JPH0245989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printing type printer used in electronic desktop calculators and the like. However, in the static printing method in which printing is performed after the type drum is stopped, for example, printing time and carryover time are required after printing, and there is a limit to increasing the printing speed.
Also, structurally, it is necessary to have separate drive sources for moving the carrier and operating the hammer.
It was difficult to make it small and inexpensive.

The present invention has been made in an attempt to eliminate the above-mentioned drawbacks of the conventional art, and by causing the type belt to protrude using the moving force of the carrier, printing is carried out at the same time, resulting in a high printing speed.
Further, since the drive source for the carrier and the drive source for the hammer member are shared, a printer that can be made smaller and lower in price can be achieved.

Hereinafter, the present invention will be explained in detail with reference to an embodiment shown in the drawings.

1A and 1B are an overall exploded perspective view and a sectional view illustrating an embodiment of the present invention, and 1 is a type drum base having a plurality of holes 1a and made of an elastic material such as rubber on its surface. A type belt 2 is wrapped around the outer circumference of the base 1, and the type belt 2 has a type 2a and its type 2.
It has a protrusion 2b that fits into the hole 1a on the opposite side of a,
When this protrusion 2b is pressed from inside the type drum base 1, the type 2a pops out. A drum shaft 3 is fixed to the type drum base 1, rotatably supported by a carrier 4, and has a drive gear 5 fixed to the other end. 6 is the worm gear,
The thrust direction is regulated by bent portions 4a and 4b of the carrier 4, and is held by a worm gear shaft 7 that engages with the drive gear 5.

The worm gear shaft 7 is rotatably supported between side plates (not shown) and rotated at a predetermined rotational speed by a drive motor (not shown). Further, the worm gear shaft 7 has an oval-shaped cross section, and the worm gear shaft 7 has an oval-shaped cross section.
It is slidably engaged with the same oval-shaped hole provided in the. Reference numeral 8 denotes a type selection member of the type drum, which has rack-shaped teeth and can engage with the drive gear 5 when pressed toward the type drum base 1 by a solenoid (not shown). Reference numeral 9 denotes a printing cam, and cam portions 9a for pressing a hammer 10, which will be described later, are provided on the end face at predetermined pitches. 10 has an arm 10a that holds a roller 10b for pressing the back protrusion 2b of the type 2a with a printing hammer, and a pressing arm 10c that engages with the printing cam 9; a hammer shaft 11 provided on the carrier 4; is rotatably supported. 12 is a platen, and 13 is printing paper. An ink roller 15 presses against the type drum and transfers ink onto the type surface.

The carrier 4 is guided by a guide shaft (not shown) so that it can move parallel to the platen 12. 14 is a return spring that always pulls the carrier 4 in one direction.

Next, the operation of the printing mechanism of this embodiment configured as described above will be explained using FIGS. 1, 2, 3, and 4.

The worm gear shaft 7 is driven by a motor (not shown).
When the worm gear 6 rotates in the direction A, the worm gear 6, which is engaged in a bidirectional configuration, also rotates in the same direction. Since the drive gear 5 is meshed with the worm gear 6, the drive gear 5 also rotates in the direction B, and integrally rotates with the drum shaft 3.
The type drum base 1, which is fixed to the printer, also rotates in the direction B (FIG. 2 A1, FIG. 3 A).

Now, if you want to print the desired type 1a,
The type selection member 8 is advanced by a solenoid (not shown) in order to engage the teeth of a gear 5 having teeth corresponding to each type character on the type drum base 1, for example 5a, at a predetermined position. Tooth 8a and
mesh with the teeth 5a of the drive gear 5 (Fig. 2A
2).

Since rotational force is still applied to the drive gear 5, the drive gear 5 attempts to rotate using the lock teeth 8a of the type selection member 8 as a fulcrum, and as a result, the rotation center of the drive gear 5 shifts from 3 to 3D. (Figure 2B). This state is exactly the same as the rack and pinion meshing, and the pinion rolling on the rack while meshing with each other.

