JPS595572Y2 - printing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a small printer using an ink roll.

Conventionally, as a printing mechanism using a type wheel selection method that selects a rotatable type wheel independently for each digit and prints, a ratchet wheel with teeth that corresponds one-to-one with the type on the type wheel has been used. Some use rotary clutches.

An example of a printing apparatus using an ink roll utilizing this method is shown in FIG. 1 and will be described. However, this method has disadvantages such as a large type wheel or restrictions on the size of the type.

In this method, the driving shaft 1 and ratchet wheel 2 are
When the ratchet wheel 2 rotates in the direction and the tooth of the ratchet wheel 2 corresponding to the selected character comes under the ratchet pawl member 3, the electromagnet 4 is activated.

Thereby, the trigger lever 5 is rotated, the ratchet pawl member 3 and the ratchet wheel 2 are engaged, and the type ring 6 to which the ratchet pawl member 3 is fixed is rotated to perform selection.

When all the digits of the type to be printed are rotated at a position facing the ink roll 7, the ink roll 7 is moved in the direction of arrow B to apply ink, and the rotated type to be printed is placed on the printing member. 8, the printing member 8 is moved in the direction of arrow C to print on the paper 9.

After printing, the driving shaft 1 rotates one more rotation, and the ratchet pawl member 3 returns to its original state due to the trigger lever 5 returning to the reset state, and both the type wheel 6 and the driving shaft 1 return to the reset state.

As you can see from the above example, in this method, the driving shaft rotates twice,
Since one rotation of the type wheel forms one cycle, it is not possible to place type on the circumference of the type wheel located between the ink application position and the printing position, compared to when using ink ribbon, pressure-sensitive paper, etc. The disadvantage was that the outer shape of the type wheel became larger.

On the other hand, if type wheels with the same external shape are used, it is necessary to make the type smaller or to reduce the number of types, which poses a big problem in terms of quality and functionality.

The purpose of the present invention is to arrange a large number of printed characters without increasing the diameter of the printing wheel by arranging the printed characters all around the printing wheel.

Another object of the present invention is to obtain clear print quality by transferring ink immediately before printing selected type characters.

An embodiment of the present invention will be explained with reference to FIG. 2. Numeral 10 is a driving shaft that rotates approximately twice and a predetermined angle (α) in one printing cycle, and numeral 11 is supported by the driving shaft 10 and has a plurality of printed characters on its outer periphery. 12 is a ratchet wheel fixed to the driving shaft 10, and 13 is attached to the type wheel 11 and engaged with the ratchet wheel 12 by a spring 14. Ratchet pawl member, 15
16 is an electromagnet that rotates the selection return member 15; 17 is a pressing member; and 17 is a driving member. The ink roll 19 is pressed against the type wheel 11 by the movement of the cam 1B which rotates in synchronization with the rotation of the shaft 10.

Reference numeral 20 denotes a printing member, which presses paper 21 against the type by a mechanism not shown when the type to be printed comes to an opposing position.

In the above configuration, first, the driving shaft 10 and the ratchet wheel 12 start rotating in the direction of the arrow.

When the tooth to be selected on the ratchet wheel 12 comes under the ratchet pawl member 13, the electromagnet 16 is activated, the selection return member 15 is removed from the ratchet pawl member 13, and the spring 14 is removed.
The ratchet pawl member 13 is engaged with the ratchet wheel 12 by the force of .

If the same selection is made for all digits, when the driving shaft 10 rotates once, the characters to be printed will be aligned in a straight line in the digit direction at a position facing the ink roll 19.

At this time, the ink roll 19 is pressed against the type by the cam 18 and ink is applied to the type.

Further, the driving shaft 10 is rotated by a predetermined angle (α), and the type letters to be printed on the type wheel 11 are rotated to a position facing the printing means 20.

At this time, the printed characters located between the ink application position and the printing position are rotated by 1+α.

At this time, if the selection return member 15 that has selected at least the type between the ink application position and the printing position is held by the electromagnet 16 and positioned outside the rotational trajectory of the ratchet pawl member 13, the ink application position and the print The type wheel 11 which has selected the type between the positions does not return to the standby position.

When the type to be printed comes to a position facing the printing means 20 as described above, the printing member 20 is operated by a mechanism not shown, and the paper 21 is pressed against the type to perform printing.

After printing, if all the selection return members 15 are returned to the reset state and the driving shaft 10 is rotated approximately one revolution, all the selection return members 15 have been reset, so the ratchet pawl member 13
The ratchet wheels 12 are disengaged, and all the type wheels 11 stop at the standby position.

As explained above, according to the present invention, even if the type is arranged around the entire circumference of the type wheel and the type arranged between the ink roll and the printing member is selected, the selected type is Since the ink can be transferred, printing can be performed before the ink dries, and clear print quality can be obtained.

Furthermore, since the type letters can be arranged around the entire circumference of the type ring, many types can be arranged without increasing the outer diameter of the type ring, and the size of the type ring can be reduced.

The following effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a conventional example. FIG. 2 is a side sectional view showing an embodiment of the present invention. 10 is a driving shaft, 11 is a type shaft, 12 is a ratchet wheel, 13 is a ratchet claw member, 15 is a selection return member, 1
9 is an ink roll, 20 is a printing means, and 21 is paper.

Claims (1)

[Scope of Claim for Utility Model Registration] A type wheel selection type printing device using an ink roll, comprising a type wheel having type characters around the entire circumference and rotatable independently for each digit, and teeth corresponding to the type type. a ratchet wheel having a drive shaft that rotates by 1+α during a type selection stroke and approximately one revolution during a return stroke to return the type wheel to a standby position; a ratchet pawl member provided on the type wheel so as to engage with the teeth and rotate the type wheel synchronously with the driving shaft to place the desired type at a printing position; a selective return member that selectively engages and detaches from the teeth; an ink roll swinging means that brings an ink roll into contact with the type wheel just before the selected type is aligned at the printing position; an ink roll that transfers the characters all at once; a printing member that prints the letters aligned at the printing position; and selectively controlling the selective return member so that the ratchet pawl member engages with or disengages from the teeth. and an electromagnet that holds the selection return member outside the rotational trajectory of the ratchet pawl member until the end of the selection process at least when the type characters arranged between the ink roll and the printing member are selected; A printing device comprising: