Problem. To provide a chain pin which makes it possible to improve wear resistance even in an environment in which degraded oil is used. Solution. A large number of pins are mixed/agitated together with a particle mixture including a penetrant comprising chromium (Cr) powder and tungsten carbide (WC) powder, and an iron chloride (FeCl.sub.3) catalyst, and WC particles penetrate the surface of the pins together with chromium carbide (CrC). As a result, a chromium carbide layer in which WC particles are diffused in a CrC layer (CrCWC layer) is formed on the outermost surface part of the steel forming the parent material of the pins.

Problem. To provide a chain pin which makes it possible to improve wear resistance even in an environment in which degraded oil is used. Solution. A large number of pins are mixed/agitated together with a particle mixture including a penetrant comprising chromium (Cr) powder and tungsten carbide (WC) powder, and an iron chloride (FeCl.sub.3) catalyst, and WC particles penetrate the surface of the pins together with chromium carbide (CrC). As a result, a chromium carbide layer in which WC particles are diffused in a CrC layer (CrCWC layer) is formed on the outermost surface part of the steel forming the parent material of the pins.

A chain including chain-link units pivotally connected with each other. Each chain-link unit includes two lateral plates, a first link plate and a second link plate. Two ends of the lateral plates are defined as a first end and a second end. Two first pin-joint parts are configured near the first ends of the lateral plates respectively, and two second pin-joint parts are configured near the second ends of the lateral plates respectively. The chain-link units are pivotally connected with each other via the first pin-joint part and the second pin-joint part. Thus, the chain-link units are common, and each can be the starting chain-link unit, the middle chain-link unit or the ending chain-link unit. They can be easily assembled without screws, which further reduce the time consumption. Moreover, the noise made as the chain works can be reduced, and a buffering function can also be provided.

A chain including chain-link units pivotally connected with each other. Each chain-link unit includes two lateral plates, a first link plate and a second link plate. Two ends of the lateral plates are defined as a first end and a second end. Two first pin-joint parts are configured near the first ends of the lateral plates respectively, and two second pin-joint parts are configured near the second ends of the lateral plates respectively. The chain-link units are pivotally connected with each other via the first pin-joint part and the second pin-joint part. Thus, the chain-link units are common, and each can be the starting chain-link unit, the middle chain-link unit or the ending chain-link unit. They can be easily assembled without screws, which further reduce the time consumption. Moreover, the noise made as the chain works can be reduced, and a buffering function can also be provided.

An anti-backbend chain comprises a plurality of alternate chain links joined by respective chain hinges, a spring element comprising at least a first spring arm being provided. The spring element rests on a chain hinge and the first spring arm extends to a neighbouring chain hinge and is movably in contact therewith under the biasing force of the spring element, so as to obstruct bending of the anti-backbend chain in a first pivot direction. In addition, an anti-backbend chain drive is provided, in particular a chain drive for driving automated door or gate systems.

An anti-backbend chain comprises a plurality of alternate chain links joined by respective chain hinges, a spring element comprising at least a first spring arm being provided. The spring element rests on a chain hinge and the first spring arm extends to a neighbouring chain hinge and is movably in contact therewith under the biasing force of the spring element, so as to obstruct bending of the anti-backbend chain in a first pivot direction. In addition, an anti-backbend chain drive is provided, in particular a chain drive for driving automated door or gate systems.

An energy chain and storage unit for an energy chain having a first chain portion and a second chain portion each including pivotable chain links with upper and lower narrow surfaces, and two side parts (6, 7). At least some of the chain links (2) of the first chain portion (3) have guide elements (12), which project outwards from the side parts (6, 7) allowing the chain links to guide on guide tracks (35), arranged on the outside of the chain links, and at least some of the chain links (4) of the second chain portion (5) have roller elements (13) or sliding elements (14), which project laterally beyond the upper or the lower narrow surfaces (8) of side parts (6, 7) of the chain links and can respectively roll or slide on a region which is located opposite said narrow surfaces (8).

An energy chain and storage unit for an energy chain having a first chain portion and a second chain portion each including pivotable chain links with upper and lower narrow surfaces, and two side parts (6, 7). At least some of the chain links (2) of the first chain portion (3) have guide elements (12), which project outwards from the side parts (6, 7) allowing the chain links to guide on guide tracks (35), arranged on the outside of the chain links, and at least some of the chain links (4) of the second chain portion (5) have roller elements (13) or sliding elements (14), which project laterally beyond the upper or the lower narrow surfaces (8) of side parts (6, 7) of the chain links and can respectively roll or slide on a region which is located opposite said narrow surfaces (8).

A chain is made of an iron-based material and includes multiple pairs of outer plates and multiple pairs of inner plates. The chain includes a base film that contains zinc and is formed on the surface of the chain, and a coating film that contains lithium silicate and sodium silicate and is formed on the base film. The mass ratio of the mass of the active ingredient of the lithium silicate to the mass of the active ingredient of the sodium silicate is in a range of 0.07 to 2.5.

A chain is made of an iron-based material and includes multiple pairs of outer plates and multiple pairs of inner plates. The chain includes a base film that contains zinc and is formed on the surface of the chain, and a coating film that contains lithium silicate and sodium silicate and is formed on the base film. The mass ratio of the mass of the active ingredient of the lithium silicate to the mass of the active ingredient of the sodium silicate is in a range of 0.07 to 2.5.