Abstract: A magnetomotive device has an embedded electromagnetic coil formed of multiple printed conductor segments on multiple lamina of a multilayer PCB. A shaft extends through an opening in the PCB, and a permanent magnet with axially opposed poles is secured to the shaft. Energizing the embedded electromagnet generates a magnetic field that attracts or repels the permanent magnet, driving the shaft to do useful work. A pair of embedded PCB coils may be employed, the shaft extending through both coils with the permanent magnet disposed therebetween, and the coils energized so that one repels the permanent magnet while the other attracts it, and the shaft may be driven reversibly to do useful work.

Abstract: Linear actuators comprised of a plurality of geometric links connected together in displacement multiplied fashion by a plurality of SMA wires. The links may have a trigon or chevron configuration. The trigon links may be combined with a hexagonal or rhomboidal shaft to create a defined stacking pattern of links about the shaft. The shaft extends from the medial portion of the stack. Ohmic heating circuits connect to non-moving ends of SMA wires. Various groupings of links in parallel displacement are described.

Abstract: Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin with a helical groove to receive an SMA wire. A number of turns may be placed in a small length of bobbin to amplify the rotational excursion. In another rotational actuator, a plurality of narrow, coaxial rings are provided, the rings being nested in close concentric fit or stacked in side-by-side fashion. Each ring is provided with a groove extending thereabout to receive an SMA wire and contraction of the wire causes each ring to rotate with respect to the adjacent ring. In an embodiment for linear actuation, the invention provides a bar-like component having SMA wires joined between bars.

Abstract: A method and apparatus for preventing the unintended activation of SMA devices by ambient temperatures that exceed the phase transition temperature of the SMA material itself. In one embodiment a passive actuator is coupled to an active actuator, each having identical arrangements of SMA wire, but connected in opposite directions to compensate for temperature drift that is not due to powered heating. A second embodiment consists of a passive SMA wire connected to a latch/release mechanism allowing the actuator itself to move rather than moving the load. In a third embodiment the passive wire is connected to a load coupling, so that the load itself is disconnected from the actuator when the passive wire reaches the phase transition temperature. The passive wire may be made of a lower-temperature wire than the active wires, so that the release action occurs long before the active wire begins to be moved by ambient temperature.

Abstract: Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin with a helical groove to receive an SMA wire. A number of turns may be placed in a small length of bobbin to amplify the rotational excursion. In another rotational actuator, a plurality of narrow, coaxial rings are provided, the rings being nested in close concentric fit or stacked in side-by-side fashion. Each ring is provided with a groove extending thereabout to receive an SMA wire and contraction of the wire causes each ring to rotate with respect to the adjacent ring. In an embodiment for linear actuation, the invention provides a bar-like component having SMA wires joined between bars.

Abstract: Linear actuators comprised of a plurality of geometric links connected together in displacement multiplied fashion by a plurality of SMA wires. The links may have a trigon or chevron configuration. The trigon links may be combined with a hexagonal or rhomboidal shaft to create a defined stacking pattern of links about the shaft. The shaft extends from the medial portion of the stack. Ohmic heating circuits connect to non-moving ends of SMA wires. Various groupings of links in parallel displacement are described.

Abstract: Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin with a helical groove to receive an SMA wire. A number of turns may be placed in a small length of bobbin to amplify the rotational excursion. In another rotational actuator, a plurality of narrow, coaxial rings are provided, the rings being nested in close concentric fit or stacked in side-by-side fashion. Each ring is provided with a groove extending thereabout to receive an SMA wire and contraction of the wire causes each ring to rotate with respect to the adjacent ring. In an embodiment for linear actuation, the invention provides a bar-like component having SMA wires joined between bars.

Abstract: A linear actuator includes a plurality of sub-modules disposed in adjacent array and adapted to translate reciprocally parallel to a common axis. A plurality of shape memory alloy wires extend generally linearly and parallel to the axis, and are each connected from one end of a sub-module to the opposed end of an adjacent sub-module. The SMA wires are connected in a circuit for ohmic heating that contracts the SMA wires between the sub-modules. The sub-modules are linked by the SMA wires in a serial mechanical connection that combines the constriction stroke displacement of the SMA wires in additive fashion to achieve a long output stroke. Moreover, the sub-modules are assembled in a small volume, resulting in an actuator of minimal size and maximum stroke displacement.

