JPS6161982B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device using a cassette type wheel.

In conventional printing devices, a type wheel is attached to a type selection motor shaft, and many types of type wheels are prepared and applied to many types of fonts. In such conventional printing devices, it is not easy to replace the type wheel, and there is a problem in that the type wheel cannot be stored reliably.

The applicant solved this problem by converting the type wheel into a cassette. The cassette-type type wheel makes it easy to replace the type wheel, which has favorable effects in terms of storage. In the cassette type wheel, the petal type wheel is rotatably held in the cassette, and the type wheel can be replaced and removed by the simple operation of mounting the cassette in a predetermined cassette holder.

In the case of a cassette-type type wheel, the type wheel held in the cassette can be easily and reliably attached to and removed from the type selection motor, and when attached, it is required that the type wheel has good concentricity with the axis of the type selection motor and that its posture is maintained. . Furthermore, it is necessary that the printing hammer not be affected by the impact.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing device using a cassette-type wheel having a simple construction.

Embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, a petal-shaped wheel 2 is housed in a box-shaped cassette 1. As shown in FIG. 2, the petal-shaped type wheel 2 has a center plate 5 on which a large number of fingers 4 having typefaces 3 are arranged radially. The center plate 5 is provided with a boss protrusion 6.

As shown in FIG. 1, the first wall of the cassette 1 (the left wall in FIG. 1) is provided with a first opening through which a type selection motor shaft 8 serving as a driving means enters and exits. A second opening smaller than the first opening is provided in a second wall (the right wall in FIG. 1) opposite to the first wall.

An opening 7 is formed in the cassette 1 so that selected letters of the type wheel 2 are exposed at a position where the letters are struck by a type hammer (not shown). Carrying hole 1 in cassette 1
a is formed, and the boss portion 6 of the type wheel 2 is loosely fitted, that is, inserted with play.

A shaft 8 of a type selection motor is inserted into the boss portion 6 . The shaft 8 is formed with a tapered part 9 at its tip, so that the shaft 8 can be smoothly inserted into the boss part 6 even if the vertical position of the type wheel 2 is slightly shifted. When the shaft 8 is fully inserted, the minimum necessary portion of the shaft 8 is slid into the hole of the boss portion 6 in order to reduce coupling resistance.

A connecting member 10 is fixed to the shaft 8 with a pin 11 or the like. As shown in FIG. 3, the connecting member 10 is provided with a connecting piece 12 and a plurality of posture maintaining arms 13.

An engaging hole 14 is formed in the center plate 5 of the type wheel 2, and a connecting member 10 fixed to the shaft 8 is connected to the engaging hole 14 when the shaft 8 is fully inserted into the boss 6 of the type wheel 2. Piece 12 is inserted. The rotation of the shaft 8 is transmitted to the type wheel 2 by the connecting piece 12, and the type wheel 2 is reliably rotated without slipping or the like.

Holding holes 20 are formed at equal intervals on a concentric circle in the center plate 5 of the type wheel 2, and a plurality of posture holding arms 13 are arranged facing the holding holes 20. The posture holding arm 13 has a forked tip, and comes into contact with the surface of the center plate 5 of the type wheel 2 when the shaft 8 is fully inserted into the boss 6, and is used for relative positioning of the connecting member 10 and the type wheel 2, and for positioning the connecting member 10 and the type wheel 2 relative to each other. A stopper 15 that functions to maintain posture;
A retaining piece 16 that is inserted into the holding hole 20 and acts to prevent the type wheel 2 from coming off from the connecting portion 10.
constitutes. Of course, it is not a fork, but a stopper.
5 and the retaining piece 16 may be formed separately.

The retaining piece 16 is formed as an elastic piece, and has a protrusion 17 that bulges in the radial direction of the type wheel 2 at its tip. The protrusion 17 comes into contact with the edge of the retaining hole 20 when the retaining piece 16 is inserted into the retaining hole 20, and when pushed in with a predetermined force, the retaining piece 16 is flexed and retained using its elasticity. The type wheel 2 is shaped so that it can be inserted into the hole 20, and after the protrusion 17 has passed through the holding hole 20, the protrusion 17 is caught on the opposite edge of the holding hole 20, and the type wheel 2 cannot be pulled out with a slight force. Set. The opposite edge can also be made into a slope to abut against the protrusion 17.

When the shaft 8 is pulled out from the cassette 1, that is, when the retaining piece 16 is pulled out from the holding hole 20 of the type wheel 2 and the posture holding arm 13 is detached from the type wheel 2, the type wheel 2 is held in the cassette in the cassette 1. The front and back directions are regulated by a projection 18 provided on the front wall and a projection 19 provided on the inner surface of the back cover, and the device is held in a predetermined position substantially vertically.

Since the type wheel 2 is held at the home position by means not shown, the connecting piece 12 is smoothly inserted into the engagement hole 14 when the shaft 8 is inserted into the cassette 1.

With this device, when the cassette is attached to the type selection motor shaft, the type wheel can be supported by the type selection motor shaft in a free state relative to the cassette, so even when the type wheel is rotated by the type selection motor, the type wheel can be selected. Even when printed fingers are struck by a type hammer, they are held without contacting the cassette, and the type wheel can always be held stably in a plane perpendicular to the motor axis. Therefore, when the type wheel is rotated or struck, there is no adverse effect, and troubles such as breakage of type fingers can be prevented.

By making the tip of the motor shaft tapered, the connection piece of the connecting member and the posture holding arm can be smoothly engaged with the type wheel, and the shaft can be fitted into the type wheel boss part, and the center of rotation can be secured. A part of the shaft is slidably fitted to the boss.

The type wheel is held in a plane perpendicular to the motor shaft by three attitude-holding arms, as shown in the illustrated example, and the type wheel can also be positioned. Furthermore, the type wheel can be held in a state where it is prevented from coming off by the posture holding arm, and the posture can be held in a stable state.

According to the present invention, the second opening provided in the second wall opposite to the first wall of the cassette through which the shaft for driving the type wheel enters and exits supports the protrusion provided in the center plate of the type wheel. It became possible to position the inside of the cassette. Moreover, in the case of the present invention, since there is no need for a spring or the like for positioning the type wheel within the cassette, the cassette itself can be made thin, and the type wheel is provided on the protrusion of the type wheel and on the second wall of the cassette. Since there is play between the type wheel and the second opening provided in the center plate of the type wheel, there is no resistance when the shaft of the drive means is inserted into the hole provided in the center plate of the type wheel and the type wheel is rotated.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a cassette-type type wheel according to the present invention, FIG. 2 is a perspective view of the type wheel,
FIG. 3 is a perspective view of the connecting member. 1...cassette, 2...type wheel, 3...
...Print, 4...Finger, 8...Shaft, 10...
Connecting member, 12... Connecting piece, 13... Posture holding arm, 14... Locking hole, 15... Stopper, 1
6... Retaining piece, 17... Protrusion, 20... Holding hole.

Claims (1)

[Scope of Claims] 1. A printing device comprising a type wheel having a plurality of fingers having printed characters, a cassette for accommodating the type wheel, and a driving means having a shaft for rotating the type wheel, comprising: a first opening provided in the first wall of the cassette for entry and exit of the shaft of the means; and a second opening provided in the second wall opposite the first wall of the cassette and smaller than the first opening. , the type is inserted with play into a hole provided in the center plate of the type wheel for inserting the shaft of the drive means and into a second opening provided in the second wall of the cassette; and a protrusion provided on the center plate of the type wheel, and a second opening provided in the second wall of the cassette can support the protrusion provided on the center plate of the type wheel. Printing device.