Abstract: A loose-leaf binder comprises a back and a loose-leaf coil. The back comprises a lower sheet and an upper sheet. Each side of the back is formed with a track having a downward opening. At least one end of the back is formed with an open end portion. Each lateral side edge of the lower sheet is formed with a slightly upwardly projecting flange. The lower sheet is formed with at least one engaging slot corresponding to the open end portion of the flange. The loose-leaf coil to be selectively disposed below the back is formed with continuous C-shaped portions by bending a wire. Each end of each C-shaped portion is formed with a track section to slide in the track of the back. The track section can be selectively engaged and restricted within the engaging slot of the lower sheet of the back.

Abstract: A loose-leaf binder device comprises a back, two end plugs that can selectively close two ends of the back, and a loose-leaf coil for binding inner pages and selectively disposed below the back. The back is formed with an insert slot. A retaining hole communicating with the insert slot is formed on a portion of the back abutting upon an end edge. The end plug is integrally formed with a resilient member to be inserted into the insert slot. A top surface of the resilient member is formed with one post corresponding to the retaining hole of the back. A free end of the resilient member is formed with an upward compressing edge. Thus, the post on the resilient member can be actuated through a compressing edge according to the resilient member of the end plug so that the post is selectively engaged with or disengaged from the back.

Abstract: A loose-leaf binder has a back, a binder made of a flexible material and attached to the back and two end plugs mounted respectively in ends of the back. The back has two tracks, two side slots and a middle slot. The binder has multiple open rings having two ends. Each plug has two side tines and a middle tine. A notebook with the loose-leaf papers can be easily attached to or detached from the loose-leaf binder by attaching or detaching the open rings of the binder to punched holes in the notebook simultaneously.

Abstract: A binding device for holding loose-leaf papers comprises a binder folded by a flexible material to form of a plurality of openings each constructed by two circumferential hooks, an engageable strip and two ended envelopes. The binder passes through a number of holes punched on each loose-leaf paper and the openings are faced outwardly. The longitudinal strip has two parallel longitudinal slots for corresponding to the hooks of the binder so that the binder can be engaged with the engageable strip. After that, the ended envelopes envelop on either end of the strip to prevent the strip from sliding.