Source: https://patents.google.com/patent/EP0503775A1/en
Timestamp: 2019-02-17 22:19:16
Document Index: 535444742

Matched Legal Cases: ['art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'art 10', 'arts 10']

EP0503775A1 - An artificial leg - Google Patents
An artificial leg Download PDF
EP0503775A1
EP0503775A1 EP19920301254 EP92301254A EP0503775A1 EP 0503775 A1 EP0503775 A1 EP 0503775A1 EP 19920301254 EP19920301254 EP 19920301254 EP 92301254 A EP92301254 A EP 92301254A EP 0503775 A1 EP0503775 A1 EP 0503775A1
EP19920301254
John Jeffrey Shorter
Victor James Woolnough
Peter Dan Edwards
1991-03-14 Priority to GB919105464A priority Critical patent/GB9105464D0/en
1991-03-14 Priority to GB9105464 priority
1991-10-09 Priority to GB9121417A priority patent/GB2253791B/en
1991-10-09 Priority to GB9121417 priority
1992-02-17 Application filed by Chas A Blatchford and Sons Ltd filed Critical Chas A Blatchford and Sons Ltd
1992-09-16 Publication of EP0503775A1 publication Critical patent/EP0503775A1/en
An artificial leg includes a knee mechanism having means for restricting knee flexing movement during the stance phase of the walking cycle. The restricting means includes a piston (30) and cylinder assembly (28) so coupled in the mechanism that the piston is movable in the cylinder with knee flexion and extension. The knee mechanism includes two chassis parts (10A,10B) arranged to move relatively to each other when an axial load is applied to the limb. One end of the piston and cylinder assembly is connected to one of the chassis parts (10B) while the other chassis part (10A) engages a control member (38) coupled to a valve (40) inside the piston and cylinder assembly so that the valve is operated in response to relative load-dependent movements of the chassis parts in order to restrict the flow of fluid and thereby create resistance to knee flexion during the stance phase. The chassis parts are connected together by an anterior pivot joint (16) and are resiliently moveable relative to each other according to applied load. The piston and cylinder assembly is also operable to resist movement during the swing phase of the walking cycle, and the interaction of the knee chassis parts with the control member is arranged so that movement of the member is reduced or does not occur at all for flexion angles greater than a predetermined value between 30° and 40°.
According to one aspect of this invention there is provided an artificial leg which has an upper leg component; a lower leg component; knee pivoting means pivotally coupling the lower leg component to the upper leg component to permit knee flexion and extension movements; an hydraulic piston and cylinder assembly coupled between the upper and lower leg components to resist at least the flexion movement during the stance phase; and automatic control means for altering the degree to which the piston and cylinder assembly resist the flexion movement; wherein one of the leg components includes at least two portions, one of which is coupled to the other leg component by the knee pivoting means and is movable relative to the other of the two portions in response to application of an axial load to the one leg component; and wherein the control means are responsive to the relative movement of the leg component portions to increase the resistance of the piston and cylinder assembly to the flexion movement when the knee flexion angle is within a first knee flexion angle range, but are unresponsive or responsive to a lesser degree when the knee flexion angle is within a second knee flexion angle range which is above the first angle range. In this way, knee stability can be obtained with an hydraulic device, to the extent of an hydraulic lock if required, automatically when the patient applies weight during the stance phase. No conscious knee-extending movement needs to be made when resistance to flexion is to be removed, and stance control is available during the initial part of the flexion range when it is needed. Preferably little or no increase in resistance to knee flexion occurs when the knee flexion angle is within the second knee flexion angle range.
Figure 1 is a partly sectioned side elevation of part of an artificial leg in accordance with the invention;
Figure 2 is a rear elevation of part of a knee mechanism shown in Figure 1;
Figure 3 is side elevation of an upper chassis part of the mechanism;
Figure 4 is an underside view of the upper chassis part section on the line A-A in Figure 3;
Figure 5 is a partly sectioned side view of a lower chassis part of the knee mechanism;
Figure 6 is an underside view of the lower chassis part sectioned on the line B-B in Figure 5;
Figure 7 is a detail of a piston rod end;
Figure 8 is a diagram depicting different phases of resistance to knee flexion and extension movements;
Figure 9 is a side elevation of the knee mechanism shown in Figure 1, the mechanism being in a loaded condition.
