ARTIFICIAL FOOT

Abstract

The invention relates to a prosthetic foot comprising a base body having a front sole region, a heel body having a rear sole region, and a slot configured to receive at least one spring element, in particular at least one leaf spring, the spring element configured to be pushed or inserted into the slot. In a disposed state, the spring element engages in the base body and the heel body such that the heel body is spring mounted relative to the base body.

Claims

1. A prosthetic foot comprising: a base body having a front sole region; a heel body having a rear sole region; and a slot configured to receive at least one spring element, the spring element configured to be pushed or inserted into the slot, wherein, in a disposed state, the spring element engages in the base body and the heel body such that the heel body is spring mounted relative to the base body.

2. The prosthetic foot according to claim 1, wherein: the spring element is connected centrally to the base body using one of an adhesive connection, a screw connection, a latching connection, or a press fit connection.

3. The prosthetic foot according to claim 1, wherein: the spring element is mounted in at least one of an opening in a front region of the base body or an opening in a rear region of the heel body so as to be movable in a longitudinal direction of the spring element.

4. The prosthetic foot according to claim 1, wherein: the base body comprises a forefoot body and a mounting body, the front sole region located on an underside of the forefoot body, and the mounting body is configured to receive an adapter.

5. The prosthetic foot according to claim 4, wherein: the forefoot body is flexibly connected to the mounting body via a web.

6. The prosthetic foot according to claim 1, wherein: the heel body is connected to the base body via a web, wherein the web is configured such that the web surrounds the spring element at least in sections.

7. The prosthetic foot according to claim 1, wherein: the front sole region has a convex shape at least in sections, over at least 40% of a contact surface of the front sole region.

8. The prosthetic foot according to claim 1, wherein: the base body comprises a stop element which extends downward at an angle of 30 to 60 degrees to a longitudinal axis of the spring element, and which rests on the spring element.

9. The prosthetic foot according to claim 1, wherein: the spring element, in the disposed state, is disposed in a plane that is substantially parallel to an adapter plane, or is disposed in a plane that rises toward a front of the prosthetic foot.

10. The prosthetic foot according to claim 1, wherein: the base body comprises a rear stop which is spaced apart from the heel body by a gap.

11. The prosthetic foot according to claim 1, wherein the prosthetic foot is produced in an additive process.

12. The prosthetic foot according to claim 1, wherein: at least two of the base body, the heel body, a forefoot body, a mounting body, a web that flexibly connects the forefoot body to the mounting body, or a stop element that rests on the spring element formed in one piece.

13. The prosthetic foot according to claim 1, wherein: the spring element comprises fiber-reinforced plastic.

14. The prosthetic foot of claim 1, wherein: the spring element comprises GFRP or CFRP.

15. The prosthetic foot of claim 1, wherein: the spring element is a leaf spring.

16. The prosthetic foot of claim 2, wherein: the spring element connected centrally to the base body is connected to the base body at a point within a region of the spring element that comprises 10% of a total length from a center of the spring element.

17. The prosthetic foot of claim 9, wherein: the adapter plane is defined by mounting points on the base body that are configured to mount an adapter.

18. The prosthetic foot of claim 10, wherein: the gap is at least 1 cm.

19. The prosthetic foot of claim 11, wherein: the additive process is a 3D printing process.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The invention is described in the following using several design examples, which are explained in more detail with the aid of illustrations. The figures show:

[0037] FIG. 1 a first prosthetic foot, wherein the base body and the heel body are connected via a web;

[0038] FIG. 2 a second prosthetic foot, in which the base body and heel body are connected only via a leaf spring;

[0039] FIG. 3 a third prosthetic foot;

[0040] FIG. 4 a longitudinal section through the first prosthetic foot of FIG. 1;

[0041] FIG. 5 a first perspective view of the prosthetic foot of FIG. 1 (from above);

[0042] FIG. 6 a second perspective view of the prosthetic foot of FIG. 1 (from below);

[0043] FIG. 7 an exemplary side view of a leaf spring;

[0044] FIG. 8 a fourth prosthetic foot.

DETAILED DESCRIPTION

[0045] In the following description, the same reference numbers are used for parts that are the same or have the same effect.

[0046] FIG. 1 shows a side view of a prosthetic foot 1 according to the invention. Said foot is substantially composed of two elements, namely a heel body 30 and a base body 60. In the design example shown in FIG. 1, the heel body 30 and the base body 60 are connected to one another via a heel web 35. The heel web extends substantially horizontally. The base body 60, heel web 35 and heel body 30 form an integral unit, which is produced in an additive process, for example by 3D printing.

