JPH0247019Y2 - - Google Patents

Description

[Detailed description of the invention] Purpose of the invention (industrial application field) This invention moves a carriage on which a type wheel having a plurality of type elements is mounted along a platen, and moves the type wheel using a type selection motor. This typewriter relates to a typewriter in which a type element is selected by rotating the typewriter, and then the type element is struck, and the type element and the printing ribbon cooperate to print on the printing paper on the platen.

(Prior Art) Conventionally, this type of device has a motor 3 mounted on a carriage 1 movably supported along a platen (not shown), as shown in FIG. 9, for example. By rotationally driving the type wheel 4 by the , type elements are selected. In this conventional device, the actuating piece 6 attached to the end of the motor shaft 3a of the motor 3 cooperates with a sensor 7 consisting of a photointerrupter provided on the carriage 1, so that the type wheel 4 On the other hand, as the carriage 1 moves, the origin position of the carriage 1 is detected by a micro switch 9 on the typewriter frame 8 with which a part of the carriage 1 is engaged. .

However, in this conventional configuration, expensive detection elements such as a photointerrupter and a microswitch are used to detect the origin positions of the type wheel 4 and the carriage 1, respectively, so there is a problem that the manufacturing cost of the detection device increases. It was hot.

(Purpose) This invention was made to solve the above problem, and its purpose is to provide an origin position detection device that can reliably detect the origin position of the type wheel and carriage and can be manufactured at low cost. It's about doing.

Structure of the invention (means for solving the problems) In order to solve the above problems, this invention includes one detection switch having a leaf-shaped contact point, and a detection switch that moves as the carriage moves. Connect and disconnect the contacts of the detection switch.
a first actuating piece for turning ON and OFF and thereby detecting the origin position of the carriage; a base position detection member provided on the type wheel; and a rotational trajectory of the base position detection member provided on the carriage. an actuating member movable between an inactive position further outward and an actuating position inward from the rotation locus; and an actuating member provided on the frame of the typewriter, after the detection switch is turned on by the first actuating piece. a second actuating piece that engages with the actuating member to move the actuating member into the rotation locus of the base position detecting member when the carriage overruns the base position detecting member; When the base position detection member engages with the actuating member as the type wheel rotates after being moved into the rotation locus, the type selection motor is stepped out based on the engagement, whereby the type The wheel is arranged at a base position, one of the first actuating piece and the detection switch is disposed on the carriage, and the other is disposed on the frame, and the detection switch is disposed on the carriage. The contact point of the switch extends obliquely to the direction of carriage movement.

(Function) Therefore, when the first actuating piece engages the detection switch as the carriage moves, the detection switch is turned on and the home position of the carriage is detected, and as the carriage overruns thereafter, The second actuating piece engages with the actuating member, and the actuating member is moved within the rotation locus of the base position detection member. Thereafter, when the base position detection member is engaged with the actuating member as the type wheel rotates, the type selection motor is stepped out based on the engagement, and the type wheel is placed at the base position. Since the contact point of the detection switch extends obliquely to the direction of carriage movement, the amount of deflection of the contact point when the detection switch is turned on and off can be reduced, extending the service life. Since the origin position of the carriage and the origin position of the type wheel can be detected with a single detection switch, manufacturing is possible at low cost.

(Example) An example of a typewriter embodying this invention will be described below with reference to the drawings.

As shown in FIG. 2, a pair of front and rear connecting frames 14, 15 having a substantially U-shaped cross section are constructed and fixed between the left and right side walls 12, 13 of the frame 11. As shown in FIG. 2, a keyboard B having a large number of keys K arranged in a row is disposed further forward of the front connecting frame 15. Further, a platen 16 is rotatably supported between both side walls 12 and 13 on the rear connecting frame 14. Then, by rotating the platen 16 with printing paper (not shown) circulating around the platen 16, a feeding force is applied to the printing paper. A guide shaft 1 is provided on the frame 11 so as to extend parallel to the platen 16.
7 is installed, and a carriage 18 formed by bending a metal plate is supported on the guide shaft 17 at the rear thereof so as to be movable along the platen 6. Further, a guide piece 19 provided at the front of the carriage 18 is movably fitted into the upper part of the front connecting frame 15.

As shown in FIG. 2, a motor 20 for carriage movement is attached to the right side of the rear surface of the rear connecting frame 14, and a drive gear 21, a driven gear A drive pulley 23 is provided which is rotationally driven via a drive pulley 22 . A wire 24 as shown in FIG.
is wound around, and a portion of its wire 24 is fixed to the carriage 18. As the driving pulley 23 rotates, the driven pulley and the wire 2
4, a carriage 18 is moved along the platen 16.

