Patent Description:
Examples of passive lift devices mounted to the torso of a person configured to support the weight of the arm can be found in <CIT> and <CIT>. Such devices are seen to be limited because they are not able to automatically cut or substantially reduce their assistance when the user intends to rest his/her upper arm at his/her sides, or pick a tool from his/her tool belt. Such devices do not provide a sustained range of position where support torque automatically reduces to zero. Except for a few points of position, these devices will always be applying lifting forces to a user's upper arm, potentially inhibiting motion and creating discomfort during non-working postures when assist is not desired.

In general, passive support devices that are configured to assist a person supporting the weight of a tool are known in the art. Typical passive devices are configured to compensate for gravity under a range of positions using a combination of structural elements, springs, cables and pulleys. The configuration of these devices provides for gravity compensation within a limited range of motion. Additionally, these devices do not allow for a substantially zero torque to be provided. Examples of passive lift assist devices can be found in <CIT> and <CIT>. Such devices are seen to be fairly limited in terms of functionality, as their base must be repositioned every time a user moves to a new location. Examples of a passive lift assist device mounted to the torso of a person to support the weight of a tool include <CIT> and U. Patent Application Publication No. <CIT>. Such devices are seen to be fairly limited because of a bulky frame that does not accurately follow the motions of the user.

The invention described here provides the user a supporting torque to raise his/her upper arm thereby reducing the human shoulder forces and torques required to raise the upper arm. However when the user intends to rest his/her upper arm at his/her sides or pick a tool from his/her tool belt, the device of the invention here automatically reduces the lifting force to zero (or substantially small value) allowing the wearer to move her/his upper arm freely. During non-working postures, zero (or substantially small) torque is desired to allow free motion of person's upper arm or to allow person's upper arm to rest without the impedance of an applied torque from the assist device. This creates a greater overall comfort for user during non-working postures.

In embodiments, there is provided an arm supporting exoskeleton as defined in the appended claims.

<FIG> depicts an embodiment of an arm support exoskeleton (assist device) <NUM>. Arm support exoskeleton <NUM> comprises a shoulder base <NUM>, which is configured to be coupled to a person's trunk <NUM>. In some embodiments of the invention, shoulder base <NUM> is substantially located behind a person (user) <NUM>. Arm support exoskeleton <NUM> additionally comprises at least one arm link mechanism <NUM> that is coupled to shoulder base <NUM>. Arm link mechanism <NUM> comprises at least a proximal link <NUM> and a distal link <NUM> capable of rotation relative to each other along a first rotational axis <NUM>. In some embodiments of the invention, first rotational axis <NUM> is orthogonal to the gravity line <NUM> when person <NUM> in standing upright. The term "gravity line" should be understood to mean the direction in which gravity acts. A first joint <NUM> represents a hinge where distal link <NUM> rotates relative to proximal link <NUM>. Arm support exoskeleton <NUM> additionally comprises at least one arm coupler <NUM> that couples a person's upper arm <NUM> to distal link <NUM> of arm link mechanism <NUM>. Arm coupler <NUM> is depicted in <FIG>. Arm support exoskeleton <NUM> additionally comprises at least one torque generator <NUM> configured to create a torque <NUM> between proximal link <NUM> and distal link <NUM>. A close up view of arm link mechanism <NUM> is depicted in <FIG>. Torque <NUM> in <FIG> and <FIG> show the torque imposed on distal link <NUM> from proximal link <NUM>. As shown in <FIG>, a first angle <NUM> represents an angle between proximal link <NUM> and distal link <NUM>. When first angle <NUM> is smaller than a toggle angle <NUM>, as depicted in <FIG>, torque generator <NUM> generates a torque <NUM> that has the tendency to flex distal link <NUM> relative to proximal link <NUM>. The term "toggle angle" should be understood to mean the angle between a first position (e.g., arm is raised) in which proximal link <NUM> and distal link <NUM> are collinear, and a second position (e.g., arm is lowered) in which the proximal link <NUM> and distal link <NUM> become collinear. The term "flex" should be understood to mean a movement of distal link <NUM> resulting in the decrease of first angle <NUM>, while the term "extend" as used herein should be understood to mean a movement of distal link <NUM> resulting in the increase of first angle <NUM>. The torque <NUM> produces a supporting force <NUM> (shown in <FIG> and <FIG>) onto upper arm <NUM> by arm coupler <NUM>. This reduces the human shoulder forces and torques required to raise person's upper arm <NUM>, and imposes a set reaction force <NUM> and reaction torque <NUM> on shoulder base <NUM>.

When angle <NUM> is larger than toggle angle <NUM> as depicted in <FIG>, torque generator <NUM> provides a substantially small torque between proximal link <NUM> and distal link <NUM>. The term "substantially small torque" should be understood to mean a torque value which does not cause substantial inhibition or discomfort of person's upper arm <NUM>. This allows person <NUM> to move her/his upper arm <NUM> freely. In the Example shown in <FIG>, when a user's upper arm <NUM> is lowered, a position of distal link <NUM> moves past a position of collinear alignment with proximal link <NUM>, and torque generator provides substantially small torque between proximal link <NUM> and distal link <NUM> such that the user can easily maneuver their upper arm <NUM> in this lowered position.

