US 1907511 A
Description (OCR text may contain errors)
May 9, 1933.
C. H. DAVIES COMPOSITION SOCKET FOR ARTIFICIAL L EGS Filed July 5, 1931 lNI/ENTOR dz&; ATTORNEY WITNESS:
Patented May 9 1933 UNITED STATES" cmms 1i. navms, or rmLamiLrniA, rmmsnvanm COMPOSITION SOCKET F63 ARTIFICIAL LEGS Application filed m a,
the amputated stump and tries to duplicate this shell by carving out of a solid block of a wood various bone projections, and also attempts to provide, suflicient room for the irregular and tender stump. The results obtained depend solely upon his judgment.
The task outlined is laborious and the results are always in question. Several fittings are necessary, frequently painful to the patient. After several hours of fitting, the patient is then obliged to tell the wood socket builder what result has been obtained, and whether or not the fit is comfortable. Obviously it is difficult if not almost impossible for the wood socket builder. to du plicate the shell cast of the amputated limb with its various indentations, bone projections and irregular shape, and to construct a comfortable fitting socket to which the patient is justly entitled.
In the construction of leather sockets, a shell plaster of paris cast is taken of the stump. This cast is then removed from'the stump and filled with liquid plaster of paris.
After hardening, the outer shell is removed from the plaster cast, leaving the solid cast, which is a du licate of the stump of the amputated limb The bone projections-are built up according to the mechanics skill. Em iricism is again evident, and the fit of t e leather socket also depends upon the judgment of the socket builder. The leather is saturated with water and stretched afiound the cast, and thereafter hammered around the proj actions, the hammering being done to bring out more prominentlytindentations essential to the fit. The leather is now dried, and in drying contracts and provides a base, and is sanitary, waterproof, and emconcentrated steam under a pressure of 30.
heated to 212 degrees -F. is applied as de- 1981. Serial-No. 548,642.
socket that fits the stump fairly well. This socket is then attached to the shin piece of the limb and 'a second layer ofleather is built around the first to reinforce it..
The disadvantages of the leather socket are its flexibility, the absorption'of perspiration, the excessive weight, and an occa-- sional secretion of matter from the leather which becomes a serious irritant to the stump. When a leather socket becomes wet, m the fit is quite naturally afi'ected.
My invention relates to a perfect fitting composition socket for artificial limbs, which socket is absolute and positive in securing an accurate reproduction of the cast, theref by providing a comfortable fit Without dependingupon the skill of the operator. Empiricism-is eliminated, and the operator per orms his work in a scientific and accu-: rate manner. A comfortable and accurate fitting socket can be built by this method by the average laborer and in one-fifth of the time required to construct a wooden. socket, or one-third of the time required to construct a leather socket, and in addition eliminates one-half of the weight and material, and is surprisingly economical. Due
to its strength, apertures or health holes may be perforated in the composition perfeet fitting socket, to permit air toget to the stump. Moreover, the article is extremely light, a most acceptable feature to the limb wearer.-' r
The material used has a nitrocellulose pervious to perspiration. Due to its remarkable strength, it can be inserted into the metallic shin' or attached to a wooden shin of an artificial limb and is permitted to hang freely as illustrated in the accomvpanying drawing.
'Shouldit become necessaryfor the bone projections already provided for in the cast, and built up by felt pads, togive more room,
pounds is applied by flexible tubular means to the exact spot where relief is necessary. As the steam is applied to thespot, the action is the same as when the hot water scribed below, for softening the tube. The operator presses the socket. out at this point, thereby giving suflicient room to warrant immediate relief without cutting the material and thereby weakening the socket.
In the drawing,
Figure 1 is in section and elevation, and shows the mold being formed on-the stump.
Figure 2 is in section and elevation and shows the mold filled with plaster of paris.
Figure 3 represents the element thus cast in elevation;
Figure 4 illustrates in perspective a composition tube to be shaped in forming the socket.
Figure.5 shows a tapering mandrel in elevation, the tube after being moistened and heated and stretched, being .in section and surrounding the mandrel.
Figures 6, 7, 8, partly in vertical section, show further steps described below.
Figure 9 shows the completed socket applied within the upper portion of the'limb.
The procedure for the construction of this composition perfect fitting socket for the amputated limb is as follows:
In Figure 1 the projections the bone 1 are assumed to built up with small felt pads caused to adhere to the stump. Then a sock is drawn over the stump, and plaster of paris is applied as shown at 2 and is built upto one-fourth .of an inch in thickness. Figure 2 shows the mold filled with liquid plaster of paris 3 and this is permitted to harden and con-- statutes an exact duplicate of the stump in-' cluding the projections. The outer material is cut away,'leaving the element 3, in solid form. f
. vA composition tube 5 including nitrocel- .lulose as its base material, is shown in Figure 4. The characteristics of this material and the advanta for using it in the building of sockets or artificial limbs are that when immersed in hot water and heated to 212-degrees F.,'it will soften,-so that it may be stretched, and after having been stretched it is permitted to cool. When again inserted into hotwater, it ori a1 size.
igure 5 shows a 'tubenitrocellulose stretched around a tapering mandrel 6. The
- end of the tube is smaller in diameter than the end of the cast element 3.- The tube 5 takei. out of the tubing, and the element 3 is inserted as-in-Figure 6. The u per end ..of the tubing has been lapped at to provide 'a shoulder to rest on the top of the at the point 12.
