Patent Publication Number: US-7900320-B2

Title: Opening/closing device for document pressing device

Description:
TECHNICAL FIELD 
     The present invention relates to an original cover closer for use in a copying machine, a facsimile machine, a scanner or a multifunctional device thereof and the like. 
     BACKGROUND ART 
     A conventional type of this cover closer includes a mounting member which is mounted to the main body of a copying machine, a supporting member which is pivotally mounted on the mounting member and supporting an original cover, and a compression coil spring which is placed between the mounting member and the supporting member and urged in the direction to open the original cover (for example, refer to Japanese Patent Published Application No. 2006-010979). 
     However, in the above conventional original cover closer, the compression coil spring is exposed outside. Thereby, particularly when the cover closer is opened, there are problems in that an original document may touch the spring and be stained and tainted with oil, that some foreign object may be caught by the compression coil spring to cause damage and so forth. 
     In addition, in the above conventional original cover closer, there are problems in that it is not easy to adjust the compression amount of the compression coil spring and so forth. 
     It is an object of the present invention to provide an original cover closer in which a compression coil spring can stably and surely work, the original cover can expeditiously and smoothly be operated, and the compression amount of the compression coil spring can be set and changed in an extremely easy manner. 
     SUMMARY OF THE INVENTION 
     The original cover closer in accordance with the present invention comprises: a mounting member mounted to the main body of a copying machine; a supporting member pivotally mounted to the mounting member and operable to support the original cover; a first slider and a second slider which are slidably installed in the supporting member; and a compression coil spring inserted between these sliders and operable to urge the original cover in the direction to open, wherein at least one of the sliders is formed integrally with a spring cover which covers the compression coil spring even when the original cover is opened. Alternatively, the cover closer is characterized by a mounting member mounted to the main body of a copying machine; a supporting member pivotally attached to the mounting member and operable to support the original cover; a first slider and a second slider which are slidably installed in the supporting member; and a compression coil spring inserted between these sliders and operable to urge the original cover in the direction to open, wherein at least one of the sliders is assembled with a mechanism for adjusting the compression amount of the compression coil spring. Furthermore, the device is characterized in that the mechanism for adjusting the compression amount of the compression coil spring is installed between the compression coil spring and said at least one of the sliders and implemented with a spring regulation member which is threaded with this slider. 
     In accordance with the original cover closer of the present invention, there are advantages that the compression coil spring can stably and surely work, the original cover can expeditiously and smoothly be operated, and the compression amount of the compression coil spring can be set and changed in an extremely easy manner. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional side view for showing an embodiment of the original cover closer in accordance with the present invention. 
         FIG. 2  is a view for explaining the main portion as seen from the direction of arrow A in  FIG. 1 . 
         FIG. 3  is a cross sectional side view for showing the device of  FIG. 1  which is closed. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     In  FIG. 1  and  FIG. 2 , an original cover P is mounted to the main body M of a copying machine or the like through a cover closer H such that it can be freely opened and closed. The above cover closer H is composed mainly of a mounting member  1  which is mounted to the main body M, a support arm  3  which is pivotally attached to the mounting member  1  through a hinge shaft  2 , and a lift arm  5  which is pivotally attached to the end of the support arm  3  through a support shaft  4  and to which the original cover P is fixedly attached. 
     A first slider  6  and a second slider  7  are disposed in the support arm  3  such that they can slidably move in the longitudinal direction, and a compression coil spring  8  is inserted between the first and second sliders  6  and  7 . The cam follower  6   a  of the first slider  6  abuts on an abutment portion  5   a  of the lift arm  5 , and the cam follower  7   a  of the second slider  7  abuts on a cam portion  9  which is provided of the mounting member  1 . 
     Incidentally, the cover closer H according to the present invention is not limited to the structure as described above, but can be any one of known structures, for example, a structure in which the support shaft  4  and the lift arm  5  are not used and the original cover P is fixedly attached to the support arm  3 . 
     The first slider  6  is integrally formed with a spring cover  10  which serves to protect the compression coil spring  8  by covering and hiding it. The spring cover  10  may be provided as a separate element from the first slider  6 , and integrally attached and fixed to the first slider  6 . As illustrated in  FIG. 3 , at least when the support arm  3  rotates in the closing direction so that the first slider  6  and the second slider  7  move toward each other (i.e., the compression coil spring  8  is compressed), the first slider  6  slides to overlap the second slider  7  at the spring cover  10  from the outside in order not to interfere with each other. 
     A spring regulation member  11  is installed between the compression coil spring  8  and the second slider  7 . The cylindrical section of the spring regulation member  11  is externally threaded to screw with the thread externally formed around the cylindrical section of the second slider  7 . Accordingly, the spring regulation member  11  moves toward or away from the second slider  7  by rotating it, and as a result the compression coil spring  8  is expanded or contracted to change the compression amount thereof, i.e., the repulsive force. 
     A plurality of holes  11   a  are formed all the way around the spring regulation member  11  at equal intervals as a means for rotating the spring regulation member  11 , and an opening  7   b  is formed through the second slider  7  so that the holes  11   a  can be externally accessed. The opening  7   b  is sized in order that at least two of the holes  11   a  can be accessed, and hence the adjustment can be performed by inserting an appropriate pin (not shown in the figure) into the hole  11   a  and repeatedly rotating the spring regulation member  11  bit by bit. 
     While the present invention has been described in terms of embodiments, it is apparent to those skilled in the art that the invention is not limited to the embodiments described. The present invention can be practiced with modification and alteration within the spirit and scope of the appended claims. The description is thus to be regarded as illustrative instead of limiting in any way on the present invention.