JP2003295355A - Opening and closing apparatus for original press-contact plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an opening and closing apparatus for an original press- contact plate in which safety can be improved by making a damper function effective throughout the closing process of the original press-contact plate. <P>SOLUTION: A damper device 24 is provided between a support arm 7 and a slider 15 receiving the rear end part of a compression coil spring 16. The damper device 24 comprises a damper base 27 which is fixed to the support arm 7 and has grooves 25 and projection streaks 26, which are long in the front-rear direction, on the reverse surface alternately in the right-left direction, projection streaks 28 and grooves 29 which are formed on the top surface of the slider 15 to slidably engage the grooves 25 and projection streaks 26, and grease 30 interposed between the reverse surface of the damper base 27 and the top surface of the slider 15. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printing machine,
The present invention relates to an opening / closing device for an original pressing plate suitably used for a scanner or the like. 2. Description of the Related Art An opening / closing device of this kind for an original cover is disclosed, for example, in Utility Model Registration No. 2589714 (Japanese Utility Model Application Laid-open No.
4051) It is publicly known. As shown in FIG. 6 and FIG.
A mounting arm 41 attached to the rear end of the document, and a support arm 43 of a document pressure plate 49 pivotally connected at one end to both side plates of the mounting member 41 via hinge pins 42 so as to be rotatable.
And a compression coil spring 48 mounted between the support arm 43 and the mounting member 41 so as to urge the support arm 43 to rotate in the opening direction. And manuscript 5
The document pressing plate 49 is automatically closed from a predetermined closing angle in order to press the document
The weight of the original cover plate 49 is configured to be greater than the elasticity of the compression coil spring 48 from a predetermined closing angle of about 20 ° so that the contact plate 1 can be pressed on the contact glass 50.
At this time, the attachment member 41 and the support arm 4 are so positioned that the original cover 49 does not drop sharply and pinch a hand.
3, a fluid damper device 52 that operates only at a predetermined closing angle of about 10 ° or less of the support arm 43 is provided. The fluid damper device 52 includes an oil damper, and is housed inside the compression coil spring 48. However, in the opening / closing device for the original cover provided with the fluid damper device 52, the oil damper of the fluid damper device 52 is small enough to be housed inside the compression coil spring 48. It is a unit that incorporates oil and a diaphragm in a cylinder that has been made into a unit, which not only increases the cost, but also operates with a small stroke at a closing angle of the original cover 49 of at most 10 to 20 ° or less. In other words, the closing angle region of the original cover 49 where the damper function can be obtained is extremely limited and narrow, and it is impossible to prevent a sharp drop from a closing angle larger than the closing angle of the original cover 49, so that safety is reduced. Low. In particular, such a problem occurs remarkably in the case of a heavy document pressure plate having an automatic document feeder (ADF). An object of the present invention is to solve such a problem, and it is possible to improve the safety by enabling the damper function to be exerted over the entire closing process of the original cover. An object of the present invention is to provide an original document pressing plate opening / closing device capable of reducing the cost of a damper device. According to the present invention, there is provided an attaching member (5) attached to the apparatus body (1) side, and a rear end of the attaching member (5) is vertically connected to the attaching member via a hinge pin (6). A support arm (7) of a document pressure plate (2) rotatably connected to the document pressure plate (2), and a document pressure plate (2) with the support arm attached thereto between the support arm and the mounting member. A) a compression coil spring (16) mounted so as to be urged in the opening direction against the moment in the closing direction due to the weight of (1); A slider (15) slidably mounted in the direction of movement, between the hinge pin and the slider, with the opening and closing rotation of the document pressing plate and the support arm around the hinge pin. Retreat / forward In an opening / closing device for a document pressing plate provided with a support arm cam mechanism (19) to be moved, a damper device (2) is provided between the support arm and the slider.
