A conveyor includes a track and a grip unit. The grip unit includes a main body having a slide groove that receives slidably the track, a push piece provided on the track at a predetermined position and having a pushing surface to face the slide groove, a push rod inserted movably into the slide groove to abut against the pushing surface, a resilient restoring element for biasing the push rod upwardly, two grip arms connected pivotally to the main body and disposed respectively on two opposite sides of the push rod, and two spring members each disposed between the main body and a respective grip arm to bias one grip arm toward the other grip arm so that the grip arms cooperate with each other to grip an object therebetween. The push rod is movable downwardly to push the object when the push rod abuts against the pushing surface.