Hose pump for the exact dosing of small quantities of liquids

An improved hose pump for dosing precise quantities of fluid comprising:

• a rotary-driven roller holder,
• a plurality of rotatable rollers housed on the roller holder in a pitched circle,
• a hose bed having a contoured surface facing the roller holder, each of said roller holder, rotatable rollers and hose bed being arranged such that the roller holder moves the rollers about an orbital path at a distance from the contoured face of the hose bed, said distance being such that the rollers can compress through a portion of the orbital path thereof a hose which, during operation of the pump, is placed between the hose bed and the orbital path of the rollers, through a portion of the orbital path thereof, and
• a control means for controlling the quantity of fluid dispensed, which is achieved through (a) adjusting an angle defined by the roller bed with respect to the hose bed, wherein angle adjustments influence the quantity of fluid dispensed and (b) the time elapsed since the previous dispensing of fluid so as to compensate for fluid losses which may have occurred,
• wherein the contour of the hose bed is offset from the orbital path of the rollers so that the distance between the hose bed and the orbital path of the rollers increases in the direction of movement of the rollers until the rollers reach a point where they are capable of exerting a minimum of compression on said hose.