Metering pump with diaphragm
OwnerAlden A. Lofquist, Jr.inventor
Life of this patent
Estimating the term…
Abstract
There is disclosed a metering pump for metering and pumping small volumes of fluid. A continuous member with annular elements carries pumping fluid through a first passageway containing a diaphragm which defines a second passageway. Provision is made for changing the pressure of the pumping fluid being carried through the passageway. This causes the diaphragm to expand into the first passageway drawing fluid to be pumped into one end of the second passageway. The pumped fluid is then carried through the second passageway by movement of the continuous member with annular elements along the first passageway and delivered out of the other end of the second passageway.
Claims13
An apparatus for metering small volumes of fluid, comprising:
- a pump housing having a first fluid space and a second fluid space, and a wall separating said first fluid space from said second fluid space;
- an inlet opening for passing fluid into said first fluid space;
- an outlet opening for delivering fluid from said second fluid space;
- first pump means located in said wall for pumping fluid from said first fluid space to said second fluid space;
- and
- second pump means located in said wall for pumping fluid from said second fluid space to said first fluid space at a slower rate than said first pump means is pumping fluid from said first fluid space to said second fluid space so that said second fluid space is pressurized relative to said first fluid space, whereby fluid flows through said outlet opening out of said second fluid space and through said inlet opening into said first fluid space.
An apparatus for metering small volumes of fluid, comprising:
- a pump housing having a first fluid space and a second fluid space, and a wall separating said first fluid space from said second fluid space;
- an inlet opening for passing fluid into said first fluid space;
- an outlet opening for delivering fluid from said second fluid space;
- first pump means located in said wall for pumping fluid from said first fluid space to said second fluid space;
- second pump means located in said wall for pumping fluid from said second fluid space to said first fluid space at a slower rate then said first pump means is pumping fluid from said first fluid space to said second fluid space so that said second fluid space is pressurized relative to said first fluid space, whereby fluid flows through said outlet opening out of said second fluid space and through said inlet opening into said first fluid space;
- said first and second pump means comprising first and second pump blocks, respectively, said first pump block having a wall defining a first passageway connecting said first fluid space and said second fluid space and said second pump block having a wall defining a passageway with a smaller cross sectional area than the cross sectional area of said first passageway in said first pump block for connecting said second fluid space and said first fluid space;
- a continuous member having spaced-apart elements attached thereto, said continuous member and spaced-apart elements operable to be drawn through said first passageway in said first pump block to transfer fluid from said first fluid space to said second fluid space, and through said passageway in said second pump block to transfer fluid from said second fluid space to said first fluid space, said spaced-apart elements dimensioned to sealingly engage said walls of said passageways in said first and second pump blocks;
- and
- means for moving said continuous member and spaced-apart elements through the passageways in the first and second pump blocks.
In an apparatus for metering small volumes of fluids having wall means defining a first elongated passageway with open ends, pumping means in the first passageway including a plurality of spaced-apart members proportioned to sealingly engage the wall means defining the first passageway, means interconnecting the spaced-apart members, and means for moving the interconnecting means and its attached spaced-apart members through the first passageway, the improvement which comprises:
- an elongate, flexible, fluid impermeable membrane in the first passageway having marginal edges sealably attached to the wall means defining the first passageway to provide a second elongated passageway extending along at least a portion of the length of the first passageway;
- an inlet opening in the wall means defining the first passageway for connecting the second passageway with a source of fluid to be pumped;
- a first outlet opening in the wall means defining the first passageway to deliver pumped fluid from the second passageway;
- said inlet opening to said second passageway being positioned towards one end of the first passageway and, said first outlet opening from said second passageway being spaced from said inlet opening towards the other end of the first passageway;
- means for supplying the first passageway with pumping fluid;
- and
- means for reducing the pressure of the pumping fluid between the spaced-apart members adjacent said inlet opening to said second passageway and means for increasing the pressure of the pumping fluid between the spaced-apart members adjacent said first outlet opening from said second passageway, whereby pumped fluid is drawn into said inlet opening to said second passageway, carried along said second passageway, and forced out of said first outlet opening from said second passageway.
Dependencies are inferred from the claim text.