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US 5,469,776 AGranted
Hydraulic pumping device
AssigneeDanfoss A/S
InventorsLars Martensen, Ove T. Hansen, Henry M. Moeller, Hardy Jepsen
Life of this patent
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Abstract
A hydraulic pumping device for use in a hydraulic machine having a piston and slider shoe unit made of a combination of plastic and metal material to operate with virtually lubricant free fluid.
Claims16
A hydraulic pumping device for use with virtually lubricant free fluid comprising:
- a metal cylinder;
- a piston and slider shoe unit, said unit comprising a plastic piston and a metal slider shoe operatively connected to said plastic piston, said plastic piston slidable within said metal cylinder;
- a plastic control surface, said plastic control surface engaging said metal slider shoe whereby said plastic piston is reciprocated in said metal cylinder upon movement of said plastic control surface;
- and
- a plastic support for securing said metal slider shoe in engagement with said plastic control surface, said plastic support engaging said metal slider shoe.
2 more elements
A hydraulic pumping device for use with virtually lubricant free fluid comprising:
- a plastic cylinder;
- a metal piston and plastic slider shoe unit, said unit comprising a metal piston and a plastic slider shoe operatively connected to said metal piston, said metal piston slidable within said plastic cylinder;
- a metal control surface, said metal control surface engaging said plastic
- slider shoe whereby said metal piston is reciprocated in said plastic cylinder upon movement of said metal control surface;
- and
- a metal support for securing said plastic slider shoe in engagement with said metal control surface, said metal support engaging said plastic slider shoe.
3 more elements
Dependencies are inferred from the claim text.