How to use Pulley in a sentence
The strap is usually of iron, and the pulley of hard wood.
A recording drum or integrating apparatus may be arranged on the pulley frames.
It works in conjunction with the disk and scroll, the cones, or the expanding pulley, to impart an intermittingly variable speed to the bobbin (each layer of the bobbin has its own particular speed which is constant for the full traverse, but each change of direction of the builder is accompanied by a quick change of speed to the bobbin).
When the cones are pressed together or engaged, their friction causes the pulley to rotate along with the shaft; when they are disengaged, the pulley is free to stand still.
Friction of Cords and Belts.A flexible band, such as a cord, rope, belt or strap, may be used either to exert an effort or a resistance upon a pulley round which it wraps.Advertisement
The pulley E is driven from an axle of the carriage.
She had not yet gone to bed when the Rostovs arrived and the pulley of the hall door squeaked from the cold as it let in the Rostovs and their servants.
Arising as a long tendon from the sterno-scapular ligament, it passes the axilla by means of a fibrous pulley, accompanies the axillary vessels and nerves along the humerus, and is inserted by a few fleshy fibres on the base of the last two or three cubital quills.
The tail rope, which is of lighter section than the main one, is coiled on the second drum, passes over similar guide sheaves placed near the roof or side of the gallery round a pulley at the bottom of the plane, and is fixed to the end of the train or set of tubs.
This is done by passing a loop at the upper end round a pulley mounted in a travelling frame, to which is attached a weight of about 15 cwt.Advertisement
This weight pulls directly against the rope; so if the latter slacks, the weight pulls out the pulley frame and tightens it up again.
A belt when in motion is shifted off a pulley, or from one pulley on to another of equal size alongside of it, by pressing against that part of the belt which is moving towards the pulley.
At a small distance from the pulley the shaft carries a short frustum of a solid cone accurately turned to fit the hollow cone.
The throttle-valve is opened or closed by turning a grooved vertical pulley by means of an endless cord, called the telegraph, passing round another pulley fixed upon the " headache-post," and is thus under the control of the driller working in the derrick.
At one end of the band-wheel shaft is the bull-rope pulley, and upon the other end is a crank having six holes to receive a movable wrist-pin, the length of stroke of the walking-beam being thus adjusted.Advertisement
He was said to be the inventor of a kind of flying-machine, a wooden pigeon balanced by a weight suspended from a pulley, and set in motion by compressed air escaping from a valve.'
A road maybe used as a self-acting or gravitating incline when the gradient is r in 30 or steeper, in which case the train is lowered by a rope passing over a pulley or brake drum at the upper end, the return empty train being attached to the opposite end of the rope and hauled up by the descending load.
The rope, which is guided upon sheaves between the rails, is taken twice round the head pulley.
It is also customary to use a stretching pulley to keep the rope strained when the pull of the load diminishes.
Two equal sprocket wheels Q 1, Q 2, are fastened, the one to the spring pulley, the other to the shaft.Advertisement
When a belt, in which the maximum and minimum tensions are respectively P and p lb, drives a pulley, the torque exerted FIG.
H is a pulley to guide the approaching and receding parts of the belt to and from the beam in parallel directions.
The Power Of The Brake May Be Estimated By Comparison With The Size Of The Rope Pulley Seen Behind It On The Same Shaft.
When the a,ces of a pair of pulleys are not parallel, the pulleys should be so placed that the part of the belt which is approaching each pulley shall be in the plane of the pulley.
Let Ti be the tension of the free part of the band at that side towards which it tends to draw the pulley, or from which the pulley tends to draw it; 1, the tension of the free part at the other side; T the tension of the band at any intermediate point of its arc of contact with the pulley; 0 the ratio of the length of that arc to the radius of the pulley; do the ratio of an indefinitely small element of that arc to the radius; F=TiT2 the total friction between the band and the pulley; dF the elementary portion of that friction due to the elementary arc do; f the coefficient of friction between the materials of the band and pulley.Advertisement
The equations 65 and 66 are applicable to a kind of brake called a friction-strap, used to stop or moderate the velocity of machines by being tightened round a pulley.
The builder, which receives its motion from the disk and scroll, from the cones, or from the expanding pulley, has also an intermittingly variable speed.
The power is applied by a belt round a pulley, which is mounted on the end of the horizontal shaft which carries the brushes.
Behind the pulley at the top of the machine and on the same shaft is a spur wheel, which drives both of the spur wheels shown in the diagram.
