JPH05306027A - Sheet feeder for printer - Google Patents

Abstract

PURPOSE:To provide cost reduction in a sheet feeder for printer which facilitates the attachment/removal of the sheet feeding tray without causing the dislocation of a paper sheet at the time of attaching/removing the feeding tray. CONSTITUTION:A hopper plate is supported so as to be rotated freely at the bottom part of a sheet feeding tray 28, and a hopper shaft 30 where a force for pressing the hopper plate upward is applied passes through, protruding from the side wall of the sheet feeding tray 28. A lock cam 26 in an approximately fan shape whose outer periphery lower surface serves as a cam surface 26b is provided so as to be oscillated freely at the inner side surface of a tray receiver 15. At the initial position of the cam, the rotation of the lock cam in the attaching direction of the sheet feeding tray 28 is restricted, and the rotation at a prescribed angle in the opposite direction is permitted. The cam surface 26b is declined along the attaching direction of the sheet feeding tray 28 when the cam is located at the initial position, and is located at a position so as to be engaged with the edge part of the hopper shaft 30 when the sheet feeding tray 28 is attached. The hopper shaft 30 is engaged with the lock cam 26 to be pressed down forcibly at the time of attaching/removing the sheet feeding tray 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for a printer for feeding cut sheets to serial dot printers, electrophotographic recording devices, facsimiles and the like.

[0002]

2. Description of the Related Art When feeding cut sheets to a printer, there is a system in which the cut sheets are stored in a paper feed tray in a stacked state and the paper feed tray is attached to the printer to automatically feed the cut sheets to the printer. Generally adopted.

The printer side is provided with a tray receiver for detachably receiving the paper feed tray, and the tray receiver is provided with a picking roller for kicking the uppermost paper on the paper feed tray one by one. The paper tray is equipped with a hopper plate that pushes up the stored paper onto the picking roller.

[0004]

However, in the prior art, when the paper feed tray is attached to the printer or removed from the printer, the paper comes into contact with the picking roller while the tray is moving. In order to prevent paper misalignment due to the paper feed tray, it is necessary to operate the lever to lower the hopper plate both when installing and removing the paper feed tray. There was a drawback.

Therefore, it is an object of the present invention to provide a paper feeding device for a printer, which does not cause the positional deviation of the paper when the tray is attached and detached, but is easy to attach and detach the paper feeding tray at low cost. ..

[0006]

In order to achieve the above object, the paper feeding apparatus according to the present invention is a paper feeding tray 28 in which cut sheets P are stored, and a fixing device for removably receiving the paper feeding tray. It is composed of a tray tray 15 that is opened.

A hopper plate 29, on which a single-cut sheet P can be placed, is rotatably supported on the bottom 28a of the paper feed tray 28, and the hopper plate is upwardly mounted on the lower surface of the tip of the hopper plate. A hopper shaft 30 to which a pushing-up force is applied is provided, and both ends of this hopper shaft project through the side wall of the paper feed tray 28. At least one of the inner surfaces of the tray receiver 15 is provided with a substantially fan-shaped lock cam 26 having a cam surface 26b on the outer peripheral lower surface so that the lock cam 26 can swing freely. The rotation of the cam surface 26b is restricted in the opposite direction but is allowed to rotate in the opposite direction at a constant angle. The cam surface 26b is substantially aligned with the mounting direction of the paper feed tray 28 when in the initial position. It is a downward slope and is in a position where the end of the hopper shaft 30 can be engaged when the paper feed tray 28 is mounted.

Then, the paper feed tray 28 is placed in the tray receiver 15
When it is mounted on the hopper shaft 30, the end portion of the hopper shaft 30 engages with the cam surface 26b of the lock cam 26, so that the hopper shaft 30 is forcibly pushed down against the pushing force applied to the hopper shaft. When the paper feed tray 28 is pushed to a position where the end of the hopper shaft 30 is disengaged from the cam surface 26b, the hopper plate 29 moves the hopper plate 29 until the uppermost cut sheet P reaches the picking position. It is pushed up by the pushing force given to the hopper shaft 3 at this time.
The end portion of 0 is located at a position facing the rear side surface 26c of the lock cam 26, and when the paper feed tray 28 is pulled out from the tray receiver 15, the end portion of the hopper shaft 30 is engaged with the rear side surface 26c of the lock cam 26. Lock cam 26
Is rotated by the above-mentioned fixed angle, and the hopper shaft is forcibly pushed down along the inner side surface 26c of the lock cam that has been rotationally displaced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the printer paper feeder according to the present invention will be described below with reference to the preferred embodiments shown in the accompanying drawings. First, the configuration on the printer body side will be described.
In FIG. 1, a carriage 3 is slidably received by guide shafts 1 and 2 supported by a pair of side plates (not shown), and a print head 4 is mounted on the carriage. A platen 5 rotatably driven by a paper feed motor (not shown) is located at a position facing the print head 4, and a friction roller 6 is in contact with this platen.

