JP5827854B2 - Paper feeder - Google Patents

Description

  The present invention relates to a sheet feeding device that stacks either a sheet or an envelope on a sheet feeding table and feeds the uppermost sheet or envelope by a sheet feeding roller.

  In general, printing apparatuses (image forming apparatuses) that print (form) images and characters on paper and envelopes are frequently used for home use or business use, such as inkjet printing apparatuses, stencil printing apparatuses, laser beam printers, and thermal transfer printing apparatuses. Has been.

  The above-described printing apparatus is provided with a paper feeding device that stacks either a paper sheet or an envelope on a paper feed tray and feeds the uppermost paper sheet or envelope by a paper feed roller.

  As an example of this type of paper feeding device, in particular, when feeding envelopes, even if a large amount of envelopes are loaded on the paper feed tray and fed, there are problems such as non-feeding of envelopes and double feeding. There is an envelope sheet feeding device and an envelope sheet feed cassette configured so as not to occur (see, for example, Patent Document 1).

  Before describing the envelope sheet feeding device and the envelope sheet cassette disclosed in Patent Document 1, the envelope (Japanese envelope) fed here will be briefly described with reference to FIGS. 1 and 2.

  As shown in FIGS. 1A and 1B, generally, in a rectangular envelope (Japanese envelope) F enclosing a letter or the like, a cover sheet Fa and a backing sheet Fb are overlapped to form a bag shape. In addition, since the bottom Ft side opposite to the flap Ff side formed on the front end side of the envelope F is glued to the backing paper Fb by the adhesive margin Fn, the thickness on the bottom Ft side is equivalent to three sheets of paper, and the bottom Ft side Becomes thicker than the flap portion Ff side of one sheet of paper.

  Accordingly, as shown in FIG. 2, when a rectangular envelope F is printed using a printing apparatus (not shown), a cover is usually used to print the address and address on the cover Fa of the envelope F. The paper is stacked on the paper feed tray K with the Fa side facing up and the back paper Fb side facing down.

  In this case, since the bottom portion Ft side of the envelope F is more rigid than the flap portion Ff side, the bottom portion Ft side of the envelope F is set to the top in the paper feeding direction and is fed. The flap portion Ff side is opened without being folded and is directed to the side opposite to the paper feeding direction.

  At this time, when a plurality of envelopes F are stacked on the sheet feed table K in a normal posture with the bottom Ft side of the envelope F set to the downstream side (leading side) in the sheet feeding direction, the uppermost layer from the sheet feed table K is placed. The height H1 on the bottom Ft side of the envelope F on the paper feed side is significantly higher than the height H2 on the flap Ff side opposite to the paper feed side. For this reason, upward warping (up curl) occurs on the bottom Ft side of the envelope F, which causes problems such as non-feeding and double feeding of the envelope.

  Therefore, although not shown here, in the envelope feeder disclosed in Patent Document 1, when the envelope is loaded on the sheet feed table with the bottom side of the envelope set to the top in the feeding direction, In order to lift and support the flap side of the envelope opposite to the paper direction, an inclined table having an inclined stacking surface inclined by a predetermined angle with respect to the upper surface of the paper supply table is provided at a rear portion of the paper supply table. Or a tilting table with a variable tilt angle is rotatably installed at a rear portion of the paper feed table.

  In addition, in order to support the lower part of the envelope, which is the leading side in the paper feeding direction, at the front part on the paper feeding table, the loading table having shape restoration properties is inclined to start the tilting table or the tilting table. It is installed on the paper feed tray according to the height.

  When the envelopes loaded on the loading platform are full, the loading surface of the loading platform is inclined downward from the upstream side to the downstream side in the paper feeding direction, and the number of envelopes is not fully loaded. As the number decreases, the loading surface of the loading table gradually returns to the substantially flat loading surface position.

  Further, on the bottom side of the envelope, above the sheet feed table, a call roller for feeding the uppermost envelope among a plurality of envelopes stacked on the sheet feed table (hereinafter referred to as a sheet feed roller). And a separation roller pair for separating the envelopes one by one downstream from the paper feed roller.

  Therefore, when the envelope feeding device is configured as described above, the uppermost envelope stacked on the stacking base is the bottom side of the envelope, which is the leading side in the feeding direction, and the side opposite to the feeding direction. Since the flap part side can be in a posture (horizontal posture) substantially parallel to the top surface of the paper feed tray, when the uppermost envelope is fed by the paper feed roller, the envelope is not fed or double fed. It is stated that there is no problem such as.

  On the other hand, the envelope paper feed cassette disclosed in Patent Document 1 is detachably installed on the paper feed stand. In this envelope sheet feeding cassette, an inclined table for pivoting upward and supporting the flap side of the envelope is installed at a rear portion of the envelope sheet feeding table mounted on the sheet feeding table. In addition, a loading table having a shape restoring property is installed at a front portion of the envelope sheet feeding table in order to support the envelope by lowering the bottom side of the envelope downward. In addition, a pressure lever is swingably provided at a front portion of the envelope feeding table and ahead of the stacking table.

  At this time, in the above-described pressure lever, the biasing force of the torsion coil spring is set to a low load, so that the paper feed roller comes into contact with the uppermost envelope with a paper feed pressure within an appropriate range. The pressurizing lever is inclined downward from the upstream side to the downstream side in the paper feeding direction when the envelopes stacked on the envelope paper feed stand are full, and the number of envelopes decreases from the full state. Accordingly, it is configured to return to a substantially flat loading surface position.

  Therefore, when the envelope sheet feed cassette is configured as described above, the envelope sheet feed cassette is detachable on the sheet feed table, and the uppermost envelope loaded on the envelope sheet feed table is the envelope. It is described that since it can take a posture (horizontal posture) substantially parallel to the upper surface of the paper feed table, it can obtain substantially the same effect as the above-described envelope paper feeder.

JP 10-35901 A

  By the way, according to the envelope sheet feeding device and the envelope sheet tray disclosed in Patent Document 1, when the bottom of the envelope is set to the top in the sheet feeding direction on the stacking table or the envelope sheet tray, the sheets are stacked. Since the uppermost envelope can take a posture (horizontal posture) substantially parallel to the upper surface of the paper feed table, it is possible to take measures against problems such as non-feeding and double feeding of the envelope.

  On the other hand, recently, since a large amount of printing is desired for the printing apparatus, about 4000 sheets of A3 size or A4 size can be stacked on the sheet feeding table, and a large number of envelopes can be stacked. Development of such a paper feeding device is required.

  Therefore, in newly developing the paper feeding device, a part of the technical idea of the envelope paper feeding device and the envelope paper feed cassette disclosed in the above-mentioned Patent Document 1 is applied. An inclination table for lifting and supporting the flap side of the envelope is rotatably installed at the rear part of the paper feed table, and a loading table and an additional unit for supporting the bottom side of the envelope to be lowered downward. When at least one of the pressure levers is installed at the front part of the paper feed table, there is a possibility that problems such as non-feeding or double feeding of paper and envelopes may occur.

  In other words, when a large number of sheets are stacked on the paper feed tray, it becomes flat by tilting the tilting table on the paper feed tray on the rear end side of the paper, but on the front end side of the paper, Since at least one of the loading platform and the pressure lever pivots downward depending on the weight, the leading edge of the uppermost sheet is bent downward, so that the sheet feeding roller normally feeds. I can't.

  In addition, when a large number of sheets or envelopes are stacked on the paper feed tray, if the biasing force of the torsion coil spring for biasing the pressure lever is weak, the weight of the large number of sheets and envelopes will increase. The biasing force of the torsion coil spring cannot give an optimum sheet feeding pressure to the sheet feeding roller.

  In addition, when the biasing force of the torsion coil spring for biasing the pressure lever is weak, the rigidity of the paper and envelope varies depending on the thickness and material. The optimum paper feed pressure cannot be applied.

  Therefore, the present invention can be applied to a printing apparatus capable of printing an image on a sheet or an envelope. A large number of sheets or envelopes are stacked on a sheet feeding table, and the uppermost sheet or envelope is fed by a sheet feeding roller. When feeding paper, it is possible to reliably feed paper, and when feeding envelopes, the bottom side opposite to the flap formed on the front side of the envelope is the downstream side (leading side) of the feeding direction. When a large number of sheets are stacked on the sheet feeding table, the loaded uppermost envelope can take a posture (horizontal posture) substantially parallel to the upper surface of the sheet feeding table, and when feeding envelopes An object of the present invention is to provide a sheet feeding device capable of applying an optimum sheet feeding pressure to a sheet feeding roller.

