DE102011053765A1 - Foot spring assembly for foot prosthesis for connecting foot portion with artificial lower leg, has support body set between spring elements and on sub region on sides of spring layer and limiting compression of thickness of spring layer - Google Patents

Abstract

The assembly (1) has leaf spring elements (4) connected with each other by moment-rigid connection parts (51, 52). Distance of the spring elements in a region between connection parts is changed by clamping and releasing the spring elements that are separated from each other by an elastically resilient spring layer (6). A spacing support body (7) is arranged between the spring elements and on a sub region on sides of the spring layer, and limits compression of the spring layer with approximately 50 percent of thickness, where the spring layer flexibly surrounds the body. The leaf spring element is formed from steel, a carbon composite material or titanium. The spring layer is formed by a high elastic foam material. The spacing support body is formed from hard rubber. An independent claim is also included for a foot prosthesis.

Description

The invention relates to a Fußfederanordnung for a prosthetic foot, which connects a foot part with an artificial lower leg or leg extension or forms this in areas and a prosthetic foot with such a Fußfederanordnung.

Foot prostheses have the goal to provide the most natural movement and comfortable walking available. Very often, the arrangements are too rigid or too complex, so that an intuitive walking a person with a prosthetic foot is not possible.

From the US 5,166,384 a spring arrangement is known in which between two spaced apart with a clearance spacing leaf spring elements, a buffer memory is arranged, which is able to absorb a partial charge of the energy to be absorbed. However, this arrangement is complicated and expensive to manufacture because of the parts used.

From the US 5,181,933 is a foot known, in which a slit in a foot plate arranged in parallel and on one side moments rigidly hinged spring elements for comfortable walking suggests. A similar arrangement beats the US 5,443,528 in front. Here, however, more than two spring elements are connected in parallel, which are held on one side torque.

Also from the DE 93 15 665 U1 is a C-shaped heel spring of a plurality of parallel with a clearance spaced from each other, at its ends torque-locked connected leaf spring elements known, which allows an energy absorption when they occur.

A parallel connection of two-sided momentarily arranged leaf spring elements of a Fußfederanordnung is from the US 5,549,711 known. In this case, a plurality of leaf spring elements are formed together with a clearance between them at the ends, on the one hand to form a Vorderfußfeder, on the other hand to form a separate heel spring.

The US 5,725,598 shows a Fußfederanordnung, which partially replaces the lower leg, in which two parallel-connected C-shaped leaf spring elements are summarized on both sides torque-solid with a connecting element, wherein a spacer, the leaf spring elements are spaced from each other. However, the arrangement shown here is very rigid and designed with little energy storage, so that a typical prosthesis-carrier-moving image will adjust because of the little to no resilient foot part.

From the EP 1372547 A is known a Fußfederanordnung that connects a foot with an artificial lower leg or leg extension or forms this in areas. In this case, the Fußfederanordnung several parallel and parallel arranged elongated leaf spring elements. At the ends of the leaf spring elements are connected by a mechanical connection torque rigid. A disadvantage of this arrangement is that when clamping and relaxing the Fußfederanordnung the distance between the leaf spring elements in the area between the torque rigid connections changed so that in an extreme case, the leaf spring elements touch and it can come to an abrupt expansion stop of the leaf spring package, which is one for the Runner represents unpleasant limit point. This spring is already very close to the replica of a natural movement. However, hardly any adaptation to fine votes is possible.

The object of the invention is to provide a Fußfederanordnung available, which allows an adaptation to the carrier and avoids the hard stops of the described prior art under extreme load on the stop.

This object is achieved by a Fußfederanordnung for a prosthetic foot according to the features of claim 1 and a prosthetic foot according to the features of claim 6.

According to a first aspect of the invention, a foot spring assembly for a foot prosthesis, which connects a foot part with an artificial lower leg or leg extension or forms this in areas, wherein the Fußfederanordnung comprises a plurality of parallel and parallel arranged elongated leaf spring elements, wherein the leaf spring elements to a Toward the end have a stronger curvature than at the opposite end, wherein the leaf spring elements are connected at their ends by means of a mechanical by the leaf spring elements cross-connection momentarily rigid, wherein by clamping and relaxing the Fußfederanordnung the distance of the leaf spring elements changed in the range between the torque-rigid connections , Which is characterized in that the leaf spring elements are separated from each other by a respective resilient spring layer, wherein between the leaf spring elements and on a Teilberei On at least one side of the elastically yielding spring layer, a spacer body is arranged, which limits the compression of the resilient spring layer surrounding the spacer body to approximately 50% of its layer thickness.

