Robotic foot

Abstract

A foot (1) is configured to rest on a walkable surface (lb) and comprising: a joint (2) to a prosthesis (la); a contact organ (3) defining a deformable contact area of the foot (1) with the walkable surface (lb); a first body (4) defining the frontal arch of the foot (1), a first end (4a) proximal to the joint (2) and an additional first end (4b); a second body (5) defining the heel of the foot (1), a second extremity (5a) proximal to the joint (2) and an additional second extremity (5b) distal to the attachment (2); an ankle hinge (6) defining a main axis (6a) of mutual rotation between the first body (4), second body (5) and joint (2) and interposed between both first extremities (4a, 4b) and second extremities (5a, 5b). The foot also involves the contact organ (3) connecting the additional ends (4b, 5b); and also first elastic means (7) and second elastic means (8) connecting the first end (4a) and second end (5a) to the joint (2), respectively.

Description

[0001] DESCRIPTION

[0002] ROBOTIC FOOT

[0003] The present invention relates to a robotic foot of the type specified in the preamble to the first claim.

[0004] Specifically, the invention relates to a foot that can be bound, for example, to a limb of a robotic device or to a prosthetic socket by allowing both proper footing on a walkable surface and to perform proper walking. Such a foot can be used in the robotic field and, for example, in prosthetics and / or orthotics.

[0005] The prior art related to robotic feet and in particular prosthetic feet is characterized by a large number of different solutions dictated by the complexity of optimally simulating the structure of such a limb portion, but more importantly the proper movement of the foot and thus the rest of the body.

[0006] Most of the well-known feet are passive elements, that is, they have no motors and are therefore adept at harnessing the movement of the foot itself to store energy to be used to aid walking. They are thus mainly made up of cooperating forefoot and heel portions incorporating forefoot, spring, arch and toe sections and forefoot and heel sections, respectively.

[0007] One of the first solutions is described in US2022054284A1 . It involves the introduction of a foot including a first portion constituting the heel; and a second portion reproducing the forefoot and developing above the heel defining the ankle joint to the lower limb. These portions are basically made up of laminae having an arcuate development so as to flex during walking and namely to accumulate energy during footstrike and then release that energy upon detachment of the foot from the ground.

[0008] An example similar to the above is described in US2008281436A1 and W02006107329A1. In this case there is a first arcuate plate defining the foot (forefoot and hindfoot) and a second arcuate plate constrained to the first plate at the hindfoot and simulating the ankle. Again, the energy storage and release action is achieved by the bending of the plates.

[0009] Another example is presented by US5258038A. In this case, the robotic foot is mainly composed of three parts: a heel element, an ankle element centrally hinged to the heel element, and a forefoot element in turn hinged to the heel element at one end of the forefoot element. It also provides two elastomers / springs connecting the ankle element one to the forefoot element and one to the heel element so that energy can be stored and released according to the mutual rotation between said elements.

[0010] Another example is described in US2013024007A1 . In this case, the foot involves a connecting block to a leg; an arched body defining the part of the foot from the heel basically to the metatarsus and hinged to said connecting block so as to rotate in a dorsiflexion direction and a flexion direction; an end body defining the toes of the foot; and a damper connecting the end body to the connecting block so as to dampen their mutual motion.

[0011] An additional example is described by Mura Domenico et al. in "Exploiting Adaptability in Soft Feet for Sensing Contact Forces," IEEE ROBOTICS AND AUTOMATION LETTERS, IEEE.

[0012] The prior art described comprises some important drawbacks.

[0013] In fact, none of the devices in the prior art have been particularly successful due to the fact that the prosthesis components are too heavy and too rigid and therefore unable to respond adequately to the variety of stresses characteristic of a foot.

[0014] In particular, the known feet have considerable difficulty in responding adequately to external stresses due to, for example, unevenness of the ground and the load resting on the foot. In fact, the known feet are either extremely stiff and therefore unable to properly adjust to various conditions, or particularly loose and therefore not providing a feeling of stability and security for the user.

[0015] An important drawback is, therefore, that the known feet are unable to allow a natural gait and a comfortable, smooth stride.

[0016] Although only for information, we highlight the presence of active feet (see, for example, WO2023204982A2, CN209253236U, CN204562472U) describing the adoption of one or more motors to control foot movements. However, such solutions are of low interest because of the high complexity of implementation and foot control and thus high costs.