The present invention has been made in view of the above problems, and the invention according to claim 1 is capable of stacking a large number of sheets of either paper or envelopes on the upper surface of a paper feed tray. In the envelope, the bottom side, which is thicker than the thin flap side, is set to the downstream side in the paper feeding direction, and the uppermost stacked paper or the envelope is fed by the paper feeding roller. In the paper feeder
It is movably provided on the upstream side of the paper feed direction of the paper feed tray. When stacking the paper, the front surface is stored at substantially the same height as the upper surface of the paper feed tray, while the envelope is loaded. In this case, a first movable plate that is inclined upward from the upper surface of the paper feed table so as to lift and support the flap side of the envelope.
The feed table of the sheet feeding direction downstream side turnably provided, the upper surface in the case of stacking the paper is locked substantially at the same height as the upper surface of the feeding table, whereas, the envelope A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
A cam plate fixed to a shaft rotatable in a first movable plate housing portion formed on the upstream side in the paper feed direction of the paper feed table and contacting and separating from a rear surface of the first movable plate;
A switching operation lever fixed to the shaft extending from one side of the sheet feed base to the side of the first movable plate storage unit,
In the sheet feeding device, an inclination angle of the first movable plate is varied depending on a rotation angle of the cam plate when the switching operation lever is operated .

In the invention according to claim 2, it is possible to stack a large number of sheets or one of envelopes on the upper surface of the sheet feed table, and in the case of the envelope, the flap portion side where the thickness is thin among the envelopes In a sheet feeding device that sets and stacks the bottom side that is thicker on the downstream side in the sheet feeding direction, and feeds the stacked uppermost sheet or envelope by a sheet feeding roller,
It is movably provided on the upstream side of the paper feed direction of the paper feed tray. When stacking the paper, the front surface is stored at substantially the same height as the upper surface of the paper feed tray, while the envelope is loaded. In this case, a first movable plate that is inclined upward from the upper surface of the paper feed table so as to lift and support the flap side of the envelope.
The sheet feeding table is rotatably provided on the downstream side in the sheet feeding direction. When stacking the sheets, the upper surface is locked at substantially the same height as the upper surface of the sheet feeding table. A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
A locking lever provided rotatably on the lower surface side of the second movable plate while being biased by a torsion spring in the inclination direction of the second movable plate;
A first slide slides between a downstream side in the paper feeding direction and an upstream side opposite to the downstream side along one side surface of the paper feed table, and a locking pin is fixed to the downstream side. A slide plate,
A spring latching portion formed on the downstream side so as to be opposed to a spring latching portion formed on the second movable plate, a first slide plate pressing portion formed on the upstream side, and the downstream side And a switching operation knob fixed between the upstream side and the upstream side, and slides between the downstream side in the paper feeding direction and the upstream side opposite to the downstream side along the first slide plate. A second slide plate that
A tension spring latched between a spring latching portion of the second movable plate and a spring latching portion of the second slide plate,
When the switching operation knob is operated to move both the first and second slide plates to the downstream side when the paper is loaded, the second lever is engaged by locking the locking lever via the locking pin. The plate is locked, and on the other hand, when the envelope is loaded, the switching operation knob is operated to move the first and second slide plates to the upstream side by a first predetermined amount from the time of locking to the locking lever. The first lever is applied to the tension spring by releasing the locking to the second movable plate by the locking lever, and the second slide plate is operated by operating the switching operation knob. Only when the first slide plate is moved to the upstream side by a second movement amount larger than the first movement amount, the first slide plate moved by the first predetermined amount is locked to the second movable plate. The second larger than the first urging force is applied to the tension spring while releasing A sheet feeding apparatus characterized by imparting force.

In the invention according to claim 3, it is possible to stack a large number of sheets or one of envelopes on the upper surface of the paper feed table, and in the case of the envelope, the flap portion side where the thickness is thin in the envelope In a sheet feeding device that sets and stacks the bottom side that is thicker on the downstream side in the sheet feeding direction, and feeds the stacked uppermost sheet or envelope by a sheet feeding roller,
The envelope is movably provided on the upstream side in the sheet feeding direction of the sheet feeding table. When stacking the sheets, the front surface takes a first posture substantially the same as the upper surface of the sheet feeding table, while the envelope A first movable plate that takes a second posture inclined upward from the upper surface of the paper feed base so as to lift and support the flap portion side of the envelope upward,
The secured to feed table of the sheet feeding direction of the first movable plate receiving portion in rotatable shaft formed on the upstream side, and the cam plate toward or away on a rear surface of the first movable plate, and the second A switching operation lever fixed to the shaft extending from one movable plate housing portion to one side surface of the paper feed base, and according to the rotation of the cam plate when the switching operation lever is operated First movable plate moving means for moving the first movable plate so as to be able to take the first posture and the second posture;
The sheet feeding table is rotatably provided on the downstream side in the sheet feeding direction. When stacking the sheets, the upper surface is locked at substantially the same height as the upper surface of the sheet feeding table. A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
Has a lower surface opposite to the engaging lever rotatably provided in the second movable plate in the feeding table of the paper feed direction of the lower flow side, in response to said rotation of said locking lever first A second movable plate locking and unlocking means for locking the movable plate at the time of loading the paper while releasing the lock to the second movable plate at the time of loading the envelope;
A sheet feeding device comprising:

According to a fourth aspect of the present invention, in the paper feeding device according to the third aspect,
The second movable plate locking and unlocking means are:
The locking lever provided rotatably on the lower surface side of the second movable plate while being urged in the tilt direction of the second movable plate by a torsion spring;
A first slide plate that slides between a downstream side in the paper feeding direction and an upstream side opposite to the downstream side along one side surface of the paper feed table;
The first slide plate is fixed to the downstream side of the first slide plate, and when the first slide plate moves to the downstream side, the first movable plate is engaged with the locking lever to lock the second movable plate. A locking pin that releases the locking of the locking lever as the slide plate moves to the upstream side;
A spring latching portion formed on the downstream side so as to be opposed to a spring latching portion formed on the second movable plate, a first slide plate pressing portion formed on the upstream side, and the downstream side And a switching operation knob fixed between the upstream side and the upstream side, and slides between the downstream side in the paper feeding direction and the upstream side opposite to the downstream side along the first slide plate. A second slide plate that
A tension spring latched between a spring latching portion of the second movable plate and a spring latching portion of the second slide plate ,
When the switching operation knob is operated and the second slide plate is moved to the downstream side when the paper is loaded, the first slide plate is moved to the downstream side by the first slide plate pressing portion and the locking is performed. The locking lever is locked via a pin to lock the second movable plate. On the other hand, when the envelope is loaded, the switching operation knob is operated to move the second slide plate to the upstream side. Along with this, the first slide plate is moved to the upstream side to release the locking to the second movable plate by the locking lever, and the second movable plate is moved below the upper surface of the paper feed table. A sheet feeding device characterized in that the sheet feeding device can be inclined toward the front .

Further, the invention according to claim 5 is the sheet feeding device according to claim 4 , wherein
A first mode in which the first and second slide plates are both moved to the downstream side, and the second movable plate is locked at substantially the same height as the upper surface of the sheet feed table via the locking lever. When,
Along with the operation of moving the second slide plate to the upstream side by the first movement amount relative to the first mode, the first slide plate is moved to the upstream side by the first movement amount. The second movable plate is unlocked and the spring latching portion of the second movable plate and the spring latching portion of the second slide plate are separated by a first predetermined amount, A second mode for applying a first biasing force to the tension spring;
With the operation of moving the second slide plate to the upstream side by a second movement amount larger than the first movement amount with respect to the first mode, the first slide plate is moved to the upstream side. The second movable plate is released by being moved by the first movement amount, and the second movable plate and the second slide plate are latched between the spring latching portion and the spring latching portion of the second slide plate. A third mode in which a second biasing force larger than the first biasing force is applied to the tension spring by being separated by a second predetermined amount larger than a predetermined amount of 1,
Sheet feeding apparatus according to claim Toridoku Rukoto a.

According to the paper feeding device according to claim 1, a large number of sheets or envelopes are stacked on the paper feed table, and in the case of envelopes, the thickness is smaller than the thickness of the thin flap portion of the envelopes. When the paper feeding device is configured to stack with the thick bottom side set to the downstream side (top side) in the paper feeding direction, when feeding paper, the first and second movable plates are fed. By making the top of the table approximately the same height as the top surface, the top layer paper takes a posture parallel to the top surface of the paper feed table from the leading edge to the trailing edge, thus suppressing paper misfeeds such as non-feed and double feed. it can.
At this time, since the inclination angle of the first movable plate is varied according to the rotation angle of the cam plate when the switching operation lever is operated, the user can set the switching operation lever according to the length of the envelope and the loading amount of the envelope. The tilt angle of the first movable plate can be set by manipulating the rotation angle.

