JPS62138268A - Paper feeder of printer - Google Patents

Abstract

PURPOSE:To surely prevent the failure and falling off of a plate spring with an extremely simple constitution, by controlling the unnecessary motion in the falling off direction of the plate spring supporting a pressure roller with an elastic body. CONSTITUTION:An elastic body 20 consists of resins having elasticity such as sponge, rubber, etc. When a friction axis 5 rotates and the another end bending part 12 of a plate spring 10 is put on a notched plane 51 correspondingly thereto, the plate spring 10 is pivoted downward by a fixed angle utilizing its one end as a fulcrum and a pressure roller 7 leaves from a platen 3 keeping a space therefrom. Then, one end of the plate spring 10 is made to approach the elastic body 20 to face it having a space of d. If vibration or shock is exerted to a printer in that state, the plate spring 10 can move idle and the part idly supported to this projected piece 82 tends to separate to fall off. If the plate spring 10 is likely to fall off and shift upward to the support part, its one end touches the elastic body 20 and is received therewith and the position is controlled so that it does not shift any more in the falling off direction. In that case, the shock in contact therewith is absorbed by the elastic body 20.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a paper feeding device for a printer used as an output device for personal computers, word processors, etc., and more particularly to a technique for preventing a leaf spring supporting a pressure roller from falling off.

Among conventional paper feeding devices for printers, there is one in which a pressure roller (paper feeding roller) is brought into pressure contact with a platen sandwiching the paper, and the paper is fed by rotation of the platen. In such paper feeding devices, the structure shown in Fig. 3 has been conventionally used as a mechanism for pressing the roller against and separating from the platen, because it has a simple structure and can be constructed at low cost. There is.

The paper feeding device shown in FIG. 3 includes a base 1 having rising walls 2.2 at both ends, a platen 3 rotatably supported between the rising walls 2.2 of this base 1, and Platen 3
a paper guide 4 curved in an arc along the circumferential surface of the platen 3; a friction shaft 5 rotatably supported below the platen 3 with its axial direction parallel to the platen 3; Mounting hole 81 formed in mounting base (plate) 8
A mounting hole 61 formed at one end is loosely fitted into the protruding piece 82 on the periphery, and the other end is placed on the friction shaft 5 and is rotatably supported by a leaf spring 6 and an intermediate part of the leaf spring 6. It is configured by a pressure roller 7. The paper guide 4 has a hole at the mounting position of the pressure roller rough, and the pressure roller 7 is fitted therein. The paper guide 4 extends parallel to the surface of the base 1 rearward from the end of a curved part that curves from the front surface of the platen along the rear surface, and the extended part is placed on the mounting base 8 and fixed with screws. .

A plurality of pressure rollers 7 are coaxially arranged in parallel to the axial direction of the platen 3. The leaf springs 6.6 supporting the rollers 7.7 are integrally formed into a generally comb-like shape with one loosely fitted end connected to the leaf springs 6.6. leaf spring 6.6
- The friction shaft 5 on which the other end is placed has a notch 51 formed in its axial direction.

In the above configuration, when the friction shaft 5 is rotated, the leaf spring 6,6...fist moves up and down with its loosely supported end as a fulcrum due to the step between the circumferential surface of the shaft 5 and the notch surface 51. The pressure roller 7.7 is swung according to the level difference.
... are pressed against and separated from the platen 3 via the paper.

The paper is sandwiched between the platen 3 and the pressure roller 7.7.phi., and is fed as the platen 3 rotates.

Problems to be Solved by the Invention However, according to the conventional leaf spring support structure described above, the mounting hole 61 formed at one end of the leaf spring 6 is loosely fitted into the protrusion 82 formed at the inner edge of the mounting hole of the mounting base 8. Since it is a simple product, if horizontal vibration or vertical vibration is applied during product inspection, or if shock is applied during use, the following problems may occur.

As shown in FIG. 4, when the pressure roller 7 is pressed against the platen 3 in the obliquely installed state of the leaf spring 6, the reaction force of the pressure received from the platen 3 causes the leaf spring 6 to move between the Flixiron shaft 5 and the protrusion 8. Since it is held in such a way that it does not move around in between, it does not cause much of a problem. However, when the leaf spring swings downward and the pressure roller 7 is disengaged from the platen 3, the leaf spring 6 becomes free-floating and tilts downward at a steep angle. The fitting becomes extremely easy to come off. If shock or vibration is applied in this state, the leaf spring may easily come off and fall off. If the leaf spring 6 falls off in this way, the printer will no longer be able to perform its original functions. Therefore, some kind of measure for regulating and holding the leaf spring 6 is required.

Means for Solving the Problems This invention has been devised in view of the above points, and it is possible to restrict the unnecessary movement of the leaf spring body as described above, and to surely prevent the leaf spring body from falling off with a simple structure. The purpose is to make it possible.