[0047] The heel body 30 comprises a slot 32 having a corresponding slot opening, into which a leaf spring 50 is inserted. The leaf spring 50 extends in the longitudinal direction of the prosthetic foot 1, substantially horizontally to a ground plane BE (FIG. 4). The length of the leaf spring 50 corresponds substantially to the total length of the prosthetic foot. It is only 15% shorter than the total length of the prosthetic foot 1. The leaf spring 50 reinforces the heel web 35 and provides a spring mounting of the heel body 30.

[0048] The rear part of the base body 60 with a rear stop 67 is noticeably spaced apart from the heel body. There is gap there, having a gap height D of at least 1 cm. In the shown design example, the gap height D is 2 cm. The gap allows free movement of the heel body 30 in vertical direction. In the event of overloading, the heel body 30 strikes the rear stop 67, and thus prevents the heel web 35 and/or the leaf spring 50 from being subjected to excessive loads that could possibly cause it to break.

[0049] The base body 60 can be functionally subdivided into further elements. These are a forefoot body 70, a mounting body 80, a web 65 and a stop element 62. All of these elements are integrally connected to one another. The web 65 provides an elastic connection between the mounting body 80 and the forefoot body 70. On its upper side, the mounting body 80 holds an adapter 88. The web 65 extends substantially from top right to bottom left and merges smoothly into the forefoot body 70. The web 65 has an average thickness of approx. 2 cm. According to the invention, the web 65 can have an average thickness of 1 to 5 cm, in particular 1 to 3 cm.

[0050] A front sole region 61 is located on the underside of the forefoot body 70. A corresponding rear sole region 31 is located on the underside of the heel body 30. In the design example shown in FIG. 1, the rear sole region 31 and the front sole region 61 are provided with a rubber coating to ensure good ground contact.

[0051] The forefoot body 70 further comprises a cap 77 having a receptacle (see FIG. 4) into which the leaf spring 50 projects. In the center of the prosthetic foot 1, at the level of the web 65, the leaf spring 50 is screwed to the base body 60 with two screws 9 (see also FIG. 6). The screws 9 secure the leaf spring 50 against displacement in longitudinal direction. At its ends, the leaf spring 50 is not connected to the prosthetic foot and projects loosely into the openings provided there, so that, for example, the cap 77 can move in longitudinal direction relative to the leaf spring 50 when walking. The leaf spring 50 is supported with respect to the forefoot body 70 via two transverse webs 71, 71 (see FIG. 3). The first, front transverse web 71 and the second, rear transverse web 71 are integral components of the forefoot body 70. They can in turn be configured as spring elements or have a resilient effect.

[0052] The stop element 62 forms the upper region of the base body 60 and extends substantially parallel to the web 65. The web 65 and the stop element 62 are spaced apart from one another. This results in a gap of approx. 1 cm, which extends upward toward the rear beyond the load line and/or construction line of the prosthetic foot 1. The gap extends substantially (approx. +/15%) in a 45 degree angle to the longitudinal axis of the leaf spring 50.

[0053] A damper 3 which rests directly on the upper side of the leaf spring 50 is disposed in the front lower region of the stop element 62. The second transverse web 71 starts at this location on the underside of the leaf spring 50. The second transverse web 71 and the stop point or stop region of the stop element 62 are thus substantially located at the same position in longitudinal direction.

[0054] FIG. 2 shows a further design example of the prosthetic foot 1 according to the invention. The heel web 35 of FIG. 1 has been omitted here. The heel body 30 is instead configured as a separate element. The heel body 30 and the base body 60 are therefore not integrally connected to one another. The leaf spring 50 is substantially disposed in the same way as already explained for the prosthetic foot 1 of FIG. 1. According to the invention, additional mounting means can be provided in the heel body 30 to prevent a displacement of the heel body 30 in the longitudinal direction of the spring element 50. The heel body 30 of FIG. 2 also has a slot 32, in which the spring element 50 is inserted. The heel body 30 is also spring mounted such that movement in vertical direction is possible. A damper 3, which is connected to the stop 76, attaches to the upper side of the heel body 30. In one embodiment, the heel body 30 does not have any additional mounting means. The longitudinal displaceability of the heel body 30 relative to the base body 60 is limited by the damper 3 and by the stop 76.

[0055] FIG. 3 shows a prosthetic foot 1, which corresponds substantially to the prosthetic foot of FIG. 2.

[0056] One difference is that the web 65 comprises a tab 66. The tab 66 is disposed above the leaf spring 50 and extends substantially in the direction of the heel body 30 horizontally to the ground plane. In the shown design example, the tab 66 extends over approx. 40% of the distance between the web 65 and the heel body 30. If the leaf spring 50 is deformed in vertical direction, the tab 66 acts as a stop element, so that the movement of the leaf spring 50 is limited at least over the length of the tab 66. Under load, the leaf spring 50 lies flat against the tab 66.

