Slightly off-topic: US Elevators amd interlocks?

Since when are movies true to life?

How many cheesy action movies do you see a cable flapping around sparking? It would appear that they do not have circuit breakers or fuses in the movies neither!

I like all the cars that explode into flame when they go over a cliff!

On Wed, 15 Dec 2004 14:55:12 +0100 T.S. wrote:

| I have an off-topic question: do landing doors in US elevators have | interlocks? | | According to the European lift standard EN 81 all landing doors have to be | equipped with interlocks so that the doors could not be easily open when for | example there is no car behind them. You need a special tool to open them in | emergency. An interlock also has a contact to be put in a safety circuit.

I don't know about the rules, but every elevator I've been in has them.

The inside car gate, however, did not have any interlock on all the elevators I saw when I was in college. It was a common school prank to open them while the elevator was moving. And of course when that happens the elevator stops at the next landing. But the interlock is tied to the gate, and now the gate can't open the door. The gate hits the outside of the interlock in this condition and can't close, either. Stuck elevators were common.

What was funny is that the front desk people at the dorm had the special tool. Yet when security or fire department people came to rescue someone stuck in an elevator, they neither had such a tool, nor went to fetch it. I saw several of those incindents myself. I would join in because I knew the mechanism. I didn't have the tool. What I did was instructed the people inside which level to pull on the door to unlock it. It always worked and the security/fire people were always astonished that it was so simple after they spent several minutes trying to pry the doors open. Then what really got their goat was in the commotion, I would step inside the elevator myself and let the doors close (and they would lock). Now they thought I was stuck and sometimes even tried prying the door again. Sheesh. You'd think they would figure if I knew how to tell other people how to unlock it, that I could do so myself. Actually, I took a small wooden dowel in with me. That was long enough to reach the gate sensor. I would trip that and let the elevator move along thinking the gate was now closed, even though I had it propped wide open. Then I would stop between floors (just let off on the sensor switch) and let it close now that the door mechanism is not in the way. The security/fire people would have left a stuck elevator unoccupied and unusable. What I did was left an elevator back in normal usable condition (until the next time someone tried the same prank).

| Somehow, on american movies the doors can be so easily open. That makes me | curious if the rules are so different.

I don't think script writers have to follow the rules in their stories.

Same here in the UK, except forcing the internal doors normally results in instant halt of the car, whereever it is, and without any of the normal gradual breaking. Pushing the door closed again used to result in resumption of service after a delay in the ones I was familiar with.

daestrom

Now, now. That's easily explainable. Typically, anyone driving over a cliff would probably $#!+ their pants. This driver, however, having recently eaten a big batch of cabbage and kelbasa, and is, of course, smoking, lets one hellaciouos fart and . . . .

:-)

Now, now. That's easily explainable. Typically, anyone driving over a cliff would probably $#!+ their pants. This driver, however, having recently eaten a big batch of cabbage and kielbasa, and is, of course, smoking, lets one hellaciouos fart and . . . .

:-)

Thank you all for the answers.

That's what I thought: it's just another hollywood bull****. They don't seem to care about details, if details do not match their vision ;-)

The only exception (as far as I remember) was "Speed" with Keanu Reeves - film makers noticed, that a lift has safety gears ;-)

Regards,

-- Tom

Spam trap: "to_nie_ten_adres" -> "jakubwedrowycz"

|>

| | *BEFORE* they reach the bottom of the ravine!!! Yeah, that's one of my | favorites too.

It's still plausible in real life. If the vehicle has run through a metal guard rail or other hardened obstruction, but has the force to go over or punch through, the resultant damage and impact could rupture the gas tank while also creating sparks that can ignite the tank. Of course you'd probably see just some fire on the tail of the vehicle. It would not be the effect Hollywood wants.

On 15 Dec 2004 20:31:29 GMT Andrew Gabriel wrote: | In article , | snipped-for-privacy@ipal.net writes: |> On Wed, 15 Dec 2004 14:55:12 +0100 T.S. wrote: |> |>| I have an off-topic question: do landing doors in US elevators have |>| interlocks? |>| |>| According to the European lift standard EN 81 all landing doors have to be |>| equipped with interlocks so that the doors could not be easily open when for |>| example there is no car behind them. You need a special tool to open them in |>| emergency. An interlock also has a contact to be put in a safety circuit. |> |> I don't know about the rules, but every elevator I've been in has them. |> |> The inside car gate, however, did not have any interlock on all the |> elevators I saw when I was in college. It was a common school prank |> to open them while the elevator was moving. And of course when that |> happens the elevator stops at the next landing. But the interlock | | Same here in the UK, except forcing the internal doors normally | results in instant halt of the car, whereever it is, and without | any of the normal gradual breaking. Pushing the door closed again | used to result in resumption of service after a delay in the ones | I was familiar with.

Yes, forcing the gate (the term used for the inside door, at least in the USA) open would stop the elevators. But the stop is not instantaneous. It will still travel a couple feet. I know because I have ridden them with the gate wide open and manually (insulated) contacting the gate trip switch to simulate the gate being closed ... and then let it open. The elevator will stop when the pranks were done, too. Sometimes it would stop between floors where the gates could close again and the elevator resumes. That's might well have been most of the cases. But in at least some of the cases, this happened right at a floor, either as it was being passed by, or while it was slowing to a stop.

On the Otis elevators I've seen, there was a blade about 10 inches long on the gate that slid between two rollers on the inside of the door. At a floor landing, it stops between the rollers. As the gate opens, the outer roller is pushed by the blade bar. It swivels up and pulls a wire that releases a spring loaded interlock on the door at the top and bottom.

If it stopped at the floor with the gate already open, then the blade bar is now positioned "outside" of the roller and cannot push it outward to to release the interlock. When the gate attempts to close, it hits the outside of that roller, which prevents the gate from closing all the way. The gate stopped at that position does not close the trip switch, and the control system will not put the elevator in motion. The gate closure then times out and reopens, but to no avail since nothing can get the mechanics back into the correct position without moving the elevator car up or down by at least several inches.