US2851694A - Artificial leg - Google Patents

Description

Sept. 16,1958

Filed June 20, 1955 M. CAPELLA VALENTl ARTIFICIAL LEG 4 Sheets-Sheet 1 lNVENTO R MARIO CAPELLA VALEN r:

P 1953 M. CAPELLA VALENTI 2,851,694

ARTIFICIAL LEG 4 Sheets-Sheet 2 Filed June 20, 1955 INVENTOR l MARIO CAPELLA VALENTI p 1958 M. CAPELLA VALENTI 2,851,694

ARTIFICIAL LEG Filed June 20, 1955 4 Sheets-Sheet 3 Se t. 16, 1958' M. CAPELLA VALENTl 2,851,694

ARTIFICIAL LEG Filed June 20, 1955 4 Sheets-Sheet 4 Fig.3

Fig. 10

INVENTOR MARIO CAPELLA VALENT! .leg or part thereof of the wearer. "bers are interconnected through anarticulated shaft and .through a springmember associated with a braking or the leg or part-thereof of the wearer.

United States Patent cc This'invention relates to tin-artificial leg with a correspondingfoot for below-knee amputees or for deformed :persons with considerable shortening of one lower extremity. In both cases the person equipped with the apparatus according to the invention .is able to walk in :a substantially normal way both over flat: ground and it over inclined or undulating ground.

This invention is an improvement in or development =1of..the artificial'foot described in the applicants earlier sPatent No. 2,446,042,whichrelates:solely to an'arti- .:ficial. 'foot'comprising a hollow foot within which is a -mechanism comprising two members which are articulated .to one another and one of which .is connected to thesbase of the artificial foot, whilethe othermember is connected to a framework or assembly fixed to the The said two memdamping member.

vThe device according to the present invention com- .prises both foot andleg. The artificial foot is alsohollow and contains the articulation mechanism consisting of two parts, one of which is fixed to the base of the hollow foot and the other of which is fixed to a framework or assembly associated with the artificial leg and fixed to The two parts of the foot are articulated to one another by means of a shaft disposed at the level of the normal ankle jointand .are interconnected through the medium of a 'rod or spring-loaded"connecting member which always :returns .thefoot to :the initial position after an oscillation of the :.foot during walking. The :said'mechanism also 'comprises-awetarding or friction .member which acts upon the said spring-like member in order to vary the action Ithereof accurately, constantly and operatively in dependence upon the inclination ofthe groundover which the wearer iswalking. With thisarrangement, there- :sult is obtained that a person equipped with this artificial'foot and leg can walk withoutdiificulty .over any type of ground whatever the inclination and nature thereof but does;not'undergo any more fatigue than would be felt by a normal person walking over this type of ground.

For a better understanding of the invention andto show 'how' the same canbe :carried intoeifect, reference "will now be vmade to the accompanying drawings,

wherein: p 1

Figure 1 is aside elevation of thecombin'ation forming the artificial "foot' and bywhich is fitted in this case mechanism within the hollow'foot, in the same position as Figure 1;

Figure 4 is a'front elevation of the last-mentioned I mechanism;

2,851,694 Patented Sept. 16, 1958 Figure 5 is a verticalsection thereof :along'theline V--V of Figure'4;

Figure 6 is an outer, partcutaway viewfrom the side "opposite'to that shown in Figure 3;

:nism contained in therfoot as:shownin Figure' 8, whilst Figure 10 is a section 'alongthe line X-X*:of Figure- 9.

The form of construction illustrated: inFigures .1 'to 71is particularly suitable for cases where the legdias ibeen amputated below the knee, andcomprises 'aihollow'ffoot formed by two parts 1-'2 whichacontain the articulation mechanism of the saidfoot, which is in turn combined with a metal framework. or assembly which forms the artificial leg proper and which is fixed to the wearers stump. This fixing assembly must obviously vary in dependence upon the conditions-.ofzeach case, but inmost cases the arrangement illustratedin Figuresl and 2 will be used for amputees.

In order to ensurethat sthe-,foot.,1-can execute the movements necessary. for walking as if itwere'a normal foot, the two halves '3 and 5.of..t l 1e mechanism are interconnectedthrough thetrnedium of'a resilient rodtor resilient connecting member formed by .arhollow cylinder 10 articulated at 11 to the upper half 5.and having in. its interior a rod 12 terminating in a piston-like disc '13 actuated by a spring .14. .The bottom .ofthe rod 12 is articulated, through the medium of the shaft 15,to lugs 30 associated with a member 28 situatedin the lower. half 3. While the wearer is walking over fiat ground, the articulation shaft 15 remains stationary =and.serves as abearingpoint for the spring-loaded rod 10, with,the resultthat, when the wearer rests .the foot on the ground while walking and when thespring14 is compressed, the lower member 3 andlfoot ,1 can return to the initial position from the instant that thiscompres'sion ceases.