The friction roller 6 is rotatably supported by a lever 8 which is swingable about a shaft 7.
The spring force of the spring 9 elastically contacts the platen 5. Above the front end of the print head 4, a paper feed roller 10 and a pinch roller 11 that is elastically contacted with and follows the paper feed roller 10.
Is provided, and is driven in association with the platen 5 via the above-described paper feed motor during paper feed. Paper guides 12, 13, 14 are provided below the platen 5.
Are arranged.

Next, the tray receiver 15 arranged below the paper guide 13 will be described.

The tray receiver 15 includes a pair of side plates 16.
(Only one of them is shown in the drawing, but both are substantially bilaterally symmetrical.) Are arranged opposite to each other at a predetermined interval. And both side plates 16,
Plates 17, 1 located on its top, bottom and front
A space into which a paper feed tray 28 described later is inserted is defined by 8 and 19. Paper guides 17a, 18a and 19a are integrally formed on the plates 17, 18 and 19, respectively. Numerals 20 and 21 are picking rollers that are driven when the paper is taken out from the paper feed tray 28.
The lower part of the picking roller 20 penetrates the inside of the plate 17 through an opening (not shown). Behind the plate 19 is provided an oscillating body 23 that can oscillate around an axis 22. A plastic guide body 24 having a smooth upper surface and a load member 25 made of a material having a large friction coefficient such as rubber are fixed to the upper surface of the rocking body 23. Actually, two sets of the guide body 24 and the load member 25 are arranged so that they are located at a predetermined interval when viewed from the side, and the picking roller 21 is located at the intermediate position thereof. ing.

An engagement groove 16a is provided on the inner surface of the rear portion of the side plate 16. A fan-shaped lock cam 26 is rotatably attached to the inner surface of the front part of the side plate 16 by a shaft 27.
The lock cam 26 usually hangs down by its own weight as shown in the figure. The protrusion 26a is provided on the outer surface of the lock cam 26.
Is formed so as to project, and this projection is fitted in a groove 16b which is recessed in the inner surface of the side plate 16. This fitting restricts rotation of the lock cam 26 in the tray insertion direction, that is, to the right, but allows rotation in the opposite direction, that is, in the tray removal direction. However, such regulation of the lock cam 26 is not limited to the above-described configuration.
It is also possible to project on the inner surface of the.

Next, the paper feed tray 28 which is attached to and detached from the tray receiver 15 will be described with reference to FIGS. 1 and 2.

The paper feed tray 28 is formed so as to have a substantially box shape with an open upper surface, and the cut sheet P can be stored therein. A hopper plate 29 for receiving the stored cut sheets P is arranged on the bottom portion 28a of the tray 28, and the end portion 29a receives the hopper plate 29.
It is rotatably and slidably supported by b. A hopper shaft 30 to which a force for pushing the hopper plate 30 upward is applied is in contact with the lower surface of the tip of the hopper plate 29, and in this embodiment, a claw 29b vertically provided on the lower surface of the tip of the hopper plate 29.
Hugged by. Both ends of the hopper shaft 30 have through holes 28d formed in the side wall 28c of the tray.
To the side of the tray.

On the outer surface of the side wall 28c, a swing lever 31 is swingably supported around a shaft 32, and a hopper shaft 3 is formed in a through hole 31b of an arm 31a formed integrally.
Both ends of 0 are fitted. Shaft portions 33a and 33b of the movable member 33 are slidably fitted in guide grooves 28f and 28g formed in the tray side wall 28e along the tray insertion direction. The shaft portion 33b is projected from the outer surface of the side wall 28e by a predetermined length, and is provided on the side plate 1 of the tray receiver 15.
It is possible to engage with the engaging groove 16a provided in the groove 6.

