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In order to study the influence parameters for the wiper-windscreen friction, a test system was built, using an assembly of a car plane auto rear window glass, with the electrical motor, the wiper mechanism and also a wiper with a modified arm (by inserting a transducer to measure the friction force, based on tensometric strain gauges). Also on the wiper arm, on the opposite side of the arm/blade connection (located approximatelly at the middle of the blade length) a loading system was mounted. Different loading forces can be applied to the blade contact by gravity by simple changing the mass placed on this system. A large number of experiments were performed for different combinations of the values for the blade oscillating period and for the normal force in dry and wetted conditions for the blade-windscreen contact. The obtained results, reveal a direct correlation of the friction force with the load mass and with the relative speed in the contact (blade moving period). A higher friction occurs for the dry contact. This force has a higher increasing tendency for this contact than for the wetted contact when a stabilisation tendency of the friction force occurs.

3D modeling of the lifting platform was done in Catia V5R20 software. This soft was chosen as it gives an integrated solution, besides facilities related to modelling with solids which are common to all representative applications this also offers modules intended for stylists this way allowing extension of computer use also on previous stages of constructive engineering. The truck undercarriage is of LT28 type from Volkswagen producer. For 3D modelling, a leaflet from producing company was used. To represent the assembly of lifting platform firstly we realized a 3D model of the vehicle, and thereafter we realized the model of the nacelle type system and the manner of fixing on undercarriage. The finite elements study of the lifting platform was done by using Autodesk Inventor and for starting we determined the initial conditions type of network and material used. The main boom structure is calculated to stand for all stresses the platform is subject to. The structure is so designed that it can be fixed on the vehicle undercarriage frame. As a result of study, its maximum allowable stresses, travels and safety factor can be noticed. The first finite elements study was done on joint area between lifting platform boom and machine undercarriage, initial conditions were set within the study as follows: material mechanical properties type of performed study, force loading. Further to static study, data related to stresses, deformations and safety factor resulted. Maximum allowable stress in the boom of lifting platform has very small values wherefrom results that this stands a force applied on the other end.