JPH0219792B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a paper feeding device such as a typewriter.

(b) Prior Art Typewriters are provided with a paper feeding device as shown in FIGS. 1 and 2 so that the next printing line is automatically moved to when one line of printing is completed. That is, 1
is a clutch mechanism provided on a rotating shaft 3 on which a platen 2 is supported, which includes a regulation plate 4 integrally fixed to the rotating shaft 3, a rotating body 5 rotatably attached to the rotating shaft 3, and a rotating body. 5, and an arm 6 protruding downward from the rotating shaft 3.
A coil spring 8, one end of which is engaged with the starting member 7, is wound between the rotating body 5 and the starting member 7 to form a well-known spring clutch. Springs 10, 10 and balls 11, 1 are placed in the recesses 9, 9 formed in the plate 4.
1 is provided, and the balls 11, 11 are pressed into the ball fitting groove 12 of the rotating body 5, thereby forming a well-known ball clutch. Reference numeral 13 denotes a plunger which is driven by the operation of a return key when one line of printing is completed, and is engaged with the arm 6 of the starting member 7, and the driving of the plunger 13 causes the starting member 7 to rotate counterclockwise.

Therefore, after printing one line, the plunger 13
is driven and the arm 6 of the starting member 7 is moved, the starting member 7 is rotated counterclockwise, and the rotation of the starting member 7 is transmitted to the rotating body 5 by tightening the coil spring 8, which further tightens the ball clutch. By being transmitted to the regulation plate 4 via the regulation plate 4
is rotated, and the platen 2 is rotated by one line of paper feed.

Therefore, in such a conventional paper feeding device,
If the load due to the moment of inertia of the platen is large, the spring clutch and ball clutch will slip, making it impossible to feed the paper stably. Also, it will take a lot of man-hours to assemble the spring clutch and ball clutch, and it will be necessary to manually move the platen. If an attempt was made to rotate the ball in the opposite direction, it would be necessary to rotate the ball clutch against the ball clutch, making the operation difficult.

(c) Object of the Invention The present invention solves the above-mentioned problems and provides a paper feeding device that is configured to perform stable paper feeding and to allow easy manual operation.

(d) Structure of the Invention In the present invention, the platen is configured to be rotated by a ratchet mechanism, and the ratchet mechanism is configured to engage with the platen only when feeding paper.

(e) Embodiments Examples of the present invention will be described below with reference to FIGS. 3 to 5. Reference numeral 14 denotes a moderation gear that is integrally fixed to the rotating shaft 3 of the platen 2, and is engaged with a plate spring 15 disposed on the side, thereby imparting moderation to the rotation of the platen 2. 16 is the rotating shaft 3 of the platen 2 as well.
The ratchet gear that constitutes the ratchet mechanism is integrally fixed to the ratchet and is formed in a sawtooth shape. 17
is an L-shaped rotating lever that is rotatably attached to the rotating shaft 3 of the platen 2, and the support shaft 18 installed in the corner
Although a clockwise rotational force is applied by a spring 20 installed between the base plate 19 of the main body and the base plate 19 of the main body, rotation is restricted by a stopper 21. Reference numeral 22 denotes an arm member rotatably mounted on the support shaft 18 of the rotary lever 17. A feed claw 23 is formed at one end to be engaged with the ratchet gear 16, and the other end is engaged with the plunger 13. Although a clockwise rotational force is applied by the spring 24, the rotation is restricted by the projection 25 formed on the arm member 22 being engaged with the rotation lever 17. Therefore,
In the stationary state, the feed pawl 23 of the arm member 22 is spaced apart from the ratchet gear 16, as shown in FIG.

Next, the operation of the present invention having such a configuration will be explained.

If you want to feed the paper manually first, press platen 2.
By rotating a manual operation knob (not shown) fixed to the rotating shaft 3 clockwise or counterclockwise, the recording paper can be moved forward or backward at a pitch set by the moderation gear 14. At this time, since the feed pawl 23 of the arm member 22 is separated from the ratchet gear 16,
The platen 2 can be rotated with a light operation.

Next, when the plunger 13 is driven after printing one line, the arm member 22 first moves counterclockwise around the support shaft 18 of the rotary lever 17 against the bias of the spring 24, as shown in FIG. By being rotated, the feed pawl 23 of the arm member 22 is engaged with the ratchet gear 16, and then the plunger 13 is further sucked, so that the arm member 22 and the rotation lever 17 are integrated, and the arm member 22 is rotated. The ratchet gear 16 is rotated by being rotated counterclockwise about the rotating shaft 3 of the platen 2 against the bias of the spring 20, so that the platen 2 is rotated by a predetermined angle and the recording paper is fed by a predetermined amount. .

When the plunger 13 becomes inoperative at the end of paper feeding, the rotating lever 17 and the arm member 22 are rotated clockwise by the force of the spring 20 and the spring 24, returning to the state shown in FIG.
The feed pawl 23 is separated from the ratchet gear 16.

FIG. 6 shows another embodiment, in which the arm member 22 is biased clockwise by a coil spring 25 wound around the support shaft 18 of the rotating lever 17 instead of the spring 24. .

(F) Effects of the Invention As described above, the paper feeding device of the present invention is configured to feed paper by rotating the platen using a ratchet mechanism, and furthermore, the ratchet mechanism is removed from the platen except when feeding paper, thereby allowing the platen to rotate freely. With this structure, it is possible to perform stable paper feeding with a simple mechanism, and it also has effects such as easy manual paper feeding and easy assembly.

[Brief explanation of drawings]

FIG. 1 is a side view showing a conventional example of a paper feeding device, FIG. 2 is a plan view of the same, FIG. 3 is a side view showing a paper feeding device of the present invention, and FIG. 5
The figure is a side view showing the operating state of FIG. 3, and FIG. 6 is a side view showing another embodiment. 2...Platen, 16...Ratchet gear, 1
7... Rotating lever, 22... Arm member.

Claims (1)

[Claims] 1 In a paper feeding device that feeds paper by rotating a platen, there is a ratchet gear that constitutes a ratchet mechanism that is fixed to the rotating shaft of the platen, and a rotary gear that is similarly rotatably attached to the rotating shaft of the platen. a lever, means for biasing the rotary lever in one direction, stopper means for restricting rotation of the rotary lever to a predetermined position by the biasing means, and one end rotatably attached to the rotary lever; an arm member having a feed pawl that is engaged with the ratchet gear, the other end of which is engaged with a plunger that is driven during paper feeding; and an arm member that is arranged such that the feed pawl of the member is spaced apart from the ratchet gear. A paper feeding device characterized by comprising means for applying force.