Patent ID: 7758553

Claim:
A drop dispenser for dispensing a viscous liquid, comprising a substantially conical sleeve member having an upper end, a lower end, and an aperture centrally located at the apex of the upper end; wherein the lower end of the sleeve member is wider than the upper end of the sleeve member; wherein the aperture has an inner diameter and is circumscribed by a raised ridge having an outer diameter, an inner diameter the same as the inner diameter of the aperture, and a thickness, the aperture and raised ridge forming a nozzle at the upper end of the sleeve member; wherein the outer diameter of the raised ridge has a smaller diameter than an outer diameter of an upper surface of the upper end of the sleeve member; the thickness of the ridge extends parallel to a longitudinal axis of the drop dispenser; wherein the outer diameter of the raised ridge extends parallel to the inner diameter of the aperture along a portion of the thickness of the raised ridge; wherein an interior space of the substantially conical sleeve member forms a substantially conical chamber between the upper end and the lower end, wherein the nozzle is in liquid communication with the chamber by way of the aperture; and wherein the inner diameter of the aperture is from about 0.010 to about 0.060 inches, the outer diameter of the raised ridge is the inner diameter plus about from 0.020 to about 0.060 inches, and the thickness of the entire ridge is from about 0.005 to about 0.040 inches; the conical chamber has a volume that is at least 5 times the volume of a drop formed from the drop dispenser; the conical chamber has a volume of from 500 microliters to about 1000 microliters; the lower end of the sleeve member comprises means for engaging a container; the container comprises a resilient material; the container comprises one of a squeezable bottle, a squeezable vial, a squeezable tube, and a syringe; the nozzle is dimensioned and configured for delivering drops of the viscous liquid with each drop having a volume of about 25-40 microliters, the viscous liquid having a viscosity from about 100 to about 10,000 centipoises.