JPS6353955B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, particularly an ultra-small serial printer capable of alphanumeric printing, and aims to reduce the number of driving sources and simplify the mechanism.

Recent calculators have become more multifunctional and sophisticated, and there are many types of input keys, such as scientific calculators and program calculators. Therefore, as a printing device built into this type of calculator, it is desired to develop a printing device that is capable of alphanumeric printing and also prints in a matrix format because the printed data is clear.

The present invention has been made in view of these points,
Examples will be described below with reference to figures.

FIG. 1 is a diagram for explaining the schematic configuration of a printing device. Between the side plates 1a and 1b, which are part of the frame of the printing device, a type wheel selection cam shaft 2, a type shaft 3, a print/carry shaft 4, and a rack 5 are installed in order from the front side as viewed in the figure. It is rotatably constructed at intervals of
Below the carry shaft 4 is a paper feed shaft 6 (see Figure 2).
is installed so that it can rotate.

The carriage 7, which is stretched between the type wheel selection cam shaft 2 and the type shaft 3, is held so as to be able to slide along these axial directions, and is moved to a home position (close to the side frame 1a) by a carriage return spring 8. It is always elastically biased towards the starting position). Inside the carriage 7, a slider frame 11, which is spanned between the type wheel selection camshaft 2 and the type shaft 3, is arranged so as to be slidable in the axial direction like the carriage 7. Inside the slider frame 11, a type wheel group (type carrier) 10 consisting of four type wheels 9a to 9d connected by splines to the type shaft 3 and a type wheel selection cam spline connected to the type wheel selection cam shaft 2 are provided. 12 is retained. A type ring group return spring 13 loosely fitted to the type shaft 3 between the carriage 7 and the slider frame 11 causes the type ring group 10 and the type wheel selection cam 12 to be directed to the reference position on the side plate 1a side via the slider frame 11. is always pressed.

Since the type wheel selection cam 12 is spline-coupled to the type wheel selection cam shaft 2 as described above, it can rotate integrally with the shaft 2 and slide along the axial direction. is cam groove 1
4 is formed. As shown in the developed view of the cam surface of the type wheel selection cam 12 in FIG. 3, the cam groove 14 is composed of a deformed spiral feed cam groove 14a and a return cam groove 14b bent in the middle. Both cam grooves 14a and 14b are in communication, and the feed cam groove 14a extends over 3/4 of the circumferential direction (0° to 270°) of the type wheel selection cam 12, while the return cam groove 14b extends over the type wheel selection cam 12. 1/ of the circumferential direction of the wheel selection cam 12
Each section is provided over 4 sections (270° to 360°).

As shown in FIG. 1, the carriage 7 is provided with a protrusion 15 that fits into the cam groove 14 of the type wheel selection cam 12, and when the type wheel selection cam 12 is rotated, the protrusion 15
5 and the pressing force of the type wheel group return spring 13, the slider frame 11 holding the type wheel group 10 and the type wheel selection cam 12 moves in the left-right direction within the carriage 7.

That is, in the initial state, the slider frame 11 is pushed to the innermost side of the carriage 7 by the pressing force of the type ring group return spring 13, and the protrusion 15 is pushed to the innermost side of the carriage 7.
As shown in the figure, it engages with the cam groove 14 at a position on the tip end side of the feed cam groove 14a. In this state,
The first type wheel 9a faces a hammer 16 in a hammer/carry cam holder 19 supported by the print/carry shaft 4 with a paper 17 interposed therebetween. The position where the first type wheel 9a faces the hammer 16 in this manner is referred to as the reference position of the type wheel group 10 (see FIG. 1).

Next, when the type wheel selection cam 12 is rotated 90 degrees in the direction of arrow A shown in FIG. 3 using the type wheel selection cam shaft 2,
Guided by the protrusion 15 that is fixed to the type wheel selection cam 12, the slider frame 11 compresses the type ring group return spring 13 and moves toward arrow B shown in FIG.
The second type wheel 9b is now opposed to the hammer 16 after being shifted by a predetermined amount (one pitch) to the right in FIG. When the type wheel selection cam 12 is further rotated 90 degrees in the direction of arrow A, the type wheel group 10, slider frame 11, and type wheel selection cam 12 are all shifted to the right by a predetermined amount in the same way as described above, and the third The type ring 9c faces the hammer 16. Furthermore, by rotating the type wheel selection cam 12 by 90 degrees in the direction of arrow A, that is, by rotating the type wheel selection cam 12 by 270 degrees from the start of rotation, the type wheel group 10 is shifted to the fourth type wheel. 9d can be opposed to the hammer 16.
Such feeding of the type wheel group 10 is performed while the protrusion 15 is sliding within the feed cam groove 14a of the type wheel selection cam 12, and therefore it is difficult to decide which type wheel 9 should face the hammer 16. can be selected by adjusting the rotation angle of the type wheel selection cam 12 (type wheel selection cam shaft 2).

