The invention relates to a device for viewing tension loss in a structure, by engagement with a threaded rod, being carried out, for example, by a bolt made up of a screw, a nut, and consisting of two non-deformable washers comprising an inner face, an outer face, an outer peripheral wall and an inner peripheral wall delimiting a central opening and a diametrically deformable viewing ring sandwiched between the two non-deformable washers, characterized in that the ring is crush-resistant and the thickness of at least one of the washers decreases from the center of the washer towards the peripheral end thereof, the smallest thickness thus being located towards the peripheral end of at least one washer.

A mounting system using a force indicator is disclosed. A screw is used to mount a bracket to a structure. While the screw is being threaded into the structure, the force indicator deforms to provides a visual indication when the screw is tight enough to secure the bracket to the structure without damaging the structure or mounting components. Additionally, a washer may be used with the mounting system. The force indicator can be cylinder shaped with a hole for the screw to pass through. The force indicator can extrude radially as it deforms in order to provide the visual indication.

A system for remotely retrieving sensed conditions at one or more building components. The building components are remote or numerous so that a wireless collection of the sensed conditions provides a significant benefit to a builder or building operator. A remote transceiver sends a wireless signal to a building component. The building component includes an onboard transceiver. At least some of the energy from the transmitted wireless signal is received by the onboard transceiver, sent to a storage device, and stored therein. The stored energy is used to operate a sensor for sensing an onboard condition. The onboard condition is then wirelessly transmitted by the onboard transceiver back to the remote transceiver to be displayed.

A pressure sensing device may include a body configured to distribute a load applied between first and second parts positioned one against the other, and a pressure sensor carried by the body. The pressure sensor may include a support body, and an IC die mounted with the support body and defining a cavity. The IC die may include pressure sensing circuitry responsive to bending associated with the cavity, and an IC interface coupled to the pressure sensing circuitry.

A reaction washer is optimized for lock-on, optional stiction ring and for a predetermined indentation depth of bidirectional serrations for secure reaction torque transfer during initial and full actuation of respective nut or bolt heads resting on it. An optional lock-on ring embedded around the reaction socket is ergonomically actuated to latch on and off underneath the reaction washer. Axial offset of the peak stress areas away from the actuation socket edges provides for reduced actuation socket diameter and consequently for the entire tool and system remaining substantially within radial assembly limits established for prior art actuation sockets alone. A coupling unit is attached to and tightened on a power torque wrench via a clamp tool utilizing the power wrench's own torque. A hand hold groove and a lock able snap release button offset from the coupling castle snap connection contribute to safe and ergonomic operation and system peak performance.

Deformable spacers and spacer assemblies absorb energy when flange bolts are subjected to compressive axial loads by plastically deforming, failing in shear, rupturing or in a combination of failure modes so the flange bolts and the flanges connected thereby are not damaged. One deformable spacer may have a hollow cylindrical body with a plurality of elongated slots there through. Another deformable spacer may have an annular stiffener extending inwardly from an inner surface of a hollow cylindrical body. A spacer assembly may include an inner cylindrical body, and outer cylindrical body, and an annular shoulder extending from one of the bodies and engaged by the other body shears when a shear failure load is applied to the flange bolt. Another spacer assembly may include an annular belt around a cylindrical body so that the belt will rupture before the cylindrical body plastically deforms.

An apparatus comprises a metal washer having an outer circumference, a plurality of cavities formed within the washer, wherein each cavity has an opening that is flush with the outer circumference, an indicator material comprising an inspection lacquer within at least one of the cavities, and a membrane along the outer circumference sealing the inspection lacquer within the cavity.

A monitoring system includes a fastener. A sensor is coupled to the fastener. A circuit board is electrically coupled to the sensor. An antenna electrically coupled to the circuit board.

A sensor (1) for measuring a tightening force applied on a screw-assembly member (2). The measurement sensor includes a ring and an electronic device comprising a longitudinal support strip having two opposite ends. The support strip is installed on a flat surface of the ring. The electronic device (26) includes a first circuit capable of generating a signal representative of a tightening force applied in a tightening direction on one of the two opposing faces; a second circuit capable of generating a signal representative of the distance of the applied force from the center of the ring in a first direction perpendicular to the tightening direction; and a third circuit capable of generating another signal representative of the distance of the applied force from the center of the ring in a second direction perpendicular to the tightening direction.

The invention relates to a solution for how to measure the strain in a washer mounted in a bolt assembly comprising a bolt, nut and washer. The invention concerns a strain measuring washer assembly comprising a plate shaped washer body, sound emitting means and sound detecting means, and a method for using such.