Low height precompression pump
View Patent ↗A low height precompression pump having a piston with a lower outwardly flaring lip seal and an inwardly flaring lip seal rimming a central aperture of the piston, and which may include a first elastic member housed in the cylinder and a second elastic member having an upper bearing point applied directly on the plunger rod above an upper retention cover.
1. A precompression pump, comprising:
a cylinder defining a pump chamber;
an inlet valve in communication with the pump chamber;
a piston, comprising:
a lower outwardly flaring lip seal in sliding engagement with an interior wall of the pump chamber; and
an inwardly flaring lip seal rimming a central aperture of the piston;
a pump plunger rod;
an interior communication passage in the pump plunger rod;
a plug mounted in at least a portion of the interior communication passage of the pump plunger rod;
a projecting part of the plug outside the interior communication passage and comprising a diameter greater than a diameter of the pump plunger rod;
a first elastic member bearing against the cylinder and the plug; and
a second elastic member bearing against the piston and the pump plunger rod.
2. The precompression pump of claim 1 , wherein a portion of the plug mounted in at least a portion of the interior communication passage of the pump plunger rod is flat.
3. The precompression pump of claim 1 , wherein the projecting part of the plug comprises a cup shape.
4. The precompression pump of claim 1 , wherein the pump plunger rod, the inwardly flaring lip seal of the piston, and the plug form a hermetic seal.
5. The precompression pump of claim 1 , wherein the first elastic member comprises a helicoidal spring.
6. The precompression pump of claim 1 , wherein the second elastic member comprises a helicoidal spring.
7. The precompression pump of claim 1 , wherein the second elastic member is integral with the pump plunger rod.
8. A precompression pump, comprising:
a cylinder defining a pump chamber;
a piston at least partially contained within the pump chamber, comprising:
a lower outwardly flaring lip seal in sliding engagement with an interior wall of the pump chamber;
a central aperture; and
an inwardly flaring lip seal rimming the central aperture;
a pump plunger rod in sliding engagement with the central aperture of the piston;
an interior communication passage in the pump plunger rod;
a plug mounted in at least a portion of the interior communication passage of the pump plunger rod;
a projecting part of the plug outside the interior communication passage;
a first helicoidal spring bearing against a bottom portion of the cylinder and the plug;
a second helicoidal spring bearing against the piston and a portion of the pump plunger rod;
an upper retention cover over an upper portion of the cylinder; and
a retainer positioned between the retention cover and the piston.
9. A precompression pump, comprising:
a cylinder defining a pump chamber;
an inlet valve in communication with the pump chamber;
a piston, comprising:
a lower outwardly flaring lip seal in sliding engagement with an interior wall of the pump chamber; and
an inwardly flaring lip seal rimming a central aperture of the piston;
a pump plunger rod;
an interior communication passage in the pump plunger rod;
a plug mounted in at least a portion of the interior communication passage of the pump plunger rod;
a projecting part of the plug outside the interior communication passage;
a first helicoidal spring bearing against the cylinder and the plug;
a second helicoidal spring bearing against the piston and the pump plunger rod; and
an upper retention cover, wherein the second helicoidal spring bears against the pump plunger rod above the upper retention cover.
10. The precompression pump of claim 9 , wherein a portion of the plug mounted in at least a portion of the interior communication passage of the pump plunger rod is flat.
11. The precompression pump of claim 9 , wherein the projecting part of the plug comprises a cup shape.
12. The precompression pump of claim 9 , wherein the projecting part of the plug comprises a diameter greater than the diameter of the pump plunger rod.
13. The precompression pump of claim 9 , wherein the pump plunger rod, the inwardly flaring lip seal of the piston, and the plug form a hermetic seal.
14. The precompression pump of claim 9 , wherein the helicoidal spring member is integral with the pump plunger rod.
15. The precompression pump of claim 9 , further comprising a retainer positioned in an upper end of the cylinder between the retention cover and the piston.