Patent ID: 8640921

Claim:
A device for dispensing a fixed dose of fluid, the device comprising: at least one barrel; at least one plunger at least partially enclosed within the barrel; a motion conversion mechanism for transferring actuated pressure force applied outside the barrel into movement of the at least one plunger in a dispensing direction, wherein the motion conversion mechanism comprises at least one rotating gear, wherein the motion conversion mechanism comprises at least one rotatable cylindrical threaded shaft connected directly or indirectly to the at least one plunger; and a releasing mechanism for disconnecting the plunger from the motion conversion mechanism, wherein at a released position the at least one plunger can move in a direction opposite to the dispensing direction, independent of a rotational movement of the at least one gear, and wherein the movement of the plunger in the opposite direction to the dispensing enables loading the fluid into the barrel, wherein the releasing mechanism comprises a split nut attached to the at least one plunger, wherein the split nut engages the cylindrical threaded shaft and rotates along the cylindrical threaded shaft and the operation of the releasing mechanism comprises opening the split nut to enable free movement of the plunger.