From the state where the fourth type wheel 9d is facing the hammer 16, the type wheel selection cam 12 is further moved by the arrow A.
When rotated in the direction, the protrusion 15 moves into the feed cam groove 14a.
Then, it moves to the return cam groove 14b. Return cam groove 14b
Since the direction is opposite to that of the feed cam groove 14a, by rotating the type wheel selection cam 12 by 90 degrees in the direction of arrow A, the protrusion 15 returns to the tip of the feed cam groove 14a. That is, as the protrusion 15 slides within the return cam groove 14, the assembly of the type wheel group 10, slider frame 11, and type wheel selection cam 12 returns, and the first type ring 9a moves into the hammer 16.
and face each other again. Since the type wheel selection cam shaft 2 (type wheel selection cam 12) rotates only in a fixed direction, the feeding and return of the type wheel group 10 are repeated alternately.
In the meantime, the selection of the type wheel 9 takes place.

As shown in FIG. 1, a type wheel position sensor 18 is fixed to the left end of the type wheel selection camshaft 2, which detects which type wheel 9 is currently facing the hammer 16 and the position of the type wheel 9. A condition is detected. Further, as shown in FIG. 1, a type position sensor 25 and a type reference position sensor 26 are fixed to the right end of the type wheel 3.

As shown in FIG. 1, a hammer/carry cam holder 19 is slidably held on the print/carry shaft 4, and a hammer 16 and a carry cam 20 are arranged inside the hammer/carry cam holder 19. The carry cam 20 is splined to the print/carry shaft 4 and its type ring group 10
A hammer 16 is extrudably held on the side opposite to.

As shown in FIGS. 4, 5, and 6, the carry cam 20 has two protrusions 2 on its outer circumference at 180° intervals.
1 is formed. This protrusion 21 includes a circumferential protrusion 21a extending in the circumferential direction provided over approximately 1/4 of the circumferential direction of the carry cam 20, and a circumferential protrusion 21a provided over approximately 1/4 of the circumferential direction of the carry cam 20. The protrusions 21a and 21b are continuous. The protrusion 21 of the carry cam 20 is designed to mesh with rack teeth 22 provided on the rack 5, as shown in FIG. The rack tooth 22 is the seventh
As shown in the drawings and FIG. 8, the racks have a truncated conical shape and are arranged in rows at equal intervals along the longitudinal direction of the racks 5.

As shown in FIG. 1, the carriage 7 is connected to a hammer/carry cam holder 19 by a rope (string body) 24 stretched through six rollers 23a to 23f. Therefore, the carriage 7
are adapted to move in the same direction and by the same amount in synchronization with the hammer/carry cam holder 19.
As mentioned above, the carriage 7 is always urged toward the home position by the carriage return spring 8, so the protrusion 2 of the carry cam 20 is normally biased by this influence.
1 meshes with the rack teeth 22 in an elastic manner.
Then, when the print/carry shaft 4 (carry cam 20) is rotated 1/4 in the direction of arrow C as shown in FIG.
At first, the rack teeth 22 are in sliding contact with the circumferential protrusion 21a, so the carry cam 20 does not move and only rotates 1/4 of a turn on the spot. Continue printing/
Move the carry shaft 4 (carry cam 20) 1/1 in the direction of arrow C.
After four rotations, the next rack tooth 22 that was in contact with the circumferential protrusion 21a,
The spiral protrusion 21b of the other protrusion 21 comes into sliding contact, and as it rotates, the carry cam 20 moves toward the side plate 1b by an amount equivalent to one digit, that is, in the direction of arrow D in FIGS. 1 and 6. Move to.

The hammer 16 is arranged together with a carry cam 20 in a holding body 19, while the carriage 7 is connected to the holding body 19 via a rope 24.
Therefore, the carry cam 20 is moved by an arrow D corresponding to one digit.
When moving in this direction, the carriage 7 is thereby also transported in the same direction as the hammer 16 by the same amount.

As shown in FIG. 1, the rotational force of the motor 27, which always rotates in one direction, is applied to the type shaft 3 and the type wheel selection camshaft 2 via the type selection clutch 28, and to the print/carry clutch 30 for printing.・Transmitted to the carry shaft 4 respectively. Type selection clutch 28
The rotational transmission between the print/carry clutch 30 and the print/carry clutch 30 is appropriately switched by a switching member 31, which is driven by an electromagnet 33.

