US2657393A - Fluid-cushioned artificial leg - Google Patents

Description

Nov. 3, 1953 J. HALLER 2,657,393

FLUID-CUSHION@ ARTIFICIAL LEG Filed June 21, 1952 2 sheets-sheet 1 :inventor C orneg NOV. 3, 1953 J. HALLER l 2,657,393

FLUID-CUSHIONED ARTIFICIAL LEG Buncnfor ornegs Patented Nov. 3, 1953 UN ITED STATES FF l 2,657,383

FLUID-CUSHIONED ARTIFICIAL LEG` John 'Haller2 Northville, Mich. Application .lune 21, 1952, Serial N o. 234,821

8 Claims. 1

This invention relates :to articial limbs and. in particular, to artificial legs.

One object of this invention is to provide a fluidecushioned artificial leg enabling the wearer to obtain a smooth vand even heel andtoe ac tion ofthe foot together with a desired amount of resistance to such action, this resistance being adjustable to provide a stiff action vfor a heavy person or alight action for a lightweight Person.

Anothervobject is to provide a fluid-.cushioned artificial leg of .the 'foregoing character, wherein the cushioning :action Ais brought about tby the reciprocation of a piston Within the ankle portion of the artiiicial leg in response to the rocking of the foot portion, the flow of lludresulting from the reciprocation of ythe piston being controlled'by an adjustable resistance'rnember, such as a spring-pressed valve which yieldingly opposes the free vflow of such fluid with a predetermined resistance.

Another object is to provide a .fluid.cushioned artificial leg of the foregoing character wherein the -reciprocating piston is also yieldingly opposed, as by a compression spring which returns the piston to its starting point when the foot rocks hack to its neutral position between 'the extreme forwardvand rearward portions of the stride.

Other objects and advantages of the invention will :become apparent during the course oi the following description of the accompanying drawings, wherein:

Figure 1 is a side elevation, mainly in `central vertical section, of the lower portion of afinidcushioned articial leg Vin its neutral position according to one Aform of theinvention;

Figure 2 is a .horizontal lsection taken along the line 2--2in Figure 1;

Figure 3 is a view similar tUFigure. lfbut show ing the positions of the parts when the f oot is at the forward end of its vforward Stride; and

Figure 4 is an enlarged fragmentary view of one of the ball check valves vof Figure 1, Asljlowing the bypass grooves therein.

Referring to the drawings in detail, Figure l shows a duid-cushioned artificial leg, generally designated Ill, the upper portion being of iconventional construction, particularly as regards its means of attachment .to the stump of the living leg remaining after amputation. The articialleg I is provided with a fluid-operated cushioning device, generally `designated I I, mounted in the ankle portion I2 of the leg Il) to which the foot portion, generally designated I3, is pivoted, as at thepivot yjoint I4.

The foot. portion 1.3, is shaped like e. human fooi, lso as to maten :the weareris other 4foot in sizeand shape, except that a wedge-shapedeleorance is provided between the iorward and yFedra Ward portions or toev `and heel porti, s l5. and i6. by providing wedge-shaped cops between the upper flat surfaces Il and I8 of the lroet pore tion I3. and the lower flat surfaces I3 and 2Q of the ankle portion I2.V The portions II and I8 are inclined at olotoseonele to one oriother as .are the ankle portions i9 and 2U, in order to. provide these Wedge-.Shaped Clearance spaces l2l and 22 facilitating vnormal striling or walking motion by permitting lrookins of; the foot portion I?. relatively te the ookle portion I2 around the pivot joint I4.

The pivot joint Ii consists of e peil oi aligned vertical bores 25 and 26 in the foot and ankle portions I3 and I2 respectively, these receivingbali and socketloolts. 2l and 2 8 respeotivelv- The ball bolt 21 is anchored in `position by a nut 2Sl mounted in e ooontersnk 3l! and provided with wrench or spanner holes 3l by which its threaded bore '3 2 is threaded upon the threaded portion as of the toit 21. The upper end 0f the bore 2 5 terminates a spherical clearance lrecess 35 above which the ball head 36 of the ball .bolt 2l projects.

