Patent Application
20250017746
This invention relates to an automated hand. The invention also relates to a cover for an automated hand. The invention also relates to a wrist for an automated hand. The invention also relates to a wrist joint. The invention also relates to an assembly including a wrist joint and an automated hand.
Automated hands are commonly used as prosthetic hands, which may be used to grip objects, shake the hand of another person, and perform other tasks commonly carried out by human hands.
According to one example there is provided an automated hand comprising:
In some examples, the arrangement is such that each connector can rotate in the plane of the palm.
In some examples, the arrangement is such that each connector can rotate in a plane normal to the plane of the palm.
In some examples, the arrangement is such that each connector can rotate about its longitudinal axis.
In some examples, the arrangement is such that each connector can translate when a force is applied to the digit extending therefrom.
In some examples, the arrangement is such that each connector can translate with three translational degrees of freedom.
In some examples, the automated hand is configured to absorb shocks applied longitudinally to the digits.
In some examples, the connector is part of a digit drive that drives flexion and/or extension of the digit.
In some examples, the connector comprises an actuator.
In some examples, the actuator comprises a motor.
In some examples, the connector is connected between an actuator and the digit.
In some examples, the automated hand comprises an actuator in the digit, the actuator driving flexion and/or extension of the digit.
In some examples, the actuator comprises a pivot between the connector and the rigid mount, the connector being rotatable with respect to the mount about the pivot.
In some examples, the pivot comprises one or more pairs of bearing surfaces, one of the bearing surfaces being on or coupled to the rigid mount and the other being on or coupled to the connector, wherein the bearing surfaces of each pair are in close proximity to each other.
In some examples, the resiliently deformable sleeve has one or more apertures formed therein and wherein one of the bearing surfaces of each pair is on a protrusion that protrudes at least partly through a respective one of the apertures.
In some examples, the automated hand further comprises a rigid sleeve between the connector and the resiliently deformable sleeve.
In some examples, the rigid sleeve is configured to couple the connector to the rigid mount.
In some examples, the rigid sleeve comprises one or more twist-lock features to twist lock to complementary twist lock features on a retainer that retains it with respect to the rigid mount.
In some examples, one of the bearing surfaces of each pair is provided on the rigid sleeve.
In some examples, the automated hand further comprises a seal between the connector and the rigid mount to prevent liquid from entering a sealed region within the automated hand.
In some examples, the seal is located near the pivot.
In some examples, the automated hand comprises:
In some examples, the rigid mounts are integral with each other.
In some examples, the rigid mounts are separate from each other.
In some examples, the rigid mount is configured to provide limits to the rotation of the connector with respect to the mount.
In some examples, an inner surface of the rigid mount within which the resiliently deformable sleeve sits is dimensioned to control the maximum lateral rotation of the connector about one or more axes.
In some examples, the automated hand further comprises a barrier around a portion of the connector that is not within the rigid mount, the barrier configured to limit lateral rotation of the connector about one or more axes.
In some examples, an inner surface of the rigid mount includes one or more rotation restraints to limit rotation of the connector about its longitudinal axis.
In some examples, each connector is coupled to the respective digit by an articulated joint.
In some examples, the resiliently deformable sleeve comprises an elastomer, rubber, silicone, or a polymer.
In some examples, the resiliently deformable sleeve comprises polyurethane or a hydrocarbon-, fluorocarbon- or silica-based elastomer.
In some examples, the resiliently deformable sleeve is a thermoset elastomer.
In some examples, the resiliently deformable sleeve is a thermoplastic material, such as a thermoplastic elastomer.
In some examples, the resiliently deformable sleeve is a thermoset rubber.
In some examples, the resiliently deformable sleeve comprises a foamed composition of one or more of the materials recited in the preceding paragraphs.
In some examples, the resiliently deformable sleeve comprises an alloy or blend of two or more of the materials recited in the preceding paragraphs.
In some examples, the resiliently deformable sleeve comprises a material with a DMTA damping factor of between about 0.05 and about 0.8 over a temperature range of about −20° C. to about 100° C.
In some examples, the resiliently deformable sleeve comprises a material with a DMTA damping factor of between about 0.05 and about 0.5 over a temperature range of about −20° C. to about 100° C.
In some examples, the automated hand comprises a material having a resilience of between about 20% and about 60%.
In some examples, the resiliently deformable sleeve comprises a material having a Shore A hardness of between about 10 and about 90.
In some examples, the resiliently deformable sleeve comprises a material having a Shore A hardness of between about 30 and about 60.
In some examples, the resiliently deformable sleeve comprises a material with a Shore A hardness of about 30.
In some examples, the resiliently deformable sleeve comprises a material having a Shore D hardness of between about 40 and about 90.
According to another example there is provided a touchscreen-compatible automated hand comprising:
According to another example there is provided a touchscreen-compatible automated hand comprising:
In some examples, one or more of the conductive attachments comprises a polymer.
In some examples, the polymer is silicone.
In some examples, the one or more of the conductive attachments also comprises a conductive carbon additive.
In some examples, the conductive carbon additive comprises carbon nanotubes.
In some examples, the conductive member is a structural member of the automated hand.
In some examples, the conductive member is a structural member of the digit.
In some examples, the conductive member is part of a linkage of the digit.
In some examples, the one or more conductive attachments comprise a pad and link piece, the pad being located at the exterior of the digit in use and the link piece being in contact with the pad and the conductive member in use.
In some examples, the pad is the conductive attachment defined in any one of the preceding paragraphs.
In some examples, the link piece is a spring that is biased towards contact with the conductive member.
In some examples, the one or more conductive attachments comprise a conductive distal phalanx of the digit.
In some examples, the conductive member is mechanically coupled to the conductive distal phalanx.
In some examples, the conductive path is insulated from terminals of an actuator of the automated hand.
In some examples, the conductive path is insulated from a housing of the actuator.
In some examples, the conductive member and the one or more conductive attachments are configured to, upon one of the conductive attachments touching the touchscreen, cause a touch-sensing array in the touchscreen to sense a change in capacitance within a range indicative of a natural human finger touching the touchscreen.
In some examples, the conductive path terminates at the conductive member.
In some examples, the one or more conductive attachments are configured to be retrofit to an existing, non-touchscreen-compatible automated hand.
According to another example there is provided a method comprising:
In some examples, the conductive member is a structural member of the automated hand.
In some examples, the conductive member is part of a linkage of the digit.
In some examples, one of the conductive attachments comprises a polymer.
In some examples, the one of the conductive attachments also comprises a conductive carbon additive.
In some examples, the conductive carbon additive comprises carbon nanotubes.
In some examples, attaching one or more conductive attachments to the digit comprises:
In some examples, the method includes retrofitting the one or more conductive attachments to a non-touchscreen-compatible automated hand to produce a touchscreen-compatible automated hand.
In some examples, the method further comprises removing a non-conductive part of the non-touchscreen-compatible automated hand and replacing it with one or more of the conductive attachments.
According to another example there is provided an automated hand comprising:
In some examples, the bearing is placed between the worm and a motor that drives rotation of the worm.
In some examples, the bearing is a deep groove ball bearing.
In some examples, the worm is restrained against axial movement relative to the bearing.
In some examples, the automated hand comprises flanges secured to the worm, with one flange at each side of the bearing.
In some examples, one or more of the flanges are welded to the worm.
In some examples, the automated hand further comprises a two-part housing, wherein an outer race of the bearing is held between two parts of the housing.
In some examples, the worm drive further comprises a second bearing at the opposite side of the worm from the bearing.
In some examples, the second bearing is smaller than the bearing.
In some examples, the diameter of the second bearing is about two thirds of the diameter of the bearing or less.
In some examples, the diameter of the second bearing is about one half of the diameter of the bearing.
In some examples, the second bearing is configured to resist radial forces on the worm.