  When feeding envelopes, the first movable plate provided upstream of the sheet feed direction in the sheet feed direction is supported by lifting the flap side of the envelope upward, while the sheet feed direction of the sheet feed table The bottom side of the envelope is supported downward by the second movable plate provided on the downstream side of the envelope, so that the bottom side of the envelope, which is the head of the envelope feeding direction, is opposite to the feeding direction. Even if the thickness is different on the flap side, the uppermost envelope stacked on the paper feed tray can take a posture that is substantially parallel to the top surface of the paper feed tray. Paper feeding errors can be suppressed.

Further, according to the paper feeding device of claim 2, a large number of sheets or envelopes are stacked on the paper feed table, and particularly in the case of envelopes, the envelope part is thinner than the thin flap part side. When the paper feeding device is configured to stack with the thick bottom side set to the downstream side (leading side) in the paper feeding direction, when feeding paper, the first and second movable plates are By making the height almost the same as the top surface of the paper feed tray, the top layer paper takes a posture parallel to the top surface of the paper feed tray from the leading edge to the rear edge. Can be suppressed.
When feeding envelopes, the first movable plate provided upstream of the sheet feed direction in the sheet feed direction is supported by lifting the flap side of the envelope upward, while the sheet feed direction of the sheet feed table The bottom side of the envelope is supported downward by the second movable plate provided on the downstream side of the envelope, so that the bottom side of the envelope, which is the head of the envelope feeding direction, is opposite to the feeding direction. Even if the thickness is different on the flap side, the uppermost envelope stacked on the paper feed tray can take a posture that is substantially parallel to the top surface of the paper feed tray. Paper feeding errors can be suppressed.
At this time, when an envelope having a light weight is stacked on the paper feed table, the spring hooking portion of the second movable plate and the spring hooking portion of the second slide plate are separated by a first predetermined amount. Since the first biasing force can be applied to the tension spring, the first biasing force by the tension spring is set so that the repulsive force to the paper feed roller is optimized corresponding to the light weight of the envelope. Can do.
On the other hand, when an envelope having a heavy weight is stacked on the sheet feed table, the gap between the spring latching portion of the second movable plate and the spring latching portion of the second slide plate is larger than the first predetermined amount. Since the second urging force can be applied to the tension spring by separating by a predetermined amount of 2, the second urging force by the tension spring corresponds to the repulsive force to the paper feed roller corresponding to the heavy weight of the envelope. It can be set to be optimal.

Further, according to the paper feeding device of claim 3, a large number of sheets or envelopes are stacked on the paper feed stand, and particularly in the case of envelopes, the envelope part is thinner than the thin flap part side. When the paper feeding device is configured to stack with the thick bottom side set to the downstream side (leading side) in the paper feeding direction, when feeding paper, the first and second movable plates are By making the height almost the same as the top surface of the paper feed tray, the top layer paper takes a posture parallel to the top surface of the paper feed tray from the leading edge to the rear edge. Can be suppressed.
When feeding envelopes, the first movable plate provided upstream of the sheet feed direction in the sheet feed direction is supported by lifting the flap side of the envelope upward, while the sheet feed direction of the sheet feed table The bottom side of the envelope is supported downward by the second movable plate provided on the downstream side of the envelope, so that the bottom side of the envelope, which is the head of the envelope feeding direction, is opposite to the feeding direction. Even if the thickness is different on the flap side, the uppermost envelope stacked on the paper feed tray can take a posture that is substantially parallel to the top surface of the paper feed tray. Paper feeding errors can be suppressed.
At this time, the first movable plate moving means is fixed to a shaft that can be rotated in the first movable plate storage portion formed on the upstream side in the sheet feeding direction of the sheet feed table, and is in contact with the rear surface of the first movable plate. And a switching operation lever fixed to a shaft extending from the inside of the first movable plate storage portion to one side surface of the sheet feed table, and the cam plate when the switching operation lever is operated. Since the first movable plate is moved so as to be able to take the first posture and the second posture according to the rotation, the structure of the first movable plate moving means is simple.
On the other hand, the second movable plate locking and unlocking means has a lower surface opposed to the engaging lever rotatably provided in the second movable plate in the paper feeding table of the paper feeding direction of the lower flow side , while locking the second movable plate in response to rotation of the locking lever during the loading of the paper, since releasing the engagement of the second movable plate when loading envelopes, engagement of the second movable plate Stopping and unlocking can be easily performed by the locking lever.

According to the paper feeding device of claim 4 , the second movable plate locking and unlocking means for locking the second movable plate when stacking sheets, and releasing the lock when stacking envelopes, When the second slide plate is moved to the downstream side by operating the switching operation knob when loading paper, the first slide plate is moved to the downstream side by the first slide plate pressing portion, and the lock lever via the lock pin To lock the second movable plate, while moving the second slide plate to the upstream side by operating the switching operation knob when the envelope is loaded, the first slide plate is moved to the upstream side Thus, the latch to the second movable plate by the latch lever is released so that the second movable plate can be tilted downward from the upper surface of the paper feed table. The leading edge of the paper feeding direction can be stacked in parallel with the upper surface of the paper feed tray with the second movable plate.
On the other hand, when the envelopes are stacked on the sheet feed table, the bottom side of the uppermost envelope is moved to the bottom of the sheet feed table by lowering the thick bottom part at the top in the sheet feeding direction with the second movable plate. It can take a posture substantially parallel to the top surface.

Further, according to the paper feeding device of the fifth aspect, when the first mode is obtained when the sheets are stacked on the paper feeding table, the second movable plate has a height substantially the same as the upper surface of the paper feeding table. Since the front end of the stacked paper in the paper feeding direction is held in parallel with the upper surface of the paper feed table, the paper can be reliably fed.

  In addition, when an envelope having a light weight is stacked on the paper feed table, the gap between the spring latching portion of the second movable plate and the spring latching portion of the second slide plate is obtained when the second mode is obtained. Since the first urging force can be applied to the tension spring by separating the first predetermined amount, the repulsive force to the paper feed roller can be adjusted to the light weight of the envelope by the first urging force by the tension spring. Can be set to be optimal.

  Further, when a heavy envelope is stacked on the paper feed table, when the third mode is obtained, the gap between the spring latching portion of the second movable plate and the spring latching portion of the second slide plate Since the second urging force can be applied to the tension spring by separating the second predetermined amount larger than the first predetermined amount, the second urging force by the tension spring repels the paper feeding roller. The force can be set to be optimal for the heavy weight of the envelope.

(A), (b) is the back view and side view which showed the rectangular envelope. FIG. 6 is a side view showing a state in which a plurality of envelopes are stacked on a sheet feeding table in a normal posture with the bottom side of the envelope set as the head in the sheet feeding direction. It is the perspective view shown in order to demonstrate the whole structure of the paper feeder which concerns on this invention. FIG. 6 is a perspective view illustrating a state in which sheets are stacked on a sheet feeding table in the sheet feeding device according to the present invention. FIG. 5 is a perspective view illustrating a state in which envelopes are stacked on a sheet feeding table in the sheet feeding device according to the present invention. FIG. 6 is a perspective view for explaining an envelope flap portion supporting means for supporting the flap portion side of the envelope loaded on the sheet feed table in the paper feeding device according to the present invention. (A), (b) is a side view for demonstrating operation | movement of the envelope flap part support means shown in FIG. FIG. 5 is a perspective view of an envelope bottom portion supporting means for supporting the bottom side of envelopes stacked on a sheet feed stand as viewed from the right side surface side of the sheet feed stand in the sheet feeding device according to the present invention. FIG. 6 is a perspective view of an envelope bottom portion supporting unit that supports a bottom side of an envelope stacked on a sheet feed stand as viewed from the left side of the sheet feed stand in the sheet feeding device according to the present invention. It is the side view which expanded and showed the relationship between the 2nd movable plate shown in FIG.8 and FIG.9, a latching lever, and a 1st, 2nd slide plate. (A), (b), (c), (d) is the top view, front view, side view, and bottom view which showed the 1st slide board shown in FIGS. 8-10. (A), (b), (c), (d) is the top view, front view, side view, and bottom view which showed the 2nd slide board shown in FIGS. 8-10. (A)-(c) is the top view and side view shown, respectively, in order to demonstrate operation | movement of the envelope bottom part support means shown in FIG.8 and FIG.9.

  Hereinafter, an embodiment of a paper feeding device according to the present invention will be described in detail with reference to FIGS.

  FIG. 3 is a perspective view showing the overall configuration of the sheet feeding device according to the embodiment of the present invention.

  As shown in FIG. 3, a paper feeder 10 according to an embodiment of the present invention includes an inkjet printing apparatus capable of printing (forming) images and characters on a paper P indicated by a two-dot chain line and an envelope F indicated by a solid line. The present invention is applied to a printing apparatus (image forming apparatus) 1 such as a stencil printing apparatus, a laser beam printer, and a thermal transfer printing apparatus.

