Programmable multiport switch

A switch comprising:

• a valve housing including a plurality of essentially parallel passageways, each such passageway having at least one port;
• a valve stem positioned to reciprocate longitudinally in each of the passageways to control the corresponding port, each such stem including a head and having a first position and a second position;
• biasing means for biasing each stem toward its first position;
• and
• a movable member positionable adjacent to a housing surface and movable in a direction essentially perpendicular to the direction of reciprocation of the stems, said movable member including a plurality of essentially flat surface portions and a plurality of cavities, the positioning of said surface portions and said cavities being programmed to bring one of said portions or one of said cavities into alignment with each valve stem head when the movable member is in any one of a plurality of predetermined positions;
• wherein, when any one of said surface portions is moved into alignment with any one of the heads, said portion bears against said head and moves the corresponding stem inwardly against the force of the biasing means into its second position;
• and when any one of said cavities is moved into alignment with any one of the heads, the corresponding stem is urged into its first position by the biasing means;
• and
• wherein, when any one of the stems is in its first position, an outer portion of its head extends into one of the cavities and an inner portion of its head is seated against an edge portion of said cavity.