US2545146A - Artificial limb - Google Patents

Description

March 13, 1951 R. R. HYDORN ARTIFICIAL LIMB 2 Sheets-Sheet 1 Filed Feb. 25, 1949 Alfil INVENTOR. H/dolm.

A T'TORNE YS R. R. HYDORN ARTIFICIAL LIMB March 13, 1951 Filed Feb. 25, 1949 IN V EN TOR.

A TTOR/VE YS'.

m. fw M Patented Mar. 13, 1951 UNITED sTATEsPATENT orifice l This invention relates to artificial limbs and particularly to such limbs constructed of lightweight materials and employing inflatable means to assist in supporting the weight of a wearer.

In general the invention contemplates an artificial limb comprising. limb sections in the form of hollow shells appropriately hinged together at the joints. An inatable bag is formed tooccupy the .interior of the entire limb structure, extending across the joints, to assist in supporting the weight of the wearer and performing the' additional function of returning the pivotedsections to a normal predetermined position after flexure.

It is an object of this invention to provide, an artiicial limb of extremely light-weight construction yet having sufticient strength and rigidity for its intended purpose.

It is another object of this invention to provide an articial limb'including pivoted joints wherein an inflatable member assists in supporting the weight of a wearer and in addition acts to return parts to a predetermined normal relative relationship.

It is a still further object of this invention to provide an articial limb having relatively hinged portions capable of being quite freely pivoted in one direction, during walking or the like, and including means to retard the return of those parts to normal position.

Further objects and advantageswill become apparentl as the description proceeds in connection with the accompanying drawings wherein: A Fig. l is a side elevational view of an artificial limb embodying the principles of the present invention. Y

Fig. 2 is a vertical sectional view through the embodiment illustrated in Fig. 1. Y

Fig. 3 is a fragmentary Vertical sectional view taken substantially along the line 3--3 of Fig. 2.

Fig. 4 is a fragmentary sectional View taken substantialy along the line 4-4 of Fig. 2.

Fig. 5 is a sectional View through the foot section substantially valong the line 5-5 of Fig. 2.

Fig. 6 is a fragmentary,.vertical, sectional view, similar to Fig. 2 but illustrating a modified form of knee joint, and

Fig. '7 is a view similarto Fig. 6., illustrating the parts in different relative positions.

Referring now to Fig. 1, numeral I indicates an upper leg section having a leather boot 2 xed thereto in a manner to be described. A lower leg section 3 is pivoted to the upper section I, as at 4, by means of an anti-friction ball bearing joint 5 provided in opposed ears extending from the sections I and 3. The ears referred to are further provided with inter-engageable abutments, at 5a, to limit. pivotal movement in 4one direction. A fcotsection 6 has pivoted thereto a toe section 'I on ak transverse axis 8 and the foot section is, in turn, universally mounted relative to the lower leg section 3 in a manner to be described.

*.terial.

ential groove 9.

Referring now to Fig. 2 the upper leg section I, the lower leg section 3 and the-foot section 5 are of hollow, shell-like construction and are preferably made of-relativelylight-weight materials such as aluminum or magnesium but may, if desired, be made of steel or any other suitable ma- The upper leg section I is provided with a circumferential groove 9 adjacent its lower end and its upper edge I0 is preferably bevelled or feathered to avoid the presentation of an abrupt vshoulder at that point. The-leather boot 2, previously referred to, has a ring or band of leather I I sewed or otherwise affixed theretovat its innervmost lower end and positioned in the circumfer- Upon lacing the boot to the upper leg section, as indicated in Fig. 1, the ring or band II acts as a key or locking means to retain the boot in fixed position on the upper leg section I.` Y I The foot section 6 is provided with a generally circular opening I2 at its uppermost portion and the opening I2 is surrounded by a generally horizontal abutment or shoulder'I3/ which may be provided with an annularl channel-like seat to receive the lower end ofk a helical compression spring I4. The lowermost portion of the lower leg section 3 is provided with a generally spherical outer surface I5 of a diameter somewhat less than that of the opening AI2 inthe foot section. The leg section 3 is further provided with a downwardly facing shoulder or channel I6 forming a seat or abutment for the upper end of theV spring I4. (The lower terminus of the leg section 3 extends downwardly into the opening I2 and the clearances therebetween are sufficient to permit the upper leg section to swing in any vertical I plane relative to the foot section. The spring I4y vwill prevent the leg section 3 from dropping 'through the opening I2 and wedging itself therein and is of sufficient strength to-support a -substantial portion of the weight of the wearer. Adjacent the shoulder I6 and on opposite sides of the leg section 3, the limb is provided with abutments I1 (Figs. 1 and 3) extending outwardly beyond the outer edges of the spring I4. The abutments I'I are positioned directly above upwardly and outwardlyextending ear portions I8 on the foot section 6. The ears or rockers I8 are provided with upper surfaces curved in a fore and aft direction. It will be apparent from Fig. 1, that if the weight applied to the limb is excessive or if shock loads are applied, the engagement of the abutments I1 with the ears I8 will prevent further telescoping of the leg section 3 into the foot section and provide a stop means at that point. In addition to acting as a limiting stop, inter-engagement between the portions I'I and I8 willpermit the leg section 3 to rock or roll on the curved surfaces of the ears I8 in a fore and aft direction, thus permitting the user to walk in a normal manner, even with the section 3 in its lowermost position. In addition, the ears I8 at all timeslimit the lateral swinging of leg section 3 to an amount less than its permissible fore-and-aft pivotal movement.