[0017] In this situation, the technical task underlying this invention is to devise a robotic foot capable of substantially overcoming at least part of the aforementioned drawbacks.

[0018] Within the scope of said technical task, it is an important purpose of the invention to obtain a robotic foot that is easy to make and use. Another important purpose of the invention is to make a robotic foot that allows a comfortable and fluid stride and thus a natural gait.

[0019] A further purpose of the invention is to have a robotic foot able to adapt to any walkable surface and thus respond adequately to the variety of stresses characteristic of a foot.

[0020] The technical task and the specified aims are achieved by a robotic foot as claimed in the annexed claim 1. Examples of preferred embodiment are described in the dependent claims.

[0021] The features and advantages of the invention are clarified below by the detailed description of preferred embodiments of the invention, with reference to the attached drawings, in which:

[0022] Fig. 1 shows, to scale, a perspective view of the foot according to the invention;

[0023] Figs. 2a-2d illustrate a foot movement sequence, to scale, according to the invention in accordance with a side view;

[0024] Fig. 3 presents, to scale, a side view of the foot, according to the invention under a particular condition of use; and

[0025] Fig. 4 shows, to scale, a rear and partial view of the foot according to the invention.

[0026] In this document, when measurements, values, shapes, and geometric references (such as perpendicularity and parallelism) are associated with words like "approximately" or other similar terms, such as "almost" or "substantially", they are to be understood as excluding measurement errors or inaccuracies due to production and / or manufacturing errors and, above all, as having less than a slight deviation from the associated value, measurement, shape, or geometric reference. For example, if associated with a value, such terms preferably indicate a divergence of no more than 10% of the value itself.

[0027] Furthermore, when terms such as “first”, “second”, “upper”, “lower”, “main”, and “secondary” are used, they do not necessarily identify an order, relationship priority, or relative position, but they can simply be used to distinguish different components more clearly from one another.

[0028] Unless otherwise indicated, "perpendicular”, "transverse”, "parallel”, or "normal”, or other terms of geometric positioning between geometric elements (e.g., axes, directions, and straight lines) are to be understood with reference to their mutual geometric position between corresponding projections. Said projections are defined on a single plane parallel to the lying plane(s) of said geometric elements.

[0029] The measurements and data reported in this text are to be considered, unless otherwise indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533:1975).

[0030] Unless otherwise specified, as reflected in the following discussions, terms such as "processing", "computing", "determination", "calculation", or the like are considered to refer to the action and / or processes of a computer or similar electronic computing device that manipulates and / or transforms data represented as physical, such as electronic quantities of records of a computer plant and / or memories, into other data similarly represented as physical quantities within computer plants, records, or other information storage, transmission, or display devices.

[0031] With reference to the figures, the robotic foot according to the invention is globally indicated with the number 1.

[0032] It is designed to be bound to a prosthesis 1a.

[0033] It should be noted that the term "prosthesis" in this document identifies a limb of a robotic device or preferably a lower limb (particularly in a portion of a lower limb such as a leg). In some cases, the prosthesis 1 a may be a prosthetic socket.

[0034] Foot 1 defines a contact area of foot 1 on a walkable surface 1b when said foot 1 is in use. Walkable surface 1 b can be defined by a ground, rock, road or other structure on which foot 1 can rest. It should be noted that, as described in detail below, the contact area can have a flat profile (i.e. be flat as in Figs. 2a-2d)) or a deformed profile, i.e. being bent and / or curved, due to, for example, its contact with an uneven walkable surface 1 b as shown in Fig. 3.

[0035] Foot 1 defines a front face and a back face.

[0036] Foot 1 includes a joint 2 to join foot 1 to said prosthesis 1 a.

[0037] Joint 2 is configured to integrally constrain foot 1 to prosthesis 1 a.

[0038] It may include an apical portion 21 to join to prosthesis 1 a.

[0039] Said apical portion 21 may define a engagement surface 2a of the prosthesis 1 a and in particular a housing for at least part of the prosthesis 1 a and in particular for at least one end of the prosthesis. Said apical portion may, for example, have a tumbler profile. Said housing and thus apical portion 21 define an axis of insertion 2b of prosthesis 1a into said housing and thus of engagement to foot 1. Said axis of insertion is perpendicular to the contact area defined by the foot and thus to surface 1 b when the foot is in the resting configuration (Fig. 1 and 2b) i.e., when foot 1 defines a contact area with a flat profile and entirely in contact with surface 1 b The apical portion 21 also defines a frontal end 21a and a rear end 21b.

