US2305291A - Device for the automatic control of the articulation of the knee applicable to a prothesis of the thigh - Google Patents

Description

DC. l5, 1942 P.. FILIPPI DEVICE FOR THE AUTOMATIC CONTROL OF THE A OF THE KNEE APPLICABLE TO A ROTHESIS OF TH Filed June 24, 1937 1 1 9 .t 2, 5 h o Q v 3,9m 216e. TIe Hh LTS U CE2 I T R SMM/M5 DEVICE FOR THE AUTOMATIC CONTROL OF THE ARTICULATION OF THE KNEE APPLICABLE TO A PROTHESIS OF THE THIGH Filed June 24, 1937 '2 Sheets-Sheet, 2

Patented Dec. 15, 1942 DEVICE FOB THE AUTOMATIC CONTROL 0F THE ARTICULATION OF THE KNEE AP- PLICABLE TO A PROTHESIS 0F THE 'mien Pietro Filippi, Macerata, Italy; vested in the Alien Property Custodian Application June 24, 1937, Serial No. 150,176 In Italy April 3, 1937 9 Claims.

This invention relates to a device for the automatic control of the articulation of a joint in an artiilcial limb, and more particularly to suchdevices as are applicable to a knee `joint in a prothesis of the thigh.

The general object of the invention is to provide a novel and improved device of this character which is of simple and compact construction, light in weight, and easily and automatically operative by the natural movements and postures of the body.

Another object of the invention is to provide in a device of this type, mechanism which will permit the knee joint full freedom of movement when desired, but is capable of being blocked either deliberately or automatically (as when balance of posture has to be regained in walking)I and then released for permitting ilection of the joint after the limb is extended.

Further objects of the invention include the provision of an extensible and contractible hydraulic system associated with they joint of the prothesis and adapted to be blocked and released by means of a tension member attached to the torso of the wearer and responsive to certain deliberate and involuntary movements of the body. 1

In its preferred form, the invention contemplates theprovision of a hydraulic cylinder having a piston working therein, one of these elements being connected to the lower leg portion of the prothesis and the other to the upper leg portion or thigh. .Valves are provided in the piston member to permit the by-passing of hydraulic uid, and the actuation of certain of these valves is effected by a tension member which operatively connects a movable portion of the piston with a belt forming part of the harness for attaching the limb to the wearer so that when he leans forwardly, either deliberately or instinctively (as in regaining his balance lost by placing his foot on the ground with the knee bent), or when he lifts the thigh upwardly, the

` connecting tension member actuates the valve to block the contraction of the system. On the other hand, further extension of the joint is permitted by another valve which is of the one-way or check valve type. f

Other and further objects and features of novelty will be apparent from the following speciii- I cation when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by way of example.

In the drawings: l'

Figure 1 is a vertical cross-sectional view of i the apparatus proper which is preferably disposed inside ot the lower leg portion of the artiilcial limb; the parts being in the position affording the knee joint full freedom of movement;

Figure 2 is a fragmentary view similar to Fisure 1 with the parts in 4position to prevent the flection of the articulation;

Figure 3 is a similar view showing the parts in position as when extension of the hydraulicv device begins;

Figure 4 is a view in side elevation of the whole artiileial limb when raised as high as possible;

Figure 5 is a similar view showing the leg in vertical position; and

Figure 6 is a view also in side elevation showing the limb bent. A

The prothesis or articial limb may be of any suitable form and is somewhat diagrammatically shown in Figures 4, 5 and 6 as comprising the upper leg or thigh portion I4 and the lower leg portion 3 hinged together to provide an articulated knee joint indicated at 3'. The limb is attached to the torso of the wearer by a suitable harness which includes the belt 23.

The novel means for controlling the articulation of the joint 3' comprises the hydraulic cylinder I which is closed at its lower end by the plug 2 which is secured as by means of the ring 2 to the lower portion of the lower leg member 3. The cylinder is provided at its upper end with a bushing 4 provided with a leather packing ring 5 and stufdng box arrangement 6 through which a piston rod is adapted to pass. the cylinder I there is adapted to reciprocate the piston 1 to which there is threaded as at 1' the tubular piston rod 8 which extends through the packed opening at the upper end of the cylinder and is attached to the bifurcated element I2 carried by the pivot pin I3 which is connected to the base of the thigh portion I4 of the limb. A nut I5 serves to vary the connection between the tubular piston rod Il and the member I2 in order to adjust the degree oi' opening of a control valve as will be later described. -A leather packing ring I0 and bushing II provide altight fit for the piston 1 in the bore .of the cylinder I.