A hollow, inflatable bag member 2B is molded or otherwise formed to have a normal shape substantially complementary `to the space inside the assembled limb, including at least 'aportion of the foot section. `This inflatable bag may be made entirely of rubber or maybe formed from fabric or other reinforcing material, treated in a suitable manner to renderit impervioustc air. The upper end of the bag 2D is provided with a reinforced, relatively thick and generally flat portion 2I having shoulders Z'Z'resting upon suitable abutments provided in the upperleg section I. A pad'or cushion of sponge rubber `or other suitable Ymaterial v23 is positioned within the upper leg section l and rests upon the reinforced upper 'end 2l of the bag 20. In use the bag 25 is inflated and the boot 2 may be laced to the wearer with the stump ofthe wearers natural limb resting upon the cushion or pad`23. By this arrangement it will be apparent that the vinflatable bag-20 provides a `resilient supportior joints the bag 20 is -formed with inwardly turned portions 24 and 25. These inwardly turned portions deiine restricted necks or -passageways between sections of the limb. The inturned por tions at the rear 'of the knee jointA are thickened considerably, as at '2.6, and provided with suitable reinforcing means l(not shown) to yrender them substantially rigid and inflexible `adjacent the outer surfaces of the bagf. The inturned portions at 25 are likewise provided with suitable reinforcing means rendering :them substantially rigid and `are vso formed and shaped that when fully inflated'they snugly engage the inner lower.- mostportion of the leg section in gripping engagement with a bead or ring 221 formed at the lower terminus of the section 3 and engage "the bottom thereof whereby the section B-is also supported by the portion of bag ZII in the foot section. The reinforcing means referred to may be in the form of metal inserts or successive layers of cloth imbedded in the material of the bag or such stiffenirig may be provided'by any other suitable means.

As clearly shown in Fig. 2 the thickened portions of the bag 2n at the joints are of such configuration that when the limb is in its normal position adjacent thickened portions are in direct contact with each other. The innermost portions 23 and 29 of the inturned constrictions of the bag 20 have relatively thin wall sections and vare positioned substantially symmetrically of the openings in the wall 32.

pivotal axes at the respective joints whereby ilexure of the bag may be performed with relative ease.

As also shown in Fig. 2 the inflatable bag 20 does not Vcompletely iill the hollow foot section but terminates short of the toe section in a generally vertical end wall or partition 30. The remaining space within the foot section is occupied by an inflatable bag 3I s0 shapedas to be snugly'received'within the remaining space. The small bag 3i has an end wall 32 abutting against the end wall 39 of the bag 20. The walls 30 and 32 are each provided with a pair of openings and the openings in the wall are aligned with the In one pair of aligned openings a one-way or check valve 34 is positioned and in the other openings a member 35, having a restricted passageway 32S therethrough, is positioned. The check valve 34 comprises a valve body having an outwardly extending flange 31 and a spring-pressed valve element S5 urged toward an opening 3B in the said valve body. The end of the valve body opposite `theflange 31 is preferably threaded as at to receive 'a clamping ring 4I to position the valve in the composite partition wall in fixed and air-tight relation thereto. It will be apparent that the one-way valve described provides for rapid and `easy passage of air through said valve in one direction and blocking of the return of said air in the Yopposite 'direction through said valve. The one-way valve structure described is merely illustrative and may be replaced by any .suitable arrangement to permit air to be readily passed in one direction only from the interior of the (small bag 3l to the interior of the large inflatable bag 2B.