[0040] The frontal end 21a is facing and in detail proximal to the frontal face of foot 1 .

[0041] The rear end 21 b is facing and in detail proximal to the rear face of foot 1 .

[0042] Said ends are on opposite sides with respect to said housing and thus to the apical portion 21 .

[0043] Joint 2 may also include a terminal portion 22 protruding from opposite side of the apical portion 21 to the engagement surface 2a and specifically to said housing.

[0044] The terminal portion 22 protrudes from opposite side to the apical portion 21 normally to the walkable surface 1b at least in resting configuration.

[0045] Portions 21 and 22 are integral to each other. In particular, joint 2 is in one piece.

[0046] Foot 1 includes a contact organ 3 defining said contact area with the walkable surface 1 b; a first body 4 defining at least the frontal arch of said foot 1 , a first end 4a proximal to joint 2 and an additional first end 4b distal from joint 2; a second body 5 defining at least the heel of foot 1 , a second end 5a proximal to the joint 2 and an additional second end 5b distal from the joint 2; and an ankle hinge 6 hinging between them first body 4, second body 5 and joint 2 thereby defining a main axis 6a, preferably one only, of mutual rotation between said first body 4, second body 5 and joint 2.

[0047] In this paper, the terms "proximal" and "distal" are to be understood as near or distant; for example, when we say the first end 4a is proximal to joint 2 and the additional first end 4b is distal from joint 2 we are identifying the fact that the first end 4a is near to joint 2 and the additional first end 4b is distant from joint 2 and specifically at a greater distance from joint 2 than the first end 4a.

[0048] In addition, it is pointed out that the ends of a component can identify two opposite points / areas with respect to said component conveniently along a main axis / trajectory of development of the component.

[0049] The contact organ 3 and thus the contact area are deformable so that it is possible to have a flat or deformed profile for said area. Contact organ 3 is deformable, at least partially, elastically preferably in such a way as to oppose a transition of the contact area from a flat to a deformed profile.

[0050] In particular, contact organ 3 is characterized by the ability to deform in a manner that is not only elastic (i.e. , given by the sub-introduced tendon, rotational constraint spring, and possibly additional rotational constraint additional spring) capable of generating nonlinear stiffening of the sole of foot 1 (i.e., organ 3) due to the load on it.

[0051] It is shown that organ 3 is, at least partially, elastically deformable so that organ 3 itself can oppose a mutual rotation between the first body 4 and the second body 5 and in particular an angular juxtaposition between the additional ends 4b and 5b. Organ 3 connects the additional first end 4b to the additional second end 5b. Preferably, organ 3 and thus the contact area are subtended between said additional ends 4b and 5b.

[0052] Organ 3 can comprise at least one row of segments defining said contact area. In particular, it comprises multiple rows of segments, five in detail, essentially parallel to each other.

[0053] Each row includes a first segment 31, a second segment 32 and optionally one or more intermediate segments 33 interposed between first segment 31 and second segment 32.

[0054] The first segment 31 is bound to the first body 4 at the first additional end 4b. Specifically, it is hinged to the first body 4 by defining a first axis 3a of rotation of the first segment 31 with respect to the first body 4.

[0055] The first axis 3a can be parallel to the main axis 6a.

[0056] The first axis 3a can be parallel to the contact area.

[0057] The second segment 32 is bound to the second body 5 at the first additional end 5b. Specifically, it is hinged to the second body 5 by defining a second axis 3b of rotation of the second segment 32 with respect to the second body 5.

[0058] The second axis 3b can be parallel to the main axis 6a.

[0059] The second axis 3b can be parallel to the contact area.

[0060] Segments 31 , 32 and possibly 33 are mutually hinged and thus capable of rotating with each other. In detail, when the contact area is a flat profile, segments 31 , 32 and 33 are aligned with each other or 180° apart.

[0061] Each row can include a rotational constraint 34 of each segment (31 , 32 and possibly 33) to its adjacent segment 31 , 32 and 33 so as to allow said segments 31 , 32 and 33 to rotate with each other by varying the angular spread between adjacent segments 31 , 32 and 33 and thus deforming the contact area of foot 1 .

