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Publication numberUS3890650 A
Publication typeGrant
Publication dateJun 24, 1975
Filing dateAug 2, 1974
Priority dateAug 18, 1973
Also published asDE2341887A1, DE2341887B2, DE2341887C3
Publication numberUS 3890650 A, US 3890650A, US-A-3890650, US3890650 A, US3890650A
InventorsPrahl Jan
Original AssigneeIpos Gmbh & Co Kg
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Artificial foot for leg prostheses
US 3890650 A
Abstract
An artificial foot made of synthetic materials with an integrally cast metallic base plate having a forward downwardly depending offset portion of a unique configuration, the rear end of the base plate being supported by a tab.
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Description  (OCR text may contain errors)

United States Patent Prahl June 24, 1975 [54] ARTIFICIAL FOOT FOR LEG PROSTHESES 1,219,374 3/1917 Carrico 3/7 5] Inventor: Jan rah uneburg, Germ y 3,484,871 12/1969 Orange 3/7 [73] Assignee: Ipos Gesellschalt fur Integrierte FOREIGN PATENTS OR APPLICATIONS Proihesenemwicklung 137,843 7 1959 U.S.S.R 3/6 Orthopadietechnischen Service m.b.H. & Co. K.G., Germany Primary Examiner-Ronald L. Frinks [22] Flled' 1974 Attorney, Agent, or Firm-Toren, McGeady and [211 Appl. No.: 494,277 Stanger {30] Foreign Application Priority Data Aug. 18, 1973 Germany 2341887 71571 ABSTRACT [52] U 8 Cl 3/7 An artificial foot made of synthetic materials with an [51] I08 integrally cast metallic base plate having a forward downwardly depending offset portion of a unique com [58] Field of Search 3/6-8, 2 figuration the rear end of the base plate being p [56] References Cited ported by a 464 356 ZIST PATENTS 3/7 X 4 Claims, 1 Drawing Figure ARTIFICIAL FOOT FOR LEG PROSTHESES The present invention relates to an artificial foot made of foamed synthetic materials that are foamed within a mold, for leg prostheses.

In the operational behaviour of a leg prothesis, the foot and the functional characteristics of the same are of considerable importance. The foot must allow the amputated patient to tread on the ground with a maximum of dampening. in simultaneously providing a rigid linkage for the prothesis and maintaining, during walking, the highest possible degree of resiliency of the rolling motion resistance.

For quite some time have been known artificial feet made of felt and rubber, with a wooden reinforcement. In the course of development, artificial feet of this type have been replaced by artificial feet made of resilient plastic or synthetic materials. The preferred materials employed have been foamed polyurethanes that were advantageous because of their low weight. The foot functions were provided by adhesively bonding several foamed materials of different hardness. The connecting element for connecting the foot with the prosthetic leg member was as before manufactured of wood. There has also been proposed to provide aluminium plates as connecting members for attachment to the highly resiiient foam at the sole of the foot. These proposals, however, encountered difficulties since the prior art aluminium plates were not adapted properly to the foot function.

Heretofore known artificial feet were unsatisfactory because of the insufficient aging resistance of adhesively bonded foam materials, the humidity absorption properties ofthe wooden core and the unfavorable rolloff motion function of the molded-in aluminium plates whereby this function was delimited in a central region of the foot.

It is now the object of the present invention to provide an artificial foot for leg prostheses in which the above pointed out drawbacks are eliminated and the full operational functions of the foot are providedv For achieving this object, there is now proposed, in accordance with the present invention, an artificial foot made of foamed synthetic materials that are foamed within a mold, for leg prostheses, and this artificial foot is characterized by a metallic base plate disposed in the area of the sole of the foot within the foamed foot member, a forwardly extending portion of the metallic base plate defining a downwardly depending offset portion, the configuration of the offset portion of the base plate adapted to the roll-off motion of the ball of the foot, the offset portion secured to a forefoot core made of a homogeneous plastic material, the configuration of the forefoot core corresponding to the shape of the point of the foot, and a rearwardly extending portion of the metallic base plate supported by a portion of a tab made of a homogeneous plastic material, the tab being disposed within the heel portion of the foot.

