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Publication numberUS3520002 A
Publication typeGrant
Publication dateJul 14, 1970
Filing dateNov 29, 1967
Priority dateNov 29, 1967
Publication numberUS 3520002 A, US 3520002A, US-A-3520002, US3520002 A, US3520002A
InventorsCharles L Wellington
Original AssigneeCharles L Wellington
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Artificial limb with an expansible foam stump socket
US 3520002 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

July 14, 1910 c. L. WELLINGTON ARTIFICIAL LIMB WITH AN EXPANSIBLE FOAM STUMP SOCKET Filed Nov. 29, 1967 JNVENTOR CHARLES L. WELLINGTON 6 Y- Q i ZTTORNEfiS United States Patent 3,520,002 ARTIFICIAL LIMB WITH AN EXPANSIBLE FOAM STUMP SOCKET Charles L. Wellington, 1228 Orion St., Metairie, La. 70005 Filed Nov. 29, 1967, Ser. No. 686,502 Int. Cl. A61f 1/02 US. Cl. 319 2 Claims ABSTRACT OF THE DISCLOSURE An artificial limb having a rigid outer shell defining a cavity for receiving a limb stump. A stump socket is carried in the cavity and includes flexible pads positioned adjacent the inner wall of the outer shell of the artificial limb. An expansible foam material is inserted in the cavity in a liquid state, and is capable of expanding into a substantially rigid cellular supporting foam structure. An elastomeric member is positioned on the patients limb stump in a stretched state for emphasizing scar tissue and bony areas of the limb. The limb stump is inserted within the socket prior to the expandible polymer expanding so that when such expands a rigid cellular supporting structure is produced having a cavity with an inner wall complementary in shape to the limb stump.

This invention relates to artificial limbs, and more particularly to a supporting stump socket for the artificial limb.

Heretofore, stump sockets for artificial limbs have been constructed of various materials. Canvas and stitched leather sockets were used for many years. However, such were not satisfactory since they often caused chafing and were not always comfortable due to the difficulty in properly fitting the socket for a particular patients use. Attempts have been made to produce limb sockets which were complementary in shape to the patients limb stump by first making a plaster of Paris stump which corresponded to the limb stump. A flexible socket was usually made using such a plaster mold in order to produce a closely fitting and comfortable socket. One such method similar to this is disclosed in the Ryan Pat. No. 2,578,019 granted on Dec. 11, 1951. One of the problems encountered in first making a plaster of Paris mold is that the limb stump normally changes shape when mounted in an artificial leg due to the pressure exerted thereon, thus resulting in a poorly fitting and uncomfortable artificial limb.

Limb stumps constructed in accordance with the present invention minimizes the above-mentioned problems, since in forming the stump socket an elastomeric member is placed on the limb stump in a stretched state so as to emphasize scar tissue and bony areas on the stump which are normally the most sensitive areas thereon.

Accordingly, it is an important object of this invention to provide an artificial leg having a stump socket which minimizes the above-mentioned problems.

Another important object of the present invention is to provide a stump socket for an artificial leg which is closely fitting and comfortable for the patient.

Still another important object of the present invention is to provide an artificial limb with a stump socket which is easy and quick to construct, while conforming to the exact shape of the limb stump.

Still another important object of the present invention is to provide a stump socket which distributes pressure on the stump of the patient in a manner which minimizes chafing and soreness.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof.

3,520,002 Patented July 14, 1970 The invention will be more readily understood from a reading of the following specification, and by reference to the accompanying drawing forming a part thereof, wherein an example of the invention is shown and wherein:

FIG. 1 is an elevational view, partially in section, of an artificial leg showing the stump socket.

FIG. 2 is an elevational view, partially in section, of an artificial leg constructed in accordance with the present invention having a modified base portion, and

FIG. 3 is an elevational view illustrating the manner in which the limb stump is prepared prior to making the socket for the artificial leg.

