i was thinking about this the other day. theoretically, what would happen if a hydraulic elevator was proceding downward and got stuck or caught on the elevators frame(for whatever reason, say something sticking out of the car door from a passengers' belonging)... if the elevator became suddenly unstuck again, would this complicate the hydraulics or it's safety?

-- Jobocop (machecatz@hotmail.com), August 16, 2004

Answers

I the lift is a roped hydraulic then is will be fitted with a slack rope detection which will cut the electrical supply stopping the lift,if the lift continues to descend the safety gear would be engaged, or alternatively the lift will have a low pressure detection system which would stop the pump and close the valves retaining the oil in the ram. The latter system would be used on a direct acting

-- geoff judge (geoffjudge@bchtgroup.org), August 17, 2004.

so all hydraulic elevators come equipped with some sort of device to shut off the system if the door catches? or is this an optional system? are there any other kinds out there?

-- Jobocop (machecatz@hotmail.com), August 17, 2004.

No, they are not all equipped with these devices. As the previous answer states, roped hydraulics have some additional safety features. In a conventional type hydraulic it is the weight of the car along with gravity that lowers the car. If the car was to become hung up, it would stay in that postion until the obstruction is removed. Typically, no damage would be caused to the hydraulic system.

Remember that hydraulic elevators are regularly supported under the car when service work has to be performed. (Head packing replacement)

-- Robert (robert@elevatorconsultant.com), August 18, 2004.

One thing not mentioned is that all hydralic rams should be bolted to the strick plate so if a car does get hung up for somereason atleast the ram doesnt continue going down without the car. J

-- Jim (elevator555@hotmail.com), August 19, 2004.

the reason i ask is that while at work, the elevator door closed over top of my dolly... which ended up getting caught on the lip of the elevator frame surrounding the car. the dolly became unstuck, and the car continued on it's path... it made a loud noise but no one at work seemed to notice. i'm worried that as the weight of the car was being transferred to the lip of the frame, that it might have damaged the hydraulics, possibly bending the cylinder. can u guys get back to me on this, cuz i'm rather frightened... i've left a note for the inspector next time he comes in.

-- Jobocop (machecatz@hotmail.com), August 19, 2004.