JPS5924520Y2 - Printer type wheel mounting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a type wheel mounting device for a printer, which has a fixing means for removably fixing the type wheel to a rotating shaft, and a type wheel gripping means.

A type wheel mounting device of the type described above is well known, which allows the type wheel to be removed from the rotating shaft when replacing or repairing the type wheel.

This type of type wheel attachment device allows the operator to attach and detach the wheel to the rotating shaft by pinching the gripping means, but in order to improve the workability during this attachment and detachment work, it is necessary to make the gripping means easier to grip. In this sense, it is desirable to configure the grip means to be large.

On the other hand, however, since the type wheel is set in a narrow space, if the gripping means is configured to be large, it may interfere with other machine elements.In this sense, it is desirable to configure the gripping means to be as small as possible. preferable.

As described above, the grip means has the difficulty of satisfying two contradictory requirements.

Conventionally, in order to deal with this, the grip means is composed of two members: a base fixed to the type wheel and a movable grip fitted movably with respect to the base. The entire reading means is housed compactly by bringing the base and the knob close to each other, and the knob is moved in a direction away from the base when the type wheel is attached or removed, so that the knob can be easily grasped.

However, with this configuration, the grip means must be composed of two members, the base and the grip, and the grip must be constructed so that it does not separate from the base, making the structure of the grip complicated. Not only that, but it also had the disadvantage of being extremely difficult to manufacture.

The present invention aims to provide a type wheel mounting device for a printer that eliminates the above-mentioned conventional drawbacks, and embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a type wheel 2 is mounted on a rotary shaft 1 which is rotationally driven by a motor (not shown) by a mounting device according to the present invention.

The type wheel 2 includes a central boss portion 3 and a number of fingers 4 extending radially from the boss portion, and a type 5 is provided at the tip of each finger 4, as shown in particular in FIG.

The boss portion 3 is provided with a center hole 6 into which the rotating shaft 1 is inserted.

The type wheel mounting device according to the present invention includes a type wheel 2
fixing means 7 for removably fixing the to the rotating shaft 1;
The fixing means 7 in this example includes a receiving plate 9 fixed to the rotating shaft 1 and a clamp plate 1 fixed to the boss portion 3 of the type wheel 2.
It is composed of 0 and 0.

In this case, in the state shown in FIG. 1 in which the cylindrical part 11 protruding from the center of the clamp plate 10 is fitted into the central hole 6 of the boss part 3, and the wheel 2 is attached to the rotating shaft 1. The tip of the rotating shaft 1 is a cylindrical portion 11 of the clamp plate.
is mated to.

Further, the clamp plate 10 is provided with tongue pieces 12 that are opposed to each other in the diametrical direction thereof, and each of these tongue pieces has a locking protrusion 1.
3 is installed protrudingly.

The clamp plate 10 is made of plastic, for example, and its tongue piece 12 is elastically deformable.

As shown in FIG.
is attached to the edge of the

As a result, the type wheel 2 is prevented from moving in the axial direction with respect to the rotary shaft 1, and relative rotation between the type wheel 2 and the rotary shaft 1 is also prevented.

On the other hand, the grip means 8 in this example includes a ring-shaped base 15 and a grip portion 16, and these base portions and the grip portion are integrally connected to each other by two columnar connecting portions 17. (See also Figures 3 to 5).

The base portion 15 is fixed concentrically to the boss portion 3 of the type wheel 2.

The gripping means 8 as described above is made of an elastic material, such as plastic, in particular polypropylene, or a leaf spring material, and the gripping portion 16 can be gripped with the fingers and released from the base 15 as shown in chain lines in FIG. It is designed so that it can be bent in the direction of separation, and when the finger is released, it automatically returns to a state substantially parallel to the base 15, as shown by the solid line in FIG.

In this case, in order to improve the flexibility of the knob portion 16,
It is desirable to form the knob part 16 into a ring shape and to reduce its thickness, and to form a constriction 18 in the inclined columnar connecting part 17.

Further, as shown in the figure, if an inverted trapezoidal projection 19 is provided on the constricted portion 18, the knob 16 can be quickly returned to the solid line state when the finger is released from the knob 16, which is advantageous. be.

20 shown in FIG. 1 is the platen of the printer,
During normal printing operation, the printing paper (
Printing is carried out by striking the type 5 of the rotating wheel 2 with a hammer (not shown) placed behind the type 5.

During such a printing operation, the type wheel 2 is located in a narrow space, and various components 20, 21 of the printer are located near the gripping means 8. It is small and compact so as not to interfere with 20 and 21, and the distance between the knob part 16 and the base part 15 is also set small.

Therefore, there is no problem that the gripping means 8 interferes with each element of the printer.

To remove the type wheel 2 from the rotary shaft 1, the rotation of the type wheel 2 is stopped, and the grip portion 16 of the grip means 8 is grasped with fingers and flexed as shown by the chain line in FIG.

In this case, various elements 20 and 21 are located near the knob 16.
is located, and the operator has to put his/her fingers into a narrow space. However, since the grip portion 16 is formed as described above, the operator can grasp the grip portion 16 without any trouble.

