Detection of multiple document misfeeds in automatic feed machines

Multiple document misfeed occurs in an automatic feed machine when two or more documents are transported through the machine instead of one. The purpose of this project was to examine two types of systems (a cantilever beam and a rigid beam/spring system) as potential means of detecting these misfeeds.

To accomplish this, a model was developed for the document/detector impact assuming the document behaved as a spring/damper system affixed to a rigid, constant velocity beam. Given this model for the impact response, both designs were analyzed using dynamic considerations yielding a predicted response of the systems. These were verified experimentally.

It was found that the rigid beam/spring design was unacceptable (did not satisfy the given constraints), while the cantilever beam design provided an acceptable solution, the best of which is given below.

Beam thickness = 0.011 inches

Total beam length = 1.5 inches

Striking angle = 4 degrees

Preload = 0.27 pounds.