The bed of an apron converyer designed for a load of large heavy fragments such as copper ore is subjected to heavy dynamic stresses at the loading point. It is therefore very important to allow for dynamic action in designing the plates of the bed. The large fragments of ore in failing cause heavy stresses in these plates. It is difficult to calculate the dynamic forces involved, because of the difficulty of determining the mass of the bodies participating in the collision. Accounting for the dynamic actions of the bed is especially difficult in designing new types of conveyers because preliminary calculations must be performed to select the initial structural characteristics of the bed.The development of methods of design calculations for machines and their components for percussive loads is a complex problem and is far from completely solved at present: it demands much theoretical and experimental work. For this reason we can only approximately estimate the shock loads on the conveyer bed plates. For this purpose we make the following assumptions. 1) The impact of the load on the plate is inelastic; after the impact the Ioad coalesces with the plate at the point of collision, and oscillates together with it.2) The rigidity of the masses participating in the impact and the local deformations of the colliding surfaces are allowed for by a coefficient which must be found experimentally.Let us consider the impact of a load P on a load P0 with rigidity C. At the moment of impact the velocity of load P iswhere H is the height from which P falls.After impact, the common velocity is found from the law of conservation of momentum, which gives

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