In some examples, the second bearing is configured to provide substantially no resistance to the axial forces generated by the worm.
In some examples, the second bearing is configured to be slidable with respect to the longitudinal axis of the worm.
According to another example there is provided a cover for an automated hand, the cover comprising:
In some examples, the knitted material is configured to have a low resistance to stretching over a first stretch range and a high resistance to stretching over a second stretch range, where the second range is higher than the first range.
In some examples, the resistance to stretching increases sharply between the first stretch range and the second stretch range.
In some examples, the cover body is configured to cover an articulated joint of the automated hand.
In some examples, the cover body is configured to cover a thumb joint of the automated hand.
In some examples, the cover body is configured to cover a joint between the automated hand and a wrist.
In some examples, the cover body is configured to maintain a substantially smooth surface during movement at the joint.
In some examples, the cover is configured to allow movement at the articulated joint over its full range of motion without significantly loading an actuator that drives movement at the articulated joint.
In some examples, the cover is configured to not back drive an actuator that drives movement at the articulated joint when stretched.
In some examples, the knitted material is knitted from elastic thread.
In some examples, the hand coupling is a shaped body having greater rigidity than the cover body material.
In some examples, the hand coupling is made of moulded plastic.
In some examples, the hand coupling at least partly encircles an edge of the cover.
In some examples, the hand coupling is configured to couple to the palm of the automated hand.
In some examples, the cover further comprises a wrist coupling configured to couple to a wrist that the automated hand is coupled to.
In some examples, the cover further comprises a thumb coupling configured to couple to a thumb of the automated hand.
In some examples, the hand coupling is configured to be sandwiched between shell pieces of the automated hand.
In some examples, the wrist coupling is configured to be retained in a groove that encircles the wrist.
In some examples, the cover further comprises one or more additional bodies of a material having greater rigidity than the cover body material to help maintain the shape of the cover.
In some examples, the additional bodies comprise one or more hoops that fully or mostly encircle a part of the cover.
In some examples, the additional bodies are made of moulded plastic.
In some examples, the cover body is configured to allow water to pass through it such that water can drain from a region between the automated hand and the cover.
In some examples, the cover body material is knitted with a sufficiently coarse knit to allow water to pass through the material.
In some examples, the cover body is formed by a 3D knitting process.
In some examples, the cover body comprises a plurality of regions having different properties from each other.
In some examples, the cover body comprises a thumb region that covers at least part of a thumb of the automated hand and a palm region that covers at least part of a palm of the automated hand.
In some examples, two or more of the regions have different stretch characteristics from each other.
In some examples, the thumb region is formed of a less stretchy material than the palm region.
In some examples, two or more of the regions have different coarsenesses from each other.
In some examples, the thumb region is formed of a coarser material than the material of the palm region.
In some examples, the plurality of regions includes a region that is not made of a knitted material.
In some examples, the thumb region is made of a knitted material and the palm region includes a woven material.
In some examples, the cover body has different stretch characteristics in different directions.
In some examples, the cover is configured to approximate the shape of the part of a natural human hand that corresponds to the part of the automated hand that is covered by the cover.
In some examples, the cover body is substantially free of corrugations in use.
In some examples, the cover further comprises one or more reinforced regions configured to lie over protruding features or user input features of the automated hand.
In some examples, the cover further comprises one or more visual indicators configured to lie over user input features of the automated hand.
In some examples, the cover further comprises one or more seams, wherein the seams are sewn, knitted, glued, or joined using bonding tape.
According to another example there is provided a cover for an automated hand, the cover comprising:
In some examples, the structural brace is configured to support the cover body against collapse due to gravity.
In some examples, the cover body is configured to cover an articulated joint of the automated hand.
In some examples, the cover body is configured to cover a thumb joint of the automated hand.
In some examples, the cover body is configured to cover a joint between the automated hand and a wrist.
In some examples, the cover body is configured to maintain a substantially smooth surface during movement at the joint.
In some examples, the cover is configured to allow movement at the articulated joint over its full range of motion without significantly loading an actuator that drives movement at the articulated joint.
In some examples, the cover is configured to not back drive an actuator that drives movement at the articulated joint when stretched.
In some examples, the cover body includes a knitted material.
In some examples, the structural brace comprises a hand coupling configured to couple the cover to the automated hand.
In some examples, the hand coupling is made of moulded plastic.
In some examples, the hand coupling at least partly encircles an edge of the cover.
In some examples, the hand coupling is configured to couple to the palm of the automated hand.
In some examples, the structural brace comprises a wrist coupling configured to couple to a wrist that the automated hand is coupled to.
In some examples, the structural brace comprises a thumb coupling configured to couple to a thumb of the automated hand.
In some examples, the hand coupling is configured to be sandwiched between shell pieces of the automated hand.
In some examples, the wrist coupling is configured to be retained in a groove that encircles the wrist.
In some examples, the structural brace comprises one or more inward brace pieces located inward from the edges of the cover body to help maintain the shape of the cover.
In some examples, the inward braces comprise one or more hoops that fully or mostly encircle a part of the cover.
In some examples, the inward braces are made of moulded plastic.
In some examples, the wrist coupling and/or the thumb coupling are made of moulded plastic.
In some examples, the cover body is configured to allow water to pass through it such that water can drain from a region between the automated hand and the cover.
In some examples, the cover body includes a woven material.
In some examples, the cover is configured to approximate the shape of the part of a natural human hand that corresponds to the part of the automated hand that is covered by the cover.
In some examples, the structural brace is configured to maintain the shape of the cover when the cover is not on the automated hand.
In some examples, the cover body is substantially free of corrugations in use.
In some examples, the cover further comprises one or more reinforced regions configured to lie over protruding features or user input features of the automated hand.
In some examples, the cover further comprises one or more visual indicators configured to lie over user input features of the automated hand.
In some examples, the cover further comprises one or more seams, wherein the seams are sewn, knitted, glued, or joined using bonding tape.
According to another example there is provided an automated hand comprising:
In some examples, the second connection on the palm is spaced apart from the first connection.
In some examples, the first connection is at the base of the palm.
In some examples, the second connection is intermediate the base of the palm and the distal end of the palm.
In some examples, the intermediate location is at least 10% of the length of the thumb from an end of the thumb.
In some examples, the intermediate location is at least 25% of the length of the thumb from the end of the thumb.
In some examples, the thumb comprises two segments connected by an articulated joint.
In some examples, the intermediate location is near the articulated joint.
In some examples, the intermediate location is at the articulated joint.
In some examples, the intermediate location is distal of the articulated joint.
In some examples, the auxiliary support is flexible.
In some examples, the auxiliary support is a support arm.
In some examples, the support arm comprises a resilient material, for example a polymer.
In some examples, the second connection is a pivotal connection.
In some examples, the support arm is configured to connect to both sides of the thumb at the intermediate location.
In some examples, the support arm has a curved shape which can straighten under tension.
In some examples, a side of the support arm facing away from the base of the palm has a concave portion to assist gripping of objects.
In some examples, the support arm is configured such that it does not interfere with the palm or the thumb other than at the first and second connections as the thumb moves through its full range of motion.
In some examples, the auxiliary support is a cord.
In some examples, the thumb has a compliant portion between the first connection and the intermediate location.
In some examples, the first connection comprises a substantially rigid mount in or on the palm.
In some examples, the auxiliary support is frangible and wherein the thumb is connected to the palm via a safety pivot that allows the thumb to pivot freely in the extension direction upon breaking of the auxiliary support.
In some examples, the automated hand further comprises a catch configured to restrict pivoting of the thumb at the first connection when the thumb is under load.
According to another example there is provided an automated hand comprising:
In some examples, the digit is compliant about a second axis corresponding to a flexion-extension axis of the digit.
In some examples, the digit is a thumb.
