JPS6218465Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a serial printer, and more particularly, a type wheel shaft, a type wheel holding member connected to the spline shaft, a type portion held by the type wheel holding member on the outer periphery, and a chain in the axial direction of the type wheel shaft. This relates to a matrix printing type serial printer that is equipped with a type wheel that can be extruded in intersecting directions, and a hammer means for extruding the type wheel and pressing the type portion against paper to print.
To provide a serial printer in which printed characters are well aligned and can print clearly.

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 are diagrams showing the overall schematic configuration of a printer according to an embodiment.

1A and 1B are side frames that constitute a part of the printer frame, and a large number of rotating shafts and guide shafts are spanned in parallel between the both side frames 1A and 1B, and the above-mentioned each are placed on the outer side of one side frame 1A. Controls the rotation of the rotation axis. Gear trains, levers, clutches, electromagnets, etc. are arranged compactly.

In order to reduce power consumption and drive sources, each of the rotating shafts is selectively rotated by a single DC motor 2, which will be explained in detail later. As such, rotation of the type wheels (type carrier unit), vertical shifting of the type wheels, hammering, carriage transfer, and paper feeding are performed. The above-mentioned DC motor 2 has the above-mentioned both side frames 1A and 1B.
It is attached to the side frame 1A below the paper guide plates 3A and 3B attached between them, and is driven by a dry cell battery 4 which is also detachably attached to the lower side of the paper guide plate 3B.

Between the both side frames 1A and 1B, the both side frames 1A,
A carriage 7 guided and held by guide shafts 5 and 6 fixed between 1B is installed, and a coil spring is fixed at one end to the side frame 1B and at the other end to the side plate 8 of the carriage 7. 10, the carriage 7 is constantly pulled in the direction of arrow A in FIG. 1, ie, in the direction of the home position.

As shown in FIG. 3, the carriage 7 includes both side plates 8 and 9, a bottom plate 11 connecting the side plates 8 and 9, and an intermediate plate 12. On the intermediate plate 12, a type wheel group 14 in which type wheels 13 are stacked in four stages is arranged so as to be rotatable and vertically movable.
The type ring group 14 is shifted up and down together with the holder 16 holding the ink roller 15 and the ink roller 15. The type wheels 13 are connected to each other by an Oldham joint, which will be described in detail later, and are movable independently toward the paper (platen 17).
Each type wheel 13 rotates integrally with the type wheel axle 18 via a poppin (described later) that is connected to the type wheel axle 18 by a spline shaft (a connection that rotates integrally with the shaft and is movable in the axial direction). The type wheel shaft 18 is pivotally supported by the intermediate plate 12 of the carriage, and the bevel gear 19 fixed to the type wheel shaft 18 is connected to the type selection shaft 20.
The rotation of the type selection shaft 20 selectively driven by the motor 2 is transmitted to the type wheel group 14.
The type selection shaft 20 is rotatably held between the side frames 1A and 1B by inserting the carriage 7, and gears, cams, clutches, etc., which will be described in detail later, are attached to the part protruding from the side frames 1A. , the bevel gear 2
1 is transported together with the carriage 7.

A support shaft 2 is provided between both side plates 8 and 9 of the carriage 7.
2 is attached, and one ends of two shift levers 23, 23 are pivotally supported on the support shaft 22, and the rotation of the shift lever 23 shifts the type wheel group 14 up and down. There is.

That is, the other end of the shift lever 23 is engaged with the protrusion 24 of the holder 16 of the type ring group 14, and the protrusion at the intermediate portion of the shift lever 23 is engaged with the helical cam groove 25a of the shift cam 25. and
A shift lever 23 is rotated by a shift cam 25 to which the rotation of the motor 2 is selectively transmitted, thereby shifting the type wheel group 14 up and down. The shift cam 25 is spline-coupled to the type wheel shift rotating shaft 26 and is transported together with the carriage 7. The type wheel shift rotating shaft 26 is rotatably held between the side frames 1A and 1B by passing through the carriage 7, and a gear and a cam, which will be described later, are attached to a portion protruding from the side frames 1A.

The carriage 7 further includes a carriage transfer unit.
A rotary shaft 27 for driving the hammer is inserted therethrough, and this carriage is rotatably held between the side frames 1A and 1B. - The carriage is transported integrally with the carriage 7 to the rotary shaft 27 for driving the hammer. A cam 28 for driving the transfer hammer is connected to a spline shaft. The details will be explained later, but
The above-mentioned carriage transfer - the hammer 31 which is pivotally supported on the carriage 7 by the rotation of the hammer driving cam 28;
is driven, one of the aforementioned type wheels 13 is pushed out toward the platen 17 to perform printing, and the cartridge 7 is then transferred by a predetermined amount by the subsequent rotation of the cartridge transfer hammer drive cam 28. ing. That is, below the carriage 7,
A rack body 32 is located along the transport path of the carriage 7, and the specially shaped screw teeth of the cam 28 for driving the carriage transport hammer are engaged with the rack teeth 33 of the rack body 32. Each time the hammer driving cam 28 rotates by a predetermined amount, it moves along the rack body 32 and moves the carriage 7.
will be transferred.

One end of the carriage transfer-hammer drive rotating shaft 27 protrudes from the side frame 1A, and a gear attached to this protruding portion is connected to the rotating shaft of the motor 2 via a gear train and a clutch (details will be described later).

penetrating through the rack body 32 and extending through the rack body 32.
Depending on the amount of rotation, the rotating shaft that rotates integrally with the carriage returns the carriage 7 to the home position (carriage carriage return) or returns the carriage 7 to the home position.
This is hereinafter referred to as the carriage return-back spacing axis 34. This shaft 34 is pivotally supported between the side frames 1A and 1B, and has a gear or the like attached to a portion protruding from the side frame 1A, and rotates only when a cam and lever group described later are in a certain operating state. That is,
Carriage return-back spacing axis 34
When the is rotated greatly, the rack teeth 3 of the rack body 32
3 and the carriage transfer-hammer drive cam 28
The carriage 7, which has lost its mooring means due to the large separation between the screw teeth and the coil spring 1,
It returns to the home position with a tensile force of 0. Also, when the carriage return-back spacing shaft 34 rotates slightly, the rack body 32
The engagement between the screw teeth of the carriage return hammer driving cam 28 is disengaged, and the serrated carriage return prevention projection 35 (hereinafter referred to as serration) on the upper part of the rack body 32 and the screw tooth of the carriage return hammer driving cam 28 are disengaged. The carriage 7 is backspaced by a predetermined amount until the claws 36 are engaged.

In FIG. 1, the two paper guide plates 3 mentioned above are
At the back of the paper path formed by A and 3B, there is a paper feed roller 38 attached to a paper feed shaft 37.
, and the driven roller 3 is pressed toward the paper feed roller.
9 is located, and the paper is transported between both rollers 38 and 39.
The paper is conveyed by the rotation of the paper feed roller 38, and is conveyed to the platen 1 through an appropriate paper guide means.
7 and the type ring group 14. Paper feed shaft 3
Reference numeral 7 is rotatably held by the side frames 1A and 1B, and a gear attached to a portion protruding from the side frame 1A is connected to the rotating shaft of the motor 2 via a gear train and a clutch. It is driven by the motor 2 only when the lever group is in a certain operating state.

Here, the rotation axis of the motor 2 described above is the side frame 1.
The side frame 1A is connected to the side frame 1A via the gear train inside A (not shown).
The drive gear 40 includes the aforementioned type selection shaft 20, the type wheel shift rotation shaft 26, the carriage transfer/hammer drive rotation shaft 27, and the paper feed shaft 37, which are connected to a gear train and a clutch. The shafts 20, 2 are connected via the
6, 27, and 37 are selectively transmitted with the rotation of the motor 2 to perform predetermined operations, and the carriage return-back spacing shaft 34 is connected to the cam group,
Operated by a group of levers. These gear groups, lever groups, cam groups, clutch groups, electromagnet groups, etc. are shown on the right front (outside the side frame 1A) in FIG. 1, but in FIG. 1, each member is laminated and Since it is hidden, this configuration will be explained in detail based on the exploded view of FIG. 2 or each operation explanatory diagram, and only the positional relationship should be noted here.

Next, an outline of the operation will be explained. The rotation of the motor 2 is connected to the type selection shaft 2 via a gear train and a clutch.
0 is transmitted to the type wheel shift rotation shaft 26, which shifts the type wheel group 14 up and down and rotates it to stop the type wheel group 14 at a position where the desired type faces the platen 17 (printing position). This stopping operation is performed by controlling the clutches between the motor 2 and the type selection shaft 20, as well as between the motor 2 and the type wheel shift rotation shaft 26, respectively, by levers driven by electromagnets.
This is done by placing each clutch in a state in which rotation cannot be transmitted (hereinafter referred to as an OFF state).