A. B. 'o. of
will contract to its metal shin 11. at point 12. The assembled I elements of Figure 6 are then re-inserted into hot water and heated. to 212 degrees F.
The characteristic of the material when heated a second time is to shrink back to its original size (Figure 4). The tube then becomes an exact duplicate of the cast ele-.
not shrink. Theshell 5 having the covering 8 provides a perfect fitting composition gnated with pyralin and socket and is then inserted into the metallic shin 11 and rests on the seat 7 Figure 9,
In most instances D in the calf of the limb. In order to se-' cure the close fit of the socket at this point,
the atrophied stump is' smaller than the good limb.. The artificial and eliminate'all possible lost motion, vertical movement oririction, celastic is wrapped around the shell 5 as in Figure 9, tofill in this portionof the limb. The shell is now riveted to the metal or wooden shin at point 13 and the structure is complete.
It may be observed that the essential orm the socket 5 are,: first, that it is-hard at atmospheric temperatures; second, capable of bein rendered temporarily soft'and self to the precise details of construction or a ment or method of. procedure herein set. forth, as it' is obvious that various modifications may be. made therein without de parting from the essential features of my invention, as defined in What I claimis:
1. The method of forming a socket of properties of the cellulosic composition to the appended claims; I
hardened plastic cellulosic material for 1511- an artificial limb, to fit the atrophied natural stump of an amputated limb; which consists 'in making thereb forming a matrix "conforming to the.
, conical .form of said. stump; 1e-- moving said matrixv from the. stump and V a cast' of plastic material around said stump andthe artificial stump 'of plastic material;
rendering plastic a primarily cylindricaltube of cellulosic material which is at atmospheric temperature, by heating .1t to.
thetube and form a shoulder; causing said conical tube to, harden in such distended form; inserting the artificial stump in that hardened tube of conical cellulosic material;
again heating said tube of cellulosicmate rial to approximately 212 F., and allowing it to cool, shrink, and-harden upon said artificial stump, to form a socket which will fit the natural stump; removing the artificial stump from said hard cellulosic socket; fitting said socket of cellulosic material in an artificial limb of rigid material; and securing it in said artificial limb, so positioned that when the natural stump is inserted therein said artificial limb is presented in proper relation with said stump to resemble the amputatedlimb.
2. The method of forming a socket of hardened plastic cellulosic material for lining an artificial limb, to fit the tapered atrophied natural stump of an amputated hmb; which consists in forming a matrix conforming to the irregular conical form of said stump; casting plastic material in said matrix to form an artificial stmnp, resembling the natural stump; rendering temporarily plastic a tube of cellulosic material which is hard at atmospheric temperature; stretching said tube to a conical. tubular form,
large enough. to receive said artificial stump;
turning down the edge of said tube at its larger end to overlap the outside of the tube and form a shoulder; causing said conical tube to harden in such distended form; in-
serting the artificial in that hardened tube of cellulosic material; again rendering 'said tube ofcellulosic material'temporarily the wallof the limb includes means for preventing lost motion of the socket in the limb.
5. A socket of hardened lastic cellulosic material for an arti cial limb, to fit the tapered atrophied naturalstump of an amputated limb; consisting of an irregular conical tube, open at both ends, with its inner surface shapedto substantially the same configuration as the outer surface of said stump; the larger end pf said socket having an external shoulder overhanging and resting upon the adjacent end of said artificlal limb; said shoulder being formed by and in unitary relation with the cellulosic material of the socket.
6. A method as in claim 1, including the step of providing the socket with a covermg formed of fabric before inserting it in the artificial limb; whereby, said fabric covering is interposed between said socket and the inner surface of the limb.
ture. V 7 v CHARLES H. DAVIES.
' plastic, and allowing it to shrink and harden upon said artificial stump, to. form a socket which will fit the natural stump; and securing-said hard socket of cellulosicma-s terial in an artificial limb of .rigid material, so positioned that when the natural stump is inserted therein said artificial limb is presented in proper relation with said stump toresemble the amputated limb. 3. A socket of hardened plastic'c'ellulosic material for lining an artificial limb, to. fit i the tapered 'atropliied natural stump of an amputated limb; consisting of an irregular conical tube, "open at both ends, with its inner surface shaped to substantially the same configuration as the outer surface of said stump; the larger end of said socket shaped to fit, in contact-with, the wall of said limb, and means for holding the smiilller end of said socket spaced from said Wa means for holding said socket spaced from In testimony whereof I afiix my signa-