JPS6349465A - Printer - Google Patents

Abstract

PURPOSE:To reduce the cost of a printer, by providing a third gear which rotates together with a paper feed roller and a means for selectively engaging the third gear with a second gear thereby realizing automatic opening/closing of a roller supporting arm without employing an expensive plunger. CONSTITUTION:When a roller 3 is not required to be opened, a gear 4 is disengaged from a gear 15 thereby a cam 7 is not rotated even if a paper feed roller 1 is rotated. When the roller 3 is opened in order to insert a paper automatically, a head carrier 16 is moved in the direction of an arrow 26 and a slant section 10 is pushed down by a projection 18 so as to rotate an arm 9 counter-clockwise, thereby the gear 4 is moved in the direction of an arrow 24 and engaged with the gear 15. When the paper feed roller 1 is rotated in the direction of an arrow 28, the cam 7 is rotated in the direction of an arrow 69 immediately as a paper 30 is inserted by halfway thereby a projection 29 is pushed up and the roller 3 is opened. When the paper feed roller 1 rotates by predetermined amount, the cam 7 is rotated to the end position of the cam face for pushing up the projection 29 immediately upon the insertion of the upper end of the paper 30 above the roller 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a printer that prints on a recording medium using a print head, and more particularly to an automatic opening/closing means for a paper presser roller.

[Conventional technology]

Conventionally, this type of printer uses a plunger 3 as shown in Fig. 2 as an automatic opening/closing means for the paper holding roller.
2 suction action was used. In the figure, the paper 30 is fed by the rotation of the feed roller 21 while being guided by a guide 50.

When the plunger 32 is not in suction operation, the force of the spring 13 causes the paper pressing roller 3 at the tip of the roller support arm 2 to wrap the paper 30t around the roller IK. At this time, printing can be performed using the print head 40 fixed to the head carrier 16. Further, when setting the paper, the plunger 32 performs a suction operation and rotates the arm 2 counterclockwise against the spring force, thereby bringing it into the second prisoner state.

[Problem that the invention seeks to solve]

The conventional printer described above requires a plunger to open and close the paper holding roller, and this plunger needs to be a so-called keep solenoid that has a permanent magnet inside to keep the roller open (second prisoner) for a certain period of time. This is a major obstacle to lowering the price of printers.

[Means for solving problems]

The printer of the present invention includes a paper feed roller, a print head that prints on the paper wrapped around the outer peripheral surface of the feed roller,
A first arm to which a pressing member that presses the paper against the outer peripheral surface of the paper feed roller is fixed, and a first arm that is arranged in a position where it can come into contact with the first arm, and in a certain rotation range, the first arm is moved in the pressing direction of the pressing member. a cam shaped to move the first arm in the opposite direction and return the first arm to the pressing direction at a certain rotational position; a first gear integrally formed with the cam; and a rotation of the first gear. a second arm rotatably attached to the center and whose neck vibrates on the rotation center; a second gear having the rotation center on the second arm and meshing with the first gear;
It has a third gear that rotates with the rotation of the paper feed roller, and means for selectively meshing the second gear and the third gear.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows one embodiment of the present invention, (8) is a plan view, and (B) is a sectional view taken along line A-A. The shaft 12 (partially shown) is rotatable in the direction of the arrow 23.
The roller 3 applies pressure to the paper feed roller 1 side. Further, the roller support arm 2 has a projection 29 that engages with the cam 7 on a part thereof. Cam 7 and gear 6 integrally formed with cam 7
is mounted so as to be rotatable about axis 8. axis 8
is fixed to the side plate 60. A dogleg-shaped arm 9 is attached to the shaft 8 and is rotatable around the shaft 8. Another gear 4 that meshes with the gear 6 is fixed to one end of the arm 9, and a slant portion 10 (see Fig. 1) is fixed to the other end. (5)) is formed. Further, the arm 9 is urged in the direction of arrow 25 by a spring 11. The gear 15 is attached to the roller shaft so as to rotate together with the paper feed roller 1. Reference numeral 1a denotes a driven roller for facilitating feeding of the paper 30. A projection 18 is provided on the carrier 16 of the print head 40, and the carrier 16 is slidable in the axial direction of the support shafts 71,72.