When both the type selection shaft 20 and the type wheel shift rotation shaft 26 stop rotating, the clutch that controls the rotational transmission between the motor 2 and the carriage transfer/hammer drive rotation shaft 27 is activated by a group of cams and levers. The rotation is in a state in which rotation can be transmitted (hereinafter referred to as an on state), and the carriage transfer/hammer drive rotary shaft 27 rotates once by the motor drive. At the same time, the carriage transfer/hammer driving cam 28 also rotates.
The first half of the rotation of the cam 28 drives the hammer 31 to press the type wheel 13 at a predetermined position against the platen 17 to perform printing. The carriage 7 is transferred by cooperation with the rack teeth 33.

Carriage transfer - hammer drive rotary shaft 27 is 1
When the motor rotates, the clutches between the motor 2 and the type selection shaft 20 and the type wheel shift rotation shaft 26 are turned on, and the clutch between the motor 2 and the carriage transfer/hammer drive rotation shaft 27 is turned off. , the type can be selected at the next transfer position of the carriage 7, and after selecting and stopping the upper and lower shift positions and rotational positions of the type wheel group 14, the hammer operation and the transfer (stepping) of the carriage 7 are performed in the same way as described above. It is done.

When one line of printing is completed, or when the carriage 7 is returned to the home position (carriage return) during the printing process, the type wheel group 14
The shift position is set to a specific position, that is, a position where the type wheel group 14 is at the lowest stage, the type wheel 13 is driven by the hammer 31, and the print data on the paper is visible (hereinafter, this will be referred to as a visible position). 2) selects and stops the type wheel shift rotation shaft 26. At the same time, a first specific rotational position (hereinafter referred to as the carriage return position) of the type wheel group 14, ie, the print selection shaft 20, is selected and stopped.

When the type selection shaft 20 and the type wheel shift rotation shaft 26 stop rotating, a cam (described in detail later) that rotates integrally with the two also stops at a specific position. On the other hand, the motor 2 is activated by the clutch which is turned on when the type selection shaft 20 and the type wheel shift rotation shaft 26 are selected or stopped.
The rotation of rotates another cam, which will be described later, and the lever is activated by the cooperation of this cam and the cams on the type selection shaft 20 and the type wheel shift rotation shaft 26.
The carriage return back spacing shaft 3
Turn 4 by a large amount. Therefore, the mooring between the rack body 32 and the carriage transfer/hammer driving cam 28 of the carriage 7 is released, and the carriage 7 is returned to the home position by the coil spring 10.

The back spacing of the carriage 7 is performed in substantially the same manner as the carriage return operation described above.
That is, selection of the type wheel group 14 to the visible position and selection of the type wheel group 14 (type selection shaft 20) to a second specific rotational position (hereinafter referred to as back spacing position). As a result, each cam on the type selection shaft 20 and the type wheel shift rotation shaft 26 is stopped at a specific position. On the other hand, a cam rotates by a clutch that is turned on when the type selection shaft 20 and type wheel shift rotation shaft 26 are selected and stopped, and a cam on the type selection shaft 20 and type wheel shift rotation shaft 26. The lever, operated in cooperation with the above, now causes the carriage return bag spacing shaft 34 to rotate slightly, as before.

Carriage return back spacing shaft 34
When the is rotated slightly, the rack teeth 3 of the rack body 32
3 and Carriage Transfer - Although the engagement between the screw teeth of the hammer drive cam 28 is disengaged and the carriage 7 begins to return to the home position side by the coil spring 10, the carriage 7 does not engage with the serrated protrusion 35 of the rack body 32. 7 engages, and the carriage 7
At the position where the carriage has returned by 1/2 pitch, the carriage 7
to stop. Then, this 1/2 pitch back spacing is repeated to return the carriage 7 to the desired position.

In addition, immediately after the carriage 7, that is, the carriage transfer hammer driving cam 28 performs back spacing of n+1/2 pitches, the carriage 7 is transferred in the forward direction so that the feed amount is 1/2 pitches. It is configured.

The paper feeding operation also involves selection of the type wheel shift rotation shaft 26 to a visible position and selection of the type wheel shaft 14 (type selection shaft 20) to a third specific rotational position (hereinafter referred to as the paper feeding position). Let's do it. As a result, the cams on the type selection shaft 20 and the type wheel shift rotation shaft 26 are stopped at specific positions, and on the other hand, by selecting and stopping the type selection shaft 20 and the type wheel shift rotation shaft 26, the cams are turned on. Another cam is rotated by a clutch, and this cam and type selection shaft 2 are rotated.
0. In cooperation with the cam on the type wheel shift rotation shaft 26, the clutch between the motor 2 and the paper feed shaft 37 is turned on, and the driving force of the motor 2 is transmitted to the paper feed shaft 37. The paper is conveyed by a predetermined amount. When paper is to be continuously fed, the above operation is repeated to feed the required amount of paper.

Next, the relationship between the motor 2 and each rotating shaft will be explained.

FIG. 2 is a partially simplified exploded perspective view of the gear group, cam group, lever group, clutch group, electromagnet group, etc. arranged on the outer side of the side frame 1A in FIG. The positional relationship is different from the actual arrangement (see Figure 1) for illustration purposes, and the shaft length and some lever lengths are also exaggerated, but the basic structure and operation are completely different from the actual arrangement. are the same.

FIG. 2 shows selective rotational transmission between the motor 2 and type selection shaft 20, type wheel shift rotation shaft 26, carriage transfer/hammer drive rotation shaft 27, paper feed shaft 37, and carriage return/back spacing. The selective rotational movement of the shaft 34 is mainly shown, and the structure of FIG. 2 will be explained below before explaining each detailed structure and its operation.

In FIG. 2, reference numeral 40 denotes a drive gear, which is always rotated counterclockwise by the DC motor 2 when the motor 2 is turned on. 41 is the drive shaft, and the side frame 1
A is rotatably held and rotates together with the drive gear 40. 42 is a camshaft for paper feed control;
A gear 43 is rotatably held at A and is fixed to a paper feed control camshaft 42. The gear 43 is coupled to the drive gear 40 via an idler gear 44, and the motor 2 constantly rotates the gear counterclockwise in FIG. rotate in the direction. Reference numeral 45 denotes a paper feeding intermediate rotary body, which is mounted on the paper feeding control camshaft 42 so as to be rotatable independently from the camshaft 42, and this paper feeding intermediate rotating body 45 and the paper feeding control camshaft 42 are In between is a first clutch 46 (claw clutch) that controls rotational transmission between the two.
is installed.

The paper feed intermediate rotating body 45 includes a cam 47 and a gear 48 for paper feed control, and this gear 48 causes the gear 48 of the paper feed shaft 37 to which the paper feed roller 38 is attached to control the paper feed roller 38. It meshes with the gear 49 of the attached paper feed shaft 37. Two cam ridges 47a are formed at 180 degree intervals on the outer periphery of the paper feed control cam 47, and when a paper feed control lever 50, which will be described later, is in contact with the cam ridges 47a, the first clutch 46 is in the off state. cam mountain 47
When the paper feed control lever 50 is disengaged from a, the first clutch 46 is turned on and the motor 2 is turned on.
The rotation of the drive gear 40, idle gear 44, gear 4
3. The signal is transmitted to the gear 49 of the paper feed shaft 37 via the paper feed control camshaft 42 and the paper feed intermediate rotating body 45, and performs the paper feed operation.

Type selection shaft 20 for rotating type wheel group 14
A gear body 51 is mounted on the protrusion on the side frame 1A side so as to be rotatable independently of the type selection shaft 20. The gear 52 of the gear body 51 is gear-coupled with the drive gear 40 via an idle gear 53,
Driven by the motor 2, it always rotates counterclockwise in FIG. Reference numeral 54 denotes a ratchet fixed to the type selection shaft 20, and a second clutch 55 (spring clutch) is installed between the ratchet 54 and the gear body 51 to control rotational transmission therebetween. The number of teeth of the ratchet 54 corresponds to the symbols formed at equal intervals on the outer periphery of the type ring 13, and a type selection lever 56, which will be described later, can be fitted into the teeth. Then, the teeth of the ratchet 54 and the type selection lever 5
6 is in the disengaged state, the second clutch 55 is in the on state, and the rotation of the motor 2 is transmitted to the ratchet 54 (i.e., the type selection shaft 20) via the idler gear 53 and the gear body 51, and the Type ring group 14
Rotate. Also, when the type selection lever 56 fits into the teeth of the ratchet 54, the ratchet 54
is prevented from rotating, and the second clutch 55
immediately turns off, and the rotational transmission between the gear body 51 and the type selection shaft 20 (ratchet 54) is cut off.