[0062] Each rotational constraint 34 defines a third axis of mutual rotation between segments 31 , 32 and 33 preferably parallel to the contact area.

[0063] Each rotational constraint 34 can define an idle, i.e., motorless, rotation between said adjacent segments 31 , 32 and 33.

[0064] Each rotational constraint 34 may comprise two arched surfaces each of which is derived from and thus integral to one of the adjacent segments 31 , 32 and 33 joined by rotational constraint 34 and configured to engage with each other and thus slide reciprocally allowing for a rotation of segment 31 , 32 and 33 and specifically a reciprocal rotation between said adjacent segments 31 , 32 and 33; and appropriately a spring configured to tighten said segments 31 , 32 and 33 together ensuring contact between said arched surfaces.

[0065] Said spring is configured to exert an attractive force between the adjacent segments 31 , 32 and 33 so as to keep their respective arched surfaces always in mutual contact.

[0066] Preferably, the spring works in opposition to a transition of the contact area from the flat profile to the deformed profile. It, therefore, allows organ 3 to oppose rotational juxtaposition between bodies 4 and 5.

[0067] Each rotational constraint 34 may also include at least one stop configured to allow a maximum spread between adjacent segments 31 , 32, and 33 of essentially 180° (plane profile of the contact area)

[0068] Finally, each of at least one row may also include at least one additional segment

[0069] 35 defining an extension of the same row at the first segment 31 on the opposite side to the second segment 32; and thus at least one additional rotational constraint

[0070] 36 of one additional segment 35 to the adjacent segment 31 and 35 (i.e., to the first segment 31 or to an additional segment 35 in the case of multiple additional segments 35).

[0071] Preferably, each row also includes two additional segments 35.

[0072] Additional segment 35 and additional rotational constraint 36 are similar to the above described segments 31 , 32 and 33 and rotational constraint 34 to which we refer for more detail. Thus, the additional rotational constraint 36 comprises two additional arched surfaces each of which is derived from and integral with a segment 35 and / or 31 joined by said additional constraint 36, an additional spring configured to tighten said adjoining segments 35 and / or 31 together and working in opposition to an angular spread of them.

[0073] It is shown that segments 31 , 32 and 33 basically simulate the sole of an anthropomorphic foot; while any additional segments 35 simulate the toes of an anthropomorphic foot.

[0074] In addition, each of at least one row may also include a tendon subtended between two outer segments (identifiable in the first segment 31 and the second segment 32 or, if at least one additional segment 35 is present, in the first segment 31 and the additional segment 35 at a greater distance from the first segment 31 ) and traversing the one or more segments interposed between said outer segments.

[0075] The tendon is to be identified as an inextensible cable subtended between said outer segments and configured to hold itself in tension appropriately independent of the profile of the contact area and thus of the contact organ 3 (preferably tensioned by the spreading of bodies 4 and 5 and / or by the leaning of organ 3 on an uneven support surface 1 b).

[0076] The presence of the tendon and springs of constraints 34 and possibly 36 allows for a contact organ 3 that is flexible for light loads and capable of stiffening when the load increases, supporting the weight of the user. In detail, when the whole foot 1 bears weight, the relative rotation between bodies 4 and 5 subjects organ 3, i.e. , at least segments 31 , 32 and 33, to traction, replicating the elongation of the plantar aponeurosis of the sole of a human foot.

[0077] It is also pointed out that this action is carried out passively. In fact, contact organ 3 tends to assume a deformed shape, e.g., curved, only when subjected to external loads / actions, thanks to the segments that, pushed by the springs, exert a thrust force on the ground; when these external loads / actions cease their action, the springs return the segments to their initial position i.e., with organ 3 having a flat profile.

[0078] Ankle hinge 6 and thus the main axis 6a of rotation are interposed between both first ends 4a and 4b and second ends 5a and 5b.

[0079] Ankle hinge 6 constrains the end portion 22 to bodies 4 and 5 allowing them to rotate towards each other. Ankle hinge 6 is idle.

[0080] The main axis 6a is preferably parallel to the contact area and appropriately to the surface 1 b.

[0081] The first body 4 defines at least the frontal arch of said foot 1 . Therefore, it defines at least the heel of said foot 1 .

[0082] The first end 4a is proximal to the rear face.

[0083] The first end 4a is proximal to the rear end 21 b.

[0084] The additional first end 4b is proximal to the front face and appropriately to the walkable surface 1 b when foot 1 is in use.