In some examples, the first axis corresponds to an antepositioning-retropositioning axis of the thumb.
In some examples, the pivotal mount is substantially non-compliant about the second axis.
In some examples, the digit is disposed at or near a first side of the palm and wherein the catch is located between the digit and the first side of the palm.
In some examples, the catch includes a tooth attached to the digit and one or more recesses on the palm, wherein the tooth is driven towards the recess(es) when the digit complies at the compliance location.
In some examples, the tooth is biased away from the recess(es) when the digit is not under load.
In some examples, the load is a load in the extension direction of the digit.
In some examples, the digit comprises a compliant articulated joint at the compliance location.
In some examples, the catch is configured to restrict pivoting of the digit about the first axis when an external force is applied to the digit towards extension of the digit at the compliant articulated joint.
In some examples, the catch is configured to restrict pivoting of the digit about the first axis when a digit actuator drives the digit towards flexion of the digit at the compliant articulated joint.
In some examples, the catch includes a link arm that is coupled to a compliantly mounted gear, the compliantly mounted gear being mounted in a segment of the digit that is on the proximal side of the articulated joint and engaged with a gear on the distal side of the articulated joint.
In some examples, the gear on the distal side of the articulated joint is a drive gear that drives rotation of the digit at the articulated joint.
In some examples, the automated hand further comprises an actuator in the digit on the distal side of the articulated joint, the actuator being configured to drive the drive gear.
In some examples, the tooth is carried on the link arm.
In some examples, the bias is provided by a spring kinematically coupled to the link arm.
In some examples, the proximal portion of the digit comprises a compliant housing at the compliance location or another such compliance location.
According to another example there is provided an assembly comprising a wrist and an automated hand, the assembly further comprising:
In some examples, the coupling clamp comprises a clamp plate configured to be tightened onto the coupling tongue.
In some examples, the coupling clamp comprises one or more screw fasteners for tightening the clamp plate.
In some examples, clamping the coupling clamp onto the coupling tongue pulls the wrist and hand together.
In some examples, the assembly is configured such that the contact interface at which the coupling clamp and the coupling tongue contact each other when the coupling tongue is received in the coupling clamp is at an oblique angle to a longitudinal axis running through the wrist and the automated hand.
In some examples, wherein the coupling clamp and the coupling tongue have complementary faces configured to abut each other and restrict lateral movement of the hand with respect to the wrist.
In some examples, the coupling tongue is located within a pocket and wherein the coupling clamp is configured to fit snugly within the pocket such that the complementary faces include inner faces of the pocket and outer faces of the coupling clamp.
In some examples, the coupling tongue includes one or more ribs and wherein the coupling clamp includes one or more slots configured to fit snugly over the ribs such that the complementary faces include sides of the rib(s) and sides of the slot(s).
According to another example there is provided an automated hand assembly comprising:
In some examples, the biased terminals are spring loaded.
In some examples, the complementary terminals are pads.
In some examples, the pads are concave.
In some examples, the wrist comprises a cable, with the biased terminals or the complementary terminals being located at the end of the cable.
In some examples, the automated hand assembly further comprises a friction fit feature on the cable that configured to couple to a friction fit feature on the hand.
In some examples, the automated hand assembly further comprises a brace on the wrist, the brace configured to prevent electrical decoupling of the terminals when the cable and the hand are mechanically coupled.
In some examples, the wrist has a port formed in it to allow the cable to pass from one side of the wrist to the other.
In some examples, the automated hand assembly further comprises a rotary coupling for coupling the wrist to an arm socket, the rotary coupling configured to allow the wrist to rotate about a longitudinal axis of the arm socket.
According to another example there is provided a wrist for use with an automated hand, the wrist comprising:
In some examples, the locking mechanism further includes a locking button configured to be pushed along a first axis to select the configuration of the locking plate, the first axis being transverse to the direction in which the locking plate moves to enter the recess(es).
In some examples, the first axis lies along the rotational axis of the rotatable wrist joint.
In some examples, the locking plate has a recess for receiving a pin coupled to a locking actuator, the recess having a sloped surface, the plate being moved away from engagement with the recess when the pin rides over the sloped surface.
In some examples, the wrist further comprises a spring configured to bias the plate towards engagement with the recess(es).
In some examples, the one or more recesses are a plurality of recesses arranged radially around the rotational axis of the rotatable wrist joint.
In some examples, the locking plate is configured to move directly towards the rotational axis of the rotatable wrist joint to engage with the recesses.
According to another example there is provided a wrist joint for use with an automated hand, the wrist joint comprising:
In some examples, the rigid axle has a non-planar face adjacent to at least one of the resiliently deformable pieces.
According to another example there is provided a wrist joint for use with an automated hand, the wrist joint comprising:
In some examples, the non-planar face is concave.
In some examples, the non-planar face is configured to provide, for small deviations from the neutral orientation, a higher return torque towards the neutral orientation than a planar face would.
In some examples, the aperture in the rigid sleeve has a plurality of corners with a resiliently deformable piece in each corner.
In some examples, in cross section the perimeter of the aperture includes one or more part-circular arcs and one or more recesses; and each of the one or more recesses is configured to receive one of the one or more resiliently deformable pieces.
In some examples, in cross section the perimeter of the rigid axle includes one or more part-circular arcs and one or more recesses formed in it, wherein:
In some examples, the resiliently deformable pieces are elastomers or suitable polymers.
It is acknowledged that the terms “comprise”, “comprises” and “comprising” may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, these terms are intended to have an inclusive meaning—i.e., they will be taken to mean an inclusion of the listed components which the use directly references, and possibly also of other non-specified components or elements.
Reference to any document in this specification does not constitute an admission that it is prior art, validly combinable with other documents or that it forms part of the common general knowledge.
The accompanying drawings, which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of embodiments given below serve to explain the principles of the invention.
The present specification describes and claims several aspects of automated hands and components for use with automated hands. Any combination of the described and claimed aspects and components may be provided together in an automated hand or in an assembly that includes an automated hand, except when it is clear from the context that the aspects or components are exclusively to be used as alternatives to each other.
Size can be an important consideration in the design of automated hands. Overly large automated hands may be heavy, inconvenient and ill-matched to the user.
The automated hand 1 can have several space-saving features that may allow the automated hand 1 to be made relatively small and compact.
The automated hand 1 has a palm 2. Attached to the palm 2 are digits 3, 4. The palm 2 and digits 3, 4 can be arranged to correspond to the palm and digits of a natural human hand.
In this example, the digits include four fingers 3 and one thumb 4. The fingers 3 of this example are arranged like the four fingers of a natural human hand. The fingers 3 of this example may differ from each other like the fingers of a natural human hand. In particular, the fingers 3 could have different sizes like the fingers of a natural human hand.
The thumb 4 of this example is arranged like the thumb of a natural human hand. The thumb 4 can be movable to oppose the fingers 3 in a similar way to the thumb of a natural human hand.
Overall, the automated hand 1 of this example is arranged to be generally anatomically correct. In other examples, the automated hand 1 may be less anatomically correct and arranged differently from a natural human hand. For example, the automated hand 1 may have more or fewer than four fingers and more or fewer than one thumb.
The fingers 3 of this example are each made up of two sections 31 and 32. Section 31 is referred to herein as the proximal phalanx 31. Section 32 is referred to herein as the distal phalanx 32. The proximal phalanx 31 and distal phalanx 32 are connected by an articulated joint 34, serving as a knuckle. The fingers 3 in this example differ from the fingers of a natural human hand in that a natural human hand has three phalanges—the proximal, intermediate and distal phalanges. In some examples, each finger 3 could have more or fewer than two phalanges, for example it could have proximal, intermediate and distal phalanges like a natural human hand.