  Further, the above-described paper feeding device 10 can stack either the paper P or the envelope F on the upper surface 11 a of the paper feeding table 11. The paper feed tray 11 is installed on the outside of one side plate 2 of the printing apparatus 1 with the paper P or the envelope F stacked thereon so as to be able to move up and down via the lifting means 20.

  The above-described paper feed tray 11 is rigid so that, for example, about 4000 sheets of one type of paper P such as A3 size, A4 size, B4 size, and B5 size having different outer sizes can be stacked, and a large number of envelopes F can be stacked. It is formed in a substantially rectangular shape using a certain metal material or resin material.

  At this time, the downstream side in the paper feeding direction of the paper P or the envelope F (the front side in the paper feeding direction) is made to correspond to the front part of the paper feeding table 11, and the downstream side in the paper feeding direction (the front side in the paper feeding direction) In the following, the opposite upstream side (the rear side in the paper feeding direction) is made to correspond to the rear part of the paper feed table 11.

  In addition, rectangular holes 11b and 11c are formed on the left and right of the front portion of the paper feed tray 11 so as to penetrate in the vertical direction, and the width direction of the paper P or the envelope F is set in the rectangular holes 11b and 11c. A pair of left and right guide fences 12L and 12R to be guided enter. The width direction of the paper P or the envelope F is a direction orthogonal to the paper feeding direction.

  The pair of left and right guide fences 12L and 12R described above are formed long in the height direction. Then, the upper and lower end portions of the pair of left and right guide fences 12L and 12R are fitted to the guide shafts 13 that are provided in parallel and spaced apart from each other in the vertical direction perpendicular to the sheet feeding direction. The pair of left and right guide fences 12L and 12R are movable in the width direction of the paper P or envelope F along the guide shafts 13 manually.

  In addition, a paper feed roller 14 and a separating roller 15 are pivotally supported by a pair of left and right arms 16 above the paper feed tray 11, and both the rollers 14 and 15 are counterclockwise by a roller rotation drive source 18, respectively. It can be rotated. At this time, the upper portion of one side plate 2 of the printing apparatus 1 is opened wide so that the maximum size paper P fed by both rollers 14 and 15 can pass through.

  The paper feed roller 14 arranged on the upstream side in the paper feed direction (conveyance direction) of the paper P or envelope F is applied to the uppermost paper P or envelope F loaded on the paper feed tray 11 while rotating. The paper is fed in contact.

  On the other hand, a friction plate 17 is in contact with the separating roller 15 disposed on the downstream side of the sheet feeding roller 14, and the sheet P or envelope F fed from the sheet feeding roller 14 is separated from the separating roller 15 and the friction plate 17. The sheets are separated one by one while being nipped and conveyed between them to prevent double feeding, and then conveyed into the printing apparatus 1.

  In addition, the lifting means 20 for lifting the sheet feeding table 11 includes a pair of left and right rack members 21 </ b> L and 21 </ b> R that are vertically parallel to each other in the vertical direction with a distance between the left and right sides of one side plate 2 of the printing apparatus 1. It is attached. The pair of left and right rack members 21 </ b> L and 21 </ b> R are formed with long rack teeth 21 a symmetrically toward the rear side of the paper feed table 11.

  On the other hand, a pair of left and right side plates 22L, 22R formed in a substantially mountain shape are attached to the front portions of the left and right side surfaces 11e, 11f of the paper feed tray 11.

  An L-shaped motor bracket 23 is fixed to the outside of the left side plate 22 </ b> L, and a motor 24 with an encoder is attached to the horizontal surface of the motor bracket 23. A final stage pinion gear (not shown) of the gear box 25 attached to the shaft of the motor 24 with the encoder is pivotally supported on the vertical surface of the motor bracket 23, and further, the final stage pinion gear (not shown). Meshes with the rack teeth 21a of the left rack member 21L.

  On the other hand, a flat plate 26 is fixed to the outside of the right side plate 22R. A pinion gear 27 is pivotally supported on the plate 26, and the pinion gear 27 meshes with the rack teeth 21a of the right rack member 21R. doing.

  With the above-described configuration of the lifting / lowering means 20, the sheet feeding table 11 can be moved up and down substantially horizontally without tilting left and right, and the uppermost sheet P or envelope F stacked on the sheet feeding table 11 is provided. The paper feed table 11 is raised to the paper feed position that contacts the paper feed roller 14.

  In this embodiment, the sheet feeding table 11 is moved up and down by the lifting / lowering means 20, but the sheet feeding table 11 is moved outside or inside the one side plate 2 of the printing apparatus 1 without providing the lifting / lowering means 20. In this case, the paper feed roller 14 may be swung so as to be in contact with the uppermost sheet P or envelope F via a swing arm or the like.

  When stacking the sheets P, the leading end side of the sheets P is set to the top in the sheet feeding direction and is stacked on the sheet feeding table 11.

  On the other hand, when the envelopes F are stacked, they are stacked on the paper feed tray K with the front cover Fa side of the envelopes F facing up and the back paper Fb facing down. At this time, as described above Since the bottom portion Ft of the envelope F is more rigid than the flap portion Ff, the bottom portion Ft side of the envelope F is set to the downstream side (leading side) in the paper feeding direction, and is fed. The flap portion Ff side is opened without being folded and is directed to the side opposite to the paper feeding direction.

  At this time, as described above with reference to FIG. 2, the bottom Ft side of the envelope F is set to the top in the sheet feeding direction, and the envelope F is placed on the sheet feeding table K (= sheet feeding table 11) in a normal posture. When a plurality of sheets are stacked, the stacking height from the sheet feed tray K to the uppermost envelope F is such that the height H1 on the bottom Ft side of the envelope F serving as the sheet feeding side is higher than the height H2 on the flap section Ff side. Remarkably higher.

  Therefore, in this embodiment, with respect to the uppermost envelope F stacked on the paper feed tray 11, the bottom Ft side of the envelope F which is the leading side in the paper feeding direction and the flap which is opposite to the paper feeding direction. Envelope flap part support that supports the flap part Ff side of the envelope F on the rear part of the sheet feed table 11 so that the Ff side can take a posture (horizontal posture) substantially parallel to the upper surface 11 a of the sheet feed table 11. The means 30 is installed, and the envelope bottom support means 40 for supporting the bottom Ft side of the envelope F is installed at the front portion of the paper feed tray 11. Both means 30, 40 will be described in detail later.

  Here, the case where the paper P is stacked on the paper feed tray 11 and the case where the envelope F is stacked on the paper feed tray 11 will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a perspective view showing a state in which the sheets P are stacked on the paper feed tray 11, while FIG. 5 is a perspective view showing a state in which the envelopes F are stacked on the paper feed tray 11.

  First, as shown in FIGS. 4 and 5, the paper feed table 11 has a flat upper surface 11 a and is provided on the inner left and right sides of the pair of left and right side plates 22 </ b> L and 22 </ b> R on the front portion side of the paper feed table 11. An upper surface 11a between the rectangular holes 11b and 11c is formed narrow.

  In addition, an envelope flap portion supporting means 30 for supporting the flap portion Ff side of the envelope F is formed at a rear portion on the upper surface 11a of the sheet feed tray 11 (upstream in the sheet feeding direction of the sheet feed tray 11). A first movable plate (envelope flap portion support movable plate) 31 is rotatably supported in a first movable plate storage portion 11 d formed at a rear portion of the paper feed tray 11.

  Thereby, the 1st movable plate 31 is accommodated so that opening and closing with respect to the 1st movable plate accommodating part 11d is possible.

  At this time, the first movable plate storage portion 11d formed in the rear portion of the paper feed tray 11 is provided with a rectangular hole on the upper surface 11a of the paper feed tray 11 in which the first movable plate 31 can be accommodated, or A storage case may be attached to the rear part of the paper feed tray 11.

  In this embodiment, the first movable plate 31 is rotatably provided in the first movable plate storage portion 11d. However, the present invention is not limited to this, and the first movable plate 31 is the first movable plate. The structure which moves up and down with respect to the accommodating part 11d may be sufficient.

  Further, an envelope bottom support means 40 for supporting the bottom Ft of the envelope F is formed in front of the front end 11g in the paper feed direction of the paper feed tray 11 (downstream in the paper feed direction of the paper feed tray 11). The second movable plate (envelope bottom support movable plate) 41 is formed to be long in a direction orthogonal to the paper feed direction, and is rotated between the upper surface 11a of the paper feed table 11 and a portion below the upper surface 11a. It is supported movably.

  As shown in FIG. 4, when the sheets P are stacked on the upper surface 11 a of the paper feed tray 11, the first movable plate 31 that is rotatably installed at the rear portion of the paper feed tray 11 has the front surface 31 a. It is closed so as to maintain substantially the same height as the upper surface 11a of the paper feed tray 11, and is stored in the first movable plate storage portion 11d.