The ball hood 3691s, Provided with a spherical convex surface il which is Seated in a correspending spherical concave surface 38 provided in a hollow spheriool shell portion 3Sy on the. lower end of the socket bolt 28. The outer suriace 40 of the spherical shell 39 has a Spherical curvature concentric with the curvature of the surfaoes 3,'I, 38 and 35 and closely fitting the spherical surface 35 inthe rocking action of the fcot portion I3. relatively tothe ankle portion IZ. The shell portion 39 is seated Vinra spherical socket 4I in the lower end of the anklefportion I2 whereas lthe `upper end of the socket bolt 28 threaded as yat Yd2 to receive a retaining nut 43 and .passes Vthrough a hole 44 in the lower end or head d5 of a fluid cylinder 46.

The upper suriaoes I1 Iend I8 of the toot portion I-3 are provided with cup-shaped, sockets 50 and 5I vrespedilvely reoeivinehardened metal Contact plugs or -lodttons 52 ond 53 respectively located at' short distances from the center del of the ball head 3.6; Engaging theoontaot but: tons 52 dhd53 are the rounded lower ends 5,5 and 56 respectively of reoiproooble metiera-trans,- mittine rods 5l and 58 reoiprooablv mounted in bores 5S Vand BIJ located Yvvithrtheir axes parallel to and spaoed eouidistontly from the exis of the socket bolt Zd. The vrods 5l `and 58 pass actress l. 3 through holes 6| and 62 in the cylinder head 45 aligned with the bores 59 and 60.

The fluid cylinder 46 is mounted in a cylindrical socket or bore 65 opening into a hollow 55 within the upper part of the ankle portion 12, and is provided with an outer cylinder bore l|51, the upper end of which is threaded as at 68 and closed by a threaded plug or head 69 threaded therein as at and provided with wrench or spanner sockets 1|. On its underside, the head 69 is provided with a cylindrical recess 12 receiving a spring abutment collar 13 of similar conguration and having a central bore 14 opening into a counterbore in its upper end. Passing through the bore 14 and having its upper end seated in a coaxial counter-bore 16 in the cylinder head or plug B9 is a hollow tubular stem 11 having an annular recess 18 near its upper end engaged by a snap ring 19 mounted in the counterbore 15. The spring abutment collar 13 is provided with a reduced diameter portion 80 having a surrounding annular shoulder 8| which serves as an abutment for the upper end of a helical compression spring 82.

The lower end of the compression spring B2 engages an annular abutment shoulder 95 on a closure head 86 which is provided with a threaded portion 81 :by which it is threaded into the correspondingly threaded portion 88 at the upper end of an inner cylinder bore 99 within a hollow piston 90 reciprocably mounted within the outer cylinder bore 61. A gasket 9| of yieldable material, such as rubber or synthetic rubber, prevents fluid leakage and provides resilience at this location. The midportion of the tubular stem 11 passes through a bore 92 in the closure head 88 of the hollow piston 90 and emerges within the inner cylinder bore 89 where it is provided with an enlargement 93 having an annular abutment surface 94 beneathwhich the stem 11 is provided with an extension 95. The closure head 86 of the piston 90 is provided with an annular recess 95 receiving a so-called O-ring 91 of elastic deformable material such as rubber or synthetic rubber and this is held in position by a retaining ring 98 mounted in a recess 99 by means of screws |90.

Mounted on the extension 95 of the hollow or tubular stem 11 is an annular stationary inner piston head |0| with its upper end |02 engaging the abutment shoulder 94 and with its midportion provided with an annular recess 103 also receiving an O-ring |04 of elastic deformable material such as natural or synthetic rubber, in order to prevent fluid leakage between the piston 90 and cylinder 45. The piston head |01 is held in position by a snap ring |05 seated in an annular recess |06 in the lower end of the stem extension 95 and engaging a port ring |01 provided with a plurality of circumferentially-spaced lower uid ports |08 (one only being shown). The port ring |01 is secured in an annular recess |09 in the lower end of the inner piston head |0| by means of screws ||0.