The drawing illustrates an artificial limb having a rigid outer shell A which defines a cavity for receiving a limb stump B. A stump socket is carried in the cavity A and includes flexible pads C positioned adjacent the inner wall of the outer shell of the artificial limb. An expansible polymer is inserted in the cavity in a liquid state, and is capable of expanding into a substantially rigid cellular supporting foam structure D. A form generally having an external shape corresponding to the shape of the limb stump B is positioned in the cavity prior to the polymer expanding. Thus, as the polymer expands a substantially rigid cellular supporting structure is produced having a cavity with an inner wall complementary in shape to the form for providing a closely fitting comfortable stump socket. The rigid cellular supporting structure is reinforced by the flexible pads C.

One of the most difiicult problems associated with an artificial leg is acquiring a good comfortable fit between the limb stump and the socket which receives such. Heretofore, as previously mentioned, plaster of Paris casts were used in forming the stump socket and pads were used to make such fit properly. The disadvantage to this method is that it is impossible to judge exactly what size padding, and where such should be applied.

The outer shell A of the artificial leg may be constructed from any suitable material, such as metal, extruded plastic, etc., and has a foot portion 10 hinged to the bottom thereof in any suitable conventional manner. The outer shell A defines a cavity, the lower end of which is closed by any suitable means. In FIG. 1 the lower end of the cavity is shown as being closed with a wooden base 11, while in FIG. 2 the lower end of the cavity is filled with a hard solid material 12, such as polyester resin, or any suitable light plastic substance. Another layer of light hard plastic material 13 is positioned on top of the solid material 12 and extends upwardly in the cavity to a point approximately 2 to 3" below where the bottom portion of the limb stump would normally extend Within the cavity. After the lower end of the cavity is closed the artifiical leg is ready to be equipped with the stump socket.

First, flexible pads C which may be constructed of any suitable material, such as flexible polyurethane, are positioned on the inner wall of the outer shell A. These pads may be of any suitable shape, however, they are shown in FIGS. 1 and 2 as being ring-shape pads adhered by any suitable means to the outer shell A. The patient for whom the artificial limb is being prepared then places a very light stump sock /z ply) on his limb stump B. An elastomeric sleeve member 15 is pulled over the stump sock 14 in a stretched state so as to emphasize the contour of the limb stump. Such an elastomeric member may be a latex rubber sleeve with one end closed. By stretching the elastomeric member over the limb stump such causes the limb stump to assume a contour which corresponds to the contour of the limb stump when such is positioned under pressure in the artificial leg.

Thus, the rubber or elastomeric sleeve 15 must be quite tight so as -to serve the purpose of forming the stump into the shape that it assumes in the prothesis under pressure.

The next step in the process of making the limb socket is the preparation and application of the rigidcellular foam structure D. One suitable cellular foam used is manufactured by Cooke Paint & Varnish Company of Kansas City, Mo., and is referred to as C Foam System #460. This polyurethane foam can be mixed in small quantities in a fluid state. After the polyurethane foam has been mixed such is placed on top of the base enclosures 11 or 13. The patient then inserts the stump within the socket and remains erect for approximately fifteen to twenty minutes in order to get the proper angle between the stump and the casing A to assure proper positioning for walking. For the convenience of the patient not having experience with this process, it is sometimes necessary to form a jig which will allow the patient to remain seated and still give the proper angle. When a new limb is being made, the stump B can be positioned centrally within the cavity, and any variations needed can be achieved with alignment screws.

The stump is left in the artificial leg until the foam has risen to encompass the limb stump and set enough so that the elastomeric member 15 begins to free itself from the form, usually fifteen to twenty minutes. The stump is then removed from the elastomeric member 15 leaving such inside the stump socket temporarily. The prothesis is allowed to set overnight at a temperature of approximately 80 Fahrenheit. After the prothesis has set, the elastomeric member is then removed and the cavity formed in the stump stocket is the complement of the patients limb stump B and provides a closely fitting and comfortable stump socket. During forming of the cellular socket a polyethylene sheet is wrapped around the outer shell A for preventing the foam from overflowing onto the outer shell A.

