JPH0257776B2 - - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION This invention relates to a daisy wheel holding device for a printing machine.

Technical background of the invention and its problems Conventionally, a carrier is provided with a rotary drive body that drives a daisy wheel and a hammer frame that holds a hammer, and the daisy wheel is inserted between the rotary drive body and the hammer frame by opening the hammer frame. There is a device in which the daisy wheel is held against the rotating drive body by a wheel holder that is inserted and resiliently attached to the hammer frame, but even if the hammer frame is opened, the wheel holder protrudes toward the rotating drive body. The space between the wheel holder and the rotary drive body is narrow, making it difficult to attach and detach the daisy wheel between the two. Since a ribbon cassette and other parts are attached to the carrier, there are limits to the opening angle of the hammer frame.

Furthermore, in order to reliably connect the daisy wheel to the rotary drive body, a clamp mechanism for fixing the hammer frame is required, which has the disadvantage of complicating the structure.

Purpose of the Invention The present invention has been made in view of the above points, and it is possible to easily attach and detach the daisy wheel even if the amount of rotation of the hammer frame is limited.
To provide a daisy wheel holding device for a printing machine capable of fixing the movement of a hammer frame with a simple structure.

SUMMARY OF THE INVENTION This invention provides a rotary drive body in a carrier, attaches a hammer frame rotatably in a direction away from the rotary drive body, and has a wheel on the hammer frame that resiliently presses a daisy wheel against the rotary drive body. The presser foot is provided to be rotatable and move forward and backward in the axial direction, and furthermore, an operating lever and an operating body are interlocked and connected to the hammer frame, and the stopper shaft provided on the carrier is moved to the operating lever according to the rotating position of the operating lever. This maintains the hammer frame in a state where it approaches or retreats from the rotary drive body, and when the hammer frame moves away from the rotary drive body, the actuating body is linked to the rotational movement of the operating lever and the wheel is moved. Even if the presser foot is retracted and the rotation angle of the hammer frame is restricted, a wide space is left between the rotary drive body and the wheel presser to allow easy attachment and detachment of the daisy wheel. The hammer frame can be fixed in any position with a simple structure of simply engaging the stopper shaft with the operating lever of the hammer frame.

Embodiment of the Invention An embodiment of the invention will be described based on the drawings.
Both ends of a platen 2, a carrier shaft 3, and a guide rail 4 are held by opposing frames 1. A step motor 8 is fixed to a carrier 5 which is slidably held by a carrier shaft 3 and a guide rail 4 and which transmits rotational force via a gear 6 to a gear 7 which is a rotational drive body. A locking portion 10 is formed on one surface of the gear 7 to prevent the daisy wheel 9 from rotating. Further, a hammer frame 11 is attached to the carrier 5 so as to be rotatable about a fulcrum 13 while being biased by a spring 12 in a direction away from the gear 7 . This hammer frame 11 has a printing hammer 14.
is urged in the return direction by a spring 15 and is rotatably mounted. A solenoid 16, which is a drive unit for striking the printing hammer 14, is also fixed to the hammer frame 11.

Next, a shaft 17 is held in the hammer frame 11 so as to be slidable while being biased in one direction by a spring 18, and a wheel holder 19 is rotatably held at the tip of the shaft 17 via a slide bearing 20. . In addition, the hammer frame 11 includes
The operating lever 21 is biased toward the gear 7 (clockwise) by the torsion spring 22, and the supporting shaft 23
It is mounted so that it can rotate freely around the
An actuating body 25 facing the pressing piece 24 of the operating lever 21 is rotatably mounted around a support shaft 26 . One end of this actuating body 25 is connected to the shaft 17.
It is in contact with a ring 27 fixed to the rear end of.

The operation lever 21 is formed with a U-shaped locking recess 28 and a V-shaped locking recess 29. Further, the carrier 5 has a locking recess 2.
A stopper shaft 30 that engages with the plates 8 and 29 is installed parallel to the axis of the platen 2.

The daisy wheel 9 is housed and protected in a cassette case 9a which has a large opening at the center of both sides.

In this configuration, the operating lever 21 is biased clockwise by the force of the torsion spring 22, and the locking recess 28 and the stopper shaft 30 engage with each other as shown in FIGS. 1 and 2. In this state, the hammer frame 11 and the operating lever 21 receive a counterclockwise moment about the fulcrum 13 due to the force of the spring 12, but the operating lever 21 is pushed back from the stopper shaft 30 on a line passing through the center of the stopper shaft 30. Because of the force F, the counterclockwise movement of the hammer frame 11 is locked, and the daisy wheel 9 is held between the gear 7 and the wheel holder 19. Further, in this state, component forces F ₁ and F ₂ are generated from the reaction force F, and the engagement force between the locking recess 28 and the stopper shaft 30 can be further strengthened by the component force F ₁ .

