JPH0129084Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a carriage mechanism for an electronic typewriter.

Conventionally, in the carriage mechanism of this type of electronic typewriter, a petal-shaped printing wheel is provided in a detachable and replaceable manner, and there are various types of attachment/detachment means. First, as an example, a drive plate that holds the petal-shaped printing wheel is provided on the motor shaft, and the motor is mounted in an up-and-down manner to change the position and direction of the drive plate, thereby changing the set position of the petal-shaped printing wheel. The attachment/detachment position is selected. This type of equipment consists of a motor, motor shaft, drive plate, and other parts that are raised and lowered as one body.
Moreover, since the setting position must be determined accurately, the structure is complicated, the number of parts increases, and structural stability is low.

Next, in another conventional example, a petal-shaped printing wheel is housed in a cassette, a drive plate connected to a motor is provided so as to be able to move forward and backward, and the drive plate is moved by dropping the cassette with the drive plate retracted. There are structures that move us forward. Positioning in the rotational direction is performed by a pin and an engagement hole, and the pin is provided elastically so that it engages when the drive plate is rotated to a certain extent. Therefore, it has the advantage that there are few moving parts during attachment and detachment, and the structure is relatively simple, but the positioning in the rotational direction is determined by a single pin and an engagement hole, and perfect positioning is not possible. Because there is a time variation in the time it takes to complete the process, and because this part will eventually become the driving force transmission part,
It has drawbacks such as lack of stability and durability of power transmission.

In addition, in all of the conventional structures, the motor and the detachable structure for the petal-shaped printing wheel are located in the same direction on the carriage frame, so there is not enough space, and the mounting structure for the ribbon mechanism is quite difficult. Things are getting complicated. Furthermore, an expensive motor with a small advance angle must be used, and if a stepping motor or the like is used, it is difficult to print at high speed due to vibration damping. There is a problem with the decline.

This idea was devised in view of these points, and the petal-shaped printing ring is extremely easy to attach and detach.
The object of the present invention is to provide a carriage mechanism for an electronic typewriter that can stabilize the set state when set to a printable state.

This invention has a holder that can be rotated up and down with respect to the holder that holds the petal-shaped printing wheel, so there is a large space for installing and removing the petal-shaped printing wheel, making it easy to operate. At the same time, the hook body rotatably attached to the holder is biased in the direction such that the engaging part of the hook body engages with the stopper provided on the carriage frame, and the two-stage By selectively engaging the engaging portion formed in the stopper with the stopper, the holder can be fixed in either a position where the petal-shaped printing ring is pressed against the holder or a position where it is separated from the holder; When setting, the holder presses the petal-shaped printing ring against the holder with a constant pressure to obtain a stable set state, and also rotates the holder to move the petal-shaped printing ring away from the holder. This is done by releasing the engaging part from the stopper by pressing the lever on the hook body, but although the holder is biased in the direction away from the holding body, the lever formed on the hook body is pressed in the direction in which the holder is pressed. Since the biasing direction is opposite to the biasing direction of
Moreover, it is configured so that it can be easily operated with one hand.

An embodiment of this invention will be described based on the drawings. First, a cylindrical platen 1 installed horizontally.
A carriage frame 2 is provided that reciprocates in the left-right direction along the axis of the carriage frame 2. A motor 3, which is a drive unit such as a pulse motor, is attached to one vertical side of the carriage frame 2. A motor shaft 4 projects from the other side of the Tsuji frame 2, and a pulley 5 is attached to this motor shaft 4. A fixed shaft 6 having a tapered tip is attached above the carriage frame 2, and a timing pulley 7, which is a holder, is rotatably attached to the fixed shaft 6. On one end surface of the timing pulley 7, protrusions 8 are provided at positions dividing the circumference into 25 equal parts, and on the outer periphery of these protrusions 8 there are 25 indexes whose positions coincide with each protrusion 8. A hole 9 is provided. Furthermore, timing belt teeth 11 are formed on the other surface of the timing pulley 7, leaving a flange 10. Timing belt teeth (not shown) are also formed on the small-diameter pulley 5, and the timing belt 12 is tensioned with a predetermined tension between the timing belt teeth of the pulley 5 and the large-diameter timing belt teeth 11. It is set up.

