INTRODUCTION

Types of Vertical Transportation systems

Stairs Ramps Escalators Elevators/ Lifts

Elevator

An elevator by definition is a platform or an enclosure raised and lowered in a vertical shaft to transport people and freight.

HISTORY

It all began with the hoist. In ancient times, it is used to draw water or raise building materials hoists must have played a fundamental role in the construction of the great pyramids of Egypt. The first documented proof of their use, however, comes from Greece, in 236 B.C., when Greek mathematician,

physicist and inventor Archimedes invented a hoist device with rope and pulley, whereby a hoist rope was wrapped around a capstan and manpower used to pull a lever to turn the drum. These were first used in the Roman Emperor Nero’s palace.

Hoists using human workers as counterweights Emperor Napoleon built a caged chair so that the Empress could ascend staircases without effort.

The mid 19th century marked the dawning of the age of electricity

first high-rise buildings in the United States, which necessitated the development of elevators in order to make them practical

in 1853, when Elisha Graves Otis solved the problem of rope failure He installed a rope-break safety device called the safety brake (the equivalent of the modern safety gear) in England, Frost and Stutt successfully developed a counterbalance-type, traction-method elevator called the

“Teagle”, in 1853 The world’s first passenger service elevator was installed in a five-story hotel on Broadway in New York, in

1857. Manufactured by the Otis Elevator Companyo 12 meters per minute (39.4 ft./min.)

In 1867, the practicality of the hydraulic-power elevator was recognized when Leon Edoux exhibited one at the Paris Exposition

o 150 meters per minute (492 ft./min.) hydraulic-power elevators began appearing in 1878, and became widely used in Europe and the United States. The first person to use a DC motor for an elevator is believed to be Wegster in 1884 in the United States. in 1889, Norton Otis, son of the pioneering Elisha, developed an electric elevator, the first direct-connected

geared elevator in the world, and installed it in the Demarest Carriage Building on Fifth Avenue in New York. The elevator carried a load of 675 kilograms and topped out at a speed of 30 meters per minute

Oil-power hydraulic elevators were installed in the Eiffel Tower, the symbol of the Paris Exposition in 1889

1903, the traction type current elevator models appeared in the United States. 1922, Westinghouse installed a gearless elevator in the Physical Education Building in Chicago

o 420 meters per minute In the 1930s, against a backdrop of some 75 years of elevator technology development, which served to drive

the construction and practical application of skyscrapers soaring as high as 102 stories, Mitsubishi Electric Corp. entered the elevator business.

Over the next 75 years- way for today’s elevators which can reach speeds as fast as 1,000 meters per minute

DEFINITION OF TERMS

• penthouse- a structure housing elevator machinery on the roof of a building

• bulkhead- a boxlike structure on a roof providing access to a stairwell or an elevator shaft.

• control panel- a panel containing switches ,button, and other equipment for regulating electrical devices.

• elevator pit- the portion of a hoistway extending from the level of the lowest landinf to the floor of the hoistway

• bottom car clearance- the vertical distance from the floor of an elevator pit to the lowest part of an elevator car platform when the car rests on fully compressed buffers.

• buffer- a piston or spring device for absorbing the impact of a descending elevator car or counterweight at the extreme lower limit of travel.

• limit switch- a switch that automatically cuts off current to an electric motor when an object moved by it, as an elevator car, has passed a given point.

• counterweight- a weight balancing another weight, as the rectangular cast-iron blocks mounted in a steel frame to counterbalance the load placed on the hoisting machine by an elevator car.

• hoistway- a vertical enclosed space for hte travel of one or more elevators. also called elevator shaft.

• traveling cable- one of the electric cables connecting an elevator car to a fixed electrical outlet in the hoistway.

• guide rail- one of the vertical steel tracks controlling the travel of an elevator car or counterweight.

• machine beam- one of the heavy steel beams supporting the hoisting machinery for an elevator.

• hoisting cable- one of the wire cable or ropes used for raising and lowering an elevator car.

• idle sheave- a pulley for tightening and guiding and guiding the hoisting cables of an elevator system. also called deflector sheave.