In order to facilitate movement of the foot Without tiring the wearer when he is walking'up or down an incline, it is arranged according to theinvention that the articulationpoint v15 of the. ro'd,12:can change its position in dependence upon the inclination of the ground and upon the direction ofmovement in .order that the foot 1, when lifted clear ofthe, ground during movement along an inclination, may not return.of itself into the position as shown in 'Figurel but may. remain in a position which is always related to the direction of the ground. The result is therefore .obtained that the wearer need not make. an effort ateverystep to adapt the 'foot to the inclination of'the ground even in the case in which, while the wearer is walkingralong a slope, the direction thereof or of walking changes abruptly.

To this end, there is disposed in the lower'half 3 of the mechanism a short tubular piece 20 within which is a helicoidal spring 19, one of the ends of which is fixed to the cover 21 fixed to the member-3, and the other end of which is fixed to a cover 22'having projections 23 engaging in recesses '24 in the short tubular piece 20.

The latter isfixed to the lower'half 3 of the'mechanism by meansof a clamp" 25fixed to the base of themember 3 by-screws 26 and adapted to 'be' tightened by means of the screw 27. The soleobject'of the clamp 25- isto' act as a brake upon the cylinder 20. The pressure of .the

clamp 25 is always 'regulated in "dependence 'upon' the able to turn when thewearer displaces "the "centre of gravity of :his body aas=occurs in walking up ordow-n 3 inclines, when the piece 20 adapts the foot to inequalities of this type.

Also fixed in the piece 20 is a second clamp 28 which is tightened by means of the screw 29 and which has at its upper end lugs 30 to which the end of the rod 12 is articulated by means of the shaft 15. The clamp 28 determines the point of articulation 15 for the rod 12 and thus transmits to the foot 1 the movement which may be experienced by the body of the wearer according to the position of his centre of gravity, depending upon the steepness of the inclination of the ground over which he is walking. Moreover, by slackening the clamp 28 it is possible to adjust the mechanism, the tensioning of the spring 19 in the piece 20 being varied in dependence upon the muscular force of the wearer and as the complement of the pressure exerted upon the said piece 20 by the clamp 28 through the medium of the action of the screw 29.

One of the lugs 30 has a lateral projection 37 which, when the piece 20 turns with the clamp 28, slides upon a curved part 38 of the metal sheet forming the lower part of the mechanism. The curvature of the said metal sheet is such as to limit the movement of the articulation 3015.

When the wearer is walking over fiat ground, the piece 20 and the members associated therewith take up the position shown in Figure 5, and movement of the foot only occurs in one direction which is the direction of dorsal extension and which is due to the weight of the wearers body at the instant of walking, while the return movement is due solely to the action of the spring 14.

On the other hand, when the wearer has to pass from flat to inclined ground, the displacement of the centre of gravity of the body mass exerts a greater force upon the movable part of the foot, so that the piece 20 together with the clamp and helicoidal spring 19 causes the articulation shaft 15 of the spring-loaded rod 12 to vary its position automatically, the foot 1 thus being enabled to adapt itself to the inclination of the ground upon which it is resting. Thus, when the wearer lifts the foot clear of the ground, the sole of the foot remains not in a horizontal position but in a position which is always dependent upon the steepness of inclination of the ground, with the result that, when the wearer bears upon the foot again, he does not have to make any effort to adapt the foot to the inclination of the ground.

The artificial leg proper, that is to say the framework for fixing the artificial foot to the part 16 of the wearers leg is formed by vertical members 3132 on each side of the upward extension 8 of the foot. Fixed in the top of the members 3132 is a short metal tubular piece 33 which is adapted to the leg below the knee. The free ends of the tubular piece 33 are articulated by means of shafts 34 corresponding to the rotational centre of the knee, to upper upwardly extending parts 35 which support a second brace 36 which fits the front half of the thigh somewhat above the knee, the brace 36 being fixed to this part of the thigh by means of straps 17-18.

The short tubular piece is a metal member produced from a moulding taken of the stump or terminal part of the wearers leg 16, the said member 33 being such as to surround completely the stump and to be completely adapted to the contour thereof. On the other hand, the bottom of the tubular piece 33 is opened so that the leg 16 projects downwardly as indicated by the chain lines in Figure 1. In this way a very intimate fit is obtained of the tubular piece 33 upon the leg 16, the lower end thereof being left free so that the artificial foot can be worn with greater comfort.

