scispace - formally typeset
Search or ask a question
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.


Papers
More filters
Patent
30 Nov 1995
TL;DR: The plenum chambers of a hydromechanical torque sensor can be connected to or sealed from each other as a consequence of change in the effective dia. of the pulley to change the ratio of a transmission including a pulley as mentioned in this paper.
Abstract: The hydromechanical torque sensor (14) has cam discs (18,19) with conforming cam faces between which are located spreading elements (20) to tend to move the cam faces apart under high torque to act in use on one half of the expanding pulley via first and second plenum chambers (22,23) connected to a source of hydraulic fluid under pressure. Supply to the chambers is via a throttle.The plenum chambers of the torque sensor can be connected to or sealed from each other as a consequence of change in the effective dia. of the pulley to change the ratio of a transmission including the pulley. The connection between the chambers may be allowed by one-way action of a lip seal (67) or by a valve.

27 citations

Patent
18 Sep 1990
TL;DR: In this article, an encoder is used to track the rotational movement of a drawworks drum and a second encoder which is part of a calibrator which precisely measures the location of the travelling block relative to a known vertical location.
Abstract: Methods and apparatus for accurately determining drill bit depth are provided. A hook load is sampled at a rate of at least 4 Hz and is compared to a load threshold to establish a slips-in condition. A determination is made retroactively that the drill string stopped moving when the hook load passed through a high dynamic threshold. On the slips-out procedure, the identical high threshold is used, with movement established when the hook load exceeds the high threshold. The high dynamic threshold corresponds to the points at which the drill string actually stops and starts moving in the slips-in and slips-out procedures. The apparatus provided is a drawworks encoder mounting assembly which retrofits an auxiliary brake section of the drawworks or the rotary seal air coupler of a drawworks clutch. A split ring gear fits around and is secured to the rotating cylinder of the rotary seal air coupler. The split ring gear is part of a pulley having another gear and a drive belt, such that rotation of the drum and rotorseal air coupler cylinder is translated to a shaft of an encoder coupled to the second gear. The encoder thereby tracks the rotational movement of the drawworks drum. At desired times, also provided is a second encoder which is part of a calibrator which, via a calibrator wire, precisely measures the location of the travelling block relative to a known vertical location. The first and second encoder readings are compared continuously and are used to provide excellent calibrations between the drum rotation and the travelling block movement.

27 citations

Patent
05 Oct 1972
TL;DR: In this paper, a pair of endless belts are provided, with each belt being operatively connected between an upper pulley at one end and the lower one at the other end, each with a single twist between the ends thereof.
Abstract: A housing is disclosed having upper and lower spaced pulleys at each end. A pair of endless belts are provided, with each belt being operatively connected between an upper pulley at one end and the lower pulley at the other end. The belts are each provided with a single twist between the ends thereof. A mailing envelope inserted between the pulleys at one end will be engaged by the belts which are being driven to thereby carry the envelope to the other end. The envelope is inverted as it is carried by the twisted belts.

27 citations

Patent
02 Mar 1989
TL;DR: In this paper, an infinitely adjustable cone pulley transmission is described, in which pressure medium is fed by one or more pumps by way of a hydraulic control unit in order to adjust the transmission ratio.
Abstract: The invention relates to an infinitely adjustable cone pulley transmission, to which pressure medium is fed by one or more pumps by way of a hydraulic control unit in order to adjust the transmission ratio These transmissions are generally driven by an internal combustion engine at rotational speeds of between 1000 6000 min , resulting in a quantity of pressure medium proportional to the speed, which quantity is not sufficient for the functioning of the cone pulley transmission under widely varying operating conditions and considerably impairs the overall efficiency By means of the invention, the quantity of pressure medium is controlled as required by means of sensors, an electronic processing unit and a solenoid valve according to the instantaneous operating states (engine speed, accelerator pedal position, etc)

27 citations

Patent
12 Feb 1999
TL;DR: In this article, an exercise trainer has a frame with a flywheel supported on the frame and first and second crank arms having a common axle on the flywheel for pivotal reciprocating movement.
Abstract: An exercise trainer having a frame with a flywheel supported on the frame and first and second crank arms having a common axle on the flywheel. A first foot link and a second foot link are respectively connected to the crank arms for pivotal reciprocating movement. The links have channel tracks and an elongated tunnel. Bearing surfaces support the first foot links rearwardly and engage the channels. Foot pedals are mounted on the foot links for relative movement on the foot links. A flexible member such as a belt, cable, or chain is connected to the foot pedal. A lower portion of the flexible member is connected to a fixed location or ground on the frame. A forward and rearward rotational support such as a pulley receives the flexible member defining a lower portion wrapping around the pulleys and connected to the frame. The pulleys are mounted in the tunnel to provide movement of the foot pedals greater than twice the length of the crank arm.

27 citations


Network Information
Related Topics (5)
Torque
80.7K papers, 707.9K citations
76% related
Ankle
30.4K papers, 687.4K citations
71% related
Robot
103.8K papers, 1.3M citations
71% related
Rotation
84.2K papers, 599.6K citations
68% related
Finite element method
178.6K papers, 3M citations
68% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023104
2022235
2021173
20201,029
20191,981
20183,674