  In addition, the second movable plate 41 rotatably installed in the front portion of the paper feed table 11 has a top surface 41a via a locking lever 45 (FIGS. 8 to 10 and FIG. 13) to be described later. The upper surface 11a is locked at a substantially same height.

  From the above, when the paper P is loaded, the first and second movable plates 31 and 41 do not rotate, but are flattened while maintaining substantially the same height as the upper surface 11a of the paper feed base 11. P can be loaded on the upper surface 11a.

  On the other hand, as shown in FIG. 5, when the envelope F is stacked on the upper surface 11a of the paper feed tray 11, the envelope F is placed with the cover Fa of the envelope F facing up and the back paper Fb facing down. The sheets are stacked on the upper surface 11a between the rectangular holes 11b and 11c provided on the left and right of the front portion of the sheet feed table 11, and the bottom Ft side of the envelope F is directed in the sheet feeding direction.

  In addition, the first movable plate 31 housed in the first movable plate housing portion 11d of the paper feed tray 11 is opened upward via a switching operation lever 36 described later, and the upper surface 11a of the paper feed tray 11 is opened. Inclined by a predetermined angle, the end of the flap portion Ff side of the envelope F is brought into contact with the front surface 31a of the first movable plate 31, and the flap portion Ff side of the envelope F is lifted upward by the first movable plate 31. I support it.

  Further, the second movable plate 41 installed in front of the front end portion 11g of the paper feed base 11 in order to support the lower portion Fe of the envelope F downward is fed via a switching operation knob 51 described later. The base 11 is rotated downward from the upper surface 11a.

  From the above, when the envelope F is loaded, the first movable plate 31 rotates and inclines upward from the upper surface 11 a of the paper feed table 11, while the second movable plate 41 is arranged on the paper feed table 11. Since the uppermost envelope F is rotated and tilted downward from the upper surface 11a, the stacked uppermost envelope F can take a posture (horizontal posture) substantially parallel to the upper surface 11a of the paper feed tray 11.

  Next, the envelope flap part support means 30 which has the 1st movable plate (envelope flap part support movable plate) 31 which comprises a part of principal part of this invention is demonstrated using FIG.6 and FIG.7.

  FIG. 6 is a perspective view showing the configuration of the envelope flap portion support means.

  As shown in FIG. 6, in the envelope flap portion support means 30 described above, the first movable plate 31 that is inclined only when the envelope F is loaded is composed of the flat front surface 31 a, the rear surface 31 b, and the lower shaft support portion. 31c and left and right side surfaces 31d and 31e are formed into a rectangular shape using a sheet metal material.

  The shaft support portion 31c of the first movable plate 31 is pivotally supported by the first shaft 32 fixed to the left and right in the first movable plate storage portion 11d of the paper feed table 11, and the first The first movable plate 31 is urged in the closing direction by a torsion spring 33 fitted into the first shaft 32, and the front surface 31a can be opposed to the flap portion Ff side of the envelope F when the first movable plate 31 is opened. It has become.

  Further, in the first movable plate storage portion 11 d of the paper feed table, a long second shaft 34 is parallel to the first shaft 32 and the left side surface 11 d 1 in the first movable plate storage portion 11 d and the paper feed table 11. The second shaft 34 is pivotally supported between the right side surface 11f and the rear surface 31b of the first movable plate 31.

  Further, the above-described second shaft 34 includes a cam plate 35 having a plurality of convex portions 35 a and concave portions 35 b alternately formed at the tip thereof divided into two on the left and right sides in the first movable plate storage portion 11 d of the paper feed table 11. It is fixed.

  At this time, each dimension between the tips of the plurality of convex portions 35a and the bottoms of the plurality of concave portions 35b formed on the cam plate 35 and the second shaft 34 serving as the rotation center changes stepwise.

  Further, the second shaft 34 passes through escape holes 48b and 49b of first and second slide members 48 and 49 that are slidably provided from the inside of the first movable plate storage portion 11d of the paper feed tray 11 to the right side surface 11f. A switching operation lever 36 is fixed to the end of the second shaft 34. The switching operation lever 36 switches the tilt angle of the first movable plate 31 by switching the rotation angle of the cam plate 35.

  Further, in the first movable plate storage portion 11d of the paper feed tray 11, when the two cam plates 35 are rotated counterclockwise and the first movable plate 31 is closed, each cam plate 35 is retracted. A relief hole 11d2 is formed.

  In addition, on the rear surface 31b of the first movable plate 31, two engaged recesses 31b1 that engage any one of the protrusions 35a of each cam plate 35 are formed at two left and right intervals. The inclination angle of the first movable plate 31 can be changed stepwise depending on the position of any one convex portion 35 a of the cam plate 35.

  Here, in explaining the operation of the envelope flap portion support means 30 configured as described above, FIG. 7A shows a case where sheets P are stacked, while FIG. 7B shows a case where envelopes F are stacked. Shows the case.

  As shown in FIG. 7A, when the paper P is stacked on the paper feed tray 11, the user operates the switching operation lever 36 provided on the right side surface 11 f side of the paper feed tray 11 in the counterclockwise direction. Then, the switching operation lever 36 is moved to a position where an imaginary line connecting the tip of the switching operation lever 36 and the center of the second shaft 34 to which the switching operation lever 36 is fixed is substantially parallel to the upper surface 11a of the sheet feeding table 11. When rotated, the cam plate 35 fixed to the second shaft 34 in the first movable plate storage portion 11 d of the paper feed tray 11 also rotates counterclockwise and retracts from the rear surface 31 b of the first movable plate 31. .

  As a result, the first movable plate 31 is rotated counterclockwise about the first shaft 32 by the biasing force of the torsion spring 33 and stored in the first movable plate storage portion 11 d of the paper feed tray 11. Therefore, the front surface 31a of the first movable plate 31 and the upper surface 11a of the paper feed table 11 are flat at substantially the same height.

  Therefore, when the first movable plate 31 is closed, the rear end side of the paper P can be stacked on the first movable plate 31.

  Further, as shown in FIG. 7B, when the envelope F is stacked on the paper feed tray 11, when the user rotates the switching operation lever 36 from the position shown in FIG. The cam plate 35 fixed to the second shaft 34 in the first movable plate storage portion 11d of the paper feed table 11 also rotates clockwise, and the cam plate 35 faces the rear surface 31b of the first movable plate 31 upward. As a result, the first movable plate 31 rotates clockwise around the first shaft 32 against the urging force of the torsion spring 33.

  Then, when the user rotates the switching operation lever 36 clockwise by a desired angle, any one of the convex portions 35a formed on the cam plate 35 is an engaged concave portion formed on the rear surface 31b of the first movable plate 31. Since the first movable plate 31 is inclined by a predetermined angle with respect to the upper surface 11a of the paper feed table 11 because it is engaged with 31b1, the flap portion Ff side of a large number of envelopes F that are in contact with the front surface 31a. Is supported to lift upward.

  At this time, the inclination angle of the first movable plate 31 is selected stepwise by the user by operating the switching operation lever 36 according to the length of the envelope F and the loading amount of the envelope F. It is possible to set. For example, the projection 35 a having the longest dimension between the tip of the projection 35 a of the cam plate 35 and the second shaft 34 is engaged with the engaged recess 31 b 1 formed on the rear surface 31 b of the first movable plate 31. The inclination angle of the first movable plate 31 becomes maximum.

  When the inclination angle of the first movable plate 31 is set, the flap portion Ff side of the uppermost envelope F lifted upward by the front surface 31 a of the first movable plate 31 is in relation to the upper surface 11 a of the paper feed table 11. Ideally, the envelope F should be substantially horizontal. However, even if the flap portion Ff side of the uppermost envelope F is lifted further upward than the substantially horizontal state, no paper feed failure occurs at all, so the envelope F can be fed without any problem. .

  Still further, in this embodiment, convex portions 35 a and concave portions 35 b are alternately formed on the cam plate 35, and any one convex portion 35 a is engaged with the engaged concave portion 31 b 1 of the first movable plate 31. However, the present invention is not limited to this, and the cam plate 35 fixed to the second shaft 34 can contact and separate from the rear surface 31b of the first movable plate 31, and the cam plate when the switching operation lever 36 is operated. Any structure may be used as long as the inclination angle of the first movable plate 31 can be varied by the rotation angle of 35.

  Next, the envelope bottom part support means 40 which has the 2nd movable plate (envelope bottom part support movable plate) 41 which comprises a part of principal part of this invention is demonstrated using FIGS. 8-13.

  FIGS. 8 and 9 are perspective views as seen from the right side surface 11f side and the left side surface 11e side of the sheet feed base in order to explain the configuration of the envelope bottom portion support means 40. FIG.