[0085] The first body 4 may include a first section defining the frontal arch and subtended between additional first end 4b and main axis 6a; and a second section subtended between first end 4a and main axis 6a.

[0086] Said first and second sections can be arched and, for example, define a cusp at the main axis 6a.

[0087] The first body 4 is preferably in one piece.

[0088] The second end 5a is proximal to the frontal face.

[0089] The second end 5a is proximal to the frontal end 21 a.

[0090] The additional second end 5b is proximal to the rear face and appropriately to the walkable surface 1 b when foot 1 is in use.

[0091] It is shown that, at least in the resting configuration (Fig. 1 and 2b), the first end 4a, the supplementary second end 5b and, preferably, the rear end 21 b stand, with respect to the lying plane of the main axis 6a perpendicular to said contact area, on opposite sides to the second end 5a, the additional first end 4b and, preferably, the frontal end 21 a.

[0092] The second body 5 defines at least the heel of foot 1 . Specifically, it may include a rear body 51 defining said heel of foot 1 and said additional second end 5b; an arm 52 defining the second end 5a; a constraint 53 defining a constraint of rear body 51 with respect to arm 52.

[0093] Thus, the rear body 51 can identify the heel of foot 1 and specifically the second body 5.

[0094] The constraint 53 between rear body 51 and arm 52 can be configured to lably bind rear body 51 to arm 52. In detail, it allows their mutual rotation around an additional axis 5c suitably parallel to the main axis 6a and / or the contact area. In particular, the constraint 53 also includes springback means configured to work in opposition to an angular juxtaposition between rear body 51 and arm 52. Said means of return may include a tension spring.

[0095] The rear body 51 is constrained and to be precise integral to the second segment 32. In this case second axis 3b and supplementary axis 5c can coincide.

[0096] The arm 52 is constrained to ankle hinge 6.

[0097] The arm 52 may comprise a first sector subtended between main axis 6a and second end 5a; and a second sector protruding on the opposite side of the first sector from main axis 6a appropriately toward said additional second end 5b.

[0098] The first sector defines a first longitudinal axis; the second sector defines a second longitudinal axis distinct from the first and preferably inclined with respect to the first longitudinal axis by an angle of, for example, 60° to 120°.

[0099] Foot 1 also includes first elastic means 7 connecting first end 4a to joint 2 and thus configured to oppose mutual rotation between first body 4 and joint 2; and second elastic means 8 connecting second end 5a to joint 2 and thus configured to oppose mutual rotation between second body 5 and joint 2.

[0100] The first elastic means 7 connect the first end 4a to the rear end 21 b and thus are subtended between said ends 4a and 21 b.

[0101] Preferably the first means 7 are configured to oppose an angular offset between first end 4a and rear end 21 b. Said means may include a tension spring.

[0102] The second means 8 connect the second end 5a to the frontal end 21 a and thus are subtended between said ends 5a and 21 a.

[0103] Second elastic means 8 can be configured to oppose an angular deviation between second end 5a and frontal end 21 a. Said means may include a tension spring.

[0104] The elastic constants of 7 and 8 are different from each other so as to generate different resistive torques at different times of the step cycle. In detail, the stiffness of first elastic means 7 is greater than the stiffness of second elastic means 8. More specifically, the ratio of the stiffness of the first elastic means 7 to the stiffness of the second elastic means 8 is substantially greater at 2:1 appropriately 5:1 and to be precise substantially between 5:1 and 20:1 and in detail between 10:1 and 15:1. For example, in one embodiment the ratio of the stiffness of the first elastic means 7 to the stiffness of the second elastic means 8 is 14:1.

[0105] Finally, foot 1 can include at least one end-stop configured to limit angular rotation between first body 4, second body 5, and joint 2.

[0106] In detail said at least one stop block includes a first stop block 9a defining a maximum threshold for a first minimum spread angle between first body 4 and joint 2 appropriately defined between the conjunction of the main axis 6a and first axis 3a of rotation and the first longitudinal axis of the first arm sector 52 with foot 1 in resting configuration. Preferably, the maximum threshold is basically between 120° and 145°.

[0107] First stop block 9a can be integral to first joint 4 and interposed between main axis 6a and first end 4a.

[0108] Said at least one stop block may include a second stop block 9b defining a minimum threshold for said first angle. Preferably, the minimum threshold is basically between 10° and 45°.