The motor 20 for moving the carriage is A.
It is composed of a step motor having four stator excitation phases consisting of phases -D, and the carriage 18 is moved from the leftmost end to the rightmost end of its movement range by rotation for 1200 steps.

As shown in FIGS. 3 and 4, a type selection motor 26 consisting of a step motor is supported at the front of a motor bracket 25 fixed to the rear of the carriage 18.
A driven gear 27 is rotatably supported on the rear side, and as the type selection motor 26 rotates, the driven gear 27 engages with a driving gear 28 on a motor shaft extending through the motor bracket 25.
is rotated forward and backward. A type support 30 having a large number of radially extending type elements 30a (96 in this embodiment) is rotatably supported on a shaft 29 protruding from the center of the rear surface of the driven gear 27, and each type element 3
Type letters (not shown) are formed at the outer end of Oa. The type support 30 is housed in a flat box-shaped case 35, and can be attached to and removed from the shaft 29 together with the case 35. Further, the type carrier 30, the driven gear 27 and the shaft 2
9 constitutes a type wheel W.

A printing hammer 33 is rotatably supported by a hammer shaft 32 on the hammer bracket 31 to which the motor bracket 25 is fixed. It has become possible to hit it.
A ribbon cassette 34 shown in FIGS. 2 and 4 is mounted on the carriage 18, and a part of the printing ribbon R is exposed in a stretched state between the guide portions at both ends of the rear part of the ribbon cassette 34, and is exposed on the printing surface of the platen 16. They are placed opposite each other.

Then, by rotationally driving the type wheel W based on the print signal, the type characters of a predetermined type element 30a are selectively arranged at a position facing the printing surface of the platen 16. In this embodiment, one character is selected by two steps of rotation of the character selection motor 26. In this state, the printing hammer 31 shown in FIG.
When is activated, characters are printed on the printing paper via the printing ribbon R.

As shown in FIGS. 4 and 5, a detection protrusion 36 as a base position detection member for detecting the base point of the type wheel W is integrally formed on the front surface of the driven gear 27. Further, the motor bracket 25
On the rear surface, an actuation member 37 formed in the shape of four arms from a synthetic resin material is rotatably supported at the free end of its first arm portion 38, and the detection protrusion 36 is supported at the free end of the second arm portion 39. An engaging portion 40 that can be engaged and disengaged is formed. A spring 43 is hung between the free end of the third arm 41 of the actuating member 37 and a spring hook 42 projecting from the motor bracket 25. The spring 43 biases the operating member 37 to rotate counterclockwise in FIG. It is placed in a non-active position outside the trajectory. Note that the fourth arm portion 44 is formed in a thin plate shape and extends downward from the intermediate portion of the actuating member 37. This fourth
The carriage 18 is positioned opposite the free end of the arm 44.
A through hole 45 is formed in.

As shown in FIGS. 3 and 5, the carriage 18
An origin detection switch 47 having a pair of leaf-shaped contacts 46 extending parallel to each other is mounted on the support piece 18a protruding from the left side of the switch 18 with a screw 47a, and the outer contact 46 has a substantially L-shape. An engagement piece 48 is provided in a protruding manner. Further, each contact point 46 is arranged at a position that is obliquely directed at an angle of about 45 degrees to the right with respect to the moving direction of the carriage 18.

As shown in Figures 2, 3, 5 and 6, frame 1
A detection member 49 formed by bending a metal plate is attached to the left side wall 12 of 1, and the detection member 49 is integrally formed with first and second actuating pieces 50 and 51 that protrude to the right. . As shown in FIG. 6, as the carriage 18 moves, the first operating piece 50 engages and disengages from the engaging piece 48 of the detection switch 47, and the detection switch 47 is activated via each contact 46.
Turns ON and OFF. Further, the detection switch 47
As the carriage 18 overruns after the switch is turned on, the second operating piece 51 moves into the through hole
The actuating member 37 is rotated clockwise in FIG. 4 against the biasing force of the spring 43, and the engaging portion 40 engages with the fourth arm portion 44 of the actuating member 37. 36 to an operating position located within the rotational trajectory of 36. In this state, the type wheel W is rotated clockwise in the clockwise direction in FIG. The rotation of the type wheel W is stopped.

Next, the electric block circuit in this embodiment will be explained with reference to FIG. In the same figure,
52 is a central processing unit (hereinafter referred to as CPU), and a read-only memory (ROM) 53 and a random access memory (RAM) 54 are connected to the CPU 52, which stores a program for suppressing the operation of the entire typewriter. has been done.