<FIG> depicts another embodiment of arm support exoskeleton <NUM> including of two arm link mechanisms <NUM> connected to shoulder base <NUM>, each including at least one torque generator <NUM> and at least one arm coupler <NUM>. In some embodiments of the invention, distal link <NUM> moves in such a manner that it remains substantially parallel with person's upper arm <NUM>.

In some embodiments of invention, as depicted in <FIG>, shoulder base <NUM> of arm supporting exoskeleton <NUM> comprises a load bearing structure <NUM> coupled to arm link mechanism <NUM> and a coupling mechanism <NUM> that attaches shoulder base <NUM> to person's trunk <NUM>. Load bearing structure <NUM> supports reaction forces <NUM> and reaction torques <NUM> from arm link mechanisms <NUM>. In some embodiments of the invention, as depicted in <FIG>, reaction forces <NUM> and reaction torques <NUM> transfer to person <NUM>. In some embodiments of invention as depicted in <FIG> reaction forces <NUM> and reaction torques <NUM> transfer to a support surface (e.g., ground <NUM>). Various embodiments of load bearing structure <NUM> and coupling mechanism <NUM> are described below.

<FIG>, <FIG>, and <FIG> are presented here to describe various dimensions used herein in the description of load bearing structure <NUM>. <FIG> depicts a front view of person <NUM> including hip width <NUM>, shoulder width <NUM>, and person's frontal plane <NUM>. <FIG> depicts a back view of person <NUM>, including torso height <NUM> and upper arm length <NUM>. <FIG> depicts a side view of person <NUM> including hip depth <NUM> and shoulder depth <NUM>.

<FIG> depict various embodiments of load bearing structures <NUM>. As depicted in <FIG>, in embodiments, load bearing structure <NUM> comprises a back frame <NUM> supporting reaction forces <NUM> and torques <NUM> from arm link mechanisms <NUM> (not shown) and a hip loading belt <NUM>. Hip loading belt <NUM> transfers at least a portion of the reaction forces <NUM> and reaction torques <NUM> to a person's hips <NUM> (shown in <FIG>), resulting in a hip reaction force <NUM>. Back frame <NUM> may also transfer at least a portion of the reaction forces <NUM> to a person's shoulders <NUM> (depicted in <FIG>), as illustrated by shoulder reaction forces <NUM>. Back frame <NUM> can be custom made, or incrementally sized to accommodate person's torso height <NUM>, hip width <NUM>, shoulder width <NUM>, hip depth <NUM>, shoulder depth <NUM>, or any combination thereof. In some embodiments of the invention, hip loading belt <NUM> and back frame <NUM> are constructed as one item.

<FIG> depicts a further embodiment of loadbearing structure <NUM> wherein back frame <NUM> comprises an upper frame <NUM> coupled to arm link mechanisms <NUM> (not shown) and a lower frame <NUM> translationally coupled to upper frame <NUM> to provide desirable torso height adjustment <NUM> for person's torso height <NUM>. Lower frame <NUM> is coupled to, or part of, hip loading belt <NUM>. Reaction forces <NUM> from arm link mechanisms <NUM> are supported by upper frame <NUM>, at least a portion of which are transferred to person's hips <NUM> by hip loading belt <NUM> via lower frame <NUM>, resulting in hip reaction force <NUM>. Upper Frame <NUM> may also transfer at least a portion of said reaction forces <NUM> to person's shoulders <NUM>, as depicted by shoulder reaction forces <NUM>. Upper frame <NUM> can be custom made, or incrementally sized to accommodate person's shoulder width <NUM> and shoulder depth <NUM>. Lower frame <NUM> can be custom made, or incrementally sized to accommodate person's hip width <NUM> and hip depth <NUM>.

<FIG> depicts a further embodiment of load bearing structure <NUM> wherein a back frame <NUM> further comprises a spine frame <NUM> connecting an upper frame <NUM> to a lower frame <NUM>. Spine frame <NUM> is rotatably coupled to lower frame <NUM> on its lower end allowing for rotation of spine frame <NUM> relative to lower frame <NUM> in person's frontal plane <NUM>. Mediolateral flexion motion <NUM> shows the direction of movement between spine frame <NUM> and lower frame <NUM>. Spine frame <NUM> is rotatably coupled to upper frame <NUM> along spine frame axis <NUM>. Spinal twisting motion <NUM> shows the direction of movement between spine frame <NUM> and upper frame <NUM>. Upper frame <NUM> may also translate relative to spine frame <NUM> along spine frame axis <NUM> to provide torso height adjustment <NUM> for person's torso height <NUM>. Degrees of freedom of spinal twisting motion <NUM> between upper frame <NUM> and spine frame <NUM> and mediolateral flexion motion <NUM> between lower frame <NUM> and spine frame <NUM> allow upper frame <NUM> to substantially move in unison with a persons' chest <NUM> (depicted in <FIG>), and lower frame <NUM> to substantially move in unison with person's hips <NUM>.