Abstract: A method and apparatus for preventing the unintended activation of SMA devices by ambient temperatures that exceed the phase transition temperature of the SMA material itself. In one embodiment a passive actuator is coupled to an active actuator, each having identical arrangements of SMA wire, but connected in opposite directions to compensate for temperature drift that is not due to powered heating. A second embodiment consists of a passive SMA wire connected to a latch/release mechanism allowing the actuator itself to move rather than moving the load. In a third embodiment the passive wire is connected to a load coupling, so that the load itself is disconnected from the actuator when the passive wire reaches the phase transition temperature. The passive wire may be made of a lower-temperature wire than the active wires, so that the release action occurs long before the active wire begins to be moved by ambient temperature.

Abstract: A vacuum feedthrough heatpipe assembly includes a heatpipe having an inner end coupled to a heat generating device within a vacuum chamber, and an outer end disposed externally of the vacuum chamber. A vacuum flange seals the heatpipe to an opening in the chamber wall. The invention also includes an articulated arm assembly, each arm being a sealed heat pipe, the arms joined by angularly adjustable elbow joints. The heatpipe may comprise an electrically insulating construction formed of quartz or ceramic tube.

Abstract: A linear actuator includes a plurality of sub-modules disposed in adjacent array and adapted to translate reciprocally parallel to a common axis. A plurality of shape memory alloy wires extend generally linearly and parallel to the axis, and are each connected from one end of a sub-module to the opposed end of an adjacent sub-module. The SMA wires are connected in a circuit for ohmic heating that contracts the SMA wires between the sub-modules. The sub-modules are linked by the SMA wires in a serial mechanical connection that combines the constriction stroke displacement of the SMA wires in additive fashion to achieve a long output stroke. Moreover, the sub-modules are assembled in a small volume, resulting in an actuator of minimal size and maximum stroke displacement.

Abstract: Actuators that employs a shape memory alloy component as the driving element include linear and rotational devices. An Intrinsic Return Means (IRM) may be imparted to the SMA actuator, thereby reducing the use of a spring return mechanism. The rotational actuator may include a cylindrical bobbin with a helical groove to receive an SMA wire. A number of turns may be placed in a small length of bobbin to amplify the rotational excursion. In another rotational actuator, a plurality of narrow, coaxial rings are provided, the rings being nested in close concentric fit or stacked in side-by-side fashion. Each ring is provided with a groove extending thereabout to receive an SMA wire and contraction of the wire causes each ring to rotate with respect to the adjacent ring. In an embodiment for linear actuation, the invention provides a bar-like component having SMA wires joined between bars.

Abstract: A vacuum feedthrough heatpipe assembly includes a heatpipe having an inner end coupled to a heat generating device within a vacuum chamber, and an outer end disposed externally of the vacuum chamber. A vacuum flange seals the heatpipe to an opening in the chamber wall. The invention also includes an articulated arm assembly, each arm being a sealed heat pipe, the arms joined by angularly adjustable elbow joints. The heatpipe may comprise an electrically insulating construction formed of quartz or ceramic tube.

Abstract: A linear actuator includes a plurality of sub-modules disposed in adjacent array and adapted to translate reciprocally parallel to a common axis. A plurality of shape memory alloy wires extend generally linearly and parallel to the axis, and are each connected from one end of a sub-module to the opposed end of an adjacent sub-module. The SMA wires are connected in a circuit for ohmic heating that contracts the SMA wires between the sub-modules. The sub-modules are linked by the SMA wires in a serial mechanical connection that combines the constriction stroke displacement of the SMA wires in additive fashion to achieve a long output stroke. Moreover, the sub-modules are assembled in a small volume, resulting in an actuator of minimal size and maximum stroke displacement.

Abstract: A device for limiting the intrusion of a shower curtain into a shower enclosure includes a clamp portion for releasably engaging the shower curtain rod, and an tail portion depending from the clamp portion for impinging on the shower curtain and urging it outwardly. The clamp includes an inverted U configuration adapted to extend about the curtain rod. The U-configuration includes one leg that is joined integrally to the tail portion, and the other leg is provided with a detent tip. A detent lever extends from the tail portion proximate to the detent tip, and includes an array of closely spaced detent teeth adapted to engage the detent tip. The detent lever is resiliently biased toward the detent tip, so that the tip remains engaged with the teeth unless otherwise disturbed. The two legs of the clamp may be squeezed together to engage the curtain rod frictionally to immobilize the device on the curtain rod, and the device will remain in this disposition until released.