Referring to Figures 1 to 7, an artificial leg in accordance with the invention has a knee mechanism with a knee chassis 10 having an upper part 10A for connection to an thigh component 12 and a lower part 10B for connection to a shin 14, which are pivotally connected to each other by a transverse front pivot pin 16 housed in two ears 10AE of the upper part 10A and passing through a bore in a front end portion 10BF of the lower part 10B. The lower chassis part 10B extends rearwardly from the front pivot pin 16 to a rear portion 10BR which carries a stack of disc springs 18 on an upright stud 20. This stud 20 has an upper end 20A (Figure 5) which projects beyond the spring stack 18 and is received in a bore 22 (Figure 4) in the upper chassis part 10A. Rearwardly of the spring stack 18, the lower chassis part rear portion is divided into two lugs 10BL each bored to accept a rear pivot pin 24. Adjacent the inner faces of the lugs 10BL are two cam plates 10AC depending from the upper chassis part 10A which is contiguous and overlapping with respect to the lower chassis part 10B. It will be seen that the lower chassis part 10B is free to pivot on the front pivot pin 16 subject to the resistance provided by the spring stack 18 bearing against the underside of the upper chassis part, with the lugs 10BL moving up or down relative to the cam plates 10AC. An aperture 10AA (Figure 3) is cut in each cam plate 10AC to allow sufficient clearance around the rear pivot pin 24 for such movement. A front nose portion 10BN of the lower chassis part 10B extends forwardly of the front pivot pin 16 and has an upper stop surface 10BS which is positioned so as to bear against a lower stop surface 10AS of the upper chassis part 10 to limit the extent to which the two chassis parts can move apart.
As the knee flexes, the piston 30 moves downwardly in the cylinder body 28. When the amputee applies weight to the leg, a longitudinally directed force on the shin 14 is applied to the knee axis bearing pin 36, causing the lower chassis part 10B to move towards the upper chassis part 10A provided that the force is sufficient that the spring stack 18 can be compressed. As a result the upper end of the piston rod 32, secured to the rear pivot pin 20, moves upwardly between the cam plates 10AC. The piston rod 32 houses a slidable coaxial control rod 38 acting as a valve control member for a valve 40 housed in the main piston 30.
The upper end of the control rod 38 carries a cross pin 38A which penetrates the wall of the piston rod 32 through slots 42 to emerge on both sides adjacent cam surfaces 10CS of the cam plates 10AC. In fact, a spring 44 inside the piston rod 32 biases the control rod 38 upwardly into contact with the cam surfaces 10CS so that as the knee flexes the pin 38A follows the cam surfaces providing it does not reach the ends of the slots 42. It will now be understood that upward movement of the lower chassis part 10B due to application of the amputee's weight causes downward movement of the control rod 38 with respect to the piston 30. A valve member 40A secured to the lower end of the control rod 38 is arranged to close off progressively passages 30P connecting one side of the piston 30 to the other as the control rod 38 moves downwardly in the piston rod 32, thereby restricting fluid flow through the piston 30 to the extent that, when the valve 40 is fully closed, an hydraulic lock results, thereby locking the knee.
During the initiation of flexion prior to toe-off, the stance control resistance, i.e. the hydraulic lock, is normally progressively removed as weight is transferred to the other leg. This normally occurs well below the 35° flexion angle referred to above. To avoid any unwanted hindering of such removal of stance control due to forces generated by the secondary piston 46, the function of which is swing control, a passage 56 opens out into the upper part of the wall of the cylinder 48 to provide a large orifice area at the beginning of the downward stroke of the piston 46. The passage 56 links the cylinder space below the piston 46 to the space above the piston either directly, as shown in figure 1, or via a non-return value if cushioning towards the end of the extension stroke is to be retained. As a result, the resistance to flexion provided by the piston 46 during the initiation of flexion, preferably during the first 35° of flexion, is very low, and resistance is provided mainly by the main piston 30 subject to weight-activation via control rod 38. Thus, the swing control is prevented from adversely affecting the stance control.
