JACKS

Jack is a useful tools which provide to lift heavy burden up or change position of motionless substances by appling pressure. Jacks which have little capacity are used in machine tools and cars, jacks which hane big capacity are used in heavy machines and lifting the other burdens.

Jacks can be classified in two parts as mechanical jacks and hydraulic jacks. Moreover mechanical jacks have some various sub-groups such as screw jack, toothed rock jack etc. Hydraulic jacks have some various as mechanical jacks. For example bottle type hydraulic jacks, horizontal cars hydraulic jacks etc.

Screw jacks are formed by big and sequare or crooked chamfered steel screw. The screw usually screw into the nut that can turn freely at tip of the pipe. Ifthe nut is turned by simple or nailed handle the screw will go out from inside of thepipe. As a result of this, screw and the tip of the pipe will become distant from each other. The tips usually holds with lining onto the surfaces. So the apperture which is between the surfaces will increase. There is no need another system to stabilized irreversible system, because the step of screw is too small. The nut is constant in other screw jack types and so the screw is turned. Some of these are telescopic becausethe screws can go into each others. As a result higher lifting height can be provided based on tools own height. Screw jacks are used especially to lift burden up support the walls temporarly.

Toothed rock jacks are formed by toothed rock that are activated by the gearing. The fuselage of jack can be wooden or metal. On the top part of the toothed rocks, there is a couple of hook, and on the under partof the toothed rock founded a foot that can be put under the burden that is hanging on a few meters from the ground. There are two types of tuuthed rock jacks. One of is that fuselage of jack is constant and it’s toothed rocks are rising, the other type is that the fuselage of jacks are rising. Toothed rock is on the ground at the jacks that their fuselage are rising and the fuselage carries the burden.

Hydraulic jacks are made by a little diameter cylinder and a bid diameter cylinder. The burden on the big diameter cylinder can be lifted by appling afew pressure on the the little diameter cylinder. If the burden that is lifed up, wants to get down, liquid in the big diameter cylinder sends into water tank that is connected the big diameter cylinder by opening a valve. Hydraulic jacks can have huge capacity but increasing the capacity of jacks make the transportation harder.