57, 58, and 59 are first, second, and third type selection shaft cams fixed to the type selection shaft 20, and the first type selection shaft cam 57 is related to driving the hammer 31 and feeding the carriage 7; Second type selection shaft cam 58
is associated with paper feed, and the third type selection axis cam 59 is associated with carriage return and carriage back spacing. The first type selection shaft cam 75 includes a large circular portion 57a and a small circular portion 57b, and a cam groove 57c is formed in the large circular portion. The second type selection shaft cam 58 also has a cam groove 58a, and the third type selection shaft cam 59 also has first and second cam grooves 59.
a and 59b are formed respectively. The first cam groove 59a of the third type selection shaft cam 59 is connected to the second cam groove 59a.
The first cam groove 59a is formed deeper than the second cam groove 59b.
The cam groove 59b is related to back spacing. Then, each cam groove 57b, 58a, 5 of the first, second, third type selection shaft cam 57, 58, 59
The cam grooves 9a and 59b are formed out of phase with each other, and the cam grooves 57c, 58a, 59a, 59b
do not overlap when viewed from the axial direction. In addition,
60 is a ratchet 54 (i.e. type selection axis 20)
It is a detection plate that rotates integrally with the type wheel 13, has a slit corresponding to the rotation stop position of the type wheel 13, and cooperates with a detector 61 having a light emitting element and a light receiving element.
3. Each rotation position and rotation reference position are detected.

A control camshaft 62 is rotatably held in the side frame 1A, and a gear 63 is mounted on this shaft 62 so as to be rotatable independently of the control camshaft 62. The gear 63 is connected to the gear 52 of the gear body on the type selection shaft 20 through an idle gear 64, and the rotation of the motor 2 is transmitted through the gear train 40, 53, 52, 64, and is always shown in FIG. It is rotating counterclockwise.

Reference numeral 65 denotes a rotary body for selecting a type wheel shift position, which is rotatably mounted on the control camshaft 62 and is connected to the gear 63 via a third clutch 66 (spring clutch). The rotational transmission of the gear 63 and the rotary body 65 for selecting a type wheel shift position is controlled by the third clutch 66. The rotating body 65 for selecting a type wheel shift position is equipped with a gear 67 and a cam 68 for selecting a type wheel shift position.
8a is formed, and the type wheel group 14 has five shift positions selected by a type wheel shift position selection cam 68. A type wheel shift position selection lever 69, which will be described later, can be freely engaged with the cam groove 68a of the cam 68, and when this lever 69 is disengaged from the cam groove 68a, the third clutch 66 is in the on state. Therefore, the gear 63 driven by the motor 2 and the type wheel shift position selection rotating body 65 rotate together. Further, when the type wheel shift position selection lever 69 is fitted into the cam groove 68a, the type wheel shift position selection cam 68 is prevented from rotating, and the third clutch 66 is immediately turned off and the gear 63 and type wheel shift are stopped. Rotation transmission with the position selection rotating body 65 is cut off. Reference numeral 70 denotes a first cam fixed to the control camshaft 62, and a fourth cam between this and the gear 63 controls rotation transmission between the two.
A clutch 71 (spring clutch) is installed (this fourth clutch 71 is simplified in the illustration, but the hollow shaft portion of the first cam 70 or the hollow shaft portion of the gear 63 is used to select the type wheel shift position). (It is easily installed by inserting the inside of the rotating body 65.) The first cam 70 is provided with two cam grooves 70a, 70a at an interval of 180 degrees, and a part of the type selection lever 56 and a part of the type wheel shift position selection lever 69 are provided in the cam grooves 70a, 70a. are engageable with each other, and both cam grooves 70a,
The fourth clutch 71 is turned on only when the two levers 56 and 69 are disengaged from the lever 70a, and the rotation of the gear 63, which is constantly rotated by the motor 2, is controlled by the first cam 70 (i.e., the control cam shaft 62). transmitted to.

When the type selection lever 56 or the type wheel shift position selection lever 69 is fitted into either of the cam grooves 70a, 70a, the fourth clutch 71 is in the OFF state, and the rotation of the gear 63 is controlled by the control camshaft. 62 (first cam 70).

The control cam shaft 62 has second, third, and fourth cams 72, 73, 74 extending from the first cam 70 toward the tip.
are each fixed. The second cam 72 is involved in the hammer 31 operation and the carriage 7 feeding operation together with the first cam 70, the third cam 73 is involved in paper feeding, and the fourth cam 74 is involved in the carriage return and carriage 7 feeding operation. related to spacing. The second cam 72 is provided with two cam grooves 72a at intervals of 180 degrees, and the cam grooves 72a, 72a are slightly out of phase with the cam grooves 70a, 70a of the first cam 70. Further, the third cam 73 and the fourth cam 74 are respectively provided with two cam ridges 73a, 73a and 74a, 74a at 180 degree intervals, and the cam ridges 73a, 74a of the cams of both cams 73, 74, 74a are shifted in position from each other.

Carriage return back spacing shaft 34
A gear 75 and an intermediate rotary body 76 for carriage transfer/hammer operation control are respectively rotatably mounted on the top, independently of the carriage return bag spacing shaft 34. The gear 75 is connected to the gear body 51 on the type selection shaft 20 via an idle gear 77.
The gear body 51 is connected to the gear 52 of the motor 2, and the gear body 51, which is constantly rotated by the drive of the motor 2, rotates counterclockwise in FIG.

78 is a fifth clutch (spring clutch) installed between the gear 75 and the intermediate rotating body 76.
controls the rotation transmission between the two. Intermediate rotating body 7
6 includes a control cam 79 and a gear 80, and the control cam 79 has two cam ridges 79a, 79 at 180 degree intervals.
A is formed. One end of a third lever 82 of a lever shaft 81, which will be described later, can be freely engaged with this cam ridge 79a, and when the third lever 82 is disengaged from the cam ridge 79a, the fifth clutch 78 is turned on. state, and the intermediate rotating body 76 rotates together with the gear 75. Further, when the third lever 82 comes into contact with the cam ridge 79a to prevent the control cam 79 (intermediate rotating body 76) from rotating, the fifth clutch 78 is immediately turned off, and the connection between the gear 75 and the intermediate rotating body 76 is interrupted. Communication between them is cut off.

Carriage return back spacing shaft 34
A stopper lever 83, which will be described later, is rotatably held on the distal end side of the carriage return back spacing shaft 34, and a gear 84 is fixed to the distal end of the carriage return back spacing shaft 34. It meshes with the sector gear 85d at the tip of the lever 85. Therefore, the rotation of the fifth lever 85 causes the carriage return back spacing shaft 34 to rotate, thereby performing the return or back spacing of the carriage 7.

Carriage return back spacing shaft 34
The gear 80 of the upper intermediate rotating body 76 is a gear 86 fixed to the carriage transfer/hammer drive rotating shaft 27.
The rotation of the motor 2 is transmitted to the carriage transport/hammer driving rotary shaft 27 only when the fifth clutch 78 is in the ON state, so that hammer operation and carriage feeding are performed continuously.

Reference numeral 87 denotes a forward/reverse switching gear body for selecting the shift direction of the type ring group 14, which is rotatable on a support shaft (not shown) fixed to the side frame 1A and slidable by a predetermined amount in the axial direction. Retained. The forward/reverse switching gear body 87 has gears 88, 89 and a connecting portion 90 at both ends, and an operating piece 91a of an electromagnet 91 (hereinafter referred to as a forward/reverse switching electromagnet) for forward/reverse switching is attached to the connecting portion 90. It is being The actuating piece 91
a is biased toward the side frame 1A by a spring (not shown), and therefore, when the forward/reverse switching electromagnet 91 is not energized, the forward/reverse switching gear body 87 is also biased toward the side frame 1A.
moving in the direction.

One gear 88 of this forward/reverse switching gear body 87
is gear-coupled with the gear 67 of the rotary body 65 for type wheel shift position selection on the control camshaft 62 via an idle gear 92, and the play is always maintained within the permissible axial movement range of the forward/reverse switching gear body 87. Gear 92 and gear 8
It meshes well with 8. Therefore, the third clutch 66
is turned on and the type wheel shift position selection rotating body 65 rotates under the drive of the motor 2.
At the same time, the forward/reverse switching gear body 87 rotates counterclockwise in FIG. 2.

A gear 93 and an internal gear 94 are fixed to the type wheel shift rotating shaft 26 to which the shift cam 25 is spline-coupled. It has become a good fit. That is, when the forward/reverse switching electromagnet 91 is in a non-excited state, the forward/reverse switching gear body 8
7 is located close to the side frame 1A, the gear 89 meshes with the gear 93, and when the forward/reverse switching gear body 87 rotates, the type wheel shift rotation shaft 26 rotates clockwise in FIG. Also, forward/reverse switching electromagnet 9
1 is excited and the forward/reverse switching gear body 87 moves to the side frame 1A.
When the gear 89 is moved away from the inner gear 94, the gear 89 meshes with the internal gear 94, and when the forward/reverse switching gear body 87 rotates, the type wheel shift rotation shaft 26 rotates counterclockwise in FIG.

95 is a first fixed to the type wheel shift rotation shaft 26;
The type wheel shift rotating shaft cam contacts a second lever 96 of the lever shaft 81, which will be described later, to control it. Reference numeral 97 denotes a second type wheel shift rotation shaft cam, which is also fixed to the type wheel shift rotation shaft 26, with which one end of the stopper lever 83 comes into contact. The second type wheel shift rotation shaft cam 97 is provided with a cam groove 97a, and at the rotation stop position of the type wheel shift rotation shaft 26 corresponding to the visible position of the type wheel group 14, the stopper lever is inserted into the cam groove 97a. One end of 83 is inserted. A detection plate 98 is fixed to the type wheel shift rotation shaft 26, and detects the shift position of the type wheel group 14 by a detector 99 having a light emitting element and a light receiving element.

