抄録
When the vertical element of ellipitical vibration is larger than 1.0G, works jump and the characteristics of transportation change considerably. However, a part of works don't jump and the characteristics don't change. This phenomenon allows us to separate jumping works from not jumping one. It has been understood the cause that a part of works don't jump in the condition to exceed the jumping limit is negative pressure on contact face. It has been understood that terminatory volume of negative pressure depends on length of gap. Moreover, the factor that the works jump is considered by observing the moment when the object jumps.