A petal-shaped printing ring 13 is then provided.
The petal-shaped printing wheel 13 is provided with a plurality of type legs 15 each having a type 14 formed at its tip. Assume now that the number of printed characters 14 is 100. A center hole 16 is provided at the center of this petal-shaped printing ring 13.
A metal core 17 having a diameter is embedded therein, and 25 recesses 18 that engage with the protrusions 8 of the timing pulley 7 are formed on one side. Further, a single index hole 19 is formed so as to overlap the index hole 9.

Next, a support shaft 20 is provided below the carriage frame 2, and this support shaft 20 has a holder 2.
1 is attached to a position facing the timing pulley 7 and a position away from the timing pulley 7 so as to be freely rotatable up and down. Further, a stopper 22 is fixed to the horizontal surface of the carriage frame 2. A holding edge 23 for temporarily holding the petal-shaped printing ring 13 is formed at the lower end of the holder 21, and a pressure shaft 24 is provided at the middle part. That is, a pressing body 25 is fixed to one end of the pressure shaft 24 and urged toward the timing pulley 7 by a compression spring 26, and a retaining ring 27 for preventing slippage is provided at the other end. A pair of left and right reinforcing plates 28 are fixed to the holder 21, and a hammer shaft 30 with a hammer 29 welded to these reinforcing plates 28 is rotated about its axis by a center shaft 31 and a center screw 32. It is pivoted for free movement. Furthermore, a hook body 34 integrally formed with a lever portion 33 extending upward is rotatably connected to the reinforcing plate 28 by a support shaft 41. Two stages of engaging portions 35 and 36 that are engaged with each other are formed. A spring 37 is provided between the reinforcing plate 28 and the hook body 34 for biasing the hook body 34 in a direction in which the engaging portions 35 and 36 engage with the stopper 22.
Further, a pair of left and right springs 38 are tensioned between the reinforcing plate 28 and the stopper 22 for biasing the holder 21 in the direction of rotation away from the timing pulley 7.

Further, a light emitting diode 39 and a phototransistor 40 are provided on the holder 21 and the carriage frame 2 at positions corresponding to the index holes 9 and 19.

In such a configuration, when attaching or replacing the petal-shaped printing wheel 13, the lever portion 33 of the hook body 34 is pressed in the direction of the platen 1 from the set state shown in FIG. As a result, the hook body 34
rotates around the axis of the support shaft 41 while resisting the tensile force of the spring 37, and the engagement between the first stage engagement portion 35 and the stopper 22 is disengaged. When the engagement portion 35 and the stopper 22 are disengaged, the holder 21 rotates around the axis of the support shaft 20 in a direction away from the timing pulley 7 due to the tensile force of the spring 38.
When the engagement part 35 and the stopper 22 are disengaged and the holder 21 has rotated a little, when you release your finger from the lever part 33, the tensile force of the spring 37 moves the lever to the second stage as shown in FIG. The engaging portion 36 and the stopper 22 engage with each other. As a result, the holder 21 is fixed in a state where the upper space is wide open, and the petal-shaped printing ring 13 is dropped into this part. As a result, the petal-shaped printing wheel 13 is temporarily held by the holding edge 23. Next, push the holder 21 and move the timing pulley 7 while resisting the tensile force of the spring 38.
When rotated in the direction, the side surface of the engaging portion 36 slides while being pressed against the stopper 22, and the engaging portion 36 and the stopper 22 are disengaged, and the engaging portion 35 and the stopper 22 are engaged. The state shown in FIG. 2 is then reached. In this state, a force acting on the holder 21 in the direction of separating it from the timing pulley 7 due to the tensile force of the spring 38 acts on the holder 21, but the engaging portion 35 and the stopper 22 are reliably engaged due to the tensile force of the spring 37, and the holder 21 This prevents the holder 21 from rotating in the direction away from the timing pulley 7, and therefore the up-and-down rotation movement of the holder 21 is reliably fixed. At this time, the fixing shaft 6 fits into the center hole 16 of the petal-shaped printing wheel 13 to achieve alignment, and the lower end of the petal-shaped printing wheel 13 rises above the holding edge 23.
Enables smooth rotation. It is also pressed by the pressure shaft 24 and held between it and the timing pulley 7. When the timing pulley 7 is rotated by the drive of the motor 3, the protrusion 8 and the recess 1 are immediately connected to each other.
8 are engaged with each other, and the index hole 19 matches one of the index holes 9. As a result, the positioning of the petal-shaped printing wheel 13 with the timing pulley 7 corresponds to the position of the position type 14 of the motor 3, and printing by the hammer 29 is performed at an accurate position. , the index holes 9 and 19 also ensure the selection of type 14. In addition, the driving force is generated by the protrusions 8 arranged on the circumference.
Since the process is carried out by , it is carried out reliably in a well-balanced state, and it is also highly durable.