The result of these measures is that stance control is largely separated from swing control, at least during flexion, to avoid unwanted operation of the stance control mechanism. This is shown diagrammatically in Figure 8. During flexion when the knee flexion angle is in a first knee flexion angle range, typically between 0° and 35° flexion, only the stance control mechanism (including main piston 30) is operative, depending on the loads applied to the leg. The swing control mechanism (including piston 46) is substantially ineffective in this range. In the latter stage of flexion, when the flexion angle is within a second knee flexion angle range, typically extending upwards from 35°, the stance control mechanism is largely inoperative due to the profile of the cam surface 10CS, and flexion is resisted only by the swing control mechanism. On extension, resistance to movement is exclusively provided by the swing control mechanism throughout both knee flexion angle ranges, as shown in Figure 8.
The knee mechanism described above may incorporate a stance cushioning device as shown in Figures 1 and 9. In this case the thigh component 12 is connected to a top plate 58 which is hinged at its anterior edge to the upper chassis part 10A by a pivot pin 60. A buffer 62 or spring is placed between the posterior portion of the plate 58 and the upper chassis part 10A. Such a combination allows some flexion at the knee while the knee mechanism is locked during the stance phase. Comparison of Figures 1 and 9 shows not only the compression of the buffer 62 in the weight-bearing condition, but also the relative approaching movement of the chassis parts 10A, 10B and the operation of the cross pin 38A.
Depending on the degree of stance cushioning required, it is possible for the spring stack 18 (Figures 1 and 5) to act as a cushioning device as well as a means of releasing the control rod 38 (Figures 1 and 7). In other words, a single pair of relatively movable portions and a single resilient element may perform both functions, in contrast to the arrangement shown in Figures 1 and 9.
An artificial leg characterised by:
an hydraulic piston and cylinder assembly coupled between the upper and lower leg components to resist at least said flexion movement during the stance phase, and
wherein one of the leg components includes at least two portions, one of which is coupled to the other of the leg components by the knee pivoting means and is movable relative to the other of the said two portions in response to the application of an axial load to the one leg component, and
wherein the control means are responsive to the relative movement of the said leg component portions to increase the resistance of the piston and cylinder assembly to the flexion movement when the knee flexion angle is within a first knee flexion angle range, but are unresponsive or responsive to a lesser degree when the knee flexion angle is within a second knee flexion angle range which is above the first angle range.
An artificial leg according to claim 1, characterised in that the piston and cylinder assembly has two ends each pivotally connected to a respective one of the leg components, wherein that end of the assembly which is connected to the one leg component is pivotally secured to the one leg component portion, and in that the control mechanism includes a control member forming part of the piston and cylinder assembly and arranged to engage the other leg component portion.
An artificial leg according to claim 1 or claim 2, characterised in that the said one leg component portion is pivotally attached to the said other leg component portion by means of an anterior pivotal connection, and in that the piston and cylinder assembly has two ends one of which is pivotally connected to the said one leg component portion by means of a posterior pivotal connection and the other of which is pivotally connected to the said other leg component.
An artificial leg according to any preceding claim, further characterised by a resilient element coupling the two leg component portions and arranged to resist the load-responsive relative movement of the two portions.
An artificial leg according to claim 1, characterised in that:
the said one leg component is the upper leg component,
the said one leg component portion is a knee joint carrier, the knee pivoting means comprising a fixed pivot joint carried by the knee joint carrier and defining a knee axis of rotation,
the knee joint carrier is pivotally attached to the said other leg component portion by means of a pivotal connection spaced from the knee axis, and
the upper leg component includes a resilient element arranged to be compressed when the knee joint carrier moves relative to the said other portion of the two leg component portions upon application of an axial load.