The flexible foam pads C strengthens the rigid foam and provides a sturdy and durable stump socket. Sometimes, in order to protect the scar and bony areas it is necessary to hollow out the foam adjacent these areas a small amount during the fitting stage. One particular advantage of using the foam is that if the limb stump changes shape a new stump socket can be made without discarding the entire artificial limb. The stump socket constructed in accordance with the present invention requires no liners or inserts in order to properly fit the limb stump therein. It is noted that the rear portion 16 adjacent the top of the outer shell A is flared outwardly so as to permit the patient to bend his leg at the knee joint freely. After the artificial limb has been fitted to the patient and any modifications completed, a light coat or two of polyester resin or other suitable wearable plastic coating is placed over the upper three or four inches of the foam in order to give such a hard smooth surface for better wear. Some of the advantages of using polyurethane cellular foam is that it is non-toxic, odorless, has sufiicient strength and hardness for support,

can be easily removed and new foam put in the same place if necessary due to changes in the stumps shape, allows passage of air, absorbs small amounts of moisture from perspiration, is resistant to normal acids, is selfextinguishing in regard to fire, and is lightweight.

In one particular artificial leg the flexible polyurethane foam pads are approximately /8" in thickness. During the foaming operation of the cellular structure D heat will be generated, however, if the polyurethane is prepared properly, such is not uncomfortable during the fitting operation.

The stump socket constructed in accordance with the present invention eliminates the time-consuming step of first producing a plaster of Paris mold which frequently is not the same shape of the limb stump when such is under pressure. The artificial limb may be attached to the patients thigh by any suitable attachment.

What is claimed is:

1. An artificial limb having a rigid outer shell, a stump socket carried in said shell, said socket including flexible pads carried adjacent and in contact with an inner wall of said outer shell of said artificial limb, a substantially rigid cellular structure carried in a closely fitting relationship in said outer shell, said rigid cellular structure encompassing said flexible pads, and said pads being substantially less rigid than said cellular structure for providing a reinforced cellular supporting structure, and said cellular structure having a cavity therein with an inner wall complementary in shape with the users limb stump.

2. The stump socket set forth in claim 1, wherein an upper portion of said cellular supporting structure is coated with a layer of smooth plastic coating for adding wearability thereto.

References Cited UNITED STATES PATENTS 2,578,019 12/1951 Ryan 3l9 2,947,307 8/1960 Hoppe 128-90 3,035,280 5/1962 Hacklander.

3,309,714 3/1967 Porten 320 3,377,416 4/1968 Kandel 3l9 XR OTHER REFERENCES Plastic Appliances Moulded Direct to Patient by J. B. Brennan, The Lancet, Apr. 23, 1955, pp. 841-844.

Orthopaedic Appliances Atlas by J. W. Edwards, volume 2, Artificial Limbs, Ann Arbor, Mich., 1960, pp. 274277 relied upon. Copy in Group 335.

RICHARD A. GAUDET, Primary Examiner R. L. FRINKS, Assistant Examiner US. Cl. X.R. 26446, 222