<FIG> depicts another embodiment of load bearing structure <NUM> wherein a lower frame <NUM> further comprises a lower middle bar <NUM> and two lower corner bars <NUM> wherein each lower corner bar <NUM> can be coupled to lower middle bar <NUM> at various locations on said lower middle bar <NUM> to provide desirable hip width adjustment <NUM> to accommodate person's hip width <NUM>. Lower frame <NUM> may further comprise two lower side brackets <NUM> wherein each lower side bracket <NUM> can be coupled to lower frame <NUM> at various locations on lower frame <NUM> to provide desirable hip depth adjustment <NUM> to accommodate person's hip depth <NUM>. Upper frame <NUM> further comprises an upper middle bar <NUM> and two upper corner bars <NUM> wherein each upper corner bar <NUM> can be coupled to upper middle bar <NUM> at various locations on upper middle bar <NUM> to provide desirable shoulder width adjustment <NUM> to accommodate person's shoulder width <NUM>. Upper frame <NUM> may also comprise two upper side brackets <NUM> wherein each upper side bracket <NUM> can be coupled to upper frame <NUM> at various locations on upper frame <NUM> to provide desirable shoulder depth adjustment <NUM> to accommodate person's shoulder depth <NUM>. Upper frame <NUM> may also comprise hammocks <NUM> spanning curves in upper frame <NUM> to more evenly distribute respective shoulder reaction force <NUM> to person's shoulders <NUM> (depicted in <FIG>). Adjustment of upper side brackets, upper corner bars, lower side brackets, and lower corner bars may include the use of plunger pins, screws, clamps, friction locks, rack and pinions, or any combination thereof.

<FIG> depict various embodiments of the invention where a coupling mechanism <NUM> includes a belt <NUM> that attaches to load bearing structure <NUM> at belt attachment points <NUM> and at least partially encircles person's hips <NUM>. Belt <NUM> can move in unison with person's hips <NUM>. In some embodiments belt <NUM> can change length to allow secure attachment to person's hips <NUM>.

<FIG>, <FIG> and <FIG> depict various embodiments of the shoulder base <NUM>. <FIG> shows a front perspective view of shoulder base <NUM> with person <NUM>. <FIG> shows a rear view of shoulder base <NUM> without person <NUM>. <FIG> shows a rear perspective view of shoulder base <NUM> without person <NUM>. In this embodiment, a coupling mechanism <NUM> includes a chest strap <NUM>. Chest strap <NUM> at least partially encircles person's chest <NUM>. Chest strap <NUM> is mounted to load bearing structure <NUM> at mid-dorsal attachment points <NUM> approximately at the level of person's chest <NUM>. In some embodiments coupling mechanism <NUM> includes at least one anchor strap <NUM> mounted to load bearing structure <NUM> at upper ventral attachment points <NUM> at its first end, and attaches to chest strap <NUM> at its second end. Chest strap <NUM> and anchor strap <NUM> move in unison with person's chest <NUM>. In some embodiments, chest strap <NUM> and anchor strap <NUM> can change length to allow secure attachment to person's chest <NUM>. In some embodiments of the invention chest strap <NUM> is rigid to prevent deflection due to the tightening of anchor straps <NUM>.

<FIG>, <FIG> and <FIG> depict various embodiments of the shoulder base <NUM>. <FIG> shows a front perspective view of shoulder base <NUM> with person <NUM>. <FIG> shows a rear view of shoulder base <NUM> without person <NUM>. <FIG> shows a rear perspective view of shoulder base <NUM> without person <NUM>. In this embodiment, coupling mechanism <NUM> includes at least two shoulder straps <NUM>. Two shoulder straps <NUM> at least partially encircle person's shoulders <NUM>. Each shoulder strap <NUM> is mounted to load bearing structure <NUM> at respective upper ventral attachment points <NUM> on a first end and at lower dorsal attachment points <NUM> on a second end. In some embodiments a sternum strap <NUM> connects to one shoulder strap <NUM> at its first end and another shoulder strap <NUM> at its second end. Shoulder strap <NUM> and sternum strap <NUM> move in unison with person's chest <NUM>. In some embodiments shoulder strap <NUM> and sternum strap <NUM> can change length to allow secure attachment to person's chest <NUM>. In some embodiments shoulder strap <NUM> is mounted to load bearing structure <NUM> at upper ventral attachment point <NUM> on its first end and middle dorsal attachment points <NUM> at its second end.

<FIG>, <FIG> and <FIG> depict various embodiments of the shoulder base <NUM>. <FIG> shows a front perspective view of shoulder base <NUM> with person <NUM>. <FIG> shows a rear view of shoulder base <NUM> without person <NUM>. <FIG> shows a rear perspective view of shoulder base <NUM> without person <NUM>. In this embodiment, coupling mechanism <NUM> includes a vest <NUM> that securely attaches to person's chest <NUM>. Vest <NUM> can move in unison with person's chest <NUM>. In some embodiments vest <NUM> is connected to shoulder base <NUM> by a plurality of vest attachment points <NUM>. In some embodiments, vest attachment points <NUM> attach to chest straps <NUM>, anchor straps <NUM>, shoulder straps <NUM>, sternum straps <NUM>, or any combination thereof.

