JPH0329702B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to press-contact a recording sheet in a sheet feeding cassette to a sheet feeding means in order to supply the recording sheet into an image recording device such as a copying machine. The present invention relates to a sheet pressurizing device, and more particularly, to an improvement in a pressurizing/release guide mechanism for smoothly performing pressurizing and releasing operations of the sheet pressurizing device as a cassette is attached and removed.

[Prior art]

In general, copying machines include figures 1 and 2 a and b.
As shown in the figure, a cassette receiving section 2 into which the paper feeding cassette 1 is inserted is formed, and within this cassette receiving section 2 there is provided a paper feeding means disposed above the cassette 1 when the cassette 1 is mounted. A paper pressure device A is provided for pressing the paper 4 in the cassette 1 onto the paper feed roll 3 as shown in FIG.

Conventionally, as shown in FIGS. 1 and 2a and 2b, this type of paper pressure device has been provided with a rotation shaft 5 extending in the width direction on the back side of the cassette receiving section 2, and this rotation A pressure lever 6 having a substantially L-shaped cross section is fixed to approximately the center of the shaft 5, and this pressure lever 6
There is one in which the rotatable free end of the cassette 1 is opposed to the insertion direction m of the cassette 1, and the pressure lever 6 is always urged upward by a pressure spring (not shown). In this type, the pressure lever 6 is
As shown in FIGS. 1 and 2b, a bottom plate 8 is inserted into the cassette 1 from the bottom wall hole 7 of the cassette 1 when the cassette 1 is installed, and has one end pivotally supported on the bottom wall of the cassette 1. The paper 4 is pressurized through the paper feed roll 3, and the paper 4 is brought into pressure contact with the paper feed roll 3.

However, in such a paper pressure device, the pressure lever 6 is always urged upward by a pressure spring, so before the cassette 1 is installed, the pressure lever 6 is , Figure 2a
As shown by the solid line in , it is held in a free position facing obliquely upward with respect to the insertion direction m of the cassette 1, and is arranged so as to block the mounting space for the cassette 1. In this case, if the pressure lever 6 is in the free position when the cassette 1 is installed, the insertion side end wall of the cassette 1 will interfere with the pressure lever 6. In the process of inserting the cassette 1, as shown by solid lines and imaginary lines in FIG.
When the cassette 1 is completely installed, as shown in FIG.
must be pressurized. On the other hand, when the cassette 1 is removed, the pressure applied to the sheets 4 by the pressure lever 6 must be released.

In order to enable such a pressurizing operation and a pressurizing release operation of the paper pressurizing device, the conventional paper pressurizing device A performs pressurizing and releasing operations as shown in FIGS. 1 and 3 a and b. It is equipped with a guide mechanism G. this is,
A pair of guide arms 10 are fixed to both ends of the rotating shaft 5 of the pressure lever 6, and the rotatable free ends of the guide arms 10 are inserted into the cassette receiving portion 2 from the pressure lever 6.
A guide roller 11 is rotatably supported at each of the rotatable free ends of the guide arm 10, and isometric stands are provided on both sides of the cassette 1, the upper side of which is longer than the lower side when viewed from the side. The shaped guide locus forming body 12 is formed to bulge, and when the cassette 1 is attached or removed, both side surfaces and the bottom surface of the guide locus forming body 12 in the longitudinal direction of the cassette 1 are formed into guide tapered surfaces 12a, 1.
2b and the guide lower surface 12c, by sliding the guide roller 11, the guide arm 1
0 (for example, Japanese Patent Application Laid-Open Nos. 57-72529, 166236-1980, 119638-1980, 1986-119638,
No. 55-16821, Utility Model No. 142509, Utility Model No. 54-142509, Utility Model No. 56-
(See Publication No. 20934). Note that the reference numeral 13 is a pressure spring.

According to such a pressurization/release guide mechanism, for example, when the cassette 1 is installed, the cassette receiving part 2
As you insert cassette 1 into the guide roller 1
1 comes into contact with the upper edge of the guide tapered surface 12a, as shown by the solid line in FIG. 3a, and then slides downward along the guide tapered surface 12a.
As shown by the imaginary line in , it crosses over the guide tapered surface 12a and reaches the guide lower surface 12c. In this case, if the guide arm 10 is configured to rotate downward by a predetermined angle α from the position shown by the solid line in FIG. 3a to the position shown by the imaginary line, the pressure lever 6 The cassette 1 is pushed down to the lower part of the cassette 1, as shown by the imaginary line in FIG.