In order to achieve this object, the present invention includes a platen rotatably supported on the upper part of the base, and an arcuate curved shape along the circumferential surface of the platen, with the rearward extending end extending from the base. a paper guide supported by a mounting base provided on the mounting base; a friction shaft rotatably supported below the platen with its axial direction parallel to the platen; and a friction shaft having a cutout surface in the axial direction; a plate spring body which is loosely fitted and supported, and whose other end is placed on the Flixiron shaft and is installed diagonally;
In a paper feeding device for a printer, the pressure roller is rotatably supported at an intermediate portion of the leaf spring body and is pressed into contact with and released from the platen. The present invention is characterized in that an elastic body is attached to the mounting base or the paper guide extension so as to face the gap, and the elastic body restricts the movement of the leaf spring body.

Function In the above configuration, when the friction shaft rotates, the leaf spring body rotates downward using the loosely supported part as a fulcrum, and when the pressure roller separates from the platen, the leaf spring body tilts downward at a slightly steep angle. This makes it easy for it to come off from where it was loosely fitted and supported. If vertical vibration, lateral vibration, or shock is applied in this state, the temporary spring body will try to move in the direction of detachment.

However, since its one end faces the elastic body provided on the mounting base with a slight gap, when the leaf spring body moves in the direction of removal, it comes into contact with this elastic body and the receiver is stopped. Therefore, further movement of the leaf spring body is restricted, and the leaf spring body is prevented from falling off.

Embodiments Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2 shown below, the same parts as in FIGS. Omitted. What is new is that an elastic body is provided at a predetermined position on the mounting base or paper guide corresponding to one loosely fitted end of the temporary spring body supporting the pressure roller.

FIG. 1 is a perspective view showing the main parts of a paper feeding device according to the present invention;
Figure 2 is a side sectional view of the same, where 1 is the base, 3 is the platen, and 4 is the side sectional view.
is a paper guide, 5 is a friction shaft, 10 is a leaf spring, 7 is a pressure roller, 8 is a mounting base, and a plurality of mounting holes 81 (three in the figure) for supporting the leaf spring 10 are connected to the wall. At the same time, a projecting piece 82 is formed at the center of the lower side of the mounting hole 81, into which the mounting hole 11 of the leaf spring 10 is loosely fitted.

A plurality of plate springs 10 are integrally formed in a substantially comb-like shape with one end thereof connected. A mounting hole 11 is formed at one end of the leaf spring 10. The other end, which is placed on the friction shaft 5, is bent in one direction to form a bent portion 12. The bent portion 12 is bent upward and is formed in a direction away from the friction shaft 5.

A notch hole 13 is formed in the middle portion of the leaf spring 10 to serve as a mounting portion for a pressure roller.

Bearing portions 15 are formed in concave shapes on both sides 14.14 of the notch hole 13 to fit and support the rotating shaft of the pressure roller rough.

The leaf spring 10 has the mounting holes ILII-- at one end supported by loose fitting in protrusions 82 formed in the mounting holes 81 of the mounting base 8 erected on the base 1 behind the platen 3, and By placing the bent portion 12 at the other end on the flexible shaft 5, the platen is installed obliquely from the rear to the front and downward. Pressure rollers 7, 7, . . . supported by leaf springs 10 are opposed to the platen 3 so as to be able to come into contact with and separate from the platen 3. The direction of rotation of the leaf spring 10 with one loosely supported end as a fulcrum is made to coincide with the radial direction of the platen 3.

The leaf spring 10 contacts the circumferential surface or notched surface 51 of the friction shaft 5 at the bent portion 12, and as the friction shaft 5 rotates, it fits loosely at an angle corresponding to the step between the circumferential surface and the notched surface 51. It swings and rotates up and down using one supported end as a fulcrum. As a result, the pressure roller 7 is brought into pressure contact with the platen 3 with the paper being fed along the paper guide 4 interposed therebetween, or is separated from the platen 3. The paper is sandwiched between the platen 3 and the pressure roller 7, and the paper is fed by rotation of the platen 3.

In the above configuration, the upper end of the curved portion of the paper guide 4 at the rear of the platen extends further rearward in parallel with the surface of the base 1, and this extending portion 41 is connected to the mounting base 8.
It is placed and supported on top.

Elastic bodies 20φ are attached to the lower surface of the extending portion 41 at positions corresponding to one ends of the leaf springs 10, respectively.

The elastic body 20 is attached to one end of the leaf spring 10 with a predetermined gap d therebetween. This gap d is, for example, the leaf spring 10
When one end is closest to the elastic body 20, that is, when the leaf spring 10 is rotating downward about the fulcrum and the pressure roller 7 is detached from the platen 3, it should be close to the elastic body 20 by about 0.2 mm. Set.

