Single-detent binder
A single-detent binder for a file folder has a housing, one pair of baseplates, ring shaped components, a control component, a pull rod, rotary locking pieces and an intermediate junction component. The control component, intermediate junction component, pull rod and rotary locking pieces are connected in series. When the control component rotates, the rotary locking pieces are triggered to rotate in the trough of the first baseplate based on the mechanical principle of connecting rod, thus performing the locking/unlocking function. When the binder is closed, the baffle plates on the second baseplate hinder the rotary locking pieces from rotation, thus generating a clamping force. After the baffle plates and rotary locking pieces work jointly to close the binder, the ring shaped components generate a scrambling force, thus enhancing the locking effect and preventing the single-detent binder from opening unexpectedly.