Abstract: An actuator assembly includes a compliant actuator shaft having an axis (A) and a first end and a second end, a drive assembly provided at the first end of the compliant actuator shaft to cause rotation of the compliant actuator shaft about the axis and an overtravel stop mechanism. The overtravel stop mechanism includes: a screw shaft mounted to and arranged to rotate with the second end of the compliant actuator shaft, the screw shaft having an outer thread extending in the axial direction; a nut threadedly mounted to the outer thread of the screw shaft that moves axially relative to the screw shaft as the screw shaft rotates; a first stop fixed to and radially extending from the screw shaft to define the axial limit of movement of the nut relative to the screw shaft, in a first axial direction.

Abstract: An actuator includes: a cylinder, formed of carbon fiber reinforced polymer (CFRP), that extends along an actuator axis between a cylinder first end and a cylinder second end, and defines a cylinder inner diameter surface; a screw shaft that extends along the actuator axis between a screw shaft first end and a screw shaft second end, that is at least partially within the cylinder, and that is operationally connected, intermediate of the screw shaft first and second ends, to the cylinder second end; a screw shaft head affixed to the screw shaft first end, that in operation rotates relative to the cylinder, and that defines a screw shaft head outer diameter surface that faces the cylinder inner diameter surface with a slip fit therebetween; and a bearing ring affixed to the screw shaft head outer diameter surface, that is formed of polyether ether ketone (PEEK).

Abstract: A system for stopping rotation of a first gear and a second gear on a shaft, The first gear and second gear are concentric and rotatable about said shaft. The first gear and the second gear are driven by the same input system and the first gear and the second gear are configured to rotate at differential speeds and independently to each other. The first gear comprises a first end stop and the second gear comprises a second end stop and the first end stop and the second end stop are configured to engage each other when the first gear and the second gear have each rotated a predetermined number of turns. Engagement of the first end stop with the second end stop is configured to prevent rotation of the first gear and the second gear and cause a stall in the system.

Abstract: An actuator assembly includes a compliant actuator shaft having an axis (A) and a first end and a second end, a drive assembly provided at the first end of the compliant actuator shaft to cause rotation of the compliant actuator shaft about the axis and an overtravel stop mechanism. The overtravel stop mechanism includes: a screw shaft mounted to and arranged to rotate with the second end of the compliant actuator shaft, the screw shaft having an outer thread extending in the axial direction; a nut threadedly mounted to the outer thread of the screw shaft that moves axially relative to the screw shaft as the screw shaft rotates; a first stop fixed to and radially extending from the screw shaft to define the axial limit of movement of the nut relative to the screw shaft, in a first axial direction.

Abstract: A system for stopping rotation of a first gear and a second gear on a shaft, The first gear and second gear are concentric and rotatable about said shaft. The first gear and the second gear are driven by the same input system and the first gear and the second gear are configured to rotate at differential speeds and independently to each other. The first gear comprises a first end stop and the second gear comprises a second end stop and the first end stop and the second end stop are configured to engage each other when the first gear and the second gear have each rotated a predetermined number of turns. Engagement of the first end stop with the second end stop is configured to prevent rotation of the first gear and the second gear and cause a stall in the system.

Abstract: An actuator includes: a cylinder, formed of carbon fiber reinforced polymer (CFRP), that extends along an actuator axis between a cylinder first end and a cylinder second end, and defines a cylinder inner diameter surface; a screw shaft that extends along the actuator axis between a screw shaft first end and a screw shaft second end, that is at least partially within the cylinder, and that is operationally connected, intermediate of the screw shaft first and second ends, to the cylinder second end; a screw shaft head affixed to the screw shaft first end, that in operation rotates relative to the cylinder, and that defines a screw shaft head outer diameter surface that faces the cylinder inner diameter surface with a slip fit therebetween; and a bearing ring affixed to the screw shaft head outer diameter surface, that is formed of polyether ether ketone (PEEK).

Abstract: A system for spectral induced polarization measurement of a formation is provided. The system provides an intelligent module to be utilized in performing spectral induced polarization (SIP) measurements for geophysical studies or otherwise. The system includes a instrument that includes a housing configured to be inserted into a surface opening. The housing houses a signal generator that generates an excitation signal. A drive electrode directs the excitation signal into the material adjacent the housing. A plurality of electrodes sense the voltage and/or current in the material adjacent the housing and a processor processes the sensed voltage and/or current to measure a property of the material. The system also provides a configuration in which a plurality of instruments configured for spectral induced polarization measurements are interconnected to provide communication, synchronization, a common reference signal or power.

Abstract: A system for spectral induced polarization measurement of a formation is provided. The system provides an intelligent module to be utilized in performing spectral induced polarization (SIP) measurements for geophysical studies or otherwise. The system includes a instrument that includes a housing configured to be inserted into a surface opening. The housing houses a signal generator that generates an excitation signal. A drive electrode directs the excitation signal into the material adjacent the housing. A plurality of electrodes sense the voltage and/or current in the material adjacent the housing and a processor processes the sensed voltage and/or current to measure a property of the material. The system also provides a configuration in which a plurality of instruments configured for spectral induced polarization measurements are interconnected to provide communication, synchronization, a common reference signal or power.