On the same axle as the drum and behind it is a small pulley which is keyed upon the axle and is connected with the small pulley (which runs idle on its shaft) at the left-hand side of the machine by a crossed belt.Advertisement
The sprocket wheel is connected by a chain with a similar sprocket wheel which is keyed on the same shaft as that of the left-hand pulley.
The dimensions of the nave depend to a large extent on the method of keying or otherwise securing the pulley to the shaft.
The pulley is in halves to facilitate fixing, and when in place the sections C are joined by plates E, bolted or riveted to the rim.
The two halves of the nave are secured by bolts or rivets passing through the flanges F, and the pulley is connected to the shaft by a sunk key or by conical keys driven in between the shaft and the boss, which latter is bored to suit.
The pulley is secured to the shaft by conical keys, to give a frictional grip on both the shaft and the pulley; these keys may have their exterior surfaces eccentric to the shaft, with corresponding recesses in the nave, so that the pulley and keys virtually form one piece.Advertisement
If the centre of gravity of a pulley is on the axis of rotation, and the whole mass is distributed so that the axis of inertia coincides with the axis of rotation, there can be no unbalanced force or unbalanced couple as the pulley revolves.
The magnitude of the unbalanced force, for a mass of w pounds at a radius of r feet and a velocity of v feet per second, is expressed by wv 2 /gr lb; and, since the force varies as the square of the velocity, it is necessary carefully to balance a pulley running at a high speed to prevent injurious vibrations.
This can be accomplished by attaching balance-weights to the pulley until it will remain stationary in all positions, when its shaft rests on two horizontal knife-edges in the same horizontal plane, or, preferably, the pulley and shaft may be supported on bearings resting on springs, and balanced by attached masses until there is no perceptible vibration of the springs at the highest speed of rotation.
The rims of pulleys, round which flat bands are wrapped, may be truly cylindrical, in which case the belt will run indifferently at any part of the pulley, or the rim may be swelled towards the centre, when the central line of the band will tend to run in the diametral plane of the pulley.
This self-guiding property may be explained by the tendency which a flat band has, when running upon a conical pulley in a direction normal to its axis, to describe a spiral path as it wraps on to the surface because of the lateral stiffness of the material; the advancing side therefore tends to rise towards the highest part of the cone.Advertisement
In practice the pulley rim is curved to a radius of from three to five times its breadth, and this not only guides the belt, but allows the line of direction of the advancing side to deviate to a small extent, depending on the elasticity of the material.
The belts are moved laterally by the forks of a striking gear pressing on the advancing sides of the belts, and the pulleys are arranged so that the belts either wrap round the loose pulleys, or can be shifted so that one wraps round a fixed pulley, while the other still remains on its loose pulley.
Motion in either direction is thereby obtained, and a considerable variation in the speed of rotation can be obtained by providing a cone pulley on the countershaft, which drives the cone pulley secured to the lathe E FIG.
When pulleys are mounted on shafts which are parallel to one another, the band will retain its position, provided that its central line advances towards each pulley in the diametral plane of this latter.
In English practice there are as many separate endless ropes as there are pairs of grooves in the two pulleys to be connected, but in cases of American practice the rope is continuously wound round the two pulleys, and the free end passes over a pulley mounted on a movable weighted carriage to adjust the tension.Advertisement
It is of considerable importance that the effective radius of action of the rope remain constant throughout each pulley, otherwise the wear on the rope becomes very great and its life is diminished.
The resistance to slipping of a flat belt on a pulley may be obtained by considering the equilibrium of a small arc of the pulley surface subtending an angle dB at the centre, and having tensions T and T+dT at its extremities.
Neglecting quantities of the second order, the pressure on the pulley is TdO, and the friction is MTd9 where p, is the coefficient of friction between the belt and the pulley.
For a single pulley of diameter D, turning on a fixed pin of diameter d, the relation of the effort E to the load W, where f is the coefficient of friction, is expressed by E/W = (D-pfd)/(D - fd) _ 1 +2fd/D approximately.
The conditions which enable a pulley tackle to sustain a weight when the effort is removed may be examined, to a first approximation, if we assume that the internal friction acts in such a way as virtually to diminish FIG.Advertisement
In order to obtain a greater ratio of R to E, without using a large number of sheaves, various arrangements are used, of which the' Weston differential pulley block is a typical example.
An endless chain B, passing through guides C and D, encircles these pulleys and the single loose pulley E of the lower block, as indicated.
In order to obtain a self-sustaining pulley tackle, which will have an efficiency of more than 50%, various arrangements are adopted, which during lifting automatically throw out of action a brake and cause it to come into action again when the effort is removed.