4) is provided, and this damper device is configured as follows. In other words, the damper device includes a damper base (27) fixed to the support arm and having a groove (25) and a ridge (26) elongated in the front-rear direction on the lower surface arranged alternately in the left-right direction. A ridge (28) and a groove (29) arranged on the upper surface of the slider so as to be slidably fitted to the groove and the ridge, and a sliding surface between the lower surface of the damper base and the upper surface of the slider. And a grease (30) interposed therebetween. According to the opening / closing device for the original cover, the slider is moved forward by the support arm cam mechanism when the original cover is closed from the fully opened state. The ridges and grooves on the upper surface of the slider slide through the grease with respect to the ridges, thereby exhibiting a damper function.This damper action prevents a sudden drop due to the moment in the closing direction due to the weight of the original cover, Even when the original cover is heavy, the falling speed is reduced and the document is closed slowly. Such a damper function is exerted over the entire closing process from the fully opened state to the fully closed state of the original cover, so that the damper function can be obtained only in a very limited closing angle region of the original cover. Compared with the original, the original cover can be prevented from dropping abruptly in a wide opening area, and safety can be improved. [0007] The surface area of the grease layer can be increased by grooves and projections which are fitted into and recessed from each other between the sliding surface between the lower surface of the damper base and the upper surface of the slider, thereby further increasing the damper effect. Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional side view showing a document pressing plate opening / closing device according to an embodiment of the present invention in a fully closed state, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG.
4 is a vertical sectional side view showing the original cover pressing apparatus of FIG. 1 in a fully opened state, and FIG. 5 is a vertical sectional side view of the original cover open / close apparatus of FIG. 1 in a thick original pressing state. In FIG. 1, reference numeral 1 denotes an apparatus main body such as a copying machine;
Reference numeral 2 denotes a document pressure plate, and reference numeral 3 denotes a document pressure plate opening / closing device in which the document pressure plate 2 is attached to the apparatus main body 1 so as to be openable and closable vertically. The document pressing plate opening / closing device 3 includes a mounting member 5 that is mounted on the apparatus main body 1 with screws or the like, and the mounting member 5.
And a support arm 7 whose rear end is pivotally connected in a vertically rotatable manner via a hinge pin 6. In the illustrated example, the support arm 7 further has a front end supported by a front end. There is provided a lift arm 11 pivotally connected via a pin 9 so as to be vertically rotatable. Lift arm 11
Is attached to the rear end side of the original cover 2 with screws or the like (not shown). The mounting member 5 includes a metal bottom plate 5a which is mounted on the apparatus main body 1 with screws or the like, side plates 5b, 5b raised from both left and right ends of the bottom plate 5a, and a rear end of the bottom plate 5a. And a rear plate 5c. On the other hand, the support arm 7 includes a metal upper plate 7a, and both side plates 7 bent downward from both left and right ends of the upper plate 7a.
b, 7b, and lip 7c, 7c which is bent inward from the both side plates 7b, 7b in parallel with the upper plate 7a, respectively. The rear ends of both side plates 7b, 7b of the support arm 7 are pivotally connected to both side plates 5b, 5b of the mounting member 5 via hinge pins 6 so as to be vertically rotatable. As shown in FIGS. 1 and 2, the lift arm 1
Reference numeral 1 denotes a cross section having a metal upper plate 11a attached to the rear end side of the original cover 2 with screws or the like (not shown), and both side plates 11b, 11b bent downward from both left and right ends of the upper plate 11a. It is formed in a groove shape. The upper arm 11 a of the lift arm 11 is different from the upper arm 7 a of the support arm 7 with respect to the support arm 7.
On both sides of the supporting arm 7, the both side plates 11 b, 11 b are overlapped with the outside of the both side plates 7 b, 7 b of the support arm 7, respectively, and the front end of the lift arm 11 is vertically moved around the support pin 9 on the front end side of the support arm 7. It is pivotally connected to be rotatable. As shown in FIGS. 1 to 3, on the lips 7c, 7c between the side plates 7b, 7b of the support arm 7, a bottomed cylindrical member made of a polyacetal resin or a polyamide resin having excellent wear resistance is provided. The spring receiver 14 and the slider 15 are formed in front and rear, and are respectively slidably assembled in the front and rear direction. The slider 15 in the support arm 7
A compression coil spring 16 for urging the support arm 7 to rotate in the opening direction against the moment in the closing direction due to the weight of the original cover 2 attached thereto is interposed between the spring arm 14 and the spring support 14. As shown in FIG. 1, a support arm cam mechanism 19 is provided between the slider 15 and the hinge pin 6. The support arm cam mechanism 19 is provided on both side plates 5 of the mounting member 5.