[0109] Second stop block 9b can be integral to first joint 4 and interposed between main axis 6a and first supplementary end 4b.

[0110] In the case of first stop block 9a and second stop block 9b, the first angle can vary between said maximum threshold and said minimum threshold.

[0111] Said at least one stop block may include a third stop block 9c defining a minimum opening for a second spread angle between bodies 4 and 5 properly calculated between the conjunction of the main axis 6a to the first axis 3a of rotation and the conjunction of the main axis 6a to the second axis 3b. In detail, said minimum opening is basically between 30° and 75°.

[0112] Third stop block 9c can be integral to first joint 4 and interposed between main axis 6a and second supplementary end 5b.

[0113] The operation of foot 1 previously described in structural terms is as follows. This operation is described in accordance with a step cycle as depicted in the sequence of Figs. 2a-2d.

[0114] At the beginning of a step the foot 1 , dragged, and thus moved, by the prosthesis 1 a, rests the proximal portion at the posterior body 51 (i.e. , at the additional second end 5b) and specifically the second segment 32. Consequently, the resting of the second segment 32 results in a rotational torque around the main axis 6a of rotation of the second body 5, which, therefore, rotates by loading the second elastic means 8. Specifically, in the case of second body 5 comprising rear body 51 , arm 52 and constraint, rear body 51 rotates with respect to arm 52 by loading the springback means of constraint 53.

[0115] Next, segments 31 and possibly 33 and / or 35 contact the walkable surface 1 b. In particular, in the case of irregular walkable surface 1 b (Fig. 3) segments 31 , 32 and if present 33 and / or 35 rotate reciprocally by loading the spring of at least one rotational constraint 34 and / or 36. In addition, the first elastic means 7 begin to load as a result of the rotation, appropriately in the clockwise direction, of the joint 2 around the main axis 6a when at least the second segment 32 are in contact with the surface 1 b.

[0116] At the same time, the detachment of the second segment 32 from the walkable surface 1 b causes the weight of foot 1 to be discharged onto the first segment 31 resulting in the rotation around the main axis 6a of joint 2, which then rotates by loading the first elastic means 7 which then releases that energy upon the detachment of the first segment 31 and thus of the entire foot 1 from the walkable surface 1 b. This creates a second thrust favouring the advancement of foot 1 and its first detachment from surface 1 b.

[0117] It is pointed out that this action can be accentuated by the release of stored energy from at least one rotational constraint 34 and / or 36.

[0118] The robotic foot 1 according to the invention achieves important advantages.

[0119] In fact, the particular conformation of foot 1 and in detail the special use of elastic means 7 and 8 allow shock absorption during load acceptance while ankle hinge 6 allows plantar flexion for a more comfortable and smooth start of the step cycle. In particular, this advantage acquires value especially when it comes to plantarflexion and dorsiflexion, that is, the movements of the foot 1 around the ankle hinge 6 in the sagittal or longitudinal plane.

[0120] This is accentuated by the fact that the innovative mechanics of foot 1 causes a twisting on the joint at ankle hinge 6 during footing similar to that of a human ankle thus providing adequate stiffness for natural stride progression.

[0121] In conclusion, foot 1 behaves and thus provides energy utilization similar to that which characterizes the human foot, with positive mechanical power released during thrust to propel the body forward. As a result, foot 1 provides a natural and stable gait, even over unevenness and obstacles of different shapes and sizes, reducing the compensatory mechanisms and energy consumption that usually characterize the gait that comes with known prostheses. Another particular advantage is that foot 1 allows a much more realistic behavior of the sole of the foot, i.e., the contact organ 3, than the known robotic / prosthetic feet. Another advantage is the absence of actuators or other motors and the high simplicity of foot construction, which also ensure low cost and ease of use. The invention can be modified to create different versions falling within the scope of the inventive concept defined by the claims. In this context, all the details can be replaced by equivalent elements and any materials, shapes and dimensions can be used.