A biasing spring 34 is stretched between the arm 31c of the swing lever 31 and the movable member 33 so as to apply a force for pushing the hopper shaft 30 upward. When the paper feed tray 28 is pulled out from the tray receiver 15, the movable member 33 is at the position shifted to the right as shown in FIG. 1, so the biasing spring 34 is contracted and the swing lever 31 is rotated. Did not give. Therefore, the hopper plate 29
2 is in a state of falling on the bottom portion 28a due to the weight as shown in FIG. In this embodiment, the hopper plate 29
Even when the sheet P is not present, the sheet P has dropped to the bottom portion 28a due to its own weight.

Therefore, the paper feed tray 28 is replaced with the tray receiver 15
The operation of mounting on the will be described. The paper feed tray 28 on which the sheets P are stacked is pushed rightward with respect to the tray receiver 15 as shown in FIG. Shaft part 3 of movable member 33
When 3b is located at the entrance of the engaging groove 16a of the side plate 16 of the tray receiver 15, the hopper shaft 30 is at the position A in FIG. When the shaft portion 33b of the movable member 33 comes into contact with the lower slope of the engagement groove 16a, the hopper shaft 30 moves to the position shown in FIG.
B position. Although the paper feed tray 28 is further pushed in, the shaft portion 33b of the movable member 33 is prevented from moving on the slope of the engagement groove 16a. Therefore, the movable member 33 is prevented from moving, but the swing lever 31 is pushed further together with the paper feed tray 28. Therefore, the biasing spring 34 is stretched as the paper feed tray 28 is pushed rightward, and the spring force is gradually increased. As a result, a rotational force in the counterclockwise direction acts on the swing lever 31,
The hopper shaft 30 receives a force that pushes it upward. However, at this time, the hopper shaft 30 is pushed up slightly and immediately contacts the cam surface 26b of the lock cam 26, and thereafter moves from the position C to the position D of FIG. 3 along the cam surface 26b. That is, although the biasing spring 34 is charged with a sufficient spring force as the paper feed tray 28 is pushed, the hopper shaft 30 is restrained by the cam surface 26b of the lock cam 26 so as to move substantially horizontally.

Then, the paper feed tray 28 is replaced by the tray receiver 15
When pushed into place, the hopper shaft 30 passes over the cam surface 26b of the lock cam 26.
Therefore, the restraint of the hopper shaft 30 is released and the hopper shaft 30 rises at a stretch (E in FIG. 3), and the hopper plate 29 rotates counterclockwise as shown in FIG.
Are pressed against the picking roller 20. That is,
The paper P comes into elastic contact with the picking roller 20 only when the paper feed tray 28 is pushed to a predetermined depth. At this time, the projecting portion 28j projectingly formed on the front surface of the paper feed tray 28 is formed through the through hole 19b of the plate 19 (see FIG. 1).
1 to displace the rocking body 23 from the state shown in FIG. 1 to the state shown in FIG.
It projects from the through hole 19c of a.

When the recess 28h at the rear of the guide groove 28g in FIG. 1 moves to a position facing the slope of the engaging groove 16a, the shafts 33a and 33b of the movable member 33 are moved to the left end side of the guide grooves 28f and 28g. Has moved to, especially the shaft 33
The b is allowed to move upward by the concave portion 28h, whereby the shaft portion 33b enters the position where it abuts the left end surface of the engaging groove 16a, so that the sheet feeding tray 28 is prevented from coming off.

In the state shown in FIG. 4, the picking roller 20,
When 21 is rotationally driven in the direction of the arrow, the uppermost sheet P is sent out. At this time, the lower two or three sheets of paper also try to be sent out together, but the load member 25 blocks the passage thereof, and only the uppermost one sheet is sent out.
Is passed in front of the print head 4 via a platen 5 and a friction roller 6, and predetermined printing is performed by the print head 4. Further, the paper feed roller 10 and the pinch roller 1
It is pulled out via 1.

Next, the operation of pulling out the paper feed tray 28 from the tray receiver 15 will be described. Paper tray 2
8 when pulling out 8 from the tray receiver 15,
When the sheet P remains on the sheet 8, the sheet P is pressed against the picking roller 20 as described above, and some sheets are projected near the picking roller 21. When the paper feed tray 28 is pulled out to the left in this state, the protrusion 28j on the front surface of the tray retracts, and the rocking body 23 returns to the state of FIG. 1 by its own weight. At the same time, the hopper shaft 30 is moved to the left.