If both the clutches 28 and 30 are in a state in which rotation transmission is possible and OFF in a state in which rotation transmission is not possible, then when clutch 28 is ON, clutch 30 is OFF, and when clutch 28 is OFF, clutch 30 is ON. , both clutches 2
8 and 30 are set to be turned on alternatively.

Next, the construction of each clutch and other parts related thereto will be explained with reference to FIG.

The type shaft 3 incorporates a type wheel group 10, a type selection clutch 28, and a timing cam body 35, respectively.

The type selection clutch 28 includes a drive side gear 37 having a cylindrical portion 36 protruding from the center of one side, a spring fixing ring 38, a type position selection ratchet 39, a coil spring 40, and a type side release cam 42. At the center of one side of the cam 42 is an annular portion 4 into which the cylindrical portion 36 is fitted.
1, and the other side has teeth 5 only on a part of the outer periphery.
2a are integrally formed.

One end 40a of the coil spring 40 is fitted into a locking groove 38a of the spring fixing ring 38, and the other end 40b is fitted and locked into a locking groove 41a provided in an annular portion 41 of a type side release cam 42, respectively. and,
With the coil spring 40 tightly wound around the cylindrical portion 36 of the drive side gear 37, the cylindrical portion 36 is inserted into the center hole of the spring fixing ring 38 and into the ratchet 39.
The drive side gear 37 loosely fitted to the type shaft 3 is inserted into the center hole of the annular part 41 of the release cam 42.
A spring clutch is formed between the release cam 42 and the release cam 42.

That is, the fan-shaped protrusion 41b provided on the annular portion 41 of the release cam 42 engages with a fan-shaped notch (not shown) provided on the side surface of the ratchet 39 (however, the fan-shaped protrusion and the notch are There is a small gap corresponding to the so-called loosening angle of the spring in the direction of rotation), and the cylindrical portion of the spring fixing ring 38 is tightly fitted into the center hole of the ratchet 39, and the three members 38, 39, and 42 are integrated as a driven side. The driven side is the driving side of the clutch, which is the driving gear 37 and the coil spring 4.
Connected via 0. And Ratchet 39
When the locking member is not inserted into the coil spring 40, the coil spring 40 is tightened and the drive side and the driven side rotate together. However, when the ratchet 39 is prevented from rotating, the coil spring 40 immediately loosens and the drive side rotates together. The configuration is such that rotation cannot be transmitted to the driven side.

The number of teeth of the type position selection ratchet 39 corresponds to the number of type portions 44 (including blank portions) provided on the outer periphery of the type ring 9. The type side release cam 42 is press-fitted into the type shaft 3 and rotates integrally therewith, and a type side release groove 45 is formed at one location on the circumferential cam surface provided on the outer periphery. A plurality of so-called blank parts without printed characters are provided on the outer circumference of the type ring 9 in the type part 44, and the region of the release groove 45 in the release cam 42 corresponds to one of the blank parts.

The timing cam body 35 is attached to the type shaft 3 so as to be rotatable separately from the type shaft 3, and the timing cam body 35 is attached to the gear 54 of the intermittent rotating gear body 55 fixed to the type wheel selection cam shaft 2. The timing cam body 35 rotates as the intermittent rotating gear body 55 rotates. The number of teeth of the gear 47 and the gear 54 are set equal (both 47 and 54).
4 is a spur gear), so when the gear 54 of the intermittent rotating gear body 55 (type wheel selection cam shaft 2) rotates 1/4, the timing cam body 35 also rotates 1/4. In addition, 50
A is a type wheel shift side release groove provided on the outer periphery of the type wheel shift side release cam 50, and corresponds to a predetermined shift position of the type wheel group 10.

The intermittent rotating gear body 55 includes a gear 54 that meshes with the gear 47 of the timing cam body 35, and an intermittent gear 53 that engages with the intermittent gear 52 of the type side release cam 42 (the driven side of the type selection clutch 28). Both 53 and 54, which are integrally molded, rotate together with the type wheel selection camshaft 2. The intermittent gear 53 has four tooth portions 53a and 4 on its outer periphery.
The concave circular arc portions 53b are alternately formed at equal intervals, and the partially toothed gear 52 (i.e., the type selection clutch 28
(driven side) rotates once, its tooth portion 52a meshes with one of the tooth portions 53a, and the intermittent rotating gear body 55 rotates 1/4. Then, the intermittent rotating gear body 55 is 1/4
When it rotates, the type wheel selection cam shaft 2 and the type wheel selection cam 12, which rotate together with this, rotate by 1/4, and the aforementioned type wheel group 10 is transferred by 1 pitch, and the timing cam body 35 is also rotated by 1 pitch. /4 rotations. Further, when the type selection clutch 28 is turned OFF and the partially toothed gear 52 on the driven side has stopped rotating, in other words, when the rotation stop position of the type wheel group 10, which will be described later, is selected, as shown in FIG. As shown in FIG. 2, the concave arc portion 53b of the intermittent gear 53 and the arcuate outer periphery 52b of the intermittent gear 52 are in an engaged state, and the intermittent gear 53 is unable to rotate. For this reason, a blank portion is formed on the outer periphery of the type ring group 10 corresponding to the tooth portion 52a of the partially toothed gear 52, and only when this blank portion faces the hammer 16, the tooth portion 52a and the tooth portion 53a are connected to each other. are starting to mesh together.