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2578019 *Aug 16, 1950Dec 11, 1951Ryan Catherine MArtificial limb
US2947307 *May 20, 1955Aug 2, 1960Bayer AgPlastic foam splint
US3035280 *Aug 16, 1956May 22, 1962Agricola Reg TrustMethod of working expanded plastic and articles made by the method
US3309714 *Jan 27, 1964Mar 21, 1967Laurence PortenPneumatic cushion socket with a porous filler
US3377416 *Jan 22, 1965Apr 9, 1968Edward J. KandelMethod of making liner for artificial limb
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4397048 *Sep 21, 1981Aug 9, 1983Chas. A. Blatchford & Sons LimitedReinforced plastics artificial limb component and method for making same
US4735754 *Aug 18, 1986Apr 5, 1988Horst BucknerMethod for fabricating artificial body parts
US4783293 *May 29, 1986Nov 8, 1988Otto Bock Orthopaedische Industrie Besitz-Und Verwaltungs-Kommanditgesell SchaftProcess for manufacturing an inner conical recess for receiving an amputated extremity
US5258036 *Jan 15, 1992Nov 2, 1993Carapace, Inc.Body part mold and method of making
US5328652 *Jun 19, 1992Jul 12, 1994Protective Athletic Designs, Inc.Method for making a foamed goal pad for hockey
US5603122 *Mar 20, 1995Feb 18, 1997Kania; BruceForm-fit sock
US5728167 *Jan 11, 1995Mar 17, 1998Lohmann; Klaus H.Prosthetic sock for reducing movement between residual limb and prosthesis
US5746772 *Jan 13, 1997May 5, 1998Ja-Bar Silicone Corp.Prosthetic socket
US5800572 *May 24, 1996Sep 1, 1998Loveall; William H.Arm socket and attached hand prosthesis
US5830237 *Mar 5, 1996Nov 3, 1998Ohio Willow Wood CompanyGel and cushioning devices
US5931872 *Mar 16, 1998Aug 3, 1999Lohmann; Klaus H.Prosthetic sock for reducing movement between residual limb and prosthesis and method for use
US6406499Aug 10, 1998Jun 18, 2002Ohio Willow Wood CompanyGel and cushioning devices
US6923834May 3, 2002Aug 2, 2005Ossur HfArtificial limb socket containing volume control pad
US6936073Oct 4, 2001Aug 30, 2005Ossur HfArtificial limb socket containing volume control pad
US6964688Oct 15, 1999Nov 15, 2005Ohio Willow Wood CompanyTube sock-shaped covering
US7240414 *Feb 6, 2004Jul 10, 2007Taylor Sr Matthew TProsthetic interior casting process and product
US7291182Jul 23, 1998Nov 6, 2007The Ohio Willow Wood CompanyGel and cushioning devices
US8317873Feb 23, 2010Nov 27, 2012The Ohio Willow Wood CompanyPolymeric prosthetic liner with controlled stretch characteristics
US8323353 *Nov 14, 2010Dec 4, 2012Randall D. AlleyMethod for use of a compression stabilized prosthetic socket interface
US8523951Dec 22, 2008Sep 3, 2013The Ohio Willow Wood CompanyProsthetic socket interface and assembly
US8656918Dec 22, 2011Feb 25, 2014Randall D. AlleyMethod, system, and tool for affixing compression stabilized prosthetic socket interface
US9265629Sep 6, 2013Feb 23, 2016The Ohio Willow Wood CompanyFabric covered polymeric prosthetic liner
US20020103545 *Mar 28, 2002Aug 1, 2002Ohio Willow Wood CompanyGel and cushioning devices
US20050101693 *Nov 6, 2003May 12, 2005Ohio Willow Wood CompanyGel and cushioning devices
US20050173829 *Feb 6, 2004Aug 11, 2005Taylor Matthew T.Sr.Prosthetic interior casting process and product
US20050240283 *May 2, 2005Oct 27, 2005The Ohio Willow Wood CompanyTube sock-shaped covering
US20090076625 *Sep 14, 2007Mar 19, 2009The Ohio Willow Wood CompanyReinforced prosthetic suspension sleeve
US20090132056 *Dec 22, 2008May 21, 2009The Ohio Willow Wood CompanyTube sock-shaped covering
US20090240344 *Mar 19, 2009Sep 24, 2009The Ohio Willow Wood CompanyMulti-layer polymeric prosthetic liner
US20090310364 *Jun 16, 2008Dec 17, 2009Cornelius TurnerAttachable illumination accessory for walker
US20110208321 *Feb 23, 2010Aug 25, 2011The Ohio Willow Wood CompanyPolymeric Prosthetic Liner With Controlled Stretch Characteristics
EP2705810A1 *Sep 5, 2013Mar 12, 2014Fulvio MarottoMethod to make a negative cast for articular prostheses, corresponding apparatus and cast thus made
WO1992008425A1 *Nov 13, 1991May 29, 1992Rigal FrancoisAmputated limb prosthesis
WO1996009077A1 *Sep 11, 1995Mar 28, 1996Joerstad DagMethod for fitting prostheses directly on users and a prosthesis according to the method
Classifications
U.S. Classification623/36, 264/222, 264/46.6
International ClassificationA61F2/78, A61F2/80
Cooperative ClassificationA61F2/80, A61F2002/7818, A61F2/7812, A61F2002/5052
European ClassificationA61F2/78C, A61F2/80