Abstract: A chain assembly includes interconnected chain units each having two rollers, two bushings disposed through the rollers, two inner plates rotationally disposed on the bushings, and two pins penetrating the bushings and the inner plates. Two outer plates are rotationally fixed to respective pins between adjacent inner plates. Each inner plate has two inner pin holes, two rims projecting from one surface of the inner plate, and a contact area formed around the rims. Each outer plate has two outer pin holes, two accommodation portions protruding from one surface of the outer plate to provide two rooms formed into opposing surface thereof, and a positioning area formed around the rooms for fitting snugly with adjacent contact areas when the respective rims are completely covered by the rooms. Therefore, the structure strength is increased, the transmission is stable and smooth, and no entry and accumulation of dust is incurred.

Abstract: A leaf chain includes a plurality of chain units each having two pins, around which first and second alternate inner plates between outer plates are mounted. The plates form respective apertures where the pins penetrate. Each chain unit has bushings located in the apertures of the first and second inner plates, and first washers disposed between any two adjacent bushings and between the bushings and the outer plates. There are connecting plates located at an outer side of the outer plates and tightly engaged with the pins to prevent the outer plates from being deformed because of a concentration of large force in the outer plates during the transmission. The outer plates have a loose engagement with the pins to prevent the pins and inner plates from being worn away. The first washers help the sealing effect to maintain the preferable stability and transmissibility and prolong the operating life.

Abstract: A conveying chain comprises a plurality of chain sets connected together, each chain set comprises a chain bush, inner plates and outer plates respectively disposed on both sides of the chain bush, and a pin member penetrating the chain bush and connecting the inner and the outer plates, wherein a plurality of openings are defined at intervals on a circumference of the chain bush. A through hole is communicated with an outside via the openings, so that dust or exterior impurities accumulated between the chain bush and the pin member can be outwardly discharged through the openings to prevent the accumulation of the dust or impurities from having an adverse influence on the transmission of the chain and to increase the smoothness of the chain operation and the use duration efficiently.

Abstract: A leaf chain comprises a plurality of links connected together, each of which includes two aligned rollers, at least one first inner plate provided with apertures to pivotally receive the rollers, and two outer plates fixed to the respective rollers and respectively positioned at external sides of the first inner plate. Wherein, two spacers are respectively disposed at both peripheries of the aperture on the first inner plate and annularly disposed on the rollers so as to block a leakage of a lubricant distributed over an interstice formed between each roller and each aperture.