When a carriage return signal or the like is input by operating a predetermined key on the keyboard B, the CPU 52 reads the program from the ROM 53 and outputs a drive signal to the carriage moving motor 20 via the motor driver 55. With this movement of the carriage 18 to the left by the motor 20,
The engagement piece 48 of the detection switch 47 is the first actuation piece 5
0, the detection switch 47
A detection signal is input to the CPU 52 from the CPU 52 . and,
In this state, the CPU 52
A drive signal is output to the type selection motor 26 via 6.

Next, the operation of the typewriter constructed as described above will be explained mainly with reference to FIGS. 7 and 8. In addition,
In this embodiment, as shown in FIG. 8, the CD phase of the carriage moving motor 20 is in an excited state, the detection switch 47 is turned on, and the origin of the carriage 18 is detected. . When each excitation phase is excited in the order of AD, CD, BC, and AB, the carriage 18 is moved to the right in FIG. be moved towards

Now, when detecting the origin of the carriage 18 and the type wheel W, first, follow the steps shown in FIG.
In step S1, it is determined whether the detection switch 47 is turned on or not, and if the result is NO, the process proceeds to step S3.
Proceed to. On the other hand, if the result is YES, the carriage 18 is moved to the 30th position of the motor 20 in the next step S2.
It is moved to the right in FIG. 2 by an amount equivalent to a step. In the next step S3, the detection switch 47 is turned on,
It is confirmed that it is OFF, and if it is ON, the process advances to step S10 and error processing is performed using a buzzer or the like.
If it is OFF, the process proceeds to step S4, where the character selection motor 26 is rotated twice in a predetermined direction in order to reliably connect the character carrier 30 to the shaft 29 on the driven gear 27.

Next, the processes from step S5 to step S9 are repeated. That is, in step S6, it is determined whether or not the detection switch 47 is turned on each time the carriage 18 is moved to the left in FIGS. 2 and 6 by an amount equivalent to one step of the motor 20. Here, when the engagement piece 48 of the detection switch 47 is engaged with the first actuation piece 50 as the carriage 18 moves leftward, the detection switch 47 is turned ON and the origin position of the carriage 18 is changed. Detected.

Therefore, in the next step S7, the motor 20 is
It is determined in step S7 whether or not the AB phase is in an excited state. Subsequently, in step S8, it is determined again whether the detection switch 47 is ON or OFF. Normally, the detection switch 47 is turned ON when the CD phase is excited as the carriage 18 moves to the left, so here the determination is ON, and steps S9 and S5 are executed to turn the detection switch 47 ON. Nevertheless, the carriage 18 is moved one step further to the left. When the carriage 18 has been moved two steps to the left since the detection switch 47 was turned on, the AB phase of the motor 20 is excited.
Therefore, the result of the determination in step S7 is YES,
At the next step S8, the detection switch 47 is turned ON again.
It is determined whether the Normally, the detection switch 47 is in the ON state here, so in the next step S11, the carriage 18 is moved four steps to the left.

When the carriage 18 is moved four steps to the right, as shown in FIG. 6, since the detection switch 47 is normally away from the first actuating piece 50 and is in the OFF state, the determination in step S12 is YES. , proceed to the next step S14.

On the other hand, if the determination in step S9 is NO, that is, if the detection switch 47 is not turned on even though the motor 20 has been driven 1200 steps, the above-described error processing is performed in the next step S10. In this example, this means that motor 20
is driven 1200 steps, the carriage 18
Since the carriage 18 is set to be able to move over its entire range of movement, if the detection switch 47 still does not turn on even though the carriage 18 has been moved over the entire range, there is an abnormality somewhere. This is because it is determined that this has occurred. Also,
If the determination in step S12 is NO, that is, if the detection switch 47 is in the ON state, steps S11 and S12 are repeated four more times, and the detection switch 47 is still in the ON state.
If it is not turned off, the determination in step S13 becomes YES, and the above-described error processing is performed in the next step S10.

Now, in step S14, the carriage 18 is moved to the left by 11 steps S of the motor 20, and the detection switch 47 is activated by the first actuating piece 50.
After being turned on, the detection switch 47 is overrun beyond the ON position.

As the carriage 18 overruns, the fourth arm portion 44 of the actuating member 37 is engaged with the second actuating piece 51, and as a result of this engagement, the actuating member 37 moves against the biasing force of the spring 43. It is rotated clockwise in FIG. 4, and the engaging portion 40 is placed within the rotation locus of the detection protrusion 36.

Note that, since the fourth arm portion 44 is formed of a synthetic resin material into a thin plate shape, the second actuating piece 5
1 can be absorbed by its own elasticity, and the risk of breakage during engagement can be prevented.

