Syringe pump drive system and disposable syringe cartridge

In a syringe pump, the combination comprising:

• a syringe cartridge having a cylinder, a piston and a piston rod;
• a pair of outwardly extending mounting bosses on said cylinder;
• a drive system for linearly reciprocating said piston and said piston rod within said cylinder;
• a pair of integral, outwardly extending mounting bosses adjacent a cut-away portion of said piston rod;
• a coupling shoe connected between said drive system and said piston rod, said coupling shoe having a pair of upstanding flanges containing a pair of oppositely disposed, confronting guide slots and a retention channel extending therebetween, said guide slots being adapted to receive said mounting bosses with the longitudinal axis of said syringe cartridge horizontal, enable rotation of said syringe cartridge to a position wherein said longitudinal axis is substantially vertical, and restrain said syringe cartridge against horizontal or vertical dislocation relative to said mounting shoe when said longitudinal axis is vertical;
• and
• a syringe receiving compartment having a pair of oppositely disposed sidewalls, said sidewalls having defined therein a pair of confronting guide slots adapted to engage, guide and subsequently retain said mounting bosses projecting from said cylinder.

In a syringe pump, the combination comprising:

• a hollow syringe cylinder having an open end and a closed end, said cylinder being adapted for normal use with its longitudinal axis substantially vertical, said cylinder having a pair of inlet and outlet nipples projecting from said closed end of said cylinder, there being no valves within said nipples, the uppermost interior surface of said cylinder being sloped, said outlet nipple being located adjacent the highest point of said interior surface within said cylinder, said cylinder having
• a pair of outwardly extending mounting bosses;
• a syringe piston head within said cylinder;
• a syringe piston rod connected to said piston head for reciprocating said piston head along said longitudinal axis of said cylinder, said piston rod having a pair of outwardly extending mounting bosses adjacent a partially cut-away portion of said piston rod;
• a flexible sealing cap overlying and encasing said piston head, said cap defining an upwardly directed conical piston face, the slope of said conical face substantially conforming to the slope of said interior surface of said cylinder, said sealing cap further defining a pair of axially spaced apart sealing rings in engagement with the interior surface of said cylinder, said sealing cap having a limp membrane skirt adapted to seal said open end of said cylinder without stretching at any time during reciprocation of said piston head, said piston rod and said sealing cap, said skirt terminating in a thickened bead portion adapted to grip the external surface of said cylinder and prevent said sealing cap from being dislodged;
• a syringe receiving compartment having a pair of oppositely disposed sidewalls, said sidewalls having defined therein a pair of confronting guide slots adapted to engage, guide and subsequently retain said mounting bosses projecting from said cylinder;
• a drive system for linearly reciprocating said piston and said piston rod, said piston rod having a pair of outwardly extending mounting bosses adjacent a cut-away portion of said piston rod;
• and
• a coupling shoe connected between said drive system and said piston rod, said coupling shoe having a pair of upstanding flanges containing a pair of oppositely disposed, confronting guide slots and a retention channel extending therebetween, said guide slots being adapted to receive said mounting bosses with the longitudinal axis of said syringe horizontal, enable rotation of said syringe to a position wherein said longitudinal axis is substantially vertical, and restrain said syringe against horizontal or vertical dislocation relative to said mounting shoe when said longitudinal axis is vertical.