<FIG> depict embodiments of shoulder base <NUM> wherein coupling mechanism <NUM> can be coupled to a safety harness <NUM> worn by person <NUM> by at least one safety harness attachment point <NUM> without modification of safety harness <NUM>. <FIG> and <FIG> depict an embodiment of the invention wherein vest <NUM> contains at least one safety harness attachment point <NUM>. Safety harness attachment points <NUM> allow vest <NUM> to attach to safety harness <NUM> without modification of safety harness <NUM>. Safety harness attachment points <NUM> may be located on the front, shoulder, or back of vest <NUM>. <FIG> shows a front perspective view of safety harness attachment points <NUM> on the front and shoulders of vest <NUM>. <FIG> depicts a close up back perspective view of the embodiment (without load bearing structure <NUM>), including safety harness attachment points <NUM> on a back and shoulders of vest <NUM>. Safety harness attachment points <NUM> may be formed by velcro loops, buttoned flaps, straps, buckles, clips, clamps, or any combination thereof. <FIG> depicts an embodiment of the invention wherein belt <NUM> contains at least one safety harness attachment point <NUM>. Safety harness attachment point <NUM> allows safety harness <NUM> to be attached to belt <NUM> without modification of safety harness <NUM>. In some embodiments safety harness attachment points <NUM> are located on the sides of belt <NUM>. Safety harness attachment points <NUM> may be formed by velcro loops, buttoned flaps, straps, buckles, clips, clamps, or any combination thereof.

<FIG> depicts the close up view of arm link mechanism <NUM>. In this embodiment first rotational axis <NUM> of first joint <NUM> approximately passes through person's glenohumeral joint <NUM>. <FIG> depicts a back view of this embodiment wherein arm support exoskeleton <NUM> contains two arm link mechanisms <NUM>.

<FIG> and <FIG> depict another embodiment of arm supporting exoskeleton <NUM> wherein arm link mechanism <NUM> comprises at least one horizontal rotation joint <NUM>. Horizontal rotation joint <NUM> allows proximal link <NUM> to rotate relative to shoulder base <NUM> about a second rotational axis <NUM>. Second rotational axis <NUM> is substantially orthogonal to first rotational axis <NUM>. <FIG> shows a rear view of the arm link mechanism <NUM>, wherein the second rotational axis <NUM> is shown to substantially pass through person's glenohumeral joint <NUM>.

<FIG> and <FIG> depict an embodiment of arm support exoskeleton <NUM> that comprises at least one shoulder bracket <NUM> coupled to shoulder base <NUM>. Shoulder bracket <NUM> facilitates a quick connect and disconnect coupling between arm link mechanism <NUM> and shoulder base <NUM>. <FIG> depicts shoulder bracket <NUM> coupling arm link mechanism <NUM> to shoulder base <NUM>. <FIG> shows shoulder bracket <NUM> allowing arm link mechanism <NUM> to be removed from shoulder base <NUM>.

<FIG> depicts another embodiment of arm support exoskeleton <NUM> that comprises at least one shoulder bracket <NUM> coupled to shoulder base <NUM>. Shoulder bracket <NUM> can couple shoulder base <NUM> to arm link mechanism <NUM> in multiple positions to provide desirable shoulder width adjustment <NUM> to accommodate person's shoulder width <NUM>, referenced in <FIG>. In another embodiment not depicted, shoulder bracket <NUM> can couple to arm link mechanism <NUM> in multiple positions to provide desirable shoulder depth adjustment <NUM> to accommodate person's shoulder depth <NUM>.

<FIG> depicts another embodiment of arm supporting exoskeleton <NUM> wherein shoulder base <NUM> comprises at least one shoulder bracket <NUM>. Shoulder bracket <NUM> is rotatably coupled to arm link mechanism <NUM> along a scapular rotation axis <NUM>, wherein said scapular rotation axis <NUM> is substantially orthogonal to gravity line <NUM> when person <NUM> (not shown) is standing upright.

<FIG> depict another embodiment of arm support exoskeleton <NUM>, wherein shoulder base <NUM> is coupled to a shoulder bracket <NUM>. Shoulder bracket <NUM> couples to arm link mechanism <NUM>. Shoulder bracket <NUM> contains a stow joint <NUM> that allows shoulder bracket <NUM> to rotate relative to shoulder base <NUM> (stow joint <NUM> not depicted in <FIG>). When shoulder bracket <NUM> rotates about stow joint <NUM> it may position arm link mechanism <NUM> substantially behind person <NUM>. Shoulder bracket <NUM> can be held stationary about stow joint <NUM> to keep arm link mechanism <NUM> in the desired orientation. <FIG> shows person <NUM> wearing arm supporting exoskeleton <NUM> wherein arm link mechanism <NUM> is in a stowed position that is substantially out of person's workspace <NUM>. The term "person's workspace" should be understood to mean the range of motion of person's upper arm <NUM> that may be utilized during common workplace tasks. <FIG> shows perspective view of shoulder bracket <NUM> in a working position. In the working position arm link mechanism <NUM> is positioned to support person's upper arm <NUM> (not shown). <FIG> shows a perspective of shoulder bracket <NUM> in a stowed position wherein arm link mechanism <NUM> is positioned substantially behind person <NUM> (not shown). In a stowed position a distal link <NUM> remains fully flexed relative to proximal link <NUM> due to torque generator <NUM> acting about first rotational axis <NUM>. This serves to further secure arm link mechanism <NUM> out of person's workspace <NUM>. It should be understood that other joints between arm link mechanism <NUM> and shoulder base <NUM> may be utilized to further secure arm link mechanism <NUM> out of person's workspace <NUM>.