The print/carry clutch 30 built into the print/carry shaft 4 has a ratchet 57 at the center of one side.
a drive-side gear 58 protruding from the ratchet 5;
7, a print/carry control plate 60, and a control lever lock body 61. The drive side gear 58 and the print/carry control plate 60 are held on the print/carry shaft 4 so as to be rotatable independently from the shaft 4, and only the control lever lock body 61 is connected to the print/carry shaft. It is attached so that it rotates together with 4. The print/carry clutch 30 is a so-called pawl clutch, in which a pin protruding from the side surface of the control lever lock body 61 passes through a through hole in the print/carry control plate 60 and connects to a small hole that is the center of rotation of the locking pawl 59. They are fitted and fixed, and the pin at the tip of the locking claw 59 is held in the other through hole of the control plate 60 so that it does not fall out.
0 and 61 are designed to rotate as one. In addition, a spring provided at the middle of the locking pawl 59 is connected to the drive side by a spring whose one end is locked to the pin of the locking pawl 59 and the other end is locked to the other pin of the control lever lock body 61. It is in elastic contact with a ratchet 57 that is integral with a gear 58. Therefore, when the locking member (switching member 31), which will be described later, is not fitted into the notch 62 of the driven side print/carry control board 60, the rotation of the driving side gear 58 is caused by the engagement engaged with the ratchet 57. The driven side of the clutch (members 60, 61
On the other hand, when the locking member is fitted into the notch 62 of the control plate 60 to prevent rotation, the locking pawl 59 that has been engaged with the ratchet 57 is released from the ratchet 57 against the spring force. However, transmission between the driving side and the driven side becomes impossible. That is, the print/carry control board 60
ON/OFF of the clutch is determined by whether or not a locking member, which will be described later, fits into the notch 62 on the outer periphery.

On the circumferential cam surface of the print/carry control board 60,
Two notches 62 are provided at 180° intervals.
On the outer periphery of the control lever lock body 61, one raised tooth portion 63 is provided at an interval of 180°, and further, on the downstream side of the raised tooth portion 63 in the rotational direction, an arc-shaped lock is provided at a slight interval. A portion 64 is formed respectively. The outer periphery of the lock portion 64 matches the tip circle of the raised tooth portion 63, and the outer peripheral portions other than the raised tooth portion 63 and the lock portion 64 are stepped down from these. It matches the root circle.

This control lever lock body 61 is adapted to engage with a carriage pattern/paper feed control lever 65 loosely fitted onto the paper feed shaft 6. The control lever 65 includes a lever body 66 that is rotatably supported by the paper feed shaft 6, a paper feed shaft drive ratchet 67 that is inserted into the hollow part of the lever body 66 and rotates integrally with the paper feed shaft 6, and a pawl. Piece 68 and biasing spring 69
and a support pin 70.

The lever main body 66 mainly consists of a first lever piece 66a and a second lever piece 66b that have substantially the same shape, and both lever pieces 66a and 66b are integrally molded with a predetermined interval in between. There is. Second
As shown in FIGS. 9, 10, and 11, a through hole 71 into which the paper feed shaft 6 is loosely fitted is formed at the center of rotation of both lever pieces 66a, 66b.

Control lever lock body 61 of first lever piece 66a
A fitting surface 72 of a circular concave portion having the same radius of curvature as the outer periphery of the lock portion 64 of the control lever lock body 61 is provided on the side surface facing the control lever lock body 61. As shown in FIG. 3, the lock portion 64 is fitted into the fitting surface 72. Further, a sliding contact surface 74a is provided on the tip surface of the free end 73a of the first lever piece 66a, and is an arcuate recessed portion having the same radius of curvature as the outer periphery of the print side release cam 42, as shown in FIG. As the print side release cam 42 rotates, its outer cam surface and the sliding surface 74a come into sliding contact.

Moreover, the free end 73 of the second lever piece 66b
A sliding contact surface 74b is provided on the tip surface of b, which is an arcuate concave portion having the same radius of curvature as the outer periphery of the type wheel shift side release cam 50, and as shown in FIG. As the cam 50 rotates, its outer cam surface and the sliding contact surface 74b come into sliding contact.

