JPH022433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a printing device such as a typewriter having a cylindrical platen.

Conventional configurations and their problems In recent years, many printing devices have appeared that perform printing while maintaining an appropriate distance from a platen wrapped with printing paper and moving laterally relative to a carriage on which a printing mechanism is mounted. . These printing devices tend to be smaller and lighter, and the paper holder in particular is an obstacle to miniaturization because it is impossible to reduce the width of the paper.

A conventional printing device will be described below with reference to the drawings. FIG. 1 is a sectional view of the main parts of the platen part of a conventional printing device, in which 1 is a platen, 2 and 3 are platen shafts, 4 and 5 are bearings, 6 is a machine frame,
Reference numeral 7 denotes an operating lever of a paper holding mechanism (not shown), which pivotally connects the platen shafts 2 and 3 to bearings 4 and 5, and locks them to the machine frame 6. An operating lever 7 of a paper holding mechanism (not shown) is provided on the outside of a bearing 5 on the platen shaft 3, and is operated when holding and releasing printing paper wound around the platen 1. Further, a platen rotation mechanism (not shown) is attached to the rightmost end of the platen shaft 3, and after printing is performed by a carriage on which a printing mechanism (not shown) is mounted, the platen 1 is rotated as necessary to perform a paper feeding operation. Let's do it.

The conventional printing device is configured and operates as described above. However, in the above configuration, the maximum allowable width of the printing paper and the width dimension A of the platen 1 are equal, and the width dimensions of the bearings 4 and 5, the operating lever 7, and the platen rotation mechanism are added to this, i.e. Width on bearing 4 side Y ₁ , width on bearing 5 side Y ₂
is added, and the total width of the printing device (H=A+Y ₁ +Y ₂ )
The problem is that it cannot be made smaller.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a printing device with a reduced overall width.

Structure of the Invention The printing device of the present invention includes a platen, and a cylindrical paper special portion whose rotation center is the same as that of the platen and substantially equal to the outer diameter of the platen, adjacent to the platen in the longitudinal direction. The platen width is made smaller than the paper width, thereby realizing a narrow printing device.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a partially cutaway perspective view of a printing device according to an embodiment of the present invention. In FIG. 2, reference numeral 8 indicates a protrusion 8 that controls the operation of the paper pressing mechanism, which will be described later.
b, and is an actuating lever provided with a cylindrical sheet-accepting portion 8a having the same diameter as the outside diameter of the platen 1 adjacent to the longitudinal extension of the platen 1, 9 is a paper presser roller, and 10 is an actuator lever that clamps the paper presser roller. The pair of holders 11 are a pair of support levers that lock a shaft 12 to which the holder 10 is pivotally attached.

FIG. 3 is a partially cutaway perspective view showing the machine frame 6 and the support lever 11.

The support lever 11 is fitted into the slit hole 6a of the machine frame 6, and is connected to the spring hook part 6b of the machine frame 6 and the support lever 1.
A spring 13 stretched over the spring hook 11a of 1 biases the spring 13 vertically upward. Reference numeral 14 designates a lever fixed to a shaft 15 which is pivotally connected to a bearing portion 6c of the machine frame 6, and reference numeral 16 designates a paper guide provided with engaging portions 16a that engage with both ends 12a of the shaft 12.

FIG. 4 is a sectional view of a main part of the embodiment shown in FIG. 2.

Note that 1 is a platen, 2 and 3 are platen shafts, 4 and 5 are bearings, and 6 is a machine frame, which are the same as those of the conventional example.

The operation of the printing apparatus of this embodiment configured as described above will be described below. First, printing paper is inserted through the insertion portion 16b of the paper guide 16 and wound around the platen 1. At this time, if the printing paper is twisted and wound, when the operating lever 8 is rotated in the direction of arrow C, the lever 14 is pushed by the protrusion 8b of the operating lever 8 and rotates in the direction of arrow D. The lever 14 that was holding down the support lever 11 from rotating upward also rotates in the direction of arrow D against the biasing force of the spring 13, and the paper pressing roller 9 is moved vertically downward via the support lever 11 and the holder 10. be pushed down. In this state, the print paper that was held between the platen 1 and the paper pressing roller 9 is released, so that the distortion of the print paper can be freely corrected.

After correcting the printing paper, move the operating lever 8 in the direction of arrow C.
The paper pressing roller 9 presses the printing paper against the platen 1 in the opposite direction.

Generally, the printable width is somewhat smaller than the width of printing paper. Therefore, the maximum width of the printing paper is A, but there is no practical problem even if the width of the platen 1, which receives the impact force due to printing, is reduced to B by the width of the paper allowance portion 8a of the operating lever 8. That is, the width Y ₁ on the bearing 4 side is the same as the conventional one, but the width y ₂ on the bearing 5 side can be made smaller than the conventional width Y ₂ . Therefore, it is possible to make the width h (h=A+Y ₁ +y ₂ ) of the printing device smaller than the conventional width H.

As described above, according to this embodiment, a part of the operating lever of the paper holding mechanism is made equal to the outer diameter of the platen to provide a space for wrapping the edge of the printing paper,
By setting the length B of the platen to the maximum printing width (B<A), it is possible to maintain the same printing width as the conventional printing without any problem in printing, and it is possible to reduce the total width of the printing device. Furthermore, since the length of the platen is smaller than before, the weight of the elastic part, which is heavy, is reduced, and the weight of the printing device can also be reduced.

In this embodiment, the operating lever is used to operate the paper holding mechanism, but the operating lever may be a lever for switching the paper feed amount, for example, as long as it is a lever that rotates.

Further, the operating lever of the paper holding mechanism and the paper feed amount switching lever may be arranged on the right and left sides of the platen, respectively.

Effects of the Invention The present invention includes a rotary lever having a cylindrical paper-accepting portion whose rotation center is equal to that of the platen and is approximately equal to the outer diameter of the platen. An excellent effect can be obtained in that the device itself can be made smaller. Furthermore, since the paper-accepting portion of the rotary lever is adjacent to the platen, there is an effect that it also serves as a cover for the side end surface of the platen in terms of appearance.

Further, by configuring the outer circumferential surface of the bearing of the platen shaft as the shaft member of the rotary lever, the rotary operation of the rotary lever can be realized smoothly and at low cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a conventional printing device, FIG. 2 is a partially cutaway perspective view of a printing device according to an embodiment of the present invention, and FIG. 3 shows some of the components of FIG. FIG. 4 is a perspective view of the main part of the notch, and FIG. 4 is a sectional view of the main part of the embodiment shown in FIG. 1... platen, 2, 3... platen shaft, 4,
5... Bearing, 6... Machine frame, 7, 8... Operating lever, 9... Paper press roller, 10... Holder, 11
... Support lever, 12 ... Shaft, 13 ... Spring, 1
4...Lever, 15...Shaft, 16...Paper guide.

Claims (1)

[Scope of Claims] 1. A platen that is rotatably supported by a bearing member provided on a machine frame, and a cylindrical sheet of paper that is rotatable using the outer peripheral surface of the bearing member as a bearing portion and that is approximately equal in outer diameter to the platen. a rotary lever in which a permitting portion is provided adjacently on an extension of the platen in the longitudinal direction;
A printing device characterized in that the rotary lever is configured to be rotatable coaxially with and independently of the platen. 2. The printing device according to claim 1, wherein the rotating lever is a paper presser mechanism operating lever having a protrusion that operates the paper presser mechanism.