• driving sheave-a wheel or disk with a grooved rim, used as a pulley for hoisting.

• hoisting machinery-the machinery for raising and lowering an elevator car, consisting of a motor generator set, traction machine, speed governor, brake, drive shaft, driving sheave, and gears if used.

• elevator car safety- a mechanical device for slowing down and stopping an elevator car in the eventt of excessive speed or free fail, actuated by a governor and clamping the guide rails by a wedging action.

• hoistway door- a door between a hoisway and an elevator landing, normally closed except when an elevator car is stopped at the landing.

TYPES OF ELEVATOR ACCORDING TO USE

Handicap Elevatorso used in smaller or limited access buildings where installation of a full-sized elevator isn't possibleo smaller than traditional elevators, at 18 square feet, 3'6" wide, and 5' deepo come with safety features, including an emergency light and alarm, handrails, and a battery powered

descent in the event of a power failure Wheelchair Lift

o also known as a platform lift, or vertical platform lift o raise a wheelchair and its occupanto an alternative to a stair lift

Grain Elevatorso bucket elevator or a pneumatic conveyoro scoops up grain from a lower level and deposits it in a storage facilityo the term "grain elevator" also covers the entire elevator complex

Double-deck Elevatorso two cars attached together, one on top of the othero The elevator serving even floors is actually on top of the elevator serving odd floors in the same lift shafto occupy less building core space than traditional single-deck elevators do for the same level of traffic

Sky Lobbyo used in high-rise buildings, such as skyscrapers, to make travel between elevators convenient for all

passengerso most such buildings have one elevator, called an express elevator, which only travels between the different

sky lobby floors

TYPES OF ELEVATORS ACCORDING TO MECHANISM

-HYDRAULIC ELEVATOR

-TRACTION ELEVATOR

Hydraulic Elevator powered by a piston that travels inside a cylinder. limited to heights of about 60 ft. (6 stories) lower speed lower initial cost - higher power consumption

types of hydraulic elevatorholed hydraulic

In-ground cylinder extends to a depth equal to the rise of the elevator cab. Current codes require double-bottom cylinders with leak detection and containment.

holeless hydraulic use a telescoping hydraulic piston as the driving machine, eliminating the need of an in-ground cylinder.

limited to height of 3 stories

roped hydraulic use a telescoping hydraulic piston and a hoist rope and pulley system to increase speed

and travel heights

Machine room less hydraulic does not require a fixed room to house the hydraulic machinery, the machinery itself is usually installed on the elevator pit controller is installed behind a locked cabinet on the wall near the elevator

Benefits of Hydraulic Elevators

No need for reinforcement. The cylinder that lifts the elevator cab is supported by the ground underneath.

Are usually cheaper than traction units.

If the line breaks, the elevator will fall no faster than oil can escape.

Detriments of Hydraulic Elevators

risk of leaking hydraulic oil into an aquifer and causing potential environmental contamination.

ELEVATOR COMPONENTS

-HOISTWAYS

-MACHINES

-CABS

Hoistway

enclosed by fireproof walls and elevator doors includes the pit and terminates at the underside of the overhead machinery space floor or at the underside of

the roof where the hoistway does not penetrate the roof also called "hatchway" or "hatch" the shaft that encompasses the elevator car. A blind hoistway has no doors on the floors that it does not serve.

Hoistway components:

Guide rails for both the car and counterweight.o Guide rails are steel tracks in the form of a “T” that run the length of the hoistway, round, or formed

sections with guiding surfaces to guide and direct the course of travel of an elevator car and elevator counterweights and usually mounted to the sides of the hoistway.

o Combined Bracket Combined bracket is used only when the arrangement of the lift equipments (Car and Counterweight)

are too closed and perpendicular to each other in a specific point. o Combination Bracket

Counterweighto Counterweight is a tracked weight that is suspended from cables and moves within its own set of guide rails

along the hoistway walls. o Counterweight components

Top Part Assembly Bottom Part Assembly Vertical Profile Filler Weights Guide Shoes

Suspension Ropeso Suspension Ropes are suspension means for car and counterweight, which are represented by steel wire

ropes.