As best shown in
The fingers 3 are connected to the palm 2 by respective articulated joints 33. The articulated joints 33 can be provided in respective knuckles 21. As will be detailed further with reference to
The thumb 4 of this example is made up of two sections 42 and 43. Section 43 is referred to herein as the thumb metacarpal. Section 42 is referred to herein as the thumb phalanx. The sections 42 and 43 can be connected to each other by an articulated joint (not shown in
As best shown in
In
Also shown in
The palm 2 in this example is partly covered by a faceplate 25. In the faceplate 25 is user interface panel 23. The user interface panel 23 may have input devices such as buttons. The user interface panel 23 may have output devices such as lights or a display screen. The user interface panel 23 may have a touchscreen serving as an input/output device.
A fascia 22 can also be provided on the palm 2 near the knuckles 21. This may be moulded such that it fits snugly onto the palm 2 and over the knuckles 21.
In
In automated hands, it can be desirable to seal interior portions against water intrusion. It can also be desirable to compliantly mount parts of the hands, such as digits. Digits may be knocked, pulled and pushed in use. Providing compliance to the digit mounts allows them to move somewhat in these scenarios without incurring damage at their point of mounting and without damaging parts of the hand to which they are mounted. This may also allow them to passively conform to the shape of a gripped object and feel more natural, for example in a handshake. However, it may also be desirable to ensure that digits are accurately located and oriented with respect to each other and the rest of the hand, which may be challenging when the digits are compliantly mounted and may require significant “tuning” of the digit control algorithms and/or adjustment of the digit positions after mounting to ensure that they accurately execute desired grips. Additionally, compliant mounting arrangements may in some cases also provide a sealing function and it may be challenging to design compliant elements that provide both good sealing and good compliance. It may also be desirable to mechanically control the limits and other parameters of the compliant movement of the digits more precisely than in other automated hands.
As shown in
Each connector 29 is mounted such that it can move within the mount 27 when a force is applied to the digit that extends from that connector 29. The mount 27 may allow for rotation of the connector 29 in the plane of the palm (i.e. about an axis that is transverse or approximately normal to the plane of the palm), in a plane normal to the plane of the palm (i.e. about an axis that runs approximately laterally through the palm), and/or about the longitudinal axis of the connector 29. The mount 27 may allow for translation of the connector 29 in the plane of the palm or normal to the plane of the palm. Each connector 29 may thereby be mounted with three degrees of translational freedom and three degrees of rotational freedom, although in some examples the connector 29 may be mounted with fewer degrees of rotational or translational freedom.
The mount 27 can be located at or near the front of the palm, as shown in
In the example shown the rigid mount 275 is a separate member from other parts of the palm to which it is attached. In other examples, one or more rigid mounts may be formed integrally with or as part of other structural member(s) of the palm. For example, a modified palm chassis may incorporate the rigid mount. In such an arrangement, the palm chassis may be provided in two parts that are fastenable together to define an aperture for each connector. In another example, one or more palm housing/shell pieces could have outer surfaces that provide the exterior body of the palm and rigid inner surfaces structured to provide the rigid mounts.
The rigid mount or mounts 275 can be made of any suitable material that can provide sufficient rigidity. In some examples, the rigid mount or mounts 275 are made of metal. In some examples, the metal is aluminium.
The rigid mount 275 has within it a sleeve 271. The sleeve 271 can be resiliently deformable such that it can deform by an appreciable amount under forces having magnitudes that would be typically encountered in normal use of the automated hand. These forces could be experienced when a digit attached to the connector 29 is knocked, pushed, pulled, twisted etc. or otherwise experiences shocks or stresses. The resilience of the sleeve 271 can also return it towards its neutral or undeformed state after removal of the forces, although it will be appreciated that in some cases there may be some hysteresis or plasticity associated with the sleeve 271 which may result in it not returning perfectly to the neutral or undeformed state.
Suitable materials for the resiliently deformable sleeve 271 include elastomers, rubbers, silicone, or polymers; polyurethane, hydrocarbon-, fluorocarbon- or silica-based elastomers; thermoset elastomers; thermoplastic materials such as thermoplastic elastomers; and thermoset rubbers; foamed compositions of one or more of these materials; and alloys or blends of two or more of these materials. The sleeve material can be selected to have a Dynamic Mechanical Thermal Analysis (DMTA) damping factor between about 0.05 and about 0.8 over a temperature range of about −20° C. to about 100° C.; or between about 0.05 and about 0.5 over a temperature range of about −20° C. to about 100° C. The sleeve material can be selected to have a resilience of between about 20% and about 60%, which may be measured according to the ASTM D2632 standard. The sleeve material can be selected to have a Shore A hardness of between about 10 and about 90; a Shore A hardness of between about 30 and about 60; a Shore A hardness of about 30; or a Shore D hardness of between about 40 and about 90.
The resiliently deformable sleeves 271 has an aperture for receiving a respective connector 29. The apertures are generally indicated by the arrows 281 in
In the example of
The rigid sleeve 276 can attach to the retainer rings 211 and 278 at the front and rear, respectively, of the connector 29. The connector 29 can also attach to the retainer ring 211, to which the knuckle 21 can attach. The rigid mount 275 can be held between the retainer ring 278 and a flange 274 at the front of the rigid sleeve 276. The rigid sleeve 276 can thus mount the connector 29 to the rigid mount 275 and can mount the knuckle 21 to the connector 29.
A resilient flange 272 of the resiliently deformable sleeve 271 is placed between the flange 274 of the rigid sleeve 276 and the front of the rigid mount 275. A sealing ring 279 is placed between the retainer ring 278 and the back of the rigid mount 275. The sealing ring 279 can provide the main seal that prevents water or other liquid from entering the interior of the hand via the digit mounts 27. In one example, the sealing ring 279 is overmoulded onto the retainer ring 278, although in other examples it may be provided as a separate element. The sealing ring 279 is configured to provide a seal 287 between the rigid mount 275 and the connector 29. In this example, the seal 287 is between the rigid mount 275 and the rigid sleeve 276. The seal 287 can be located near the pivot 288. Because the seal 287 is near the pivot 288, movement of the connector 29 (or rigid sleeve 276) with respect to the rigid mount 275 due to pivoting of the connector is low at the seal 287. The means that the sealing ring 279 does not need to accommodate large variations in the spacing between the sealed elements, thereby improving sealing reliability at this point. The sealing and compliance functions of the automated hand are separated, with the compliance being provided by the resiliently deformable sleeve 271 and the seal being provided by the sealing ring 279. This may allow the compliant mount features to be optimised for compliance without compromising reliability of the seal provided by the seal features and vice-versa.
Also shown in
As shown in
Twist lock features 289a and 289b are provided on the rigid sleeve 276 and retainer ring 278, respectively. In this example, the rigid sleeve 276 has a complex groove 289a into which fit tabs 289b on the inside of the retainer ring 278. In this example, the sealing ring 279 is moulded onto the retainer ring 278. To assemble the connector mounting arrangement, the rigid sleeve 276 is inserted into the resiliently deformable sleeve 271, which is itself inserted into the aperture (labelled 282 in
In other examples, the rigid sleeve 276 may be omitted and one or more of the features of the rigid sleeve 276 described above may instead be provided on the exterior of the connector itself.
The apertures 282 can be dimensioned to set limits on the maximum lateral rotation of the connector (i.e. in the plane of the palm and in a plane normal to the plane of the palm). The wider the aperture 282 is in a given direction, especially at its ends (away from the pivot), the greater the maximum rotation is. The maximum rotations in different directions can be set separately by setting the widths in different directions, i.e. by making the aperture non-circular in cross section. This allows the maximum connector rotation in one direction (e.g. corresponding to splaying of fingers) to be different from rotation in another direction (e.g. corresponding to rotation in the flexion-extension direction).
