Method and system employing strings of opposed gaseous-fluid inflatable tension actuators in jointed arms, legs, beams and columns for controlling their movements

The method for controlling movements of an elongated arm having a longitudinal axis comprising the steps of:

• providing a pivotal mounting between one end of said arm and a support,
• positioning first and second effectively identical fluid-inflatable tension actuators on opposite sides of said arm with said actuators extending generally parallel with the axis and being offset away from the axis on opposite sides of the arm,
• connecting each tension actuator between the support and corresponding positions on the arm on opposite sides of the arm for causing the tension forces of said actuators acting on the arm to be opposed to each other,
• inflating the first and second opposed tension actuators with pressurized gaseous fluid controllably varying by equal pressure increments .DELTA.P in opposite directions from a common pressure level Po for causing the arm to assume various predictable predetermined positions depending directly upon the various values of the pressure increments .DELTA.P,
• said various predictable predetermined positions of the arm varying in a nearly linear relationship in response to the various specific values of the pressure increments .DELTA.P, and
• said arm having a nearly uniform stiffness at all of its positions.

A fluid-pressure actuatable elongated jointed arm having an axis extending along the length of the arm, said arm being capable of reaching in various controlled directions, comprising:

• base means,
• a plurality of elongated links arranged in sequence in end-to-end relationship along the length of the axis of said arm,
• the first of said links in said sequence being positioned near said base means and the last of said links in said sequence being positioned remote from said base means,
• the first of said links having a pivotal mounting to said base means for enabling said first link to swing into various angular positions relative to said base means,
• each successive link in said sequence having a pivotal mounting to the preceding link in said sequence for enabling each successive link to swing into various angular positions relative to the preceding link,
• a plurality of rigid elements,
• respective ones of said rigid elements being connected to the respective pivotal mountings between links,
• said rigid elements projecting out on opposite sides of said axis,
• a first plurality of fluid-inflatable tension actuators connected in sequence in end-to-end relationship with each actuator in the sequence communicating with the next successive actuator forming a first inflatable string of tension actuators,
• a second plurality of fluid-inflatable tension actuators connected in sequence in end-to-end relationship with each actuator in the sequence communicating with the next successive actuator forming a second inflatable string of tension actuators,
• the first string of tension actuators extending along the length of the arm and being offset to a first side of the axis,
• said second string of tension actuators extending along the length of the arm and being offset to a second side of the axis opposite to said first side,
• said first string of tension actuators being attached to the respective rigid elements at attachment positions offset to the first side of the axis,
• said attachment positions being located along the first string at points located between tension actuators in the first string,
• said second string of tension actuators being attached to the respective rigid elements at attachment positions offset to the second side of the axis, and
• said latter attachment positions being located along the second string at points located between tension actuators in the second string.

A fluid-pressure actuatable elongated jointed arm as claimed in claim 18, in which:

• a first pneumatic bridge operates said first and second actuator strings and a second pneumatic bridge operates said third and fourth actuator strings,
• said first and second pneumatic bridges each comprises:
• a source of pressurized air at regulated pressure,
• four pressure-dropping flow resisting components connected to form a four-sided pneumatic bridge having four corners, with an inlet junction and a vent to atmosphere located at two opposite corners of said bridge and wherein there are two junctions located at the respective other two opposite corners of the bridge forming first and second outlets from the bridge,
• said source of pressurized air is connected to said inlet junction for supplying pressurized air at regulated pressure to the bridge,
• the first pressure-dropping flow resisting component located between said inlet junction and said first outlet is equal in effect to the second pressure-dropping flow resisting component located between said inlet junction and said second outlet,
• the third pressure-dropping flow resisting component is located between said first outlet and said vent,
• the fourth pressure-dropping flow resisting component is located between said second outlet and said vent, and
• the first and second outlets of the first bridge communicate with said first and second actuator strings, respectively and the first and second outlets of the second bridge communicate with said third and fourth actuator strings, respectively, and
• there are control means connected to said third and fourth components in both of said pneumatic bridges for varying the pressure-dropping effects of the third and fourth components in each bridge by equal amounts in opposite directions from an initially equal condition.