According to another characteristic of the present invention, a recess is provided in a rearward portion of the foot and extends from the top surface of the artificial foot down to the upper surface of the metallic base plate and adapted to receive articulation and attachment members.

The drawing illustrates a longitudinal vertical sectional view of an artificial foot in accordance with a preferred embodiment of the present invention.

A metallic base plate 10 is provided in the area of the sole of the foot. The metallic base plate 10 is adapted to the configuration of the sole of the foot within the area of the ball of the foot 12 by means of a downwardly depending offset portion 11. The offset portion 11 allows to perform the rolling motion functions of the foot within a transverse sectional area located substantially in a region intermediate a first and a second third at the forward end of the foot when assuming the foot to be subdivided, along its length, into three longitudinal portions of approximately equal lengths. This transverse area is predetermined by nature itself and substantially coincides with the line of articulation of the toes. To adapt the rolling motion resistance of the artificial foot to the natural foot function, a forefoot core 14 made of a homogeneous elastomer material is prevulcanized to the downwardly depending offset portion 11 of the base plate 10. The lower boundary of the forefoot core 14 corresponds to the outer configuration of the ball of the foot. This forefoot core 14 is of a nonfoamed structure and is perfectly resistant to aging. Therefore the rolling motion resistance may be predetermined and will not alter during extended periods of time. Within the heel portion of the artificial foot, a tab is likewise made of a homogeneous elastomer material is prevulcanized to the metallic base plate 10 and forms a reinforcement member. The thus formed functional core of the foot comprising the metallic base plate 10, the forefoot core 14 and the tab 15 may be readily adapted to any size of foot and to different heel heights.

The actual foot body 16 is integrally foamed of a cellular material about the functional foot core, in order to preserve a low weight of the foot. A recess 17 may be provided within a rearward portion of the artificial foot. This recess 17 may extend from the top surface of the foot body down to the upper surface of the metallic base plate 10 and allows to threadedly attach articulation and attachment members directly to the metallic base plate 10.

What is claimed is:

1. An artificial foot made of foamed synthetic materials that are foamed within a mold, for leg prostheses, characterized by a metallic base plate disposed in the area of the sole of the foot within the foamed foot member, a forwardly extending portion of said metallic base plate defining a downwardly depending offset portion, the configuration of said offset portion of said base plate adapted to the roll-off motion of the ball of the foot, said offset portion secured to a forefoot core made of a homogeneous plastic material, the configuration of said forefoot core corresponding to the shape of the point of the foot, and a rearwardly extending portion of said metallic base plate supported by a portion of a tab made of a homogeneous plastic material, said tab being disposed within the heel portion of the foot.

2. An artificial foot as in claim I, further characterized by a recess in a rearward portion of the foot, said recess extending from the top surface of said artificial foot down to the upper surface of the metallic base plate and adapted to receive articulation and attachment members.

3. An artificial foot as in claim 2, further characterized in that said forefoot core and said tab are made of a homogeneous elastomer material.

