# US 10,480,566 B2 · Damage tolerant and fail-safe (DTFS) high strength preloaded pin assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,566 B2 - Document ID: US10480566B2 - Status: Granted - Kind: B2 - Application number: 15/073,155 - Filed: 2016-03-17 - Published: 2017-09-21 - Granted: 2019-11-19 - Earliest claimed: 2016-03-17 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Blake J. Bergeson; Joshua J. Bracken; Michael G. Poulson; Martin J. Clauss; Gunnar P. Bergeson - Web page: https://patentgrep.com/patent/US10480566B2 ## CPC - B64C 27/51: Damping of blade movements - B64C 27/48: Root attachment to rotor head - F16B 19/02: Bolts or sleeves for positioning of machine parts, e.g. notched taper pins, fitting pins, sleeves, eccentric positioning rings - F16B 33/00: Features common to bolt and nut - F16C 11/045: {with at least a pair of arms pivoting relatively to at least one other arm, all arms being mounted on one pin (crank-pins F16C11/02)} - F16B 37/14: Cap nuts; Nut caps or bolt caps - F16C 11/02: Trunnions; Crank-pins (fastening crank-pins to webs, crank-pins integral with cranks F16C3/06, F16C3/22) - Y10T 403/32918: fork and tongue - Y10T 403/75: having a joining piece extending through aligned openings in plural members - B64C: AEROPLANES; HELICOPTERS - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A fracture-resistant double shear joint including a clevis having a first end defining a first bore and a second end defining a second bore, and a reaction load member defining a third bore, wherein the first bore, the second bore, and the third bore are colinear. The fracture-resistant double shear joint can further include a first spacer positioned within the first bore, a second spacer positioned within the second bore, and a shear pin positioned within each of the first bore, the second bore, and the third bore. The shear pin may include an outer cylinder, an inner shear bolt threaded on both ends, and nuts at either end that engage the threads. The nuts may be tightened to place the outer cylinder in compression. The spacers in the first and second bore may include a low friction liner that interfaces with the outer cylinder of the shear pin. The ends of the spacers may be set back from the ends of the first and second bores (that are next to the third bore). ## Claims ### Claim 1 A fracture-resistant double shear joint, comprising: a clevis comprising a first end defining a first bore and a second end defining a second bore; a first bearing positioned within the first bore; a second bearing positioned within the second bore; a reaction load member defining a third bore, wherein the first bore, the second bore, and the third bore are colinear; a first spacer positioned within the first bore and a second spacer positioned within the second bore; a shear pin positioned within the first bore, the second bore, and the third bore, wherein the first spacer and the second spacer are configured to space the shear pin from the reaction load member defining the third bore; a shear bolt comprising a threaded first end and a threaded second end; an outer cylinder, wherein the shear bolt extends through an opening in the outer cylinder; a first nut threaded onto the threaded first end of the shear bolt; and a second nut threaded onto the threaded second end of the shear bolt, wherein an opposing force between the first nut and the second nut applies a compressive stress to the outer cylinder, wherein the opposing force between the first nut and the second nut applies a tensile force to the shear bolt during application of the compressive stress to the outer cylinder, wherein the first spacer is positioned between the first bearing and the outer cylinder and the second spacer is positioned between the second bearing and the outer cylinder. ### Claim 2 (depends on 1) The fracture-resistant double shear joint of claim 1, wherein the first spacer and the second spacer each include a substrate comprising at least one of a metal and a phenolic material, and further comprise a liner comprising polytetrafluoroethylene. ### Claim 3 (depends on 1) The fracture-resistant double shear joint of claim 1, wherein: the first spacer is a first liner that physically contacts the first end of the clevis and a first end of the shear pin; the second spacer is a second liner that physically contacts the second end of the clevis and a second end of the shear pin; and the shear pin is configured to transmit loads from the reaction load member to the first liner and to the second liner. ### Claim 4 (depends on 1) The fracture-resistant double shear joint of claim 1, further comprising: a first pin extender that physically contacts the first nut and a first end of the outer cylinder; and a second pin extender that physically contacts the second nut and a second end of the outer cylinder. ### Claim 5 (depends on 1) The fracture-resistant double shear joint of claim 1, further comprising: a first angled shoulder at a first end of the outer cylinder; and a second angled shoulder at a second end of the outer cylinder, wherein the first nut physically contacts the first angled shoulder and the second nut physically contacts the second angled shoulder. ### Claim 6 (depends on 1) The fracture-resistant double shear joint of claim 1, wherein the shear bolt has a length of from 4.0 inches to 10.0 inches and a diameter of from 0.5 inches to 2.5 inches. ### Claim 7 (depends on 1) The fracture-resistant double shear joint of claim 1, wherein the shear bolt, the outer cylinder, the first nut, and the second nut each comprise at least one of steel, a non-ferrous alloy, a nickel-cobalt-chromium-molybdenum alloy, and combinations thereof. ### Claim 8 (depends on 1) The fracture-resistant double shear joint of claim 1, further comprising: a cap having an opening therethrough, wherein the threaded first end of the shear bolt extends through the opening in the cap; and a fastener, wherein the fastener extends through a lateral hole in the threaded first end of the shear bolt. ### Claim 9 (depends on 8) The fracture-resistant double shear joint of claim 8, further comprising a sealant around a base of the cap. ### Claim 10 (depends on 1) The fracture-resistant double shear joint of claim 1, wherein: the first spacer is completely positioned between an upper extent and a lower extent of the first end of the clevis; and the second spacer is completely positioned between an upper extend and a lower extent of the second end of the clevis. ### Claim 11 (depends on 10) The fracture-resistant double shear joint of claim 10, configured such that a fracture of the shear pin results in the shear pin physically contacting, and being supported by, at least one of the first end and the second end of the clevis.