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.

The A3 pulley

Abstract: The tendon-pulley geometry and gliding resistance with and without the A3 pulley were compared in 6 fresh human cadaver fingers. We measured the x-ray images of the distal A2 pulley-tendon angle and proximal A4 pulley-tendon angle with varying degrees of proximal interphalangeal joint flexion between 0 degrees and 120 degrees before and after A3 pulley resection. The gliding resistance of the flexor digitorum profundus tendon under the A2 pulley was also measured at varying tendon-pulley angles. With the A3 pulley removed, the tendon-pulley angle significantly increased compared with the A3 intact state. The gliding resistance between tendon and pulley quadratically increased as the tendon-pulley angle increase from 0 degrees to 60 degrees. These results indicate that the A3 pulley might serve to reduce tendon-pulley gliding resistance by reducing the tendon-pulley angle during finger flexion.

Mechanical belt tensioner construction

Abstract: A tensioning device for maintaining a predetermined amount of tensioning force on an endless drive belt for a vehicle accessories drive system. A housing is mounted in a fixed position on the vehicle engine adjacent the drive belt. A lever is pivotally mounted on a shaft which is located within the housing and extends generally radially outwardly from the housing and is adapted to move in a belt tensioning direction. A first pair of cylindrical, torsional coil springs is telescopically mounted on the shaft, with the springs being located one on each side of the lever. A second pair of cylindrical, torsional coil springs is telescopically concentrically mounted on the shaft and surrounds the first spring pair. One end of each spring is attached to the housing with the other spring ends being attached to the lever. The spring pairs are placed in torsion and bias the lever in the belt tensioning direction. An idler pulley is mounted on the end of the lever and is moved into tensioning engagement with the drive belt by the torsion springs, or alternately one of the vehicle accessories is mounted on the end of the lever for tensioning the drive belt which is engaged by the accessory pulley. The tensioner construction enables a large tensioning force to be obtained from a relatively small, compact, simple spring arrangement by using three or more torsional springs.

Endless power transmission belt

Abstract: An endless power transmission belt (10) comprises a plurality of V-belt components (11) spaced appart laterally of the direction of extent of the belt and a tie band (12) connecting the V-belt components (11) together to form a unitary structure. The tie band (12) is composed of a plurality of cord fabric layers (13) disposed one on top of another, each layer (13) comprising parallel cords (17) which are embedded in an elastomeric material (15, 16) and which are inclined with respect to the direction of extent of the belt (10). Each adjacent pair of cord fabric layers (13) have their cords mutually inclined at an angle between 95° and 155°, and also have a layer (14) of elastomeric material interposed therebetween to prevent the cords in said adjacent layers from rubbing against each other. The endless belt (10) has high stretchability both lengthwise and widthwise thereof, permitting the tie band (12) to conform to the shape of the V-belt components (11) when the latter locate in pulley grooves.

Safety suspension unit and harness for developing jumps in figure skating

Abstract: A safety suspension unit with a tracking carriage connectable to an elevated fixed track, the suspension unit having a spring loaded pulley system with a support cable connected to a harness for aiding a skater, in the learning and practicing of jumps and spins. The tension in the spring which loads the pulley system is increased as the support cable is dispensed.