Thereafter, the guide roller 11 slides along the lower guide surface 12c for a while, but during this time the guide arm 10 maintains the position shown by the imaginary line in FIG. is also held below the cassette 1, thereby avoiding interference between the pressure lever 6 and the cassette 1. When the guide roller 11 gets over the lower guide surface 12c, the pressure spring 1
Since the guide arm 10 is lifted by the biasing force of 3, the pressure lever 6 that has reached the bottom wall hole 7 of the cassette 1 is lifted upward, as shown in FIG. Pressure is applied to the paper 4. At this time, the guide roller 11
As shown in Figure b, it slides upward along the guide tapered surface 12b and stops at a predetermined position. When the cassette 1 is detached, the guide roller 11 slides downward along the guide tapered surface 12b and rides on the lower guide surface 12c, so that the pressure lever 6 moves downward from the cassette 1 via the guide arm 10. The pressure lever 6 releases the pressure on the paper 4, and then the guide roller 11 slides from the guide lower surface 12c along the guide tapered surface 12a, and the guide It is separated from the trajectory forming body 12.
At this stage, the pressure lever 6 is moved as shown in FIG.
It returns to the free position shown by the solid line.

[Problem to be solved by the invention]

By the way, in the case of such a conventional pressurization/release guide mechanism, as shown in FIG. sometimes,
The guide arm 10 must be rotated with the maximum rotation angle α. At this time, in order to maintain good workability for mounting the cassette 1, the guide roller 11 provided on the guide arm 10 is moved to the guide tapered surface 12a of the guide locus forming body 12 within the range of the maximum vertical movement l of the guide arm 10. , the height h of the guide locus forming body 12 is set corresponding to the maximum vertical movement distance l. However, in the conventional pressure/release guide mechanism, in order to prevent interference between the pressure lever 6 and the cassette 1, the length of the guide arm 10 is longer than the rotation axis 5 of the pressure lever 6.
Since the maximum vertical movement distance l of the guide arm 10 is set to be longer than the length between the rotation free end and the rotation free end, the maximum vertical movement distance l of the guide arm 10 is necessarily longer than that of the rotation free end l' (second (see Figure a). In this case, since the maximum vertical movement l' of the free rotation end of the pressure lever 6 corresponds approximately to the paper storage capacity in the cassette 1, the guide arm 1
0, the maximum vertical movement distance l, in other words, the height h of the guide locus forming body 12 greatly exceeds the paper storage capacity, and the height of the cassette 1 itself increases accordingly. The cassette 1 itself has to be set larger than the storage capacity, and not only does the cassette 1 itself become unnecessarily large, but the space inside the cassette holder 2 also has to be made larger than necessary. ing. Such problems become more pronounced as the length of the guide arm 10 is increased in order to reduce the operating force required when attaching and detaching the cassette 1.

This invention was made with attention to the above technical problems, and it is possible to miniaturize the cassette and minimize the space of the cassette holder without complicating the mechanism itself. The present invention provides a pressure/release guide mechanism in a sheet pressure device of a recording device.

[Means to solve the problem]

That is, in the present invention, a pressure lever is rotatably provided in a cassette receiving portion of an image recording apparatus into which a sheet feeding cassette is inserted and mounted, and the rotatable free end of this pressure lever is arranged to face the insertion direction of the cassette. At the same time, the pressure lever is always urged upward via the biasing means, and when the cassette is installed, the pressure lever is guided into the bottom wall hole of the cassette by the pressure/release guide mechanism, and the pressure lever is guided into the bottom wall hole of the cassette. The recording sheet is pressurized and the recording sheet is brought into pressure contact with a sheet feeding means disposed above the cassette, and when the cassette is removed, the pressure applied to the recording sheet by the pressure lever is removed. A guide arm is provided on the side of the cassette receiver coaxially with the pressure lever and protrudes toward the entrance side of the cassette receiver from the rotatable free end of the pressure lever, assuming the sheet pressure device of a recording device. The guide arm is arranged so as to protrude from the rotatable free end toward the entrance side of the cassette receiving part, and the position facing diagonally downward with respect to the cassette insertion direction is the swinging bottom dead center, and the position along the cassette insertion direction is the swinging bottom dead center. As a swing point, a guide cam is rotatably supported on the free rotation end of the guide arm, and a guide cam is provided on the side surface of the cassette with a predetermined guide trajectory, and when the cassette is attached or removed, the guide cam follows the guide trajectory. and a guide track forming member that slides along the guide arm and temporarily moves the pressure lever to the lower part of the cassette via the guide arm.