In an alternative example (not shown in the drawings), a barrier may be provided around a part of the connector that is not within the mount. For example, a rigid ring could be provided around the proximal portion of the connector (i.e. rearward of the mount) to limit the rotation of the connector at this point. This could be dimensioned to control the limits of rotation in each direction.
Worm drives are commonly used in automated hands to drive digit movement. A worm can be placed on a drive motor in the palm or digit. The worm can engage with a worm wheel on the other of the palm and the digit. When using worm drives to rotate worm wheels, axial forces are generated on the worm. Typically, bearings are used on both sides of the worm to resist the axial forces. These bearings resist axial forces in one direction each. To resist the quite large axial forces on the worm, the bearings need to both be quite large. In automated hands, space can be extremely limited and having a large bearing at each end of the worm can hamper the design of compact hands. In particular, it may require a knuckle to be quite large to house the large bearing at the distal end of the worm. Additionally, having two different bearings resisting axial forces requires careful control of the tolerances to axial play of both bearings. It may be advantageous to provide a worm drive that does not require two separate bearings to resist axial forces in both directions along the longitudinal axis of the worm.
Removing the need for a second bearing resisting axial forces may reduce the size of the worm drive, allowing for a more compact hand design. In particular, the size of the gear housing (in this example provided by knuckle 21) may be reduced.
In the example of
The worm 291 can be prevented from moving axially relative to the bearing 212. Axial forces on the worm 291 can be transferred to the bearing 212. In this example, flanges (shown as 284a and 284b in
The second bearing 213 may be free to move axially with respect to the worm 291. In this example, the second bearing 213 is mounted on bearing shaft 299 but is free to slide axially along the shaft 299. The bearing shaft 299 can be fixed to the worm 291, for example by a press fit. This isolates the second bearing 213 from axial forces so that it provides substantially no resistance to them.
The motor 295 could be provided in either the palm or digit of an automated hand. In an exemplary automated hand, the motor 295 is in the palm. In this arrangement, the worm wheel 214 would be connected to a digit to drive rotation of the digit. The digit could have two sections, e.g. proximal and distal phalanges, that are connected to each other by an articulated joint. In the example of
Touchscreen devices are ubiquitous in the modern world, however these typically rely on electrical properties of a natural human body to detect a touch. Users of automated hands may be unable to operate these touchscreens if their automated hand does not have special arrangements to approximate the relevant electrical properties of a natural human hand or body. For example, capacitive touchscreens can detect a touch by the effect of a human body acting as a parasitic capacitance to ground. Automated hands may be unable to provide sufficient parasitic capacitance to ground to register a touch on these touchscreens.
Some prosthetics have sought to address the issue of operating capacitive touchscreens by providing a conductive connection between a fingertip of the automated hand and the user's body. This can be difficult to implement given the different types of stumps and partial hands that the prosthetics are to be fitted to. These designs may also require dedicated conductive wires and the like to be incorporated at the time of manufacture, making them unsuitable for retrofit applications. There may also be safety concerns relating to electro-static discharge with these designs. These designs are typically avoided in automated hands.
Some automated hands provide conductive substance such as paint, glue or the like at the tip of a finger. This can provide a conductive path from the tip to electrical components such as a motor in the hand, via a complex electrical path that may include dedicated wires electrically connecting the conductive substance to a terminal of the electrical component. These conductive substances can be relatively hard, meaning that they may only make contact with the screen over a very small contact area. This means that touches may not be reliably recognised, especially when the angle of the finger on the screen is non-optimal. They may also require an electrical connection between the conductive substance to a motor terminal in order for them to work.
Some automated hands provide a conductive coating or tip on a finger that does not electrically connect to other finger components. In these designs, the conductive coating or tip itself is intended to emulate the electrical properties of a natural human body. Without connection to any other conductive members of the hand, it may be difficult to provide sufficient parasitic capacitance to reliably register a touch on a capacitive touchscreen.
The finger 3 includes a proximal phalanx body 301 made up of pieces 301a and 301b and a distal phalanx body 302. The proximal phalanx body 301 can house other components of the proximal phalanx 31. The proximal phalanx body 301 can be connected to the knuckle 21 via the digit drive assembly 215. The proximal phalanx body 301 has toothed sockets 308a and 308b, the teeth of which engage with teeth of the output wheels 226a and 226b (shown in
The finger 3 also includes attachments 35a, 304 and 305. The attachments 35a, 304 and 305 can be configured to attach to the finger 3 at the distal phalanx 32. One or more of the attachments 35a, 304 and 305 can be conductive and can provide a conductive path from the exterior of the finger 3 to a conductive member within the hand. In the example of
The attachment 304 in this example is a retainer clip that is connected to or integral with the digit pad 35a and can be inserted into the distal phalanx body 302 to retain the digit pad 35a on the distal phalanx 32. The digit pad 35a in this example is moulded over the attachment 304. The retainer clip can clip to the distal phalanx body 302. The retainer clip 304 may or may not be conductive. In the example of
The attachments can include a link piece that provides a link between a conductive attachment that is at the exterior of the digit, such as the pad 35a, and a conductive member within the hand. In the example of
In alternative examples to the one shown in
In some examples the digit can be made compatible with a touchscreen by a process of retrofitting the one or more conductive attachments to a digit that is not compatible with a touchscreen. In these examples, it may be advantageous to place the conductive attachment(s) in contact with an existing member of the automated hand. Automated hands that are not compatible with touchscreens may nonetheless have members within them that can, in combination with the conductive attachment(s), emulate the effect of a human touch on a touchscreen. For example, automated hands may have metal members within them that can add sufficient capacitive loads on capacitive touchscreens to register a touch. Using existing conductive members of the automated hand may avoid the need to add special conductive members within the hand, such as dedicated conductor wires or coatings. The conductive member within the hand can be a structural member of the hand. Using a structural member of the hand may avoid the need to electrically connect the conductive member(s) at the exterior of the digit to electrical components such as motors. In the example of
The conductive path can be insulated from electrical components of the hand. For example, the conductive path can be insulated from a housing of an actuator for the digit, such as a motor. The conductive path can be insulated from the terminals of the actuator. The insulation may be by way of substantially non-conductive materials or coatings or by one or more air gaps. The conductive path may be insulated from the body of the user by a non-conductive socket used to attach the automated hand to the user's limb. In one example, the conductive path terminates at the conductive member, e.g. link arm 306. In other examples, the conductive member can be connected to another conductive member to extend the conductive path. The other conductive member may also be a structural member of the hand. For example, the link arm 306 may be in conductive contact with the knuckle 21. The knuckle 21 can be made of metal, for example aluminium.
The conductive member can be selected or designed such that, in combination with the one or more conductive attachments, it has sufficient effect on the properties measured by a touchscreen to be detected. This may be a function of the parasitic capacitance introduced when finger 3 (or other digit) touches the touchscreen. For example, the finger 3 can be designed such that the effect of the conductive attachment(s) and conductive member on the capacitance measured by a capacitive touchscreen is within the range indicative of a human touch. In other examples, the finger 3 can be designed such that the effect on one or more detection currents applied to a touchscreen surface is within the range indicative of a human touch. It has been found that touchscreens can be quite sensitive to changes in the material in the conductive path.
The finger 3 (or other digit) may be designed for use with various types of touchscreens, including capacitive touchscreens. Capacitive touchscreens include surface capacitance or projected capacitance varieties. Within the category of projected capacitance touchscreens, there are mutual capacitance and self-capacitance touchscreen technologies.
Surface capacitance touchscreens detect a touch from changes in detection currents applied to the surface of a touchscreen at different locations, typically the corners. If a member with sufficient parasitic capacitance touches the screen, the detection currents will change as charge flows into the member. The finger 3 (or other digit) may be designed contribute sufficient parasitic capacitance to register a touch on a surface capacitance touchscreen.
