An example of a pulley system.

Applied Mechanics

An example of a pulley system.

Atwood's machine illustrates the effects of force in producing motion.

Atwood's Machine

Atwood's machine illustrates the effects of force in producing motion.

"A Block is a pulley or a system of pulleys rotating on a pintle mounted in its frame or shell with its band and strap. There are many kinds of blocks, as a pulley block, a fiddle block, a fish block, a fly block, a heart block, a hook block, etc. A block and tackle is the block and the rope rove through it, for hoisting or obtaining a purchase."—(Charles Leonard-Stuart, 1911)

Block and Tackle

"A Block is a pulley or a system of pulleys rotating on a pintle mounted in its frame or shell with…

"Combinations of pulleys are made in great variety. In the forms most commonly used, one continuous cord passes around all the pulleys. Frequently two or more sheaves are mounted in the same block and turn on the same axis, as in the common block and tackle." — Avery, 1895

Block and tackle

"Combinations of pulleys are made in great variety. In the forms most commonly used, one continuous…

"A combination of fixed and immovable pulleys, employed to secure what engineers call a large 'mechanical edge.'"

Block and tackle

"A combination of fixed and immovable pulleys, employed to secure what engineers call a large 'mechanical…

"If the number of ropes be increased, the weight may be increased with the same power; or the power may be diminished in proportion as the number of ropes is incrased." -Comstock 1850

Compound Pulley

"If the number of ropes be increased, the weight may be increased with the same power; or the power…

"...there is a system of pulleys represented, in which the weight is sixteen times the power." -Comstock 1850

Compound Pulley

"...there is a system of pulleys represented, in which the weight is sixteen times the power." -Comstock…

"Compound pulleys using one fixed and two moveable pulleys to pull a weight up by applying a downward force." -Avery 1895

Compound Pulley

"Compound pulleys using one fixed and two moveable pulleys to pull a weight up by applying a downward…

"Compound pulley designed to use very little power to lift heavy weights." -Avery 1895

Compound Pulley

"Compound pulley designed to use very little power to lift heavy weights." -Avery 1895

"In the differential pulley, an endless chain is reeved upon a solid wheel that has two grooved rims and is carried in a fixed block above, and upon a pulley below." — Avery, 1895

Differential Pulley

"In the differential pulley, an endless chain is reeved upon a solid wheel that has two grooved rims…

An illustration of a dumb waiter which is a moveable frame in a shaft which is suspended by a rope on a pulley. Dumb waiters are a smaller version of an elevator.

Dumb Waiter

An illustration of a dumb waiter which is a moveable frame in a shaft which is suspended by a rope on…

This medieval elevator shows the use of two simple machines: wheel and axle on the right, and a pulley on the left. "An elevator of the Middle Ages. History tells us this form of elevator was used in monasteries for hoisting passengers and supplies." -Hill, 1921

Early Elevator

This medieval elevator shows the use of two simple machines: wheel and axle on the right, and a pulley…

Woman using pulleys.

Exercise

Woman using pulleys.

Woman using pulleys.

Exercise

Woman using pulleys.

Woman using pulleys.

Exercise

Woman using pulleys.

"A moveable pulley is seldom used alone. It is generally combined with a fixed pulley, as shown [here]." —Quackenbos 1859

Fixed and Moveable Pulley

"A moveable pulley is seldom used alone. It is generally combined with a fixed pulley, as shown [here]."…

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and tuning on an axis carried in a frame, called a pulley block. The pulley is fixed if the block is stationary." — Avery, 1895

Fixed Pulley

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and tuning on an axis carried…

"A fixed pulley is one whose block is not movable. In this case, if the weight W be lifted by pulling down P, the other end of the cord W will evidently move the same distance upwards that P moves downwards; hence, P must equal W." — Hallock, 1905

Fixed Pulley

"A fixed pulley is one whose block is not movable. In this case, if the weight W be lifted by pulling…

"[This illustration] represents a fixed pulley. The block is attached to a projecting beam. P is the power, and W the weight. For every inch that P descends, W ascends the same distance." —Quackenbos 1859

Fixed Pulley

"[This illustration] represents a fixed pulley. The block is attached to a projecting beam. P is the…

"In machinery, a form of slip-coupling applied in cases where the variations of load are sudden and great, as in dredging-machinery, etc. In the form illustrated a strong pulley, B, is keyed on the driving-shaft, and on the circumference of this wheel, A, is fitted, with a series of friction-plates, a, a, a, interposed, and retained in recesses formed in the eye of the wheel." -Whitney, 1911

Friction Wheel

"In machinery, a form of slip-coupling applied in cases where the variations of load are sudden and…

"GIN-BLOCK. A simple form of tackle-block with a single wheel, over which a rope runs. It has a hook by which it swings from the jib of a crane or the sheer of a gin." -Whitney, 1911

Gin-Block

"GIN-BLOCK. A simple form of tackle-block with a single wheel, over which a rope runs. It has a hook…

A lifting hook is a device used for grabbing and lifting loads by means of a device such as a hoist or crane. Lifting hooks are usually equipped with a safety latch to prevent the disengagement of the lifting wire rope sling, chain or rope to which the load is attached. Hooks may have one or more built in pulleys to amplify the lifting force.