A fluid-actuatable elongated jointed arm comprising:

• a support for the arm having first and second spaced fastening points,
• a first rigid link extending longitudinally along the longitudinal axis of the arm,
• said first link being pivotally mounted to said support at a first pivot position intermediate said first and second spaced fastening points,
• first and second pneumatically inflatable tension actuators positioned on opposite sides of said link and each having an inlet end and an outlet end,
• the inlet end of the first actuator being connected to the first fastening point,
• the outlet end of the first actuator blocked and being connected to said link at a third fastening point remote from said pivot mounting,
• the inlet end of the second actuator being connected to the second fastening point.
• the outlet end of the second actuator being blocked and being connected to said link at a fourth fastening point remote from said pivot mounting,
• a second rigid link extending longitudinally along the longitudinal axis of the arm pivotally mounted to the arm at a second pivot position remote from said first pivot position,
• fifth and sixth spaced fastening points on said first link on opposite sides of said second pivot position and each being spaced from said second pivot position,
• third and fourth pneumatically inflatable tension actuators positioned on opposite sides of said second link and each having an inlet end and an outlet end,
• the inlet end of the third actuator being connected to the fifth fastening point,
• the outlet end of the third actuator being blocked and being connected to said second link at a seventh fastening point remote from said second pivot position,
• the inlet end of the fourth actuator being connected to the sixth fastening point, and
• the outlet end of the fourth actuator being blocked and being connected to said second link at an eighth fastening point remote from said second pivot connection.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved in various controlled directions, comprising:

• a plurality of rigid elements located at respective positions spaced along said axis,
• each of said elements extending across the axis and having first and second projections projecting outwardly on opposite sides of the axis, all of said first projections being on a first side of said axis and all of said second projections being on the second side of said axis,
• said second side being opposite to said first side,
• each of said elements being oriented generally perpendicular to the neighboring portion of the longitudinal axis at the respective position where the element crosses the axis,
• a plurality of compression-carrying links positioned concentrically along the axis,
• respective ones of said links extending between successive elements,
• each link having a pivotal relationship with the adjacent element,
• said compression-carrying links comprising a plurality of compressive air springs or air actuators of generally oblate form,
• said air springs being constructed so that a decrease of length corresponds to a decrease in internal pressurized volume,
• first and second pluralities of fluid-inflatable tension actuators,
• each of said tension actuators having an inlet end and an outlet end,
• the tension actuators of the first plurality being joined end-to-end for forming a first inflatable string with the outlet end of each actuator in said first string communicating with the inlet end of the next actuator in said first string, and with the outlet end of the last actuator in said first string being blocked,
• the tension actuators of the second plurality being joined end-to-end for forming a second inflatable string with the outlet end of each actuator in said second string communicating with the inlet end of the next actuator in said second string, and with the outlet end of the last actuator in said second string being blocked,
• the first string of tension actuators extending generally parallel with said axis and being offset from said axis on the first side of said axis,
• the second string of tension actuators extending generally parallel with said axis and being offset from said axis on the second side of said axis,
• said first string of tension actuators being fastened to the first projections of said elements with respective fastening connections being located near ends of tension actuators in said first string, and
• said second string of tension actuators being fastened to the second projections of said elements with each respective fastening collection being located near ends of tension actuators in said second string.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions, comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements.

A fluid pressure actuated elongated member having a longitudinal axis and capable of being moved about in various controlled directions, comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means being bendable.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions, comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means being compression actuators positioned between the opposed pairs of tension actuators.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means are compression actuators each having an inflatable flexible bladder, and
• the bladder of each compression actuator encircles a pair of opposed tension actuators.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means are compression actuators each having an inflatable flexible bladder, and
• the bladder of each compression actuator has generally an oblate shape.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions, comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication nd-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means are compression actuators each having an inflatable flexible bladder, and
• the bladder of each compression actuator has generally toroidal shape.

A fluid-pressure actuated elongated jointed member having a longitudinal axis and capable of being moved about in various controlled directions, comprising:

• a plurality of rigid elements extending across the axis at spaced positions along the axis, forming a succession of such elements,
• a plurality of fluid-actuatable tension actuators,
• each of said tension actuators having an inflatable flexible bladder extending between two spaced ends and said ends of each actuator having a passage therein providing communication with the interior of the bladder through each end,
• said tension actuators being arranged in communication end-to-end forming first and second strings of tension actuators,
• said first and second strings being positioned on opposite sides of said axis with respective tension actuators so connected to said rigid elements as to form pairs of opposed tension actuators between successive rigid elements, and
• compression-carrying means positioned concentrically with respect to the axis and between successive rigid elements so as to provide pivotal joints between successive rigid elements,
• said compression-carrying means are compression actuators chamber, and
• said inflatable chambers are in communication with each other for enabling said compression actuators to be deflated for collapsing the jointed member upon concurrent deflation of all tension actuators so to permit compact storage of said jointed member.