History: Elevators

The old ones all used, at best, "relay logic" along with massive carbon and copper tipped contactors for load switching.

Google on "relay logic" and/or "ladder diagram".

They could do quite sophisticated control systems. In fact about 20 years ago a friend picked up (just for the scrap value) an early automatic lathe. It was based simply on about 80 relays, preset stops set by microswitches, and a programming patch panel. He could set it to run and walk away from it. The only manual intervention needed was to periodically feed new bar in from the end. He made money off it, doing contract turning jobs with a quick turnaround.

More than likely just relay logic. "Signal Control" introduced by Otis in '26 was all or most of it. The much earlier "Ward-Leonard" system (late 1800s) for speed control. I suspect that for quite a while the attendants were still there and pushed the buttons, kept an eye on things, and helped people find their correct floor. You'll still find attendants like that in many Asian countries, even though the elevators are fully automatic.

Best regards, Spehro Pefhany

Rent and watch the movie "Hotel" (1967) , where the elevator circuits play a major plot role.

(Partly kidding, you only see the elevator relays sparking for a few seconds, but they are important to the plot .... :)

Fine movie anyway.

You'll still find

IIRC In the old St. Paul, MN City Hall, a tall but poorly designed building, the elevators are manual, and they have a guy with castanets, an "elevator dispatcher", who makes sure the elevators are efficiently loaded. Weird to have the elevator operator wait until he gets "clicked off".

Relays and limit switches on the floors. We had one open cage one at the hospital I worked at when I was a kid. I served as the service elevator for taking food and supplies up to the floors.

Looked like the one we had, an old Otis - made less then a mile from the hospital, had a pair of switches per floor and would kick in a contactor to slow the elevator as it approached the stop. Once adjusted the setting would last for a long time.

Big noisy, cast iron housing, brush type motor, with the odor of ozone and machine oil about it. Large sheaves heavy cables and counter weights - all visible from the cage. The elevator would bounce for a bit after it stopped, you knew you were hanging on the end of a cable!

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In article , default wrote:

I use elevators all the time. I also use elevator logic to use those elevators. On one set in paticular, you need to know how to do some things to speed up your process. I see problems in the logic of that elevator. The elevator is old, but I'm sure its been updated with a computer, but the program could use a little help. For example; you hit the down button and then see one going up to 12. I'm on 11, the cafeteria, a high traffic floor. Up comes another elevator to 11, and opening, while the elevator on 12 is seen going down, not stopping on 11. The 11th floor should have some priority, and that down going elevator should stop on 11 in case there are too many waiting to go down. The other funny thing, many of us users learn. Your waiting on 11 to go down. An elevator opens showing going up. All of us that know, will get on that elevator, while sometimes 20 people are waiting to go down. Sometimes, that elevator we are on will not go up, but take us down neatly on an unpacked elevator. Knowing about the first problem, also tell us to get on the up elevator, and most of the time when it gets to 12, it goes and skips all those waiting people waiting on 11, if another elevator had come up to 11, and we go straight down on an empty elvator.. There are probably some new standard programs for elevators, but you really have to know the traffic patterns and time of day. You can also cheat and press the up elevator instead of down. The other funny thing about elevators is listening to people explaining all their actions, why they are doing what they are doing, like why they are going down on an up elevator, and of course most will act in a horid manner about doing that.

greg

The Ca-D-Zan mansion at the Ringling museum in Sarasota Fla has a controller on the elevator exactly like the one in "Hotel". They restored it to like new condition, with the help of Otis. The contacts on the relays are about 1.5" (38mm) across. It is really a very simple setup with 3 of those relays but this is manually operated.

While the history of elevators has a bunch of ups and downs, early controllers consisted of stepping relays and latching relays.

Ward Leonard is a speed control system for motors - not really just for elevators. If you see a good one it's a magical thing.

Yo, you lazy jackass. WTF are you, asking us doing your googling for you? Get out your checkbook to pay for our time, cheapskate.

BTW your amazing arrogant ignorance is disgusting.