Some Other Types of Elevators
There are many other types of elevators in use today. Wheelchair lifts operate mainly from screw drives. Just envision a big screw and the car is attached to the nut on the screw. As the motor turns the screw it raises or lowers the car. Most are unsophisticated and only stop at a top or bottom limit. These are defined as LULA lifts (Limited Use Limited Access). They do have safety devices installed if, for instance, the gate is not closed the unit will not run. The gate locks between floors to prevent falling out or getting hooked on something during movement. Most have a safety switch on the bottom to stop the unit if it’s descending onto something in the pit to avoid crushing it. Other wheelchair lifts are stair climbing type devices. They ride along a rail mounted parallel to the stairway and accomplish movement by a set of cables. This type is usually complex. They will fold up against the wall after use to avoid taking up space. When activated they drop down to allow the rider to roll onto them, then a safety bar positions itself across the entrance to prevent the rider from rolling out while moving.
A really cool device that we don’t see much of here in the US is the funicular. I like to think of it as a cross between a streetcar and an elevator. Funiculars are used in urban areas where there are steep hills. The car is pulled up and let down by cables just like an elevator but it rides on rails just like a streetcar. Of course conventional elevators have rails too but those are used to steady the car during the vertical movement process.
There are also dumbwaiters, way too small for people to ride in. They can be hydraulic or traction and most have doors that open horizontally at the middle. Meaning the top half goes up and the bottom half goes down. Dumbwaiters are not designed for passengers all controls are at the hall stations. The way to operate them is to load them, close the door then press the destination button.
A similar device is a material lift. The “car” usually consists of a cage. They are mostly hydraulic/chain driven like the portable hoists that mechanics use in garages now. Material lifts like dumbwaiters are not built for passenger use therefore they have no controls inside the cage and the destination is determined by an operator at a hall station.
Construction sites use rack and pinion type elevators that are set up for temporary use. They are designed to carry passengers and materials to upper floors on construction projects. To understand their operation, just visualize a gear climbing a toothed rail. The motor travels with the car. These are very heavy duty and get tons of abuse on sites. The passenger/freight compartment is just a cage and for those who are afraid of heights can provide a load of thrills.
There are other types of elevators but for now these are the ones you’re most likely to see.
My next post will be on the hardest working system in any elevator….the doors.
Please let me know what you think of this blog along with any questions that you may have or any suggestions for subjects that you think everyone would like to see information on.
Remember that’s elevatorernie@hotmail.com
Regards,
Ernie
“Sometimes I wonder whether the world is being run by smart people who are putting us on, or by imbeciles who really mean it” -----Mark Twain