  As shown in FIGS. 8 and 9, in the above-described envelope bottom support means 40, as described above, the second movable plate 41 that is inclined only when the envelope F is stacked is provided with a flat upper surface 41a and lower surface 41b, and the upper surface. 41a and the lower surface 41b are connected to the left and right sides and have left and right side surfaces 41c and 41d hanging downward, and are bent using a sheet metal material.

  At this time, the upper surface 41a and the lower surface 41b of the second movable plate 41 are formed so that the direction orthogonal to the sheet feeding direction is as long as the lateral width of the sheet feeding table 11, and the upper surface 41a and the lower surface 41b are fed. The width in the paper direction is narrow.

  Further, a friction member 42 using a thin rubber material or the like is attached to the central portion of the upper surface 41a of the second movable plate 41, and is opposed to the paper feed roller 14 (FIG. 3) installed thereabove. Therefore, a frictional force is applied to the lowermost sheet P or envelope F by the friction member 42.

  A pair of left and right shafts 43 and 43 are fixed to the outer sides of the left and right side surfaces 41c and 41d of the second movable plate 41, respectively, and each shaft 43 is a pair of left and right side plates 22L on the front portion side of the paper feed table 11. , 22R, the second movable plate 41 is supported so as to be able to rotate forward relative to the leading end portion 11g of the paper feed base 11 in the paper feed direction. At this time, the shaft 43 on the right side 41d side of the second movable plate 41 enters a clearance hole 48a provided near the tip of the first slide plate 48 described later.

  Further, spring latching portions 41c1 and 41d1 are formed so as to project upward from the left and right side surfaces 41c and 41d of the second movable plate 41 toward the rear portion side of the paper feed tray 11, and these spring latching portions 41c1 and 41c1 are formed. One end side of a pair of left and right tension springs 44, 44 is hooked on 41d1.

  Then, the other end side of the tension spring 44 hooked on the left side surface 41 c side of the second movable plate 41 is hooked by a spring hooking portion (not shown) formed on the left side surface 11 e side of the paper feed table 11. However, the other end side of the tension spring 44 hooked on the right side surface 41d side of the second movable plate 41 is hooked by a spring hooking portion 49a formed in the vicinity of the tip portion of the second slide plate 49 described later. ing.

At this time, tension spring 44, as described later, with which the second movable plate 41 to bias about the axis 43 in a counterclockwise direction, imparting a repulsive force to the feeding roller 14 (FIG. 3) doing.

  Further, below the lower surface 41b of the second movable plate 41, a locking lever 45 for locking the rotatable second movable plate 41 is rotatably provided.

  The locking lever 45 described above has a front surface 45a and a rear surface 45b, and left and right side surfaces 45c and 45d connected to the left and right of the front surface 45a and the rear surface 45, and is bent using a sheet metal material.

  Further, the locking lever 45 is formed in a long length with the length between the left and right side surfaces 45 c and 45 d being substantially the same as the length of the second movable plate 41. Then, a long single shaft 46 is passed through the lower portions of the left and right side surfaces 45c and 45d of the locking lever 45, and both ends of the shaft 46 are fitted with a torsion spring 47 fitted outside the right side surface 45d. It is pivotally supported by a pair of left and right side plates 22L and 22R on the front part side of the sheet feed table 11 so as to be rotatable.

  At this time, one end of the torsion spring 47 is hooked on a spring hooking portion 45d1 formed on the right side surface 45d of the locking lever 45, and the other end side is hooked on the right side surface 11f side of the paper feed tray 11. Thus, the locking lever 45 is urged counterclockwise about the shaft 46.

  Further, as shown in an enlarged view in FIG. 10, a locking pin 50 fixed to the back surface of the first slide plate 48 described later enters and engages the right side surface 45d of the locking lever 45. A joint recess 45d2 is formed.

  When the locking pin 50 is engaged in the engaged recess 45 d 2 formed on the right side surface 45 d of the locking lever 45, the locking lever 45 stands up against the urging force of the torsion spring 47 and engages. The upper end portion 45e of the stop lever 45 comes into contact with the lower surface 41b of the second movable plate 41 so that the upper surface 41a of the second movable plate 41 is locked with the upper surface 11a of the paper feed table 11 being substantially the same height. Therefore, it is possible to stack the leading end side of the paper P on the second movable plate 41.

  8 and 9 again, on the outside of the right side surface 11f of the paper feed table 11, the first and second slide plates 48 and 49 are located on the downstream side in the paper feed direction and on the upstream side opposite to the downstream side. In other words, the first and second slide plates 48 and 49 are slidably provided in the front-rear direction of the paper feed table 11.

  At this time, the first slide plate 48 arranged on the inner side slides along the right side surface 11 f of the paper feed table 11, while the second slide plate 49 arranged on the outer side moves along the first slide plate 48. To slide.

  As shown in FIGS. 11A to 11D, the first slide plate 48 described above is formed in a long shape by bending a top and bottom into a U-shape using a sheet metal material. The first slide plate 48 has a plurality of guide holes into which a plurality of guide pins provided on the right side surface 11f of the sheet feed table 11 are fitted along the sliding direction, the shaft 43, and the second shaft 34. In addition, a plurality of escape holes 48a to 48c into which a switching operation knob 51 (FIG. 12) described later can enter are formed so as to penetrate therethrough.

  In addition, a locking pin 50 for locking the locking lever 45 described above is fixed to the front end portion in the paper feeding direction on the back surface side of the first slide plate 48.

  On the other hand, as shown in FIGS. 12A to 12D, the second slide plate 49 is formed shorter than the first slide plate 48 by bending the upper and lower sides into a U shape using a sheet metal material. The second slide plate 49 has a plurality of guide holes into which a plurality of guide pins provided on the first slide plate 48 are fitted along the slide direction, and a clearance hole through which the second shaft 34 enters. 49b is formed to penetrate therethrough.

  Further, a spring hooking portion 49 a for hooking the tension spring 44 described above is formed at the front end portion of the second slide plate 49 in the paper feeding direction, and is formed on the right side surface 41 d of the second movable plate 41. It is formed so as to protrude upward toward the front part of the sheet feed table 11 so as to face the portion 41d1 with a gap therebetween.

  Further, a first slide plate pressing portion 49c for pressing the first slide plate 48 is formed at the rear end portion of the second slide plate 49 by bending at a right angle toward the back surface side.

  Here, in explaining the operation of the envelope bottom support means 40 configured as described above, FIG. 13A shows a case where the sheets P are stacked, and FIG. 13B shows a tension when the envelopes F are stacked. FIG. 13C shows a case where the urging force of the tension spring 44 is set large when the envelope F is loaded.

  13A to 13C, each top view schematically shows the sliding state of the first and second slide plates 48 and 49 as viewed from above, and each side view is the first view. 1, the rotation state of the 2nd movable plates 31 and 41 is seen and seen from the side.

  In the following description, the slide of the first and second slide plates 48 and 49 toward the downstream side in the paper feeding direction is referred to as the front slide, and the first and second slide plates 48 and 49 are fed. The slide toward the upstream side in the direction will be described as the rear slide.

  First, as shown in FIG. 13A, when the sheets P are stacked on the sheet feed table 11, the user fixes the sheet P to the second slide plate 49 slidably provided on the right side surface 11f side of the sheet feed table 11. By operating the switching operation knob 51 forward (arrow X1 direction side), the rear end portion 48d of the first slide plate 48 is moved by the first slide plate pressing portion 49c formed at the rear end portion of the second slide plate 49. When it is pushed and slid forward (arrow X1 direction side), the locking pin 50 fixed to the tip of the first slide plate 48 is engaged with the locking lever 45.

  As a result, the locking lever 45 stands up by rotating clockwise around the shaft 46 against the torsion spring 47, and the upper end 45e of the locking lever 45 is raised as described above with reference to FIG. Since it contacts the lower surface 41 b of the second movable plate 41, the upper surface 41 a of the second movable plate 41 is locked at substantially the same height as the upper surface 11 a of the paper feed table 11. In this state, the leading end side of the sheet P can be stacked on the second movable plate 41, and therefore the leading end side of the uppermost sheet P is held in parallel with the upper surface 11 a of the sheet feeding table 11. In addition, sheet feeding errors such as non-feeding and double feeding of the paper P can be suppressed.

  At this time, the shaft 43 of the second movable plate 41 reaches the left end in the escape hole 48 a provided near the tip of the first slide plate 48.

  Needless to say, when the sheets P are stacked, the first movable plate 31 that is rotatably provided at the rear portion of the sheet feed table 11 is the upper surface 11a of the sheet feed table 11 as described above with reference to FIG. Therefore, the rear end side of the paper P can be stacked on the first movable plate 31.

  13A, when the paper P is stacked on the paper feed tray 11, the first and second slide plates 48 and 49 are both moved to the front side of the paper feed tray 11, and the locking lever. A first mode in which the second movable plate 41 is locked at substantially the same height as the upper surface 11 a of the paper feed table 11 via 45 can be adopted.

