Hinge device

A hinge device for connecting a document press-contacting plate to a body side of an apparatus body, comprising:

• an attachment member having a pair of attachment member side plates at a distance from each other, the attachment member being adapted to be attached on the apparatus body on the body side;
• a supporting member having a pair of supporting member side plates pivotally attached by a first hinge pin to the attachment member side plates, the supporting member side plates each having a free end spaced from the first hinge pin;
• a lifting member adapted to be connected to the document press-contacting plate and being pivotally attached by a second hinge pin to the free ends of the supporting member side plates;
• a first spring case housed in said supporting member and swingably attached by a third hinge pin to the free ends of the supporting member, the third hinge pin being positioned at the body side of the apparatus body and being spaced from the second hinge pin;
• a second spring case compressibly fitted to the first spring case and having a base portion that is swingably attached by a fourth hinge pin to the attachment member, the fourth hinge pin being positioned at the body side of the apparatus body and being spaced from said first hinge pin, the base portion of the second spring case having an attachment hole;
• a damper having a fixing side and a cylinder, the cylinder having one end inserted and fixed into the attachment hole of the base portion of the second spring case, the damper having a male screw portion on the fixing side;
• an adjustment plate screwed to the male screw portion of the damper;
• and
• at least one compression spring with said damper being housed therein and being elastically provided between the adjustment plate and an inside top portion of said first spring case.