Safety Purpose Lifting Hook

A lifting hook is a device used for grabbing and lifting loads by means of a device such as a hoist…

"Part of Lapidary's Mill. A, upper summer (cut through); B, lower summer (cut through); C, spindle; D, pulley; E, lap; F, table (cut through); g, g, wooden blocks, adjusted by means of wedges." —The Encyclopedia Britannica, 1910

Lapidary's Mill

"Part of Lapidary's Mill. A, upper summer (cut through); B, lower summer (cut through); C, spindle;…

"In straight levers of the first kind, the fulcrum is between the power and the resistance, as in fig 1, where F is the fulcrum of the lever AB; P is the power, and W the weight or resistance."—Pettigrew, 1874

First Kind of Lever

"In straight levers of the first kind, the fulcrum is between the power and the resistance, as in fig…

A fixed pulley. It is called such because the block is attached to the ceiling and cannot move.

Simple Machine

A fixed pulley. It is called such because the block is attached to the ceiling and cannot move.

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and turning on an axis carried in a frame, called a pulley block. The pulley is movable if the block moves during the action of the power." — Avery, 1895

Movable pulley

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and turning on an axis…

"A movable pulley is one whos block is movable. One end of the cord is fastened to the beam, and the weight is sspended from the pulley, the other end of the cord being drawn by the application of a force P. A little consideration will show that if P moves through a certain distance, say 1 foot, W will move through half that distance, or 6 inches; hence, a pull of 1 pound at P will life 2 pounds at W." — Hallock, 1905

Movable Pulley

"A movable pulley is one whos block is movable. One end of the cord is fastened to the beam, and the…

"[This illustration] represents a moveable pulley. A is the wheel. One end of the rope is fastened to a support at D, while the power is applied to the other at P." —Quackenbos 1859

Moveable Pulley

"[This illustration] represents a moveable pulley. A is the wheel. One end of the rope is fastened to…

"System of moveable pulleys. Each pulley has a separate rope attached to a fixed support at one end." —Quackenbos 1859

Movable Pulleys

"System of moveable pulleys. Each pulley has a separate rope attached to a fixed support at one end."…

"When a high degree of force is required, several moveable pulleys may be combined, as represented [here]. A and B are fixed pulleys; C and D are moveable ones, from the block of which the weight W is suspended" —Quackenbos 1859

Multiple Pulleys

"When a high degree of force is required, several moveable pulleys may be combined, as represented [here].…

A wheel for transmitting power from, or imparting it to the different parts of machinery, or for changing the direction of motion by means of a belt, cord, or rope.

Pulley

A wheel for transmitting power from, or imparting it to the different parts of machinery, or for changing…

"A pulley is a grooved wheel, around which a rope is passed, and is either fixed or moveable." — Goodrich, 1844

Pulley

"A pulley is a grooved wheel, around which a rope is passed, and is either fixed or moveable." —…

"The pulley is a lever with equal arms of the first or second class, but, when it moves. the attachments of the forces are moved. The underlying fact that enables the pulley to afford any mechanical advantage is the uniformity of the tension of the cord in all of its parts, the pulley itself serving only to diminish the friction." — Avery, 1895

Pulley

"The pulley is a lever with equal arms of the first or second class, but, when it moves. the attachments…

One of the six simple machines or mechanical powers. It consists of a grooved wheel mounted in a block, and is used to increase power and transmit it, by means of a rope or flexible cord, in a changed direction.

Pulley

One of the six simple machines or mechanical powers. It consists of a grooved wheel mounted in a block,…

"[The pulley] consists of a wheel with a grooved circumference, over which a rope passes, and an axis or pin, round which the wheel may be made to turn. A represents the block, B the axis, C the wheel." —Quackenbos 1859

Pulley

"[The pulley] consists of a wheel with a grooved circumference, over which a rope passes, and an axis…

"A small wheel turning upon an axis." -Foster, 1921

Pulley

"A small wheel turning upon an axis." -Foster, 1921

A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable or belt usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Pulley

A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between…

A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable or belt usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Pulley

A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between…

A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope, cable, belt, or chain usually runs over the wheel and inside the groove, if present. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion. Two or more pulleys together are called a block and tackle.