  When this first mode is obtained, the leading end of the stacked paper P in the paper feeding direction is held in parallel with the upper surface 11a of the paper feed table 11, so that the paper P can be reliably fed.

  Next, as shown in FIG. 13B, when the envelope F is stacked on the paper feed tray 11, the bottom Ft side, which is the top of the envelope F in the paper feeding direction, is thicker than the flap Ff side. Therefore, it is necessary to lower the bottom Ft side of the loaded envelope F, and when the envelope F is thin and the envelope F is light in weight, the repulsive force to the paper feeding roller 14 corresponds to the light weight of the envelope F. Must be set to be optimal.

  Therefore, when the user moves the switching operation knob 51 from the state of FIG. 13A to the rear side (arrow X2 direction side) by the first movement amount α1, the second slide plate 49 to which the switching operation knob 51 is fixed is also provided. It moves by the first movement amount α1.

  When the second slide plate 49 is moved rearward (arrow X2 direction side) by the first movement amount α1, the spring latching portion 41d1 formed on the right side 41d side of the second movable plate 41 and the second slide plate 49 is separated from the spring latching portion 49a formed in the first predetermined amount.

Accordingly, the tension spring 44 extends by a first predetermined amount toward the rear side (arrow X2 direction side) . Further, by being pushed by the urging force that by the torsion spring 4 7, the first slide plate 48 is moved rearward (the arrow X2 direction side).

  Thereafter, the first slide plate 48 abuts on the first slide plate pressing portion 49c formed at the rear end portion of the second slide plate 49, moves by the first movement amount α1, and stops.

  Further, when the first slide plate 48 is moved rearward (arrow X2 direction side), the lock on the lock lever 45 by the lock pin 50 fixed to the distal end portion of the first slide plate 48 is released.

  As a result, the locking lever 45 is rotated counterclockwise about the shaft 46 by the biasing force of the torsion spring 47, and the upper end portion 45 e (FIG. 10) of the locking lever 45 is the lower surface 41 b of the second movable plate 41. In order to move away from the second movable plate 41, the latching lever 45 is unlocked.

Then, the second movable plate 41, which has been unlocked, rotates clockwise around the shaft 43 against the urging force of the tension spring 44 in the counterclockwise direction due to the sheet loading weight . 2 The upper surface 41 a of the movable plate 41 is inclined obliquely downward with respect to the upper surface 11 a of the paper feed table 11. At this time, the shaft 43 of the second movable plate 41 reaches the right end in the escape hole 48 a provided near the tip of the first slide plate 48.

  Therefore, the bottom Ft, which is the leading edge of the envelope F in the sheet feeding direction, is supported so as to be lowered downward by the obliquely downward rotation of the second movable plate 41, but in the uppermost layer in which the bottoms Ft are stacked, 11 is substantially parallel to the upper surface 11a. Further, when the weight of the envelope F is light, the tension spring 44 extends by a first predetermined amount, whereby the first urging force by the tension spring 44 is transmitted to the second movable plate 41 and the paper feed roller 14 ( Since it acts as a repulsive force to FIG.

  Of course, when the envelope F is loaded, the first movable plate 31 that is pivotably provided at the rear portion of the paper feed table 11 has a predetermined inclination angle as described above with reference to FIG. Since it is inclined, the position between the flap portion Ff and the bottom portion Ft of the uppermost envelope F can take a posture (horizontal posture) substantially parallel to the upper surface 11a of the paper feed tray 11, so that the envelope F is not fed. And paper feeding errors such as double feeding do not occur.

  From the above, in FIG. 13B, when the light-weight envelope F is stacked on the paper feed tray 11, the second slide plate 49 is moved backward by the first movement amount α1 with respect to the first mode. Along with the movement operation, the first spring plate 48 is moved backward by the first movement amount α1 by the tension spring 44 to release the engagement of the second movable plate 41, and the spring of the second movable plate 41 is moved. By separating the latching portion 41d1 and the spring latching portion 49a of the second slide plate 49 by a first predetermined amount, a second mode in which a first biasing force is applied to the tension spring 44 can be taken.

  When this second mode is obtained, the repulsive force to the paper feed roller 14 can be set to be optimum corresponding to the light weight of the envelope F by the first urging force by the tension spring 44.

  Next, as shown in FIG. 13C, when the envelope F is stacked on the paper feed table 11, the bottom Ft on the paper feed direction side of the envelope F is made lower than the upper surface 11a of the paper feed table 11, When the paper quality of the envelope F is thick and heavy, it is necessary to set the repulsive force to the paper feeding roller 14 so as to be optimum corresponding to the heavy weight of the envelope F.

  Therefore, when the user moves the switching operation knob 51 from the state shown in FIG. 13A to the rear side (arrow X2 direction side) by the second movement amount α2 larger than the first movement amount α1, the switching operation knob 51 is moved. The second slide plate 49 to which is fixed also moves by the second movement amount α2.

  When the second slide plate 49 moves rearward (arrow X2 direction side) by the second movement amount α2, the spring latching portion 41d1 formed on the right side 41d side of the second movable plate 41 and the second slide plate 49 is separated by a second predetermined amount larger than the first predetermined amount.

  As a result, the tension spring 44 extends toward the rear side (arrow X2 direction side) by a second predetermined amount, so that it is pulled by the second biasing force by the tension spring 44 and the first slide plate 48 is rearward ( When moving in the direction of the arrow X2), the shaft 43 of the second movable plate 41 reaches the right end in the escape hole 48a provided near the tip of the first slide plate 48. Since the movement is restricted, the first slide plate 48 moves by the first movement amount α1 and stops.

  Along with the movement of the first slide plate 48, the locking to the second movable plate 41 by the locking lever 45 is released by the same operation as in the case of FIG. Rotates clockwise about the shaft 43.

  Then, the upper surface 41 a of the second movable plate 41 that has been unlocked is inclined obliquely downward from the upper surface 11 a of the paper feed table 11.

  Accordingly, the bottom Ft, which is the top of the envelope F in the sheet feeding direction, is supported so as to be lowered downward by the second movable plate 41 turning obliquely downward, as in FIG. The stacked uppermost layer takes a posture substantially parallel to the upper surface 11 a of the paper feed table 11. Further, when the envelope F is heavy, the tension spring 44 extends by a second predetermined amount larger than the first predetermined amount, so that the second urging force of the tension spring 44 is applied to the second movable plate 41. Since it is transmitted and acts as a repulsive force to the paper feed roller 14 (FIG. 3), an optimum paper feed pressure can be obtained for the heavy weight of the envelope F.

  From the above, in FIG. 13C, when the heavy envelope F is stacked on the paper feed tray 11, the second movement plate 49 is moved rearward with respect to the first mode. Along with the movement of the second movement amount α2 that is larger than the first movement plate 41, the first slide plate 48 is moved backward by the first movement amount α1 by the tension spring 44 to release the locking of the second movable plate 41. At the same time, the spring hooking portion 41d1 of the second movable plate 41 and the spring hooking portion 49a of the second slide plate 49 are separated by a second predetermined amount larger than the first predetermined amount. A third mode in which a second biasing force larger than the first biasing force is applied to the spring 44 may be employed.

  When this third aspect is obtained, the repulsive force to the paper feed roller 14 can be set to be optimum corresponding to the heavy weight of the envelope F by the second urging force of the tension spring 44.

  In this embodiment, the biasing force of the tension spring 44 biasing the first slide plate 48 is divided into two stages corresponding to the weight of the envelope F by the operations of the first and second slide plates 48 and 49. Although the sheet feeding performance to the envelope F is improved by switching, when the sheet feeding device 10 (FIG. 3) is configured at a low cost, a structure form in which the urging force of the tension spring 44 is not switched is possible. However, the second movable plate 41 may be structured so as to be able to take a locked state and an inclined state.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus (image forming apparatus), 2 ... One side plate,
10: Paper feeding device,
DESCRIPTION OF SYMBOLS 11 ... Paper feed stand, 11a ... Upper surface, 11b, 11c ... Rectangular hole, 11d ... 1st movable board accommodating part,
11e, 11f... Right and left side surfaces, 11g.
12L, 12R ... a pair of left and right guide fences, 13 ... a guide shaft,
14 ... feed roller, 15 ... wheat roller, 17 ... friction plate,
20: Lifting means,
30: Envelope flap support means,
31 ... 1st movable plate (envelope flap part support movable plate),
31a ... front surface, 31b ... rear surface, 31b1 ... engaged recess,
32 ... 1st shaft, 33 ... Torsion spring, 34 ... 2nd shaft,
35 ... cam plate, 35a ... convex portion, 35b ... concave portion, 36 ... switching operation lever,
40 ... Envelope bottom support means,
41 ... 2nd movable plate (envelope bottom part support movable plate), 41a ... upper surface, 41b ... lower surface,
41c, 41d ... left and right side surfaces, 41c1, 41d1 ... spring hooking portions,
42 ... a friction member, 43 ... a pair of left and right shafts, 44 ... a pair of left and right tension springs,
45 ... locking lever, 45a ... front face, 45b ... rear face, 45c, 45d ... left and right side faces,
45d1 ... Spring hooking part, 45d2 ... Locked recess, 45e ... Upper end part,
46 ... shaft, 47 ... torsion spring, 48 ... first slide plate,
49 ... 2nd slide plate, 49a ... Spring latching part, 49c ... 1st slide plate press part,
50 ... locking pin, 51 ... switching operation knob,
F ... Envelope, Fa ... Cover, Fb ... Back paper, Ff ... Flap part, Fn ... Paste, Fe ... Bottom part,
P: Paper.