Since the rotation speed of the motor 3 is reduced by the diameter ratio of the pulley 5 and the timing pulley 7, it is possible to make the advance angle of the motor 3 considerably larger than the advance angle based on the arrangement spacing of the printed characters 14. This allows the motor 3 itself to be manufactured relatively inexpensively. Furthermore, by tensioning the timing belt 12 with a predetermined tension, it is possible to increase the frictional force in the transmission system from the motor 3 to the timing pulley 7, thereby making the vibration damping of the motor 3 nearly non-existent. It is also possible.

Further, since the motor 3 is provided so as to protrude from one side of the carriage frame 2, the space on the holder 21 side becomes large, and the installation of the printing ribbon mechanism etc. becomes extremely easy.

In this invention, as mentioned above, the holder is provided so that it can be rotated up and down with respect to the holder, so the space for loading and unloading the petal-shaped printing wheel is enlarged, and its operation can be performed easily. Simply operate to disengage the engaging part of the hook attached to the holder and the stopper provided on the carriage frame.
By automatically rotating the holder in the direction away from the holder, a state in which the petal-shaped printing wheel can be attached can be easily obtained, and in particular, the force acting on the hook body at this time is This is the pressing force applied to the lever, and the direction of application of this force is opposite to the direction in which the holder is biased, so it is possible to eliminate the risk of the holder suddenly opening by gradually relaxing the pressing force on the lever. It is safe, easy to operate with one hand, and when set up,
By elastically engaging the engaging part of the hook body with the stopper, the up-and-down rotational movement of the holder is reliably fixed, and the petal-shaped printing wheel is pressed against the holder with a constant pressing force, making it stable. This has the effect of being able to maintain the set state.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a partially cutaway perspective view, Figure 2 is a vertical side view when set, Figure 3 is a vertical side view when opened, and Figure 4 is a vertical side view when opened.
Figure 5 is a rear view of the holder, Figure 5 is a vertical side view of the timing pulley, Figure 6 is its front view, Figure 7 is its back view, Figure 8 is a vertical side view of the petal-shaped printing wheel, and Figure 9. is its rear view. 1...Platen, 2...Carriage frame,
3... Motor (drive unit), 7... Timing pulley (holding body), 13... Petal-shaped printing wheel, 21...
Holder, 22... stopper, 33... lever portion, 34... hook body, 35... engaging portion.

Claims (1)

[Scope of utility model registration request] A drive section is attached below the platen side of the carriage frame that moves along the axial direction of the platen, and a holder that holds the petal-shaped printing wheel and is connected to the drive section is attached to the platen of the carriage frame. A holder is mounted on the front side opposite to the holder and rotates up and down so that it faces the holder and is located at a position where the petal-shaped printing ring is pressed against the holder and a position where it is separated from the holder. It is attached to the carriage frame by being biased in a direction away from the holding body, and the carriage frame is provided with a stopper, and has a lever portion that projects upward from the center of rotation, and is located above the stopper. An electronic device characterized in that a hook body having a two-stage engaging portion that selectively engages with the holder is rotatably connected to the holder by urging the hook body in a direction in which the engaging portion engages with the stopper. Typewriter carriage mechanism.