Immediately above the ports 108, the inner piston head |0| is provided with a corresponding number of cylindrical ball valve chambers'Hl, each of which contains a vertically reciprocable ball check valve member |12. The ball check valve members 112 are movable upward against seats consisting of the lower ends of upper uid ports 113 which extend from the upper ends of the ball valve chambers |11 into radial half-teardrop-shaped fluid passages ||4 leading past the annular abutment surface 94 into the upper end of the inner cylinder bore 4 89. The upper ends of the lower uid ports |08 are prevented from being closed by the balls |12 by the provision of bypass grooves 109e formed therein.

Extending upward through the tubular stem extension 95 from the lower part of the inner cylinder bore B9 is a central fluid passageway l5, the upper end of which serves as a ball valve seat in an enlarged vbore |19, the lower portion of which is smooth and the upper portion threaded. Running from the ball chamber |15 radially through the stem Y enlargement 93 to the upper portion of the inner cylinder bore 89 is a fluid passageway |11. Reciprocably mounted in the lower end of the enlarged bore H8 is a ball check Valve member |18 which is urged downwardly by a headed pin |19 which itself is urged downwardly by a helical compression spring |20 mounted in the hollow stem bore H5. The upper end of the spring 120 abuts against the lower end of a screw plug 12| threaded into the threaded upper portion of the bore |19, and adjustable by means of an ordinary screw driver.

The upper end of the stem bore |16 is closed by a screw plug |22 threaded into the upper end thereof and having its head seated in a recess |23 in the cylinder head 09. Thus the screw |22 also holds the tubular stem 11 within the counterbore 15. A fluid passageway or bleeder hole |28 extends obliquely upward from the space above the piston head 10| within the stem enlargement 93 into the portion of the stem bore w |16 above the spring abutment pin |19 to release duid leaking past the pin |19.

The inner piston head |0| and the stem enlargement 93 are made in two pieces in order to provide convenient machining of the passageways 1M. It is possible, however, to form the `head |0|'integral with the stem enlargement 93 by rendering this machining operation somewhat more complicated.

In the operation of the invention, let it be assumed that the leg 10 is strapped or otherwise attached by conventional means (not shown) to the stump of the amputated leg and is, of course, of suflicient length for that purpose. By previously having removed the sealing plug |22 from the upper end of the bore 1 16 within the tubular stem 11, the adjusting screw |21 is screwed upward or downward to increase or decrease the force exerted by the helical spring |20 upon the contact pin |19 which engages the ball check valve IIB, until the desired resistance is obtained to Y the flow of fluid upward through the passageway.

Let it be assumed that the wearer thrusts his leg forward to begin to walk, placing his weight upon the heel portion I8 of the foot 13. This action (Figure 3) causes the foot 13 to rock about the pivot joint 14, forcing the motion-transmitting rod 53 upward and consequently pushing the hollow piston upward in the cylinder bore 81, toward the stationary inner piston 10 compressing the spring 82. The fluid trapped below the piston head |0| is forced upward through the passageway 1 I5, raising the ball check valve |18 oil its seat at the upper end of the passageway ||5 and thereby overcoming the thrust of the spring |20 and compressing it (Figure 3). This permits the fluid to pass from the passageway ||5 through the passageway ||1 into the upper end of the inner cylinder bore 89. As the passageways |15 and |11 are constricted, the action is cushioned by the spurting of the iluid, such as oil, through these constricted passageways ||5 and |11. Meanwhile, the ball check valve 5 't #-2 hasfrisen, havin'g'beenv forcedl upwar'dby f iluid passing through the `passageways TI'8 into the chamber lfllfcausing fthe ball H2 'to -seal the lower-*ends of the passageways fl |`3 (Figure 3).

