A method of attenuating annular pressure buildup within a wellbore. The method includes accessing a wellbore, with the wellbore having an annulus disposed between first and second strings of casing. The method also includes placing a column of cement around the second string of casing generally below the first string of casing. The method further includes pumping a fluid mixture into the annulus, forming a fluid column. The fluid mixture comprises a carrier fluid, and a plurality of compressible particles dispersed in the carrier fluid. Each of the compressible particles is fabricated to partially collapse in response to thermal expansion of the fluid mixture. The method also includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore. The method additionally includes at least partially sealing the annular region along at least one depth above the column of cement to inhibit vertical migration of the compressible particles.

A head unit device for controlling motion of an object includes a chamber filled with a shear thickening fluid (STF) and a piston. The piston is housed within the chamber and exerts pressure against the STF from a force applied to the piston from the object. The STF is configured to have a decreasing viscosity in response to a first range of shear rates and an increasing viscosity in response to a second range of shear rates. The piston includes at least one piston bypass between opposite sides of the piston that controls flow of the STF between the opposite sides of the piston to selectively react with a shear threshold effect of the first range of shear rates or the second range of shear rates.

A shock absorber includes a first end configured to be mechanically fastened to a first component, a second end configured to be mechanically fastened to a second component, a main body, a main shaft, and a primary piston. The primary piston configured to move within the main body and further configured to provide a first damping force by movement of a fluid through the primary piston while the main shaft moves a first distance. The shock absorber also includes a deformable solid material arranged in the main body. The primary piston configured to further move within the main body and further configured to provide a second damping force by deforming the deformable solid material after the main shaft moves the first distance.

Technologies are described for a cap sensor unit for an energy absorber. The cap sensor unit may comprise a housing. The housing may be configured to be attachable to, and removable from, an end of a piston of the energy absorber. Walls of the housing may define a pocket for a sensor within the housing. The caps sensor unit may comprise the sensor. The sensor may be within the housing. The sensor may be a wireless position switch. The sensor may include a wireless transmitter. The sensor may be configured to send a signal to a receiver when a force impacts the cap sensor unit. The sensor may be in a load path of the force.

A shock absorber includes a first end configured to be mechanically fastened to a first component, a second end configured to be mechanically fastened to a second component, a main body, a main shaft, and a primary piston. The primary piston configured to move within the main body and further configured to provide a first damping force by movement of a fluid through the primary piston while the main shaft moves a first distance. The shock absorber also includes a deformable solid material arranged in the main body. The primary piston configured to further move within the main body and further configured to provide a second damping force by deforming the deformable solid material after the main shaft moves the first distance.

A double-shockproof spring mechanism, a cam ejection mechanism and a single-side guide rail ejection bin, which relates to the technical field of pet snack device components. The double-shockproof spring comprises a guide rod and a first elastic element, a slider and a second elastic element which are sleeved on the guide rod in sequence, wherein the slider is slidable along the guide rod under the action of the first elastic element and the second elastic element; the cam ejection mechanism comprises a power device, an ejection cam, a pushing plate and a double-shockproof spring mechanism; and the single-side guide rail ejection bin comprises an ejection bin body and a cam ejection mechanism mounted on the ejection bin body; the single-side guide rail ejection bin of the present invention not only can project pet snacks, but also project periodically and continuously.

A double-shockproof spring mechanism, a cam ejection mechanism and a single-side guide rail ejection bin, which relates to the technical field of pet snack device components. The double-shockproof spring comprises a guide rod and a first elastic element, a slider and a second elastic element which are sleeved on the guide rod in sequence, wherein the slider is slidable along the guide rod under the action of the first elastic element and the second elastic element; the cam ejection mechanism comprises a power device, an ejection cam, a pushing plate and a double-shockproof spring mechanism; and the single-side guide rail ejection bin comprises an ejection bin body and a cam ejection mechanism mounted on the ejection bin body; the single-side guide rail ejection bin of the present invention not only can project pet snacks, but also project periodically and continuously.

This invention discloses a semi-active rigid-flexible coupling exoskeleton based on a single-loop bidirectional damping regulator and relates to a power assisting mechanism in the field of robots, the exoskeleton including a waist assembly, a leg assembly, and a hydraulic damping regulator; the hydraulic damping regulator includes a cylinder body, a titanium alloy sleeve, a cylinder head, a piston, an extension assisting spring, an oil injection port plug, a staggered channel-type valve body, a valve body sealing seat, a valve body-end bevel gear, an angle sensor, a motor fixing seat, a DC servo motor, a coupler, and a motor-end bevel gear. According to the invention, two modes of power assistance or damping regulation, i.e., a heavy-object-carrying mode and a walking-with-load mode, can be enabled; the heavy-object-carrying mode supports carrying from a higher to a lower position and the other way around, characterized by good applicability; moreover, the knee joint can be assisted when naturally bending in a stooping state; a semi-active torque adjusting system is formed with a hydraulic damper and a spring, with the magnitude of assistance and damping force adjustable; also, this invention features a light weight and good man-machine coupling.

A method of attenuating annular pressure buildup within a wellbore. The method includes accessing a wellbore, with the wellbore having an annulus disposed between first and second strings of casing. The method also includes placing a column of cement around the second string of casing generally below the first string of casing. The method further includes pumping a fluid mixture into the annulus, forming a fluid column. The fluid mixture comprises a carrier fluid, and a plurality of compressible particles dispersed in the carrier fluid. Each of the compressible particles is fabricated to partially collapse in response to thermal expansion of the fluid mixture. The method also includes placing a wellhead over the wellbore, thereby forming a trapped annulus in the wellbore. The method additionally includes at least partially sealing the annular region along at least one depth above the column of cement to inhibit vertical migration of the compressible particles.

A suspension unit for a front fork of a vehicle includes an annular tube. The first tube defines a compression chamber and a damping chamber. A damper includes a first valve allowing gas to variably flow from the compression chamber to the damping chamber and a second valve allowing gas to flow from the damping chamber to the compression chamber. An external adjuster allows a rider to adjust the first valve to improve ride conditions.