That is, since the knob portion 16 is formed in a ring shape, a fingernail can be easily hung on the ring, and the ring-shaped knob portion 16 can be easily bent.

Next, if you pull this knob 16 to the right in FIG.
The locking protrusion 13 of the clamp plate 10 is disengaged from the edge of the locking hole 14 of the receiving plate 9, the tongue piece 12 is disengaged from the locking hole 14, and the type wheel 2 is easily separated from the rotating shaft 1.

In this case, the grip portion 16 can be bent in the direction away from the base portion 15 and the pulling operation can be performed by pinching it, so this operation can be easily performed despite the small size of the grip means 8. can.

That is, the gripping means is small when the printer is driven, and its operability is extremely good during the operation of pulling out the wheel, so that the two conflicting demands for the gripping means can be reliably satisfied.

Moreover, according to the above configuration, since the grip means is integrally formed, it is easy to manufacture and the cost can be kept low, and the work of assembling the grip means with the type holes, wheels, etc. is also easy. be.

Of course, in order to attach the type wheel to the rotating shaft, it is only necessary to perform the operation in reverse to the above operation, and after this attachment is completed, if you release your finger from the knob 16, the knob 16 will be as shown in Fig. 1. Since it automatically and quickly returns to the state shown, and the grip means 8 is kept small, interference of the grip means with other elements when the printer is driven is prevented.

In addition, when attaching and detaching the wheel, the wheel 2 and rotating shaft 1
It would be advantageous if the wheels could be tilted (such tilted wheels are schematically shown in dashed lines in FIG. 1), since this would make the operation of attaching and detaching the wheels easier.

As is clear from FIG. 4, the connecting part 17 and the knob part 16 are connected at the root position so that the pinched part (dashed line) can be gently connected to the connecting part 17. is formatted.

Here, for reference, a configuration example of a conventional knob means will be briefly described.

FIGS. 6 and 7 show an example of a conventional gripping means, and this gripping means 8a includes a base 15a fixed to a boss portion 3a of a type wheel 2a, and a movable gripping portion fitted to this base 15a. It consists of two parts: 16a.

In this case, a collar 22 is provided at the tip of the cylindrical portion of the base 15a.
A protruding portion 22a is provided, and normally (when driving the printer, etc.), this flange 22a is engaged with the first stepped portion 23a of the knob portion 16a.

At this time, the distance between the base portion 15a and the knob portion 16a is W.

When removing the type wheel 2a, press the knob 16a
By pulling the button to the right, the collar 22a can be attached to the knob 16.
The second stepped portion 24a of a engages with the second step portion a, thereby increasing the distance between the base and the knob portion to a size of W+C.

In this way, the gripping means 8a can normally be accommodated in a small space (the spacing is W), and when the wheel is being pulled out, the gripping member 16a is kept relatively far away from the base 15a, making it easier to pull out the type wheel.

However, with this configuration, it is structurally difficult to increase the distance C that separates the knob 16a from the base 15a, and moreover, it is difficult to increase the distance C that separates the knob 16a from the base 15a. Part 16a
It is necessary to provide an ear 25a on the base, but it is not easy to form this ear 25a because the structure is small, and when fitting the ear 25a to the base when manufacturing the printer, There is also a risk of damage.

On the other hand, in the configuration according to the present invention described above, the knob part 16 is bent and separated from the base part 15, so it is possible to separate the bent knob part 16 and the base part by a large distance. Moreover, since the grip means can be formed integrally, there is no difficulty in assembling unlike the conventional grip means.

Although the preferred embodiment of the present invention and an example of the conventional configuration have been described above, the present invention is not limited to this embodiment and can be modified in various ways.

For example, the fixing means 7 can be constituted by various suitable means that are conventionally known or proposed, and the drawings merely show one specific example thereof.

It goes without saying that the present invention can also be applied to a mounting device for type wheels other than those shown, for example, type wheels shaped like balls or teacups.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view of a printer to which the present invention is applied, Fig. 2 is an exploded perspective view of the fixing means, type wheel, and gripping means, Fig. 3 is a front view of the gripping means, and Fig. 4 is the third
FIG. 5 is a cross-sectional view taken along the line IV-IV in FIG. 3, FIG. 6 and FIG. 7 are cross-sectional views showing an example of a conventional knob means. 1...Rotating shaft, 2...Type wheel,
7...Fixing means, 8...Knob means,
15...base, 16...knob part.

Claims (1)

[Scope of utility model registration request] A type wheel mounting device for a printer comprising a fixing means for removably fixing a type wheel to a rotating shaft, and a type wheel gripping means, wherein the gripping means includes a base portion fixed to the type wheel, and a base portion thereof. a connecting portion protruding from the connecting portion; a knob portion fixed to the connecting portion and extending so as to spread from the connecting portion; a constriction formed as a recess at a fixed position between the knob portion and the connecting portion; a protruding part that protrudes from the part and is located in the constricted part thereof and forms a space between the part and the knob part; 1. A type wheel attachment device, characterized in that the knob portion can come into contact with the protruding portion when the type wheel is pinched.