When the type drum 1 moves in the column direction c while rolling, the carrier 4 also moves in the column direction c. The carrier 4 is provided with a rotatably supported hammer 10.
The pressing arm 10c is engaged with the cam portion 9a of the printing cam 9. When the hammer 10 moves in the column direction c together with the carrier 4, the pressing arm 10c tries to get over the cam part 9a, rotates in the E direction, and the pressing roller 10b hits the back protrusion 2 of the type belt 2.
By pressing b, the type comes into contact with the printing paper 13 and the ink is transferred (FIG. 3B). Furthermore, the carrier 4, type drum base 1, and hammer 10 are combined into one,
Move in the girder direction c and press the hammer 10 with the pressing arm 1.
When 0c gets over the cam portion 9a of the printing cam 9, the printed characters also separate from the printing paper 13 and the printing operation ends. (Fig. 3c) Now, if the solenoid that was pressing the type selection member 8 is de-energized and the drive gear 5 is disengaged from the latch teeth 8a of the type selection member 8, the type drum 1 will start rolling motion. , and continue rotating on the spot (Fig. 2c). At this time,
Although the return spring 14 is pulling the carrier 4, it is not returned because the pressing arm 10c of the hammer 10 engages with the cam portion 9b of the printing cam 9 as shown in FIG. 3A. Similarly, if printing is performed sequentially and the printing cam 9 is moved away from the type drum 1 after printing for one line is completed, the hammer 1
The pressing arm 10c at 0 is disengaged from the cam portion 9 and returns to a predetermined position by the tension of the return spring 14. When printing one line, the printed value is 1, 2,
In the case of continuous printing such as 3, 4, . . . , the printing and movement of the printing type selection member 8 are performed in sequence by extruding once, and high-speed printing is possible. In addition, the printing pitch (digit spacing) is based on the tooth module of the drive gear 5.
Then, it becomes mπ. Also, the rack pitch of the type selection member 8 and the cam pitch of the printing cam 9 are also adjusted in the same manner.
It becomes mπ. Figure 4 B1, B2, B3 are Figure 3 B
FIG.

FIG. 5 shows another embodiment of the present invention, in which a worm gear is arranged over the entire width of the drum movement.
The above-mentioned mechanism performs printing and carrying within the time it takes to move between characters, so it is effective when the load on the motor is large and it is desired to reduce the load on the motor.

FIG. 6 shows still another embodiment of the present invention, in which a printing paper 13 is pressed against a type drum 101 by a platen hammer 112. In this case as well, the hammer must be pressed at a time when the type drum is rolling. All other mechanisms are the same as in the first embodiment.

From the above description, it is clear that according to the present invention, the following excellent effects can be obtained.

1 Since the digit time and printing time are almost the same,
A printer with high printing speed is possible.

2. Since the drive source for the carrier and the drive source for the hammer member are shared, it is possible to create a printer that is simple in structure and inexpensive and compact.

[Brief explanation of drawings]

Figures 1A and B are a perspective view of an example of the present invention and a sectional view of the type drum section, Figures 2A1, A2, B, and C
are schematic diagrams showing character selection and digit operation, Figures 3 A to C
4 is a schematic diagram showing the printing operation, FIGS. 4B1 to B3 are schematic diagrams showing the movement of the type portion, FIG. 5 is a diagram of another embodiment, and FIG. 6 is a diagram of still another embodiment. 1... type drum, 10... hammer, 15...
...Ink roller.

Claims (1)

[Scope of Claims] 1. A type drum having a type belt wrapped around a cylindrical drum base provided with a plurality of holes around the periphery, the type belt having a protrusion on the back surface that fits into the holes, and the type drum mounted thereon. a carrier that moves in the width direction of the printing paper; and a plurality of protrusions arranged corresponding to the printing pitch and having a vertical surface at one end and an inclined surface at the other end, the carrier moves along the direction of movement of the carrier. a cam member provided on the carrier, one end of which can come into contact with a protrusion of the type belt, and the other end movable along a protrusion of the cam member in accordance with movement of the carrier; a hammer having a substantially V-shape; and as the other end of the hammer moves over the convex portion of the cam member along the inclined surface in response to the movement of the carrier, the one end of the hammer touches the letter type. A printer characterized in that printing is performed by pressing a protrusion of a belt, and after printing, the other end of the hammer engages with the vertical surface to prevent the carrier from returning.