A breakaway threaded fastener is provided. The fastener has a stud, a pin, and a cap. The stud has a hollow cavity with a closed end, an open end, a wall, and an outer surface. The outer surface has an external thread. The pin is in the hollow cavity. The pin has a first end at the closed end of the stud and a second end extending above the open end of the stud. The cap has another hollow cavity with a closed end, an open end, and an internal thread. The cap is threadably engaged to the open end of the stud via the internal and external threads so that the second end of the pin abuts the closed end of the cap.

A breakaway threaded fastener is provided. The fastener has a stud, a pin, and a cap. The stud has a hollow cavity with a closed end, an open end, a wall, and an outer surface. The outer surface has an external thread. The pin is in the hollow cavity. The pin has a first end at the closed end of the stud and a second end extending above the open end of the stud. The cap has another hollow cavity with a closed end, an open end, and an internal thread. The cap is threadably engaged to the open end of the stud via the internal and external threads so that the second end of the pin abuts the closed end of the cap.

A bolt includes a head, and a shank connected to the head and having a screw portion and a leading end portion. The leading end portion of the shank includes a wall portion that defines a hole. The wall portion includes: a deformation portion configured to be plastically deformed by a torque from a fastening tool to be inserted in the hole; and a space forming portion configured to form a space between the space forming portion and the fastening tool. The blot is configured such that a maximum torque applied to the deformation portion in a process, in which a part of the deformation portion is plastically deformed by the torque from the fastening tool and is accommodated in the space and the fastening tool is placed in an idle rotation state, is configured to be set to be within a predetermined range.

A fastener assembly includes a stud, a threaded sleeve, and a compression spring. The stud includes a shaft with a first head at one end and a second head at an opposite end of the shaft, both heads with opposing bearing surfaces. The threaded sleeve is disposed about the shaft. The threaded sleeve includes external threads and a tubular interior with an inwardly projected shoulder. The compression spring is disposed about the shaft inside the threaded sleeve, with a first end bearing against a shoulder of the threaded sleeve and a second end bearing against a bearing surface of the second head. The spring urges the sleeve against the bearing surface of the first head. The assembly can maintain a preload between two components while allowing the components to be separated, and can also be used as a pressure limiter.

The present disclosure discloses a fastener assembly. The assembly comprises a stud having a head portion connectable to an actuator, and a shank extending from the head portion. At least a portion of the shank comprises threads, and an insulating material extends on the threads. A resistor module comprising one or more resistors is configured on the insulating material. One end of the one or more resistors is connectable to a power source, and other end of the one or more resistors is connectable to the power source through a nut engageable with the threads. A movement of the stud relative to the nut varies net resistance across the resistor module. The variation of net resistance across the resistor module may be used to determine position of the nut relative to the stud.

A coupler for separable physically coupling together a pair of objects includes two parts, on opposite sides of a boundary, that have different piezoelectric characteristics. When an electric field is applied to the coupler parts the piezoelectric forces induce a mechanical stress that separates the parts. The parts may be made of the same or a similar material, such as a suitable ceramic material, with the different piezoelectric characteristics produced by templating the parts with different domain orientations, from different seeds, for example using a three-dimensional manufacturing processes. The coupler may be used to allow shock-free (or reduced shock) separation of parts, such as separation of stages of vehicles such as flight vehicles.

A coupler for separable physically coupling together a pair of objects includes two parts, on opposite sides of a boundary, that have different piezoelectric characteristics. When an electric field is applied to the coupler parts the piezoelectric forces induce a mechanical stress that separates the parts. The parts may be made of the same or a similar material, such as a suitable ceramic material, with the different piezoelectric characteristics produced by templating the parts with different domain orientations, from different seeds, for example using a three-dimensional manufacturing processes. The coupler may be used to allow shock-free (or reduced shock) separation of parts, such as separation of stages of vehicles such as flight vehicles.

A coupling system for attaching a first part to a second part using a locator and expansion shear pin is disclosed. The first part has a first flange and may be a formed part, such as an intake manifold. The second part has a second flange and may be a component, such as a throttle body, for attachment to the first part. The component includes a fastener-passing bore having an inner diameter. The locator and expansion shear pin extends perpendicularly from the first flange. The pin includes an expansion wall extending beyond the surface of the flange. A fastener-receiving bore is formed concentrically in the pin relative to the wall. The wall is expandable from a first diameter to a second diameter. The first diameter is less than the inner diameter of the fastener-passing bore. The second diameter is at least equal to the inner diameter of the fastener-passing bore.

A coupling system for attaching a first part to a second part using a locator and expansion shear pin is disclosed. The first part has a first flange and may be a formed part, such as an intake manifold. The second part has a second flange and may be a component, such as a throttle body, for attachment to the first part. The component includes a fastener-passing bore having an inner diameter. The locator and expansion shear pin extends perpendicularly from the first flange. The pin includes an expansion wall extending beyond the surface of the flange. A fastener-receiving bore is formed concentrically in the pin relative to the wall. The wall is expandable from a first diameter to a second diameter. The first diameter is less than the inner diameter of the fastener-passing bore. The second diameter is at least equal to the inner diameter of the fastener-passing bore.

A thermally stabilized fastener system and method is disclosed. The disclosed system/method integrates a fastener (FAS) incorporating a faster retention head (FRH), fastener retention body (FRB), and fastener retention tip (FRT) to couple a mechanical member stack (MMS) in a thermally stabilized fashion using a fastener retention receiver (FRR). The MMS includes a temperature compensating member (TCM), a first retention member (FRM), and an optional second retention member (SRM). The TCM is constructed using a tailored thermal expansion coefficient (TTC) that permits the TCM to compensate for the thermal expansion characteristics of the FAS, FRM, and SRM such that the force applied by the FRH and FRR portions of the FAS to the MMS is tailored to a specific temperature force profile (TFP) over changes in MMS/FAS temperature. The TCM may be selected with a TTC to achieve a uniform TFP over changes in MMS/FAS temperature.