# US 10,500,685 B2 · Tensioner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,500,685 B2 - Document ID: US10500685B2 - Status: Granted - Kind: B2 - Application number: 15/116,988 - Filed: 2014-02-06 - Published: 2017-07-20 - Granted: 2019-12-10 - Earliest claimed: 2014-02-06 - Assignees: Tentec Limited - Applicants: Tentec Limited - Inventors: Michael Gethings; David Evans - Web page: https://patentgrep.com/patent/US10500685B2 ## CPC - B23P 19/067: {Bolt tensioners (for hand tools B25B29/02)} - B25B 29/02: Bolt tensioners - F16B 31/043: {Prestressed connections tensioned by means of liquid, grease, rubber, explosive charge, or the like (hydraulic bolt tensioners B25B29/02)} - G01L 1/12: by measuring variations in the magnetic properties of materials resulting from the application of stress - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - B25B: TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING - 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) - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract A tensioner, typically hydraulic, for threaded members, the tensioner comprising: a base (4) and a piston (6) defining a pressure space (13) therebetween, the base (4) and piston (6) being arranged to be urged apart along an axis (17) upon introduction of a fluid into the pressure space (13); and a thread-engaging member (7), comprising a body portion (8) of the form of a sleeve and having a threaded interior (30) for engagement with a threaded member (2) and a piston engaging portion (9) carrying a protrusion; in which the piston (6) bears against the protrusion such that the piston (6) exerts a force on the protrusion when urged apart from the base (4) by the introduction of fluid into the pressure space (13); the tensioner further comprising a displacement sensor arranged to determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part (12) carried on the base (4) and a second part (11) carried on the body portion (8); typically the displacement sensor is a magnetic encoder. ## Claims ### Claim 1 A tensioner for threaded members, the tensioner comprising: a base and a piston defining a pressure space therebetween, the base and piston being arranged to be urged apart along an axis upon introduction of a fluid into the pressure space; and a thread-engaging member, comprising a body portion having a threaded interior for engagement with a threaded member, a piston engaging portion carrying a protrusion, and a sleeve surrounding the body portion; in which the piston bears against the protrusion such that the piston exerts a force on the protrusion when urged apart from the base by the introduction of fluid into the pressure space; the tensioner further comprising a displacement sensor arranged for determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part carried on the base and a second part carried on the sleeve of the thread-engaging member; in which the sleeve is free to rotate around the body portion, but provided with a stop such that linear movement along the axis relative to the sleeve is restricted. ### Claim 2 (depends on 1) The tensioner of claim 1, in which the sleeve is fixed rotationally about the axis relative to the base. ### Claim 3 (depends on 2) The tensioner of claim 2, in which the sleeve is provided with at least one guide pin protruding from the sleeve and the base has at least one slot formed therein running along the axis, each guide pin being received in a corresponding slot. ### Claim 4 (depends on 1) The tensioner of claim 1, in which the displacement sensor is provided with an output for measured displacement, the output being provided with a wireless transmitter whereby the measured displacement can be transmitted to a remote location. ### Claim 5 (depends on 1) The tensioner of claim 1, being a hydraulic tensioner comprising a source of pressurised fluid in communication with the pressure space. ### Claim 6 A tensioner for threaded members, the tensioner comprising: a base and a piston defining a pressure space therebetween, the base and piston being arranged to be urged apart along an axis upon introduction of a fluid into the pressure space; and a thread-engaging member, comprising a body portion having a threaded interior for engagement with a threaded member, a piston engaging portion carrying a protrusion, and a sleeve surrounding the body portion; in which the piston bears against the protrusion such that the piston exerts a force on the protrusion when urged apart from the base by the introduction of fluid into the pressure space; the tensioner further comprising a displacement sensor arranged for determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part carried on the base and a second part carried on the sleeve of the thread-engaging member; in which the displacement sensor is a linear encoder, in which the second part comprises a scale that encodes a position and the first part is a transducer that