Type selection lever 56 and paper feed control lever 5
0 are each rotatably held on a support shaft 100 fixed to the side frame 1A. Type selection lever 5
6 has two lever parts 56a, 56b and a connecting part 56c, and an operating piece 101a of an electromagnet 101 for stopping the rotation of the type wheel is attached to the base side. The operating piece 101a is biased by a spring (not shown) to rotate the type selection lever 66 counterclockwise in FIG. 2 when the electromagnet 101 is not energized.
The tip of a is always in contact with the first shaft cam 70 when the electromagnet 101 is not energized. When the lever portion 56a is fitted into the cam groove 70a of the first cam 70, the tip of the other lever portion 56 is in a state of being separated from the ratchet 54 of the type selection shaft 20, and therefore the Since the second clutch 55 is in the on state, the rotation of the motor 2 is transmitted to the type selection shaft 20. On the other hand, when the type wheel rotation stop electromagnet 101 is excited and the type wheel selection lever 56 rotates clockwise in FIG.
0a, the lever portion 56b is fitted into the ratchet 54, and the second clutch 55 is turned off to stop the type selection shaft 20, thereby selecting the rotation stop position of the type wheel 13. When the lever portion 56a separates from the cam groove 70a, the type wheel shift position selection lever 69 moves to the first cam 70.
Even if the first cam 70 is in the other cam groove 70a, the first cam 70 immediately rotates by a small angle (this configuration will be described in detail later), so that the tip of the lever portion 56a is aligned with the first cam 70. ride on the circular outer periphery of
Even if the excitation of the type wheel rotation stopping electromagnet 101 is cut off, the other lever portion 56b remains in the ratchet 54.
The state of engagement is maintained. This state is maintained until the first cam 70 rotates 180 degrees and the lever part 56a is fitted into the cam groove 70a by the spring force, and at the same time the lever part 56a is fitted into the cam groove 70a, the lever part 56b is As soon as the latch 54 is disengaged, the second clutch 55 is turned on.

The paper feed control lever 50, which is pivotally supported by the support shaft 100, has a trifurcated shape, and is pivotally supported at the center thereof.
A clockwise rotating force is applied in FIG. 2 by a spring (not shown). Each lever part 50a, 50b, 50c of the paper feed control lever 50 is a cam 47 on the paper feed control camshaft 42, a third cam 73 on the control camshaft 65, and a type selection shaft 2.
It is associated with the second type selection shaft cam 58 and the stopper lever 83 on the top. When the stopper lever 83 is in a position where it cannot fit into the cam groove 97a of the second cam 97 of the type wheel shift rotation shaft 26, the lever portion 50c comes into contact with the stopper lever 83, and the lever portion 50a engages the paper feed control cam 47. Cam mountain 4
7a, and the lever portion 50b is in contact with the third
is in a position where it comes into contact with the cam ridges 73a of the cam 73 (a position where it cannot engage with the cam grooves 73b between the cam ridges 73a).

The stopper lever 83 is biased by a spring (not shown) with a rotational force in the counterclockwise direction in FIG. The formed stopper piece 83b is attached to the paper feed control lever 50 and the lever part 50.
c and the fifth lever 8 of the lever shaft 81 which will be described later.
It is said that it can freely come into contact with 5. Therefore, when the projection 83a of the stopper lever 83 is in contact with the circular outer periphery of the second cam 97, the rotation of the paper feed control lever 50 is prevented as described above, but the type wheel shift rotation shaft 26 is not visible. When stopped at the position, the protrusion 83a moves into the cam groove 97a of the second cam 97.
the stopper piece 83 of the stopper lever 83.
b leaves the lever portion 50c of the paper feed control lever 50. Therefore, the type selection shaft 20 stops at a position where the cam groove 58a of the second type selection shaft cam 58 faces the lever portion 50c of the paper feed control lever 50, and in this state, the control cam shaft 62 rotates. The paper feed control lever 5 is inserted into the cam groove 73b of the third shaft cam 73.
At the same time that the lever portion 50c of the 0 is depressed by the spring force, the lever portion 50b is depressed into the cam groove 73b of the second cam 73, and the lever portion 50a is detached from the cam ridge 47a of the paper feed control cam 47. . The paper feed control lever 50 is connected to the paper feed control cam 4.
7, the first clutch 46 is turned on and the rotation of the paper feed control camshaft 42 is transmitted to the paper feed shaft 37 via the paper feed intermediate rotating body 45, thereby performing a paper feed operation. On the other hand, the third cam 73
By the time the paper feed control cam 47 rotates 1/2, the lever part 50a of the paper feed control lever 50 is rotated back to the position where it contacts the cam ridge 47a against the spring force and then stopped. When the paper feed control cam 47 rotates 1/2, the lever portion 5 is attached to the cam ridge 47a.
0a comes into contact and turns off the first clutch 46,
The paper feed shaft 37 is stopped. Of course, at this time, the lever portion 50c of the paper feed control lever 50 is separated from the cam groove 58a of the second type selection shaft cam 58.

Reference numeral 81 denotes a lever shaft fixed to the side frame 1A, and the lever shaft 81 has a type wheel shift position selection lever 69 and a first lever 10 extending from the side frame 1A toward the tip.
2, second lever 96, third lever 82, fourth
The lever 103 and the fifth lever 85 are each held rotatably.

The type wheel shift position selection lever 69 includes lever portions 69a, 69b and a connecting portion 69c, and has an electromagnet 1 on the base side for selecting the shift position of the type wheel group 14.
04 operating piece 104a is attached.

When the electromagnet 104 is in a non-excited state, the operating piece 104a is biased by a spring (not shown) so that the type wheel shift position selection lever 69 rotates clockwise in FIG. 2. In this biased state, the tip of the lever portion 69a is depressed into the cam groove 68a of the cam 68 on the control camshaft 62, and the tip of the other lever portion 69b is separated from the cam groove 70a of the first shaft cam 70. are doing. Therefore, as a result of the cam 68 being prevented from rotating,
When the third clutch 66 is in the OFF state, the rotation of the motor 2 is not transmitted to the type wheel shift rotation shaft 26. On the other hand, when the shift position selection electromagnet 104 is excited, the type wheel shift position selection lever 69 also rotates counterclockwise in FIG.
a, the tip of the lever portion 69b falls into the cam groove 70a of the first cam 70 (at this time, the lever portion 69b is slightly separated from the vertical end surface of the cam groove 70a, and therefore the first cam 70 When the type selection lever 56 is disengaged from the cam groove 70a, it can be rotated by a minute amount as described above). cam 68
When the rotation of the motor 2 is released from the rotation inhibited state by the lever portion 69a, the third clutch 66 is turned on, and the rotation of the motor 2 is controlled by the rotation shaft 6 for type wheel shift position selection.
5 to the type wheel shift rotation shaft 26,
The type wheel shift rotation shaft 26 is a forward/reverse switching gear body 87
The printing wheel group 14 is shifted either upward or downward according to the position of the printing wheel.

When the type ring group 14 is shifted to the desired position,
At the same time, the power to the shift position selection electromagnet 104 is cut off, and the spring force rotates the type wheel shift position selection lever 69 clockwise in FIG. At the same time as the first cam 70 is removed from the cam groove 70a, the lever portion 69a falls into the cam groove 68a of the cam 68 to prevent the rotation of the type wheel shift position selection rotating body 65. This causes the third clutch 66 to turn off and immediately stop the type wheel shift rotation shaft 26.
The type wheel group 14 is stopped at a desired shift position.

The first lever 102 and the second lever 96 of the lever shaft 81 are mounted on the lever shaft 81 so as to be movable by a predetermined amount in the axial direction. The lever 102 and the second lever 96 are always pressed in the direction of the third lever 82, and the levers 102, 96, 82 are always in close contact with each other. The second lever 96 and the third
An end cam is provided on the contact surface with the lever 82, and as the second lever 96 rotates, the second lever 96 and the first lever 102 move together in the axial direction. That is, the tip of the second lever 102 to which a counterclockwise rotational force is applied in FIG. 2 by a spring (not shown) is connected to the type wheel shift rotation shaft 26
The top of the first shaft cam 95 is in constant contact with the outer peripheral surface of the upper first shaft cam 95, and only in the stop position corresponding to the visible position of the type wheel shift rotation shaft 26, the top of the first shaft cam 95 is in contact with the second lever. 96 is rotated clockwise in FIG. By rotating the second lever 96 in the clockwise direction, the second lever 96 and the first lever 10 are rotated.
2 slides toward the third lever 82 by the end cam. Furthermore, when the type wheel shift rotation shaft 26 is removed from the stop position corresponding to the visible position, the second lever 96 is rotated counterclockwise in FIG. The second lever 102, 96 slides toward the side frame 1A.

