Prosthetic knee joint

• US 5,246,465 A
• Filed: 04/19/1991
• Issued: 09/21/1993
• Est. Priority Date: 04/19/1991
• Status: Expired due to Fees

• Current Assignee: Richard G. Rincoe
• Original Assignee: Richard G. Rincoe
• Inventors: Hull, Marlin B., Rincoe, Richard G.
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): BURKE, ELIZABETH
• Application Number:
  US07/687,831
• Time in Patent Office: 886 Days
• Field of Search: 623/25, 623/39, 623/43, 623/44, 623/45, 623/53, 623/55, 623/24, 623/64, 901/21, 901/25, 901/28
• US Class Current: 623/39
• CPC Class Codes: A61B 2017/00685 Archimedes screw
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2002/5075 Multiple spring systems including two or more helical springs
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors

Abstract

A robotic knee for mounting on an upper leg stump of an allows movement from a standing position to a normal walking position and then to a kneeling position and return to a standing position. A mounting plate receives the upper leg stump of an amputee. The knee includes a housing having a drive motor which can be rotated in one direction to bend the knee and then reversed to straighten the knee. The drive motor turns a worm gear which engages a main drive gear. A pair of extension pulleys is mounted on a main drive gear shaft attached to the main drive gear. A pair of extension cables is attached at a first end to the extension pulleys and wrapped thereon. A second end of the extension cables is attached to a front portion of a mounting plate. A pair of flexion pulleys is also attached to the main drive gear. A pair of flexion cables is attached at a first end to the flexion pulleys and wrapped thereon. A second end of the flexion cables is attached to a rear portion of the mounting plate. On a bottom of the mounting plate is disposed a rack with rack teeth. The rack teeth engage a walking gear segment, thereby allowing the mounting plate to be moved up and down in a rocking motion by the extension and flexion cables, the rack teeth rock on the walking gear segment allowing the knee to simulate a natural rocking motion.

Claims

1. A prosthetic knee for mounting on an upper leg stump, the knee comprising:

a knee housing;

a drive motor mounted in said knee housing for pivoting the knee;

a mounting plate disposed on top of said knee housing for securing said knee to the upper leg stump, said mounting late having a front portion, a rear portion, a top and a bottom, said mounting plate having at least one gear rack attached to said bottom thereof; and

a gear assembly mounted in said knee housing and including;

a main drive gear with drive shaft connected to said knee housing, said drive motor engaging said main drive gear;

at least one extension pulley mounted on said drive shaft with one end of an extension cable attached to said extension pulley and a second end of said extension cable attached to said front portion of said mounting plate;

at least one flexion pulley mounted on said drive shaft with one end of a flexion cable mounted on said flexion pulley and a second end of said flexion cable attached to a coil spring connected to said rear portion of said mounting plate; and

at least one walking gear segment attached to said knee housing, said gear rack engaging said walking gear segment for pivoting said mounting plate from a first position to a second position.

2. The knee as described in claim 1 wherein said gear assembly includes at least one kneeling gear segment attached to said knee housing, said kneeling gear segment engaging a quarter gear segment mounted on one end of said gear rack when said mounting plate is pivoted from said second position to a third position.

3. The knee as described in claim 1 wherein said mounting plate includes a pair of side support bars attached to opposite sides of said mounting plate and disposed adjacent sides of the top of said knee housing.

4. The knee as described in claim 1 further including an artificial lower leg attached to a bottom of said knee housing.

5. The knee as described in claim 1 further including an artificial lower leg with a prosthetic ankle attached to a bottom of said knee housing.

6. The knee as described in claim 5 wherein said prosthetic ankle is attached to an artificial foot, said prosthetic ankle having means for raising and lowering said artificial foot.

7. A prosthetic knee joint system for mounting on a fermoral leg stump of an amputee, and which undergoes powered movement which simulates a standing position, a powered natural rocking or walking motion, a powered stair climbing motion, a sitting or kneeling position, or combination s thereof, with ease of movement from position to position, the prosthetic knee joint system including:

a housing, said housing having a top portion;

a drive motor attached to said housing;

attachment means located at the top portion of the housing, said attachment means having a top surface, a bottom surface, a front portion, and a rear portion, said top surface of said attachment means being designed to receive the femoral leg stump of an amputee, said rear portion of said attachment means designed to pivot away from said top portion of said housing;

a rotatably mounted shaft within said housing;