As shown in FIGS. 12 and 13, a tubular portion 76 having a wide-angle notch 75 is provided in a protruding manner at the center of the outer peripheral surface of the second lever piece 66b, and the notch 75 has a lug which will be described later. The engagement protrusion 78 of the release transmission body 77 is inserted. A pin 79 is provided protruding from the outer surface of the second lever piece 66b, and the pin 79 is connected to the spring 1.
By elastically pressing downward at 01, the carriage return/paper feed control lever 65 moves to the 9th position.
In the figure, it is biased clockwise.

As shown in FIGS. 2, 9 to 13, insertion holes 80 into which the support pins 70 are inserted are bored at the free ends 73a and 73b of the first lever piece 66a and the second lever piece 66b, respectively. It is set up.
The claw piece 68 is rotatably supported by the support pin 70 inserted therein, and the tip of the claw piece 68 engages with the teeth of the paper feed shaft driving ratchet 67, and the claw piece 68
is elastically biased by a biasing spring 69 in a direction in which it always engages with the ratchet 67.

The lock release transmitting body 77 is shown in FIGS. 2 and 1.
As shown in FIG. 4, it mainly consists of an annular part 81 and a gear part 82, the above-mentioned engagement protrusion 78 is provided on the side surface of the annular part 81, and a stopper 83 protrudes in a substantially tangential direction of the gear part 82. It is set up. This lock release transmission body 77 is loosely fitted to the paper feed shaft 6, and
By inserting the engaging protrusion 78 into the notch 75 of the lever 65, it is partially engaged with the carriage return/paper feed control lever 65 (12th and 13th).
(see figure).

The gear portion 82 of the rack release transmission body 77 meshes with an idler gear 84 shown in FIG.

As shown in FIG. 2, the switching member 31 is composed of a pressing lever 86 and a claw member 87. The base of the pressing lever 86 is rotatably supported,
The claw portion 86a on the free end side is in elastic contact with the circumferential cam surface of the print/carry control plate 60 by a spring means (not shown). An engagement groove 88 is formed at the free end of the pressing lever 86, into which a connecting pin 89 of the claw member 87 is inserted. The pawl member 87 is rotatably supported at its intermediate portion, has the connecting pin 89 formed at one end, and a locking pawl 90 that engages with the teeth of the type position selection ratchet 39 at the other end. ing.

As shown in FIG. 1, a rack return member 93 spline-coupled to the print/carry shaft 4 is held near the inner surface of the side plate 1a of the print/carry shaft 4. As shown in FIGS. 2 and 15, two push teeth 94 are provided on the outer periphery of the rack 5 at an interval of 180°, and on the outer periphery of the end of the rack 5 there is a single push tooth 94 that can be engaged with the push teeth 94. Two receiving teeth 95 are provided protrudingly. As shown in FIG. 2, only when the hammer 16 and the carry cam 20 return to their home positions are they pressed in the upper right direction in FIG. The pushing tooth 94 is pressed in the direction of the receiving tooth 9 of the rack 5.
It is now facing 5.

Next, the operating order of this printing device will be explained.

When printing for one line is started, the carriage 7 is held at the home position by the carriage return spring 8, as shown in FIG. Waiting at the standard position. In this standby state, the motor 27 begins to rotate based on a print command for one line from a control section (not shown). In the initial state, since the electromagnet 33 is not energized, the switching member 31 engages with the notch 62 of the print/carry control board 60, and the character position selection ratchet 39 is not engaged with the switching member 31. Therefore, the print/carry clutch 30 is OFF, and the type selection clutch 28 is OFF.
The power of the motor 27 is in the ON state, and the power of the motor 27 is transmitted through the type shaft 3 and the intermittent gear 52 on the type shaft 3 to the intermittent rotation gear body 55 (type wheel selection camshaft 2) and the intermittent rotation gear body 55. The signal is transmitted to the timing cam 35 via the timing cam 35. As the type shaft 3 rotates, the type wheel group 10 rotates, and an ink roller (not shown) mounted on the carriage 7 applies ink to the outer periphery of each of the type wheels 9a to 9d.

Note that before the motor 27 rotates, the rack 5 is rotated slightly clockwise as shown in FIG. Since the rack 5 and the carry cam 20 are separated, the rack 5 and the carry cam 20 are in a non-engaging state, and the receiving tooth 95 faces the rack return member 93.

When the type wheel 3 rotates as described above, the type position sensor 25 outputs a type position detection signal, and the type reference position sensor 26 outputs a type reference position signal. When the type shaft 3 continues to rotate, a type reference position signal is periodically output, and a type position detection signal is continuously output until the next type reference position signal is output. The number of printed parts (including blank parts) corresponds to the number of printed parts (including blank parts).