b, 5b, a cam 17 fixed by a hinge pin 6 and a fixing pin 12 arranged parallel to the hinge pin 6 so as to be lower and forward of the hinge pin 6 and integral with the rear side of the slider 15. And a cam follower 18 provided at the center. The cam 17 has a small-diameter arc portion 17a formed at the lower portion of the outer peripheral edge so as to be closest to the axis of the fixing pin 12, and gradually moves upward from the axis of the fixing pin 12 upward from the upper end of the small-diameter arc portion 17a. It is formed in a shape having a gentle curved edge portion 17b formed so as to go away. Thus, the support arm cam mechanism 19 allows the cam follower 18 to move the small-diameter arc portion 1 of the cam 17 near the fully closed angle of the original cover 2.
7a, the slider 15 is pressed in the direction of compressing the compression coil spring 16 and moved forward to move the original pressing plate 2
Is gradually opened, the cam follower 18 slides on the gentle curved edge portion 17b to move the slider 15 backward so as to extend the compression coil spring 16 gradually longer. As shown in FIG. 1, between the spring support 14 and the front end of the lift arm 7, a lift cam 20 is formed by projecting a pin-shaped protrusion 20a of polyacetal resin or polyamide resin so as to protrude backward. But protrusion 2
The lift arm 11 is fixed with screws or the like between the side plates 11b, 11b on the front end side so that the reference numeral 0a is located below the support pin 9. On the back side of the spring receiver 14, a slope projection 21 is formed, with which the projection 20a of the lift cam 20 abuts. When the lift arm 11 overlaps the support arm 7, the protrusion 20a of the lift cam 20 is in contact with the slope protrusion 21 of the spring receiver 14, and as shown in FIG. The original document P is placed on the contact glass 23 of the apparatus main body 1, the original cover 2 is closed, a part of the original cover P is applied to the thick original P, and the front side of the original cover 2 is pressed slightly downward. The lift arm 11 pushes the spring receiver 14 while sliding on the slope projection 21 of the spring receiver 14 with the projection 20a of the lift cam 20, and the compression coil spring 16 is slightly compressed, and the support pin is pressed against its elasticity. It turns around 9 in the direction of arrow M. Due to this reversal, the original cover 2 is lifted up at the rear end side so as to be parallel to the upper part of the thick original P, and the entire thick original P is pressed on the contact glass 23 with uniform pressure. The present invention is characterized in that a damper device 24 is provided between the support arm 7 and the slider 15, as shown in FIGS. The damper device 24 includes a damper base 27 fixed to the support arm 7 and having grooves 25 and ridges 26 long in the front-rear direction on the lower surface arranged alternately in the left-right direction.
A ridge 28 and a groove 29 arranged on the upper surface of the slider 15 so as to slidably fit with the groove 25 and the ridge 26;
The grease 30 has a high consistency interposed between sliding surfaces between the lower surface of the damper base 27 and the upper surface of the slider 15. The ridges 26 and 28 and the grooves 25 and 29 have the lowest ridges 26 and 28 near the center in the left-right direction and the grooves 25 and 29.
Is the shallowest, and the ridges 26, 28
Are formed along the upper part of the circumference of the spring receiving hole inside the slider 15 so that the grooves 25 and 29 gradually become deeper. In addition, as shown in FIG.
The upper surface of 4 is formed in such a shape that it can lightly contact the ridge 26 near the center in the left-right direction of the damper base 27. According to the opening / closing device of the original cover in the above-mentioned configuration, when the original cover 2 is fully closed in the horizontal position as shown in FIG.
