Fluid dispensing pump

A pump for dispensing small individual quantities of a viscous fluid, said pump comprising:

• a housing;
• tubular storage means for containing a supply of the viscous fluid to be dispensed, said tubular means having a first end and a second end, said second end being removably attached to said housing;
• a tubular shroud axially located within said tubular storage means, said shroud having a first and a second end, the second end of said shroud being coupled to said housing;
• a pump element positioned within an axial opening in the first end of said tubular storage means, said pump element being attched to the first end of said tubular shroud, said element sealing the first end of said tubular means and having an axial fluid dispensing hole therethrough;
• an axially movable plunger slideably extending through said tubular shroud, said plunger having a drive end within said housing and a tip end in said pump element, in a first position said tip end closely fitting within said axial fluid dispensing hole to block the escape of fluid from said storage means;
• drive means within said housing and including an axially movable spring biased diaphragm coupled to the drive end of said plunger for axially moving said plunger a predetermined distance to remove said tip end from its first position in said fluid dispensing hole to a second position to enable surrounding fluid within said storage means to flow to the void left by such plunger tip removal, said drive means further including means for applying pneumatic pressure to said diaphragm and against the loading of said spring for moving said plunger tip end from its first to second position, the release of said pneumatic pressure then returning said plunger tip to its first position to drive the fluid formed under said plunger tip through said fluid dispensing hole,
• said drive means includes a stroke adjustment means for adjusting the amount of axial movement of said plunger and the shot size of fluid to be ejected by said pump;
• piston means within said tubular storage means and overlying said viscous fluid for applying pressure to said fluid to force said fluid into the void created by the removal of said plunger tip from said first to said second position,
• wherein said piston means is urged against said fluid by pneumatic pressure applied through said housing into the second end of said tubular storage means;
• and
• the pump element attached to the first end of said tubular shroud included an axially spaced plunger bushing and ferrule, said ferrule having an axial opening and being mounted in an opening through the first end of said tubular container, the space between said ferrule said bushing having at least one radial side opening to permit the entry of fluid from said container.

A positive displacement pump for dispensing individual quantities of fluid from an associated fluid container, said pump comprising:

• a movable piston having a tip end and a drive end;
• a tubular shroud through which said piston may slideably move, said shroud having a first and second end;
• a ferrule attached to the first end of said tubular shroud, said ferrule having an input end coupled to said first shroud end and an output end for dispensing fluid, said ferrule having an opening between said input end and output end and coaxial with said movable piston, the input end of said ferrule opening accomodating the tip end of said piston for sealing said opening;
• at least one fluid input port through a wall of said shroud and adjacent the input end of said ferrule for admitting fluid thereto from an associated fluid container;
• a housing containing an axially movable spring biased diaphragm coupled to the drive end of said movable piston;
• means for applying pneumatic pressure into said housing to said diaphragm and against the loading of said spring for removing said piston tip from the opening in said ferrule and thereafter releasing the pneumatic pressure for driving said piston tip into said opening to dispense fluid therethrough,
• said drive means includes stroke adjustment means for adjusting the amount of axial movement of said plunger and the shot size of fluid to be ejected by said pump;
• piston means within said tubular storage means and overlying said viscous fluid for applying pressure to said fluid to force said fluid into the void created by the removal of said plunger tip from first to said second position,
• wherein said piston means is urged against the fluid by pneumatic pressure applied through said housing into the second end of said tubular storage means;
• and
• the pump element attached to the first end of said tubular shroud includes an axially spaced plunger bushing and ferrule, said ferrule having an axial opening and being mounted in an opening through the first end of said tubular container, the space between said ferrule and said bushing having at least one radial side opening to permit the entry of fluid from said container.