In the other pair .of aligned lopenings previously referred to the memberor plug A35is held in fixed position by means of a threaded clamping ring 42 clamping the periphery of the openings against an opposed flange 43 in an obvious manner and in the manner described in connection with the valve 34. As stated,the member S5 is provided with a restricted opening 3S therein, which opening provides a small passageway between the interiors of the bags and3l. The effective size of the opening 35 may be varied by adjustment of a control member l44 threaded through the element .35.and having a head 45 provided with a screwdriver slot 46. The control element d extends outwardly .between thewalls 30 and 32 andthe head 45 thereof plies inwardly of an .opening 47 (see Fig. 1) `provided in a side wall of the outer shell of foot section B. The inner endof the element 4.4 maybeextendedinto or withdrawn from the opening 36. The control member 44 described. is merely .illustrative and any other suitable means may be employed to control the effective size of the passageway .33. Preferably suchcontrol means will be accessible to and manipulable 'from the outside of the foot section.

The forward portion of .the foot section 6 is open/as at 48, and a bracket 49 is fixed to the interior of the foot shell. The bracket 49 provides a bearing support upon which the toe section 'I may be pivotally'mounted on the transverse axis 8. vThe toe section 'I is furtherprovided with an inwardly extending tongue 50 which extends inwardly of the foot vsection beyond the axis 8 and into contact with the outer surface of the small bag 3 I.

A valve 5I, of any suitable type of construction, is provided in the inatablebag v2Il and is positioned inwardly of opening 52 inthe leg section 3 whereby the valve is readily accessible for the inflation of the bag 2o or for the regulation of air pressure within said bag. The valve 5I will preferably be formed to extend inwardly of the bag 20 to avoid outwardly projecting parts.

In use, the wearer may swing the artificial limb forwardly to an advanced position and upon transferring his weight thereto the knee joint and the toe section will pivot under his or her weight in a manner simulating the action of a natural limb as the body moves forwardly. As the wearers body moves forwardly of the artificial limb, which then extends toward the rear, the knee and toe joints -will bend further but such bending will be opposed by the pressures within the inflatable bags. It will be apparent from Fig. 2 that upon swinging the leg section I rearwardly about the joint 4 the reinforced portions 25 at the rear ofthe knee will cause compression of thev bag 20 in a manner to resist bending at the knee joint. In like manner bending of the toe section 1 upwardly will cause the tongue 50 to be pressed inwardly of the bag 3i and will be resisted by the pressure within the inflatable bag. Pressure within the bag 3l, however, will cause some of the air therein to be transferred to the-bag 20 through valve 34 and upon release of the weight from the limb in question, in walking, and swinging of the limb forwardly, the toe section will be allowed to return to normal position under the influence of the pressure of ail` returning to the bag 3| through opening 36. Such return to normal position, will, however, be delayed since expansion of the bag 3l is limited by the restricted opening 36 so that the toe section 'l does not return to extended position before the limb has been swung forwardly, thus obviating the danger of the wearer stumbling or stubbing the toe section during the forward swinging movement of the limb. In like manner the limb is straightened to normal position at the knee joint, While being swung forwardly, due to the tendency of the bag 29 to resume its normal shape adjacent the reinforcements 26.

The upper leg section I is further provided with a depending, transversely curved, plate-like portion 60 slidably received behind an upwardly extending similar portion 6! on the lower leg section 3. During fleXure of the knee joint the portions 60 and 6l may slide relative to each other to provide a continuously closed forward knee surface. A resilient and flexible stretchable pad 62 is cemented or otherwise attached, as at 63 andV 64, to the upper and lower leg sections respectively. The attachment of the pad 62 to the upper and lower leg sections will preferably be limited to relatively small areas at the top and bottom of the pad whereby as the knee iis bent the pad may stretch or contract in simulation of a natural knee.

Figs. 6 and '7 illustrate a modified form of knee joint for an artical limb of this general type. In this modified construction an inflatable bag 2a extends across the knee joint, as in the previous embodiment, but the bag is not provided with the restricted neck portions described in connection with the earlier embodiment. The upper leg section la ls provided with a downwardly extending spring element 19, attached at its upper end to the upper leg section and extending downwardly into the lower leg section 3a and in contact with the outer surface of the bag 20a therein. The member 10 may be in the form of a ribbon of spring steel or the like.y Upon flexure of the joint to the position shown in Fig.

