Pneumatic control system for a trolley dispatch network

Claim 1

A pneumatic control system for a trolley dispatch network having a plurality of sending stations coupled to a main rail, a plurality of receiving stations coupled to a plurality of rail spurs, a plurality of switches each associated with a spur and positionable in the main rail and moveable to a switched position for diverting a trolley carrier to the associated spur, comprising: manipulatable coding means carried by each trolley carrier and arranged to identify the receiving station to which the trolley carrier is destined; pneumatic detection means associated with each of the spurs for detecting the code elements on the trolley carrier; pneumatic logic circuitry associated with said detection means and energizable upon the simultaneous detection of the code elements identifying the destination of the trolley to the associated spur; and pneumatic means actuable by said pneumatic logic circuitry for operating the associated switch to guide the trolley carrier to the spur coupled to the receiving station to which it is destined, said coding means including a predetermined number of code pins, and a perforated board, said board having a plurality of apertures for receiving pins in selected apertures to form a code identifying the receiving station to which carrier is destined, said pneumatic detection means including a pluRality of proximity detecting elements, said elements being positioned to represent a receiving station associated therewith, each of said code pins including contact arm, and said pneumatic detection means include contact elements which are tripped by the contact arms as the trolley carrier passes by said detection means, said pneumatic means including a pneumatic valve and cylinder coupled to said switch, including means for pneumatically detecting the movement of a trolley onto a spur from the main rail and means for moving the trolley beyond said switch.