The hollow tubular pistnnrod 8 encloses a rod or shaft 9 which carries at its lower end a valve assembly for controlling the by-passing of the hydraulic fluid. At the upper end of this shaft 9 there is secured a block or bracket 2| to which is attached the cable 22 forming a part of the tension member by which the valve is operated. The cable 22 passes around the pulley I9 carried Within.

by an arm I2' provided on the member I2. The cable 22 forms an inelastic portion oi' the tension member which also comprises the elastic part 22' the upper end of which is adjustably attached to the belt 23 in any suitable manner as at 2l; the inelastic portion 22 of the tension member extending along the thigh I4 and the elastic portion passing over the rear portion of the hips to its point of attachment to the belt.

At the lower end of the shaft 9 which extends through the tubular piston rod 8, a conical valve 25 is mounted, the valve being provided with a series of openings 26. The valve 25 is adapted to seat against the conical surface of the annular base portion 21 of the piston and thus control the passage of fluid through the passageways 21', the interior chamber 29 and the upper series of passageways 28 all providing communication between the upper iluid chamber portion I1 and the lower portion I9. In Figure 1 the valve 25 is shown in the open position which it occupies during ection of the knee joint. Beneath the valve 25 there is provided a flexible valve 30 which is preferably faced with leather and is supported by the washer 3| carried by the end of the valve stem or shaft 9. This washer 3| is also provided with a series of openings 32. A spring 33 which is disposed between the upper portion of the piston 1 and an abutment 33 carried by the shaft 9, serves to continually urge the valve 25 downwardly toward open position. By a suitable adjustment of the nut I5 the lowermost position of the block 2|, and thus the lower portion of the rod 9, are determined and thus the width of the opening I6 aorded by the valve 25 may be varied.

The operation of the controlling device will now be described in connection with thel three typical positions illustrated in Figures 1, 2 and 3 of the drawings. In the iirst position, shown in Figure l, the valve 25 is open and the hydraulic iiuid may iiow freely through the valve opening I9 and the passageways and chambers 21', 2B, and 29 to and from the upper and lower iluid chambers l1 and I8; in other words, the piston 1 is permitted to slide within the pump cylinder and allow the free articulation of the knee joint in either a iiection or extension direction.

In Figure 2, the device vis shown wherein the valves 25 and 30 have been closed by the upward movement of the shaft 9 under the iniluence of the tension member 22, 22'. In this position the fluid can no longer ow through the by-pass pas- 'sageways in the piston 1 and contraction of the hydraulic system connecting the portions of the limb is prevented. Consequently ilection of the knee joint is also prevented, as for example when the limb is bent as shown in Figure 6. The wearer may thus rest his whole weight upon the artificial limb while lifting the other foot to take a step.

In' the position illustrated in Figure 3, the valve 25 remains closed, but the ilap valve 30 is opened as the knee is stretched or extended, the piston 1 moving upwardly and the hydraulic iiuid ilowing from the upper chamber I1 to the lower chamber I8 through the openings 26 in the main valve body member 25. Thus, the limb which is still in the blocked position as respects f lustrated in Figure 2.

Tension in the valve actuating member 22, 22' results when the body leans forward or when the thigh is lifted, the elastic portion 22 being extended and the inelastic part 22 drawn tight. As already mentioned, the body may lean forward voluntarily and deliberately, or involun l tarily as in response to the spontaneous reaction engendered by loss of balance through insumcient support upon the foot of the prothesis.

The oil or other hydraulic iluid should not occupy the whole of the space inside the cylinder I but the level should remain slightly below the bushing l in order to leave a layer of air in the upper portion of the chamber I1 by means of which lthe displacement of the piston 1 is kept more elastic and the leakage of oil between the rod 8 and the packing 5, B is rendered more diilicult.

The device may be made of any suitable materials but it is suggested that the cylinder and its closures may be made of steel and the piston 1 may be constructed o f aluminum.

It is understood that various changes and modifications may be made in the device as illustrated and described herein without departing from the scope of the invention as determined by the subjoined claims.

