JP2708020B2 - Ribbon cassette attachment / detachment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon cassette attaching / detaching mechanism in a printer.

[0002]

2. Description of the Related Art Conventionally, a ribbon cassette attaching / detaching mechanism is shown in FIG.
As shown in (a), an engagement hook 3A is formed on the carrier frame 3, and the engagement hook 3A and the engagement pin 71 of the ribbon cassette 70 are engaged.

[0003]

As shown in FIGS. 6B to 6D, when the ribbon cassette 70 is removed, the ribbon cassette 70 is rotated clockwise around the engaging pin 71 of the ribbon cassette, and then rotated. After moving the ribbon cassette 70 to the left, pull it upward to remove it. However, when the engagement pin is not disengaged from the engagement hook on the carrier frame, if the ribbon cassette 70 is forcibly raised or the ribbon cassette is further rotated rightward from the state shown in FIG. There is a problem that the engagement hook is broken.

An object of the present invention is to provide a ribbon cassette attaching / detaching mechanism which does not cause a risk of breakage of an engaging pin or an engaging hook when removing a ribbon cassette.

[0005]

According to the present invention, there is provided a ribbon frame including an engaging pin for fixing a ribbon cassette to a carrier frame and a carrier frame having an engaging hook for engaging the engaging pin. When the cassette is lifted and removed by a certain angle, a ribbon cassette attaching / detaching mechanism having a projection having an inclined surface that comes into contact with the rear end of the ribbon cassette and keeps the engaging pin away from the engaging hook is obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing a first embodiment of an ink ribbon cassette attaching / detaching mechanism according to the present invention. In the figure,
The platen 1 faces the print head 2 across the recording paper. The print head 2 has an ink ribbon and prints on recording paper on a platen by the impact force of a wire in the head. The print head 2 is a carrier frame 3
It is fixed to. The carrier frame 3 is supported by structural members of the guide shaft 4 and the main stay 5, and is slidable in the length direction of the guide shaft 4 by the timing belt 6. A ribbon cassette 7 is detachably mounted on the carrier frame 3. A pair of projecting pieces 7A are formed at the rear end of the ribbon cassette 7 on the side of the main stay 5, and an engaging pin 7B parallel to the main stay 5 is formed at the tip of the projecting piece 7A. The tip curved surface 7C of the protruding piece 7A is a circumferential surface having a predetermined diameter.

FIG. 2 is an enlarged side view of an engagement portion between the ribbon cassette 7 and the carrier frame 3. A pair of engaging hooks 3A are formed integrally with the carrier frame 3 at portions corresponding to the engaging pins 7B in the carrier frame 3, and hook the engaging pins 7B. An inclined projection 3B is formed integrally with the engaging hook 3 on the outer surface of the engaging hook 3A and at a portion facing the distal end curved surface 7C of the protruding piece 7A. The inclined projection 3B has an inclined engagement pin 7B.
And the hook 3B is formed so as to fall as it approaches the engagement portion with the engagement hook 3B.

Next, the operation for removing the ribbon cassette 7 will be described with reference to FIGS. 3 (a) to 3 (c) and FIGS. 4 (a) to 4 (a).
This will be described with reference to FIG. FIG. 3A is a side view when the ribbon cassette 7 is completely mounted on the carrier frame 3, and FIG. 4A is a side view showing a part of FIG. 3A. In this state, when the ribbon cassette 7 is lifted from the platen head 2 side, the ribbon cassette 7 rotates about the engaging pin 7B and becomes a state shown in FIG. When the ribbon cassette 7 is further lifted, the state shown in FIGS. 4B and 4C is reached. Curved surface 7
C slides and the engagement pin 7B moves. Here, since the inclined surface of the inclined projection 3B is formed so as to fall as it approaches the engaging portion between the engaging pin 7B and the engaging hook 3A, the tip curved surface 7C slides smoothly along the inclined surface. ,
The engagement pin 7B naturally comes off the engagement hook 3A. When the ribbon cassette 7 is perpendicular to the carrier frame 3 as shown in FIG.
Completely out of A. FIG. 3 (c) shows a state in which it has come off.

As described above, just by rotating the ribbon cassette 7, the engaging pin 7B is naturally released from the engaging hook 3A, and when the ribbon cassette 7 is rotated by 90 degrees or more, the engaging pin 7B has already been rotated. Is disengaged from the engagement hook 3A, so that no excessive force is applied to the engagement pin and the engagement hook, and there is no fear of breakage.

FIG. 5 is a perspective view showing a second embodiment of the present invention. In FIG. 1, the engagement hook 3A is in the engagement state with the protruding piece 7A at the time of engagement.
In the second embodiment, the engaging hook 3A is arranged outside the protruding piece 7A '. The engaging pin 7B 'hooked on the engaging hook 3A is
It protrudes outside A '. In addition, the inclined projection 3B '
It is on the side opposite to the position of the inclined projection 3B in FIG. This embodiment also provides the same effects as the first embodiment.

The present invention is not limited to the embodiment described above. For example, a cylindrical projection may be used instead of the inclined projection. In this case, the protrusion is
If the ribbon cassette has a surface (a cylindrical surface in the case of a cylindrical projection) which is inclined toward the engagement pin engaged with the engagement hook, the rear end portion of the ribbon cassette may extend along the inclined surface. Slip and the engaging pin can be removed smoothly. In addition, protrusions such as inclined protrusions and cylindrical protrusions may be directly fixed on the carrier frame 3 instead of being provided on the engagement hooks.

[0013]

As described above, the ribbon cassette attaching / detaching mechanism according to the present invention has an effect of preventing the carrier frame from being broken and easily removing the ribbon cassette by forming a projection having an inclined surface.

[Brief description of the drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is an enlarged side view showing an engagement portion of the ribbon cassette attaching / detaching mechanism shown in FIG.

FIG. 3 is a side view showing an operation flow of the first embodiment of the present invention.

FIG. 4 is a side view showing a partially enlarged flow of the operation in FIG. 3;

FIG. 5 is a perspective view showing a second embodiment of the present invention.

FIG. 6 is a side view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen 2 Print head 3 Carrier frame 3A Engagement hook 3B Inclined protrusion 4 Guide shaft 5 Main stay 6 Timing belt 7 Ribbon cassette 7A Engagement pin

Claims (5)

(57) [Claims] 1. A ribbon cassette attachment / detachment mechanism including an engaging pin for fixing a ribbon cassette to a carrier frame and a carrier frame having an engaging hook for engaging the engaging pin, A ribbon cassette having a projection having an inclined surface that comes into contact with the rear end of the ribbon cassette and lifts the engagement pin away from the engagement hook when the ribbon cassette is lifted and removed at a predetermined angle around the engagement pin. mechanism. 2. The ribbon cassette according to claim 1, wherein the projection is an inclined projection having a surface which is inclined toward the engagement pin engaged with the engagement hook. mechanism. 3. The ribbon cassette attaching / detaching mechanism according to claim 1, wherein the projection is a cylindrical projection. 4. The ribbon cassette attaching / detaching mechanism according to claim 1, wherein the projection is formed integrally with the engaging hook. 5. The ribbon cassette attachment / detachment mechanism according to claim 1, wherein a surface of the rear end of the ribbon cassette that contacts the protrusion is a curved surface.