The first lever 102 is given a rotational force in the clockwise direction in FIG. 2 by a spring (not shown), and its rotation is prevented by the bent portion 82c of the third lever 82. . When the first lever 102 is moving toward the side frame 1A, the first lever 102 faces the small circular portion 57b of the first type selection shaft cam 57 at a distance, and the lever 102 faces the third When it is moving toward the lever 82 side, it is in contact with the circular outer periphery of the large circular portion 57a of the first type selection shaft cam 57. Therefore, when the first lever 102 is in a position facing the small circular portion 57b, the third lever 82 is moved at all rotational positions of the type selection shaft 20.
Rotation in the counterclockwise direction in FIG. 2 is allowed.
Further, when the first lever 102 is in contact with the outer periphery of the large circular portion 57a, the cam groove 57 of the large circular portion 57a
The third lever 82 is only allowed to rotate in the counterclockwise direction in FIG. In the pivoted position the third lever 8
2, counterclockwise rotation in FIG. 2 is prevented.

The third lever 82 includes lever portions 82a, 8
2b and a bent portion 82c provided on the lever portion 82a, and is provided with a rotational force in the counterclockwise direction in FIG. 2 by a spring (not shown). When the control camshaft 62 is in a stopped state,
The tip of the lever portion 82a abuts the cam ridge 72b of the second cam 72, and the tip of the other lever portion 82b abuts the cam ridge 79a of the control cam 79 on the carriage return-back spacing shaft 34. Rotation of the control cam 79 is prevented. Therefore, the fifth clutch 78 is in the off state;
The rotation of the motor 2 is not transmitted to the carriage transport/hammer drive rotary shaft 27. Also, at this time, since the third lever 82 cannot rotate in the counterclockwise direction in FIG. 2, the bent portion 82c does not rotate the first lever 102 in the same direction.

On the other hand, the first lever 102 connects its tip to the small circular portion 57b of the first type selection shaft cam 57 or the cam groove 5.
7c, the control camshaft 62
When the third lever 82 starts to rotate, the lever portion 82a of the third lever 82 rotates counterclockwise with the tip of the lever portion 82a falling into the cam groove 72a as the second cam 72 rotates. As a result, the first lever 10
2 is pushed by the third lever 82 and rotates counterclockwise, and the lever part 82b of the third lever 82
is detached from the cam ridge 79a of the control cam 79. Since the spring force of the spring is larger than that of the first lever 102, the first lever 102 is stronger than the third lever 82.
(Easily pressed and rotated by)

Then, when the third lever 82 is disengaged from the control cam 79, the cam 79 is allowed to rotate, so the fifth clutch 78 is turned on, and the rotation of the motor 2 is controlled by the control cam 79 (intermediate rotating body 76). The carriage transfer is transmitted to the hammer driving rotary shaft 27, which drives the hammer 31 and one of the carriages 7.
Perform pitch transfer.

Also, a rotary shaft 27 for carriage transfer and hammer drive.
The control camshaft 62 is rotating even while the control camshaft 62 is rotating, and when the control camshaft 62 starts rotating, the type selection lever 56 fits into the cam groove 70a of the first cam 70. It continues to rotate until then.

Therefore, before the control camshaft 62 completes 1/2 rotation, the second cam 72 that rotates together with the control camshaft 62 moves the tip of the lever portion 82a of the third lever 82 into the cam groove 7.
2a to contact the cam ridge 72b, and
Turn the lever 82 clockwise in FIG. Therefore, the tip of the lever portion 82b of the third lever 82 moves to a position where it comes into contact with the cam ridge 79a of the cam 79 before the control cam 79 completes 1/2 rotation. Then, when the control cam 79 rotates 1/2, the lever part 82b comes into contact with the cam ridge 79a to prevent the control cam 79 from rotating, and the fifth clutch 78 is turned off to move the carriage transfer/hammer drive rotary shaft. 27 is stopped.

The fourth lever 103 of the lever shaft 81 is given a rotational force in the counterclockwise direction in FIG. 2 by a spring (not shown), and when the control camshaft 62 is in a stopped state, the fourth lever 103 It is in contact with the cam ridge 74a of the upper fourth cam 74. This fourth
The lever 103 is provided with a bent portion 103a for pressing a lever portion 85a of a fifth lever 85, which will be described later.

The fifth lever 85 on the lever shaft 81 has a trifurcated shape and is pivotally supported by the lever shaft 81 at its center. The lever portion 85a of the fifth lever 85 contacts the bent portion 103a of the fourth lever 103, and the lever portion 85b contacts the stopper piece 83b of the stopper lever 83 and the third character selection shaft cam 59. Free and unique lever part 85c
The sector gear 85d meshes with the gear 84 of the carriage return-back spacing shaft 34. As described above, when the type wheel shift rotation shaft 26 is in a rotational position other than the visible position, the protrusion 83a of the stopper lever 83 comes into contact with the circular outer periphery of the second type wheel shift rotation shaft cam 97. Therefore, the stopper piece 83b of the stopper lever 83 is connected to the lever part 85b of the fifth lever 85.
The fifth lever 85 is located at a position where it comes into contact with the tip, and the fifth lever 85 is prevented from rotating in the counterclockwise direction in FIG.

On the other hand, the type wheel shift rotation shaft 26 stops at a position corresponding to the visible position, the protrusion 83a of the stopper lever 83 falls into the cam groove 97a of the second type wheel shift rotation shaft cam 97, and the stopper piece of the stopper lever 83 83b is the fifth lever 85
, and the type selection shaft 20 moves away from the first lever portion 85b of the third type selection shaft cam 59.
When the control cam shaft 62 rotates while the cam groove 59a or the second cam groove 59b is stopped at a position where the tip of the lever portion 85b of the fifth lever 85 is opposed, the fourth cam rotates integrally with the control cam shaft 62. 74, the tip of the fourth lever 103 falls from the cam ridge 74a into the cam groove 74b, and the fourth lever 103 rotates counterclockwise in FIG. 2. When the fourth lever 103 rotates, it is pressed and the fifth lever 85 also rotates counterclockwise in FIG. It falls into the first cam groove 59a or the second cam groove 59b of the cam 59. Therefore, the fifth lever 85 rotates by an amount corresponding to the depth of the first cam groove 59a or the second cam groove 59b, and the sector gear 85 of the lever portion 85c rotates.
d rotates gear 86 on carriage return-back spacing shaft 34. When this rotates, the rack body 32 rotates in response to the rotation, and the carriage 7 is returned to its home position or backspaced.

Then, the control camshaft 62 is rotated by a predetermined amount (1/2 rotation)
Before rotating and stopping, the fourth lever 103 is returned to the state where it rests on the cam crest 74a of the fourth cam 74 shown in FIG. By rotation, the fifth lever 85 also moves into the cam groove 59 of the third type selection shaft cam 59.
It returns to the state shown in the second figure in which it is separated from a or 59b, and along with this, the carriage return-back spacing shaft 34 also returns to its original position.

As is clear from the above description, in the serial printer according to this embodiment, the driving force of the DC motor 2, which is constantly rotating at high speed in a fixed direction, is selectively applied to the type selection shaft 20, the type wheel shift rotation shaft 26, ,
It is transmitted to the control camshaft 62, the carriage transfer/hammer drive rotary shaft 27, and the paper feed shaft 37, which are directly driven by the motor 2 via a clutch and gear train, and the carriage return/back spacing shaft 34. is selectively driven by the combined output of a cam and a lever. FIG. 4 is a simplified schematic diagram of this rotation transmission system.

In FIG. 4, a drive gear 40 driven by a motor 2 transfers the driving force of the motor 2 to a type selection shaft 20,
Gears 52, 63, 63, 7 for transmitting information to the control cam shaft 62, type wheel shift rotation shaft 26, carriage transfer/hammer drive rotation shaft 27, and paper feed shaft 37
5 and 43, and these are constantly rotated. The second clutch 55 is disposed between the gear 52 and the type selection shaft 20, the third clutch 66 is disposed between the gear 63 and the control camshaft 62, and the gear 75 is disposed between the gear 52 and the type selection shaft 20.
A fifth clutch 78 is provided between the rotary shaft 27 for driving the carriage transfer/hammer, and a first clutch 46 is provided between the gear 43 and the paper feed shaft 37. Controls the rotational transmission between the

In the figure, 105 represents a cam group of the type selection shaft 20, a cam group of the control cam shaft 62, a cam group of the type wheel shift rotation shaft 26, and a lever group that cooperates with these cams. Reference numeral 106 represents a forward/reverse clutch consisting of the gear 93, the internal gear 94, and a forward/reverse switching gear body 87 for switching the direction of rotation of the type wheel shift rotating shaft 26. The second clutch 55 is controlled by a type selection lever 56 driven by an electromagnet 101 for stopping rotation of the type wheel, and the third clutch 66 is controlled by a type selection lever 69 driven by a shift position selection electromagnet 104. , the fourth clutch 71 is controlled by a type selection lever 56 and a type wheel shift position selection lever 69, and the forward/reverse clutch 106 is controlled by a forward/reverse switching electromagnet 91. Also, the first clutch 46, the fifth clutch 78, and the gear 84 of the carriage return back spacing shaft 34 are controlled by the output of the cam lever group 105.