On the other hand, based on the intermittent rotation of the type shaft selection camshaft 2, a type wheel reference position detection signal and a type wheel position detection signal are output from the type wheel reference position sensor (not shown) and the type wheel position sensor 18, which rotate integrally therewith. be done.

Further, the type wheel selection cam 12 rotates together with the type wheel selection cam shaft 2, so that the type wheel group 10 is gradually shifted in the direction of arrow D against the elasticity of the type wheel group return spring 13 (the first (see figure),
The type wheel 9 facing the hammer 16 changes sequentially.

By rotating the type wheel selection camshaft 2 and the type shaft 3, shift selection of the type wheel 9 holding the desired type to be printed and rotation selection of the desired type on the type wheel 9 are performed. The order of the shift selection of the type wheel 9 (selection of the sliding position in the direction of arrow D) and the selection of the type, that is, the selection of the rotation stop position of the type wheel group 10, is such that the rotation stop position selection is always performed after the shift selection. It's becoming like that.

That is, based on the printing command, the above-mentioned intermittent rotation transmission mechanism selects a one-pitch shift for each rotation of the type wheel group 10 until the type wheel having the desired type faces the hammer 16, and this shift is performed by the intermittent rotation transmission mechanism. The electromagnet 33 is energized during one revolution of the type wheel group 10 following completion of selection. As a result, the switching member 31 rotates against the elasticity of the biasing spring, moves away from the print/carry control plate 60, and becomes disengaged.
9.

Therefore, the type selection clutch 28 is turned OFF, the print/carry clutch 30 is turned ON, and the desired type is stopped facing the hammer 16. This excitation of the electromagnet 33 is instantaneous, and during this time the engagement between the print/carry control board 60 and the switching member 31 is released, and then the print/carry operation begins.

When the switching member 31 leaves the notch 62 of the print/carry control board 60, the print/carry control board 60,
The control lever lock 61, the print/carry shaft 4 engaged with the control lever lock 61, the rack return member 93 splined to the print/carry shaft 4, and the carry cam 20 rotate.
When the electromagnet 33 is de-energized after the rotation starts, one end of the switching member 31 comes into elastic contact with the circumferential cam surface of the print/carry control board 60 due to the restoring force of the biasing spring. The rotation of the control plate 60, print/carry shaft 4, etc. is not prevented by the switching member 31 until the rotation is made half a rotation.

At the initial stage of rotation of the rack return member 93,
Push teeth 9 provided therein as shown in FIG.
4, push the receiving tooth 95 of the rack 5 in the direction of arrow E. As a result, the rack teeth 22 that have fallen down until now are returned to the position facing the carry cam 20, and the rack teeth 22 mesh with the protrusions 21 of the carry cam 20. As a result, the shift canceling operation is completed, and the shift becomes possible.

In addition, the carry cam 20 also rotates synchronously, but as mentioned above, the first 1/4 rotation
Since 1a is in sliding contact with the rack teeth 22, the carry cam 20 does not move and rotates on the spot. As shown in FIGS. 2, 4, and 5, two hammer push-out protrusions 96 are provided on both end surfaces of the carry cam 20 at an interval of 180 degrees. Therefore, during the first quarter rotation of the carry cam 20, the hammer 16 is pushed out by the hammer pushing protrusion 96 toward the type wheel 9 against the elasticity of the hammer return spring (not shown), and the paper 17 is pressed against the type portion facing the hammer 16 to print.

With the subsequent 1/4 rotation of the carry cam 20, the hammer pushing protrusion 96 separates from the hammer 16, and the hammer 1
6 returns to its original position by the restoring force of the hammer return spring.
At the same time, the helical protrusion 21b of the carry cam 20 comes into sliding contact with the rack teeth 22, and the carry cam 20
As the hammer/carry cam holder 1 rotates,
9 is moved in the direction of arrow D in FIG. 1 by a distance corresponding to one digit. As the hammer/carry cam holder 19 moves, the hammer 16, carriage 7, type ring group 10, slider frame 11,
The type wheel selection cam 12 and the like are also moved in the D direction by an amount corresponding to one digit, in preparation for the next printing.

As mentioned above, the control lever lock body 61 also rotates half a turn during printing and carrying operations, but as shown in FIGS.
As shown in FIG. 2, the sliding surface 7 of the first lever piece 66a
4a comes into contact with the circumferential cam surface of the stopped print side release cam 42, and the sliding contact surface 74 of the second lever piece 66b
b is in contact with the circumferential cam surface of the stopped type wheel shift side release cam 50, so even if the lock portion 64 of the control lever lock body 61 comes off the fitting surface 72 of the first lever piece 66a, the printer will not be able to move. Tsuji pattern・
The paper feed control lever 65 is held at that position without rotating.