o They are used on traction type elevators, usually attached to the crosshead and extending up into the machine room looping over the sheave on the motor and then down to the counter weights.

o Hoisting cable are generally 3 to 6 in number. These ropes are usually 1/2”or 5/8” in diameter. o The term Roping system can be defined as the arrangement of cables supporting the elevator and which has

many types or arrangements as follows: Single wrap: rope passes over sheave once and connected to counterweight. Double wrap: rope wound over sheave twice in high speed elevators for additional traction. 1:1 roping: when rope connected to counterweight where cable travels as far as car in opposite

direction. 2:1 roping: rope wraps sheave on counterweight and connects to top of the shaft, rope moves twice as

far as cab.

Landing (Hoistway) Doorso The door that is seen from each floor of a building is referred to as the outer or hoistway dooro Hoistway Door Types

Automatic door: Center opening doors consist of two power operated panels that part simultaneously with a brisk, noiseless motion.

Swing door: Consists of a hoistway door that is manually opened and a single slide car door that is power operated.

Telescopic door: It consists of two power operated panels that are geared together. One door moves twice as fast as the other door so that both doors will meet concurrently in the open position.

Collapsible gate: Constructed from double channel rolled pickets 16mm wide x 2.5mm thick interconnected by 6mm thick galvanized steel solid lattice bars.

Hoistway Door Interlocko The hoistway door locking mechanism provides a means to mechanically lock each hoistway door. They are

also interconnected electrically to prevent operation of the elevator if any of the elevator’s hoistway doors are open.

Hoistway Emergency Door Keyso Hoistway Emergency Door Keys permit the unlocking of the hoistway door interlock.

Escutcheon Tubeo The keyhole on the upper portion of a hoistway door that accepts a hoistway emergency door key and

permits unlocking of the hoistway door locking mechanism.

Buffers In The Pit

o A Buffer is a device designed to stop a descending car or counterweight beyond its normal limit and to soften the force with which the elevator runs into the pit during an emergency. They may be of polyurethane or oil type in respect of the rated speed.

o There are two principal types of buffers in existence Energy accumulation: accumulate the kinetic energy of the car or counterweight. Energy dissipation: dissipate the kinetic energy of the car or counterweight.

MACHINES

Driving machine, this is the power unit of the elevator, and usually located at the elevator machine room.

The Driving machine used to refer to the collection of components that raise or lower the elevator. These include the drive motor, brake, speed reduction unit, sheaves and encoders.

Gearless Machine

• It used in high-rise applications whereby the drive motor and drive sheave are connected in line on a common shaft, without any mechanical speed reduction unit located between the drive motor and drive sheave.

• Generally, Gearless machines are used for high speed lifts between 2.5 m/s to 10 m/s and they can be also used for lower speeds for special applications.

• Their sizes and shapes vary with load, speed and manufacture but the underlying principles and components are the same.

Geared Machine

• It used in low and mid-rise applications. This design utilizes a mechanical speed reduction gear set to reduce the rpm of the drive motor (input speed) to suit the required speed of the drive sheave and elevator (output speed).

• Generally, geared machines are used for speeds between 0.1 m/s and 2.5 m/s and are suitable for loads from 5 Kg up to 50,000 Kg and above.

• Their sizes and shapes vary with load, speed and manufacture but the underlying principles and components are the same.

Drum Machine

• A drum design has one end of the suspension rope affixed to the inside of the winding drum’s drive sheave, and then allows to rope to reel in or off the outer surface of its sheave, depending upon the car direction of travel.

ELEVATOR CAB

Elevator Car is the vehicle that travels between the different elevator stops carrying passengers and/or goods, it is usually A heavy steel frame surrounding a cage of metal and wood panels.

Standard elevator car/cabin can be classified according to the number of entrances and their locations as follows:

• Normal Cabin

• Open Through Cabin

• Diagonal Cabin

ELEVATOR CAR COMPONENTS

• Car Sling -a metal framework connected to the means of suspension

• Elevator Cabin – the inside of the car/cab that carries the passengers

• Mechanical accessories – that includes the cab door, door operator, and protective devices.

