3 replies to this topic

[Martin]

hi,
i was looking on skillifts.org for some information about forces in gondola. have you seen some diagram, picture showing how does it look like?(rope, hanger, vehicle). i've just started my M.A thesis about projecting the gondola transport at my University and i'd like to get some basic information, cause the sources i've seen so far are rather amateur :P


i'll be gratefull



greetings
Martin

This post has been edited by Martin: 05 January 2007 - 07:41 AM

[Lift Dinosaur]

Hello Martin,
What do you mean by "forces"? I do not think that is the correct term in English.

Dino

[Martin]

I used physical word for describing that ; i mean for example: centripetal force, moment of inertia, air resistance.
Some information which can explain physical strenghts, like on enclosed picture.
 9.JPG (9.89K)
Number of downloads: 47




i hope that now You will get it. I haven't wrote in English for a long time ;)

[Kelly]

Hi Martin
I have added other indicator numbers for missing force.
I will try to use universal numbers for force.
To make it simpler lets assume load #8 = 1000.
Each force will have a simple explanation.

#1 = 1000 – Straight reaction while carrier is on haulrope.
#2 = 1000 – Straight reaction while carrier is in terminal
#3 = +6000 – This is a dual purpose roller, one function is to guide and align the grip before detaching, and the other is to provide a resisting force that force #5 imparts as the grip opens or closes. see #7
#4 = - 6000 – See above.
#5 = 0 to 6000 – This is a small centripetal force but for the most part can be call a straight reaction to the grip spring. (Your diagram is good but is missing the flat plate above this roller that activates the arm).
This explanation was provided by Ryan B of skilifts.org
#6 = 500 – Short duration down force but does transfer horizontal motion to accelerate and decelerate the carrier while the grip is detached.
#7 = 1000 x safety factor of 6 = 6000 - This force is applied while the grip is attached to the cable – Not given in your diagram, this is the grip force on the cable. The energy is supplied by springs of many different types. Force #5 has to overcome grip force #7 each time the carrier enters and leaves the terminal.
Other notes:
Force #2 also has a short duration reaction while force #5 is active.
Force #2 and #3 provide short term resisting to #6 while the carrier accelerates.
Force #7 resists the loads that the grip will have a reaction to – such as acceleration and maximum deceleration in extreme angles on the cable plus a factor of safety.
It should also be mentioned that the grip design has a safety factor of at least X10.
Gravity (carrier load) is no longer used for grip force.
Common springs used for grip force are wound, torsion bar, and cupped washer.
Air resistance is a very small component of grip force so it is usually ignored – however air resistance is very much a part of cabin design and tower sheave loading.
Ryan B

Attached File(s)

•  martin_jpeg_for_web.jpg (56.42K)
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