Thereafter, in step S15, while the type selection motor 26 rotates the type wheel W in the clockwise direction in FIG. Based on this, the type selection motor 26 is stepped out and stopped. This action places the type wheel W at the base position.

Next, in step S16, the type wheel W is reversed by 12 characters in the counterclockwise direction in FIG. W is placed at the origin position for type selection. Then step
In S17, the carriage 18 is moved rightward to the left end position of the printing range, that is, the left margin position. With this movement, the fourth arm portion 44 of the actuating member 37 separates from the second actuating piece 51, and the actuating member 37 is rotated back by the biasing force of the spring 43, so that the engaging portion 40 is moved to a non-active position outside the rotation locus. Further, as the carriage 18 moves to the right, the engagement piece 48 of the detection switch 47 separates from the first operating piece 51, and the detection switch 47 is turned OFF.

As described above, in this embodiment, since the origin of the carriage 18 and the origin of the type wheel 30 can be detected by one detection switch 47, the structure can be simplified and manufactured at low cost. In addition, as shown in FIG. 6, since the contact 46 of the detection switch 47 is arranged at a position diagonal to the direction of carriage movement, the carriage 1
8 can be overrun, and the life of the contact 46 can be extended by reducing the amount of deflection of the contact 46 due to engagement and disengagement with the first actuating piece 50. Furthermore, since the first and second actuating pieces 50 and 51 are integrally formed and attached to the frame 11, the structure and assembly thereof can be further simplified.

Note that this invention is not limited to the above embodiment; for example, the detection switch 47 is
It is also possible to arbitrarily change the structure of each part without departing from the spirit of this invention, such as providing the first operating piece 50 on the carriage 18.

Effects of the invention As detailed above, in this invention, the contact point of the detection switch extends obliquely to the direction of carriage movement, so the detection switch can be turned on or off.
It has the advantage of being able to extend its life by reducing the amount of deflection of the contact when it is OFF, and being able to detect the carriage home position and the type wheel base position with a single detection switch, making it possible to manufacture it at low cost. It has a great effect.

[Brief explanation of the drawing]

Figure 1 is an electrical block diagram of a typewriter embodying this idea, Figure 2 is a plan view of the typewriter, Figure 3 is a left side view, Figure 4 is a rear view of the carriage, and Figure 5 is the origin detection. An exploded perspective view of the main parts of the device,
FIG. 6 is a partially enlarged plan view showing the ON and OFF states of the detection switch, FIG. 7 is a flowchart, and FIG. 8 is an explanatory diagram of the operation when detecting the origin. FIG. 9 is a partial plan view showing a conventional example. In the figure, 11 is a frame, 16 is a platen, 18 is a carriage, 26 is a type selection motor,
30 is a type wheel, 30a is a type element, 36 is a detection protrusion as a base position detection member, 37 is an actuation member, 46 is a contact, 47 is a detection switch, 50 is a first actuation piece, and 51 is a second actuation piece. , R is a printing ribbon.

Claims (1)

[Claims for Utility Model Registration] Type wheel W having a plurality of type elements 30a
The carriage 18 on which is mounted is moved along the platen 16, and the type selection motor 26 rotates the type wheel W to select the type element 30a.
In a typewriter in which the type element 30a is struck after selecting the type element 30a, and the type element 30a and the printing ribbon R work together to print on the printing paper on the platen 16, the leaf-shaped contacts 46 are pressed. As the carriage 18 moves, the detection switch 47 engages and disengages from the contact 46 of the detection switch 47 to turn the detection switch 47 ON and OFF.
The first actuating piece 50 for detecting the origin position of 8
a base position detection member 36 provided on the type wheel W; and a lower operating position located on the outer side of the rotational trajectory of the base position detection member 36 and an operating position on the inner side of the rotational trajectory provided on the carriage 18. an actuating member 37 movable between; and an actuating member 37 provided on the frame 11 of the typewriter, the first actuating piece 50 detecting the detection switch 47.
and a second actuating piece 51 that engages with the actuating member 37 and moves the actuating member 37 within the rotation locus of the base position detecting member 36 as the carriage 18 overruns after being turned on. , After the actuating member 37 is moved into the rotation locus of the base position detecting member 36, the base position detecting member 36 is moved as the type wheel W rotates.
When engaged with the actuating member 37, the type selection motor 26 is stepped out based on the engagement, so that the type wheel W is placed at the base position, and the first actuating piece 50 and the detection switch 47 to the carriage 18.
and the other side is placed on the frame 11.
An origin position detection device for a typewriter, characterized in that the contact point 46 of the detection switch 47 extends obliquely to the carriage movement direction.