Abstract: All-elastomer fluid-pressure-actuatable twistors have an elongated tubular wall of resilient elastomeric material extending between first and second mounting ends spaced from each other along a twist axis extending longitudinally within the twistor. The tubular wall encircles its twist axis and surrounds an elongated interior chamber. Interior reinforcing webs of resilient elastomeric material are joined to the wall. These web-partitions extend longitudinally within the chamber, separating the chamber into longitudinally extending compartments. By applying torque or other preform means in a first sense to the first mounting end relative to the second mounting end, the tubular wall and interior webs become twisted in the same sense around the twist axis into a generally helically-twisted configuration.

Abstract: A six-legged, insect-like, self-propelled walking robot (hexapodal arthrobot), includes twistor-pairs in the waist, hip and knee of each leg and walks by pr0gramming fluid pressure in these twistor-pairs at the joints of respective legs in a predetermined controlled sequence. As a result of a predetermined sequence of six controlled variable pressures, this six-legged robot firmly plants three of its legs on the ground for providing stable ground support for walking. The three legs on the ground are propelling the robot forward with walking motion, while the other three legs are lifted and swing forward to an advanced position and are then lowered onto the ground for taking over their support and walking role in their turn, while the first three legs are then being lifted and swung forward to an advanced position, and so forth, for providing a stable forward walking motion. By reversing the sequence of six controlled variable pressures, a stable reverse walking motion is produced.

Abstract: The method and system employ strings of tension actuators in opposed relationship for controlling motions or deflections of jointed members: for example, for controlling the motions of arms, legs and elephant trunks or flexible antennae in robots and for controlling the deflections of beams and columns in frames and structures. These opposed tension actuators are inflated with controlled air pressures which are oppositely varied from a predetermined common-mode pressure P.sub.o (initial fluid pressure level P.sub.o). In other words, as one tension actuator is being inflated with pressure increasing above P.sub.o, the opposed tension actuator is being inflated with pressure decreasing below P.sub.o for producing motion or deflection of the jointed member in one direction, and conversely for producing motion or deflection in the other direction. The opposed tension actuators have their ends anchored to rigid movable plates or struts containing sockets for the respective joints.

Abstract: The method and system employing double-acting, fluid-driven, twistor-pairs as combined flexural supports, joints, torque motors and linear-response angular deflectors in arms and legs of robots. Thus, the twistor-pairs at each joint advantageously serves as hinge or flexural support for the limb supported by the joint and simultaneously serves as double-acting turning motor for moving the portions of the arm or leg supported by the twistor pair. Various jointed-arm or jointed-leg robots, called "arthrobots" are shown embodying the invention. Controllably varying fluid pressure P.sub.1 and R.sub.2 (usually pressurized air) fed into elastic shells forming respective fluid chambers of a double-acting, twistor-pair at each joint, deflects a limb into predetermined predictable angular positions, depending upon these pressures.

Abstract: High pressure, fluid-driven tension actuators, axially contractible upon inflation by a suitable fluid such as compressed air to convert fluid pressure energy into linear contraction displacement, employ nearly spherical shell surfaces when inflated constrained by meridian and parallel elements. The inflatable shells are formed of elastomeric resilient material, and the constraining elements in certain embodiments of the invention comprise a reinforcing, tubular, knitted, fabric sleeve that axially encompasses, conforms to, and is bonded to a resilient, hollow bladder which defines a fluid chamber having at least one conduit connected at a polar location to bladder and sleeve for inflating and deflating the chamber. The parallel and meridian elements for constraining the elastomeric resilient shell include a generally square constraining pattern extending in an equatorial band around the shell upon inflation of the nearly spherical shell.

Abstract: A fluid-driven tension actuator has a pair of end-connection, ring-shaped fittings of relatively large internal diameter with multiple inextensible strands anchored to them and initially extending between them as straight lines oriented at a pitch angle in the range from 60.degree. to 120.degree. forming a network of tension elements constraining the actuator shell and connecting together said two end fittings. These tension element strands define a ruled surface having the shape of an hyperboloid of revolution when the actuator is in its initially deflated (elongated or extended) position. These tension element strands serve to constrain the resilient, flexible, stretchable, elastomeric shell of the actuator which stretches and bulges outwardly into nearly a spherical surface of revolution when the actuator is in its inflated (contracted or retracted) position.

Abstract: Fluid-driven torsional operators for turning rotary valves such as ball valves, butterfly valves and the like and for turning similar devices which swing about a pivot axis, said torsional operators including an inflatable fluid-driven torsional actuator having an axially elongated, flexible, hollow, thin-walled elastic shell defining a fluid chamber with a plurality of inextensible flexible strands bonded to this thin-walled shell. These strands extend between the shell ends and are anchored to axially opposed coupling members which are fixed to and in fluid-tight sealing engagement with the opposite ends of the shell.