ApplicationNo. 05/571317 filed on 04/24/1975
US Classes:417/413.1, Diaphragm type417/470Biasing means effects induction stroke of abutment driven, vacuum producing pumping member
ExaminersPrimary: Freeh, William L.
Assistant: LaPointe, G. P.
Attorney, Agent or Firm
International ClassesG01F 3/02 (20060101)
F04B 9/02 (20060101)
F04B 43/09 (20060101)
F04B 49/06 (20060101)
F04B 43/00 (20060101)
F04B 43/08 (20060101)
F04B 13/00 (20060101)
G01F 3/20 (20060101)
AbstractA metering pump for determining the quantity of a fluid flowing at an externally-determined rate, e.g., for measuring the volume of a gas, such as air, flowing through a flow-restrictive element, such as a filter, has a variable-volume chamber (e.g., a bellows) including a movable wall which is urged in one direction (e.g., toward expansion if an inspirator) by resilient means and is driven in the opposite direction by mechanical means, such as a reciprocable lever arm which engages the wall but leaves it during a part of its movement, said means having electrical contacts in a circuit which powers an electrical motor driving the mechanical means, the contacts being open when the mechanical means leaves the wall, permitting the wall to move at a rate determined by the fluid flow rate. Counting means, such as a counter, are coupled to the electric motor or circuit for counting the movements of the wall.