[Effect]

According to the above-mentioned technical means, when the cassette is installed, the guide cam, which is pivotally supported by the free rotation end of the guide arm, slides along the guide trajectory forming body on the cassette side, and the guide arm reaches its maximum rotation. The guide arm rotates downward with an angle of movement, and the free rotation end of the guide arm moves with the maximum vertical movement distance.

At this time, if the guide arm is at the uppermost position, the guide cam is in a position diagonally downward with respect to the insertion direction of the cassette (swinging bottom dead center).
On the other hand, when the guide arm is at the lowest position, the guide cam maintains a posture along the cassette insertion direction, so the vertical movement distance of the tip of the guide cam is equal to the maximum vertical movement of the guide arm. It will be less than the transportation cost.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. Components that are the same as those in the prior art are designated by the same reference numerals as in the prior art, and detailed explanation thereof will be omitted here.

In the first embodiment shown in FIGS. 4 to 7, the pressure/release guide mechanism G in the paper pressure device is a guide fixed to both ends of the rotating shaft 5 of the pressure lever 6, as in the conventional case. The cassette 1 is provided with an arm 10 and a guide trajectory forming body 12 formed on both sides of the cassette 1, but unlike the conventional case, a guide tapered surface of the guide trajectory forming body 12 is provided at the free rotation end of the guide arm 10. 12a, 12b and guide lower surface 12c
A guide cam 20 is provided that slides along.

In this embodiment, the guide cam 20 is
In particular, as shown in FIGS. 5 and 6, the guide cam 20 has an oval cross-section, and its base end is attached to the shaft 2 at the free rotation end of the guide arm 10.
By being pivotally supported by the guide arm 1
The guide cam 20 is mounted so as to be swingable in the vertical direction with respect to the guide arm 10, and the tip of the guide cam 20 is arranged to protrude from the rotationally free end of the guide arm 10 toward the entrance side of the cassette receiving section. And the guide cam 20
The movement range is the extension line 10a of the guide arm 10.
, a posture facing diagonally downward by a predetermined angle is defined as the swing bottom dead center P ₁ , and a posture facing diagonally upward by a predetermined angle is defined as the swing top dead center P ₂ . P ₁ means that no matter what rotational position the guide arm 10 is in, the guide cam 2
0 is set so that it can take a posture diagonally downward with respect to the insertion direction m of the cassette 1, while the swinging top dead center _P2 is set such that when the guide arm 10 reaches the lowest position, The guide cam 20 is set so that it can assume a posture along the insertion direction m of the cassette 1. Furthermore, the guide cam 2
The means for regulating the swing range of 0 is, for example, a stopper flange 22 bent and formed on the upper edge of the guide arm 10, and a stopper protrusion protruding from the proximal arcuate surface 20a of the guide cam 20. 23, the swinging bottom dead center P ₁ of the guide cam 20 is regulated by bringing the stopper protrusion 23 into contact with the stopper flange 22, while the swinging top dead center P ₂ of the guide cam 20 is regulated by bringing the upper surface of the guide cam 20 into contact with the longitudinal edge of the stopper flange 22.

Next, the operation of the pressure/release guide mechanism according to this embodiment will be described.