Standard V shape pulley with boss to fit alternator or Dynalite.
He ran a dummy generator with just a pulley to save weight as well as a one-piece aluminum bonnet and cycle front wings.
The circulating pump which cools the condenser is driven from the generator pulley system.
It looks like they could be cleared in an orderly top-down fashion using a pulley system and great care.
The 10mm bore headstock spindle used two adjustable conical hardened-steel plain bearings with a ball thrust race behind the pulley.
I t is stuck in a high position thanks to a small wedge on which a pulley adjusts the mainsheet.
The 3-step pulley together with its attached " sun " gear was free to rotate on the headstock spindle.
The drivetrain uses a 4-step pulley to give different blade speeds.
The Bergeon electric motor (with a two-step pulley) was cradled in a cast-iron holder and available with both single and three-phase motors.
Once set, make an easier to see mark on the rear timing cover above the crank pulley aligned with the scribed timing mark.
An adjustable pulley is fitted to allow small variations for on-site balancing.
The pulley wheels attach to pulley wheels attach to pulley stiles - the upright sides of the frame which hide the weights.
The three rings of indexing holes in the headstock pulley were engaged by a pointer mounted on a swinging bracket.
Above the crankshaft pulley, the oil pump sprouts from the block, a necessity to keep the overhead valve gear from seizing up.
Once the tensioner has been removed, check the tensioner pulley.
There have been no recorded instances of the alternator pulley seizing on vehicles in the UK.
The main drive pulley was 4.25 " in diameter and the rear idler pulleys, running on ball bearings, 3.5 " .
From the basic knots through to pulley systems and crevasse rescue.
Make sure you sit far enough away from the pulley, to prevent the cable rubbing against your right leg.
Available as extras were an electric motor with a drive pulley, a round foot stand for bench mounting and a lever-action tailstock.
Has anybody out there got a vintage tractor or two with a pulley to power up the big bench for a weekend?
If a pound weight be suspended by a string passing over pulley, in descending through io ft.
On the anterior side of the tibia, is the intercondylar sulcus, which is crossed by an oblique bridge of tendon or bone, acting as a pulley for the tendon of the extensor digitorum communis muscle.
At that moment they heard the sound of the door pulley and footsteps in the hall and anteroom, as if someone had arrived.
The main drive pulley was 4.25 " in diameter and the rear idler pulleys, running on ball bearings, 3.5 ".
The pulley wheels attach to pulley stiles - the upright sides of the frame which hide the weights.
You can easily verify which you have by simply looking at the pulley bolt head.
Again it is advisable to use rotten bottom pulley rigs here to minimize tackle losses.
The countershaft pulley shaft was fitted with self-aligning ball bearings and provision was made to allow individual adjustment of each belt run.
Block Rope Used with a pulley block to increase the power of a horse pulling a boat out of a lock.
A traverse curtain rod has a pulley system that allows you to open and close your drapes using a cord.
This system lifts the chairs on a pulley and fast moving cable.
Some manual awnings are controlled by a rope and pulley system.
The strongest form of traction involves inserting a stainless steel pin through a bony prominence attached by a horseshoe-shaped bow and rope to a pulley and weights suspended over the end of the patient's bed.
Slide the other end of the belt over the metal pulley that guides the belt.
Standing Cable Pressdowns (aka Pushdowns) - Face a cable machine with a short handle attached to the upper pulley.
Cable External Rotator Pulls - Move the pulley to about waist-high on a cable machine and attach a single handle.
There's an up-front cost of buying a bench with a pulley attachment, barbell, dumbbells and some plates, but that's it -- no annual fees or cost of transportation to and from a gym.
Grab a thick rope attached to the lower cable pulley and hold it like you'd hold two hammers.
Attach a thick rope with good-sized end-stops to the upper pulley of a cable machine.
Kneel in front of a cable machine with a thick rope attached to the upper pulley.
At the gym, you can do a standing crunch using a rope on a high cable pulley.
You can also do this exercise with a high cable pulley machine.
The Winsor Pilates Accelerator is like a portable cable pulley machine that you can use at home.
The smoother we make the pulley the more nearly does the amount of useful work which the weight is capable of doing approach ro foot-pounds, and if we take into account the work done against the friction of the pulley, we may say that the work done by the descending weight is ro foot-pounds, and hence when the weight is in its elevated position we have at disposal r o foot-pounds more energy than when it is in the lower position.
