Abstract: In a binding assembly for binders for holding a number of sheets of paper detachably bound together, the clamping unit, which includes a pair of metallic clamping plates for holding the paper therebetween, is detachably latched to a holder base which is in turn permanently attached to the binding of a binder. The clamping unit is provided with a bar extending across a cutout provided in a lower edge of each clamping plate, and the bar latches onto a latching mechanism provided in the holder base. Either one of the clamping plates may be selectively latched onto or unlatched away from the holder base while the other clamping plate is kept hinged to the holder base. The latching mechanism includes a pair of latch members made of plastic material, and slidably retained by a metallic base plate of the holder base, and the load applied to the clamping unit is primarily supported by the metallic base plate for minimizing the load applied to the latch members.

Abstract: An opening/closing device for a pipe file binder comprising a base, a pair of cover plates pivotally mounted on opposite longitudinal side portions of the base such that the cover plates can be opened and closed, the cover plates each being provided with an opening portion formed in a generally central portion thereof, a resilient member located between the cover plates on the base, a pair of levers provided on generally central portions of outer sides of the cover members and inserted in the opening portions, respectively, and by pressing the levers, a part of an outer side portion of the resilient member being disengaged from a part of an outer side portion of the base so that the cover plates are opened and disengaged.