2006-06-18 04:47:09 · 5 answers · asked by caitlinrowlands@btinternet.com 1 in Science & Mathematics ➔ Engineering
It is a jack, like for a car, that is raised or lowered by spinning a knob.
2006-06-18 04:52:03 · answer #1 · answered by satanorsanta 3 · 0⤊ 0⤋
A screw jack is a threaded device designed to lift very heavy loads. It must have a driver (long lever?) that can turn the screw against the resistance but the slope of the threads must be gradual enough to prevent the load from rotating the screw. Thus, the lever must be used to raise and lower the load.
2006-06-18 12:05:15 · answer #2 · answered by Kes 7 · 0⤊ 0⤋
Screw jacks are the engineering version of a car jack or bottle jack.
instead of hydraulic fluid to cause the lift, it is worm gear.
Mechanics use them in garages to hold an engine in place when the car is up on ramps to take the strain off the connecting parts.
in a simple form look at a corkscrew.
Chris
2006-06-18 04:57:23 · answer #3 · answered by kipp[axkid 3 · 0⤊ 0⤋
In aerospace we call them jackscrews. And as kes already said, they are threaded rods, can be any length or diameter depending on the application. The load which requires lifting or moving has matching threaded socket which travels along the rod as the rod is turned. Boeing aircraft use jackscrews to raise and lower the wing trailing edge flaps.
2006-06-18 23:46:39 · answer #4 · answered by Munster 4 · 0⤊ 0⤋
check this page: http://www.nookindustries.com/jack/JackHome.cfm
2006-06-18 04:53:37 · answer #5 · answered by Linda 6 · 0⤊ 0⤋