In some aspects, a conveyor chain includes a first link, a second link, and a coupler link coupled between the first link and the second link. The first link includes a first portion and a second portion, the second portion oriented parallel to and laterally spaced apart from the first portion. The first portion includes a first sprocket-engaging pin protruding laterally, and the second portion includes a second sprocket-engaging pin protruding laterally. The second link includes a first portion and a second portion. The first portion includes a first sprocket-engaging portion protruding laterally, and the second portion includes a second sprocket-engaging portion protruding laterally. A flight bar is positioned adjacent an end of the first sprocket-engaging portion of the first link.

A linkage for moving material from a first end of a conveyor toward a second end of the conveyor includes a first link and a second link. The first link includes a first side edge and a first indicator. The second link includes a second side edge and a second indicator. The second link is coupled to the first link such that the first side edge of the first link overlaps with the second side edge of the second link. Elongation of the first link in the direction of movement causes the first indicator to move relative to the second indicator, and a position of the first indicator relative to the second indicator provides an indication of a wear condition of the first link. In some aspects, a first surface and/or a second surface of one of the links includes a wear indicator representing a surface wear condition.

A drive mechanism for a chain conveyor includes an elongated shaft that extends along an axis and is configured to be driven to rotate by a motor. A sprocket is integrally formed with the shaft. The sprocket includes a plurality of lobes that extend around a perimeter of the shaft. Each lobe is spaced apart from an adjacent lobe by a recessed portion. Each of the recessed portions is configured to receive a drive pin of the chain conveyor.

A stockyard joint reclaiming system includes an outer output conveyor, a scraper reclaimer provided with a scraper mechanism, an inner feeder, and an inner output conveyor arranged below a stockpile. The scraper mechanism includes a chain and a scraper installed on a chain. The chain moves forwards or backwards under the action of a driving device to drive the scraper to push materials to a corresponding discharging port. The scraper mechanism drives the scraper through forward or reverse operation of the chain for pushing the materials to the output conveyor and a reclaiming line can be selected. A reclaiming mode is flexible and more output lines are available. When the material level is lower than a horizontal position, the scraper is driven to move through a reverse operation of the chain to push the materials to an upper part of the inner feeder for realizing reclaiming, thereby reducing unnecessary energy consumption and effectively guaranteeing the reclaiming capability of the scraper reclaimer.