4. An artificial foot as in claim 3, further characterized in that the foot body is integrally foamed ofa cellular resilient material about the functional core of the foot consisting of said metallic base plate, said forefoot core and said tab.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US464356 *Apr 1, 1891Dec 1, 1891 Artificial limb
US1219374 *Oct 25, 1916Mar 13, 1917Walter CarricoArtificial foot.
US3484871 *Dec 2, 1968Dec 23, 1969Orange John LArtificial foot
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4089072 *Jul 13, 1976May 16, 1978Otto Bock Orthopadische Industrie K.G.Prosthetic appliance
US4177525 *Nov 9, 1977Dec 11, 1979Ohio Willow Wood Co., Inc.Reinforced artificial foot and method of making
US4225982 *Dec 4, 1978Oct 7, 1980Cochrane Ian WMolded syme foot with attached stump socket
US4645509 *Jun 11, 1984Feb 24, 1987Model & Instrument Development CorporationProsthetic foot having a cantilever spring keel
US4892553 *Jun 10, 1988Jan 9, 1990Ipos Gmbh & Co, KgArtificial foot for a leg prosthesis
US5007938 *Aug 15, 1989Apr 16, 1991Ipos Gmbh & Co. KgArtificial foot for a leg prosthesis
US5037444 *Jan 5, 1989Aug 6, 1991Phillips L VanProsthetic foot
US5066305 *Oct 25, 1988Nov 19, 1991Model & Instrument Development CorporationProsthetic foot having a low profile cantilever spring keel
US5181932 *Apr 13, 1989Jan 26, 1993Phillips L VanFoot prosthesis having auxiliary ankle construction
US5458656 *Dec 20, 1993Oct 17, 1995Flex-FootEnergy-storing prosthesis leg pylon vertical shock leg
US5486209 *Jul 1, 1994Jan 23, 1996Phillips; Van L.Foot prosthesis having auxiliary ankle construction
US5509938 *Jan 4, 1994Apr 23, 1996Phillips; Van L.Prosthetic foot incorporating adjustable bladder
US5514185 *Jan 21, 1994May 7, 1996Phillips; Van L.Split foot prosthesis
US5549714 *Jan 12, 1995Aug 27, 1996Phillips; Van L.Symes foot prosthesis
US5593457 *Sep 22, 1995Jan 14, 1997Phillips; Van L.Foot prosthesis having auxiliary ankle construction
US5976191 *Oct 8, 1996Nov 2, 1999Phillips; Van L.Foot prosthesis having curved forefoot
US6406500Nov 2, 1999Jun 18, 2002Van L. PhillipsFoot prosthesis having curved forefoot
US6443995Dec 22, 2000Sep 3, 2002Barry W. TownsendProsthetic foot
US6743260Jul 31, 2001Jun 1, 2004Barry W. TownsendProsthetic foot
US6936074Mar 2, 2004Aug 30, 2005Barry W. TownsendProsthetic foot
US7108723Jun 10, 2004Sep 19, 2006Townsend Barry WProsthetic foot
US7503937Jun 29, 2007Mar 17, 2009Ossur HfProsthetic foot
US7771488Oct 1, 2008Aug 10, 2010Ossur HfProsthetic foot
US8177855Oct 1, 2008May 15, 2012Ossur HfProsthetic foot
US8317877Aug 18, 2008Nov 27, 2012The Ohio Willow Wood CompanyProsthetic foot
US9351853Dec 1, 2014May 31, 2016The Ohio Willow Wood CompanyProsthetic foot
US20020087216 *Feb 25, 2002Jul 4, 2002Atkinson Stewart L.Prosthetic walking system
US20040199265 *Mar 2, 2004Oct 7, 2004Townsend Barry W.Prosthetic foot
US20040225376 *Jun 10, 2004Nov 11, 2004Townsend Barry W.Prosthetic foot
US20080004719 *Jun 29, 2007Jan 3, 2008Sigurdur AsgeirssonProsthetic foot
US20090030531 *Oct 1, 2008Jan 29, 2009Sigurdur AsgeirssonProsthetic foot
US20090043403 *Oct 1, 2008Feb 12, 2009Sigurdur AsgeirssonProsthetic foot
US20100042228 *Aug 18, 2008Feb 18, 2010The Ohio Willow Wood CompanyProsthetic foot
WO2007071993A2 *Dec 19, 2006Jun 28, 2007Robert John WattsFoot prosthesis
WO2007071993A3 *Dec 19, 2006Aug 23, 2007Robert John WattsFoot prosthesis
Classifications
U.S. Classification623/55
International ClassificationA61F2/66, A61F2/50, A61F2/60
Cooperative ClassificationA61F2002/5007, A61F2002/6657, A61F2/66
European ClassificationA61F2/66