means for translating motion of said motor into rotation of said rotatably mounted shaft;

at least one first flexible line having a first end and a second end;

at least one first means for winding said at least one first flexible line, said at least one first means for winding connected to said rotatably mounted shaft for rotation when said shaft is rotated, said first end of said at least one first flexible line being associated with said at least one first means for winding, said at least one first flexible line being designed and positioned to be wrapped onto or played off of said at least one first means for winding with which it is associated in response to the rotation of said rotatably mounted shaft, and with said second end of said at least one first flexible line connected to said front portion of said attachment means;

at least one second flexible line having a first end and a second end;

at least one second means for winding said at least one second flexible line, said at least one second means for winding connected to said rotatably mounted shaft for rotation when said shaft is rotated, said first end of said at least one second flexible line being associated with said at least one second means for winding, said at least one second flexible line being designed and positioned to be wrapped onto or played off of said at least one second means for winding with which it is associated in response to the rotation of said rotatably mounted shaft, and with said second end of said at least one second flexible line connected to said rear portion of said attachment means;

at least one curved gear with gear teeth fixedly connected to the housing, said at least one curved gear normally positioned adjacent to and below said bottom surface of said attachment means;

at least one gear rack with gear rack teeth disposed on said bottom surface of said attachment means, said at least one gear rack normally being aligned with and in contact with said at least one curved gear, with at least some of said gear rack teeth of said at least one gear rack normally engaging some of said gear teeth of said at least one curved gear with which it is aligned and in contact;

whereby, when said motor is activated it causes said means for translating the motion of said motor to cause rotation of said rotatably mounted shaft, which in turn causes said at least one first means for winding and said at least one second means for winding to rotate, resulting in said at least one first flexible line being either wrapped onto or played off of said at least one first means for winding with which it is associated, while at the same time said at least one second flexible line undergoes a reverse operation, and is either played off of or wrapped onto said at least one second means for winding with which it is associated, resulting in one of said at least one first and second flexible lines which is being wrapped onto a respective one of said at least one first and second means for winding with which it is associated pulling down a portion of said attachment means to which that line is connected, and another of said at least one first and second flexible lines which is played off of a respective one of said at least one first and second means for winding with which it is associated allowing a portion of said attachment means to which that line is connected to be raised in a manner such that said front portion or said rear portion of said attachment means may be caused to move up or down in a continuously pivoting or in a rocking motion by movement of said at leas tone first and second lines, with at least some of said gear rack teeth normally engaging and pivoting on some of said gear teeth, so that, depending upon direction and duration of activation of the motor, movement of the prosthetic knee joint system simulates a standing position, a powered natural rocking or walking motion, a powered stair climbing motion, a sitting or kneeling position, or combinations thereof, with each of powered movement from position to position.

8. The prosthetic knee joint system of claim 7 in which a worm gear is caused to rotate by said motor, and said worm gear in turn causes a drive gear, which carries said rotatably mounted shaft, to rotate.

9. The prosthetic knee joint system of claim 8 in which rotatably mounted shaft is a gear shaft.

10. The knee as described in claim 7 wherein said drive motor is an electric motor, and wherein said electric motor is controlled by myoelectric means.

11. The prosthetic knee joint system of claim 7 in which at least one of said at least one first means for winding and said at least one second means for winding are curved winding elements.

12. The prosthetic knee joint system of claim 11 in which at least one of said at least one first means for winding and said at least one second means for winding are pulleys.

13. The prosthetic knee joint system of claim 7 in which at least one of said at least one first and said at least one second flexible lines are cables.

14. The prosthetic knee joint system of claim 7 in which a resilient element is connected intermediate said second end of said at least one first flexible line and said front portion of said attachment means.

15. The prosthetic knee joint system of claim 14 in which said resilient element is a coiled spring.

16. The prosthetic knee joint system of claim 7 in which a pair of first winding means, a pair of first flexible lines, a pair of second winding means, and a pair of second flexible lines, are present and used in the system.

17. The prosthetic knee joint system of claim 7 in which a pair of curved gears are fixedly connected to the housing adjacent to and below said bottom surface of said attachment means, and a pair of gear racks are disposed on said bottom surface of said attachment means, with each gear rack being aligned with and in contact with one of said curved gears, with at least some of said gear rack teeth of each gear rack normally engaging some of said gear teeth of said curved gear with which it is aligned and in contact.

