Pulley

About: Pulley is a research topic. Over the lifetime, 51636 publications have been published within this topic receiving 178220 citations. The topic is also known as: drum & block.

Force reflecting hand controller

Abstract: A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

Steering mechanism for bi-directional catheter

Abstract: A bi-directional catheter with nearly double the throw in its catheter tip deflection defines a puller wire travel path having a U-turn a pulley which minimizes the offset angle between the puller wire and the longitudinal axis of the control handle while maximizing the travel distance of that puller wire for any given distance traveled by the pulley drawing the puller wire. In particular, the control handle of the catheter which includes a steering assembly having a lever arm carrying a pair of pulleys for drawing corresponding puller wires to deflect the tip section of the catheter. The pulleys are rotatably mounted on opposing portions of the lever arm such that one pulley is moved distally as the other pulley is moved proximally when the lever arm is rotated. Because each puller wire is trained on a respective pulley, rotation of the lever arm causes the pulley that is moved proximally to draw its puller wire to deflect the tip section in the direction of the off-axis lumen in which that puller wire extends.

Anatomy of the finger flexor tendon sheath and pulley system

Abstract: Additions and changes in the description of the anatomy of the finger flexor sheath and pulleys that I published in 1974 and 1975 have prompted me to restudy this system. Sixty-one fresh human cadaver fingers were dissected using the operating room microscope. This study demonstrated a flexor synovial sheath composed of visceral and parietal elements from the neck of the metacarpal to the distal interphalangeal joint, which was overlaid with a series of retinacular structures (pulleys). The pulleys identified were the palmar aponeurosis pulley, five annular pulleys, and three cruciform pulleys. Although significant variations were noted in the morphology of the first annular and the cruciform pulleys sufficient similarity exists between my first description and the present study to support the use of the original descriptive terminology. A significant addition to the pulley system is the palmar aponeurosis pulley described by Manske and Lesker.