When the operating lever 21 is rotated counterclockwise against this component force F ₁ and the force of the torsion spring 22, the locking recess 28 and the stopper shaft 30 are disengaged. Therefore, the hammer frame 11 rotates counterclockwise around the fulcrum 13 due to the force of the spring 12, and the operating lever 21 rotates the actuating body 25 counterclockwise as shown in FIGS. 3 and 4. ,
The wheel holder 19 is retracted from the gear 7 together with the shaft 17.

In this way, not only does the hammer frame 11 separate from the gear 7, but also the wheel presser 19 moves relative to the hammer frame 11 and retreats from the gear 7, so even if the rotation angle of the hammer frame 11 is reduced, the gear 7 A wide space can be provided between the wheel holder 19 and the wheel holder 19. Therefore, the daisy wheel 9 can be attached and detached very easily. Further, in this state, the stopper shaft 30 engages with the locking recess 29, so that the rotation angle of the operating lever 21 and the hammer frame 11 is determined.

Then, when a clockwise operating force is applied to the operating lever 21, a reaction force R acts on the contact portion between the stopper shaft 30 and one edge 31 of the locking recess 29, and from this reaction force R, a component force R ₁ , R ₂ are generated, and R ₂ acts on the center of the support shaft 23 to give a moment to the hammer frame 11 in the clockwise direction about the support shaft 13 . As a result, the hammer frame 11 is rotated toward the platen 2 against the force of the spring 12, and the locking recess 28 of the operating lever 21 and the stopper shaft 30 are engaged again. The wheel holder 19 is returned together with the shaft 17 by the force of the spring 18, and presses the stage wheel 9 against the gear 7.

In this way, the hammer frame 11 can be easily moved by using the operating lever 21 attached to the hammer frame 11 and engaging the stopper shaft 30 with the locking recesses 28 and 29 formed in the operating lever 21.
can be fixed at any position shown in FIGS. 1 and 2 or 3 and 4.

Note that by turning the operating lever 21, the locking recess 28
and the stopper shaft 30, and then release the operation lever 2.
Since the hammer frame 11 can be rotated even if the hammer frame 11 is pulled toward the user, the spring 30 may be omitted.

Effects of the Invention Since the present invention is configured as described above, when the hammer frame is separated from the rotary driving body, the wheel holder is moved relative to the hammer frame to move between the wheel holder and the rotary driving body. Therefore, it is possible to easily attach and detach the daisy wheel, and furthermore, it is possible to limit the amount of movement of the hammer frame and downsize the carrier. The hammer frame can be fixed at any position by engaging the operating lever with the stopper shaft, and the clamping structure of the hammer frame can therefore be simplified.

[Brief explanation of drawings]

The drawings show one embodiment of the invention.
The figure is a longitudinal side view showing the daisy wheel set, Fig. 2 is a partially enlarged longitudinal side view, Fig. 3 is a longitudinal side view showing the hammer frame separated from the gear, and Fig. 4 is a longitudinal side view showing the condition in which the daisy wheel is set. It is a vertical side view which enlarged a part. 2...Platen, 5...Carrier, 7...Gear (rotation drive body), 9...Daisy wheel, 11...
...Hammer frame, 14...Printing hammer, 16...
...Solenoid (drive part), 19...Wheel holder,
21... Operating lever, 25... Operating body, 28,2
9...Latching recess, 30...Stopper shaft.

Claims (1)

[Claims] 1. A rotary drive body to which a daisy wheel is detachably connected to a carrier that moves along a platen is provided, and a hammer frame that holds a printing hammer and a drive unit that drives the printing hammer is attached to the rotary drive body. The wheel holder is mounted so as to be rotatable toward and away from the hammer frame, and the wheel holder, which is urged in one direction by the hammer frame and clamps the daisy wheel between it and the rotary drive body, is rotatable and can move back and forth in the axial direction. a control lever is attached to the hammer frame so as to be rotatable by urging it in the direction of the rotary drive body, and an actuator is attached to the hammer frame to move the wheel holder away from the rotary body in conjunction with the control lever; Two locking recesses are formed on the back surface of the control lever at different radii from the center of rotation of the control lever, and the locking recesses are selectively engaged with one of the locking recesses. Daisy of the printing machine, characterized in that the carrier is provided with a stopper shaft that presses the hammer frame toward the rotary drive body when engaged and determines the range of rotation of the hammer frame when engaged with the other locking recess. Wheel holding device.