Powered prosthesis with torque-sensitive actuation
Inventors
Lenzi, Tommaso • GABERT, Lukas R. • ORTOLANO, Brendon M.
Assignees
University of Utah • University of Utah Research Foundation Inc
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Publication Number
US-12433771-B1
Publication Date
2025-10-07
Expiration Date
Abstract
A powered prosthesis device includes an artificial joint body, pivotal about a joint axis, an input motor, and a transmission, operable to transfer force from the input motor to the artificial joint body. The transmission includes a crank, pivotally coupled to the artificial joint body about a crank axle rotatable about a crank axis. The input motor is operably coupled to the crank such that movement of the input motor causes the crank to pivot about the crank axis. A primary compression spring is carried by the artificial joint body, the primary compression spring being operably coupled to the crank. Movement of the input motor results in the crank transferring force to the artificial joint body about the crank axle and through the primary compression spring to cause the artificial joint body to pivot about the artificial axis.
Core Innovation
The invention relates to a powered prosthesis device having an artificial joint body pivotal about a joint axis. An input motor and a transmission transfer force from the input motor to the artificial joint body. The transmission includes a crank pivotally coupled to the artificial joint body about a crank axle rotatable about a crank axis, and movement of the input motor causes the crank to pivot about the crank axis.
The transmission further includes a primary compression spring carried by the artificial joint body and operably coupled to the crank. The primary compression spring is coupled on one end to the crank and on an opposing end to a portion of the artificial joint body, or is continually compressed between the crank and the artificial joint body through a full range of motion of the artificial joint body. Movement of the input motor results in the crank transferring force to the artificial joint body about the crank axle and through the primary compression spring to cause the artificial joint body to pivot about the joint axis.
In additional configurations, the powered prosthesis includes a ball screw spindle rotatable by the input motor, a ball nut threadably engaged with the ball screw spindle to translate the ball nut, and a connecting arm translating movement of the ball nut into movement of the crank. The input motor includes a rotor fixed relative to the ball screw spindle so movement of the rotor results directly in movement of the ball screw spindle. The arrangement also provides a primary pre-loader and a secondary compression spring carried by the artificial joint body that is separably contactable by the crank, enabling a first transmission ratio configuration where the crank engages both springs and a second transmission ratio configuration where the crank remains engaged with the primary compression spring and is separated from contact with the secondary compression spring.
Claims Coverage
The document provides two independent claims, covering a powered prosthesis device with a spring-compression crank transmission and, in a further independent claim, a ball-screw-driven linkage with threadably engaged pre-loaders and a separable secondary spring transmission-ratio configuration. Across the independent claims, the core inventive features include the artificial joint pivot driven by crank motion via a primary compression spring, and the ball screw spindle/ball nut/connecting arm translation arrangement integrated with rotor-to-spindle fixation and primary/secondary pre-loaders.
Crank-pivot transmission with primary compression spring coupling
A crank pivotally coupled to the artificial joint body about a crank axle rotatable about a crank axis, wherein movement of the input motor causes the crank to pivot about the crank axis; and a primary compression spring carried by the artificial joint body, the primary compression spring being operably coupled to the crank such that movement of the input motor results in the crank transferring force to the artificial joint body about the crank axle and through the primary compression spring to cause the artificial joint body to pivot about the joint axis.
Ball screw translation linking rotor to crank with continual spring compression and ratio switching
A crank pivotally coupled to the artificial joint body, with the crank axis and the joint axis being laterally displaced from one another; a primary compression spring rotatably coupled to the artificial joint body and rotatably coupled to the crank, the primary compression spring being continually compressed between the crank and the artificial joint body through a full range of motion of the artificial joint body; a secondary compression spring carried by the artificial joint body and separably contactable by the crank; a ball screw spindle rotatable by the input motor; a ball nut threadably engaged with the ball screw spindle such that rotation of the ball screw spindle results in translation of the ball nut; and a connecting arm extending between the ball nut and an input side of the crank to translate movement of the ball nut into movement of the crank, wherein the input motor includes a rotor fixed relative to the ball screw spindle such that movement of the rotor results directly in movement of the ball screw spindle; and a range of motion of the artificial joint body includes i) a first transmission ratio configuration in which the crank engages both the primary and secondary compression springs and ii) a second transmission ratio configuration in which the crank remains engaged with the primary compression spring and is separated from contact with the secondary compression spring.
Collectively, the independent claims cover a powered prosthesis where an artificial joint body pivots about a joint axis under force transferred from an input motor through a pivoting crank and a primary compression spring, with the further independent coverage adding a ball screw spindle/ball nut/connecting arm translation path, rotor-to-spindle fixation, and a separable secondary compression spring arrangement providing first and second transmission ratio configurations.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
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