drive mechanism for switching clutches provided on the rotation shaft 6 and the drive shaft 13.

In FIG. 5, 53 is a switching plate, 54 is a drive magnet, and 55 is a tension spring. Switching plate 5
Elongated holes 53a, 53b are provided at both ends of 3 in the longitudinal direction.
A locking piece 53c is formed in the center, and a slit 53d is formed at the bottom of the elongated hole 53a. The long hole 53a is supported by the rotating shaft 6, and the long hole 53a is supported by the rotating shaft 6.
3 is supported by a drive shaft 13 so as to be movable in the left and right direction. When the switching plate 53 is located at one end, the locking piece 53c engages with the ratchet gear 23, and when the switching plate 53 is located at the other end, the locking piece 53c engages with the notch 31a (or 31b) of the locking plate 31 and the clutch plate 28. Notch 28a (or 28d
). An arm 54a is supported on the drive magnet 54, and when the coil 54b is energized, the arm 54
a is attracted against the spring 55. FIG. 6 is a side view of the printing mechanism seen from the side plate 1b.

As is clear from this drawing, the drive magnet 54 is fixed to the side plate 1b by screws 56, the tip 54a' of the arm 54a engages with the slit 53d of the switching plate 53, and the tension spring 55 is attached to the arm 54a and the side plate. The locking piece 53c is stretched between balls 57 erected on the holder 1b, and the locking piece 53c is engaged with the clutch plate 28 and the locking plate 31 when the magnet 54 is not activated. FIG. 7 is an exploded perspective view showing the mechanism on the side plate 1a side. In the figure, reference numeral 58 denotes a locking arm, which is supported on the rotating shaft 6 and can rotate independently of the rotation of the rotating shaft 6.

A helical spring 59 always applies a rotational force in the direction of the arrow. A claw 58a is formed at the tip of the locking arm 58, and a protrusion 58b is formed in the middle. 70 is a rotary encoder fixed to the rotating shaft 6.

60 is a feed pawl fixed to the drive shaft 13, which includes two pawls 60a, 60b and a sharp pawl 60c, 60d (
(partially not shown) is provided.

61 is a pentagonal cam body that is fixed to the paper feed shaft 37 and rotates together with it; 62 is a pentagonal cam body that is supported on the paper feed shaft 37;
It is a take-up gear that can be separated from the cough paper feed shaft 37 and rotated freely.

The take-up gear 62 is formed with a gear 62a and a ratchet gear 62b, and some of the teeth of the gear 62a are cut out by several pitches to form a tooth-missing portion 62c. Further, a drum portion 62d is formed between the ratchet gear 62b and the gear 62a, and a shift wire (or thread) connected to the carriage 3 is connected to the drum portion 62d.
8 is wound. A release arm 63 is rotatably supported on a shaft 64 provided on the side plate 1a.

The release arm 63 has two cam valleys 63a, 63b and one cam peak 63c, and has a protrusion 63d below the cam valley.
Reference numeral 65 designates an engaging arm fixed to the paper feed command shaft 49, and has a slit 65a formed at its tip.

Reference numeral 66 denotes a guide pole provided upright on the side plate 1a, the tip of which is fitted into a slit (not shown) provided on the back side of the winding gear 62 to determine the initial position of the winding gear. This is a fixed stopper member. When these parts arranged on the side plate 1a side are assembled and the carriage 3 is in the initial position, the protrusion 58b of the locking arm 58 fits into the cam valley 63a of the release arm 63, and the claw 58a at the tip is engaged. It is kept away from the ratchet gear 62b, and the take-up gear 62
is in a free state.

Further, the protrusion 63d of the release arm 63 is in contact with the flat surface of the cam body 61. FIG. 8 is a side view of the printing mechanism seen from the side plate 1a side. As is clear from this drawing, the engaging arm 6
The L-shaped operating arm 6 of a magnet 67 is energized when a command to wind up the printing paper is issued.
The tip 67b of 7a is loosely fitted. 68 is a terminal plate that holds a contact piece 69 that comes into contact with the rotary encoder 70.

Next, a series of printing operations in the printing mechanism according to the present invention will be explained.

Carriage 3 force - As shown in Fig. 1, when the motor starts rotating in response to a printing command from the rightmost position, that is, the initial position, the gears 19 and 27 provided in the three shaft mechanisms as described above are activated. , 40 all rotate.

Since the clutch 21A connected to the gear 19 is in a connected state, the ratchet gear 23 and the rotating shaft 6 rotate.
Therefore, the rotary encoder 70 and the type wheels 4, 5 are also rotating. When the desired function type character comes to the printing position, the drive magnet 54 (FIG. 6) is energized and the switching plate 53 is moved to the left in FIG.

