Hydraulic jacks suitable for lifting heavy objects, mechanical removal, bridge and ship repair, equipment, school adjustment, settlement, static piling, excavation works of non-use of hydraulic jacking machine and other operations.
Hydraulic jacks are typically used for shop work, rather than as an emergency jack to be carried with the vehicle. Use of jacks not designed for a specific vehicle requires more than the usual care in selecting ground conditions, the jacking point on the vehicle, and to ensure stability when the jack is extended. Hydraulic jacks are often used to lift elevators in low and medium rise buildings.
In a Floor Jack a horizontal piston pushes on the short end of a bellcrank, with the long arm providing the vertical motion to a lifting pad, kept horizontal with a horizontal linkage. Floor jacks usually include castors and wheels, allowing compensation for the arc taken by the lifting pad. This mechanism provide a low profile when collapsed, for easy maneuvering underneath the vehicle, while allowing considerable extension.
A simple frame, fabricated from steel, containing a bottle jack or simple hydraulic cylinder. Good for general-purpose work in the auto mechanic shop, machine shop, garage or basement shops, etc. Typically 1 to 30 tons of pressure, depending on size and expense. Classed with engine hoists and engine stands in many tool catalogs.
When the pressure on the press cylinder is released (the fluid returning to a reservoir), the force created in the press is reduced to a low value (which depends on the friction of the cylinder's seals. The main piston does not retract to its original position unless an additional mechanism is employed.