18. The prosthetic knee joint system of claim 7 in which a kneeling gear having gear teeth is fixedly located adjacent to and aligned with said at least one curved gear and below said bottom surface of said attachment means, and a quarter gear segment having gear teeth is mounted on said bottom surface of said attachment means adjacent to and aligned with said at least one gear rack and normally below said quarter gear segment;

whereby when said at least one curved gear and an associated gear rack pivot said attachment means to a given position above horizontal, at least some of said gear teeth of said quarter gear segment are placed into contact with some of said gear teeth of said kneeling gear, and said teeth of said at least one gear rack are disengaged from said teeth of said at least one curved gear, thereby allowing additional rotation of said attachment means above the horizontal.

19. The prosthetic knee joint system of claim 18 in which said gear teeth of said quarter gear begin to engage said gear teeth of said kneeling gear when said attachment means reaches about 75°

from the horizontal, and which is capable of extending to a position of a least about 135°

from the horizontal.

20. A prosthetic knee joint system for mounting on a femoral leg stump of an amputee, and which undergoes powered movement which simulates a standing position, a powered natural rocking or walking motion, a powered stair climbing motion, a sitting or kneeling position, or combinations thereof, with ease of movement from position to position, the prosthetic knee joint system including:

a housing, said housing having a top portion;

an electric drive motor controlled by myoelectric means attached to said housing;

attachment means located at the top portion of the housing, said attachment means having a top surface, a bottom surface, a front portion, and a rear portion, said top surface of said attachment means being designed to receive the femoral leg stump of an amputee, said rear portion of said attachment means designed to pivot away from said top portion of said housing;

a worm gear within said housing, said worm gear positioned to be rotated by said motor;

a drive gear within said housing, said drive gear positioned to be rotated by said worm gear;

a rotatably mounted drive shaft carried by said drive gear within said housing, said drive shaft designed to be rotated when said drive gear rotates;

a pair of first flexible lines, each first flexible line having a first end and a second end;

a pair of first curved winding elements, each said first curved winding element connected to said drive shaft for rotation when said drive shaft is rotated by said drive gear, said first end of each said first flexible line being associated with one said first curved winding element, each first flexible line being designed and positioned to be wrapped onto or played off of said first curved winding element with which it is associated in response to rotation of said rotatably mounted shaft, and with said second end of each said first flexible line connected to said front portion of said attachment means;

a pair of second flexible lines, each having a first end and a second end;

a pair of second curved winding elements, each said second curved winding element connected to said drive shaft for rotation when said drive shaft is rotated by said drive gear, said first end of each said second flexible line being associated with one said second curved winding element, each second flexible line being designed and positioned to be wrapped onto or played off of said second curved winding element with which it is associated in response to the rotation of said rotatably mounted shaft, and with said second end of each said second flexible line connected to said front portion of said attachment means;

a pair of curved gears with gear teeth, each curved gear fixedly connected to the housing, each said curved gear normally positioned adjacent to and below said bottom surface of said attachment means;

a pair of gear racks with gear rack teeth, each gear rack disposed on said bottom of said attachment means, each gear rack normally being aligned with and in contact with one said curved gear, with at least some of said gear rack teeth of each gear rack normally engaging some of said gear teeth of said curved gear with which it is aligned and in contact;

whereby, when said motor is activated it causes translation of motion of said motor to cause rotation of said rotatably mounted shaft, which in turn causes each first curved winding element and each second curved winding element to rotate resulting in each first flexible line being either wrapped onto or played off of each first curved winding element with which it is associated, while at same time each second flexible line undergoes a reverse operation, and is either played off of or wrapped onto each second curved winding element with which it is associated, resulting in each first or second flexible line which is being wrapped onto each first or second curved winding element with which it is associated pulling down a portion of said attachment means to which that line is connected, and each first or second flexible line which is played off of each first or second curved winding element with which it is associated allowing a portion of said attachment means to which that line is connected to be raised in a manner such that said front portion or said rear portion of said attachment means may be caused to move up or down in a continuously pivoting or in a rocking motion by movement of said first and second lines, with at least some of said gear rack teeth normally engaging and pivoting on some of said gear teeth, so that, depending upon direction and duration of activation of the motor, movement of the prosthetic knee joint system simulates a standing position, a powered natural rocking or walking motion, a powered stair climbing motion, a sitting or kneeling position, or combinations thereof, with each of powered movement from position to position.