Claims

CLAI MS1. Foot (1 ) configured to rest on a walkable surface (1 b) and including:- a joint (2) to join said foot (1 ) to a prosthesis (1a);- a contact organ (3) defining a deformable contact area of said foot (1 ) with said walkable surface (1 b); a first body (4) defining o the frontal arch of said foot (1 ), o a first end (4a) next to said joint (2) and o an additional first end (4b) distal from said joint (2);- a second body (5) defining o at least the heel of said foot (1 ), o a second end (5a) next to said joint (2) and o an additional second end (5b) distal from said joint (2);- an ankle hinge (6) defining a main axis (6a) of mutual rotation between said first body (4), said second body (5) and said joint (2); said hinge (6) and thus said main axis (6a) being interposed between both said first ends (4a, 4b) and said second ends (5a, 5b); characterized by the fact that said contact organ (3) connects said additional first end (4b) to said additional second end (5b); and by comprising- first elastic means (7) connecting said first end (4a) to said joint (2) and thereby configured to oppose a mutual rotation between said first body (4) and said joint (2); and- second elastic means (8) connecting said second end (5a) to said joint (2) and thereby configured to oppose a mutual rotation between said second body (5) and said joint (2).

2. Robotic foot (1 ) according to claim 1 , wherein said contact organ (3) is at least partially elastically deformable so as to oppose a mutual rotation between said first body (4) and said second body (5) and thus a spacing between said additional ends (4b, 5b).

3. Robotic foot (1 ) according to at least one preceding claim, defining a frontal face and a rear face; wherein said joint (2) comprises an apical portion (21 ) defining a housing for at least part of said prosthesis (1a); wherein said apical portion (21 )defines a frontal end (21 a) and a rear end (21 b); wherein said frontal end (21 a) and said second end (5a) are next to said frontal face; wherein said rear end (21 b) and said first end (4a) are next to said rear face; and wherein said first elastic means (7) connect said first end (4a) to said rear end (21 b) and said second elastic means (8) connect said second end (5a) to said frontal end (21 a).

4. Robotic foot (1 ) according to the preceding claim, wherein said first elastic means (7) and said second elastic means (8) are tension springs.

5. Robotic foot (1 ) according to at least one preceding claim, wherein said second body (5) comprises a rear body (51 ) defining the heel of said foot (1 ) and said additional second end (5b) and an arm (52) defining said second end (5a) and a constraint of said rear body (51 ) to said arm (52) configured to allow mutual rotation between said rear body (51 ) and said arm (52).

6. Robotic foot (1 ) according to the preceding claim, wherein said constraint includes elastic return means configured to work in opposition to an angular juxtaposition between said rear body (51 ) and said arm (52).

7. Robotic foot (1 ) according to at least one preceding claim, wherein said first body (4) comprises a first tract defining said frontal arch and subtended between said additional first end (4b) and said main axis (6a) and a second tract subtended between said first end (4a) and said main axis (6a); and in which said first tract and said second tract are arched and define a cusp at said main axis (6a).

8. Robotic foot (1 ) according to at least one preceding claim, comprising a first stop block (9a) defining a maximum threshold for a first minimum spread angle between said first body (4) and said joint (2), a second stop block (9b) defining a minimum threshold for said first angle, and a third stop block (9c) defining a minimum opening for a second spread angle between said bodies (4, 5).

9. Robotic foot (1 ) according to at least one preceding claim, said organ (3) comprising a plurality of rows of segments, wherein each of said rows of segments comprises a first segment (31 ) hinged to said additional first end (4b), a second segment (32) hinged to said additional second end (5b), at least one intermediate segment (33) interposed between said first segment (31 ) and said second segment (32), and a rotational constraint (34) of two adjacent segments (31 , 32, 33) so as to enable said adjacent segments (31 , 32, 33) to perform a mutual rotation between said adjacent segments (31 , 32, 33) by varying the angular spread between saidadjacent segments (31 , 32, 33) and thereby deforming said contact area; wherein each said rotational constraint (34) comprises two arcuate surfaces each of which is derived from and integral with one of said adjacent segments (31 , 32, 33) joined by said rotational constraint (34) and configured to engage with each other by permitting said reciprocal rotation between said adjacent segments (31 , 32, 33), a spring configured to tighten said adjacent segments (31 , 32, 33) together by ensuring contact between said arcuate surfaces; said spring working in opposition to an angular spread between said adjacent segments (31 , 32, 33).

10. Robotic foot (1 ) according to at least one preceding claim, wherein each of said rows of segments includes at least one additional segment (35) defining an extension of the same row at said first segment (31 ) from the opposite side to said second segment (32) and thus an additional rotational constraint (36) of said additional segment (35) to said first segment (31 ).

Images