An artificial leg according to claim 5, characterised in that:
the pivotal connection between the said portions of the said upper leg component defines a pivot axis substantially parallel to and to the anterior of the knee axis,
the control means include a control member which forms part of the piston an cylinder assembly and which is engaged by the other portion of the said upper leg component portions adjacent the pivotal connection of the piston and cylinder assembly to the knee carrier.
An artificial leg according to claim 6, characterised in that the control member is associated with a control rod running parallel to a piston rod of the piston and cylinder assembly, the control rod being coupled to a valve in the assembly for restricting fluid flow in the assembly.
An artificial leg according to any of claims 5 to 7, characterised in that said other portion of said two leg component portions is itself pivotally attached by means of an anterior pivot connection to a third portion of the upper leg component located proximally with respect to the said one and the said other portions, the third portion being resiliently coupled to the other portion to the posterior of said anterior pivot connection to provide knee resilience during the stance phase.
An artificial leg according to any preceding claim, characterised in that the piston and cylinder assembly includes means for resisting flexion movement of the lower leg component relative to the upper leg component during the swing phase.
An artificial leg according to claim 9, characterised by means for reducing the resistance of the piston and cylinder assembly to flexion movement during the swing phase when the knee flexion angle is within the first angle range in comparison to the resistance to swing phase flexion when the flexion angle is within the second angle range.
An artificial leg according to claim 10, characterised in that the first and second angle ranges extend respectively below and above a predetermined knee flexion angle in the region of 30° to 40°.
An artificial leg according to claim 11, characterised in that the means for reducing resistance to flexion comprises at least one transfer passage in the piston and cylinder assembly, which passage is restricted when the flexion angle is greater than the predetermined angle.
An artificial leg according to any preceding claim, characterised in that the control means include means for progressively reducing said resistance to flexion movement with increasing angles of knee flexion.
that end of the assembly which is connected to the one leg component is pivotally connected to one of the said leg component portions,
the control means include (i) a control member which forms part of the piston and cylinder assembly and which is arranged to engage the other of the said leg component portions, and (ii) a cam associated with the other of the said leg component portions and shaped to reduce the resistance to flexion with increasing knee flexion angle.
An artificial leg according to claim 14, characterised in that:
said piston and cylinder assembly is coupled to the one leg component by a piston rod of the assembly,
said control member extends transversely from the piston rod and is associated with a control rod running parallel to the piston rod and coupled to a valve for restricting fluid flow in the assembly, and
the cam is located alongside the piston rod to engage the control member.
A knee mechanism for rotatably connecting a shin component of an artificial leg to a thigh component of the leg, characterised in that the mechanism comprises:
a first part for connection to one of the components,
a second part movable relative to the first part in response to the application of a load to the one component, the load being directed axially of the component,
knee pivoting means for pivotally coupling the second part to the other of the components,
an hydraulic piston and cylinder assembly coupled to one of the said parts and arranged to be coupled to the other component for resisting flexion movement of the one component relative to the other component during the stance phase, and
wherein the control means are responsive to the relative movement of the first and second parts of the mechanism to increase the resistance of the piston and cylinder assembly to the flexion movement when the knee flexion angle of the one component with respect to the other component is within a first knee flexion angle range, but are unresponsive or responsive to a lesser degree when the knee flexion angle is with a second knee flexion angle range which is above the first angle range.
an hydraulic piston and cylinder assembly coupled between the upper and lower leg components to resist at least the flexion movement during the stance phase, and
wherein one of the said leg components includes at least two portions, one of which is coupled to the other of the said leg components by the knee pivoting means and is movable relative to the other of the two portions in response to the application of an axial load to the one leg component,
wherein the piston and cylinder assembly has two ends each pivotally connected to a respective one of the leg components, and wherein that end of the assembly which is connected to the one leg component is pivotally connected to the said one leg component portion; and
wherein the control means are responsive to the load-responsive relative movement of the two leg component portions to increase the resistance of the piston and cylinder assembly to the flexion movement.
An artificial leg according to claim 17, characterised in that the said one leg component portion is pivotally attached to the said other leg component portion by means of an anterior pivotal connection, and in that the piston and cylinder assembly has two ends one of which is pivotally connected to the knee joint carrier by means of a posterior pivotal connection and the other of which is pivotally connected to the said other leg component.
