# US 12,181,019 B2 · Systems and methods for assembling and repairing chains > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,181,019 B2 - Document ID: US12181019B2 - Status: Granted - Kind: B2 - Application number: 18/737,337 - Filed: 2024-06-07 - Published: 2024-10-03 - Granted: 2024-12-31 - Earliest claimed: 2021-12-09 - Assignees: Rexnord Industries, LLC - Applicants: Rexnord Industries, LLC - Inventors: David Keith Burkhardt; David Richard Woods; Joseph L Vento; Kyle Steven Jansson - Web page: https://patentgrep.com/patent/US12181019B2 ## CPC - F16G 13/06: with links connected by parallel driving-pins with or without rollers {so-called open links} - F16G: BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR ## Abstract A chain assembly system can include an inner chain link and an outer chain link. The inner chain link and the outer chain link can define a pair of bores. The chain assembly system can include a pin including a head end that defines a head, and a thread end opposite the head end having threads. The chain assembly system can include a nut configured to threadingly engage the threads of the thread end of the pin and an axial stop that is configured to block further advancement of the nut along the thread end of the pin towards the head end of the pin when the pin contacts the axial stop. ## Claims ### Claim 1 A chain assembly system comprising: an inner chain link; an outer chain link, the inner chain link and the outer chain link defining a pair of bores; a pin comprising a head end that defines a head, and a thread end opposite the head end having threads; a nut configured to threadingly engage the threads of the thread end of the pin; and an axial stop that is configured to block further advancement of the nut along the thread end of the pin towards the head end of the pin when the pin contacts the axial stop; wherein the thread end of the pin is configured to be inserted through the pair of bores that are aligned, and threadingly engaged with the nut that is configured to be externally positioned relative to the outer chain link; and wherein when the thread end of the pin is inserted and the nut is threadingly engaged with the thread end of the pin, the nut is configured to be tightened to create an interference fit between the pin and the outer chain link at the bore of the outer chain link, and further tightened until the pin contacts the axial stop to block translation of the pin thereby blocking translation of the nut. ### Claim 2 (depends on 1) The chain assembly system of claim 1, wherein the pin comprises a body that is coupled to the head end and the thread end, and wherein a first cross-section of the thread end is smaller than a second cross-section of the body to define a shoulder that is a radial step. ### Claim 3 (depends on 2) The chain assembly system of claim 2, further comprising a washer that defines the axial stop, the washer having a hole that is larger than the thread end of the pin on which the washer is receivable and small enough that the washer does not extend beyond the shoulder on the pin, such that, as the nut is advanced along the thread end and towards the head end to push the washer into the outer link and toward the shoulder of the pin, the washer contacts the shoulder of the pin to block further axial advancement of the nut thereby serving as the axial stop. ### Claim 4 (depends on 1) The chain assembly system of claim 1, wherein the nut comprises a bore defining an open end and an enclosed end, wherein the enclosed end includes a wall that is the axial stop, and wherein the pin contacts the wall to block further advancement of the nut along the pin. ### Claim 5 (depends on 4) The chain assembly system of claim 4, wherein the bore partially extends through the nut so that the wall fully encloses the nut. ### Claim 6 (depends on 5) The chain assembly system of claim 5, wherein the nut comprises a recess, wherein the bore is directed into one side of the nut, wherein the recess is directed into an opposing side of the nut, and wherein the recess is configured to receive a tool adapter to drive rotation of the nut. ### Claim 7 (depends on 1) The chain assembly system of claim 1, wherein the nut comprises: a first bore having a first cross-section; and a second bore coaxial to the first bore and adjacent thereto, the second bore having a second cross-section smaller than the first cross-section of the first bore, the second bore having threads, wherein an end surface of the nut proximal to the bore is the axial stop, wherein the thread end of the pin is configured to be inserted through the first bore, into the second bore, and threadingly engaged with the second bore, and wherein the surface of the nut at the second bore contacts the body of the pin to block further advancement of the pin, thereby blocking further advancement of the nut along the pin. ### Claim 8 (depends on 1) The chain assembly system of claim 1, wherein the nut is a single nut that is configured to be advanced along the thread end of the pin to create an interference fit between the pin and the outer chain link. ### Claim 9 (depends on 1) The chain assembly system of claim 1, wherein an exterior surface of the nut is configured to be engaged by a power tool to advance the nut to create the interference fit. ### Claim 10 (depends on 1) The chain assembly system of claim 1, wherein a portion of the pin is not configured to be broken off from the pin after the interference fit is created.