As described above, when the print/carry control board 60, control lever lock 61, print/carry shaft 4, etc. rotate half a turn, one end of the switching member 31 applies the force of the spring to the notch 62 of the print/carry control board 60. At the same time, the other end of the switching member 31 separates from the character position selection ratchet 39 and returns to its original state. And type selection clutch 2
Only 8 is in ON state. In this way, by sequentially repeating the shift selection, rotation stop position selection, printing, and carry of the type wheel 9, one digit is printed.

Next, the carriage return and paper feeding operations will be explained. When carrying out a carriage return/paper feed operation, the release groove 45 of the type side release cam 42 is moved to the first lever piece 6 by an operation command from the control section.
6a and the release groove 50a of the type wheel shift side release cam 50 are connected to the second lever piece 66b.
Shift selection and rotation stop position selection of the type wheel 9 are performed so as to face the sliding surfaces 74b of the type wheels 9, respectively. In this way, the release groove 45 faces the sliding contact surface 74a, and the release groove 50a faces the sliding contact surface 74b, so that the control lever 65
Then, the engagement with the printing side release cam 42 and the type wheel shift side release cam 50 is released. However, at this point, the control lever lock body 61 is stopped with its lock portion 64 fitted into the fitting surface 72 of the first lever piece 66a, so the carriage return/paper feed control lever 65 is locked in the control lever lock. It is locked by the body 61 to prevent rotation.

When the control lever lock body 61 rotates due to subsequent printing/carrying operations, the lock portion 64 locks onto the fitting surface 7 of the first lever piece 66a, as shown in FIG.
2, and the stepped outer peripheral part of the control lever lock body 61 faces the first lever piece 66a.
The carriage return/paper feed control lever 65, which has lost its mooring means, is rotated in the direction of arrow F by the pressure of the biasing spring. At this time, as shown in FIGS. 12 and 13, the tubular portion 76 of the second lever piece 66b
Since the engagement protrusion 78 of the lock release transmitting body 77 is in contact with the lever, the lock release transmitting body 77 is pushed together with the carriage return/paper feed control lever 65 and rotates together. Then, the stopper 83 of the lock release transmitting body 77 is moved to an appropriate stopper piece 97.
13), the carriage return/paper feed control lever 65 and the lock release transmitting body 77 stop rotating.

With this rotation of the lock release transmission body 77,
The idler gear 84, the rack release gear 85, and the rack 5 shown in FIG. 2 rotate, thereby releasing the engagement between the rack teeth 22 and the protrusion 21 of the carry cam 20. When the engagement between the rack 5 and the carry cam 20 is released, the tension of the carriage return spring 8 causes the carriage 7, type wheel group 10, slider frame 11, type wheel selection cam 12, hammer 16, hammer The carry cam holder 19, carry cam 20, etc. return to their home positions. Even when they return to their home positions, the rack 5 remains in a rotating state. Further, when the hammer/carry cam holder 19 is returned to its original state, the rack return member 93 slides as described above, causing its push tooth 94 to face the receiving tooth 95 of the rack 5.

As shown in FIG. 10, when the carriage return/paper feed control lever 65 rotates in the direction of arrow F around the paper feed shaft 6, the paper feed shaft driving ratchet 67 is supported by the paper feed shaft 6. Because it is there, it does not rotate and remains in the same state. As the carriage return/paper feed control lever 65 rotates, the tip of the claw piece 68 supported by it moves.
It crosses over the ratchet tooth one rear of the ratchet tooth of the ratchet 67 that has been engaged so far and engages with it.

Then, based on the subsequent printing/carrying operations, the 11th
When the control lever lock body 61 rotates as shown in the figure, the raised teeth 63 of the control lever lock body 61 lock the control lever 65.
It fits into a groove 98 provided next to the fitting surface 72 of. When the control lever lock body 61 continues to rotate, the control lever 65 is rotated in the direction of arrow G by the raised tooth portion 63 and returns to its original state, and the lock portion 64 of the control lever lock body 61 engages with the control lever 65. Upon contact with the mating surface 72, the control lever 65 is locked again.

As described above, when the control lever 65 rotates in the direction of arrow G, the paper feed shaft driving ratchet 67 is rotated by the claw piece 68 supported thereon. A paper feed shaft 6 is press-fitted and fixed into this ratchet 67, and a paper feed roller 99 made of a rubber roller is connected to the paper feed shaft 6 as shown in FIG. Therefore, the paper feed roller 99 is rotated by the rotation of the paper feed shaft driving ratchet 67, and the paper 17 is fed by a predetermined amount.