Therefore, the locking piece 53c of the switching plate 53 meshes with the ratchet gear 23 to stop it. Note that FIGS. 9a and 9b are cross-sectional views showing the state before and after the switching plate 53 is switched. When the ratchet gear 23 is stopped, the clutch 21A of the rotating shaft 6 is disengaged, and the rotating shaft 6 is stopped, and only the gear 19 rotates, as described above. On the other hand, when the switching plate 53 moves, this locking plate 53c
(Fig. 3) and comes off from the notches 28a, 31a (Fig. 9a).

Therefore, the clutch 35 is in a connected state, and the drive shaft 1
3 rotates, and during its initial rotation, the marker cam 12 presses the printing marker 11 (FIG. 1) to print a function symbol. When the drive shaft 13 further rotates, the feed pawl 60 rotates in the direction of the arrow in FIG.
c (or 60d) rotates the distal end 63e of the release arm 63 in the direction of the arrow, that is, downward, so that the protrusion 58b of the locking arm 58 falls into the cam valley 63b.

As a result, the locking arm 58 rotates in the direction of the arrow in FIG. 7, engages the pawl 58a with the ratchet gear 62b, and
2. Prevents reversal. Note that from this point on, the claws 60c, 60d and the release arm 63 cannot come into contact with each other until the carriage returns. When the feed pawl 60 continues to rotate, the pawl 60b, which is out of phase with the sharp pawl, meshes with the gear 62a, causing the take-up gear 62 to rotate. When this rotates, the shift wire 8 is wound around the drum portion 62d, and the carriage 3
is shifted. The above series of operations is performed by half a rotation of the drive shaft 13. During this time, the attachment of the drive magnet 54 is released, so the switching plate 53 is moved to the sixth position by the tension spring 55.
After moving to the right in the figure and the drive shaft 13 making a half turn, the clutch 3
5, and disengages from the ratchet gear 23. As a result, the clutch 21A is in a connected state and the clutch 35 is in a disengaged state, so that the rotary shaft 6 rotates and the type wheels 4 and 5 begin to rotate, while the drive shaft 13 stops. When the desired number to be printed on the second digit comes to the printing position, the drive magnet 54 is turned on again.
is excited, and the switching plate 53 is moved to the left again in FIG. Therefore, the locking piece 53c of the switching plate 53 meshes with the ratchet gear 23 to stop it. When the ratchet gear 23 is stopped, the clutch 2 of the rotating shaft 6
1A is cut, the rotating shaft 6 stops, and the gear 19 idles.
On the other hand, when the switching plate 53 moves, the locking pieces 53c are removed from the notches 28b and 31d of the clutch 35.

Therefore, the clutch 35 becomes connected and the drive shaft 13
rotates, and the hammer cam 12 presses the printing mark 11 to print the desired number. When the drive shaft 13 rotates,
In FIG. 7, the feed pawl 60 rotates in the direction of the arrow, and the pawl 6
0a (or 60b) meshes with the gear 62a and rotates the take-up gear 62 by one tooth in the same manner as described above. When this rotates, the shift wire 8 is wound around the drum portion 62d, and the carriage 3 is shifted by one more digit against the aforementioned tension spring 7. When the feed pawl 60 rotates half a turn, the pawl 60a and the gear 62a are disengaged, and the single digit feed operation is completed. During this time, the excitation of the drive magnet 54 is released, so that the switching plate 53 is activated by the tension spring 55. After the drive shaft 13 moves to the right in FIG.
) and disengages from the ratchet gear 23. Therefore, the clutch 21A becomes connected, and the clutch 3
5 is in an uncoupled state, the rotating shaft 6 rotates, and the type wheels 4,
5 begins to rotate, the drive shaft 13 stops, and the printing operation of the second digit number is completed. This printing operation is repeated several times to print the desired number of digits, and when one line of printing is completed, the magnet 67 (Fig. 8) is energized and the actuating arm 67a is moved clockwise. Rotate.

Therefore, the engaging arm 65 is raised against the spring 71 and rotates counterclockwise, thereby rotating the paper feed command shaft 49.
Therefore, the arm 5 on the side plate 1b side that rotates integrally with the shaft 49
0 rotates, and as shown in FIG.
As shown in FIG. 11, the pawl 50a that had been engaged with the clutch 48 is temporarily disengaged from the teeth 44a of the locking plate 44, and the clutch 48 is brought into a connected state. Therefore, the paper feed shaft 37 begins to rotate and feeds the recording paper 14 by a predetermined pitch. Paper feed shaft 37
When the cam body 61 (Fig. 7) starts rotating, the cam body 61 (Fig. 7), which rotates integrally with the cam body 61, also starts rotating, as shown in Fig. 12.
1 pushes up the protrusion 63d of the release arm 63.