Now, in the printing standby state, each electromagnet is in a non-excited state, so the type wheel rotation stop electromagnet 10
a second clutch 5 that is turned on when clutch 1 is de-energized;
1st, 3rd, 4th, and 5th clutches 46, 6 except for 5.
6, 71, and 78 are in the off state.

From this state, when the motor 2 starts rotating based on the print command, the type selection shaft 20 rotates and the detector 6
1 detects the rotation reference position of the type selection shaft 20, and also detects a signal corresponding to each type of type on the type wheel 13. ). On the other hand, when the motor 2 reaches a constant speed state, the other detector 99 detects whether the shift position of the type wheel group 14 is in the visible position or another shift position, and detects whether the shift position of the type wheel group 14 is in the visible position or in another shift position. In this case, a sequence is executed in which the type wheel group 14 is moved down one step by a shift operation of the type wheel group 14, which will be described later, until the detector 99 detects a visible position. As a result, it is confirmed that the shift position of the type wheel group 14 is in the visible position, and absolute position detection is no longer performed from then on, and the control circuit is operated by the forward/reverse switching electromagnet 9.
counting the number of ups and downs of the type wheel group based on the supply signal to 1 and the detection signal of the detector 99;
Calculate the current position. Next, carry out the carriage return operation and paper feed operation, which will also be described later.
To confirm the return of the carriage 7 to the home position and to prevent double printing of print data on paper.

From this state, based on the printing command, the printer control circuit determines the necessity and direction of shifting of the type wheel group 14, and the forward/reverse switching electromagnet 9 of the forward/reverse clutch 106.
If 1 excitation is required, until the shift is completed,
Power this from the beginning. This forward/reverse clutch 10
6 is completed, the shift position selection electromagnet 104 is energized to rotate the type wheel shift rotation shaft 26.

Based on the subsequent printing command, the type wheel rotation stop electromagnet 101 is energized, and the shift position selection electromagnet 104 is de-energized.
The third clutches 55, 66 are turned off one after the other, and the type selection shaft 20 and the type wheel shift rotation shaft 2 are turned off.
6 stops. Therefore, the type wheel group 14 is stopped after conveying the desired type to the printing position.

When the second and third clutches 55 and 66 are off, both the type selection lever 56 and the type wheel shift position selection lever 69 are disengaged from the first cam 70 that controls the fourth clutch 71 described above. state, the fourth clutch 71 is turned on, causing the control camshaft 62 to rotate.

On the other hand, since the printing operation is being performed in this case, the type wheel shift rotation shaft 26 is not in the visible position, and therefore the rotational output of the control camshaft 62 is set to the output 0 _{to 1} of the cam lever group 105, which is the fifth output. The signal is transmitted to the clutch 78, and the fifth clutch 78 is turned on to transfer the carriage - the rotary shaft 27 for driving the hammer.
is rotated by motor 2. When the carriage transfer-hammer drive rotary shaft 27 rotates once, the carriage transfer-hammer drive cam 2 is rotated in synchronization with this rotation.
8 also makes one rotation, the hammer 31 is driven in the first half rotation, and the carriage 7 is transferred one pitch along the rack body 32 in the second half rotation. When the carriage transfer/hammer drive rotary shaft 27 rotates once, it returns to the initial state in which only the second clutch 55 is on, as described above.

In order to transfer only the carriage 7 without printing, it is necessary to select the visible position of the type wheel shift rotation shaft 26 and the spacing position of the type selection shaft 20 (the first type selection shaft cam 57).
(selection of type letters corresponding to the cam grooves 57c). In this case as well, the rotation of the control camshaft 62 is controlled by the cam
The output of the lever group 105 is 0 to ₁ , and the fifth clutch 78 is turned on to rotate the carriage transfer/hammer drive rotary shaft 27 once. However, even if the hammer 31 is driven, the type wheel group 14
Since the printer is in the visible position, the carriage 7 is transported one pitch without printing. If further spacing is required, repeat the above operation. Note that at this time, the type ring group 14 is in the visible position, so
The operator can see the print data of the line being printed on the paper.

To feed the paper, press the type wheel shift rotation shaft 2.
6 to the visible position, and selection of the type selection shaft 20 to the paper feed position (selection of the type corresponding to the cam groove 58a of the second type selection shaft cam 58). As a result, the control camshaft 6
The rotation of 2 is transmitted to the first clutch 46 as output ₀₃ of the cam lever group 105, and the first clutch 46 is turned on to rotate the paper feed shaft 37 by a predetermined amount and transfer the paper 1/2 pitch. . When the paper feed shaft 37 rotates enough to transport the paper 1/2 pitch, the printer returns to the initial state where only the second clutch 55 is on, so the above operation is repeated twice in succession to feed the paper 1 pitch. In order to continuously feed the paper, the above series of operations is repeated.

To return the carriage 7 to the home position, select the visible position of the type wheel shift rotation axis 26 and select the carriage return position of the type selection axis 20 (the third type of the type selection axis 20). First cam groove 59a of selection shaft cam 59
). As a result, the rotation of the control camshaft 62 is controlled by the cam lever group 105.
The output ₀₂ is transmitted to the carriage return back spacing shaft 34, causing the rack body 32 integrated therewith to rotate, and the rack teeth 33 of the rack body 32 to rotate.
and carriage transfer - the mooring state between the hammer drive cam 28 and the screw teeth is released, and the carriage 7 is rapidly returned to the home position by the tensile force of the coil spring 10. At this time, the control camshaft 62 rotates a predetermined amount and before stopping, the related lever group is returned to its initial state, and the type selection shaft 20, which starts rotating immediately after the control camshaft 62 stops, also rotates to the fifth position. The lever 85 is returned to its initial state. Therefore,
Before the carriage 7 returns to the home position, the carriage return/back spacing shaft 34 is rotated via the fifth lever 85 to connect the rack body 32 and the carriage transfer/hammer drive cam 28.
There is a risk that the carriage may become engaged and prevent the carriage return. Therefore, the above-mentioned carriage return operation is repeated and the printer does not perform a new printing operation until the detection means for detecting the return of the carriage 7 to the home position is turned on.

When back spacing the carriage 7, the type wheel shift rotation shaft 26 is selected to the visible position and the type selection shaft 20 is set to the back spacing position (the third position of the type selection shaft 20 is selected).
(selection of the type corresponding to the second cam groove 59b of the type selection shaft cam 59). By this,
The rotation of the control camshaft 62 is controlled by the carriage return-back spacing shaft 3 as the output ₀₂ of the cam/lever group 105 in the same way as during carriage return operation.
The signal is transmitted to the gear 84 of No. 4. However, the above-mentioned output ₀₂ now works to slightly rotate the carriage return-back spacing shaft 34, causing its rack body 32 to move toward the aforementioned carriage 7.
Perform back spacing by rotating the amount necessary to back up by 1/2 pitch.

Next, the configuration around the type wheel group and the operation for selecting the rotation position of the type wheel will be explained.

As mentioned above, the type wheel group 14 includes four type wheels 13.
The outer periphery of each type ring 13 is provided with type parts such as alpha alphabet symbols and numerical symbols.

As shown in FIGS. 5, 7, and 8, each type ring 13 has an annular shape and has two parallel partition walls 13a, 13a inside. This partition wall 13a,
An elastic ring 120 made of elastic rubber or the like is located in the center of the oval-shaped cavity formed by 13a, and is positioned by a compensating member 121. Reference numeral 122 denotes a sliding rotation 3, which is engaged between the partition walls 13a, 13a at the top and bottom of each type ring 13 so as to be slidable only along the partition wall 13a. The sliding rotor 122 has an upper sliding rotor portion 12 formed such that the linear portions thereof are perpendicular to each other.
2b and a lower sliding rotor part 122c, the upper sliding rotor part 122b engages with the lower part of the upper type wheel 13, and the lower sliding part rotor 122c engages with the upper part of the lower type wheel 13. ing. That is, each type wheel 1
3 are stacked with their partition walls 13a orthogonal to each other and connected by a sliding rotor 122 between them to form an Oldham joint.

A bobbin 123 is made of a synthetic resin molded product or a processed metal product, and is fitted onto the type wheel shaft 18 and connected to it by a spline shaft. The bobbin 123 is a lower bobbin 123A and an upper bobbin 12.
3B, the upper end of the hollow shaft portion 123A-2 of the lower bobbin 123A and the upper bobbin 123B
and are combined using a so-called snap-in. The hollow shaft portion 123A-2 includes the center hole 1 of each elastic ring 120.
20a and the center hole 122a of the sliding rotor 122
is inserted. lower and upper bobbin 123A,
123B (only the partition wall 123A-1 of the lower bobbin 123A is shown in FIG. 5)
, the sliding rotor 12 at the bottom of the lowermost type wheel 13
The upper sliding rotor 122 of the bobbin 123 and the uppermost type wheel 13 are engaged with each other, and an Oldham joint is also formed between the bobbin 123 and the type wheel 13.