[0057] FIG. 4 shows a cross-section through the prosthetic foot 1 of FIG. 1. Relevant planes that are necessary for specifying the position of the leaf spring 50 and the heel web 35 can be defined with the aid of this cross-section. The adapter 88, for example, with its mounting points on the base body 60, defines an adapter plane AE that extends substantially horizontally. A ground plane BE extends substantially parallel (approx. 20) to the adapter plane AE. The spring plane FE, in which the leaf spring 50 is located, extends substantially parallel to the adapter plane AE. In the shown design example, the spring plane rises toward the front by approx. 5. The heel web 35 extends along a heel web plane FE. This heel web plane FE is significantly more inclined relative to the adapter plane AE and the ground plane BE than the spring plane FE. The resulting angle is between 10 and 15.

[0058] FIGS. 5 and 6 show further perspective views of the prosthetic foot 1 of FIG. 1.

[0059] FIG. 7 shows a leaf spring 50 according to the invention, wherein said spring is subdivided into three sections; namely a front region 51, a central region 53 and a rear region 55. The front region 51 and the rear region 55 substantially occupy a quarter of the total length of the leaf spring 50. The central region extends over approx. two quarters of the total length of the leaf spring 50. The already discussed attachment by means of the screws 9 is carried out in the central region 53. The transverse webs 71, 71 abut the leaf spring 50 in the transition area from the front region 51 to the central region 53. In this region, the stop element 62 also abuts the leaf spring 50 via the damper 3.

[0060] The rear region 55 is largely occupied by the slot 52 of the heel body 30.

[0061] FIG. 8 shows a further embodiment of a prosthetic foot 1, which corresponds substantially to the prosthetic feet 1 of FIGS. 1 to 7.

[0062] In contrast to the prosthetic feet of FIGS. 1 to 3, the prosthetic foot 1 of FIG. 8 comprises a damped stop 67 in the rear region of the prosthetic foot 1. The stop 67 comprises a substantially flat lower stop region 93, which, under load, is pressed against an upper stop region 91 of a rear end stop 68. Corresponding to the upper stop region 91, the lower stop region 93 is configured such that, under load, the lower stop region 93 comes into planar contact with the upper stop region 91. This ensures a uniform introduction of force into the prosthetic foot 1.

[0063] In the unloaded state, the lower stop region 93 extends at least substantially parallel to a ground plane. When the heel body 30 is loaded, it is pressed against the rear stop 67, so that it acts as a spring and is pressed against the rear end stop 68.

[0064] The prosthetic foot 1 further comprises a web 98, via which the leaf spring 50 is supported relative to the forefoot body 70. The web 98 is bent over a web bracket 99, so that the leaf spring 50 always remains in contact with the web 98 even when the forefoot body 70 is deformed.

[0065] In the design example of FIG. 8, the stop element 62 of the base body 60 is subdivided in the front region (toward the forefoot), so that a further damping effect is provided. In the design example of FIG. 8, the stop element 62 comprises an upper stop region 94 and a lower damping region 95. The lower damping region 95 is disposed above the leaf spring 50, so that the leaf spring 50 is pressed against the lower damping region 95 when the forefoot body 70 is subjected to a load during a walking motion. The lower damping region 95 is flexible, so that the lower damping region 95 is pressed against the upper stop region 94 under load. This provides better overall damping properties, which results in greater wearing comfort for the user.

[0066] At this point, it should be noted that all of the parts described above, alone and in any combination, in particular the details shown in the drawings, are claimed as being essential to the invention. For example, numerous variations with respect to the inclination angle of the heel web 35 and/or the leaf spring 50 are conceivable. Similarly, the leaf spring 50 can be replaced by one or a plurality of leaf springs 50 and/or spring webs.

REFERENCE SIGNS

[0067] 1 Prosthetic foot [0068] 3, 3 Damper [0069] 9 Screw [0070] 30 Heel body [0071] 31 Rear sole region [0072] 32 Slot [0073] 35 Heel web [0074] 50 Leaf spring [0075] 51 Front region of the leaf spring [0076] 53 Central region of the leaf spring [0077] 55 Rear region of the leaf spring [0078] 60 Base body [0079] 61 Front sole region [0080] 62 Stop element [0081] 65 Web [0082] 66 Tab [0083] 67 Rear stop [0084] 68 Rear end stop [0085] 70 Forefoot body [0086] 71, 71 Transverse web [0087] 77 Cap [0088] 80 Mounting body [0089] 88 Adapter [0090] 91 Upper stop region [0091] 93 Lower stop region [0092] 94 Upper stop region [0093] 95 Lower damper section [0094] 96 Lower damper surface [0095] 97 Upper damper surface [0096] 98 Web [0097] 99 Web bracket [0098] AE Adapter plane [0099] FE Spring plane [0100] SE Heel web plane [0101] BE Ground plane [0102] D Gap height