Artificial Foot

• US 20080004718A1
• Filed: 06/28/2005
• Published: 01/03/2008
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: Ottobock SE & Co. KGaA
• Original Assignee: Otto Bock Healthcare Products GmbH (Albatros Son Holding BV)
• Inventors: Mosler, Lueder
• Granted Patent: US 8,246,695 B2
• Time in Patent Office: Days
• US Class Current: 623/53
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• CPC Class Codes: A61F 2/6607 Ankle joints
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/748 Valve systems
• CPC Class Codes: A61F 2002/30471 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: A61F 2002/5003 having damping means, e.g. shock absorbers
• CPC Class Codes: A61F 2002/5006 Dampers, e.g. hydraulic damper
• CPC Class Codes: A61F 2002/5038 Hinged joint, e.g. with transverse axle restricting the movement
• CPC Class Codes: A61F 2002/5041 having bearing bushes between the rotating parts
• CPC Class Codes: A61F 2002/6621 Toes
• CPC Class Codes: A61F 2002/6635 Metatarsals
• CPC Class Codes: A61F 2002/6642 Heels
• CPC Class Codes: A61F 2002/7615 Measuring means
• CPC Class Codes: A61F 2220/0091 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type

Abstract

The invention relates to an artificial foot having a connecting part (3, 3′) for a lower leg part (5), and a base foot part (1, 1′) rotatably connected to the connecting part (3, 3′) via an ankle joint (2). Said base foot part extends rearwards of the ankle joint (2) in a heel section (8) and forwards of the ankle joint (2) in a midfoot section (11, 11′). A forefoot part (12, 12′) is rotatably connected to the midfoot section (11, 11′). In order to allow an automatic adaptation of the foot to varying heel heights while ensuring a good stability, an articulated connection transmits the angular position of the connecting part (3, 3′) in relation to the base foot part (1, 1′) in a proportional manner to the angular position of the forefoot part (12, 12′) in relation to the base foot part (1, 1′).

Claims

1. An artificial foot with a connecting part (3, 3′

) for a lower leg part (5), with a base foot part (1, 1′

) which is pivotably connected to the connecting part (3, 3′

) via an ankle joint (2) and which extends rearward of the ankle joint (2) into a heel section (8) and forward of the ankle joint (2) into a midfoot section (11, 11′

), and with a forefoot part (12, 12′

) pivotably connected to the midfoot section (11, ii′

), characterized by an articulated connection that transmits the angular position of the connecting part (3, 3′

) relative to the base foot part (1, 1′

) in a proportional manner to the angular position of the forefoot part (12, 12′

) relative to the base foot part (1, 1′

).

2. The artificial foot as claimed in claim 1, characterized in that the articulated connection is designed as a four-joint arrangement.

3. The artificial foot as claimed in claim 1, characterized in that the articulated connection is formed by the midfoot section (11, 11′

) and by a linking rod (16, 16′

, 16″

) that is connected in an articulated manner to forefoot part (12, 12′

) and connecting part (3, 3′

).

4. The artificial foot as claimed in claim 3, characterized in that the midfoot section (11, 11′

) and the linking rod (16, 16′

16″

) are arranged substantially parallel to one another.

5. The artificial foot as claimed in claim 1, characterized in that the connecting part (3, 3′

) has an extension piece (17, 17′

) which extends downward across the ankle joint (2) and on which the linking rod (16, 16′

, 16″

) is secured pivotably via one of its ends.

6. The artificial foot as claimed in claim 1, characterized in that at least one hinged connection is formed by a flexible section (13′

) of a coupling piece of the articulated connection.

7. The artificial foot as claimed in claim 1, characterized by an adjustment element (22) which is arranged between base foot part (1) and connecting part (3) and whose adjusting action comes into effect only when there is a load that continues over several seconds.

8. The artificial foot as claimed in claim 7, characterized in that the adjustment element (22) is formed by a hydraulic cylinder.

9. The artificial foot as claimed in claim 8, characterized in that a valve arrangement (26) is inserted into a circuit line (25) in which hydraulic fluid flows from one side to the other side of a piston (24) of the hydraulic cylinder (22), which valve arrangement (26) blocks the circuit line (25) when a predetermined flow velocity is exceeded.

10. The artificial foot as claimed in claim 7, characterized in that the adjustment element (22) is combined with an elastic member that can be deformed by momentary loads.

11. The artificial foot as claimed in claim 1, characterized in that at least one coupling piece (16′

) of the articulated arrangement is designed to be elastically deformable in the longitudinal direction.

12. The artificial foot as claimed in claim 11, characterized in that the coupling piece (16′

) in the articulated arrangement is subjected mainly to tensile loading.

13. The artificial foot as claimed in claim 1, characterized in that at least one coupling piece (16″

) of the articulated arrangement is designed to be adjustable in length.

14. The artificial foot as claimed in claim 13, characterized in that the length adjustment of a length-adjustable coupling piece (16′

) can be controlled by at least one sensor that detects parameters of the walking or standing situation.

15. The artificial foot as claimed in claim 13, characterized in that the length adjustment is performed by a hydraulic cylinder.

16. The artificial foot as claimed in claim 1, characterized by an elastic member (31) between forefoot part (12) and base foot part (1, 1′

).

17. The artificial foot as claimed in claim 16, characterized by a spring/damper combination between forefoot part (12) and base foot part (1, 1′

).

18. The artificial foot as claimed in claim 1, characterized in that the spacing between the joints (13, 13′

, 15) on the forefoot part (12, 12′

) is smaller than the spacing between the joints (2, 18) on the connecting part (3, 3′

).

19. The artificial foot as claimed in claim 5, characterized in that the extension piece (17, 17′

) of the connecting part (3, 3′

) is mounted elastically on the connecting part (3, 3′

).

20. The artificial foot as claimed in claim 1, characterized in that the ankle joint (2) is arranged at a distance forward of a connection point between the connecting part (3, 3′

) and the lower leg part (5).

21. The artificial foot as claimed in claim 1, characterized in that, starting from a sole area (14), the heel section (8) of the base foot part (1) is designed ascending toward the connecting part (3), comprises an approximately rectilinear midfoot section (11), and is connected to the ankle joint (2) centrally in relation to its axial length.