The foam filling allows a flexibility control on the Fußfederanordnung. The known multilayer structure of leaf spring elements is improved by introducing foam layers and a spacer to maintain a minimum distance between each layer in the following functions.

The introduced foam layers, the incoming forces are absorbed much better in the heel contact moment and affect the plantar response of the footplate significantly more comfortable for the patient, so that the footplate does not noticeably hits the floor, but a smooth flow occurs.

The introduction of dirt particles at spaced parallel leaf spring elements is almost 100% excluded, thus significantly improving the durability of the foot. In unfavorable pollution (split, sand, ...), this may even lead to failure of the spring function in the state he technology.

The activity and body weight of the patient can be considered more precisely, since the volume weight of the foam influences the compression speed of the leaf spring elements formed, for example, as graphite carbon plates, in the form that the charge acceptor and the charge releasing moment can be provided with more or less resistance ,

The glued in the minimum distance holding spacer body allow in the compression phase, a charge limit which also serves the conservation of the material and to prevent the breakdown of the individual layers. The adhesion of the foam acts against the displacement and fixes the foam layers in the movement.

Advantageously, the leaf spring elements made of steel, a carbon composite, titanium, or a mixture of these are made.

Preferably, the spring layer is formed by a highly elastic foam.

An advantageous development of the invention provides that the spacer body is made of a hard rubber.

According to the second aspect of the invention, a prosthetic foot is provided, which has a Fußfederanordnung according to one of claims 1 to 4.

Advantageously, the prosthetic foot at the upper, the lower leg or leg extension facing the end of the leaf spring elements which form the Fußfederanordnung an adapter piece.

Preferably, it is provided according to a development of the invention that the deflection of the Fußfederanordnung is limited relative to the foot by an investment wedge.

The foot part advantageously also has a parallel spring arrangement in its front region and / or the heel region, in particular by means of an incision into the material of the foot part.

Further advantageous embodiments will become apparent from the other dependent claims or their possible sub-combinations.

The invention will be further explained with reference to the drawings. In detail, the schematic representation in:

1 a schematic representation of a prosthetic foot according to the invention with a Fußfederanordnung invention,

2 a schematic representation of a Fußfederanordnung invention,

3 a schematic representation of the Fußfederanordnung 2 in pieces,

4 a schematic detail view of a not yet inserted in a partial recess of the spring layer spacer body,

5 the spring layer off 4 with already inserted spacer body seen from the other side,

6 a schematic sectional view corresponding to the line VI 4 .

7 a schematic sectional view corresponding to the line VII 4 .

8th a schematic sectional view corresponding to the line VIII 5 .

9 a schematic sectional view through the parallel arrangement of the leaf spring elements of the invention Fußfederanordnung in a relaxed position, and

10 a corresponding sectional view through the same parallel arrangement of the leaf spring elements accordingly 9 , wherein the leaf spring elements are maximally deflected against each other and prevent the spacer body a further approach to not compress the spring layer.

The same reference numerals in the figures designate the same or equivalent elements.

In 1 is an exemplary Fußfederanordnung 1 in a prosthetic foot 2 shown. This is a footboard 3 to connect with an artificial lower leg or leg extension via an adapter piece. In areas the spring above the position of the former ankle forms the lower leg.

The foot spring arrangement 1 consists of several parallel and parallel arranged elongated leaf spring elements 4 , The leaf spring elements 4 point to the bottom 41 towards a stronger curvature than at the opposite end 42 on.

In summary, the leaf spring elements 4 at their ends 41 . 42 each momentary solid by means of a mechanical through the leaf spring elements 4 gripping connection 51 . 52 in the form of a screw.

Too large a deflection of the Fußfederanordnung 1 opposite the foot part 3 Preventing is an investment wedge 9 intended.

The foot part 3 points to further running comfort in the example in its front area 31 a parallel spring arrangement 33 on. This is achieved through an incision 34 into the material of the foot part.

In 2 and the following figures is the foot spring assembly 1 shown in more detail.

The leaf spring elements 4 are separated from each other by an elastically resilient spring layer 6 separated.

See also the schematic decomposition after 3 , The leaf spring elements are in the region of the connection by the screw by incompressible elements 43 for the expansion of the spring layer 6 spaced. The forming distance is completely through the spring layer 6 ingested.

Between the leaf spring elements 4 and on a portion on one side of the resilient spring layer 6 are spacer bodies 7 arranged the compression of the spacer body 7 surrounding resilient spring layer 6 limit to about 50% of their layer thickness. As a result, an overuse of the foam layers is prevented.