First, in the case of guiding the pressurizing operation of the paper pressurizing device when the cassette 1 is installed, when the cassette 1 is inserted into the cassette receiving part 2 (see Fig. 1), the guide cam 2
0 is the bottom dead center of the swing, as shown by the solid line in Figure 4a.
After contacting the upper edge of the guide tapered surface 12a of the guide trajectory forming body 12 with a stable posture of _P1 , it slides downward along the guide tapered surface 12a while maintaining the posture of the swinging bottom dead center _P1 . As shown by the imaginary line in FIG. 4a, it moves over the guide tapered surface 12a to reach the guide lower surface 12c, and maintains the posture along the insertion direction m of the cassette 1. In this case, as the guide cam 20 moves, the guide arm 1
0 will be rotated downward by a predetermined angle from the position shown by the solid line in FIG. 4a to the position shown by the imaginary line.
The rotation angle of the guide arm 10 is controlled by the pressure lever 6.
If the pressure lever 6 is set at an angle α necessary for moving from the free position to the lower part of the cassette 1, the pressure lever 6 will move as shown by the imaginary line in FIG. 2a.
It is pushed down to the lower part of the cassette 1. Thereafter, the guide cam 20 moves toward the lower guide surface 12 while maintaining the posture along the insertion direction m of the cassette 1.
It slides along c. At this time, the guide arm 10 maintains the position shown by the imaginary line in FIG. Ru. When the guide cam 20 gets over the lower guide surface 12c, the guide arm 10 is lifted by the biasing force of the pressure spring 13, as shown in FIG. 4b.
As shown in FIG. 2b, the bottom wall hole 7 of the cassette 1
When the pressure lever 6 reaches this point, it is lifted upward and presses the paper 4 in the cassette 1 via the bottom plate 8. At this time, as shown in FIG. 4b, the guide cam 20 slides upward along the guide tapered surface 12b while maintaining the attitude of the swinging top dead center _P2 , and stops at a predetermined position. ing. This completes the pressurizing operation of the paper 4.

Conversely, if we consider the case of guiding the pressure release operation of the paper pressure device when the cassette 1 is removed,
As shown by the arrow n in Fig. 4b, the cassette receiver 2
When the cassette 1 is removed from the guide tapered surface 12b, the guide cam 20, which had stopped at a predetermined position on the guide tapered surface 12b, slides downward along the guide tapered surface _12b while maintaining the swinging top dead center P2. As the cassette 1 moves, it rides on the lower guide surface 12c and maintains the posture along the insertion direction m of the cassette 1. At this time, the pressure lever 6 moves the cassette 2 through the guide arm 10.
Since the paper 4 is pushed down to the lower part, the state in which the paper 4 is pressed by the pressure lever 6 is released. After this, when the cassette 1 is further removed, the guide cam 20 moves toward the lower guide surface 12c while maintaining the posture along the insertion direction m of the cassette 1.
, and climbs over the lower guide surface 12c. Then, the guide arm 10 is lifted by the biasing force of the pressure spring 13, so the guide cam 20 slides upward along the guide tapered surface 12a while maintaining the posture of the swing bottom dead center _P1 . Finally, the guide trajectory forming body 12
distance from. At this stage, the pressure lever 6 returns to the free position shown in solid line in FIG. 2a. With this, the operation of releasing the pressure on the paper 4 is completed.

In such a guiding process, the guide arm 10 rotates downward at the maximum rotation angle α when the cassette 1 is attached, and at this time, as shown in FIG. 10
Suppose that the rotation free end of is moved with the maximum vertical movement distance l. In this case, the guide arm 10
When the guide arm 10 is at the uppermost position, the guide cam 20 maintains the posture of the swinging bottom dead center _P1 , and when the guide arm 10 is at the lowermost position, the guide cam 20 moves along the insertion direction m of the cassette 1. Since the posture is maintained, the tip arcuate surface 20b of the guide cam 20 moves along the guide tapered surface 12a with a maximum vertical movement _l0 smaller than the maximum vertical movement l of the guide arm 10. become. Therefore, the height h ₀ of the guide locus forming body 12 necessary to maintain good workability in mounting the cassette 1 can be set in accordance with the maximum vertical movement distance l ₀ of the guide cam 20 . At this time, the maximum vertical movement _l0 of the guide cam 20 is smaller than that of the guide arm 10, so that the cassette 1
Therefore, the fact that the height dimension h ₀ of the guide trajectory forming body 12 unnecessarily exceeds the paper storage capacity compared to the conventional case can be eliminated. . Therefore, there is no need to unnecessarily increase the height of the cassette 1 itself beyond the paper storage capacity;
Not only can the cassette 1 itself be made smaller, but also the space within the cassette receiving section 2 can be reduced.

