In general there are different types of lifting machines and many do not require the use of special steels to withstand the loads to which they are subjected; the more sophisticated machines however, require special structural calculation know-how to ensure lifting capacity, safety and service life.
This type of more complex machinery can be divided as follows:
This type of equipment has evolved rapidly over the years with great improvements in terms of size, lightweight, capacity. Generally speaking all the performances for which they are designed have significantly improved.
This positive change is primarily due to the steels employed and to the creativity and calculation expertise of the designers, which have taken into account all the yield strength limit options to meet the various types of lifting needs.
Until the 80’s these machines were excessively heavy because they required considerable steel thickness and welding operations as cold forming was difficult or even impossible. Nowadays arms with different sections can be build, using cold bending processes and one single weld to close the arm; steels with different yields (700 MPa, 900 MPa, 960 MPa, 1100 MPa, 1300 MPa), or a combination of steels, can be used to obtain lighter machinery with increased capacity.
When a truck-mounted crane arm is fully extended and carries a load there is the so called “fishing rod effect”. When the load has been released, the tension is normalised and the very obvious curve caused by the load disappears so that the hydraulic extensions can be retracted, not just once but throughout the crane’s service life. In the past this was not possible as the structure of the cranes was archaic, stiff, heavy and not very versatile; in addition the arms were heavily welded with weld seams and areas affected by the heat, which created extensive weakness points.
Today’s press brakes can cold bend all the steel categories mentioned above and the shapes required by the designer for the different sections can be skilfully achieved thanks to the expertise of the workers. The entire lifting world has benefited from this evolution in the manufacture of heat treated steels; the machines to deform the steel have also followed this evolution and their characteristics have been adapted in relation to the steels to be processed.
This sector represents the core business of VENTURI ACCIAI srl. The company carries out all the operations necessary to build the parts of the lifting machines previously mentioned: adequate cutting, preparation of the edges for subsequent welding and cold bending using our wide range of presses of different sizes and capacity.
We do not only produce arms but also outriggers, frames, turrets and dozens other components are processed and supplied in kits packaged ready for delivery.