In 4 is a schematic detail view of a not yet in a partial recess 61 the spring layer 6 inserted spacer body 7 shown. In 5 is the spacer body 7 already inserted.

The 6 . 7 and 8th show schematic sectional view corresponding to the lines VI and VII 4 , as well as line VIII 5 ,

By tensioning and relaxing the Fußfederanordnung 1 the distance between the leaf spring elements changes 4 in the range between the torque-fast connections 51 . 52 ,

This is in the 9 and 10 shown in more detail. So shows 9 in a schematic sectional view through the parallel arrangement of the layer sequence of leaf spring elements 4 and the spring layers 6 the foot spring assembly according to the invention 1 in a relaxed position the relaxed state of the spring layers and in 10 a corresponding sectional view through the same parallel arrangement of the leaf spring elements, wherein the leaf spring elements are maximally deflected against each other and the spacer body prevent further approximation under compression of the spring layers.

The leaf spring elements 4 may be made in the context of the invention of steel, a carbon composite, titanium, or a mixture of these.

The spring layer 6 can be formed by a highly elastic foam. Depending on the body weight of the wearer of the prosthesis, the elasticity can be adjusted. An adaptation for sensitive users is also possible later.

Accordingly, the spacer body 7 To prevent a hard end stop from being made of a hard rubber.

LIST OF REFERENCE NUMBERS

1

Fußfederanordnung

2

Foot prosthesis

3

footboard

31

front area

32

heel

33

spring assembly

34

incision

4

Leaf spring element

41, 42

End of the leaf spring element

43

spacer

44, 45

drilling

51, 52

connection

6

spring layer

61

Partial recess in the layer

7

Spacer body

8th

adapter piece

9

conditioning wedge

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5166384 [0003]
• US 5181933 [0004]
• US 5443528 [0004]
• DE 9315665 U1 [0005]
• US 5549711 [0006]
• US 5725598 [0007]
• EP 1372547 A [0008]

Claims (8)

Foot spring arrangement ( 1 ) for a prosthetic foot ( 2 ), which has a foot part ( 3 ) connects to or forms an artificial lower leg or leg extension, wherein the foot spring arrangement ( 1 ) a plurality of parallel and parallel arranged elongated leaf spring elements ( 4 ), wherein the leaf spring elements ( 4 ) to an end ( 41 ) a stronger curvature than at the opposite end ( 42 ), wherein the leaf spring elements ( 4 ) at their ends ( 41 . 42 ) each by means of a mechanical through the leaf spring elements ( 4 ) cross-linking ( 51 . 52 ) are rigidly connected to each other, wherein by tensioning and relaxing the spring assembly ( 1 ) the distance of the leaf spring elements ( 4 ) in the area between the torque-stable connections ( 51 . 52 ), characterized in that the leaf spring elements ( 4 ) from each other by a respective resilient spring layer ( 6 ) are separated, wherein between the leaf spring elements ( 4 ) and on a portion on at least one side of the resilient layer ( 6 ) a spacer body ( 7 ) is arranged, the compression of the spacer body ( 7 ) surrounding resilient spring layer ( 6 ) is limited to approx. 50% of its layer thickness. Foot spring arrangement for a prosthetic foot according to claim 1, characterized in that the leaf spring elements ( 4 ) made of steel, a carbon composite, titanium, or a mixture of these. Foot spring arrangement for a prosthetic foot according to claim 1 or 2, characterized in that the spring layer ( 6 ) is formed by a highly elastic foam. Foot spring arrangement for a prosthetic foot according to one of claims 1 to 3, characterized in that the spacer body ( 7 ) is made of a hard rubber. Prosthetic foot ( 2 ), characterized in that this one Fußfederanordnung ( 1 ) according to one of claims 1 to 4. Prosthetic foot according to claim 5, characterized in that at the top ( 41 ), the lower leg or leg extension facing the leaf spring elements ( 4 ) which the Fußfederanordnung ( 1 ) form an adapter piece ( 8th ) is provided. Prosthetic foot according to claim 5 or 6, characterized in that the deflection of the Fußfederanordnung ( 1 ) opposite the foot part ( 3 ) by an investment wedge ( 9 ) is limited. Prosthetic foot according to one of claims 5 to 7, characterized in that the foot part ( 3 ) in its front area ( 31 ) and / or the heel area ( 32 ) also a parallel spring arrangement ( 33 ), in particular by an incision ( 34 ) into the material of the foot part ( 3 ), having.

Images