Patent ID: 8511513

Claim:
A dispensing system, comprising: first and second chambers, each having an inlet port configured to allow flowable material to pass into said chamber and an outlet port configured to allow said flowable material to pass out of said chamber; a first displacement rod slidably disposed in said first chamber, said first displacement rod having a displacement volume that is smaller than a total volume of said first chamber; a second displacement rod slidably disposed in the second chamber and configured to operate in coordination with said first displacement rod, said second displacement rod having a displacement volume that is smaller than a total volume of said second chamber; said first displacement rod being configured to force a volume of said flowable material that is substantially equal to said first displacement volume through the outlet port of the first chamber when said first displacement rod penetrates into said first chamber; said second displacement rod being configured to force a volume of said flowable material substantially equal to said second displacement volume through said outlet port of the second chamber when said second displacement rod penetrates into said second chamber; and wherein said first and second displacement rods have geometries that are configured to maintain open space between the first displacement rod and walls of the first chamber and between the second displacement rod and walls of the second chamber, such that flowable material can flow between said displacement rods and said walls from a first end of said displacement rod to a second end of said displacement rod.