Self-capacitance touchscreens work by detecting changes in capacitance between an array of electrodes and ground. When a member with sufficient parasitic capacitance touches the screen, an increase in capacitance between an electrode near the touch point and ground is detected due to the addition of the member's parasitic capacitance to ground in parallel to that of the electrode's. The finger 3 (or other digit) may be designed to contribute sufficient parasitic capacitance to register a touch on a self-capacitance touchscreen.
Mutual capacitance touchscreens work by detecting changes in capacitance between pairs of electrodes in an electrode array. When a member with sufficient parasitic capacitance touches the screen, a decrease in capacitance between a pair of electrodes that intersect near the touch point is detected due to the member drawing off charge from the electrode pair to ground. The finger 3 (or other digit) may be designed contribute sufficient parasitic capacitance to register a touch on a mutual capacitance touchscreen.
As noted above, the design of the touch-sensing arrangement may be particularly well suited to be retrofit to an existing hand to render it compatible with touchscreens. An exemplary retrofitting method may involve a preliminary procedure of removing one or more parts of the non-compatible hand to make room for the conductive attachment(s). With reference to the exemplary conductive attachments 35a and 305 of
A method of constructing a touchscreen-compatible hand includes attaching one or more conductive members to the digit and placing the attachment(s) in contact with a conductive member of the automated hand. The conductive member can be the one or more conductive member(s) discussed above, for example the link arm 306, and the conductive attachments can be the one or more conductive attachments discussed above, for example the pad 35a and spring 305 or the conductive distal phalanx. The method can be performed as a retrofit method, in which case the preliminary procedure of removing parts from a non-compatible hand may be performed, or as part of the initial manufacture of a touchscreen-compatible hand, in which case the preliminary procedure need not be performed.
In the example in which the conductive member is the link arm 306 and the conductive attachments are the pad 35a and the spring 305, the method can include inserting the spring 305 into the distal phalanx 32 and placing part of the spring in contact with the link arm 306. Due to the resilient nature of the spring, it can be biased against the link arm 306. The pad 35a can then be attached to the distal phalanx and in contact with the spring 305. There is now provided a conductive path from the pad 35a at the exterior of the digit to the link arm 306 via the spring 305.
As noted above, the thumb 4 of the hand 1 may be configured for use with a touchscreen, in addition to or as an alternative to one or more of the fingers 3 being configured for use with a touchscreen. In these examples, the thumb can be provided with an attachment that contacts a conductive member in the thumb 4. One example is described with reference to
The conductive attachment(s) of the thumb can be configured to attach to distal end of the thumb, which may be a distal phalanx in a thumb that has a plurality of phalanges. One or more of the attachments can be conductive to provide a path from the exterior of the thumb 4 to a conductive member within the hand.
In the example of
The thumb pad 35b can be attached to the thumb tip body 421. The thumb pad 35b can extend through the thumb tip body 421 to make contact with the thumb body 422. The thumb body 422 can be made of a conductive material, for example a conductive polymer or plastic. The thumb body 422 can be made of Nylon. The thumb body 422 can be made of a polymer or plastic with a conductive additive. The conductive additive can be carbon. The carbon can be in the form of carbon nanotubes. In alternative examples, the thumb body 422 may be made of a metal such as aluminium. The thumb body 422 can make contact with the gear housing 425, which can be made of a conductive material such as a metal, for example aluminium. The conductive path in this example can be provided by the thumb pad 35b, thumb body 422 and gear housing 425.
In the examples above, the finger pads 35a and thumb pad 35b are provided only at the ends of the digits, i.e. on the distal phalanx 32 of each finger 3 and on the thumb phalanx 42. In alternative examples, one or more additional finger pads could be provided elsewhere on the fingers 3, e.g. on the proximal phalanges 31. Similarly, one or more additional thumb pads could be provided elsewhere on the thumb 4, e.g. on the thumb metacarpal 43 and/or the auxiliary support 45. In alternative examples, a finger pad could be attached to both the distal phalanx 32 and proximal phalanx 31 of a finger and span the interphalangeal joint 34. Similarly, a thumb pad could be attached to the thumb phalanx 42 and one or both of the thumb metacarpal 43 and the auxiliary support 45.
Automated hands may use covers to improve aesthetics by covering mechanical joints and providing a more natural-looking surface. These may also protect the joints and other workings of the hand from debris and protect foreign objects from getting caught in the joints or other workings. Covers typically cover a thumb joint and/or thumb metacarpal. These may be made of moulded elastomer material (e.g. rubber) with a concertina-like structure to allow for bending of joints. However, these look unnatural. Also, they have relatively high resistance to movement and high resilience which causes them to tend to return strongly to their neutral shape. This may make it hard to hold the position of the thumb joint without the use of non-backdrivable gears. The corrugations in the concertina structure may have a tendency to get caught in things. The moulded elastomer covers are also expensive and difficult to customise or redesign because any change would require a full retooling of the moulds for the whole cover (which is typically moulded in one piece).
Some covers may use a woven material. Woven materials can be quite stiff and resistant to initial stretching from their neutral state. Woven materials also tend to only have substantial stretch in one direction. The tight weaves of some woven materials may also prevent trapped water or other liquid from draining out through the cover. Because it can be difficult to waterproof around such a cover, water may get in behind the cover and be unable to drain out.
Some fabric covers may be unable to hold their shape well, resulting in the cover folding or sagging under its own weight when it is not pulled taut. This may result in an unnatural look and feel and may also increase the chance of the cover being caught in something.
The body 411 can be made up of one or more regions. In the example of
The fabric material of the cover body 411 can be made to allow water to flow through the material due to gravity alone. This allows any water that may get behind the cover 41 to naturally drain from the automated hand. This may be achieved by using a coarse knit or weave in the fabric.
The different regions of the cover body 411 can have different properties from each other. For example, they could have different coarsenesses, different fabric constructions (e.g. knitted or woven), different stretch characteristics, different knit/weave axes, or different thread types. For example, the thumb region 413 can be made a less stretchy fabric than the palm region 412. The fabric of the palm region 412 can have a more dense (i.e. less coarse) stitch than the fabric of the thumb region 413. In one example, the thumb region 413 are both knitted. In another example, the thumb region is made of a knitted material and the palm region 412 is made of a woven material.
In some examples, the cover body 411 can be made of a polyester fibre, a polyethylene fibre such as ultra-high molecular weight polyethylene (UHMWPE) fibre, fibreglass, nylon fibre, spandex fibre, or combinations thereof. In some examples, the thumb region 413 is made from a combination of polyester fibre, UHMWPE fibre, and fibreglass and the palm region 412 is made from a combination of nylon fibre and spandex fibre. In other examples, the thumb region 413 and the palm region are both made from polyester fibre.
The cover 41 in
The fabric of the cover 41 can be designed with different stretch characteristics in different directions. This may help it to maintain its shape, which approximates the part of a natural human hand corresponding to the part of the automated hand that it covers. Selecting appropriate levels of stretch in each direction may help to prevent parts of the hand from sagging or folding and presenting a corrugated surface, allowing the surface of the cover to stay smooth despite movement of the thumb.
The cover 41 can have additional bracing on the cover body 411 to help maintain the shape of the cover 41. This may support it against sagging, folding, or otherwise collapsing under its own weight due to gravity. The bracing can be made of brace pieces that are more rigid than the fabric of the body. The brace pieces can encircle part of the cover body 411 to form a structural hoop, either at an edge of the body 411 or inward from the edge. The bracing can be made of polymer, such as plastic. In some examples, the bracing can be made of pieces of moulded plastic. These are shown at 414, 415 and 416 in the example of
The brace pieces can be attached to the cover body 411 in various ways, for example they could be taped and/or moulded onto the cover body 411. In one example, the brace 414 (optionally made up of pieces 414a, 414b, 414c, 414d) at the edge of the cover that couples to the palm can be taped to the cover body. In one example, the braces 415 and/or 416 can be overmoulded onto the cover body 411. Specifically, the brace 415 can be overmoulded onto the fabric at the distal edge of the thumb region 413 and the brace 416 can be overmoulded onto the fabric at the proximal edge of the palm region 412.