<FIG> depict embodiments of arm supporting exoskeleton <NUM> wherein arm coupler <NUM> further comprises a load bearing coupler <NUM> coupled to distal link <NUM> capable of imposing an upward supporting force <NUM> on person's upper arm <NUM> (shown in <FIG>). In some embodiments load bearing coupler <NUM> comprises a distal link attachment <NUM> that attaches arm coupler <NUM> to distal link <NUM> and at least one arm cuff <NUM> that at partially encircles person's upper arm <NUM> (shown in <FIG>).

<FIG> depicts an embodiment of arm support exoskeleton <NUM> wherein arm coupler <NUM> further comprises an arm coupling mechanism <NUM>. Arm coupling mechanism <NUM> is capable of coupling arm coupler <NUM> to person's upper arm <NUM> (shown in <FIG>). Arm coupling mechanism <NUM> may comprise an element or combination of elements selected from a group consisting of rigid, semi-rigid, or compliant materials preventing separation of said person's upper arm <NUM> (shown in <FIG>) from arm coupler <NUM>.

<FIG> depicts an embodiment of arm coupler <NUM> wherein load bearing coupler <NUM> contains an arm rotation joint <NUM>. Arm rotation joint <NUM> allows arm cuff <NUM> to rotate with respect to distal link <NUM> along arm cuff rotation axis <NUM> substantially parallel to first rotational axis <NUM>. Arm rotation joint <NUM> allows arm cuff <NUM> to provide maximum contact with person's upper arm <NUM> (shown in <FIG>) or compensate for movement discrepancies between distal link <NUM> and person's upper arm <NUM>.

<FIG> depicts an embodiment of arm coupler <NUM> wherein arm coupler <NUM> locations can be adjusted with respect to distal link <NUM>. In some embodiments of the invention, load bearing coupler <NUM> can translate with respect to distal link <NUM> at translation joint <NUM> to allow for arm length adjustment <NUM> of arm link mechanism <NUM> to fit person's upper arm length <NUM> (referenced in <FIG>), or to compensate for any movement discrepancies between distal link <NUM> and person's upper arm <NUM> (depicted in <FIG>). <FIG> depicts another embodiment of translation joint <NUM> wherein distal link <NUM> contains a t-slot mating with load bearing coupler <NUM>. Load bearing coupler coupler <NUM> contains a locking pin <NUM> that fixes the position of load bearing coupler <NUM> relative to distal link <NUM>.

<FIG> depicts an embodiment of arm coupler <NUM> wherein load bearing coupler <NUM> allows for internal and external rotation of person's upper arm <NUM> (shown in <FIG>) with an internal/external rotation joint <NUM>. Internal/external rotation joint <NUM> is located between distal link attachment <NUM> and arm cuff <NUM>. Internal/external rotation joint <NUM> rotates about internal external rotation axis <NUM>. In another embodiment not depicted, sliding contact with person's upper arm <NUM> resting in arm cuff <NUM> allows for rotation about internal external rotation axis <NUM>.

<FIG> depict various embodiments of arm supporting exoskeleton <NUM> wherein torque generator <NUM> comprises a tensile force generator <NUM>. Tensile force generator <NUM>, as shown in <FIG> is coupled to proximal link <NUM> from its first tensile end <NUM> and distal link <NUM> from its second tensile end <NUM>. The tensile force in tensile force generator <NUM> provides a torque <NUM> to flex distal link <NUM> relative to proximal link <NUM> about first rotational joint <NUM>. In some embodiments of torque generator <NUM>, tensile force generator <NUM> comprises a coil spring element <NUM>. In some embodiments of torque generator <NUM> tensile force generator <NUM> comprises a line element <NUM> coupling coil spring element <NUM> to proximal link <NUM>. Line element <NUM> comprises an element or combination of elements selected from a group consisting of wire rope, rope, cable, twine, strap, chain, or any combination thereof. In some embodiments of torque generator <NUM>, line element <NUM> at least partially encircles a pulley <NUM> coupled to distal link <NUM> before line element <NUM> is coupled to proximal link <NUM>. In some embodiments pulley <NUM> does not rotate relative to distal link <NUM>. In some embodiments pulley <NUM> is a curved surface incorporated into distal link <NUM>. <FIG> depicts an embodiment of torque generator <NUM> where coil spring element <NUM> is an extension spring. Coil spring element <NUM> is coupled to line element <NUM> at junction <NUM> and coupled to distal link <NUM> at second tensile end <NUM>.

<FIG> shows an approximate schematic of torque generator <NUM>. Tensile force generator <NUM> is coupled to proximal link <NUM> at a first distance <NUM>. Tensile force generator <NUM> acts about distal link at a second distance <NUM>. Tensile force generator effective length <NUM> is the distance between first distance <NUM> along proximal link <NUM> and second distance <NUM> along distal link <NUM>. Tensile force generator original length is the tensile force generator effective length <NUM> corresponding to a zero value of first angle <NUM>. Tensile force is a function of spring constant, spring preload, tensile force generator original length, and tensile force generator effective length <NUM> at a given value of first angle <NUM>. Torque <NUM> causes distal link to flex relative to shoulder base <NUM>.

