Article exchanging apparatus

In an article exchanging apparatus for removing a consumed article from a processing unit and replacing same with a fresh consumable article having base plate means for engagement with transporting apparatus capable of being moved substantially horizontally, lifter means secured at one end to said base plate means in suspended relationship thereto, and article gripping means secured to the opposite end of said lifter means for releasably engaging a fresh or consumed article, the improvement of an article level unit for insuring the proper replacement of a fresh article for a consumed article at the same level at which the consumed article was at the time of its removal, said article level unit comprising load switch means interposed between the base plate means and the lifter means to constitute the connection therebetween, said switch means being actuatable by the weight of the article and the associated parts to which it is connected, means for detecting the vertical displacement of the consumed article operatively associated with the lifter means and the article gripping means, pulse generator means operatively connected to said vertical displacement detecting means for generating a signal corresponding to the upward or downward movement of the article, article level measuring and indicating means operatively connected to said switch means and to said pulse generator means, said article level measuring and indicating means including an indicator unit operable to give a value corresponding to the level of the article whereby said article level measuring and indicating means will be actuated by said switch means upon the raising of a consumed article and which will receive a pulse generator signal to indicate the vertical displacement of the consumed article in terms of a fixed value on said indicator unit, said switch means will be closed upon release of the consumed article and will be reactuated upon engagement by said article gripping means of a fresh replacement article and will give on said indicator unit the vertical displacement of the fresh article in terms of a fixed value and the vertical height of the fresh article will thereafter be adjusted to give a zero value setting corresponding to the final reference value thereby placing the fresh article at a level coinciding with the level of the consumed article at the time it was withdrawn.