Joint assembly
The present disclosure relates to a joint assembly configured to define a tubular body having a first end, a second end and a passage therebetween. The tubular body is configured for articulation between a first state in which the first end and second end are in a first orientation with respect to one another, and a second state in which the first end and second end are in a second orientation with respect to one another. The body comprises a flexible bladder arranged between opposing supports, each of the bladder and the supports being ring-shaped so as to define an aperture, the respective apertures forming part of the passage. The bladder defines a chamber, and the chamber is partially filled with a fluid which moves within the chamber during articulation of the tubular body from said first state to said second state in order to maintain a constant internal volume of the joint assembly.
1 . An extravehicular activity (EVA) suit joint assembly for a limb or digit, the EVA suit joint assembly comprising a tubular body having a first end, a second end and a passage therebetween, the passage being configured for receiving said limb or digit;
the tubular body comprising a flexible bladder arrangement positioned between opposing supports, the flexible bladder arrangement and the opposing supports being ring-shaped so as to each define an aperture, wherein the respective apertures form part of the passage being configured for receiving said limb or digit;
wherein the tubular body is configured for articulation upon movement of said limb or digit between a first state in which the first end and the second end are in a first orientation with respect to one another, and a second state in which the first end and the second end are in a second orientation with respect to one another; and
wherein the flexible bladder arrangement comprises a bladder which defines a chamber, wherein the chamber is only partially filled with a non-gaseous fluid which moves within the chamber during articulation of the tubular body from said first state to said second state upon movement of said limb or digit.
2 . The EVA suit joint assembly of claim 1 , wherein the non-gaseous fluid comprises a liquid, gel, paste or cream.
3 . The EVA suit joint assembly of claim 1 , wherein the EVA suit joint assembly is configured so as to maintain an interior volume of the tubular body between the first end and the second end at a substantially constant volume during articulation of the tubular body from said first state to said second state, via deformation of the flexible bladder arrangement.
4 . The EVA suit joint assembly of claim 1 , wherein the bladder of the flexible bladder arrangement comprises a membrane that defines the chamber, the membrane being flexible and inextensible.
5 . The EVA suit joint assembly of claim 4 , wherein the membrane comprises a plurality of reinforcing fibres arranged to prevent the membrane from expanding or stretching.
6 . The EVA suit joint assembly of claim 1 , wherein the non-gaseous fluid has a vapour pressure, wherein the vapour pressure of the non-gaseous fluid is 10˜ 10 to 10˜ 7 torr at a temperature of 20 degrees Celsius.
7 . The EVA suit joint assembly of claim 1 , wherein the flexible bladder arrangement is sealingly coupled with the opposing supports.
8 . The EVA suit joint assembly of claim 1 , wherein the tubular body has a longitudinal axis; wherein, during articulation from said first state to said second state, the tubular body bends to define an internal curvature and an external curvature;
wherein each support has a circumference or perimeter, wherein a first section of the circumference or perimeter is intended to be proximal the internal curvature and a second section of the circumference or perimeter opposite the first section of the circumference or perimeter is intended to be proximal the external curvature;
wherein each support is of non-uniform width in a longitudinal direction of the tubular body, wherein a width of each support at said first section is smaller than a width of each support at said second section.
9 . The EVA suit joint assembly of claim 1 , wherein the EVA suit joint assembly is configured such that when the first end is moved relatively to the second end to bend the EVA suit joint assembly, the tubular body contracts at an inside of the bend and expands at an outside of the bend, via deformation of the flexible bladder arrangement.
10 . The EVA suit joint assembly of claim 1 , wherein the EVA suit joint assembly is configured such that when the first end is moved relative to the second end to bend the EVA suit joint assembly, the flexible bladder arrangement is compressed by the opposing supports at an inside of the bend, and the flexible bladder arrangement is decompressed at the outside of the bend, wherein the flexible bladder arrangement has a H-shaped cross-section in use, the H-shaped cross-section being defined by first and second grooves or recesses on opposing sides of the flexible bladder arrangement, the first and the second grooves or recesses each facing one of the opposing supports.
11 . The EVA suit joint assembly of claim 1 , wherein:
a first one of the opposing supports comprises a first interlocking region;
a second one of the opposing supports comprises a second interlocking region; and
the flexible bladder arrangement is configured for cooperation with said first and said second interlocking regions, for location of the flexible bladder arrangement between the first one of the opposing supports and the second one of the opposing supports.
12 . The EVA suit joint assembly of claim 11 , wherein:
the first interlocking region comprises a first lip that runs around the aperture of the first support and extends over an external surface of the first support;
the second interlocking region comprises a second lip that runs around the aperture of the second support and extends over an internal surface of the second support.
13 . The EVA suit joint assembly of claim 1 , wherein: the bladder of the flexible bladder arrangement is a first bladder which defines a first chamber and wherein the flexible bladder arrangement comprises a second bladder which defines a second chamber, wherein an annular septum is arranged between the first and the second bladders, and wherein each of the first and the second chambers is partially filled with the non-gaseous fluid which moves within the respective chamber during articulation of the tubular body from said first state to said second state.
14 . The EVA suit joint assembly of claim 13 , wherein the tubular body has a longitudinal axis; wherein, during articulation from said first state to said second state, the tubular body bends to define an internal curvature and an external curvature;
wherein the annular septum has a circumference or perimeter, wherein a first section of the circumference or perimeter is intended to be proximal the internal curvature and a second section of the circumference or perimeter opposite the first section of the circumference or perimeter is intended to be proximal the external curvature;
wherein the annular septum is of non-uniform width in a longitudinal direction, with a width of said first section being smaller than a width of said second section.
15 . The EVA suit joint assembly of claim 1 , further comprising an annular brace arranged radially inside the flexible bladder arrangement to limit inward radial deformation of the flexible bladder arrangement during articulation of the tubular body from said first state to said second state, the annular brace having first and second brace portions wherein the bladder of the flexible bladder arrangement is a first bladder which defines a first chamber and wherein the flexible bladder arrangement comprises a second bladder which defines a second chamber, wherein an annular septum is arranged between the first and the second bladders, the annular septum having first and second septum portions, and wherein the first and the second septum portions of the annular septum and the first and the second brace portions of the annular brace are integrally coupled, respectively.
16 . The EVA suit joint assembly of claim 1 , further comprising one or more longitudinal strengthening elements which are connected to and extend at least partially over and/or through the flexible bladder arrangement and/or the opposing supports wherein the one or more longitudinal strengthening elements are configured to inhibit separation of the flexible bladder arrangement and the opposing supports and/or to limit flexing of the EVA suit joint assembly in one or more directions.
17 . The EVA suit joint assembly of claim 1 , wherein the tubular body comprises a plurality of said flexible bladder arrangements arranged in series.
18 . The EVA suit joint assembly of claim 1 , wherein the bladder of the flexible bladder arrangement comprises an internal membrane which is annular and runs parallel to inner and outer circumferences of the bladder to split the chamber into a plurality of sub-chambers.
19 . The EVA suit joint assembly of claim 1 , wherein the flexible bladder arrangement is configured for self-healing if the bladder of the flexible bladder arrangement becomes torn.
20 . The EVA suit joint assembly of claim 1 wherein the tubular body forms a glove of an extravehicular activity (EVA) suit, the tubular body of the glove of the EVA suit comprising a plurality of flexible bladder arrangements, each flexible bladder arrangement positioned between opposing supports, the plurality of flexible bladder arrangements and opposing supports of the glove of the EVA suit forming a passageway which is configured for receiving a finger or thumb and being configured for articulation between the first state and the second state upon movement of the finger or thumb.