Main valve
First Claim
1. A main valve located at an opening for connecting a vacuum chamber and a main vacuum pump, said main valve comprising:
- a valve seat for opening and closing said opening, said valve seat being larger than said opening;
at least one cylinder connectable to said valve seat for raising and lowering said valve seat; and
a driving source for driving said cylinder,said cylinder comprising a cylindrical housing, a rod having one end extending through s aid cylindrical housing and being connectable to said valve seat and at another end a piston housed in said cylindrical housing, a nut coupled to said piston, a ball screw having a threaded portion coupled within said nut and a lower portion connectable to said driving source for rotating said ball screw which drives said nut, said piston, said rod, and said valve seat forward and backward to open and close said opening,wherein said rod has a cavity therein and a part of said threaded portion of said ball screw projects through said nut and said piston and is housed in said cavity in said rod.
1 Assignment
0 Petitions
Accused Products
Abstract
A bridge-type main valve located at a connecting outlet between a vacuum chamber and a main vacuum pump, and having a rod of an electric cylinder driven by a stepper motor connected to a valve seat for opening and dosing the connecting outlet so that the driving direction and a closing surface of the valve seat form a right angle. A piston may be attached to the rod, and a cylindrical housing fitted in the piston so that the piston and the cylindrical housing form a pressurized air pumping chamber for moving the rod and the valve seat in the outlet closing direction. The valve can achieve fine pressure adjustment without any variable orifice by stopping a valve seat at an arbitrary (not stepwise) position.
20 Citations
14 Claims
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1. A main valve located at an opening for connecting a vacuum chamber and a main vacuum pump, said main valve comprising:
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a valve seat for opening and closing said opening, said valve seat being larger than said opening; at least one cylinder connectable to said valve seat for raising and lowering said valve seat; and a driving source for driving said cylinder, said cylinder comprising a cylindrical housing, a rod having one end extending through s aid cylindrical housing and being connectable to said valve seat and at another end a piston housed in said cylindrical housing, a nut coupled to said piston, a ball screw having a threaded portion coupled within said nut and a lower portion connectable to said driving source for rotating said ball screw which drives said nut, said piston, said rod, and said valve seat forward and backward to open and close said opening, wherein said rod has a cavity therein and a part of said threaded portion of said ball screw projects through said nut and said piston and is housed in said cavity in said rod. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
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2. A main valve located at an opening for connecting a vacuum chamber and a main vacuum pump, said main valve comprising:
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a valve seat for opening and closing said opening, said valve seat being larger than said opening; at least one cylinder connectable to said valve seat for raising and lowering said valve seat; and a driving source for driving said cylinder, said cylinder comprising a cylindrical housing, a rod having one end extending through said cylindrical housing and being connectable to said valve seat and at another end a piston housed in said cylindrical housing, a nut coupled to said piston, a ball screw having a threaded portion coupled within Said nut and a lower portion connectable to said driving source for rotating said ball screw which drives said nut, said piston, said rod, and said valve seat forward and backward to open and close said opening, wherein said cylinder is connectable to one end of said valve seat and another end of said valve seat is connectable to an edge of said opening. - View Dependent Claims (3, 4, 5, 14)
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Specification