<FIG> depicts various embodiments of torque generator <NUM> wherein tensile force generator <NUM> comprises a coil spring element <NUM> and line element <NUM>. Line element <NUM> at least partially encircles a pulley <NUM> coupled to distal link <NUM>. <FIG> depicts an embodiment of torque generator <NUM> where coil spring element <NUM> is an extension spring with a different orientation than shown in <FIG>. Coil spring element <NUM> coupled to line element <NUM> at junction <NUM> and coupled to distal link <NUM> at second tensile end <NUM>. In some embodiments line element <NUM> at least partially wraps around a pulley <NUM> attached to distal link <NUM> before attaching to proximal link <NUM>. <FIG> depicts an embodiment of torque generator <NUM> where coil spring element <NUM> is a compression spring. Coil spring element <NUM> is coupled to line element <NUM> at junction <NUM> and coupled to distal link <NUM> at second tensile end <NUM>. In some embodiments line element <NUM> at least partially wraps around a pulley <NUM> attached to distal link <NUM> before attaching to proximal link <NUM>. <FIG> depicts an embodiment of torque generator <NUM> where coil spring element <NUM> is a compression spring with a different orientation than shown in <FIG>. Coil spring element <NUM> is coupled to line element <NUM> at junction <NUM> and coupled to distal link <NUM> at second tensile end <NUM>. In some embodiments line element <NUM> at least partially wraps around a pulley <NUM> attached to distal link <NUM> before attaching to proximal link <NUM>. It is understood that in all embodiments, instead of coil spring element <NUM>, a gas spring, air spring, elastomer, or any combination that exhibits similar behavior can be utilized.

<FIG> and <FIG> depict an embodiment of torque generator <NUM> wherein proximal link <NUM> comprises an upper bracket <NUM> coupled to tensile force generator <NUM>. The location of upper bracket <NUM> can be adjusted along proximal link <NUM> to adjust torque <NUM> provided by tensile force generator <NUM>. The location of upper bracket <NUM> corresponds to first distance <NUM> in the schematic of <FIG>. In some embodiments, the location of upper bracket <NUM> is adjusted relative to proximal link <NUM> by upper bracket screw <NUM> where upper bracket <NUM> incorporates a threaded feature that mates with upper bracket screw <NUM>. By turning upper bracket screw <NUM>, the location of upper bracket <NUM> is adjusted along proximal link <NUM>. In general, the farther upper bracket <NUM> is from first joint <NUM>, the larger the amplitude of torque <NUM> will be. <FIG> depicts upper bracket <NUM> in an extended position relative to first joint <NUM>, resulting in a large first distance <NUM> (see <FIG>). <FIG> depicts upper bracket <NUM> in a retracted position relative to first joint <NUM>, resulting in a small first distance <NUM> (see <FIG>). <FIG> depicts two plots of torque <NUM> created by torque generator <NUM> as a function of first angle <NUM> for two positions of upper bracket <NUM> described in <FIG> and <FIG>. The torque profile of configuration shown in <FIG> is represented by torque profile <NUM>. The torque profile of configuration shown in <FIG> is represented by torque profile <NUM>. It can be seen torque profile <NUM> has larger amplitude compared to torque profile <NUM>.

<FIG> and <FIG> depict an embodiment of torque generator <NUM> wherein distal link <NUM> comprises a lower bracket <NUM> coupled to tensile force generator <NUM>. The location of lower bracket <NUM> can be adjusted along distal link <NUM> to adjust torque <NUM> provided by tensile force generator <NUM>. The location of lower bracket <NUM> corresponds to preload of tensile force generator <NUM>. In some embodiments the location of lower bracket <NUM> is adjusted relative to distal link <NUM> by lower bracket screw <NUM> where lower bracket incorporates a threaded feature that mates with lower brackets screw <NUM>. By turning lower bracket screw <NUM> the location of lower bracket <NUM> is adjusted along distal link <NUM>. In general the farther lower bracket <NUM> is from first joint <NUM> the smaller the amount of preload will be. <FIG> depicts lower bracket <NUM> in a lengthened position relative to first joint <NUM>, resulting in a small tensile force generator <NUM> preload. <FIG> depicts lower bracket <NUM> in a shortened position relative to first joint <NUM>, resulting in a large tensile force generator <NUM> preload. <FIG> depicts two plots of torque <NUM> created by torque generator <NUM> as a function of first angle <NUM> for two positions of lower bracket <NUM> described in <FIG> and <FIG>. The torque profile of configuration shown in <FIG> is represented by torque profile <NUM>. The torque profile of configuration shown in <FIG> is represented by torque profile <NUM>. Shortened lower bracket torque profile <NUM> has larger amplitude compared to lengthened lower bracket torque profile <NUM>.

<FIG> depicts an important characteristic of the invention where the torque <NUM> provided by tensile force generator <NUM> will automatically remain substantially small when first angle <NUM> is greater than or equal to toggle angle <NUM>. That is, when a user moves their arm from a first position wherein first angle <NUM> is not greater than or equal to toggle angle <NUM>, to a second position wherein first angle <NUM> is greater than or equal to toggle angle <NUM>, tensile force generator <NUM> will automatically shift from a first torque mode wherein a first torque is provided by tensile force generator <NUM> (at the first position of the arm), to a second torque mode (at the second position of the arm) wherein a substantially small torque will be provided by tensile force generator <NUM>. Likewise, when a user moves their arm back from the second position to the first position, the tensile force generator <NUM> will automatically shift from the second torque mode to the first torque mode.

