Counter balance spring assembly

• US 6,296,142 B1
• Filed: 06/07/1999
• Issued: 10/02/2001
• Est. Priority Date: 06/07/1999
• Status: Expired due to Term

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Nguyen, Son T.
• Primary Examiner(s): NEWHOUSE, NATHAN JEFFREY
• Application Number:
  US09/326,336
• Time in Patent Office: 848 Days
• Field of Search: 220/260, 220/263, 220/264, 220/827, 220/830, 220/828, 162/77, 162/86, 162/89, 162/90, 162/98--01, 163/06, 16/72, 493/86, 493/87, 312/319.4, 312/319.2, 206/710, 206/711
• US Class Current: 220/830
• CPC Class Codes: E05F 1/1058 for counterbalancing
• CPC Class Codes: E05Y 2900/608 for machines

Abstract

A counter balance assembly for a lid assembly comprising a spring inside a housing assembly. The counter balance assembly is mounted to a lid, whose displacement generates an external force substantially along a longitudinal axis of the spring. A restoring force is generated by the spring to counteract an inertia force arising from the lid displacement.

Claims

1. A counter balance assembly for a lid assembly comprising:

a spring disposed inside a housing mounted on a lid, wherein a restoring force acting upon said lid is generated by said spring in response to an external force created by a displacement of said lid from a reference position, said external force is directed substantially along a longitudinal axis of said spring, the restoring force is generated when said displacement of said lid exceeds a pre-determined displacement threshold with respect to said reference position of said lid; and

the reference position corresponds to a closed position of said lid and said pre-determined threshold is about 60°

of angular displacement of said lid from said closed position.

2. The counter balance assembly of claim 1, wherein said restoring force has a magnitude that increases with said displacement of said lid from said reference position.

3. The counter balance assembly of claim 1, wherein said restoring force counteracting against said lid displacement increases with said lid displacement.

4. The counter balance assembly of claim 1, wherein said restoring force is generated by compressing said spring.

5. A counter balance assembly for a lid assembly comprising:

a spring disposed inside a housing mounted on a lid;

wherein a restoring force acting upon said lid is generated by said spring in response to an external force created by a displacement of said lid from a reference position, said external force directed substantially along a longitudinal axis of said spring and a first torque about a lid pivot point is created by a first inertial force acting on said lid when said lid displacement exceeds a pre-determined threshold, a second torque is created by said restoring force to counteract said first torque, and

a resultant torque is given by a difference between said first and said second torques.

6.The counter balance assembly of claim 5, wherein said pre-determined displacement threshold is selected to maintain a net handle force required to counterbalance said resultant torque to be less than a pre-determined limit.

6. A counter balance assembly comprising:

a housing assembly having a top housing member mounted on a lid and a bottom housing member connected to said top housing member, where said bottom housing member is movable relative to said top housing member and having a predetermined angular displacement; and

a spring having a first end retained inside said bottom housing member and a second end retained in said top housing member;

said spring generating a restoring force acting against said lid in response to an external force which decreases said distance between said top housing member and said bottom housing member; and

said pre-determined angular displacement is about 60°

.

7. The counter balance assembly of claim 7, wherein said external force is generated when said lid is disposed to an angular displacement greater than a pre-determined value from a reference position of said lid.

8. A counter balance assembly comprising:

a housing assembly having a top housing member mounted on a lid and a bottom housing member connected to said top housing member, where said bottom housing member is movable relative to said top housing member;

said top housing member has a counterbored top opening connected to a second opening extending to a bottom surface of said top housing member;

said bottom housing member has a top opening extending partially into said bottom housing member and connecting with a tapped hole in the bottom housing member;

a spring having a first end retained inside said bottom housing member and a second end retained inside said top housing member;

said spring resides partly inside said second opening of said top housing member and partly inside said top opening of said bottom housing member;

said top and bottom housing members are connected by a screw having a head portion residing inside said counterbored top opening of said top housing member and a threaded end engaged to said tapped hole of said bottom housing member; and

said screw is disposed coaxially with said spring.

9. A wafer processing system comprising:

a lid mounted upon a chamber;

a counter balance assembly comprising a spring inside a housing assembly mounted on said lid, wherein said counter balance assembly generates a restoring force to counteract a first inertial force resulting from a lid displacement, and said restoring force is generated in response to an external force acting on said housing assembly in a direction substantially along a longitudinal axis of said spring when said lid displacement exceeds a pre-determined displacement threshold from a reference position;

said housing assembly and said chamber cooperate to generate said restoring force; and

said external force is generated when said housing assembly abuts against a wall of said wafer processing system and said restoring force arises from a compression of said spring.

10. The wafer processing system of claim 10, wherein a first torque is created by said first inertial force about a lid pivot point, a second torque is created by said restoring force acting about said lid pivot point, said first and second torques giving rise to a resultant torque which is less than said first torque, and said pre-determined displacement threshold is selected to maintain a net handle force required to counterbalance said resultant torque to be less than a pre-determined limit.

11. The wafer processing system of claim 11, wherein said pre-determined limit is about 22 lbs.

12. A wafer processing system comprising:

a lid mounted upon a chamber;

a counter balance assembly comprising a spring inside a housing assembly mounted on said lid;

wherein said counter balance assembly generates a restoring force to counteract a first inertial force resulting from a lid displacement, and a second restoring force is generated in response to an external force acting on said housing assembly in a direction substantially along a longitudinal axis of said spring when said lid displacement exceeds a pre-determined displacement threshold from a reference position;

said reference position corresponds to a closed position of said lid;

and said pre-determined displacement threshold is a displacement angle of about 60°

.

13. A wafer processing system comprising:

a lid mounted upon a chamber;

a counter balance assembly comprising a spring inside a housing assembly mounted on said lid;

wherein said counter balance assembly generates a restoring force to counteract a first inertial force resulting from a lid displacement; and

said restoring force is generated in response to an external force acting on said housing assembly in a direction substantially along a longitudinal axis of said spring when said lid displacement exceeds a predetermined displacement threshold from a reference position;

said housing assembly further comprises;

a top housing member having a counterbored top opening connected to a second opening extending to a bottom surface of said top housing member;

a bottom housing member having a top opening extending partially into said bottom housing member and connecting with a tapped hole in the bottom housing member;

said spring residing partly inside said second opening of said top housing member and partly inside said top opening of said bottom housing member;

said top and bottom housing members being connected by a screw having a head portion residing inside said counterbored top opening of said top housing member and a threaded end engaged to said tapped hole of said bottom housing member; and

said screw is disposed coaxially with said spring.