Flush mounted fastener for plasma processing apparatus
First Claim
1. A fastener assembly for use in a plasma processing chamber which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, the fastener assembly comprising:
- a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a non-cylindrical tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole;
a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and
a spring biasing the pin in the upper position, such that the pin is retractable from the upper position to the lower position when a tool is inserted in the tool engaging socket at the top of the through hole;
wherein the pin includes a rim between the spring and an axial end of the bolt, the rim engaging the axial end of the bolt when the pin is in the upper position.
1 Assignment
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Accused Products
Abstract
A fastener assembly for parts of a plasma chamber. The fastener assembly includes a bolt with a tool engaging socket and a spring-loaded pin which fits in a through hole of the bolt. When installed, the spring-loaded pin substantially fills the space in the socket and thus prevents parasitic plasma from forming in spaces between opposed surfaces of the pin and bolt. When a tool such as a hex key is inserted into the socket, the spring-loaded pin retracts and the tool rotates the bolt to attach an upper part to a lower part by engaging threads of the bolt with a threaded hole in the lower part.
31 Citations
11 Claims
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1. A fastener assembly for use in a plasma processing chamber which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, the fastener assembly comprising:
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a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a non-cylindrical tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole; a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and a spring biasing the pin in the upper position, such that the pin is retractable from the upper position to the lower position when a tool is inserted in the tool engaging socket at the top of the through hole; wherein the pin includes a rim between the spring and an axial end of the bolt, the rim engaging the axial end of the bolt when the pin is in the upper position. - View Dependent Claims (2, 4)
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3. A fastener assembly for use in a plasma processing chamber which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, the fastener assembly comprising:
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a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole; a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and a spring biasing the pin in the upper position; wherein the spring is a helical spring surrounding a lower section of the pin, the spring having a length greater than a length of the lower section of the pin and the pin includes a retention ring engaging at least one turn of the spring and a stop engaging an upper end of the spring when the spring is compressed.
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5. A fastener assembly for use in a plasma processing chamber which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, the fastener assembly comprising:
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a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole, wherein the bolt includes a top flange with an outer diameter of 0.38 inch and length of 0.08 inch, an unthreaded section extending from the flange having a diameter of 0.24 inch and length of 0.35 inch, and a threaded section extending from the unthreaded section having ISO screw threads of M6×
1 and length of 0.37 inch, andthe tool engaging socket comprises a hex socket extending from the top face having a length of 0.19 inch; a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and a spring biasing the pin in the upper position.
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6. A fastener assembly for use in a plasma processing chamber which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, the fastener assembly comprising:
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a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole; a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and a spring biasing the pin in the upper position; wherein the pin includes seven sections including a first section extending from the top face having a diameter of 0.11 inch and length of 0.21 inch, a second section extending from the first section having a diameter of 0.14 inch and length of 0.56 inch, a third section extending from the second section having a diameter of 0.12 inch and length of 0.03 inch, a fourth section extending from the third section having a diameter of 0.19 inch and length of 0.1 inch, a fifth section extending from the fourth section having a diameter of 0.13 inch and length of 0.05 inch, a sixth section extending from the fifth section having a diameter of 0.15 inch and length of 0.025 inch, and a seventh section extending from the sixth section having a diameter of 0.13 inch and length of 0.68 inch.
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7. A bolted assembly of a plasma chamber attached together with a fastener assembly which avoids parasitic plasma formation when used to attach parts inside the plasma chamber, comprising:
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an upper part having a stepped hole; a lower part having a blind hole with an upper threaded section and a lower unthreaded section; and a fastener assembly, comprising; a bolt having a tubular body with an axially extending center through hole, a threaded outer surface, and a tool engaging socket at the top of the through hole, the socket configured to engage a tool used to rotate the bolt during insertion of the bolt in a threaded hole; a pin having a shaft extending a length greater than a length of the through hole, the pin being movable from a lower position at which an upper portion of the through hole is not filled to an upper position at which a top face of the pin is flush with a top face of the bolt; and a spring biasing the pin in the upper position;
whereinthe bolt has a flange received in an upper section of the stepped hole, an unthreaded section received in a lower section of the stepped hole, a threaded section engaged with a threaded upper section of the blind hole; and the spring surrounds a lower section of the pin and is received in the lower section of the blind hole, the spring being compressed against a stop on the pin and pressing a rim of the pin against an axial end of the bolt when the pin is in the upper position. - View Dependent Claims (8, 9, 10, 11)
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Specification