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Every Mechanism

Home How an Elevator Works

From a button press to a level stop

How an elevator works

Press a button and a car arrives, stops level and opens its doors. Here is everything behind the walls that makes it happen.

Call the lift
The top of a lift shaft cut open beside the building: in the machine room on the roof, the blue machine with its grooved sheave and the red governor; below it the stainless car in its yellow frame, stopped at the top floor with its doors open onto the lobby, its ropes running up to the sheave.
The lift in section: the car has stopped level at the top floor, under the machine that lifts it.
1:1
roping: the counterweight moves as far as the car
1,550kg
counterweight: the car plus about half its load
1.6m/s
rated speed
115%
of that, and the governor grips its rope

Video

How an Elevator Works - From the Button to Your Floor

Watch on YouTube

3D model · cut open · 360°

Call it, ride it, take it apart

The whole lift, cut open. Press a floor, drag to turn, scroll to zoom, click any part.

Try itPress a floor below, or click a call button on a landing. The controller sends the car there.
Loading the 3D model…
Send the car to

Meet the parts

Eighteen parts, one lift

The lift taken out of its building. Tap a part or pick a name below.

The parts of a traction lift standing on the ground: a landing door with its call buttons, the stainless car in its yellow frame between two lengths of guide rail, the yellow counterweight frame full of iron weights, the controller cabinet with its circuit board and the drive cabinet at the back; the blue machine with its grooved sheave and brake, the deflector sheave, the red governor with its tension sheave and the two yellow oil buffers in front.

Hover or tap the picture. Blue rings mark every part.

Parts diagram

From the machine room to the pit

Side view in three slices: machine room, car, pit. The numbers follow a call through the lift.

A side view of the lift in three slices. Top: the machine room with the controller, the blue motor with its brake and the grooved traction sheave, the deflector sheave and the red governor. Middle: the car at the third floor with its doors open onto the lobby, its door operator on top, the yellow counterweight passing behind it, the ropes, the steel tape and the guide rails. Bottom: the pit with the governor's tension sheave and the yellow oil buffers. Twenty numbered parts.

The floors in between are left out: the shaft is about 22 m from the pit floor to the machine room’s roof.

    How it works, step by step

    Twenty steps from the button to the stop

    The video’s steps. Press Show me in 3D to see each one in the model.

      The building in section with its lift shaft.
      Step 1 of 20

      You press, it comes

        Demo · why there is a counterweight

        Balance the car

        The counterweight balances the car, so the motor only moves the difference. Load the car and run a trip.

        • Blue: the motor is driving.
        • Green: the motor is braking the heavier side and feeding power back.
        –heavier side, by
        –steady pull and torque at the sheave
        –motor power at full speed
        –energy for the trip

        Demo · how the sheave grips

        Will the ropes slip?

        Only friction in the sheave’s grooves pulls the ropes. Change the load, grip and wrap and see when they slip.

        –pull on the car's side
        –pull on the counterweight's side
        –ratio · most the grooves hold
        –the ropes

        Demo · the controller's list

        Call the lift

        Press landing and car buttons in any order and watch the controller answer them.

        • Amber: a call the controller holds.
        • Green: where the car is, from the tape.
        –the car
        –calls waiting
        –average wait
        –distance travelled

        Demo · what if it runs away?

        Stop a runaway car

        At 110 % of the rated speed the governor cuts the power and drops the brake. At 115 % it grips its rope and the safety gear wedges the car to the rails.

        –car speed
        –governor
        –stopping, in g
        –from the switch to the stop

        More to know

        Kinds, history and care

        Six kinds of lift

        This oneGearless tractionMotor turns the sheave directly. Tall, fast buildings.
        Older or smallerGeared tractionA faster motor through a gearbox. Low and mid-rise.
        No machine roomMachine-room-lessA compact machine inside the shaft.
        A few floorsHydraulicAn oil-driven ram pushes the car up.
        Very tall buildingsDouble-deckTwo stacked cars serve two floors at once.
        Building sitesRack and pinionA toothed wheel climbs a toothed mast.

        From a safety catch to computers

        1. Otis shows his safety catch: the rope is cut and the platform holds.
        2. The first passenger safety lift, in New York.
        3. Siemens builds the first electric lift.
        4. Alexander Miles patents automatic doors.
        5. The first gearless traction lifts.
        6. The first lift without a machine room.
        7. The world’s fastest lift: 21 m/s.

        Riding safely, keeping it safe

        • Stuck? Stay calm. Press the alarm and wait for help; never force the doors.
        • Don’t block closing doors with a hand or a bag.
        • Respect the load plate. An overloaded car won’t start.
        • In a fire, take the stairs.

        Things worth knowing

        The motor moves only the differenceThe counterweight is the car plus about half its load.
        Going down can make powerThe motor works as a generator.
        Doors, drive, brakeEvery trip starts in that order, and stops in reverse.
        Locked unless the car is thereNo landing door opens without the car.
        Two safety stagesSwitch at 110 %, grip at 115 %.
        Oil buffers above 1 m/sThey slow a car evenly instead of bouncing it.
        Quick check

        Four questions