US Patent 8377043 Fluid delivery apparatus with bellows reservoir

A compact fluid dispenser for use in controllably dispensing fluid medicaments, such as, antibiotics, analgesics, and like medicinal agents from the device reservoir which is provided in the form of a novel bellows type assembly. The fluid dispenser includes a unique stored energy mechanism which takes the form of a constant force spring member of novel design that provides the force necessary to continuously and substantially uniformly expel fluid from the device reservoir. The device also includes novel adjustable flow rate control assembly that is disposed intermediate the fluid reservoir outlet and the outlet port of the device for precisely controlling the rate of fluid flow from the outlet port toward the patient.