At this time, as shown in FIG. 3, the hopper shaft 30 is located on the right side of the side surface 26c of the lock cam 26, so that the hopper shaft 30 moves toward the lock cam 26.
Engage the side surface 26c of the and swing it. The rocking of the lock cam 26 is allowed only up to the position where the lock cam 26 comes into contact with the plate 17 located on the upper surface side (the position indicated by the chain line in FIG. 3), and cannot rock further. Therefore, the hopper shaft 30 is attached to the side surface 2 of the lock cam 26.
A rapid drop is made along 6c (F → C in FIG. 3).

Therefore, the paper P on the hopper plate 29 is separated from the picking roller 20, and the paper tray 2
The upper several sheets of the paper P of No. 8 (this is slightly projected to the right from the paper feed tray 28) are not left behind on the tray receiver 15 side. When the hopper shaft 30 is retracted to the position of B in FIG. 3, the biasing spring 30 is contracted to its original state, so that the hopper plate 29 has fallen to the bottom portion 28a of the tray 28, and finally the paper feeding tray. 28 is completely removed from the tray receiver 15 as shown in FIG.

In the above embodiment, the movable member 33
Can be arranged on the outer surface of the side wall 28e, and the swing lever 31 can be arranged on the inner surface side of the side wall 28c. That is, which side of the side wall 28c or 28e the rocking lever 31 and the movable member 33 are to be arranged is merely a design problem.

The connecting structure of the swing lever 31 and the hopper plate 30 is not limited to the structure of the above embodiment. That is, the hopper plate 30 may be fixedly connected to the arm 31a of the swing lever 31.
In this case, the through hole 28d will be formed in an arc shape concentric with the shaft 32.

[0027]

According to the paper feeding apparatus of the present invention described in detail above, the paper feeding tray can be attached to and detached from the tray receiver by simply pushing in or pulling out the paper feeding tray, and any manual operation of the lever as in the prior art is possible. It is unnecessary. Therefore, it is very easy to attach and detach the paper feed tray. In addition, when the tray is attached / detached, particularly when the tray is attached, the positional deviation of the paper does not occur, so that the paper feeding operation does not occur and the paper can be stably supplied to the printer.

[Brief description of drawings]

FIG. 1 is a right side view, partially in section, showing a state where a paper feed tray is pulled out from a tray receiver.

FIG. 2 is a vertical cross-sectional view of a paper feed tray

FIG. 3 is an explanatory diagram showing a relationship between a rocker cam and a hopper shaft.

FIG. 4 is a sectional view showing a state in which a paper feed tray is attached to a tray receiver.

[Explanation of symbols]

 15 ... Tray receiver, 26 ... Lock cam, 26b ... Cam surface, 26c ... Lock cam side surface, 28 ... Paper feed tray, 28a ... Tray bottom, 28c, 28e ... Tray side wall, 29 ... Hopper plate, 30 ... Hopper shaft, 31 ... Swing lever, 31a ... Swing lever arm, P ... Single-cut sheet.

Claims (1)

[Claims] 1. A bottom portion of the paper feed tray, which comprises a paper feed tray (28) for storing cut paper sheets (P) and a fixed tray receiver (15) for detachably receiving the paper feed tray. A hopper plate on which the cut sheet can be placed is rotatably supported on (28a), and a hopper to which a force is applied to push up the hopper plate upward is provided on the lower surface of the tip of the hopper plate. A shaft (30) is provided, both ends of the hopper shaft project through the side wall of the paper feed tray, and the outer peripheral lower surface has a cam surface (26b) on at least one of the inner surfaces of the tray receiver. A substantially fan-shaped lock cam (26) is swingably provided. When the lock cam is in the initial position, its rotation is restricted in the mounting direction of the paper feed tray, but in the opposite direction. Is allowed to rotate at a constant angle, the cam surface is substantially a downward slope along the mounting direction of the paper feed tray when in the initial position, and the paper feed tray is mounted. When the paper feed tray is mounted on the tray receiver, the end of the hopper shaft engages with the cam surface when the paper feed tray is mounted on the tray receiver. When the shaft is forcibly pushed down against the pushing force applied to the hopper shaft, and the paper feed tray is pushed to a position where the end of the hopper shaft disengages from the cam surface, The hopper plate is pushed up by the push-up force applied to the hopper shaft until the uppermost cut sheet is in the picking position. Tsu end par shaft on the rear side of the lock cam side (26
When the paper feed tray is pulled out from the tray receiver, the end of the hopper shaft engages with the rear side surface (26c) of the lock cam so that the lock cam moves at the fixed angle. A printer paper feeder, wherein the hopper shaft is forcibly pushed down along a rear side surface (26c) of the lock cam which is rotated and displaced.