The elastic body 20 is made of a flexible resin such as sponge rubber. The elastic bodies 20 may be provided one for each leaf spring 10, or may be provided only for the leaf spring 10 in the center. Furthermore,
They may be provided corresponding to the leaf springs 1o110 at both ends. Moreover, the shape is not limited to the rectangular block shape shown in the embodiment, but can be modified in various ways.

Note that the leaf springs to which the present invention is applied are not limited to those in which a plurality of leaf springs are integrally connected in a comb-teeth shape as shown in the embodiment, but may be constructed in such a manner that a single leaf spring is assembled separately.

In the above configuration, when the friction shaft 5 rotates and the other end bent portion 12 of the temporary spring 10 corresponds to the notch surface 51 and rests on it, the leaf spring 10 rotates downward by a predetermined amount using one end as a fulcrum. do. When the leaf spring 10 rotates, the pressure roller 7 is separated from the platen 3 at a distance. Then,
One end of the leaf spring 10 is closely opposed to the elastic body 20 with the gap d mentioned above.

In this state, when longitudinal vibration, lateral vibration, or impact is applied to the printer, the leaf spring 10 is free to move, is tilted downward, and is supported in a loosely fitted state, so the protrusion 82 The fitted and supported part comes loose and tries to fall off. When the leaf spring 10 comes off and tries to fall off, for example, when it tries to move upward with respect to the support part, one end of the leaf spring 10 comes into contact with the elastic body 20, and the retainer is stopped and its position is restricted so that it does not move any further in the detachment direction. Ru. At this time, since the elastic body 20 has flexibility, the elastic body 20 deforms more flexibly and absorbs the impact upon contact. With this, the leaf spring 10 is flexibly positioned and held. Therefore, the leaf spring 10 will not be deteriorated, distorted, or deformed or damaged due to a collision with the elastic body 20. In this respect, it is necessary to avoid forming the elastic body 20 rigidly and rigidly.

In this manner, the leaf spring 10 is prevented from coming off and falling off.

Of course, the leaf spring 10 rotates upward, and the pressure roller 7
Needless to say, even when the platen 10 is pressed against the platen 3, the position of the leaf spring 10 is regulated by the same operation as described above, and the leaf spring 10 is prevented from falling off. However, in this case, one end and the other end of the leaf spring 10 are pressed around the protrusion 82 that is loosely fitted and supported and against the circumferential surface of the friction shaft 5, respectively, due to the reaction force due to the pressure contact with the platen 3, and the two ends are pressed against each other. Since it is held in place, there is no need to give much consideration to preventing it from coming off or falling off.

Therefore, the present invention is extremely effective when applied to prevent the leaf spring 10 in a freely movable state as described above from coming off or falling off. The effectiveness of prevention is enormous.

In addition, in the case of the embodiment, the elastic body 20 is connected to the paper guide 4.
The mounting base 8 is designed to be attached to the extension portion 41 of the
The mounting portion of the paper guide 4 may extend rearward, and the elastic body 20 may be attached to the lower surface of this extension so as to face one end of the leaf spring 10.

As described in detail, according to the present invention, the unnecessary movement of the leaf spring supporting the pressure roller in the disengagement direction is regulated by the elastic body, and the leaf spring can be moved with an extremely simple structure of just attaching the elastic body. It can reliably prevent it from coming off or falling off.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the main parts of a paper feeding device of a printer according to the present invention, Fig. 2 is a side sectional view thereof, Fig. 3 is a perspective view showing a conventional paper feeding device, and Fig. 4 is a side view thereof. FIG. 1-Friction base, 3-Platen, 4-Paper guide, 41-Extending portion, 8-0-Mounting base, 5-Friction shaft, 10-Plate spring (body ), 7 φ pressure roller, 20... elastic body, d... writing gap. Patent applicant: NEC Home Electronics Figure 2 Figure 4

Claims (3)

[Claims] (1) A platen rotatably supported on the upper part of the base, and an arc curved shape formed along the circumferential surface of the platen, with an end extending toward the rear of the platen supported by a mounting base provided on the base. a friction shaft rotatably supported below the platen with its axis parallel to the platen, and having a notched surface in the axial direction, one end of which is loosely supported on the mounting base behind the platen, A printer comprising: a plate spring body whose other end is placed on the friction shaft and is disposed obliquely; and a pressure roller rotatably supported at an intermediate portion of the plate spring body so as to be in pressure contact with and detach from the platen. In the paper feeding device, an elastic body for regulating one end of the leaf spring body is provided with a predetermined gap at a position corresponding to the one end of the leaf spring body of the mounting base or the paper guide extension. A paper feeding device for a printer, characterized in that: (2) When the pressure roller is separated from the platen, a predetermined gap is formed between the elastic body and one end of the leaf spring body. A paper feeding device for the printer according to item 1. (3) A paper feeding device for a printer according to claim 1 or 2, wherein the elastic body is made of sponge, resin, or the like.