Cylinder having an internally-disposed drain valve
US4802402A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 14, 1986 |
| Grant date | Feb 7, 1989 |
| Priority date | — |
| Expiry date | Nov 14, 2006 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01B3/00
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A work cylinder having an internally-disposed, automatically-operated drain valve disposed in one or both ends of a housing having a cylinder bore formed therein. A reciprocally-movable piston divides the bore into first and second pressure chambers. A drain chamber formed in one or both ends has a movable plunger member disposed therein. A first passageway allows fluid from the pressure chamber to act on one surface of the plunger. A pilot valve is partially formed on a bottom portion of the plunger and opens when fluid pressure is exhausted from the adjacent pressure chamber. A bias spring acts on the plunger to prevent closing of the drain valve upon initial pressurization of the adjacent chamber. This initial pressurization assists in purging additional moisture from the chamber until a threshold level is exceeded to close the drain valve.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.