Therefore, the rotation of the type wheel shaft 18 is transmitted to each type wheel 13 via the bobbin 123 and they rotate together, and the elastic ring 120 is elastically deformed, so that the type wheel 13 is perpendicular to the type wheel shaft 18. It can be displaced in the direction. In order to facilitate this displacement, the elastic ring 120 is provided with a plurality of small holes 120b, as shown in FIG.

In order to push out the type wheel 13 perpendicularly to the type wheel axis 18 toward the platen 17, support arms 126, 12 are inserted from both sides of the holder 16 toward the platen 17.
6 is integrally provided. This support arm 126
are provided in four stages corresponding to the number of type wheels 13. On the other hand, a stepped portion 13b having a smaller diameter is integrally formed at the lower part of each type ring 13, and as shown in FIG.
6, 126, and the type ring 13 is inserted between the support arm 1
26 and is pushed out only to the platen 17 side.

Reference numeral 124 denotes a disc-shaped pressing plate housed in the groove window 125 of the holder 16, and the step part 13b of the type wheel 13
, and a part thereof is exposed to the outside through the groove window 125. Therefore, as shown in FIG. 8, when the hammer 31 rotates and presses the press plate 124, the press plate 124 presses the stepped portion 13b of the type ring 13, elastically deforms the elastic ring 120, and presses the press plate 124. 13
is pressed against the platen 17 via the paper 112.
When the hammer 31 returns to its original position, the type ring 13 pushed out toward the platen 17 also returns to its original position due to the elastic force of the elastic ring 120.

In FIGS. 7 and 8, reference numeral 127 denotes a top cover that pivotally supports the ink roller 15, and is attached to the holder 16 by appropriate means. Further, in FIGS. 5 to 8, reference numeral 130 is a positioning body made of metal or synthetic resin, which is curved and has both ends fixed to the outside of the support arms 126, 126 by appropriate means, or is formed integrally with the support arms 126, 126. There is. This positioning body 130 also supports the type ring 1 in the same way as the support arm 126.
(In FIG. 1 and FIG. 3, illustration of the positioning body 130 is omitted.) The tip of each positioning body 130 (platen 1
7 side) has a protrusion 1 whose planar shape is approximately triangular.
30a is integrally provided. On the other hand, type wheel 1
The positioning body 13 is provided on the outer periphery of the step portion 13b of No.
V-shaped grooves 13c into which the 0 protrusions 130a fit are formed, and these are provided in correspondence with the positions of the type portions provided on the outer periphery of the type wheel 13 (see FIG. 5).

Since the positioning body 130 is fixed to the holder 16, it moves up and down along the axial direction of the type wheel shaft 18 together with the type wheel group 14, but remains in a fixed state when the selected type wheel 13 is pushed out. . Then, by extruding the type ring 13, the positioning body 130
The protrusion 130a fits into the groove 13c of the stepped portion 13b of the type wheel 13 facing it, positioning the type wheel 13 in the circumferential direction, and immediately after that, the paper 112
is printed on. At least one of the groove 13c of the stepped portion 13b and the protrusion 130a of the positioning body 130 has a tapered outer shape so that the circumferential positional deviation of the type ring 13 can be corrected to the normal position. If the positional deviation of the type ring 13 in the circumferential direction is large, the protrusion 130a does not fit into the groove 13c and hits the outer peripheral surface of the stepped portion 13b, preventing further extrusion and displacement of the type ring 13, and the paper 112 No printing is done.

As described above, the rotary position selection operation of the type wheel 13 is performed by controlling the rotation of the motor 2 by controlling the rotation position of the type selection lever 56.
Through the clutch 55 controlled by By energizing the stopping electromagnet 101, the second clutch 55 is turned off via the type selection lever 56 to stop the rotation of the type ring group 14. The groove formation and operation have been described in detail previously. The details are omitted here.

Note that this type wheel rotation position selection operation is performed even when the vertical shift operation of the type wheel group 14 is not performed (even when it is unnecessary), and the forward spacing of the carriage 7, the carriage return, the back spacing, and the paper It should be noted that the rotational position of the type wheel 13 is necessarily selected for each of these feeding operations, since this serves as a trigger for each of the feeding operations. Furthermore, as described above, since the configuration is adopted in which a reference position signal is detected every time this rotation selection operation is performed, the type wheel group 14 always rotates at least once before printing is selected, and is rotated by the ink roller 15 described above. It should also be noted that the entire outer periphery of the type wheels 14 is inked with each print selection operation.

Next, the shift position selection operation of the type wheel group will be explained.

The shift (vertical movement) position of the type wheel group 14 is selected, as described above, when the shift direction (rotational direction of the type wheel shift rotation shaft 26) needs to be changed, prior to the rotation of the type wheel shift rotation shaft 26. It is done. That is, as shown in FIG. 9, the forward/reverse switching gear body 87 for transmitting the rotation of the motor 2 to the type wheel shift rotating shaft 26 in forward or reverse rotation is in the ninth position when the forward/reverse switching electromagnet 91 is energized. It meshes with the internal gear 94 of the type wheel shift rotating shaft 26 when it is in the solid line position, and meshes with the gear 93 of the type wheel shifting rotating shaft 26 when it is in the position shown by the two-dot chain line in FIG. 9 when it is not energized.

Now, when the forward/reverse switching gear body 87 is meshing with the internal gear 94, when the shift position selection electromagnet 104 shown in FIG. It is transmitted to the wheel shift rotation shaft 26, and as described above, rotates the type wheel shift rotation shaft 26 in the counterclockwise direction in FIG.

As a result, the shift cams 25, 25, which are spline-coupled to the type wheel shift rotating shaft 26 and are transported together with the carriage 7, also rotate counterclockwise in FIG. 3. Therefore, the spiral cam groove 2 of the shift cams 25, 25
Shift levers 23, 23, which have protrusions (not shown) engaged with 5a, 25a, respectively, rotate clockwise in FIG. 3 about the support shaft 22. Therefore, the holder 16 whose protrusion 24 is engaged with the two prongs at the tip of the shift lever 23 is shifted upward together with the type ring group 14. In FIG. 3, reference numerals 128, 128 are support shafts for guiding the vertical sliding movement of the holder 16, and are fixed to the bottom plate 11 of the carriage 7.

When the forward/reverse switching gear body 87 is engaged with the gear 93, the type wheel shift rotation shaft 26 and the shift cam 25 rotate in the opposite direction to that described above, and the shift lever 23 moves counterclockwise in FIG. It rotates to shift the holder 16 (type ring group 14) downward.

When the type wheel group 14 is shifted to a desired position, the shift position selection electromagnet 104 is de-energized, the third clutch 66 is turned off, the type wheel shift rotation shaft 26 is stopped, and the type wheel group 14 is shifted to a desired position. As described above, the group 14 is stopped and held at a desired shift position. 7 shows a state in which the visible position of the type wheel group 14 is selected, and FIG. 8 shows a state in which the second type type wheel 13 from the top has been shifted to the printing position.

Next, the hammer operation will be explained.

As described above, when the rotation position selection and shift position selection of the type wheel group 14 are completed, the type selection lever 56 and the type wheel shift position selection lever 69 are activated.
is removed from the cam groove 70a of the first cam 70, the fourth clutch 71 is turned on, and the control camshaft 62 is driven by the motor 2. Incidentally, the rotational position selection and the shift position selection are performed at the same time, and whether the type selection lever 56 or the type wheel shift position selection lever 69 leaves the cam groove 70a of the first cam 70 first. Whether it is or not is optional. However, when the rotational position detection is completed first and the first cam 70 is in a stopped state, the type selection lever 56 is returned to its original state by the spring as the electromagnet 101 for stopping rotation of the type wheel is de-energized. Cam groove 7
0a, so even if the shift position selection ends after this and the type wheel shift position selection lever 69 is disengaged from the cam groove 70a, the type selection lever 56 does not prevent the rotation of the first cam 70. This results in a state in which the fourth clutch 71 is not turned on. Therefore, in order to prevent the above situation, measures as shown in FIG. 10 have been taken.