Pulley

A pulley, also called a sheave or a drum, is a mechanism composed of a wheel on an axle or shaft that…

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable or belt usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Pulley Blocks

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel…

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable or belt usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Pulley Blocks

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel…

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel (called a sheave) with a groove between two flanges around the wheel's circumference. A rope, cable or belt usually runs inside the groove. Pulleys are used to change the direction of an applied force, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.

Pulley Blocks

An illustration of a block pulley. A pulley (also called a block) is a mechanism composed of a wheel…

An example of a pulley system.

Pulley Example

An example of a pulley system.

"A horse without machinery can not lift a weight; but he does it readily with the aid of the simple apparatus shown [here].." —Quackenbos 1859

Pulley System

"A horse without machinery can not lift a weight; but he does it readily with the aid of the simple…

A pulley, when fixed in such a way that it can only turn about a fixed axis, confers no mechanical advantage.

Pulley System

A pulley, when fixed in such a way that it can only turn about a fixed axis, confers no mechanical advantage.

This pulley arrangement gives a mechanical advantage of 2; for the lower, movable pulley may be regarded as an endless lever of the second order.

Pulley System

This pulley arrangement gives a mechanical advantage of 2; for the lower, movable pulley may be regarded…

This figure has six pulleys and one cord passes round them all. Each pulley is stretched with the same amount of force, which is equal to the power creating a mechanical advantage of 6.

Pulley System

This figure has six pulleys and one cord passes round them all. Each pulley is stretched with the same…

This arrangement have three movable pulleys, each hanging by a separate cord. The mechanical advantage is 8.

Pulley System

This arrangement have three movable pulleys, each hanging by a separate cord. The mechanical advantage…

"Many wheels may be combined together, and in many ways, to form compound pulleys. Whenever there is but one rope running through the whole, as shown here, the relation of power and resistance is known by the number of folds, or turns, of the rope which supports the weight." — Goodrich, 1844

Compound pulley

"Many wheels may be combined together, and in many ways, to form compound pulleys. Whenever there is…

An illustration of an inclined plane pulley. "Let the weight w be started to move p the plane, and let P be the pull in the cord which just keeps up steadily the motion imparted to w. Then id l is the length of the plane and h its vertical height, it is evident that when w rolls the whole distance l, P falls through the same distance since the length of l of cord passes over the pulley." -Britannica, 1891

Incline Plane Pulley

An illustration of an inclined plane pulley. "Let the weight w be started to move p the plane, and let…

"The belt is thrown on to set the machine in motion, the loose pulley is pressed aside by the spiral springs on the bolts, its rim entirely touches that of the fast pulley and helps to set this latter in motion by friction." —Grimshaw, 1902

Loose Driving Pulley

"The belt is thrown on to set the machine in motion, the loose pulley is pressed aside by the spiral…

A pulley is a mechanism of a wheel on an axle or shaft that may have a groove between two flanges around its circumference. A rope usually runs over the wheel and inside the groove, if present.

Sash Pulley

A pulley is a mechanism of a wheel on an axle or shaft that may have a groove between two flanges around…

"Pulleys designed to allow the weight to be pulled up while the power is applied downwards." -Avery 1895

Pulleys

"Pulleys designed to allow the weight to be pulled up while the power is applied downwards." -Avery…

These pulleys are grooved such as to guide the inner belt, in this system there is less of a chance that a belt will run out of the pulley.

Grooved Pulleys

These pulleys are grooved such as to guide the inner belt, in this system there is less of a chance…

Egyptians using pulleys to build a pyramid.

Building the Pyramids

Egyptians using pulleys to build a pyramid.

Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Simple Machines

Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge,…

"...represents a simple pulley, with a single fixed wheel. In other forms of the machine, the wheel moves up and down with the weight." -Comstock 1850

Simple Pulley

"...represents a simple pulley, with a single fixed wheel. In other forms of the machine, the wheel…

"Two fixed pulleys used to raise W." -Comstock 1850

Simple Pulley

"Two fixed pulleys used to raise W." -Comstock 1850

"In the single moveable pulley, the same rope passes from the fixed point, A, to the power, P. It is evident here, that the weight, W, ten pounds, five pounds will be supported by one string, and five by the other. The power will then support twice its own weight." -Comstock 1850

Single Movable Pulley

"In the single moveable pulley, the same rope passes from the fixed point, A, to the power, P. It is…

"A block used in ships, having an opening in one side to receive the bight of a rope, chiefly used for heavy purchases, where a warp or hawser is brought to the capstan." — Williams, 1889

Snatch-block

"A block used in ships, having an opening in one side to receive the bight of a rope, chiefly used for…