Having thus described the invention, what is claimed as new and4 desired to be secured by Letters Patent is:

l. The combination with an artificial limb having at least two articulated members and means for attaching the limb to the wearers body, of a device for the automatic control of the joint between said articulated members, said device comprising an extensible and contractible hydraulic system including a cylinder pivotally connected to one of said members and a piston working in the hydraulic iluid contained in the cylinder and connected with another of said members, a multiple by-pass valve assembly disposed in said hydraulic system and controlling the iiow o1' iluid from one side of said piston to the other, and valve operating means adapted to be connected to the torso of the wearer so as to be automatically and positively actuated by the natural fiection of the torso to operate said valve assembly to prevent flow of iluid from one side of the piston to the other to prevent contraction of the system and consequently prevent flection of the joint, said multiple valve assembly being automatically operative upon movement of the piston in a direction to extend said system to permit ow in the opposite direction to allow further extension of the joint.

2. The combination with an articial limb having at least two articulated members and means for attaclflng the limb to the wearers body, of a device for the automatic control oi' the joint between said articulated members, said device comprising an extensible and contractible hydraulic system including a cylinder pivotally connected to one of said members and a piston working in the hydraulic uid contained in the cylinder and connected with another of said members, and a by-pass valve on said piston and controlling the iiow of iluid from one side of the piston to the other, said attaching means including a portion adapted to be applied to the torso of the wearer, means associated with said attaching means and adapted to be operated by iiection of the torso, said means also being connected with said bil-Dass valve to actuate the latter to block the contraction of the hydraulic system and thus prevent flection of the joint.

3. A device as set forth in claim 2 in which contraction of the system is prevented by saidv first named valve.

4. The combination with an artificial limb having at least two articulated members and means for attaching the limb to the wearers body, of

a device for the automatic control of the joint between said articulated members, said device comprising an extensible and contractible hydraulic system including a cylinder pivotally connected to one of said members and a piston working in the hydraulic fluid contained in the cylinder and connected with another of said members` and provided with an opening therethrough, a main valve member carried by said piston, means adapted to be connected with the torso of the wearer and responsive to the changes in posture for causing said valve member to close said opening and prevent contraction of the system, said valve member also being provided with an opening controlled by a supplemental flap valve adapted to permit flow in one direction to allow further extension of the system even lwhen the main valve member is closed.

5. The combination with an artificial limb having at least two `articulated members and means including a belt for attaching the limb to the wearers body, of a device for the automatic control of the joint between said articulated members, said device comprising an extensible and contractible hydraulic system including a cylinder pivotally connected to one of said members and a piston working in the hydraulic fluid contained in the cylinder and connected with another of said members, and a by-pass valve on said piston and controlling the ilow of iiuid from one side vof the piston to the other, an elasti'c tension member adapted to extend along the thigh and hips and connecting said by-pass valve with said belt, whereby upon occurrence of certain changes in posture of the wearers body, said system is blockedand collapsing flection of the joint prevented.

6. A device as set forth in claim 2 in which the cylinder of said hydraulic system is only partially full of the hydraulic fluid, a layer of air remaining above the level of the uid for imparting a certain amount of elasticity to the system.

'7. The combination with an artificiallimb having at least two articulated members and means including a belt for attaching the limb to the wearers body, of a device for the automatic control of the joint between said articulated members, said device comprising an extensible and contractible hydraulic system including a cylinder pivotally connected to one of said members and a piston working in the hydraulic fluid contained in the cylinder, a tubular piston rod extending through packing at one end of the cylinder and connected with another of said members, a by-pass passageway leading through said piston, a main by-pass valve controlling the passage of hydraulic fluid through said passageway from one side of the piston to the other, a valve stem adapted to support said valve and extending through said tubular piston rod, a tension member secured to one end of said stem and operatively connecting the valve to the belt of the wearer, said main by-pass Valve being provided with openings therethrough, a flap main by-pass valve carried by said main valve and adapted to control the flow of hydraulic fluid through the openings in said main Icy-pass valve in one direction only.

8. An artificial limb including upper and lower members hingedly connected, a plunger mounted for reciprocation in one 'of the members, means carried by the other member for reciprocating the plunger when one member is swung relativeto the other, an incompressible fluid in the path of the plunger, a valve, and means cont r olled by the movement of the artificial limb relative to the body to which it is attached, for opening and' closing the valve to release or to trap the fluid in the path of the plunger.

9. In an articial limb the lcombination with hingedly connected members, a plunger mounted to reciprocate in one of the members, and cooperating means on the other member and plunger for reciprocating said plunger when the members are swung relative to each other, of a liquid in the path of the plunger, means for attaching one of the members to the body of the user for swinging movement, and means controlled by the swinging movement of the limb relative to the body of the user for successively trapping and releasing the uid to lock and unlock the plunger respectively.

- PIETRO FILIPPI.

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