FIG. 10a shows a state in which the type selection shaft 20 and the type wheel shift rotation shaft 26 are rotating together. That is, the type wheel rotation stop electromagnet 101 is de-energized, the type selection lever 56 comes into contact with the vertical surface of the cam groove 70a of the first cam 70, and the shift position selection electromagnet 104 is energized to shift the type wheel. When the position selection lever 69 reaches the position shown by the two-dot chain line to the position shown by the solid line, the tip of the type wheel shift position selection lever 69 is also within the cam groove 70a. The type wheel shift position selection lever 69, which is driven by the excitation of the shift position selection electromagnet 104, is connected to the cam groove 70.
When it enters the inside a, it enters a position approximately 5 to 10 degrees in the rotational direction of the first cam 70 (counterclockwise in the drawing), and is in a non-contact position with the vertical surface of the cam groove 70a. Therefore, the type wheel rotation stop electromagnet 101 is energized for a predetermined period from the state shown in FIG. 10a,
When the type selection lever 56 separates from the cam groove 70a before the type wheel shift position selection lever 69 (when the lever 56 rotates clockwise in the figure),
The first cam 70 is allowed to rotate a small amount in the counterclockwise direction in FIG. 10, and after rotating until the type wheel shift position selection lever 69 comes into contact with the vertical surface of the cam groove 70a, it stops (during this time 4th clutch 7
1 is turned on for a short period of time). This first cam 70
In the position where the character selection lever 56 is slightly rotated,
Even if the type wheel rotation stopping electromagnet 101 attempts to rotate in the counterclockwise direction shown in the figure by the spring force as the electromagnet 101 for stopping the type wheel rotation is de-energized, the type selection lever 56 does not fit into the cam groove 70a and rotates as shown in FIG. 10b. As shown in FIG. Therefore, as described above, the type selection lever 56 resists the spring force and moves the lever part 56a to the circular outer peripheral part of the first cam 70 and the other lever part 56b to the ratchet 5.
The state of engagement with the teeth of No. 4 is maintained. and,
Thereafter, when the type wheel shift position selection lever 69 is released from the cam groove 70a by de-energizing the shift position selection electromagnet 104 (shift position selection stop operation), the first cam 70 is allowed to rotate. (that is, the fourth clutch 71 is turned on), the control camshaft 62 rotates, and the control camshaft 62 rotates approximately halfway until the type selection lever 56 falls into the cam groove 70a by the spring force. Turn around. That is, 180 degrees - (5 degrees to
10 degrees). In addition, when the control camshaft 62 is slightly rotated by 5 degrees to 10 degrees, the cam ridges 72b, 73a, 7 of the second, third, and fourth cams 72, 73, 74
The third lever 82, the paper feed control lever 50, and the fourth lever 103 engaged with the cam groove 72
a, 73b, 74b, and the cam mount 72b,
Of course, the state in which it is in contact with 73a and 74a is maintained.

When the control cam shaft 62 starts to rotate, the second cam 72 also rotates, and with this rotation, the cam groove 72a of the cam 72 reaches a position where it can engage with the third lever 82, and as described above, the first lever 102
The small circular portion 57b of the first type selection shaft cam 57
Alternatively, only when the third lever 82 is in a position corresponding to the cam groove 57c, the second control camshaft cam 7
The fifth clutch 78 is turned on to rotate the carriage transfer-hammer driving rotary shaft 27 one revolution.

FIG. 11 shows the above-mentioned second lever 96 and the third lever 96.
An example of an end cam shown between the lever 82 and the lever 82 is shown. In the figure, the first and second levers 102 and 96, which are in close elastic contact with the third lever 82 by a spring, are connected to the type wheel shift rotation shaft 2.
6 is in the visible position, the second lever 96 is pressed down by the protrusion of the first shaft cam 95, as shown by the solid line. At this time, the pin 82d of the third lever 82 is in contact with the lower plane in the figure of the end cam 96a of the second lever 96, and therefore the first lever 102 is pressed by the spring.
is located at a position facing the large circular portion 57a of the first type selection shaft cam 57. When the type selection shaft 20 is not in the spacing position, the tip of the first lever 102 is in contact with the outer periphery of the large circular portion 57a, and the third lever 82 is in contact with the cam groove 72a of the second cam 72. It is not allowed to engage with the

Further, when the type wheel shift rotation shaft 26 is not in the visible position, the second lever 96 is pushed up by the spring force as shown by the two-dot chain line in FIG. The pin 82d is located on the higher plane in the figure of the end cam 96a of the second lever 96 via the inclined surface of the end cam.
Therefore, the first lever 102 is pushed by the second lever 96 and slides to the right in FIG.
The tip of the first lever 102 faces the small circular portion 57b of the first type selection shaft cam 57 with a predetermined distance therebetween.
When the first lever 102 is located at the position indicated by the two-dot chain line shown in FIG.
The third lever 82 is allowed to move in all rotational positions, and as a result of engaging with the cam groove 72a of the second cam 72, the fourth clutch 71 controlled by the third lever 82 is turned on. As a result, the carriage transfer/hammer drive rotary shaft 27 rotates once.

Carriage transfer - hammer drive rotary shaft 27 is 1
When rotated, the carriage transport hammer drive cam 28 (see FIG. 3), which is connected to the spline shaft and is transported integrally with the carriage 7, is also rotated.
Rotate. Carriage transfer - hammer drive cam 2
8 has a hammer cam 29 and a screw cam 30 integrally formed, and the peripheral surface of the hammer cam 29 has
The bent portion 31b of the hammer 31 is in contact with the bent portion 31b.

The hammer 31 is mounted on a support shaft 110 fixed to the carriage 7 so as to be rotatable, and is supported by a spring (not shown in FIGS. 7 and 8).
A clockwise rotating force is applied to it, and it is in contact with the stopper 113 when not printing. and,
Carriage Transfer - During the first half rotation of the hammer drive rotary shaft 27 (clockwise rotation in FIGS. 7 and 8), the protrusion of the hammer cam 29 moves toward the hammer 31.
is rotated in the counterclockwise direction as shown in FIG. Record the print data.

As mentioned above, the present invention consists of a type wheel shaft that rotates in a predetermined direction, a type wheel holding member consisting of a bobbin that is fitted onto the outside of the type wheel shaft and connected to the type wheel shaft by a spline shaft, and a type wheel holding member that is held by the holding member and has an outer periphery. A first type ring comprising a type ring having a type part on the side and extrudable in a direction interlinking with the axial direction of the type wheel shaft, and a recessed part integral with the type ring and corresponding to the position of the type part.
a first positioning part having an engaging part; a hammer means for pushing out the type ring and pressing the type part against the paper for printing; and a hammer means that is in a fixed state when the type ring is pushed out and engages with the first engaging part. A second engagement member made of a positioning body or the like having a second engagement part made of a possible convex part or the like.
a positioning part, when the first positioning part is pushed out together with the extrusion of the type ring, and the first engaging part engages with the second engaging part of the second positioning part. , is characterized in that the type wheel is positioned in the extruded state.

In a serial printer, a type ring having a type part on the outer periphery is rotated to a position where a selected type part faces the paper, and a hammer means pushes out the type ring to print on the paper. In some cases, circumferential positional deviation is likely to occur. If the letters are printed while being misaligned, the letters will not line up properly, and moreover, the letters will become partially faded and unclear.

As described above, in the present invention, the circumferential direction of the type wheel is positioned in the extruded state by the engagement relationship between the first positioning part and the second positioning part, so that the printed characters are well arranged. Printing is clear and there are no blurred characters.

In the embodiment, a printer in which the type wheel is arranged horizontally is described, but the present invention can also be applied to a printer in which one or more type wheels are arranged in the vertical direction.

Further, in the above embodiment, a stepped portion was integrally molded at the bottom of the type wheel, and the stepped portion was used as the first positioning portion.
It is also possible to form the first positioning part separately from the type wheel and integrally connect it to the type wheel. In addition,
The shapes of the first and second engaging portions are not limited to the uneven shape, but may be any other shape as long as they can engage with each other and position the type ring.

[Brief explanation of the drawing]

The drawings all relate to a serial printer according to an embodiment of the present invention, and FIG. 1 is an overall perspective view, FIG. 2 is an exploded perspective view showing the relationship between the motor, each rotating shaft, and a group of cam levers, and FIG. 3 is an exploded perspective view. is an exploded perspective view of the carriage, Figure 4 is a schematic diagram showing the rotation transmission system between the motor and each rotating shaft, Figure 5 is an exploded perspective view of the main part of the type wheel group, and Figure 6 is the stepped part of the type wheel. Main part sectional views, FIGS. 7 and 8, for explaining the engaged state of the positioning part
The figure is a cross-sectional side view of the main part showing the relationship between the type ring group and the hammer, Figure 9 is an explanatory diagram showing the forward/reverse clutch, and Figure 10 is an explanatory diagram showing the forward/reverse clutch.
Figures a and b are explanatory diagrams showing the relationship between the first cam, the type selection lever, and the type wheel shift position selection lever;
Figure 11 shows the first, second and third cams controlled by each cam on the type wheel shift rotation axis and type selection axis.
FIG. 13... Type wheel, 13b... Stepped section, 13c...
Groove, 18...Type wheel shaft, 31...Hammer, 112
... Paper, 123 ... Bobbin, 13d ... Positioning body, 13a ... Protrusion.

Claims (1)

[Scope of utility model registration request] a type wheel holding member fitted onto the type wheel set and splined to the type wheel set; a type wheel held by the holding member and having a type portion on its outer periphery which can be pushed out in a direction intersecting the axial direction of the type wheel set; a first positioning member which is integral with the type wheel and has a first engagement portion which corresponds to the position of the type portion; hammer means for pushing the type wheel out and pressing the type portion against paper to print; and a second positioning member which is fixed when the type wheel is pushed out and has a second engagement portion which can engage with the first engagement portion,