An artificial leg according to claim 18, characterised in that:
the one leg component is the upper leg component,
the one leg component portion is a knee joint carrier, the knee pivoting means comprising a fixed pivot joint carried by the knee joint carrier and defining a knee axis of rotation,
the knee joint carrier is pivotally attached to the other leg component portion by means of a pivotal connection spaced from the knee axis, and
the upper leg component includes a resilient element arranged to be compressed when the knee joint carrier moves relative to the said other portion of the said leg component portions upon application of an axial load.
An artificial leg according to claim 19, characterised in that the knee axis is between the anterior and the posterior connections.
EP19920301254 1991-03-14 1992-02-17 An artificial leg Ceased EP0503775A1 (en)
GB919105464A GB9105464D0 (en) 1991-03-14 1991-03-14 An artificial leg
GB9105464 1991-03-14
GB9121417A GB2253791B (en) 1991-03-14 1991-10-09 An artificial leg
GB9121417 1991-10-09
EP0503775A1 true EP0503775A1 (en) 1992-09-16
ID=26298591
EP19920301254 Ceased EP0503775A1 (en) 1991-03-14 1992-02-17 An artificial leg
EP (1) EP0503775A1 (en)
JP (1) JPH05237143A (en)
WO1993025165A1 (en) * 1992-06-09 1993-12-23 Gramnaes Finn Artificial joint with a hydraulic damping cylinder
WO1994006374A1 (en) * 1992-09-14 1994-03-31 Chas A Blatchford & Sons Limited Artificial leg
DE4327352C1 (en) * 1993-08-14 1995-04-06 Thomas Schmitt Cosmetically designed leg prosthesis
FR2711512A1 (en) * 1993-10-27 1995-05-05 Cros Claude Gerard Prosthetic component for the knee joint
FR2763837A1 (en) * 1997-06-03 1998-12-04 Amy Maudon Prosthesis for lower limb
GB2338653A (en) * 1998-06-26 1999-12-29 Blatchford & Sons Ltd A lower limb prosthesis
GB2399503A (en) * 2003-03-20 2004-09-22 Blatchford & Sons Ltd Prosthetic knee joint mechanism
CN100508916C (en) 2002-11-21 2009-07-08 株式会社纳博克 Prosthetic leg with knee braking function
JP2002021908A (en) * 2000-06-30 2002-01-23 Showa Corp Hydraulic shock absorber
JP5184928B2 (en) * 2008-03-26 2013-04-17 株式会社今仙技術研究所 Knee joint structure of the prosthesis
GB661131A (en) * 1948-07-09 1951-11-14 Ulrich Konrad Henschke Improvements in or relating to prosthetic devices
GB1221778A (en) * 1967-04-05 1971-02-10 Blatchford & Sons Ltd Improved method of making an artificial leg
DE2740804A1 (en) * 1976-09-13 1978-03-16 Blatchford & Sons Ltd Prosthetic leg with the knee joint
1992-02-17 EP EP19920301254 patent/EP0503775A1/en not_active Ceased
1992-03-12 JP JP5392392A patent/JPH05237143A/en active Pending
WO1998055054A1 (en) * 1997-06-03 1998-12-10 Amy Maudon Lower member prosthesis
US7588604B2 (en) 2002-11-21 2009-09-15 Nabco Limited Prosthetic leg with knee braking function
EP1570817A4 (en) * 2002-11-21 2006-07-05 Nabco Ltd Prosthetic leg with knee braking function
GB2399503B (en) * 2003-03-20 2006-03-29 Blatchford & Sons Ltd Prosthetic knee joint mechanism
JPH05237143A (en) 1993-09-17
US6582469B1 (en) 2003-06-24 Knee prosthesis
US20100161067A1 (en) 2010-06-24 Knee prosthesis
US5405408A (en) 1995-04-11 Artificial knee having dual flexion action during locomotion
1996-08-14 18R Refused