Halfbakery Multiple Elevator Cars Per Shaft

Halfbakery Multiple Elevator Cars Per Shaft

Multiple Elevator Cars Per Shaft

Synopsis: See Description underneath Title.


Imagine an ordinary elevator shaft, which has a powerful electric winch at the top, and a cable supporting the cab. Note that this is not the whole story; there is a second cable coming from the winch, that supports a counterweight. This counterweight is generally shaped like a thick rectangle, and slides up/down along one wall of the shaft (always missing the cab, of course); it also has somewhat more mass than the cab, such that when the cab holds an average number of people, THEN the masses balance. When either is lifted in the shaft, the other is let down. The electric winch has a comparatively easy time doing this, and only needs to be powerful enough to handle the maximum people-associated difference in mass between elevator cab and counterweight.

For this Idea, we require winches that are rather more powerful than normal. Also, each winch motor must actually be a motor/generator, as will be explained shortly. Finally, certain elevator cables also need to be quite a bit stronger than normal. Then all we need is some fancy computer software and control circuitry, along with standard elevator-safety equipment (if a cable breaks, certain levers that depend on cable tension are released, causing a cab to physically latch onto the walls of the shaft).

Let’s consider a 40-floor building, and a single elevator shaft with five cabs in it. (This is not to imply that the building only has one elevator shaft; it is that I only need to describe one. ) The spacing between floors is such that a simple stack of the five cabs can simultaneously serve any five consecutive floors, depending on where the stack is located in the shaft. As you will see, there is reason to fill this building with such a variety of destinations that the people living and/or working in the building will not need to frequently leave the building.

Inside the shaft, starting at the top, we have two Primary Winches. Each controls one cable, one leading to the topmost cab in the shaft, and the other leading to the topmost counterweight in the shaft. As mentioned, the motors for these winches have to be extremely powerful, and they also need to be motor/generators. Finally, cables need to be extra thick and strong, and long enough to let the topmost cab reach down to the fifth floor (not counting any basement floors).

Halfbakery Multiple Elevator Cars Per Shaft

Next we have the topmost elevator cab and counterweight in the shaft. Embedded in the floor of the cab is another winch, with a very powerful motor/generator. Also, attached to the lower part of the counterweight is also another winch, again with a very powerful motor/generator. Only one cable leads from each of these two winches; they do not need to be quite as strong as the uppermost cable, but they are as long, able to reach across 35 floors of this building.

Next, lower down in the shaft, we have another elevator cab and another counterweight, supported by those just-described cables. These are also equipped with winches and motor/generators, although they do not need to be quite as powerful as the uppermost pair. Also, again the cables that descend from here don’t need to be quite as strong as before — but still 35 floors long.

Repeat for three more elevator cabs and counterweights, except of course the bottommost ones do not need any attached winches, cables, etc. And each motor/generator and cable that IS included can again be somewhat less powerful/strung than the one above it.

OK, now to describe this system in action!

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