especially used the closing device has the spring case made of a synthetic resin provided for either an attaching member attached to a machine body or a supporting member for holding the original cover rotatably connected to the attaching member via a hinge pin and the rotation moment of the original cover attached to the supporting member is controlled by using a compression force of a compression coil spring housed in the spring case wherein a reinforcing frame member made of a metal for reinforcing the spring case is attached to the spring case application_number US 7653698 A description the following drawings show an embodiment of an original cover closing device a according to the invention in fig1 to 5 reference numeral 1 denotes an attaching member having a leg 2 by detachably inserting the leg 2 into an insertion hole 3a opened in a rear upper end of the body of for example a copy machine shown by imaginary lines the closing device is mounted on the machine body 3 although a use example of the leg 2 is not shown in the diagram for example when an original is a thick original such as a book by lifting the position of the insertion hole 3a.