Resonance-induced failure of entrapment: Application to industrial parts feeding

Parts feeders are devices used in automated assembly lines to present compo nent parts to the assembly machinery in a consistent and predetermined orie ntation. The process of converting a randomly oriented set of parts (as obt ained from a vendor) into an ordered array is called parts feeding. There a re many different types of feeders and feeding techniques used in the indus try. This paper deals with a particular feeding process referred to here as vibratory entrapment. It describes a particular cause of failure of vibrat ory entrapment, namely, resonance. Failure due to resonance was first obser ved in high-speed video images of the entrapment phenomenon. This paper pro vides a description of the mechanics of failure of entrapment due to resona nce. The mechanics is introduced with the simple example of a ping-pong bal l in a cup and extended to real parts in a parts feeder Conditions for reso nance are derived and experimentally verified for a simple part shape and v ibration pattern.