How Elevators work UP and DownThere are two major elevator designs in common use today: hydraulic elevators and roped elevators.Hydraulic Elevators

Hydraulic elevator systems lift a car using a hydraulic ram, a fluid-driven piston mounted inside a cylinder.

The cylinder is connected to a fluid-pumping system

The hydraulic system has three parts:

A tank (the fluid reservoir)

A pump, powered by an electric motor

A valve between the cylinder and the reservoir

how it works:

The pump forces fluid from the tank into a pipe leading to the cylinder.

The valve opens or closes that controls the direction of fluid from tank.

As the fluid collects in the cylinder, it pushes the piston up, lifting the elevator car.

When the car approaches the correct floor, the control system sends a signal to the electric

motor to gradually shut off the pump.

To lower the car, the elevator control system sends a signal to the valve

The weight of the car and the cargo pushes down on the piston, which drives the fluid into the

reservoir

The Cable SystemThe most popular elevator design is the roped elevator. In roped elevators, the car is raised and lowered by

traction steel ropes rather than pushed from below.

how it works:

The ropes are attached to the elevator car, and looped around a sheave (3)

The sheave is connected to an electric motor 

the sheave, the motor and the control system (1) are all housed in a machine room above the

elevator shaft.

The ropes that lift the car are also connected to a counterweight (4), which hangs on the other side of

the sheave.

Both the elevator car and the counterweight ride on guide rails (5) along the sides of the elevator shaft.

Design considerations in Elevator systems

No. of lifts and handling capacityo Number of floors to be served by the life’ Floor to floor distanceo Population at each floor to be serve. Maximum and peak demand

Preliminary Lift planning Coordination with lobby, stairway & corridor Fire & safety regulations Handling capacity (quantity of service) Interval or waiting time (quality of service) Consideration by lift functions Population Quantity of Service Quality of Service Traffic peak Capacity

o The minimum size of car recommended for a single purpose buildings is one suitable for a duty load of 884 kg. Generally, for large office buildings cars with capacities upto 2040 kg are recommended according to the requirements.

Speed Layout

ELEVATOR INNOVATIONS

• ELEVATOR SAFETY BREAK

• Otis' invention, for which he received this patent in 1861, virtually eliminated elevator falls. The device relied on a set of loaded springs that would automatically press downward-facing hooks into upward-facing metal teeth on the sides of the elevator shaft if tension on the rope was released.

• ELECTRIC DRIVEN ELEVATOR

• Inventor: Werner von Siemens

• With a motor mounted on the bottom of the cab, Siemens’ electric elevator used a gearing system to climb wall shafts fitted with racks.

• AUTOMATIC DOORS

• In 1944 Joseph Giovanni of United Elevator Service patented a sensitive door bumper as a way to automatically stop when the elevator door hits an obstruction.

• Elevator companies like Mitsubishi Electric have since incorporated infrared and ultrasound sensors along with pressure-sensitive safety edges.

• MICROPROCESSOR-CONTROLLED ELEVATORS

• In 1979, Otis introduced the Elevonic 101 , which used a TI-99 microprocessor to control where the elevator stopped and when.

• It also automated stops, starts, and the elevator's speed, and further reduced the need for dedicated elevator operators.

• DOUBLE-DECK ELEVATORS

• Double-deck elevators are designed to optimize human flow.

• By stacking two cars on top of each other, one for odd floors, one for even.

• Elevators can carry twice as many people without adding to their overall footprint.

• As a result, they offer a reduction in the amount of unrentable core space dedicated to systems like utilities and elevators.

• COMPASS DESTINATION ENTRY

• In 2005 the Otis company introduced Compass, a new interface that allows users to select the floor they need before they step onto the elevator. Then the system evaluates all the current requests, selects the best elevator for that passenger, and directs her to it.

• REGENERATIVE DRIVE

• Also in 2005, Otis introduced regenerative drive on its elevators

• As the elevator descends, Otis' ReGen system uses that kinetic energy to generate electrical energy, releasing it into the building's grid.