The band-wheel communicates motion to the walking-beam, while drilling is in progress, through the crank and a connectingrod known as the pitman; to the bull-wheels, while the tools are being raised, by the bull-rope; and to the sand-pump reel, by a friction pulley, while the sand-pump is being used.
In dip workings the tail rope is often made to work a pump connected with the bottom pulley, which forces the water back to the cistern of the main pumping engine in the pit.
The change in the distance d is proportional to the change in the torque transmitted from the shaft to the pulley.
Q is supplied by a spring, the extensions of which are recorded on a drum driven proportionally to the angular displacement of the driving pulley; thus a work diagram is obtained.
A torque applied to the shaft A can be transmitted to D, neglecting friction, without change only if the central pulley K is held from turning; the torque required to do this is twice the torque transmitted.
The pulley or sheave FG has a weight W
A rotating shaft carries upon a cylindrical portion of its figure a wheel or pulley turning loosely on it, and consequently capable of remaining at rest when the shaft is in motion.
This pulley has fixed to one side, and concentric with it, a short frustum of a hollow cone.
In the friction-clutch, a pulley loose on a shaft has a hoop or gland made to embrace it more or less tightly by means of a screw; this hoop has short projecting arms or ears.
When the clutch is moved towards the hoop, its arms catch those of the hoop, and cause the hoop to rotate and to communicate its rotation to the pulley by friction.
When the load to be weighed comes upon the platform, the end of the steelyard rises and unlocks the ratchet wheel through the pawl; the sprocket gearing is driven by the friction clutch, and drives the axle of the left-hand small pulley.
When the poise arrives at zero it frees the clutch which connects the pulley and the sprocket wheel, and the machine is then ready for the next load.
A pulley carried on a rotating shaft and connected to another pulley on a second shaft by an endless band consisting of a flat belt, rope, chain or similar connector serves for the transmission of power from the one shaft to the other and is known as a driving pulley; while combinations of pulleys or "sheaves," mounted in fixed or movable frames or "blocks," constitute mechanisms used to facilitate the raising of heavy weights.
The rim is also subject to a centrifugal tension of amount wv 2 /g pounds per square inch of section, where w is the weight in pounds of a length of one foot of the pulley rim one square inch in section, and v is the velocity of the rim in feet per second.
The forward feed is given by a chain winding upon a drum, which hauls upon a pulley fixed to a prop about 30 yds.
A flexible steel band, lined with wood blocks, is gripped on the motor fly-wheel or pulley by a screw A, which, together with W, is adjusted to hold the brake steady.
The band turns with the fast pulley if µ increase, thereby slightly turning the loose pulley, otherwise at rest, until 0 is adjusted to the new value of µ.
The salt is conveyed to the furnace by a chain of buckets running on the pulley (g), and passing into the hopper (h), and through the pipe (i) is mixed with the proper amount of acid supplied by the pipe (f).
In either case the tangential force, whether effort or resistance, exerted between the band and the pulley is their mutual friction, caused by and proportional to the normal pressure between them.
The work lost in pulling a given length of rope over a pulley is found by multiplying the length of the rope in feet by its stiffness in pounds, that stiffness being the excess of the tension at the leading side of the rope above that at the following side, which is necessary to bend it into a curve fitting the pulley, and then to straighten it again.
In Koepe's method the drum is replaced by a disk with a grooved rim for the rope, which passes from the top of one cage over the guide pulley, round the disk, and back over the second guide to the second cage, and a tail rope, passing round a pulley at the bottom of the shaft, connects the bottoms of the cages, so that the dead weight of cage, tubs and rope is completely counterbalanced at all positions of the cages, and the work of the engine is confined to the useful weight of coal raised.
A belt tends to move towards that part of a pulley whose radius is greatest; pulleys for belts, therefore, are slightly swelled in the middle, in order that the belt may remain on the pulley, unless forcibly shifted.
The effective radius, or radius of the pitch-circle of a circular pulley or drum, is equal to the real radius added to half the thickness of the connector.
The three middle metatarsals become fused together into a cannon bone; the upper part of the third middle metatarsal projects behind and forms the so-called hypotarsus, which in various ways, characteristic of the different groups of birds (with one or more sulci, grooved or perforated), acts as guiding pulley to the tendons of the flexor muscles of the toes.
One, the quadratus or bursalis muscle, arises from the hinder surface of the eyeball, and forms with its narrow margin, which is directed towards the optic nerve, a pulley for the long tendon of the pyramidalis muscle.
The chain passes over a pulley driven by the engine, placed at such a height as to allow it to rest upon the tops of the tubs, and round a similar pulley at the far end of the plane.