Next, the operation of the embodiment of the present invention will be explained.

When there is no need to release the roller 3, the gear 4 is separated from the gear 15 as shown in Fig. 1, and the cam 7 does not rotate even if the paper feed roller 1 rotates.
When opening the head carrier 16, first the head carrier 16 is
), the protrusion 18 pushes down the slant portion 10 and rotates the arm 9 counterclockwise, so the gear 4 moves in the direction of arrow 24 as shown in FIG. The paper feed roller 1 moves and meshes with the gear 15.
When the paper 30 is inserted halfway, the cam 7 rotates in the direction of the arrow 69, pushing up the protrusion 29 and opening the row 23 as shown in FIG. 4. When the paper feed roller 1 further rotates by a certain amount, the upper end of the paper 30 is inserted above the row 23, and at the same time the cam 7 rotates to the end position of the cam surface that pushes up the protrusion 29 (fifth
Figure (B)). When the gear 4 meshes with the gear 15 and starts rotating, a force acting on the gear 4 in the direction of the arrow 24 causes the protrusion 18 to separate from the slant portion 10 as shown in FIG. 5 (5). (As shown in the figure, gear 4 maintains meshing with gear 15.)

When the paper feed roller 1 further rotates in the direction of arrow 28,
The cam 7 ends contact with the cam surface pushing up the protrusion 29, and the roller support arm 2 closes as shown in FIG. 6, causing the roller 3 to press the paper 30 onto the paper transport roller. Finally, the paper feed roller 1 rotates slightly in the direction of the arrow 31, and the force that forces the gear 4 into the gear 15 is released, so the arm 9 is pulled by the spring 11 and disengaged, as shown in FIG. .

〔Effect of the invention〕

As described above, the present invention has the effect of reducing the price of the printer because the automatic opening and closing of the roller support arm can be realized without using a large output and expensive plunger.

[Brief explanation of the drawing]

Figures 1 (5) and (B) show embodiments of the present invention, 5) is a plan view, (B) is a sectional view taken along line AA of (5), and Figure 2 (A)
, (B) is a side view showing a conventional printer, FIG. Figure 4 is Figure 3 (B)
5) is a cross-sectional view showing the continued operation of Figure 5, (■) is a plan view showing the continued operation of Figure 4, (B) is a C-C sectional view of the prisoner,
FIG. 6 is a sectional view showing the continuation of the operation of FIG. 5 (FIG. 7). FIG.・Roller support arm, 3...Roller, 4...Gear, 5...Shaft, 6...Gear, 7...
...Cam, 8...Shaft, 9...Arm, 10...Slant section, 11...Spring, 12...Shaft , 13...Spring, 14...Shaft, 15...Gear, 1
6...Head carrier, 17...Print head, 18...Protrusion, 19.19'...
...Shaft, 21...Paper guide, 22...
...Small roller, 20°23~28.31...
・Arrow, 29... Protrusion, 30... Envy

Claims (2)

[Claims] (1) A printer including a paper feed roller, a print head that prints on paper disposed on the outer circumferential surface of the feed roller, and a first arm to which a pressing member that presses the paper against the outer circumferential surface of the feed roller is fixed. The first arm is disposed at a position where it can come into contact with the first arm, and in a certain rotational range, the first arm is moved in a direction opposite to the pressing direction of the pressing member, and in a certain rotational position, the first arm is moved in the direction opposite to the pressing direction of the pressing member. a cam shaped to return in the pressing direction; a first gear formed integrally with the cam; and a second gear, which is rotatably attached to the rotation center of the first gear and whose neck vibrates on the rotation center. an arm, a second gear having a rotation center on the second arm and meshing with the first gear, a third gear rotating with rotation of the paper feed roller, and the second gear.
and means for selectively meshing the gear and the third gear. (2) The printer according to claim (1), wherein the selective engagement of the second gear and the third gear is performed in response to neck vibration motion of the second arm. .