Carriage return and paper feeding operations are performed in this manner, but the rack 5 remains disengaged from the carry cam 20. Further, as shown in FIGS. 12 and 13, the notch 75 of the tubular portion 76 of the second lever piece 66b is formed with an enlarged angle, and the engaging protrusion of the narrow release transmission body 77 is formed in the notch 75 of the tubular portion 76 of the second lever piece 66b. 78 is loosely fitted, even if the carriage return/paper feed control lever 65 is rotated in the direction of arrow G to return to its original position, the lock release transmission body 77 will not return and will remain as it is. It's on.

These racks 5 and the rack release transmitter 77
The return of is performed at the first printing on the next line. That is, as described above, the rack 5 is returned to the position facing the carry cam 20 by rotation of the rack return member 93 at the beginning of the printing/carry operation. Also, by rotating the rack 5, the rack release gear 8
5. The lock release transmission body 77 is returned to its original state via the idler gear 84, and becomes capable of engaging with the tubular portion 76 of the second lever piece 66b.

At the time of carriage return, the rack 5 is rotated to disengage from the carry cam 20, thereby carrying out the carriage return, and the rack 5 remains rotated even after the carriage return is completed. The rack 5 is then returned to its original position and engaged with the carry cam 20 at the first print/carry operation of the next line.

In order to further improve the alignment of the print lines printed on the paper 17, each shaft 2, 3 of the carriage 7, type ring group 10, carry cam 20, etc.
The design has been designed to eliminate as much looseness as possible. Therefore, for example, when the printing device is used at low temperatures, the carriage 7, type ring group 10, carry cam 20, etc. do not return easily, and the carriage return operation takes time. Therefore, if the rack 5 is returned to its original position before the carriage return is completed, the carry cam 20 will get caught in the middle of the rack 5, and the printing position on the paper 17 will be different. Therefore, as mentioned above, if you allow some time for the carriage return to start and for the rack to return to its original position, the carriage and carry cam will be able to return to their home positions completely.
The rack can be rotated and engaged with the carry cam, eliminating the above-mentioned inconvenience, and printing can be performed accurately at the correct position even at low temperatures.

As described in detail above, according to the present invention, since the structure includes an intermittent transmission means that shifts the type carrier by one pitch in the direction of the generatrix for each rotation of the type carrier, a single motor is used to move the type carrier toward the generatrix. In addition to being able to select the direction shift and rotational position, it does not require a clutch for shift selection or electromagnetic means to control it, reducing the number of driving sources and simplifying and downsizing the mechanism. It is suitable for use in output devices such as multi-functional desktop electronic computers.

[Brief explanation of the drawing]

The drawings all show a printing device according to an embodiment of the present invention; FIG. 1 is a schematic configuration diagram of the printing device, FIG. 2 is an exploded perspective view of each clutch means and its vicinity,
Figure 3 is a developed view of the cam surface of the type wheel selection cam.
Figures 5 and 6 are a plan view, front view, and developed view of the carry cam; Figures 7 and 8 are a plan view and side view of the rack; Figures 9, 10, and 1
Figure 1 is an explanatory diagram showing the operating states of the control lever lock body, first lever piece, and type side release cam, and Figures 12 and 13 are explanatory diagrams showing the operating status of the second lever piece and type wheel shift side release cam. , FIG. 14 is a perspective view of the rack release transmission body, FIG. 15 is an explanatory view showing the operating state of the rack return member, and FIG. 16 is an explanatory view showing the relationship between the partially toothed gear and the intermittent gear. 5... Rack, 7... Carriage, 10... Type wheel group (type carrier), 11... Slider frame, 12
...Type wheel selection cam, 15...Protrusion, 16...Hammer, 17...Paper, 20...Carry cam, 24
... Rope, 27 ... Motor, 28 ... Print selection clutch, 30 ... Print/carry clutch, 31
... switching member, 33 ... electromagnet, 35 ... timing cam body, 52 ... intermittent gear, 53 ... intermittent gear, 55 ... intermittent rotating gear body.

Claims (1)

[Claims] 1. In a configuration in which the rotational position of a drum-shaped type carrier on which type is formed over a plurality of rows and the shift position of the type carrier in the generatrix direction are selected, and printing is performed by pressing paper against the selected type with a hammer. , a slider frame for holding the type carrier, a type wheel selection cam having a cam groove consisting of a feed cam groove and a return cam groove, and a protrusion engaged with the cam groove;
a transmission means for transmitting the rotation of the motor to the type carrier to rotate the type carrier; and an intermittent transmission means driven by the transmission means for each rotation of the type carrier; For each rotation of the carrier, the intermittent transmission means rotates the type wheel selection cam to shift it by one pitch in the generatrix direction of the type carrier, and the shift of the type wheel selection cam shifts the slider frame. A printing device characterized in that the type carrier held by the sliding frame is shifted by one pitch in the generatrix direction.