The cover 41 can cover a wrist joint that connects the automated hand to an arm coupling. In the example of
In some examples, the cover 41 could extend over the knuckles and articulated joints between the fingers and the palm. In some examples, the cover could extend back beyond the wrist to cover the connection of the wrist to a user's forearm. In other examples, the cover 41 could cover less of the palm and thumb than the example of
As noted above, the braces 414, 415, 416 can encircle parts of the cover body 411 to form hoops. The hoops can be continuous or broken. In one example, the hand coupling/brace 414 is broken into pieces. This may assist in pulling the cover 41 over the hand when attaching or removing it. As best shown in
The cover 41 may also have reinforced sections positioned to lie over protrusions or user input features of the hand, including over wrist release buttons or the like. The cover 41 could also have visual indicators in these locations such as differently coloured patches or symbols.
Some automated hands have wrist components permanently or semi-permanently attached to the palm of the hand. This may require a user to remove the entire prosthesis when the hand needs to be removed, for example for servicing.
Some wrists for automated hands have springs placed about the wrist joint for returning the joint to a neutral angle. These can be quite bulky due to the placement of springs outside of the wrist joint. Spring-based wrist joints can also be difficult to assemble because they require the springs to be pre-loaded (i.e. compressed) during assembly. These designs can also be quite heavy due to the added weight of the metal springs. Other wrists may use elastomers to return the joint to a neutral angle. Current designs using elastomers may provide only weak return forces near the neutral angle, which may prevent the wrist from returning fully to the neutral position and may make the wrist too loose or “floppy” under no load or low loads on the wrist.
Some automated hands connect to electrical components such as batteries on the user's arm using a cable that passes through the wrist. This can be difficult to connect and disconnect. Some automated hands have plug-type electrical connectors between the wrist and the hand. In these designs, a dedicated electrical release mechanism may need to be operated to release the electrical connection, in addition to the mechanical release required to decouple the hand from the wrist.
Some wrists for automated hands can be selectively locked against rotation about the flexion-extension axis. These may have locking features on the hand itself and locking buttons located in the region of the hand. Some locking buttons and the like can be difficult to operate, especially if the locking elements are not perfectly aligned.
Some wrists may screw or bolt directly to the hand. This may require space within the hand to be dedicated to screw or bolt holes.
The wrist 5 includes first coupling for coupling to a user's arm and a second coupling for coupling to the automated hand, with a wrist joint in between the couplings. In this example, the first coupling is a socket coupling 51 that couples to an arm socket on the user's remaining arm portion. This is connected to the joint body 52 which, together with the hand coupling 53, forms a wrist joint. The wrist joint in this example is articulated so that the hand coupling 53 can rotate in the flexion-extension direction at the joint. The joint body 52 is rotatably connected to the socket coupling 51 in this example, allowing the joint body 52 to rotate about the longitudinal axis of the arm socket, i.e. for pronation and supination of the hand. The wrist 5 can be selectively locked against flexion and extension at the wrist joint by the wrist lock 55.
Also shown in
In
In the example of
A friction fit feature can also be provided on each of the electrical connector 56 and the part of the automated hand that the wrist connects to (in this example, on the palm chassis 26). In the example of
A brace 563 is provided on the wrist 5 to bear on the back of the electrical connector 56 and brace it in place on the electrical connector of the hand when the wrist 5 is mechanically coupled to the hand. This may prevent the electrical coupling between the wrist and the hand being broken while the wrist 5 and hand are mechanically coupled.
The mechanical coupling between the wrist and the hand uses a clamping arrangement. In the example of
The side faces of the coupling clamp 57 can be place in contact with complementary faces on the coupling tongue to restrict lateral movement between the coupling tongue 261 and the coupling clamp 57. The coupling clamp 57 can fit snugly within one or more pockets 262 and 263 of the coupling tongue 261, with the sides of the pocket providing the complementary faces that restrict movement. The pockets 262 and 263 can have ribs within them that fit snugly within slots 571 formed in the coupling clamp, also providing complementary faces that restrict lateral movement. The outward-facing sides of the pockets 262 and 263 engage with the inward-facing sides of the clamp 57. These provide the contact interface between the coupling clamp 57 and the coupling tongue 261 when clamped together. This interface is at an oblique angle to the wrist-hand longitudinal axis and causes the wrist 5 and palm chassis 26 to be pulled together when the coupling clamp 57 is tightened onto the coupling tongue 261.
The coupling clamp 57 can include a clamp plate 573. The clamp plate 573 is movable with respect to the rest of the clamp 57 to tighten and loosen. The clamp plate 573 can have screws passing through it that can be tightened and loosened to tighten and loosen the clamp plate 573, and therefore the coupling clamp 57, on the coupling tongue 261.
Also shown in
In the example of
As shown in
Resiliently deformable pieces 525 are located in the aperture 524 and go between the sleeve and the rigid axle. When the rigid axle rotates within the aperture, the resiliently deformable pieces 525 are deformed. Due to their resilience, they act to force the rigid axle back towards a neutral orientation in which forces on the axle are balanced. The resiliently deformable pieces 525 can be made of elastomers or suitable polymers. For example, the resiliently deformable pieces 525 could be made of silicone or rubber. The resiliently deformable pieces 525 can be located in the corners of the aperture 524 and can be shaped to fit within the space between the rigid sleeve and the rigid axle in the neutral axle orientation.
Also shown in
In
In the example of
A lock rod 535 that forms part of the locking mechanism is also shown. In this example, the lock rod 535 passes through the rigid axle 531 and extends along the wrist joint rotational axis 58. The wrist lock 55 can be operated by pushing the buttons 533a and 533b along the axis 58. This may make operation of the wrist lock 55 easier for a user than placing the wrist lock in another location such as on the hand coupling 53 or on the hand itself, because in those cases the wrist lock actuator (e.g. button or the like) will move when the wrist rotates, rather than always remaining in one place. It may also be particularly intuitive for a user to lock rotation of the wrist joint by pushing the buttons 533a, 533b along the wrist joint rotation axis 58.
The locking mechanism also includes a locking member which engages with the lock base 526. In this example, the locking member is locking plate 534. The locking plate 534 is shown inserted into one of the recesses, in this case the recess that corresponds to the neutral position.
An alternative wrist joint is shown in
The recesses 532′ and 524′b are recessed in the sense that they correspond to parts of the perimeter of the rigid axle 531′ and aperture in the rigid sleeve that are recessed from hypothetical circles on which the respective part-circular arcs lie. In other words, the recesses 532′ of the rigid axle 531′ are formed within the perimeter of a hypothetical circle on which the part-circular arcs 531′a of the rigid axle 531′ lie. The recesses 524′b of the aperture in the rigid sleeve are formed outside of the perimeter of a hypothetical circle on which the part-circular arcs 524′a of the aperture lie.
The recesses 524′b can be part-circular, for example approximately or somewhat less than half-circular. As shown in
The locking mechanism is shown in more detail in
The rod 535 has recesses 551 on it. These can be engaged with by a detent member in the detent housing 552. For example, the detent housing may include a spring and a ball detent biased towards the rod 535 by the spring.
To operate the wrist lock, a user operates the locking actuator—for example by pressing the button 533b to lock the wrist. The pin 537 will move from right to left (in the orientation of
To unlock the wrist, a locking actuator is operated in the opposite direction (e.g. by pushing button 533a). The pin 537 the rides over the sloped surface of the recess 538 and drives the locking plate up out of the recess 527 in the lock base 526.