The upper brace 36 is also made of metal and is also constructed from a moulding of the part to which the brace 36 is to be applied in order to obtain an exact fit. The central part of the front face of the brace 36 has a relatively large aperture having the double purpose of reducing weight and of permitting to the greatest pos- 4 sible extent the wearers leg to perspire and to come into contact the air.

In this way the artificial foot according to the invention can be conveniently fastened to the wearers leg and thigh, and the wearer can walk normally on any type of ground whether the same is fiat or inclined, hard or soft.

If this artificial foot is to be fitted to a person with a considerable shortening of one leg, the form of the fixing frame or artificial leg must be modified, and suitably the construction of the hollow foot is also slightly modified in order to adapt the same to the wearers foot, this modification is illustrated in Figures 8 to 10.

The framework for fixing the artificial foot to the wearers leg comprises a plate 45 which is adapted to the sole of the wearers foot and which is articulated at 46 to the mechanism within the artificial foot. The plate 45 is connected to the foot by means of a brace 42 and extends upwardly to form another brace 43 which is fixed to the wearers leg. In this case, the artificial foot comprises a hollow foot 41 which is similar to the part 1 of the foot as shown in Figure 1 and which contains the mechanism which is substantially identical with the mechanism as shown in Figures 3 to 7 and which operates in the same way as the last-mentioned mechanism.

The mechanism of the foot as shown in Figures 8 to 10 comprises a stamped sheet-metal framework 47 which is fixed to the sole of the hollow foot 41 and which has lateral lugs 48 by means of which the framework 47 is fixed to the lateral walls of the hollow foot 41. The framework 47 has secured to itself the clamp 25 which is arranged to rub against the tubular piece 20. The latter is also surrounded by a clamp 28 which in this case extends rcarwardly, forming the articulation point 15 of the spring-loaded rod 10. The upper part 5 of the mechanism as illustrated in Figures 3 to 7 is substituted in Figures 8 to 10 by the plate 45 which is connected to the wearers foot and with which is coupled the end of the spring-loaded rod 10. The articulation shaft 6 as shown in Figures 3 to 7 is substituted in this case by the articulation shaft 46 linking the plate 45 with the mechanism framework 4748.

The operation of this form of construction is exactly as hereinbefore described with reference to Figures 3 to 7.

I claim:

1. An artificial leg comprising a hollow foot-shaped member having an upper and a lower part, an internal mechanism having an upper and lower part mounted within said foot-shaped member, said upper and lower parts of said internal mechanism being articulated to each other at the level of a normal ankle joint, a spring loaded rod articulated on the upper part of said internal mechanism, torsional spring means having one end connected to said lower part of said internal mechanism, a tubular member surrounding said torsional spring means to which the other end of said torsional spring means is connected, a clamp on the lower part of said internal mechanism in which said tubular member is rotatably clamped, a second clamp rotatably clamped on said tubular member and having a pivot thereon to which the other end of said spring loaded rod is articulated, an upwardly directed extension on the upper part of said foot member, and means thereon for attachment to a wearers leg.

7 2. An artificial leg as claimed in claim 1 in which said second clamp has a plurality of lugs thereon and a shaft between said lugs forming the pivot for the articulation of the end of said spring loaded rod, a lateral extension on one of said lugs, and an arcuate portion on said lower part of said internal mechanism against which said extension bears for limiting relative movement of said upper and lower parts of said internal mechanism.

3. An artificial leg as claimed in claim 1 in which said attachment means comprise a cylindrical metal part on said extension fitting around the part of a wearers leg below the knee, and a metal brace on said extension for fitting around the thigh of a wearers leg, said extension being articulated between said cylindrical metal part and said metal brace at a point corresponding to a wearerfs knee.

4. An artificial leg as claimed in claim 3 in which said cylindrical metal part is shaped in the form of a wearers leg from below the knee to above the end of the leg, whereby the lower end of the leg is incompletely enclosed.

5. An artificial leg as claimed in claim 3 in which said metal brace has a large aperture therein.

6. An artificial leg as claimed in claim 1 in which said means for attachment comprise a plate on said upper part of said internal mechanism for receiving the sole of the foot of a wearer, and means for attaching said plate to the foot, ankle and lower leg of a wearer, said spring loaded rod being articulated to said upper part 0n the bottom of said plate.

References Cited in the file of this patent UNITED STATES PATENTS 9,232 Drake Aug. 31, 1852 2,542,436 Schultz Feb. 20, 1951 10 2,594,751 Fahlstrom Apr. 29, 1952 FOREIGN PATENTS 628,958 Great Britain Sept. 8, 1949

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