JPH0417151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a flying printing wheel line printer that can prevent double printing or double striking.

Prior Art A conventional so-called flying printing wheel line printer has a swingable printing hammer that cooperates with a rotating printing wheel, a pawl wheel that rotates in synchronization with the printing wheel, and an electromagnet that attracts and swings the printer. armature lever;
It is pivoted to the armature lever with a limited swing range.
It has an actuation lever that swings to operate the printing hammer when the armature lever is actuated, and when the electromagnet is energized by the printing command signal and the armature lever is swung, the armature lever is activated. The pivoted operating lever enters the operating range of the ratchet wheel, the engaging claw provided on the operating lever comes into contact with the engaging claw of the ratchet wheel, and the operating lever is swung to operate the printing hammer;
It is designed to print as desired. Immediately after the above, the armature lever and the operating lever are returned to their initial positions by springs that act separately.

Problems with the Prior Art In the printers described above, when the armature lever after operation causes damped vibration due to the influence of the residual magnetism of the electromagnet, the armature lever falls within the operating range (rotational trajectory) of the ratchet wheel. In this case, the actuating lever is actuated again by the ratchet wheel to actuate the printing hammer, resulting in the disadvantage that double printing errors, so-called overstrike, are likely to occur.

OBJECTS OF THE INVENTION An object of the present invention is to provide a flying type printing wheel line printer that can eliminate the above-mentioned drawbacks of conventional printers and prevent double printing errors.

Summary of the Invention The present invention is characterized in that an operating protrusion that is pressed by a leaf spring member fixed to the machine frame is attached to the operating lever which is pivotally fixed on the armature lever with a limited swing range. , the armature lever is pressed to the standby position via the operating lever, and the relationship between the center line connecting the operating protrusion of the operating lever and the pivot shaft of the operating lever relative to the armature lever and the arrangement direction of the leaf spring member; The positional relationship is such that before the operating lever is actuated by the ratchet wheel, when the armature lever is attracted by the electromagnet and the actuating lever is moved toward the ratchet wheel, the drive lever is actuated by the ratchet wheel. The plate spring member presses the actuating protrusion so that it swings to the position where the actuating lever is actuated by the ratchet wheel.
For example, when the armature lever is moved to the operating position, the leaf spring member is configured to perform a toggle motion that presses the operating lever to a position where it cannot move into the operating range of the ratchet wheel. hand,
This prevents double printing even if the armature lever moves to the operating position immediately after printing.

With this structure, the present invention provides a printer with a simple structure and reliable operation without malfunction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory diagram showing the main parts of a printer according to the present invention. As shown in FIG. 1, there is an operating position in which the printing wheel 1 is pressed against the printing wheel 1 for printing, and a standby position in which the spring 2 is biased clockwise to separate the printing wheel 1 from the printing wheel 1 and the stopper 2a stops the operation. A printing hammer 4 is pivoted by a pivot shaft 3 so as to be able to swing between the operating position and the electromagnet 5, which is attracted to it when the electromagnet 5 is energized and swings clockwise. The armature lever 8, whose swing range is limited and is pivoted by the restraining shaft 7, and the armature lever 8, whose swing range is limited and are pivoted by the restraining shaft 7, and a standby position where the free end 8b is restrained by the support member 6 of the electromagnet 5, for example. A pivot shaft 9 is located adjacent to the free end 8b of 8.
An actuation lever 10 is pivotally fixed at its base end by an actuating lever 10 and has an engaging pawl 10b constituting an actuating end that cooperates with an actuating protrusion 10a and the printing hammer 4; A leaf spring member 11 engages with and presses the armature lever 8 to the standby position via the operating lever 10, and is rotated counterclockwise synchronously with the printing wheel 1 and engaged. A ratchet wheel 12 having a pawl 12a is formed on the armature lever 8, and a pair of limiting protrusions 8a, 8a are formed on the armature lever 8, which are spaced apart from each other. It is arranged between the pair of limiting protrusions 8a, 8a, and these limiting protrusions 8a, 8a limit the swinging movement of the operating lever 10 to an appropriate angular range.

The above-mentioned sets of printing hammer 4, operating lever 10, leaf spring member 11, armature lever 8, and electromagnet 5 are arranged in parallel as many as the number of digits to be printed by the printer.

When the printing hammer 4 and the armature lever 8 are in the standby position, a desired printing character on the continuously rotating printing wheel 1 reaches a predetermined printing position in response to a printing command signal for performing selected printing. At the right timing, the electromagnet 5 is energized and attracts the armature lever 8, causing the armature lever 8 to swing clockwise.
The engaging pawl 10 of the actuating lever 10 is moved toward the
b enters the operating range of the engaging pawl 12a of the ratchet wheel 12, and the actuating lever 10 is struck clockwise by the engaging pawl 12a, causing the engaging pawl 10b of the actuating lever 10 to close.
The driving arm 4a of the printing hammer 4 is pressed by the drive arm 4a to swing the printing hammer 4 counterclockwise, and the printing hammer 4 is brought into contact (impact) with the printing wheel 1 to perform printing.