And the magnitude of the moment in the closing direction caused by the weight of the original cover 2 and the magnitude of the moment in the opening direction due to the elastic force of the compression coil spring 16 are balanced. , And the fully closed state of the original cover 2 is maintained. When the original cover 2 is opened from the fully closed state, the compression coil spring 16 which urges the support arm 7 in the opening direction against the moment in the closing direction due to the weight of the original cover 2 is opened. While the slider 15 moves backward through the support arm cam mechanism 19 due to elasticity, the original cover 2 gradually opens greatly. When the original cover 2 and the support arm 7 are fully opened (for example, 60 °) as shown in FIG. 4, the slider 15 is at the most retracted position. When closing the original cover 2 from the fully opened state, the slider 15 moves forward through the support arm cam mechanism 19, and the slider 1
By sliding the protrusions 28 and grooves 29 on the upper surface of 5 through the grease 30 with the grooves 25 and protrusions 26 on the lower surface of the damper base 27, a damper function is exhibited. By this damper action, it is possible to prevent a sudden drop due to the moment in the closing direction due to the weight of the original cover 2, and even if the original cover 2 is heavy, the original is slowly closed at a reduced falling speed. Therefore, it is possible to prevent an accident such as pinching of the hand between the original cover 2 and the contact glass 23. Such a damper function is exerted over the entire closing process from the fully opened state of the original cover 2 to the fully closed state, so that the original cover 2 does not drop suddenly from any open angle position, and safety is improved. It was expensive.
In addition, the surface area of the grease layer can be increased by the grooves 25 and the ridges 28 and the ridges 26 and the grooves 29 which are fitted into and recessed from each other between the sliding surface between the lower surface of the damper base 27 and the upper surface of the slider 15. Could be raised further. In the apparatus for opening and closing the original cover in the above embodiment, the lift arm 11 is provided to cope with a thick original. However, the present invention does not include the lift arm 11 but includes the support arm 7 and the mounting member 5. The present invention can be similarly applied to an opening / closing device for an original pressing plate. However, in this case, the original cover 2 is attached to the support arm 7, the spring receiver 14 is fixed to the support arm 7, and the lift cam mechanism 22 becomes unnecessary. According to the present invention, the action of the damper device provided between the support arm and the slider causes not only a sharp drop from the small opening angle position of the original cover but also a large opening angle position. Can be prevented from falling sharply, so that safety can be improved. The damper device is
Since the damper base is formed by arranging the grooves and the ridges, the ridges and the grooves are arranged on the upper surface of the slider so as to be fitted with the grooves and the ridges, and the grease is used.
There is an advantage that the damper effect can be enhanced and that it can be provided at a lower cost than a fluid damper device including a conventional oil damper unit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional side view showing a document pressing plate opening / closing device according to an embodiment of the present invention in a fully closed state. FIG. 2 is a sectional view taken along line AA in FIG. FIG. 3 is a sectional view taken along line BB in FIG. 1; FIG. 4 is a vertical sectional side view showing the document pressing plate opening / closing device of FIG. 1 in a fully opened state. FIG. 5 is a longitudinal sectional side view showing the original document pressing plate opening / closing device of FIG. 1 in a state where a thick original document is pressed. FIG. 6 is a vertical cross-sectional side view showing a conventional document pressing plate opening / closing device in a fully closed state. FIG. 7 is a longitudinal sectional side view showing the document pressing plate opening / closing device of FIG. 6 in a fully opened state. DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Original pressure plate 5 Mounting member 6 Hinge pin 7 Support arm 15 Slider 16 Compression coil spring 19 Support arm cam mechanism 24 Damper device 25 Damper base groove 26 Damper base ridge 27 Damper base 28 Slider Ridge 29 slider groove 30 grease

Claims (1)

Claims 1. An attachment member attached to an apparatus main body, and a document pressure plate having a rear end pivotally connected to the attachment member via a hinge pin so as to be rotatable in a vertical direction. The support arm is mounted between the support arm and the mounting member so as to bias the support arm in the opening direction against the moment in the closing direction due to the weight of the original cover attached to the support arm. A compression coil spring, and a slider incorporated in the support arm so as to receive the rear end of the compression coil spring and to be slidable in the front-rear direction, and between the hinge pin and the slider. An opening / closing device for an original cover provided with a support arm cam mechanism for retracting and moving the slider in accordance with the opening and closing rotation of the original cover and the support arm around the hinge pin. A damper device is provided between the support arm and the slider, and the damper device is provided with a long groove extending in the front-rear direction and a ridge on the lower surface alternately arranged in the left-right direction. A damper base, a ridge and a groove arranged on the upper surface of the slider so as to be slidably fitted to the groove and the ridge, and a sliding between a lower surface of the damper base and an upper surface of the slider. An opening / closing device for an original cover, wherein the opening / closing device is made of grease interposed between surfaces.