There is set forth herein an articulated arm, the articulated arm comprising a first rigid link assembly and a second rigid link assembly. The articulated arm can be configured so that the second rigid link assembly rotates in relation to the first link assembly about a rotary axis. The articulated arm can include an actuator for causing rotary movement of the second rigid, link assembly in relation to the first rigid link assembly about the rotary axis. The actuator can include a first fluid chamber, and a second fluid chamber. The articulated arm can include a fluid supply assembly for moving fluid into and out of the first fluid chamber and the second fluid chamber.

Hydraulic rotary actuator disposes entry and exit lines of the hydraulic fluid within the hydraulic rotary actuator and comprises a floating member with a hollow portion, a rotating member configured to be inserted into the hollow portion, a working fluid supplied to said hollow portion, a servo control valve connected to said floating member configured to control the flow rate, an entry line connected to said servo control valve and further connecting said servo control valve to said floating member, said entry line forming a through-hole that penetrates through said floating member and forming a supply passage for said working fluid, an exit line connecting said hollow portion to said servo control valve and further thereon to outside of floating member, said exit line forming a through-hole that penetrates through said floating member and forming a discharge passage for said working fluid.

There is set forth herein an articulated arm, the articulated arm comprising a first rigid link assembly and a second rigid link assembly. The articulated arm can be configured so that the second rigid link assembly rotates in relation to the first link assembly about a rotary axis. The articulated arm can include an actuator for causing rotary movement of the second rigid link assembly in relation to the first rigid link assembly about the rotary axis. The actuator can include a first fluid chamber, and a second fluid chamber. The articulated arm can include a fluid supply assembly for moving fluid into and out of the first fluid chamber and the second fluid chamber.

An example device may include a rounded outer incline ramp and a rounded inner incline ramp surrounding a central axis. The rounded inner incline ramp and the rounded outer incline ramp may be inversely aligned relative to the central axis. The device may also include a piston carrier oriented in a direction parallel to the central axis. The piston carrier may include a first piston including a first roller positioned on the two ramps at a first point, where the first piston is configured to act on the two ramps in a direction parallel to the central axis. The piston carrier may also include a second piston including a second roller positioned on the two ramps at a second point opposite the first point, where the second piston is configured to act on the two ramps in a direction parallel to the central axis.

A head for a swing arm assembly is provided for a spot welding machine. The head can accommodate a tip dresser or a tip exchanger.

A swing arm assembly is provided for a spot welding machine. The swing arm assembly can accommodate a tip dresser or a tip exchanger and can include a shifter that can translate the tip dresser from a first position to a second position along a lateral axis.

An arm structure includes a shoulder joint, an elbow joint, a wrist joint, a first connection structure connecting the shoulder joint with the elbow joint and that relatively moves while maintaining an orientation of the elbow joint relative to the shoulder joint, a second connection structure connecting the elbow joint with the wrist joint and that relatively moves while maintaining an orientation of the wrist joint relative to the elbow joint, a third connection structure connecting the shoulder joint with the second connection structure and that relatively moves while maintaining an orientation of the wrist joint relative to the shoulder joint, a first actuator that rotates a first rotating shaft included in the first connection structure, and a second actuator that rotates a second rotating shaft included in the third connection structure. The first and second rotating shafts are supported by the shoulder joint.

Devices and systems for producing rotational actuation are described. More specifically, hydraulic and pneumatic actuators that can produce and control rotational or joint-like motion are described. An actuator may be configured to allow parallel coupling of multiple actuators, and thus increase the range of rotation of the actuators when considered collectively.

An example device may include a rounded outer incline ramp and a rounded inner incline ramp surrounding a central axis. The rounded inner incline ramp and the rounded outer incline ramp may be inversely aligned relative to the central axis. The device may also include a piston carrier oriented in a direction parallel to the central axis. The piston carrier may include a first piston including a first roller positioned on the two ramps at a first point, where the first piston is configured to act on the two ramps in a direction parallel to the central axis. The piston carrier may also include a second piston including a second roller positioned on the two ramps at a second point opposite the first point, where the second piston is configured to act on the two ramps in a direction parallel to the central axis.

There is provided a mechanical avatar assembly for use in a confined space in a structure. The mechanical avatar assembly includes a rail assembly for attachment to an access opening to the confined space. The rail assembly includes two or more rail segments coupled together to form an elongated base having a rail and a gear rack extending along a length of the elongated base. The rail assembly further includes a carriage portion coupled to the rail, and movable relative to the rail, and a drive assembly coupled to the carriage portion and to the gear rack, to move the carriage portion along the rail. The mechanical avatar assembly further includes an articulating avatar arm coupled to, and movable via, the carriage portion. The mechanical avatar assembly further includes an image capturing device.