Container-mounted pump means with external restoring spring

A pump means adapted to be mounted on a liquid container comprising:

• a nozzle head including a pressing cap formed on a top portion of a pipe, a discharge tube protruding outwardly from said pressing cap and fluidically communicated with said pipe, an upper plunger valve formed in said pipe, and a fastening member formed on a lower portion of said pipe;
• a piston including a hollow piston rod and a fastening portion formed on a top portion of said piston rod to be engaged with said fastening member of said nozzle head for securing said nozzle head with said piston;
• a liquid accumulator mounted in an upper portion of said liquid container, having said piston operatively reciprocating in said accumulator;
• a fastening ring secured on an upper portion of said accumulator;
• a container cap secured on a top portion of said liquid container and fastened between the fastening ring and a flange formed on an upper portion of the accumulator;
• a restoring spring normally restoring said nozzle head and said piston upwardly;
• a suction tube connected to said accumulator;
• and
• a lower plunger valve formed in a lower portion of said accumulator;
• the improvement which comprises:
• said restoring spring resiliently held between an upper sleeve portion protruding downwardly from said fastening member of said nozzle head and an annular groove annularly recessed in a lower sleeve portion of said fastening ring;
• said restoring spring disposed about said piston rod and positioned outside said piston and said accumulator without contacting a liquid as pumped through said accumulator;
• and said fastening ring having a cylindrical chamber concentrically defined between said lower sleeve portion of said fastening ring and said piston rod for receiving said restoring spring and said upper sleeve portion of said nozzle head into said cylindrical chamber when downwardly depressing said pressing cap of said nozzle head for compressing said spring.