Design and Structural Analysis of Automatic Reverse Locking Rack Mechanism for Car Jack

A screw jack is a type of jack which functions by the turning of a lead screw. It is commonly used to lift heavy load to a certain height. A good example is the car-jacks. In the case of a screw jack, due to the wear of trunnion’s thread it may cause the slippage of the lead screw and leads to the sudden fall of the vehicle which is been lifted by the screw jack. The statement of the problem has led to the motivation of designing the automatic reverse locking rack mechanism for car jack.The automatic reverse locking rack mechanism is a proposed system and method for preventing a vehicle from sudden fall when jack fails to support the vehicle for certain period of time. The work presented here reveals the construction and design of the screw jack safety system. The design is made to be compact for the ease of use. The best suitable material for the components were taken into account which are to be analyzed by finite element analysis method. Along with the results that obtained can give the conclusion about the stress, strain and maximum load carrying capacity with minimum deformation.