# US 11,442,238 B2 · Optical-fiber ribbon with spaced optical-fiber units > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,238 B2 - Document ID: US11442238B2 - Status: Granted - Kind: B2 - Application number: 17/130,568 - Filed: 2020-12-22 - Published: 2022-06-23 - Granted: 2022-09-13 - Earliest claimed: 2020-12-22 - Assignees: Prysmian S.p.A. - Applicants: Prysmian S.p.A. - Inventors: Ehsan Fallahmohammadi; Clint Nicholaus Anderson; Luca Giorgio De Rai - Web page: https://patentgrep.com/patent/US11442238B2 ## CPC - G02B 6/4403: {with ribbon structure (G02B6/4429, G02B6/4439, G02B6/4479 take precedence)} - G02B 6/448: {Ribbon cables} - G02B 6/2553: {Splicing machines, e.g. optical fibre fusion splicer} - G02B 6/441: {built up from sub-bundles (G02B6/4429, G02B6/4439, G02B6/4479 take precedence)} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract An optical-fiber ribbon includes optical fibers (e.g., reduced-diameter optical fibers) arranged in parallel within optical-fiber units, wherein at least one adjacent pair of optical-fiber units is separated by a longitudinal adhesive-free spacing for a portion of the optical-fiber ribbon's length. Typically, each adjacent pair of optical-fiber units is separated by an adhesive-free spacing for a respective portion of the optical-fiber assembly's longitudinal length. In an exemplary embodiment, longitudinal adhesive-free spacings effectively increase the width of an optical-fiber ribbon formed of reduced-diameter optical fibers so that the optical-fiber ribbon achieves a more conventional optical-fiber ribbon width, thereby facilitating mass-fusion splicing using standard splicing equipment. ## Claims ### Claim 1 An optical-fiber ribbon, comprising: (i) a plurality n of respectively adjacent optical fibers extending in a longitudinal direction and arranged in parallel to form an optical-fiber assembly having a width w extending crosswise to a longitudinal length of the optical-fiber assembly, wherein the n optical fibers have the same nominal diameter d and wherein the n optical fibers are uniformly distributed into a plurality U of respectively adjacent optical-fiber units whereby each of the U optical-fiber units has the same number un of optical fibers; and (ii) bonding material on the optical-fiber assembly adhesively bonding adjacent optical-fiber units and the corresponding adjacent optical fibers in the optical-fiber assembly, wherein each adjacent pair of optical-fiber units is separated by a longitudinal adhesive-free spacing for a respective portion of the optical-fiber assembly's longitudinal length, the respective longitudinal adhesive-free spacings having a mean gap width Savg, wherein: Savg≥(0.5·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 2 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the respective longitudinal adhesive-free spacings have a mean gap width Savg, wherein: Savg≥(0.7·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 3 (depends on 1) The optical-fiber ribbon according to claim 1, wherein adjacent optical fibers within each optical-fiber unit are respectively contiguous to one another. ### Claim 4 (depends on 1) The optical-fiber ribbon according to claim 1, wherein, for a portion of the optical-fiber assembly's longitudinal length, the bonding material comprises a continuous bead of bonding material. ### Claim 5 (depends on 1) The optical-fiber ribbon according to claim 1, wherein, for a portion of the optical-fiber assembly's longitudinal length, the bonding material comprises a plurality of successive elongated rectilinear beads arranged lengthwise along the optical-fiber assembly, wherein the beads are configured to form elongated bonds between adjacent optical fibers in the optical-fiber assembly. ### Claim 6 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the respective longitudinal adhesive-free spacings have a mean gap width Savg, wherein: Savg≥(0.75·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 7 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the respective longitudinal adhesive-free spacings have a mean gap width Savg, wherein: Savg≥(0.95·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 8 (depends on 1) The optical-fiber ribbon according to claim 1, wherein each of the n optical fibers has a nominal diameter d of between 180 microns and 200 microns. ### Claim 9 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the n optical fibers are uniformly distributed into two adjacent optical-fiber units whereby U=2. ### Claim 10 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the n optical fibers are uniformly distributed into three respectively adjacent optical-fiber units whereby U=3. ### Claim 11 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the n optical fibers are uniformly distributed into four respectively adjacent optical-fiber units whereby U=4. ### Claim 12 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the optical-fiber assembly includes between six and 36 optical fibers whereby 6≥n≥36. ### Claim 13 (depends on 1) The optical-fiber ribbon according to claim 1, wherein the optical-fiber assembly includes between 12 and 24 optical fibers whereby 12≥n≥24. ### Claim 14 An optical-fiber ribbon, comprising: (i) a plurality n of respectively adjacent optical fibers extending in a longitudinal direction and arranged in parallel to form an optical-fiber assembly having a width w extending crosswise to a longitudinal length of the optical-fiber assembly, wherein the n optical fibers have the same nominal diameter d of between 180 microns and 200 microns, wherein the n optical fibers are uniformly distributed into a plurality U of respectively adjacent optical-fiber units whereby each of the U optical-fiber units has the same number un of optical fibers, and wherein adjacent optical fibers within each optical-fiber unit are respectively substantially contiguous to one another; and (ii) bonding material on the optical-fiber assembly adhesively bonding adjacent optical-fiber units and the corresponding adjacent optical fibers in the optical-fiber assembly, wherein each adjacent pair of optical-fiber units is separated by a longitudinal adhesive-free spacing for a respective portion of the optical-fiber assembly's longitudinal length, the respective longitudinal adhesive-free spacings having a mean gap width Savg, wherein: Savg≥(0.5·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 15 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the respective longitudinal adhesive-free spacings have a mean gap width Savg, wherein: Savg≥(0.7·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 16 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the respective longitudinal adhesive-free spacings have a mean gap width Savg, wherein: Savg≥(0.95·n·(d250−d))÷(U−1), where d250 is 250 microns, the nominal width of a conventional optical fiber. ### Claim 17 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the n optical fibers are uniformly distributed into two adjacent optical-fiber units whereby U=2. ### Claim 18 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the n optical fibers are uniformly distributed into three respectively adjacent optical-fiber units whereby U=3. ### Claim 19 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the n optical fibers are uniformly distributed into four respectively adjacent optical-fiber units whereby U=4. ### Claim 20 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the optical-fiber assembly includes between six and 36 optical fibers whereby 6≥n≥36. ### Claim 21 (depends on 14) The optical-fiber ribbon according to claim 14, wherein the optical-fiber assembly includes between 12 and 24 optical fibers whereby 12≥n≥24.