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.

Infinitely variable cone-pulley transmission

Abstract: A cone pulley transmission is disclosed which includes an infinitely actuatable and adjustable transmission wherein an axially displaceable cone pulley disc is adjustable by application of hydraulic tensioning so as to generate the pressure forces acting on a transmission belt rotating between the cone pulley discs, with the tensioning being controlled by a pressure medium through a sliding control valve. The tensioning is provided by different sized pressure chargeable surfaces and is throttled to different degrees with respect to the associated outlet of the sliding control valve. In this connection, it is provided that at least one outlet can be changed as a function of certain parameters.

Passive mechanical gravity compensation for robot manipulators

Abstract: A simple mechanical method for passively compensating for gravitationally induced joint torques is presented. This energy-conservative gravity-compensation method is suitable for a variety of manipulator designs. With cables and appropriate pulley profiles, changes in potential energy associated with link motion through a gravity field can be mapped to changes in strain energy storage in spring elements. The resulting system requires significant energy input only for acceleration and deceleration or to resist external forces. A testbed with both single- and double-link configurations has demonstrated the efficiency and accuracy of this gravity compensation method, as well as its robustness under dynamic loading conditions. >

Cable actuated end-effector for a surgical instrument

Abstract: Various embodiments are directed to a surgical instrument comprising a handle, a shaft coupled to the handle and extending along a longitudinal axis, an end effector, and a cable. The end effector may comprise a first jaw member, a second jaw member and a reciprocating member. The cable may extend distally from the handle through the shaft to a first pulley of the first jaw member. From the first pulley, the cable may extend proximally to the reciprocating member, such that proximally directed motion of the cable exerts a distally directed force on the reciprocating member.

Apparatus and method for polishing a flat surface using a belted polishing pad

Abstract: The present invention relates to an apparatus and method of Chemical Mechanical Planarization ("CMP") for wafer, flat panel display (FPD), and hard drive disk (HDD). The preferred apparatus comprises a looped belt spatially oriented in a vertical direction with respect to a ground floor. A polishing pad is glued to an outer surface of the belt. At an inner surface of the belt, there are a plurality of wafer supports to support the wafers while they are in polishing process. Wafers are loaded from a wafer station to a wafer head using a handling structure before polishing and are unloaded from the wafer head to the wafer station after polishing. An electric motor or equivalent is used to drive the looped belt running over two pulleys. An adjustment means is used to adjust the tension and position of the belt for smooth running. This new CMP machine can be mounted in multiple orientations to save manufacturing space.

In vivo registration of Achilles tendon forces in man. I. Methodological development.

Abstract: Mechanical behavior of muscle and its control is largely unknown under normal movement conditions. The present report deals with the methodological development to record directly in vivo forces from the human achilles tendon (AT) when the subjects perform normal movements ranging from slow walking to maximal sprinting and jumping. The development began with animal experiments, which dealt with the transducer design, surgical operation procedures, and duration of implantation. The first human experiment utilized an E form transducer implanted around the AT under local anesthesia. The transducer was kept in situ for 7 days, and on the 8th day recordings were made on simple plantar flexion movements and during slow walking. Further development led to final selection of a "buckle"-type transducer, and the measurements can be made immediately after operation and they usually last 2-3 h. The AT transducer can be calibrated by placing the subject in a prone position on to a calibration table. His operated foot was placed in a special shoe, the axis of which coincided with that of the ankle joint. A pulley system with known weights was used to dorsiflex the foot. Taking into consideration the geometrical arrangement of the AT transducer, axis of rotation, and the pulley system, the exact values of AT forces could be calculated. The actual measurements incorporate the use of EMG recordings of the leg extensor muscles and various external force measurements, such as long force platform or oscillating ergometers. The transducer is removed immediately after the measurements and the subjects recover.