This mechanism may ensure that the locking actuator is easy to actuate (e.g. the buttons 533a, 533b are easy to push) even when the locking plate 534 is not aligned with a recess 527 of the lock base 526.
In another example, a further alternative wrist may be provided that does not have a wrist joint allowing for flexion and extension in the wrist. This may save space in the wrist, resulting in a shorter wrist. Due to the omission of the wrist joint, a single body can serve as the hand coupling and joint body and be rotatably connected to the socket coupling. This wrist may be similar to the wrist 5 in other respects.
Some automated hands have digits that correspond to fingers and thumbs of natural human hands. The thumbs may be able to rotate in an antepositioning-retropositioning direction to move in and out of opposition with the fingers. When executing certain grips, it can be important to ensure the thumb is accurately positioned and does not rotate undesirably in the antepositioning-retropositioning direction. For this reason, some automated hands may include a thumb lock for preventing this rotation. Some thumb locks may lock a thumb against rotation in the antepositioning-retropositioning direction when it has rotated to a certain point, for example into opposition with the fingers. These automated hands are limited to only a small number of different positions at which the thumb can be locked. Also, the locking of the thumb is not in response to a function performed by the thumb that would require locking, like executing a grip. Other hands may use engagement surfaces located on the back of the thumb and on a locking member located behind the thumb. These restrict rotation of the thumb when the thumb is pushed back onto the locking member to bring the engagement surfaces together. It may be desirable to provide an automated hand that doesn't require a locking member behind the thumb.
Some automated hands include a thumb that is mounted to the palm only at the base of the thumb. When a force is applied to the thumb, producing a torque at the connection point. The connection point has to withstand this torque itself and counteract the entire applied force. The closer to the base of the palm the thumb is connected, the longer the lever arm provided by the thumb is and the greater the torque at the connection point is for a given applied force. It may be desirable to provide an additional support to the thumb that resists a component of the applied force, may improve the resistance of the thumb to breaking, and may allow the thumb connection to be lower on the palm than it otherwise could be. Moving the thumb connection point lower down on the palm may save space in the palm.
Some automated hands include a thumb that is substantially non-compliant but that is attached to an actuator that is compliantly mounted in the palm. It may be advantageous to separate the compliance of the thumb from the mounting to the palm. This may improve sealing of the palm, improve structural strength of the thumb mount, and reduce the space needed in the palm for the thumb mount.
Also shown in
An auxiliary support 45 provides an additional structural connection between the thumb 4 to the palm 2. The auxiliary support 45 may help to support the thumb 4 and reduce torque on the connection 46 at base of the thumb 4 when the thumb 4 is forced back.
The auxiliary support 45 extends from an intermediate location along the thumb 4 to a connection point 201 on the palm 2. The intermediate location on the thumb is placed between the ends of the thumb 4, for example in from either end by at least 10% of the length of the thumb, or by at least 25% of the length of the thumb 4. The auxiliary support 45 can connect to the thumb at or near an articulated joint 44 between two segments of the thumb 4. In the example of
The connection point 201 on the palm 2 is spaced apart from the connection 46 to which the base of the thumb 4 is connected. This allows the auxiliary support 45 to act on the thumb 4 along a line that is largely tangential to an arc swept out by the thumb when it is forced back under load. The connection point 201 on the palm 2 is between the base of the palm 2 and the distal end of the palm 2 (where the fingers attach).
The auxiliary support 45 can be flexible. The auxiliary support 45 can bend or extend to allow the thumb 4 to comply under loads. In some examples, the auxiliary support 45 can be made of nylon. The auxiliary support 45 of
The connection 201 of the support arm to the palm can be a pivotal connection, allowing the support arm to pivot with little resistance when the thumb pivots in the antepositioning or retropositioning directions. Alternatively, the support arm could be sufficiently flexible to bend to accommodate pivoting of the thumb 4. The support arm 45 can connect to the thumb 4 at both sides for a secure connection on the thumb. This may also avoid twisting the thumb 4 about its longitudinal axis when load is applied. To enable this, the support arm 45 can be forked at the thumb end. The support arm 45 can be curved so that it can straighten out under tension, allowing compliance to the thumb 4 to a load. The “upper” side of the support arm 45, i.e. the side facing away from the base of the palm 2, can have a concave portion to assist gripping of objects. The support arm 45 can be arranged so that it does not interfere with the palm or thumb anywhere across their full range of motion.
In an alternative example, the auxiliary support could be a cord.
The thumb 4 can have a compliant portion between its connection 46 to the base 202 of the palm 2 and the intermediate portion at which the auxiliary support 45 connects to allow the thumb 4 to move back under load. In the example of
The auxiliary support 45 may be frangible such that it can reliably break under a certain tension. The pivotal connection of the thumb 4 to the palm 2 can be a safety pivot that allows the thumb to pivot freely in the extension direction when the auxiliary support 45 breaks.
A catch 49 is also provided to restrict pivoting of the thumb 4 in the antepositioning-retropositioning directions when the thumb 4 is under load. This will be described in more detail with reference to
Further details of the catch 49 and thumb 4 are shown in the exploded views of
Attached to the motor is a motor-driven gear 424 which drives the gear 432 which is located in the gear housing 425. The gear 432 is compliantly mounted so that it can comply under applied loads. In particular, the gear 432 can rotate somewhat within the housing 425. The bushing 434 is placed over the gear 432 and the gear 432 is retained between the metacarpal housing parts 431a, 431b. In this example, the motor-driven gear 424 is a worm and the gear 432 is a worm wheel. When assembly, the axle 495 fits within the socket 433 of the gear 432 to rotationally couple the link arm 491 to the gear 432. An end of the spring 494 is looped over the pin 493 and is housed within the recess 437 on the metacarpal mount part 431a. The pin 493 on the link arm 491 can extend through an aperture in the metacarpal housing part 431a into the tooth 492. The pin 493 is retained in place by the retainer ring 497. The end of the pin 493 extends into the aperture 436 on the block 435. This controls the limits of movement of the pin 493 and thereby the limits of extension of the tooth 492 and rotation of the gear 432. The finger 498 also controls the limit of extension of the tooth 492 by engaging with the metacarpal housing part 431a.
In operation, the actuator 423 can rotate the gear 424 which is engaged with the gear 432. The gear 432 serves as a fixed gear that the gear 424 can move around as it rotates, except that the gear 432 is not completely fixed and can rotate a small amount. When the gear 424 moves anticlockwise over the gear 432, the thumb 4 extends. When the gear 424 moves clockwise over the gear 432, the thumb 4 flexes. When the gear 424 drives the gear 432 for flexion, the gear 432 can rotate somewhat against the bias of the spring 494. This rotation of the gear 432 drives rotation of the link arm 491 and causes the tooth 492 to move into the recesses on the palm, thereby locking the thumb 4 against pivoting in the antepositioning-retropositioning direction. In an alternative example, a compression spring 494′ can be located on the palm side of the finger 498′, as shown in
When the thumb 4 is forced back (i.e. towards extension), the phalanx part of the thumb 4 rotates back with respect to the metacarpal part. This causes the gear 424 in the phalanx part to push on the compliant gear 432. The compliant gear 432 complies and rotates anticlockwise, thereby rotating the link arm 491 and driving the tooth 492 to move into the recesses on the palm, locking the thumb against pivoting.
With reference to the axes of
The thumb catch described herein may help to maintain an accurate thumb position when executing grips. It may also keep the thumb at a fixed angle about the axis 461 when flexing the thumb to help accurately bring it together with fingers of the hand. It may also allow more precise control of the thumb angle about the axis 461. The thumb catch arrangement may also avoid the need for catches or rotation lock components at the back of the thumb, resulting in a more anatomically correct hand.
While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.
| Number | Date | Country | Kind |
|---|---|---|---|
| 781940 | Nov 2021 | NZ | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/NZ2022/050135 | 11/1/2022 | WO |
