Air valving mechanism, in combination with a double diaphragm pump subassembly

An air valving mechanism, in combination with a double diaphragm pump subassembly, comprising:

• a pair of plates having confronting cavity recesses formed therein, fastened together, to define a chamber therebetween, wherein said plates have parts, and rod-accommodating apertures formed therein;
• a rod slidably disposed in said apertures and having ends thereof extended outwardly from said plates;
• a cylinder having a longitudinal axis set within said chamber;
• a piston having a first axial bore formed therein, slidable within said cylinder, wherein said piston further has second and third bores, transverse to said axis, formed therein;
• first means, slidably disposed in one of said second and third bores, for (a) effecting fluid communication therethrough with said ports, and (b) sealingly engaging said plates and closing off such fluid communication with said ports;
• second means, slidably disposed in the other of said second and third bores, for effecting fluid communication of said first bore with said chamber;
• and
• means coupled to said cylinder for admitting motive air thereinto for (a) communication of such admitted air with said bores, and (b) slidably translating said piston in said cylinder and said first and second means in said bores.