Levitators A new concept for elevators in tall buildings © 2007, Rajaram Pejaver Patent Pending Press the key to advance Press the key to replay a slide

Levitators: Overview The opportunity Todays technology The solution Future extensions Key innovations Main issues & obstacles Project timeline Feedback

What does it do? 1. Improves elevator service in existing buildings without adding banks of elevators 2. Reduces floor space needed by elevators in new tall skyscrapers 3. Allows for unique building shapes in new architecture

Product application: Existing buildings Examples of target buildings – Office buildings – Hotels – High rise Apartments Typical height of building is 10–20 stories Its not possible to add new elevator shafts to building Levitators will increase passenger capacity threefold and reduce wait times.

Product application: New skyscrapers More and more tall buildings are being built – China has 5 of the 10 tallest buildings – Malaysia and Taipei have one each in top 10 – Canada is building new residential skyscrapers More than 30% of floor space in skyscrapers is consumed by elevators! Taipei 101 in Hong Kong has more than 57 elevator shafts!! Levitators will reduce the number of elevator shafts and increase its utilization Taipei 101

Todays technology Limited to one elevator car per shaft Based on counterweights

A solution: multiple cars per shaft! The Thyssen Twin is an example of such a system. But cars are limited to the upper or lower portion of a shaft.

But, what if the lower car needs to go all the way to the top? Two elevator cabs, one moving down and the other moving up, share the left shaft. Lower cab shifts to the adjoining shaft and carries on.

The system in operation Rule: # of cars going up equals # of cars going down Car 1 needs to go all the way down Car 6 needs to go all the way up Cars 1 & 5 are moving down Cars 6 & 7 are moving up Cars 1 & 2 are moving down Cars 6 & 4 are moving up Cars 1 & 2 are moving down Cars 6 & 5 are moving up Cars 1 & 2 are moving down Cars 6 & 5 are moving up Car 7 is moving left Car 3 is moving down Car 7 is moving up Press Backspace (or PageUp) to play this again And see the Java based interactive simulator.

How does it all work? First, the Drive Assembly Endless loop around two pulleys One side constantly moves up at a steady speed and the other side moves down A third track (middle) is stationary and acts as the guide rail for cars Cars clamp on to the track moving in the desired direction: up, down or stationary. Floor 1 Floor 2 Floor 19 Floor 20

Positioning of Drive Assemblies in each shaft: Front and Top views Shaft Drive Assembly Clamp There are 4 Drive Assemblies per shaft. Car is clamped on to upward moving track. Yellow dots indicate location of clamp. There are 8 clamp points for each car. Clamp Car Top View of car in a shaft Door

What else? Next, the Clamp Runner Clamp runners slide horizontally. They are installed in pairs at the top and bottom of cars. A clamp is mounted at each end. The upper runner is shown in operation. The lower runner operates independently. Clamp runners can slide right and engage or slide left and engage and return to the center position.

Clamp operation Caliper Runner Upward moving Drive Track Fluid Car at rest Car moving up Clamps are mounted at the ends of each runner. Car transitions from being stationary to moving up when the clamp is engaged. Clamp action is controlled for smooth starts. Pad Piston Press Backspace to play this again

Car at rest Shaft Car Drive Assembly Clamp Car is clamped on to the stationary tracks. Note yellow dots on upper runner clamping on to the center tracks. The stationary tracks act as guide rails to stabilize the car while it is in motion. Note: Not drawn to scale Stopped

Car moving downwards Shaft Car Drive Assembly Clamp Car is clamped on to downward moving track and is moving down. The upper runner is unused. Note yellow dots on downward moving tracks.

Transition: Start of upward motion 2. Lower Runner moves left over upward moving track 3. Lower runner clamps on to upward moving track 4. Upper runner releases stationary track 5. Car starts to move upwards Stopped 1. Car is stopped. Upper runner is clamped to the stationary tracks. Lower runner is not being used.

Transition: Coming to a halt 2. Upper runner clamps on to stationary tracks 3. Lower runner releases upward moving track 4. Car comes to a halt Stopped 1. Car is initially moving up. Lower runner is clamped to upward moving tracks. Upper runner is over the stationary tracks.

Transition: Switching Shafts 1. Clamp extends to adjoining shaft 2. Clamp locks up 3. Cab shifts 4. Clamp unlocks 5. Clamp retracts

Counterbalancing Cars Figure 2a – 2 cars balance each other on same drive Figure 2b – 2 cars balance each other on different drives – Shafts are mechanically linked Figure 2c – 4 cars balance each other on different drives

Multiple Drive Zones Problem: Drive assembly limitation – A single span of drive assembly is not suitable for tall buildings. Solution: Stacked drive segments – Allows for shorter drive segments – Optional: express & local speeds Details: Car switches drives – Both segments serve the same shaft – Segments are mechanically linked – No horizontal car motion Transition Zone

Slanted & Curved shafts

Future extensions Tilting cars during horizontal acceleration – Reduces passenger discomfort Moving horizontally between elevator banks Personal sized elevator cars – Faster transit with fewer stops Splicing cars together to form a larger car Express drive zones

Key Innovations Elevator system without counterweights Drive assembly for elevators Clamp assembly and clutch mechanism Use of extension arm in elevators to facilitate arbitrary transfer between adjacent shafts Statistical counterweight balancing algorithm Control system for collision avoidance and car trajectory Operation in slated & curved shafts Multiple drive zones and express zones

Main issues & obstacles Need to rework the US Elevator Code – Shared by Canada, and now China – Europe, Mid East & India may be easier Build a scaled prototype – Seeing is believing ! Design production model, while maintaining – current safety margins – operating efficiencies – passenger comfort

Project Timeline TaskStart DateEnd Date Patent searchJan 07July 07 Patent applicationJuly 07July 09 Engineering designOct 07Dec 08 Find venture funding July 08July 09 Assemble project team Jan 09July 09 Develop scaled prototype July 09Jan 11 Product development Jan 11…

Thank You !! What do you really think of all this? Send feedback to