<FIG> shows a configuration where first angle <NUM> is larger than <NUM> degrees, and arm link mechanism <NUM> comprises a protrusion <NUM> located substantially at first joint <NUM>. When first angle <NUM> becomes equal to or greater than toggle angle <NUM>, protrusion <NUM> constrains tensile force generator <NUM> (line element <NUM> of force generator <NUM> as shown in <FIG>) in a position substantially centered about first joint <NUM>. By constraining tensile force generator <NUM>, protrusion <NUM> prevents tensile force generator <NUM> from passing over first joint <NUM>. Torque <NUM> remains substantially zero since the force of the constrained tensile force generator <NUM> is substantially centered about first joint <NUM>. A first angle <NUM> greater than toggle angle <NUM> corresponds to situations where person <NUM> intends to rest his/her upper arm <NUM> at his/her sides, or pick a tool from his/her tool belt. In these situations a substantially small torque <NUM> is desired to allow free motion of person's upper arm <NUM> or to allow person's upper arm <NUM> to rest without the impedance of an applied torque <NUM>. This creates a greater overall comfort of person <NUM> during non-working postures. <FIG> depicts an embodiment of the invention wherein protrusion <NUM> is formed by a first joint pin <NUM> forming first joint <NUM>. <FIG> depicts an embodiment of the invention wherein protrusion <NUM> is a part of proximal link <NUM>.

<FIG> depicts a graph of torque <NUM> created by torque generator <NUM> as a function of first angle <NUM> without protrusion <NUM>. At toggle angle <NUM>, torque <NUM> becomes negative. Negative values of torque <NUM> may impede movement of person's upper arm <NUM> or decrease comfort of person <NUM>. <FIG> depicts a graph of torque <NUM> created by torque generator <NUM> as a function of first angle <NUM> when protrusion <NUM> is created. When first angle <NUM> becomes equal to or greater than toggle angle <NUM>, protrusion <NUM> constrains tensile force generator <NUM>, ensuring that the torque <NUM> remains substantially small (as described in <FIG>). After toggle angle <NUM>, torque <NUM> becomes substantially zero, creating a neutral zone <NUM> for the remainder of first angle <NUM>. Neutral zone <NUM> allows person's upper arm <NUM> to move with a substantially zero applied torque <NUM> within first angle <NUM> greater than toggle angle <NUM>. Neutral zone <NUM> allows person <NUM> to comfortable rest his/her upper arms in a neutral position or to preform secondary tasks such as reaching into pockets or a tool belt.

<FIG> and <FIG> depict an embodiment of arm supporting exoskeleton <NUM> wherein the orientation of proximal link <NUM> can be adjusted and held in place relative to shoulder base <NUM>. Proximal link offset position <NUM> is defined as the orientation of proximal link <NUM> relative to gravity line <NUM> fixed to shoulder base <NUM> when person <NUM> is standing upright. Proximal link offset position <NUM> is adjusted at offset adjustment joint <NUM>, which rotates substantially in the plane of first joint <NUM>. Toggle position <NUM> represents the position of distal link <NUM> when first joint angle <NUM> has become equal to toggle angle <NUM>. By adjusting proximal link offset position <NUM>, toggle position <NUM> is adjusted relative to shoulder base <NUM>. Offset angle <NUM> represents the angle between proximal link offset position <NUM> and gravity line <NUM> when person <NUM> is standing upright. <FIG> shows an embodiment of the invention wherein offset angle <NUM> is relatively small. <FIG> shows an embodiment of the invention wherein offset angle <NUM> is increased. <FIG> shows an exploded embodiment of arm link mechanism <NUM> comprising offset adjustment joint <NUM>. Offset adjustment joint <NUM> allows proximal link <NUM> to rotate relative to shoulder base <NUM>. Offset adjustment joint <NUM> can further lock the rotation of proximal link <NUM> relative to shoulder base <NUM> at a particular position.

<FIG> depicts a graph of torque <NUM> created by torque generator <NUM> as a function of angle of distal link <NUM> from horizontal line <NUM>. Torque profile <NUM> corresponds to a configuration when offset angle <NUM> is zero. Torque profile <NUM> corresponds to a configuration when offset angle <NUM> is fifty degrees meaning the upward torque will not push the person's arm upwardly unless the angle of proximal link <NUM> is raised relative to <NUM> degrees below horizon line <NUM>. It can be observed from this graph that one can move the toggle position by adjusting offset angle <NUM>. Torque generator offset angle <NUM> may be adjusted in order to position toggle position <NUM> at a specific angle relative to horizon line <NUM>. Torque generator offset angle <NUM> may also be adjusted in order to create a torque profile with a specific peak position at a desired angle relative to horizon line <NUM>. When protrusion <NUM> is present a neutral zone <NUM> is formed for both curves for angles of proximal link <NUM> past toggle position <NUM>. When offset angle <NUM> is increased, a larger range of neutral zone <NUM> is created relative to the range of motion of person's upper arm <NUM>.