In addition, in this embodiment, the guide cam 2
0 is the guide lower surface 12c of the guide trajectory forming body 12
Since the position along the insertion direction m of the cassette 1 is maintained when the cassette 1 is slid, the situation where the guide cam 20 becomes an external protrusion that unnecessarily protrudes from the bottom wall of the cassette 1 when the cassette 1 is attached or removed is avoided. Due to the presence of the guide cam 20, there is no concern that the space within the cassette receiving section 2 will become unnecessarily wide.

Next, a second embodiment shown in FIGS. 8 to 10 will be described.

The guide cam 30 according to this embodiment has an oval cross-section like the first embodiment, but
Unlike the first embodiment, the guide cam 2 of the first embodiment
It has a long axis dimension longer than 0, and its central portion is pivotally supported on the rotatable free end of the guide arm 10. A hook-shaped stopper piece 31 is protruded from the upper edge of the guide arm 10 near the free rotation end.
The swing range of the guide cam 30 is restricted by bringing the upper surfaces of the guide cam 30 closer to both ends in the longitudinal direction into contact with each other. In this embodiment, the swing bottom dead center P ₁ of the guide cam 30 is as in the first embodiment,
Although the guide cam 30 is set to face diagonally downward with respect to the insertion direction m of the cassette 1,
The swinging top dead center P ₂ ' of the cassette ₁ is located higher than that of the first embodiment, and is set in a position diagonally upward with respect to the insertion direction m of the cassette 1.

Therefore, according to this embodiment, in addition to providing the same functions and effects as those of the first embodiment, it is possible to set the height of the cassette 1 smaller than that of the first embodiment. That is, in the first embodiment, when pressurizing the paper, the guide taper of the guide locus forming body 12 is formed at a position where the base end side circular arc surface 20a of the guide cam 20 is approximately equal to the rotation free end position of the guide arm 10. It will slide on the surface 12b. Therefore, in order to ensure the engagement state between the guide cam 20 and the guide locus forming body 12 and maintaining good ease of detachment of the cassette 1, the height dimension h ₀ of the guide locus forming body 12 must be The rotational free end of the guide arm 10 must be set to a stroke S ₀ (see FIG. 10) or more that allows the rotation free end of the guide arm 10 to move in the vertical direction during pressure. On the other hand, in this embodiment, since the guide cam 30 maintains the attitude of the swinging top dead center P ₂ ' when pressurizing the paper,
The one-end circular arc surface 30a of the guide cam 30 slides on the guide tapered surface 12b of the guide trajectory forming body 12 below the rotation free end position of the guide arm 10. At this time, the guide cam 3
Since the stroke S ₁ by which the one end side circular arc surface 30a of 0 can move in the vertical direction when pressurizing the paper is smaller than the stroke S ₀ of the guide arm 10, the height of the guide trajectory forming body 12 is adjusted accordingly. The dimension h ₁ can be set smaller than the dimension h ₀ of the first embodiment. Therefore, the height of the cassette 1 itself can be set smaller than in the first embodiment.

In addition, in each of the above embodiments, the guide cam 2
0 and 30 are both constructed as a single piece with an oval cross-section, but they are not necessarily limited to this. For example, as shown in FIGS. 11 and 12, a plate-shaped base plate 41, for example, is A guide cam 40 that supports a pair of rollers 42 and 43
There is no problem in using it as In this case, since the rollers 42 and 43 slide along the guide locus forming body 12, the sliding resistance between the guide arm 40 and the guide locus forming body 12 is smaller than in each of the above embodiments. , the operating force for attaching and detaching the cassette 1 is reduced. Further, the guide arm 10 and the guide locus forming body 12 are not limited to those shown in the above embodiments, and may be modified in design as appropriate.

