Fluid activated load operator
US3936977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1973 |
| Grant date | Feb 10, 1976 |
| Priority date | — |
| Expiry date | Dec 27, 1993 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE05Y2900/132
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A door operator includes a double acting power cylinder with a dual metering valve mounted thereon. The valve unit includes an external tube with a sliding control piston coupled to the power cylinder for corresponding selected movement. A pair of spaced metering assemblies are secured to the tube and each includes a supply-exhaust port connected through a four-way valve means to an air supply and an exhaust, and connected to provide air flow to and from opposite end heads of the power cylinder. Each assembly has a one-way supply passageway, a central speed control passageway and a fixed damping passageway. The latter two passageways each have a small needle valve control and the speed control passageway is selectively blocked by the control piston. The power and damping cylinder assembly includes a mounting enclosure with the controls therein and with the power cylinder piston rod pivotally connected to a tubular drive arm. An adjustable excursion rod adjustably telescopes into the drive arm and in turn is pivotally interconnected to a second positioning rod. A pivotal mounting bracket is adjustably secured to the outer end of the positioning rod for attachment to the door. The li…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.