A single-use pressure-controlled actuator for downhole well tools or mechanisms is provided. The actuator is configured for control of activation/deactivation by agency of wellbore fluid pressure (e.g., pressure levels of drilling fluid or drilling mud in the wellbore). The actuator is further configured for hydraulic actuation by agency of the wellbore fluid. The actuator comprises a plunger displaceably mounted on a sealed cylinder body, with a non-reclosable frangible device closing off wellbore fluid access to an interior of the cylinder body. The frangible device is configured for automatic in response to exposure of wellbore fluid pressures exceeding a predetermined activation threshold. Failure of the frangible device causes exposure of the plunger to the wellbore fluid, resulting in actuated movement of the plunger by hydraulic action of the wellbore fluid.

A single-use pressure-controlled actuator for downhole well tools or mechanisms is provided. The actuator is configured for control of activation/deactivation by agency of wellbore fluid pressure (e.g., pressure levels of drilling fluid or drilling mud in the wellbore). The actuator is further configured for hydraulic actuation by agency of the wellbore fluid. The actuator comprises a plunger displaceably mounted on a sealed cylinder body, with a non-reclosable frangible device closing off wellbore fluid access to an interior of the cylinder body. The frangible device is configured for automatic in response to exposure of wellbore fluid pressures exceeding a predetermined activation threshold. Failure of the frangible device causes exposure of the plunger to the wellbore fluid, resulting in actuated movement of the plunger by hydraulic action of the wellbore fluid.

An actuator includes a guide that extends in one direction and a slider that is movable in an axial direction with respect to the guide. Either the guide or the slider has a recessed cross-section, and the slider is guided by the guide while the other of the guide and the slider is restrained by three surfaces constituting the recessed cross-section.

An actuator includes a guide that extends in one direction and a slider that is movable in an axial direction with respect to the guide. Either the guide or the slider has a recessed cross-section, and the slider is guided by the guide while the other of the guide and the slider is restrained by three surfaces constituting the recessed cross-section.

An actuator includes a housing defining an inlet port, a piston and a return spring disposed within the housing, and an elastically deformable element. The return spring is configured to apply a biasing force to the piston to move the piston to a spring return position. A first fluid pressure applied to the inlet port moves the piston against the biasing force of the return spring to a first actuated position in which the piston indirectly engages a stop portion of the actuator housing. A second fluid pressure, greater than the first fluid pressure, applied to the inlet port moves the piston against the elastically deformable element to compress the elastically deformable element to move the piston to a second actuated position beyond the first actuated position.

An inflatable structure includes a top end cap, a bottom end cap, a bladder, a nozzle, a loop, and a first tether. The bladder is attached to the top and bottom end caps and is configured to hold pressurized fluid therebetween. The nozzle is configured to allow fluid to enter and exit the bladder. The loop is attached to one of the top and bottom end caps. A tether is disposed within the bladder, coupled to the other one of the top and bottom end caps, and extends through the at least one loop. The top end cap assumes a first position when the bladder is inflated. When the top end cap is adjusted from the first position to a second position, the first tether is configured to maintain the top end cap in the second position.

An inflatable structure includes a top end cap, a bottom end cap, a bladder, a nozzle, a loop, and a first tether. The bladder is attached to the top and bottom end caps and is configured to hold pressurized fluid therebetween. The nozzle is configured to allow fluid to enter and exit the bladder. The loop is attached to one of the top and bottom end caps. A tether is disposed within the bladder, coupled to the other one of the top and bottom end caps, and extends through the at least one loop. The top end cap assumes a first position when the bladder is inflated. When the top end cap is adjusted from the first position to a second position, the first tether is configured to maintain the top end cap in the second position.

A Scotch yoke actuator includes a housing formed with four piston bores spaced equally 90° from each other, a shaft with four yokes, each of the yokes having a slot, and four pistons including two pairs of 180° opposing pistons, one pair of the opposing pistons being orthogonal to the other pair of the opposing pistons. Each of the pistons is arranged for linear motion in one of the piston bores. Each of the pistons includes a piston rod which includes a piston pin which is slidable in the slot. Linear motion of the pistons in the piston bores causes rotation of the shaft.

A Scotch yoke actuator includes a housing formed with four piston bores spaced equally 90° from each other, a shaft with four yokes, each of the yokes having a slot, and four pistons including two pairs of 180° opposing pistons, one pair of the opposing pistons being orthogonal to the other pair of the opposing pistons. Each of the pistons is arranged for linear motion in one of the piston bores. Each of the pistons includes a piston rod which includes a piston pin which is slidable in the slot. Linear motion of the pistons in the piston bores causes rotation of the shaft.

An actuator includes a housing defining an inlet port, a piston and a return spring disposed within the housing, and an elastically deformable element. The return spring is configured to apply a biasing force to the piston to move the piston to a spring return position. A first fluid pressure applied to the inlet port moves the piston against the biasing force of the return spring to a first actuated position in which the piston indirectly engages a stop portion of the actuator housing. A second fluid pressure, greater than the first fluid pressure, applied to the inlet port moves the piston against the elastically deformable element to compress the elastically deformable element to move the piston to a second actuated position beyond the first actuated position.