〔Effect of the invention〕

As explained above, according to the pressure/release guide mechanism in the sheet pressure device of the image recording apparatus according to the present invention, the guide cam is attached to the free rotation end of the guide arm, and the guide trajectory forming body on the cassette side is attached to the guide cam. Since the guide cam is engaged and the vertical movement of the tip of the guide cam is made smaller than the maximum vertical movement of the guide arm, the height of the guide trajectory forming body on the cassette side can be made smaller than before. As a result, the cassette itself can be made smaller and the space within the cassette receiving section can be kept to the minimum necessary. Further, according to the present invention, a guide cam is used in place of the guide roller used in the conventional pressure/release guide mechanism, so there is no concern that the mechanism itself will become unnecessarily complicated.

[Brief explanation of the drawing]

FIG. 1 is an explanatory plan view showing an example of a paper pressure device of a conventional copying machine, and FIGS. 2a and 2b are cross-sectional views taken along the line in FIG. FIGS. 3a and 3b are cross-sectional views taken along the line of FIG.
Figures 4a and 4b show a first embodiment of the pressure/release guide mechanism according to the present invention, and are sectional views showing the guiding process corresponding to Figures 2a and b, and Figure 5 shows the details of the guide cam. Fig. 4 is an explanatory view of the main parts of Fig. 4 a and b showing the main structure, Fig. 6 is a view seen from the direction of the arrow in Fig. 5, Fig. 7 is an enlarged explanatory view of Fig. 4 a, and Fig. 8 is an explanatory view of this A main part explanatory diagram corresponding to FIG. 5 showing a second embodiment of the pressure/release guide mechanism according to the invention, FIG. 9 is a view taken from the direction of the arrow in FIG. 8, and FIG. 10 is a paper pressurization diagram. Main part explanatory diagram showing the operation of the pressurization/release guide mechanism at the time, Part 1
1 is an explanatory view corresponding to FIG. 5 showing a modification of the guide cam, and FIG. 12 is a view taken from the direction of arrow XII in FIG. 11. Description of symbols, A... Paper pressure device (sheet pressure device), G... Pressure/release guide mechanism, m... Cassette insertion direction, P ₁ ... Rocking bottom dead center, P ₂ , P ₂ ′...
Swing top dead center, 1...cassette, 2...cassette receiver, 3...paper feed roll (sheet feeding means), 4...
... Paper (recording sheet), 5 ... Rotating shaft, 6 ... Pressure lever, 7 ... Hole, 8 ... Bottom plate,
10... Guide arm, 12... Guide locus forming body, 20, 30, 40... Guide cam.

Claims (1)

[Scope of Claims] 1. A pressure lever 6 is rotatably provided in the cassette receiving section 2 of the image recording apparatus into which the sheet feeding cassette 1 is inserted and mounted, and the rotatable free end of the pressure lever 6 is connected to the cassette. 1, and the pressure lever 6 is constantly urged upward via the urging means 13, and the pressure/release guide mechanism G causes the bottom wall of the cassette 1 to The pressure lever 6 is guided into the hole 7 to pressurize the recording sheet 4 in the cassette 1, and the recording sheet 4 is brought into pressure contact with the sheet feeding means 3 disposed above the cassette 1, while the cassette 1 is removed. Sometimes, in a sheet pressing device of an image recording apparatus which releases the pressurized state of the recording sheet 4 by the pressure lever 6, a sheet pressure device is provided on the side of the cassette receiving part 2 coaxially with the pressure lever 6, A guide arm 10 is arranged to protrude from the rotatable free end of the pressure lever 6 toward the inlet side of the cassette receiver 2; The guide arm 10 is pivotably supported on the rotatable free end of the guide arm 10, with the position facing diagonally downward with respect to the insertion direction of the cassette 1 as the bottom dead center of swing, and the position along the insertion direction of the cassette 1 as a swing point. Guide cam 20,3
The guide cams 20, 30, 40 are provided on the side surface of the cassette 1 with a predetermined guide trajectory, and when the cassette 1 is attached or removed, the guide cams 20, 30, 40 slide along the guide trajectory, and the guide arm 10 is moved. A pressurizing/release guide mechanism in a sheet pressurizing device of an image recording apparatus, comprising a guide locus forming member 12 for temporarily moving a pressurizing lever 6 to a lower part of a cassette 1 through the pressurizing lever 6.