JlAs-"thefoot f3 rocks about the pivot `joint Vi4 during the-completion of the'stride, the-'rearward piston rod 'i5'8 iis lpushed downward -in response to 'the pushing 4downward of the hollow piston S'Oibythecompression spring 82 and "fluid passes from ftheupper partof the1innerbore`89 to the lower part'thereof by way Vof the radial passage- Ways llfdand vthe passageways H3 and |08 past the ball valves |I`2. After the foot passes vthe neutral for mid-stride vposition (Figure l), the rodliljis pushed upward, again' pushing l the -hollow'lpi's'tonlwupward and compressing the spring 82 while again forcing the ball rcheck valve H8 off its seat in compressing its spring I20,'again releasing fluid to pass through the passageways H5 and III into the upper part of the inner cylinder bore 89 in the same manner as described in connection with Figure 3. This again exerts a. cushioning action in the same way as described above. When the walker reaches the rearward end of his stride and starts forward again, the foot I3 again rocks through the neutral position of Figure 1 to the forward position of Figure 3, repeating the foregoing operations.

What I claim is:

l. A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston fixedly mounted in said inner cylinder bore, said stationary piston having a restricted forward fluid passageway and a return fluid passageway therethrough, and a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder.

2. A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston xedly mounted in said inner cylinder bore, said stationary piston having a forward fluid passageway and a return fluid passageway therethrough, a one-way valve disposed in one of said passageways permitting only unidirectional uid ilow therethrough, and a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder.

3. A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston flxedly mounted in said inner cylinder bore, said stationary piston having a forward fluid passageway and a return fluid passageway therethrough, a one-Way valve disposed in each of said passages. ways VIpermitting only unidirectional -fluid'fow therethrough, anda motion-transmittingI element extending from-'said foot member throughlfs'aid cylinder to' saidfmovable'piston` and responsiveto the rocking of said-foot memberfor reciprocating said'movable piston in said cylinder.

4. A 'duid-cushioned?articial leg comprising a-leg member, 'a 'foot'member pivotallyl attached to--saidlegmember for rocking motionrelatively thereto, alfluidfcylinder-mounted in one "of said members and having an outer cylinder bore therealhollow 'movable' piston reciprocablymounted in said outercylinder'bore and having lain-inner cylinder bore therein, -a stationary piston fflxedly mounted linsaidinner cylinder bore, said-'stationary piston lhaving* aforward fluid 'passageway and fa return 'fluid passageway therethrough-a one-way valvefdisposediin each 'o'f said passageways permitting only unidirectional fluid flow therethrough, a resilient element engaging and yieldingly urging one of said valves into its closed position, and a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder.

5. A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston fixedly mounted in said inner cylinder bore, said stationary piston having a restricted forward fluid passageway and a return fluid passageway therethrough, and a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder, and a resilient member yieldingly engaging and urging said piston against said motion-transmitting element.

6. A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston flxedly mounted in said inner cylinder bore, said stat1onary piston having a forward fluid passageway and a, return fluid passageway therethrough, a one-way valve disposed in one of said passageways permitting only unidirectional fluid ow therethrough, a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder, and a resilient member yieldingly engaging and urging said piston against said motion-transmitting element.

7 A fluid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a fluid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having' an inner cylinder bore therein, a stationary piston xedly mounted in said inner cylinder bore, said stationary piston having a forward fluid passage.

Way and a return uid passageway therethrough, a one-way valve disposed in each of said passage- Ways permitting only unidirectional fluid flow therethrough, a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder, and a resilient member yieldingly engaging and urging said piston against said motion-transmitting element.

8. A huid-cushioned artificial leg comprising a leg member, a foot member pivotally attached to said leg member for rocking motion relatively thereto, a uid cylinder mounted in one of said members and having an outer cylinder bore therein, a hollow movable piston reciprocably mounted in said outer cylinder bore and having an inner cylinder bore therein, a stationary piston fixedly mounted in said inner cylinder bore, said stationary piston having a forward fluid passageway and a return fluid passageway therethrough, a one- Way valve disposed in each of said passageways permitting only unidirectional fluid flow therethrough, a resilient element engaging and yieldingly urging one of said valves into its closed position, a motion-transmitting element extending from said foot member through said cylinder to said movable piston and responsive to the rocking of said foot member for reciprocating said movable piston in said cylinder, and a resilient member yieldingly engaging and urging said piston against said motion-transmitting element.

JOHN I-IALLER.

No references cited.

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