According to the feature of the present invention, a center line x-x connecting the center of the actuating protrusion 10a of the actuating lever 10 that can swing within a predetermined angular range and the center of the pivot shaft 9 of the actuating lever 10 relative to the armature lever 8 and leaf spring member 11
The relative positional relationship with the arrangement direction of the actuating lever 1 is as follows.
0 is actuated by the engaging pawl 12a of the ratchet wheel 12, the direction in which the leaf spring member 11 presses the actuating protrusion 10a of the actuating lever 10 (arrow A) causes the actuating lever 10 to swing counterclockwise. When the armature lever 8 is attracted by the electromagnet 5 and swung clockwise, the engaging claw 10 of the operating lever 10
b is moved to a position where it can be struck by the engaging pawl 12a of the ratchet wheel 12, whereby the actuating lever 10
is swung clockwise, and the engaging claw 10b strikes the operating arm 4a of the printing hammer 4, causing the printing hammer 4 to swing counterclockwise to perform printing.
On the other hand, the engaging pawl 10b of the operating lever 10 is connected to the ratchet wheel 12.
After being actuated by the engaging pawl 12a, the actuating protrusion 10a is pressed by the leaf spring member 11 to swing the actuating lever 10 clockwise, as shown by arrow B in FIG. to hold the actuating lever 10 in the first position. As long as the operating lever 10 is in this first position, the operating lever 10 will remain within the operating range (rotation locus) of the ratchet wheel 12, no matter what rotational (swinging) position the armature lever 8 is in. It is designed so that it does not stick out. Therefore, if the operating lever 10 is in the first position, double striking will not occur even if the armature lever 8 undergoes damped vibration.

Further, each member is returned to its retracted position by the deenergization of the electromagnet 5 after the armature lever 8 is attracted, and the armature lever 8 is returned to the retracted position via the operating lever 10 by the action of the leaf spring 11. Printing hammer 4 is spring 2
When the hammer 4 returns, the operating lever 10 returns from the first position to the second position. In this case, after the actuating lever 10 is returned to the second position by the hammer 4, the armature lever 8 may undergo damped vibration, but normally this armature lever 8
Since the peak of the damped vibration occurs before the hammer 4 returns completely, the probability of double striking is actually extremely low, and there is no practical problem.

Effects of the Invention With this configuration, in the printer according to the present invention, for printing operation, the electromagnet 5 is energized by the print command signal, the armature lever 8 is actuated, and the operating lever 10 is turned into a claw. When moving toward the wheel 12, the engaging claw 10b of the operating lever 10 enters the operating range of the engaging claw 12a of the ratchet wheel 12 due to the action of the leaf spring member 11 on the operating protrusion 10a. The engagement claw 10b of the lever 10 is struck by the engagement claw 12a of the ratchet wheel 12, and the engagement claw 10b of the operating lever 10 strikes the operating arm 4a of the printing hammer 4 to swing the printing hammer 4. At this time, the operating protrusion 10a of the operating lever 10 is moved clockwise by the leaf spring member 11 as shown by arrow B in FIG. Even if the armature lever 8 is moved to the operating position during the damped vibration of the armature lever 8, the engaging pawl 10b of the operating lever 10 will not engage the ratchet wheel. It does not engage with the pawl 12a, and an excellent effect can be obtained that can reliably prevent erroneous double-hitting.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing the main parts of a printer according to the present invention. FIG. 2 is a schematic explanatory diagram showing a state in which the printer of FIG. 1 is performing a printing operation. 1... Printing wheel, 2... Spring, 4... Printing hammer, 5... Electromagnet, 8... Armature lever, 10...
... Actuation lever, 10a... Actuation protrusion, 10b...
Engagement pawl, 11...Plate spring member, 12...Rawl wheel, 1
2a... Engaging claw.

Claims (1)

[Claims] 1. A rotary printing wheel, a printing hammer that can swing between an operating position where it is pressed against the printing wheel and performs printing and a standby position that is separated from the printing wheel, and is normally held elastically in the standby position. an armature lever having a limited swing range between an operating position attracted by the energization of the electromagnet and a standby position separated from the electromagnet; an operating lever having a limited swing range between a first position and a second position and having an engaging pawl and an operating protrusion; comprising a leaf spring member that presses the armature lever to a standby position via the armature lever, and a ratchet wheel that rotates in synchronization with the printing wheel and has an engaging pawl;
When the electromagnet is energized by a print command signal, the engaging pawl of the actuating lever is actuated via the armature lever so as to come into contact with the engaging pawl of the ratchet wheel, thereby causing printing to occur via the actuating lever. A flying line printer that prints by operating a hammer to an operating position, wherein the center line connecting the operating projection of the operating lever and the pivot shaft of the operating lever relative to the armature lever and the arrangement direction of the leaf spring member The relative positional relationship is such that before the actuating lever is actuated by the ratchet wheel, the leaf spring member acts to urge the actuating lever to the second position; The leaf spring member is configured to provide a toggle motion acting to urge the actuating lever to the first position, the actuating lever being in the first position after being actuated by the vehicle. If the armature lever moves to an operating position due to damped vibration, the operating lever cannot move into the operating range of the ratchet wheel.