Claims (5)

Multiple sheets of either paper or envelopes can be stacked on the upper surface of the paper feed tray, and in the case of the envelope, the bottom side of the envelope that is thicker than the thin flap side is the feed direction. In the sheet feeding device that is set and loaded on the downstream side of the sheet, and feeds the stacked uppermost sheet or envelope by a sheet feeding roller,
It is movably provided on the upstream side of the paper feed direction of the paper feed tray. When stacking the paper, the front surface is stored at substantially the same height as the upper surface of the paper feed tray, while the envelope is loaded. In this case, a first movable plate that is inclined upward from the upper surface of the paper feed table so as to lift and support the flap side of the envelope.
The sheet feeding table is rotatably provided on the downstream side in the sheet feeding direction. When stacking the sheets, the upper surface is locked at substantially the same height as the upper surface of the sheet feeding table. A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
A cam plate fixed to a shaft rotatable in a first movable plate housing portion formed on the upstream side in the paper feed direction of the paper feed table and contacting and separating from a rear surface of the first movable plate;
A switching operation lever fixed to the shaft extending from one side of the sheet feed base to the side of the first movable plate storage unit,
A sheet feeding device characterized in that an inclination angle of the first movable plate is varied according to a rotation angle of the cam plate when the switching operation lever is operated. Multiple sheets of either paper or envelopes can be stacked on the upper surface of the paper feed tray, and in the case of the envelope, the bottom side of the envelope that is thicker than the thin flap side is the feed direction. In the sheet feeding device that is set and loaded on the downstream side of the sheet, and feeds the stacked uppermost sheet or envelope by a sheet feeding roller,
It is movably provided on the upstream side of the paper feed direction of the paper feed tray. When stacking the paper, the front surface is stored at substantially the same height as the upper surface of the paper feed tray, while the envelope is loaded. In this case, a first movable plate that is inclined upward from the upper surface of the paper feed table so as to lift and support the flap side of the envelope.
The sheet feeding table is rotatably provided on the downstream side in the sheet feeding direction. When stacking the sheets, the upper surface is locked at substantially the same height as the upper surface of the sheet feeding table. A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
A locking lever provided rotatably on the lower surface side of the second movable plate while being biased by a torsion spring in the inclination direction of the second movable plate;
A first slide slides between a downstream side in the paper feeding direction and an upstream side opposite to the downstream side along one side surface of the paper feed table, and a locking pin is fixed to the downstream side. A slide plate,
A spring latching portion formed on the downstream side so as to be opposed to a spring latching portion formed on the second movable plate, a first slide plate pressing portion formed on the upstream side, and the downstream side And a switching operation knob fixed between the upstream side and the upstream side, and slides between the downstream side in the paper feeding direction and the upstream side opposite to the downstream side along the first slide plate. A second slide plate that
A tension spring latched between a spring latching portion of the second movable plate and a spring latching portion of the second slide plate,
When the switching operation knob is operated to move both the first and second slide plates to the downstream side when the paper is loaded, the second lever is engaged by locking the locking lever via the locking pin. The plate is locked, and on the other hand, when the envelope is loaded, the switching operation knob is operated to move the first and second slide plates to the upstream side by a first predetermined amount from the time of locking to the locking lever. The first lever is applied to the tension spring by releasing the locking to the second movable plate by the locking lever, and the second slide plate is operated by operating the switching operation knob. Only when the first slide plate is moved to the upstream side by a second movement amount larger than the first movement amount, the first slide plate moved by the first predetermined amount is locked to the second movable plate. The second larger than the first urging force is applied to the tension spring while releasing Sheet feeding apparatus characterized by imparting force. Multiple sheets of either paper or envelopes can be stacked on the upper surface of the paper feed tray, and in the case of the envelope, the bottom side of the envelope that is thicker than the thin flap side is the feed direction. In the sheet feeding device that is set and loaded on the downstream side of the sheet, and feeds the stacked uppermost sheet or envelope by a sheet feeding roller,
The envelope is movably provided on the upstream side in the sheet feeding direction of the sheet feeding table. When stacking the sheets, the front surface takes a first posture substantially the same as the upper surface of the sheet feeding table, while the envelope A first movable plate that takes a second posture inclined upward from the upper surface of the paper feed base so as to lift and support the flap portion side of the envelope upward,
The secured to feed table of the sheet feeding direction of the first movable plate receiving portion in rotatable shaft formed on the upstream side, and the cam plate toward or away on a rear surface of the first movable plate, and the second A switching operation lever fixed to the shaft extending from one movable plate housing portion to one side surface of the paper feed base, and according to the rotation of the cam plate when the switching operation lever is operated First movable plate moving means for moving the first movable plate so as to be able to take the first posture and the second posture;
The sheet feeding table is rotatably provided on the downstream side in the sheet feeding direction. When stacking the sheets, the upper surface is locked at substantially the same height as the upper surface of the sheet feeding table. A second movable plate that inclines downward from the top surface of the paper feed base so as to support the envelope by lowering the bottom side of the envelope downward.
Has a lower surface opposite to the engaging lever rotatably provided in the second movable plate in the feeding table of the paper feed direction of the lower flow side, in response to said rotation of said locking lever first A second movable plate locking and unlocking means for locking the movable plate at the time of loading the paper while releasing the lock to the second movable plate at the time of loading the envelope;
A paper feeding device comprising: The second movable plate locking and unlocking means are:
The locking lever provided rotatably on the lower surface side of the second movable plate while being urged in the tilt direction of the second movable plate by a torsion spring;
A first slide plate that slides between a downstream side in the paper feeding direction and an upstream side opposite to the downstream side along one side surface of the paper feed table;
The first slide plate is fixed to the downstream side of the first slide plate, and when the first slide plate moves to the downstream side, the first movable plate is engaged with the locking lever to lock the second movable plate. A locking pin that releases the locking of the locking lever as the slide plate moves to the upstream side;
A spring latching portion formed on the downstream side so as to be opposed to a spring latching portion formed on the second movable plate, a first slide plate pressing portion formed on the upstream side, and the downstream side And a switching operation knob fixed between the upstream side and the upstream side, and slides between the downstream side in the paper feeding direction and the upstream side opposite to the downstream side along the first slide plate. A second slide plate that
A tension spring latched between a spring latching portion of the second movable plate and a spring latching portion of the second slide plate ,
When the switching operation knob is operated and the second slide plate is moved to the downstream side when the paper is loaded, the first slide plate is moved to the downstream side by the first slide plate pressing portion and the locking is performed. The locking lever is locked via a pin to lock the second movable plate. On the other hand, when the envelope is loaded, the switching operation knob is operated to move the second slide plate to the upstream side. Along with this, the first slide plate is moved to the upstream side to release the locking to the second movable plate by the locking lever, and the second movable plate is moved below the upper surface of the paper feed table. The sheet feeding device according to claim 3, wherein the sheet feeding device is tiltable toward the front . A first mode in which the first and second slide plates are both moved to the downstream side, and the second movable plate is locked at substantially the same height as the upper surface of the sheet feed table via the locking lever. When,
Along with the operation of moving the second slide plate to the upstream side by the first movement amount relative to the first mode, the first slide plate is moved to the upstream side by the first movement amount. The second movable plate is unlocked and the spring latching portion of the second movable plate and the spring latching portion of the second slide plate are separated by a first predetermined amount, A second mode for applying a first biasing force to the tension spring;
With the operation of moving the second slide plate to the upstream side by a second movement amount larger than the first movement amount with respect to the first mode, the first slide plate is moved to the upstream side. The second movable plate is released by being moved by the first movement amount, and the second movable plate and the second slide plate are latched between the spring latching portion and the spring latching portion of the second slide plate. A third mode in which a second biasing force larger than the first biasing force is applied to the tension spring by being separated by a second predetermined amount larger than a predetermined amount of 1,
Sheet feeding apparatus according to claim 4, characterized in Toridoku Rukoto a.

Images