In some embodiments, lower bracket <NUM>, upper bracket <NUM>, and proximal link offset position <NUM> can all be adjusted to create a desired support profile for torque <NUM>. Arm weight torque profile <NUM> is defined as a torque to counter the weight of person's upper arm <NUM>, forearm <NUM>, hand <NUM>, and a tool <NUM>. <FIG> depicts the profile of torque <NUM> where it matches arm weight torque profile <NUM> in angles substantially above horizon <NUM> and approximately cancels the arm weight torque profile <NUM>. Overhead welding is a good example of an activity of a user that may require such torque. When the absolute angle of the distal link <NUM> is below -<NUM> degrees from horizon <NUM>, the profile of torque <NUM> enters neutral zone <NUM> where torque is substantially zero. This profile of torque <NUM> may be created with a lower bracket <NUM> position or upper bracket position <NUM> that creates a torque <NUM> with a reduced peak amplitude compared to arm weight torque profile. Offset angle <NUM> may then be adjusted to shift support profile of torque <NUM> so that it closely matches arm weight torque profile <NUM> for the desired range of motion. When matched to arm weight torque profile <NUM> a support torque <NUM> of reduced amplitude corresponds to a smaller range of angles in which torque <NUM> matches arm weight torque profile <NUM> and a larger neutral zone <NUM>.

<FIG> depicts another support profile of torque <NUM> with values larger than the arm weight torque profile <NUM> at some angles above horizon <NUM>. This is useful when person <NUM> needs to apply an upward force greater than the combined weight of upper arm <NUM>, forearm <NUM>, hand <NUM>, and tool <NUM>. Drilling into a ceiling is a good example of a user activity that may require such torque. When the absolute angle of the distal link <NUM> is below -<NUM> degrees from horizon <NUM>, the profile of torque <NUM> enters neutral zone <NUM> where torque is substantially zero. This profile of torque <NUM> may be created with a lower bracket <NUM> position or upper bracket position <NUM> that creates a torque <NUM> with any peak amplitude compared to arm weight torque profile <NUM>. Offset angle <NUM> may then be adjusted to shift profile of torque <NUM> so that it exceeds arm weight torque profile <NUM> for the desired range of motion. When adjusted to arm weight torque profile <NUM>, a support torque <NUM> of reduced amplitude corresponds to a smaller range of angles in which torque <NUM> exceeds arm weight torque profile <NUM> and a larger neutral zone <NUM>.

<FIG> depicts another possible support profile of torque <NUM> with values substantially equal to the arm weight torque profile <NUM> at all angles. Manipulating a tool throughout the entire range of motion is an example of a user activity that may require such torque. This profile of torque <NUM> may be created with a lower bracket <NUM> position or upper bracket position <NUM> that creates a torque <NUM> with equal peak amplitude compared to arm weight torque profile <NUM>. Offset angle <NUM> may then be adjusted to align profile of torque <NUM> peak with the peak of arm weight torque profile <NUM>. Below -<NUM> degrees of deviation from horizon <NUM> torque <NUM> enters neutral zone <NUM> (not shown) where torque <NUM> is substantially zero. Even with the full forward range of motion supported, neutral zone <NUM> provides substantially zero torque when person's arm <NUM> extends negatively behind persons trunk <NUM>, such as when a user's hand is reaching for a back pocket.

<FIG> depicts an embodiment wherein load bearing structure <NUM> comprises a back frame <NUM> located substantially behind person <NUM> and a lower extremity exoskeleton <NUM> coupled to back frame <NUM> and also coupled to person's legs <NUM>. Back frame <NUM> is coupled to arm link mechanism <NUM> and supports at least a portion of reaction forces <NUM> and reaction torques <NUM> from arm link mechanism <NUM>. Back frame <NUM> transfers at least a portion of reaction forces <NUM> and reaction torques <NUM> to lower extremity exoskeleton <NUM>. Lower extremity exoskeleton <NUM> transfers at least a portion of reaction forces <NUM> and reaction torques <NUM> to ground <NUM>, resulting in ground reaction forces <NUM>. <CIT>, <CIT>, <CIT>, <CIT>, <CIT> describe some examples of lower extremity exoskeletons that can be coupled to arm supporting exoskeletons <NUM> in accordance with aspects of the invention.

Claim 1:
An arm supporting exoskeleton (<NUM>) configured to be coupled to a person (<NUM>), the arm supporting exoskeleton (<NUM>) comprising:
a shoulder base (<NUM>) configured to be coupled to a trunk (<NUM>) of the person (<NUM>),
an arm link mechanism (<NUM>) coupled to the shoulder base (<NUM>), the arm link mechanism (<NUM>) comprising a proximal link (<NUM>) and a distal link (<NUM>), the distal link (<NUM>) configured to rotate relative to the proximal link (<NUM>) along a first rotational axis (<NUM>) substantially orthogonal to a gravity line when the person (<NUM>) is standing upright,
an arm coupler (<NUM>) configured to couple the distal link (<NUM>) of the arm link mechanism (<NUM>) to an upper arm (<NUM>) of the person (<NUM>),
a tensile force generator (<NUM>) configured to provide a torque to flex the distal link (<NUM>) relative to the proximal link (<NUM>) thereby producing a supporting force onto the person's upper arm (<NUM>), -mm
wherein the tensile force generator (<NUM>) comprises:
a spring element (<NUM>), and
a line element (<NUM>) selected from the group consisting of a wire rope, a rope, a cable, a twine, a strap, a chain, or any combination thereof,
characterized in that the exoskeleton further comprises a bracket (<NUM>) coupled to one end of the line element (<NUM>) and adjustable in location along the proximal link (<NUM>) to adjust a distance between the line element (<NUM>) and the first rotational axis (<NUM>), thereby adjusting the supporting force onto the person's upper arm (<NUM>).