JPH028782Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a paper feeding mechanism of a printer. In the conventional printer paper feeding mechanism, as shown in the plan view and side view of FIG. 1, main arms 1a and 1b support a roller group 2, and sub-arms 3a and 3b
are adapted to support the roller group 4, and the main arms 1a and 1b are biased upward by springs 6a and 6b to bring the roller group 2 into uniform contact with the platen 11, and the sub-arms 3a and 3
b is biased upward by springs 5a and 5b to bring the roller group 4 into uniform contact with the platen 11. When the release lever 7 is rotated counterclockwise, the shaft 7a rotates, and the release pins 9a and 9b provided on the release arms 8a and 8b pull down the main arms 1a and 1b, so that the roller group 2 is separated from the platen 11. do. The stopper pins 10a and 10b provided on the main arms 1a and 1b are connected to the sub arm 3a.
and 3b in the clockwise direction, the roller group 4 is separated from the platen 11.

In this way, conventional devices have extremely complex mechanisms, require a large mounting space, and have a large number of parts.
The drawbacks were that assembly took time and maintenance was troublesome. In addition, since roller groups 2 and 4 are each supported by a single long shaft, uneven contact may occur due to shaft curvature or roller wear, making it difficult to completely prevent paper from skewing. It was hot.

In order to eliminate the above-mentioned drawbacks, the present invention provides a paper shoot having a curved surface that curves along the circumferential surface of the platen and has 2N (N is a positive integer) windows formed in two parallel rows, and a paper shoot that fits into the windows of this paper shoot. A single plate spring comprises a plurality of rollers mounted on the paper, roller shafts that support two rollers at a time, and leaf springs whose centers are fixed to the paper chute and whose ends bias the roller shafts toward the platen. This biases the four rollers surrounding the leaf spring almost independently, and will be described in detail below with reference to the drawings.

FIG. 2 is a plan view and a side view showing an embodiment of the present invention, in which reference numeral 12 denotes a paper sheet having shoulders 12a and 12b, and a curved surface curved along the circumferential surface of the platen 11, and 13f ₁ ,13
f ₂ , 13r ₁ and 13r ₂ are windows formed in two rows in parallel on the curved surface of the paper shoot ₁₂ ;
f ₂ , 14r ₁ and 14r ₂ are windows 13f ₁ , 13f ₂ , 13
Grooved arms formed by bending the opposing ends of r ₁ and 13r ₂ downward; 15f and 15r are rollers loosely fitted into the grooves of the grooved arm parts 14f ₁ , 14f ₂ , 14r ₁ and 14r ₂ ; The shafts 16f ₁ , 16f ₂ , 16r ₁ and 16r ₂ are fitted to both ends of the roller shafts 15f and 15r, respectively, and the windows 13f ₁ , 13f ₂ , 13
Feed rollers 17 fitted in r ₁ and 13r ₂ have their central portions fixed to the paper shoot 12 and roller shafts 15f and 15r at both ends connected to the platen 1.
leaf springs 18a and 18b biasing in direction 1;
The paper chute 12 is attached to the shoulders 12a and 12b.
19a and 19b are springs biasing the paper shoot 12 to rotate clockwise; 20 is a long hole 20;
The release lever 21 is a release lever having a diameter a and rotatably supported on a shaft 20b, and 21 is a release shaft made by bending a bar with an oval cross section into an L shape and providing a post 21a at the bent end. The pin 21a is loosely fitted into the long hole 20a of the release lever 20. 22
and 23 have stoppers 22a and 23a for restricting the rotation of the paper shoot 12, and the support shaft 18
This is a side frame that fixes the shaft 20b to a and 18b and rotatably supports the release shaft 21. Note that the springs 19a and 19b are given stronger springiness than the leaf spring 17. Also windows 13f ₁ , 13f ₂ , 13r ₁ and 13
r ₂ , grooved arms 14f ₁ , 14f ₂ , 14r ₁ and 14
r ₂ , roller shafts 15f and 15r, feed roller 1
6f ₁ , 16f ₂ , 16r ₁ and 16r ₂ , leaf spring 17
Although only the right half has been described, as shown in the figure, they are also provided at symmetrical positions on the left half.

