A medium conveying apparatus includes a feed roller to feed a medium, a separation roller opposed to the feed roller, a motor to generate driving force by being supplied with electric power, a cam member rotated in a first direction by the driving force to press the separation roller toward the feed roller, and a driving force transmitting mechanism between the motor and the cam member, the driving force transmitting mechanism being configured to transmit the driving force from the motor to the cam member and provided such that the cam member keeps pressing the separation roller toward the feed roller without rotating the cam member in a second direction opposite to the first direction even if electric power supply to the motor is shut off.

The present disclosure provides a multi-filament helical winding device. The device includes a frame, a multi-filar guide radial telescopic portion, a multi-filar guide rotation portion. The multi-filar guide radial telescopic portion and the multi-filar guide rotation portion are arranged on the frame, and the multi-filar guide radial telescopic portion is connected to the multi-filar guide rotation portion. A count of the multi-filar guide radial telescopic portion is the same as a count of the multi-filar guide rotation portion, and the multi-filar guide radial telescopic portion corresponds to the multi-filar guide rotation portion one by one. The multi-filar guide radial telescopic portion includes a first telescopic mechanism or a second telescopic mechanism. The multi-filar guide rotation portion includes a first rotation mechanism or a second rotation mechanism.

A strap roller contains: a frame, a fixing post, a central shaft, a worm gear, a rotation element, a support rack, a worm, a manual crank, a cap, and a resilient locking spring. The frame includes a first fence and a second fence. The fixing post is defined between the first fence and the second fence. The central shaft is rotatably connected between the first fence and the second fence. The worm gear is fitted on the central shaft. The rotation element is fixed on the central shaft. The support rack is mounted on the frame and is located outside the first fence. The worm includes a first extension portion, a second extension portion, and a tooth portion. The manual crank is connected on the first extension portion. The cap is disposed on the first fence of the frame. The resilient locking spring is mounted on the cap.

A medium conveying apparatus includes a feed roller to feed a medium, a guide to restrict contact between the medium and the feed roller, a moving mechanism to move the guide, a driving source, and a drive transmission assembly to transmit a driving force for moving the guide from the driving source to the moving mechanism. The drive transmission assembly applies a load to the moving mechanism, and the load restricts transmission of force from the guide to the driving source.

A manual winding device comprises a wire bracket, a clamp, a winder, and a tension maintainer. The wire bracket supplies wire, while the clamp holds it in place. The winder, adjacent to the clamp, includes a driving mechanism and a coil former holding unit. The coil former holding unit is configured to mount a coil former. The driving mechanism is configured to drive the coil former holding unit to rotate, winding the wire onto the coil former. The tension maintainer, located between the clamp and the winder, includes a sliding base, a sliding block, and four connecting rods forming a quadrilateral. The sliding block is movably disposed on the sliding base. Two opposite connection points are pivotally mounted on the base and sliding block, while the other two points each hold a pulley around which the wire passes. The tension maintainer ensures the wire's tension is maintained during winding.