Topic
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.
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Patent•
25 May 1988
TL;DR: In this article, a closed loop servo circuit is used to control the motor in response to the load signal and the velocity signal to control rotation of the output shaft of the servo motor.
Abstract: A muscle exercise and/or rehabilitation apparatus includes a fixture against which a force can be applied; a sensor which senses the force applied to the fixture and produces a load signal corresponding thereto; a speed detector which produces a velocity signal corresponding to the speed of the fixture; a servo motor which produces a rotational output of an output shaft thereof; a closed loop servo circuit which controls the motor in response to the load signal and the velocity signal to control rotation of the output shaft of the servo motor; and a conversion device connected between the fixture and the output shaft of the servo motor for translating the rotational output of the output shaft to linear motion of the fixture, the conversion device including a frame formed by a base, two spaced vertical support bars extending upwardly from the base, and an upper cap securing upper ends of the vertical support bars together, two vertical guide rods supported by the frame, a slide movable along the guide rods in such linear motion, an operational pulley rotatably connected with the output shaft of the servo motor, and a rope secured to the slide and wrapped about the pulley for controlling movement of the slide in the linear motion in response to the output shaft of the servo motor.
60 citations
TL;DR: In this paper, a parametric super element model for cable passing through multiple pulleys is presented for the static analysis of structures, where the amounts of cable passages over pulleys are introduced as additional degrees-of-freedom in the finite element model and the relationship between cable tensions at two sides of each pulley is imposed based on the friction law or empirical data.
59 citations
Patent•
25 May 1984
TL;DR: A rotatable exercise mechanism for interacting with the body in order to perform exercises is described in this article, where a cable is secured to the pulley such that the cable can be wound in opposite directions about the mechanism.
Abstract: A rotatable exercise mechanism for interacting with the body in order to perform exercises. The rotatable exercise mechanism includes a pulley mounted on the frame. A cable is secured to the pulley such that the cable can be wound in opposite directions about the pulley. As the pulley is rotated in either a clockwise or counter-clockwise direction, the cable is both paid out from and wound onto the pulley. An adjustable resistive force is supplied for interacting with the cable being wound onto or paid out from the pulley. A crank for applying a rotative force to the pulley is also supplied. The pulley is rotated by applying a rotative force to the pulley capable of overcoming the resistive force applied to the cable.
59 citations
TL;DR: The biomechanics of the reconstructed flexor retinacular pulley system are poorly defined and recommendations of clinical application include the following: two pulleys should be placed, one proximal and one distal to each joint, and three individual joints can be balanced by maintaining minimal bowstringing at all three joints.
Abstract: The biomechanics of the reconstructed flexor retinacular pulley system are poorly defined. We used a mathematical theoretical model, confirmed by a cadaver model, and a clinical radiographic model to evaluate a variety of different joint and pulley combinations. We examined twenty-four sets of radiographs of 12 fingers in 9 patients for whom excursion was measured and predicted by the mathematical model. The 30 pulley combinations evaluated in the in vitro cadaver model showed statistical correlation with the biomechanical mathematical model. Recommendations of clinical application on the basis of this information include the following: (1) Two pulleys should be placed, one proximal and one distal to each joint. (2) These two pulleys should be balanced about the joint axis both in distance from the axis and in pulley height. (3) They should be positioned at the edge of the flare of the metaphysis. (4) The three individual joints can be balanced, one to another, by maintaining minimal bowstringing at all three joints. In this way, the relative excursion at the joint and torque at the joint will be maintained in a physiological ratio as close to normal as possible.
59 citations
Patent•
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20 Dec 2002
TL;DR: In this article, a lift belt with a ribbed profile on a pulley engaging surface is described, which exhibits increased load lifting capacity due to the increased surface area of the ribs as compared to a flat belt.
Abstract: The invention comprises a lift belt (10) having a ribbed profile (25) on a pulley engaging surface. The lift belt also comprises steel tensile cords (15) within an elastomeric body. The ribbed profile engages a ribbed profile on a pulley. The lift belt exhibits increased load lifting capacity due to the increased surface area of the ribs as compared to a flat belt. The belt (10) also comprises conductive tensile cords having a resistance (Br). A change in resistance is used for measuring a belt condition as well as a belt load.
59 citations