JPS5852511B2 - Printing device hammer mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device, and more particularly to a hammer mechanism of a printing device.

Recently, small desktop calculators and measuring instruments have come equipped with small, lightweight printing devices, allowing them to immediately print out the displayed results on recording paper.

FIG. 1 is a block diagram of the hammer mechanism of the above-mentioned printing device. In the figure, 1 is a type wheel, and 2 is a type provided on the type wheel 1. As shown in FIG.

3 is a printing hammer, which has a hammer part 3a at the tip, a pivot part 3b at the center, and an arm part 3e at the base.

Reference numeral 4 denotes a pivot shaft that passes through the pivot portion 3b of the printing hammer 3, and pivotally connects the printing hammer 3 to a base such as a chassis.

5 is a stopper, 6 is a tension spring that biases the printing hammer 3 clockwise and presses the hammer portion 3a against the stopper 5, and 7 is a drive piece that fits into the arm portion 3c of the printing hammer 3.

8 is a recording paper. In the above mechanism, when printing on recording paper, the drive piece 7 is rapidly moved in the direction of the arrow, the printing hammer 3 is rotated counterclockwise, and the hammer portion 3a coats the recording paper with ink. The desired characters are printed on the recording paper by strongly hitting the printed characters 2.

By the way, since the printing hammer 3 of the conventional printing device as described above is of a type that is pivoted and rotated by a pin, a strong force is applied to the lower part 3a-1 of the hammer part 3a during printing operation, and the upper part 3a −2 is subject to a weaker force than this.

Therefore, the force applied to the printing surface is not averaged, resulting in uneven printing.

Further, since the distance from the pivot portion 3b to the hammer 3a is longer than the distance from the pivot portion 3b to the arm portion 3c, the movement of the drive piece 7 is amplified and appears on the hammer portion 3a, and 3a hits the printing paper 8 at high speed, producing a high-pitched printing sound.

In addition, since the printing hammer 3 is subjected to complicated bending, high processing accuracy is required, resulting in increased costs and decreased yield.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hammer mechanism for a printing device that eliminates printing unevenness in the printing device, produces low printing noise, and is inexpensive.

Next, one embodiment of the present invention will be described in detail using the drawings.

FIG. 2 is a perspective view showing the hammer mechanism part of the printing device according to the present invention, in which 11 is a base, 12 is a plunger attached to the base 11, and a voltage is applied to the coil. Then, the rod 12a protrudes in the arrow direction.

A stud 13 stands upright on the base 11 and has a bearing portion 13a at its tip.

A lever 14 is pivotally attached to the bearing portion 13a.

Inside the lever 14 is a rod 12a of the plunger 12.
A pin 12b that stands upright from above is fitted.

15 is a hammer guide made of synthetic resin, and the two rails 1
5a and 15b.

16 is a slide hammer made of synthetic resin, and two grooves 16a and 16b provided on the bottom surface are connected to rails 15a and 15b.
and is slidably retained within the hammer guide 15.

The slide hammer 16 has a cam portion 16c at the portion where the tip 14a of the lever 14 contacts, a pin 16d on the top surface, and a cam portion 16c formed on the front surface that spans the movable range in the axial direction of the type wheel 18 described below. hammer part 16e
has.

A tension spring 17 is stretched between the pin 16d and the bearing portion 13a, and the cam portion 16C is biased toward the lever 14.

Reference numeral 18 denotes a type wheel, which has type letters around it and moves in the axial direction in the direction of the arrow while rotating.

Next, the printing operation will be explained.

FIG. 2 shows a state in which the slide hammer 16 is retracted and the printing operation is stopped.

In this state, as shown in FIG. 3, there is a gap between the type wheel 18 and the hammer portion 16e of the slide hammer 16, and the recording paper 20 is inserted into this gap.

When the plunger 12 is biased from the state shown in FIGS. 2 and 3, the rod 12a protrudes in the direction of the arrow.

Therefore, the pin 12b causes the lever 14 to rotate clockwise.

When the lever 14 rotates, its tip 14a presses the slope of the cam portion 16c of the slide hammer 16, so that the slide hammer 16 is pushed toward the type ring 18 as shown in FIG. 4, and as shown in FIG. The recording paper 20 is pressed against the type wheel 18 to perform printing.

When the bias of the plunger 12 is released, the rod 12a is retracted by the action of the spring inside the plunger 12, the lever 14 is rotated counterclockwise, and the slide hammer 16 is retracted by the force of the tension spring 17. The state returns to the state shown in FIGS. 2 and 3.

As described in detail above, in the present invention, the hammer mechanism is configured to be able to slide in the diametrical direction of the type wheel, so when the hammer portion hits the type, the operating force is applied evenly to the entire surface of the type.

Therefore, the disadvantage that the operating force differs depending on the position of the conventional apparatus is eliminated, and high-quality printing becomes possible.

Furthermore, unlike the conventional apparatus which prints by striking the printing paper, the hammer part performs the printing operation by pressing, so the printing sound is much lower than that of the conventional apparatus.

In addition, since the hammer mechanism according to the present invention can be constructed from synthetic resin molding without using metal, it is much cheaper than conventional products.

In addition, by selecting the shape of the cam portion 16c, during the printing process of the slide hammer 16, the slide operation just before the hammer contacts the type wheel 18 via the paper 20 can be performed gently, and therefore the hammer 16 can be smoothly moved. The contact is soft, there is little noise, and there is little risk of damage to parts due to impact.

Further, since the hammer portion 16e of the slide hammer 16 is formed to span at least the movable range in the axial direction of the type wheel 18, stable printing within the printable range can be performed with one slide hammer 16.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the hammer mechanism of a conventional device, Fig. 2 is a perspective view showing an embodiment of the present invention, Fig. 4 is a perspective view showing the printing operation state of the slide hammer, and Fig. 3 and fifth
The figure is a side view illustrating the operation of the slide hammer. In the figure, 1 is a type wheel, 2 is a type, 3 is a printing hammer, 4 is a pivot shaft, 5 is a stopper, 6 is a tension spring, 7 is a drive piece, 8 is a printing paper, 11 is a base, 12 is a plunger, 12a is a rod, 12b is a pin, 13 is a stud, 14 is a lever 1
4a is the tip, 15 is the hammer guide, 15a and 15b
16 is a rail, 16 is a slide hammer, 16a and 16b are grooves, 16C is a cam portion, 16d is a pin, 16e is a hammer portion, 17 is a tension spring, 18 is a type ring, and 20 is a recording paper.

Claims (1)

[Claims] 1. A type ring arranged around the type type and movable in the axial direction, a hammer part formed at least over the movable range of the type ring, and a cam part formed on the back surface of the hammer part. It has a slide hammer that moves in the diametrical direction, a spring mechanism that biases the slide hammer in the direction of separating it from the type wheel, and a lever that engages with the cam portion of the slide hammer and interlocks with the plunger. A hammer mechanism for a printing device, characterized in that a lever operated by an actuating force drives a cam part to cause the hammer part to strike the type on a type wheel.