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.
A recording drum or integrating apparatus may be arranged on the pulley frames.
Then to the paying-out drum P, from it to the dynamometer D, and finally to the stern pulley, over which it passes into the sea.
The strap is usually of iron, and the pulley of hard wood.
At a small distance from the pulley the shaft carries a short frustum of a solid cone accurately turned to fit the hollow cone.
At that moment they heard the sound of the door pulley and footsteps in the hall and anteroom, as if someone had arrived.
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.
It is also customary to use a stretching pulley to keep the rope strained when the pull of the load diminishes.
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.
The pulley E is driven from an axle of the carriage.
Two equal sprocket wheels Q 1, Q 2, are fastened, the one to the spring pulley, the other to the shaft.
A tuning-fork or a bell-glass, a silk or cotton thread, the other extremity being either fixed or passing over a pulley and supporting weights by which the thread may be stretched to any degree required.
In.; the governor is carried within the driving pulley shown at the right-hand end, while the working revolving cylinders are carried inside the boxed-in flywheel at the left-hand end, the relay cylinder and its attachments being fixed to the bed-plate in front of the flywheel.
Below the surface of the field is the churras, or large leather bag, suspended to a rope passing over a pulley, and raised by a pair of bullocks which go up and down a slope as long as the depth of the well.
Suppose the base-circles to be a pair of circular pulleys connected D~ ill by means of a cord whose course ~f from pulley to pulley is P1IP2.
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.
The pitch-line of a pulley or drum is a curve to which the line of connection is always a tangentthat :s to say, it is a curve parallel to the acting surface of the pulley or drum, and distant from it by half the thickness of the wrapping con nector.
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.
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.
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.
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.
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).
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 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.
In diameter, passing from the bull-wheel shaft over a grooved wheel known as the crown-pulley, at the summit of the derrick.
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.'
The astragalus has a pulley-like surface above for articulation into the tibia, but its lower surface is flattened and unites to a much greater extent with the navicular than with the cuboid, which bone is of comparatively less importance than in the Artiodactyles.
1070 I 060 960 950 930 911 889 883 858 825 823 810 781 771 753 745 727 722 705 681 668, of squares and cubes, calculated from 1 to 60, have been found at Senkera, and a people who were acquainted with the sun-dial, the clepsydra, the lever and the pulley, must have had no mean knowledge of mechanics.
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 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 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.
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.
This weight pulls directly against the rope; so if the latter slacks, the weight pulls out the pulley frame and tightens it up 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 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.
' To measure this, guide pulleys are placed in the loops guided by a geometric slide, the one pulley carrying a scale, and the other an index.
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.
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.
The wheel D, keyed to the shaft overcoming the resistance to be measured, is driven from wheel N by two bevel wheels L, L, carried in a loose pulley K.
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.
Passes over two edges AB, which serve as the fixed ends, and then over a pulley P, being stretched by a weight W.
Their lower articular surfaces, instead of being pulley-like, with deep ridges and grooves, as in other Artiodactyla, are simple, rounded and smooth.
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).
The Power Of The Brake May Be Estimated By Comparison With The Size Of The Rope Pulley Seen Behind It On The Same Shaft.
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 pulley or sheave FG has a weight W
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.
The following empirical formulae for the stiffness of hempen ropes have been deduced by Mono from the experiments of Coulomb: Let F be the stiffness in pounds avoirdupois; d the diameter of the rope In inches, fl = 48d2 for white ropes and 35d2 for tarred ropes; r the effectire radius of the pulley in inches; T the tension in pounds.
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.
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.
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.
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.
Effected by the pulley drawing in or letting out a part of the band or rope which has been roughened or in which a knot has been tied.
Trans., 1894) investigated the question for the cases of loaded and unloaded shafts, and, owing to the complication arising from the application of the general theory to the cases of loaded shafts, devised empirical formulae for the critical speeds of shafts loaded with heavy pulleys, based generally upon the following assumption, which is stated for the case of a shaft carrying one pulley: If Ni, N1 be the separate speeds of whirl of the shaft and pulley on the assumption that the effect of one is neglected when that of the other is under consideration, then the resulting speed of whirl due to both causes combined may be taken to be of the form N1N2~!
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.
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.