A method for forming a laser-marked chain assembly. The method includes: coupling a plurality of chain links to one another for form a length of chain having a first and a second end; marking an outer plate of at least one of the plurality of chain links with a laser; and coupling the first and second ends to one another to form the laser-marked chain assembly.

FIELD

The present disclosure relates to a laser-marked chain for use in a chain drive system.

BACKGROUND

Chain drives are widely used in systems to convey rotary motion between components whose rotational axes are non-coincident. Once common use for a chain drive involves the transmission of rotary power from the crankshaft of an internal combustion engine to drive one or more camshafts. These chain drives have a chain assembly that can be configured as roller chain or a leaf chain. With such chain drives, it is common for one or more of the chain links to be provided with markings to identify a) the part number of the chain assembly, b) a country of origin for the chain assembly, c) the manufacturer of the chain assembly, d) the customer or original equipment manufacturer (OEM) of the chain assembly, and/or e) one or more timing marks on the chain assembly.

Some of the above-described information has been incorporated into a chain assembly by stamping a mark onto the outer plate of at least one of the chain links. Marking in this manner requires that the outer plate be marked prior to the assembly of the chain assembly and as such, the manufacture of the chain assembly is complicated by the existence of various outer plates that are each employed in a specific chain assembly but which may be inadvertently interchanged with one another. Moreover, the use of outer plates that are vary from one another only in the marking or coloration increases the cost of the chain assembly due to the need to procure and store these outer plates and due to the need to change-over from one outer plate to another when changing over from the manufacture of one chain assembly to another chain assembly. Additionally, the stamping of the outer plate can adversely affect the flatness of the inboard side of the outer plate and create high spots corresponding to the shape of the marking (on the out-board side of) the outer plate. In extreme situations, the high spots can lead to increased wear on the outer plate.

Other means for marking a chain assembly include the use of color-coded outer plates in which the color-coding of the outer plate is done prior to or after assembly of the chain assembly. While such other marking means can eliminate the issues with the flatness of the inboard side of the outer plate, they can be associated with various other issues, including chemical compatibility, hydrogen embrittlement, and increased cost due to the need for additional process steps such as heat-curing.

In view of the above remarks, there remains a need in the art for a chain assembly having a link with an outer plate that is permanently marked in a cost effective manner.

SUMMARY

In one form, the present disclosure provides a method for forming a laser-marked chain assembly. The method includes: coupling a plurality of chain links to one another for form a length of chain having a first and a second end; marking an outer plate of at least one of the plurality of chain links with a laser; and coupling the first and second ends to one another to form the laser-marked chain assembly.

In one preferred form, marking the outer plate of at least one of the plurality of chain links with the laser is performed prior to coupling the first and second ends to one another.

In one preferred form, marking the outer plate of at least one of the plurality of chain links comprises forming a timing mark.

In one preferred form, marking the outer plate of at least one of the plurality of chain links comprises forming a code that includes a part number of the laser-marked chain assembly. The code can optionally comprise a bar code or a data matrix. In situations where the code comprises a data matrix, the data matrix can optionally include a revision level of the laser-marked chain assembly, a date of manufacture of the laser-marked chain assembly, an identify of a machine on which the laser-marked chain assembly was assembled, and/or an identity of a facility where the laser-marked chain assembly was assembled.

In another preferred form, the present disclosure provides a laser-marked chain assembly that comprises a plurality of links, each of the links having a plurality of plates, the plates of adjacent links being coupled to one another via a pin, wherein an outer plate of at least one of the links is laser etched with a mark. The mark could comprise a timing mark, an alpha-numeric character, and/or a code, such as a bar code or a data matrix.

DETAILED DESCRIPTION

With reference toFIG. 1, several chain assemblies constructed in accordance with the teachings of the present disclosure are illustrated, including chain assembly10. With reference toFIG. 2, chain assembly10is a type of leaf chain and includes a plurality of link plates16, a plurality of outer plates18and a plurality of pins20. It will be appreciated, however, that the teachings of the present disclosure have application to other types of chain assemblies, including those chain assemblies that are configured as a type of roller chain.

In the example provided, the link plates16are segregated into sets, with the ends of each adjacent set of link plates16being interlaced. The outer plates18can be disposed on laterally outer sides of the sets of link plates16. Each of the pins20can be received through corresponding pin apertures formed in the link plates16and the outer plates18to pivotally couple the ends of each of the link plates16to a corresponding end of an adjacent one of the outer plates18.

InFIGS. 3 and 4, portions of the chain assembly10are illustrated in more detail. InFIG. 3, one of the outer plates18is permanently marked via a laser with a timing mark30, while another one of the outer plates18is illustrated inFIG. 4to be permanently marked via a laser with a character32, which is the number “3” in the example provided. The character32can be a trademark of the manufacturer of the chain assembly, or can be part of a name or number that is disposed over several adjacent outer plates18. Alternatively, the character32can be a code, which can be representative of a manufacturing date, a customer or a manufacturer of the chain assembly10. With reference toFIGS. 5 and 6, the code of the character32could take the form a data matrix or bar code (not shown). A data matrix permits a very large amount of data to be coded directly onto the outer plate18. The information in the data matrix could in turn be encoded so that even more data could be associated with the chain assembly10(FIG. 2). Moreover, several of the outer plates18could be marked, each with a unique data matrix, so that still more data can be associated with the chain assembly10(FIG. 2). Examples of such data include a multi-character code that is associated with a customer of the chain assembly10(FIG. 2), a manufacturing code, which could identify the part number and revision level of the chain assembly10(FIG. 2), and a production code that could include the identity of the facility that manufactured the chain assembly10(FIG. 2), the date of manufacture of the chain assembly10(FIG. 2), the identity of the machine on which the chain10(FIG. 2) was assembled, and the time or shift at which the chain assembly10(FIG. 2) was assembled.

Returning toFIG. 2, the marking of the outer plate(s)18may be performed as a separate operation during the assembly of the chain assembly10, or could be performed by a laser that is tasked with performing another operation, such as welding the pins20to the outer plates18. Marking of the outer plate(s)18during assembly of the chain assembly10is highly desirable because it eliminates complexity (e.g., unique part numbers, the need to assemble pre-marked outer plates into the assembly at one or more desired locations) and can reduce the frequency of inspection of the finished chain assembly10.

With reference toFIGS. 7 and 8, a portion of an exemplary machine50for fabricating the chain assembly10is shown. The machine50includes a laser52and a holder54for securing at least a portion of the chain assembly10when the laser52is operated to form a desired mark on an outer plate18of the chain assembly10. The laser can be any appropriate laser, such as a model Arex 20W fiber laser manufactured by Datalogic S.p.A.