reads the scale. ### Claim 7 (depends on 6) The tensioner of claim 6, in which the scale is a magnetic encoder, with the scale encoded magnetically and in which the transducer is a magnetic field sensor. ### Claim 8 (depends on 6) The tensioner of claim 6, in which the displacement sensor is provided with an output for measured displacement, the output being provided with a wireless transmitter whereby the measured displacement can be transmitted to a remote location. ### Claim 9 (depends on 6) The tensioner of claim 6, being a hydraulic tensioner comprising a source of pressurised fluid in communication with the pressure space. ### Claim 10 A combination, comprising: a tensioner; and a threaded member, in which the tensioner comprises: a base and a piston defining a pressure space therebetween, the base and piston being arranged to be urged apart along an axis upon introduction of a fluid into the pressure space; and a thread-engaging member, comprising a body portion having a threaded interior for engagement with a threaded member, a piston engaging portion carrying a protrusion, and a sleeve surrounding the body portion; in which the piston bears against the protrusion such that the piston exerts a force on the protrusion when urged apart from the base by the introduction of fluid into the pressure space; the tensioner further comprising a displacement sensor arranged for determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part carried on the base and a second part carried on the sleeve of the thread-engaging member; in which the sleeve is free to rotate around the body portion, but a stop is provided to prevent linear movement of the sleeve along the axis relative to the body portion; and in which the thread-engaging member is engaged with a thread of the threaded member. ### Claim 11 (depends on 10) The combination of claim 10, in which the second part of the displacement sensor is positioned axially along the sleeve of the thread-engaging member. ### Claim 12 (depends on 10) The combination of claim 10, in which the sleeve is fixed rotationally about the axis relative to the base. ### Claim 13 (depends on 12) The combination of claim 12, in which the sleeve is provided with at least one guide pin protruding from the sleeve and the base has at least one slot formed therein running along the axis, each guide pin being received in a corresponding slot. ### Claim 14 (depends on 10) The combination of claim 10, in which the displacement sensor is provided with an output for measured displacement, the output being provided with a wireless transmitter whereby the measured displacement can be transmitted to a remote location. ### Claim 15 (depends on 10) The combination of claim 10, wherein the tensioner is a hydraulic tensioner comprising a source of pressurised fluid in communication with the pressure space. ### Claim 16 A combination, comprising: a tensioner; and a threaded member, in which the tensioner comprises: a base and a piston defining a pressure space therebetween, the base and piston being arranged to be urged apart along an axis upon introduction of a fluid into the pressure space; and a thread-engaging member, comprising a body portion having a threaded interior for engagement with a threaded member, a piston engaging portion carrying a protrusion, and a sleeve surrounding the body portion; in which the piston bears against the protrusion such that the piston exerts a force on the protrusion when urged apart from the base by the introduction of fluid into the pressure space; the tensioner further comprising a displacement sensor arranged for determining the relative position of the body portion of the thread-engaging member and the base, the displacement sensor comprising a first part carried on the base and a second part carried on the sleeve of the thread-engaging member; in which the displacement sensor is a linear encoder, in which the second part comprises a scale that encodes a position and the first part is a transducer that reads the scale; and in which the thread-engaging member is engaged with a thread of the threaded member. ### Claim 17 (depends on 16) The combination of claim 16, in which the second part of the displacement sensor is positioned axially along the sleeve of the thread-engaging member. ### Claim 18 (depends on 16) The combination of claim 16, in which the scale is a magnetic encoder, with the scale encoded magnetically and in which the transducer is a magnetic field sensor. ### Claim 19 (depends on 16) The combination of claim 16, in which the displacement sensor is provided with an output for measured displacement, the output being provided with a wireless transmitter whereby the measured displacement can be transmitted to a remote location. ### Claim 20 (depends on 16) The combination of claim 16, wherein the tensioner is a hydraulic tensioner comprising a source of pressurised fluid in communication with the pressure space.