This action causes the protrusion 58b of the locking arm 58 to be moved into the cam valley 6.
3b to 63a to disengage the pawl 58a from the ratchet gear 62b. Therefore, the take-up gear 62 becomes free. Note that when the protrusion 58b of the locking arm 58 is engaged with the valley 63b of the release arm 63, both 58 and 63 maintain a mechanically balanced state, and are released by the sharp claws 60c and 60d of the feed claw 60 mentioned above. This state is maintained until the arm 63 is pushed downward. In other words, attempts are being made to ensure carriage return. When the gear 62 becomes free, the carriage 3 is constantly pulled in the direction of the initial position by the tension spring 7, so it quickly returns to the initial position while pulling the shift wire 8. The shift wire 8 then rotates the take-up gear 62 to return it to its initial position. As explained in detail above, according to the present invention, only one
The motors can be kept rotating in a constant direction at all times, and the rotational force can be switched by three clutches to select type, print, drive the printer, and feed the paper. There is no need to provide an electromagnetic plunger for printing operation outside the drive motor, or a mechanism for rotating the drive motor forward or reverse.

Therefore, the present invention can be made smaller than conventional devices, and printing speed can also be improved compared to conventional devices.

[Brief explanation of the drawing]

Figure 1 is a plan view of the printing device, Figure 2 is an exploded perspective view of the rotating shaft mechanism that rotates the type wheel, Figure 3 is an exploded perspective view of the drive shaft mechanism that drives the printing hammer cam, and Figure 4 is an exploded perspective view of the drive shaft mechanism that drives the printing hammer cam. Figure 5 is an exploded perspective view of the paper feed drive shaft mechanism, Figure 5 is an exploded perspective view of the two-shaft mechanism for rotating the print hammer and type wheel, Figure 6 is a right side view, Figure 7 is
The figure is an exploded perspective view of the main part showing the mechanism on the left side, Figure 8 is a left side view, Figures 9a and b are sectional views showing the operating state of the clutch part, and Figures 10 and 11 are the clutch operating part. FIG. 12 is an exploded perspective view showing the mechanism for releasing the carriage. In the figure, 1 is a frame, 3 is a carriage, 4 and 5 are type wheels,
6 is a rotating shaft, 7 is a tension spring, 8 is a shift wire, 11
1 is a printing hammer, 13 is a drive shaft, 15 is a stopper disc, 1
7 is a reverse rotation prevention wheel, 18 is a coil spring, 19 is a gear, 20
is a holding cylinder, 21 is a cylindrical body, 21A is a clutch, 22 is a coil spring, 23 is a ratchet gear, 25 is a reverse rotation prevention wheel,
26 is a coil spring, 27 is a gear, 28 is a clutch plate, 2
9 is a pin, 30 is a helical spring, 31 is a locking plate, 32 is a ratchet claw, 33 is a pin, 35 is a clutch, 37 is a paper feed shaft, 38 is a reversal prevention ring, 39 is a coil spring, 40 is a gear, 41 is a clutch plate, 42 is a pin, 43 is a helical spring, 4
4 is a locking plate, 45 is a ratchet pawl, 46 is a pin, 48 is a clutch, 49 is a paper feed command shaft, 50 is an arm, 51 is a small gear, 51A is a 1 drive motor, 52 is an intermediate gear, 5
3 is a switching plate, 54 is a drive magnet, 55 is a bow tension spring, 56 is a screw, 57 is a pole, 58 is a locking arm, 59
60 is a helical spring, 60 is a feed pawl, 61 is a cam body, 62 is a winding gear, 63 is a release arm, 64 is a shaft, 65 is a locking arm, 66 is a guide pole, 67 is a magnet, 68 is a terminal plate, 69
is a contact piece, and 70 is a rotary encoder.

Claims (1)

[Claims] 1. A motor that rotates only in one direction, a rotating shaft of the type wheel that rotates integrally with the type wheel, a printing hammer that strikes the type wheel through the recording paper, and a drive shaft to which a hammer cam that drives the printing hammer is attached. and a paper feed shaft for feeding the paper,
a gear train that constantly connects the motor with the rotary shaft, the drive shaft, and the paper feed shaft; a first clutch means that controls rotational transmission between the gear on the rotary shaft and the rotary shaft; and the drive shaft. a second clutch means for controlling rotational transmission between the gear on the upper gear and the drive shaft, and a third clutch means for controlling rotational transmission between the gear on the paper feeding shaft and the paper feeding shaft, A printing device characterized in that, by selectively controlling the first, second, and third clutch means, the unidirectional rotating motor selects type, drives a print hammer, and feeds paper.