The operation in the above configuration will be explained. First, the paper chute 12 is rotated clockwise by the biasing force of the springs 19a and 19b, but the stopper 2
2a and 23a, and is stopped at the position shown in FIG. Also, roller shafts 15f and 15
r is biased toward the platen 11 by the biasing force of the leaf spring 17. At this time, the feed roller 16
f ₁ , 16f ₂ 16r ₁ and 16r ₂ are in pressure contact with the peripheral surface of the platen 11, and roller shafts 15f and 1
5r is the grooved arm portion 14f ₁ , 14f ₂ , 14r ₁ and 1
It is floating in the middle of the 4r ₂ groove. Therefore, in this state, a biasing force due to the bending and twisting of the leaf spring 17 acts on the roller shafts 15f and 15r, and the feed rollers 16f ₁ , 16f ₂ , 16r ₁ and 16r ₂ receive the biasing force almost independently. Therefore, the paper (not shown) can be pressed almost evenly, and the platen 11
Paper can be fed by rotating.

Next, when the release lever 20 is rotated counterclockwise about the shaft 20b, the pin 21a loosely fitted in the elongated hole 20a is rotated, and the release shaft 21 is rotated. Since the release shaft 21 has an oval cross section, the long side pushes up the paper shoot 12, and as shown in FIG.
It rotates counterclockwise using 8b as the rotation axis. Therefore, feed rollers 16f ₁ , 16f ₂ , 16r ₁ and 1
6r ₂ is separated from the platen 11. Note that the feed rollers 16f ₁ , 16f ₂ , 16r ₁ and 16r ₂ are the support shaft 1
By appropriately selecting the positions of 8a and 18b, they can be separated from the platen 11 by an equal distance. That is, when the paper chute 12 is rotated by a certain angle, the strokes of the front row feed rollers 16f ₁ and 16f ₂ are large, and the strokes of the rear row feed rollers 16r ₁ and 1 are large.
6r ₂ stroke becomes smaller. however,
The movement trajectory of the front row feed rollers 16f ₁ and 16f ₂ has a large circumferential component of the platen 11 and a small radial component. On the other hand, the moving locus of the feed rollers 16r ₁ and 16r ₂ has a small component in the circumferential direction of the platen 11 and a large component in the radial direction. Therefore, the feed roller 16
f ₁ , 16f ₂ , 16r ₁ and 16r ₂ and support shaft 18a,
18b at appropriate positions, the feed rollers 16f ₁ , 16f ₂ , 16r ₁ and 16r ₂ can be separated from the platen 11 by an equal distance.
The same applies to the curved surface of the paper shot 12, so that the gap between the curved surfaces of the platen 11 and the paper shot 12 can also be spaced uniformly along the platen 11. Therefore, the feed rollers 16f ₁ , 16f ₂ , 16r ₁ and 16r ₂ and the paper chute 12 are moved along the circumferential surface of the platen 11.
The amount of separation from 1 can be made the minimum necessary. In this way, platen 11 and paper sheet 1
If the gap between the two is made small, the paper will not be bent, so that the paper will be smoothly turned and guided along the platen 11 when the paper is inserted, and it can be easily pulled out upward.

As explained in detail above, according to the present invention, 1
Since the four feed rollers can be biased almost independently using a single leaf spring, the entire mechanism can be made extremely simple, lightweight and thin, and since the number of parts is reduced, assembly is easy and maintenance is simple. There is a certain effect. Further, since the feed rollers are supported two by two on relatively short roller shafts, the pressing force of the feed rollers becomes uniform, which also has the effect of eliminating skewed feeding of the paper.

[Brief explanation of drawings]

1 is a plan view and a side view showing a conventional paper feeding mechanism, FIG. 2 is a plan view and a side view showing an embodiment of the present invention, and FIG. 3 is an explanatory diagram of the operation of the embodiment. 11...platen, 12...paper shoot,
13f ₁ , 13f ₂ , 13r ₁ and 13r ₂ ...window, 1
4f ₁ , 14f ₂ , 14r ₁ and 14r ₂ ... grooved arm portion,
15f and 15r...Roller shaft, 16f ₁ , 16
f ₂ , 16r ₁ and 16r ₂ ... feed roller, 17...
...Plate spring, 18a and 18b...Support shaft, 19
a and 19b...spring, 20...release lever, 21...release shaft, 22 and 23...side frame.

Claims (1)

[Scope of utility model registration request] A paper shoot having a curved surface that curves along the circumferential surface of a platen and has 2N (N is a positive integer) windows formed in two parallel rows; a plurality of rollers fitted in the windows of the paper shoot; A roller shaft supporting two rollers each, and a leaf spring fixed to the paper chute at the center and biasing the roller shaft toward the platen at both ends, and four rollers surrounding the leaf spring by one leaf spring. A printer paper feed mechanism characterized by biasing almost independently.