'7, the spring member 10 will act to compress the bag 20a and distort it to the shape shown in Fig. 7, thereby conditioning the bag to urge the sections la and 3a back to the normal position shown in Fig. 6. Preferably the bag 20a will be provided, in the normal position of the sections, with an inwardly turned portion 'H in its forward wall at the knee joint, to permit the bag to assume the position shown in Fig. '7 without a tendency to stretch its forward wall.

Although a limited number of embodiments have been illustrated herein, it is to be understood. that the specific forms of the invention shown and described do not limit the scope of the invention, which is to be limited only by the scope of the appended claims.

I claim:

1. In an artical limb, a pair of members, means providing for relative pivotal movement between said members, one of said members comprising a hollow shell, an inflatable bag in said hollow shell, said bag comprising at least two cells separated by an impervious partition, the other of said members having a portion engaging one of said cells to compress the same upon relative pivotal movement between said members, a check valve in said partition to permit inflating uid to flow freely from said one cell to the other cell, and a restricted passage between said cells to permit inflating iiuid to ow, at a low rate from said other cell to said one cell.

2. In an artificial limb, a pair of members, joint means providing for relative pivotal movement between said members, each of said members comprising a hollow shell, an inflatable bag in said hollow shells and extending across said joint, and means actuated by relative pivotal movement of said members to compress a portion of said bag, said means being xedly carried by one member and extending across said joint to engage said bag in the other of said members whereby tc urge said members in relative pivotal movement opposite to that effecting compression of said bag by return of said Abag to uncompressed condition.

3. In an articial limb, a pair of members, means providing for relative pivotal movement between said members at a limb joint, each of said members comprising a hollow shell, and an inflatable bag within said hollow shells and extending across said joint.

4. In an articial limb, a pair of members, means providing for relative pivotal movement between said members at a limb joint, each of said members comprising a hollow shell, and an inflatable bag within said hollow shells and extending across said joint, said bag having a restricted flexible neck portion at said joint.

5. In an artificial limb, a pair of members, means providing for relative pivotal movement between said members at a limb joint, each of said members comprising a hollow shell, and an inflatable bag within said hollow shells and extending across said joint, said bag having a restricted flexible neck portion at said joint, portions of said bag adjacent to and on opposite sides of said neck portion being relatively inflexible and normally in contact with each other.

6. In an artificial limb, a foot section and a leg section, said sections comprising hollow shells, an opening in said foot section at the ankle thereof, said leg section having a terminal portion at the bottom thereof within the said opening, an inflatable bag within said shells and extending across said ankle joint, said leg sec- 7; tion resting upon-and being at .least partially supported by a vportionlof said inatable bag in said foot section.

7. An artificial limb as defined in claim 6 and further including a helical spring loosely surrounding the lower portion of said leg section, said spring bearing upon an upper surface of said foot section and engaging said leg section to at least partially support said leg section.

8. An artificialllimb as defined in claim 6 wherein said leg section is provided with an abutment normally spaced above said foot section but engageable therewith to limit downward movement of said leg section relative to said foot section.

9. An artificial limb as defined in claim 6 wherein said leg section is provided with an abutment normally spaced above. said foot section but engageable therewith Vto limit downward movement of said leg section relative to said foot section, said abutment being positioned at the side of said leg section, and said foot section having a curved surface engageable with said abutment whereby said leg section may rock in a ,fore and aft direction relative to said foot section while in its lowermost position.

10. In an `artificial limb, an upper section, a lower section, said sections being pivotally joined on a transverse axis to provide a joint, said sections further having relatively 'slidable overlapping portions on one side of said axis, and a pad of resilient material overlying said overlapping portion.

11. An articial limb as defined in claim l0 wherein said pad is fixed to at least one of said sections adjacent said overlapping portions.

l2. In an artificial limb, a pair of members, joint means providing for relative pivotal movement between said members, said members each comprising a hollow shell, an inflatable bag in said hollow shell and extending across said joint, one of said members having a portion engaging said inatable bag to compress the same upon relative pivotal movement between said members.

REX R.. HYDORN.

REFERENCES CITED g The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 598,452 Tullis Feb. 1, 1898 708,685 White Sept. 9, 1902 2,416,817 Carter Mar. 4, 1947

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