Vacuum-pressure-control slow exhaust valve
AssigneeSMC Corporation
InventorTsuneo Ishigaki
Life of this patent
Estimating the term…
Abstract
To reduce the axial length of a slow exhaust valve and thus the size of the valve, a secondary valve seat and a secondary valve body constituting a secondary valve mechanism for restrictively opening a channel connecting a chamber port and a pump port during the first half of the exhaust process in order to limit the exhaust speed are incorporated in a primary valve body in a primary valve mechanism; a secondary-valve-body drive mechanism and a pressure-acting secondary chamber are incorporated inside a primary-valve-body drive member in the primary valve mechanism; and a secondary shaft that connects the secondary valve body and the secondary-valve-body drive member together is disposed inside a primary shaft.
Claims5
A vacuum-pressure-control slow exhaust valve comprising a chamber port that is connected to a vacuum chamber, a pump port that is connected to a vacuum port, a primary valve mechanism that fully opens and closes a channel connecting both ports, and a secondary valve mechanism that restrictively opens and closes the channel connecting both ports,
- said primary valve mechanism having a primary valve seat disposed in the channel connecting both ports, a primary valve body that opens and closes the primary valve seat, a primary-valve-body drive member that uses fluid pressure to drive the primary valve body, and a primary shaft that connects said primary valve body and said primary-valve-body drive member,
- said secondary valve mechanism having a secondary valve seat having a smaller opening area than said primary valve seat, a secondary valve body that opens and closes the secondary valve seat, a secondary-valve-body drive member that uses fluid pressure to drive the secondary valve body, and a secondary shaft that connects said secondary valve body and said secondary-valve-body drive member together,
- wherein the secondary valve seat and said secondary valve body are incorporated in the primary valve body, wherein the secondary-valve-body drive member and a pressure-acting secondary chamber for allowing fluid pressure to act on the secondary-valve-body drive member are incorporated inside said primary-valve-body drive member and are not incorporated into said primary shaft, and wherein the secondary shaft penetrates the inside of the primary shaft.
Dependencies are inferred from the claim text.