Metered quantity dispenser guns and mixer combination

Claim 1

A gun for ejecting a metered quantity of material comprising: a first housing having a diametrically relatively large cylinder defining an actuating chamber; a second housing having a diametrically relatively small cylinder defining a displacement chamber; each said housing having an end adjacent the other said housing and an opposite outer end; a nipple interconnecting said housings at their adjacent ends with their said cylinders in axial alignment; said nipple having an internal bore axially aligned with said cylinders; a floating piston in said housings and nipple having a plunger portion at one end in said displacement chamber, an enlarged head on the other end in said actuating chamber and an intermediate portion in said bore; a first seal in said nipple at said displacement chamber and a second seal in said nipple at said actuating chamber sealing against said intermediate portion of said piston; a head seal on said piston head sealing against said cylinder of said first housing defining said actuating chamber; said piston head having a shoulder surrounding saiD intermediate portion of said piston with said shoulder facing toward said nipple and said second seal; said piston head having a top surface facing said outer end of said first housing; said piston head and said head seal dividing said actuating chamber into a retract portion facing said shoulder on said piston and an advance portion facing said top surface of said piston head; said first housing having a first channel leading to said retract portion of said actuating chamber for introducing air pressure bearing against said piston head shoulder; said first housing having a second channel leading to said advance portion of said actuating chamber for introducing air pressure bearing against piston head top; said second housing having an inlet port for admitting material to said displacement chamber and an exit port for emitting material from said displacement chamber; said second housing having means for connecting a first one-way check valve to said inlet port for passing material into said displacement chamber and preventing material flow therefrom and having means for connecting a second one-way check valve to said outlet port for passing material out of said displacement chamber and preventing material flow thereinto; said first housing having means for connecting said channels to valve means for selectively introducing air pressure into said retract and advanced portions of said actuating chamber at said shoulder and head top surface respectively to retract said plunger portion of said piston out of said displacement chamber to draw material into said displacement chamber and to advance said plunger portion of said piston into said displacement chamber to force material out of said displacement chamber; movement of said piston retracting said piston plunger portion out of said displacement chamber with said inlet port connected to a supply of material by a duct and through said a first oneway check valve as blocked by said second one-way valve at said exit port creating low pressure in said displacement chamber whereby atmospheric pressure or greater on the material forces material into said displacement chamber; and movement of said piston advancing said piston plunger portion into said displacement chamber with said exit port connected to an exit duct through said second one-way check valve as blocked by said first one-way check valve at said inlet port creating high pressure in said displacement chamber whereby atmospherical pressure on greater on the exit duct is overcome and the material in the displacement chamber is forced out of said exit port.