Device for attaching and detaching roller, and belt conveyor including the device

A device for attaching and detaching, as a detachable roller, at least one of a plurality of rollers in a belt conveyor in which an endless belt is wound around the plurality of rollers arranged between a front plate and a rear plate of the belt conveyor, the device comprising:

• a guide having a base end to be supported by the rear plate on a rear side of the device, the guide extending along a longitudinal direction of the detachable roller from the rear side to a front side of the device, when the base end is supported by the rear plate, the guide including a guide groove extending in the longitudinal direction of the detachable roller;
• and
• a roller holder including:
• an engagement portion to detachably engage with the front plate;
• another engagement portion to detachably engage with the rear plate;
• and
• a guided portion to slide along the guide groove of the guide toward the rear side or the front side of the device to engage or disengage the engagement portion with or from the front plate and engage or disengage said another engagement portion with or from the rear plate.