Handling: hand and hoist-line implements – Grapple – Expanding
Reexamination Certificate
2000-04-28
2001-06-19
Cherry, Johnny D. (Department: 3652)
Handling: hand and hoist-line implements
Grapple
Expanding
C294S099100
Reexamination Certificate
active
06247737
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to manufacture of semiconductor crystals and in particular to maintenance of pulling chambers of crystal-growing machines.
Semiconductor crystals are formed in machines including furnaces in which the semiconductor material is liquified. Each machine includes a pulling chamber several feet high, located above the furnace. Crystals are gradually pulled upward through the pulling chamber from melted semiconductor material. Concentric gas flow areas are defined in the pulling chamber, and a purge tube and parts related to such gas flow areas periodically need to be removed from the pulling chamber, cleaned, and replaced.
In the past, pulling chamber components have been disassembled, removed, and replaced by lifting each part by hand. Some of these parts, however, are of costly, fragile, or brittle materials such as graphite. With technology developing to permit and make it desirable for larger crystals to be formed, purge tube parts have become large enough and heavy enough that it is difficult for a single person to handle the pulling chamber components safely. As a result, the risk of damage to parts of a pulling chamber or of injury to the personnel working with such parts has increased. What are needed, then, are tools for use in handling certain parts of a semiconductor crystal growing machine, and an improved method for handling such parts safely and conveniently.
SUMMARY OF THE INVENTION
The present invention supplies an answer to the above-identified needs by providing a specialized cart, a connector system, and tools which can be connected conveniently to a lifting chain, cable, or similar tension-carrying member controlled by a hoist, and a method for disassembly, removal of parts, and reassembly of a purge tube portion of a pulling chamber of a semiconductor crystal-growing machine.
The method of the present invention for handling portions of a pulling chamber of a semiconductor crystal-growing machine includes the steps of attaching a tension-carrying member to a purge tube ring removal tool, raising the ring removal tool into engagement with a purge tube ring, releasing the purge tube ring from the pulling chamber, and extending the tension-carrying member to lower the ring removal tool and purge tube ring beneath the pulling chamber.
Other aspects of the method of the invention may include steps of using a purge tube-engaging device to engage a purge tube, raising the purge tube-engaging device and the purge tube together within the pulling chamber, and removing a purge tube holding ring from the pulling chamber while holding the purge tube in an elevated position.
The method according to the invention may also include a step of lowering a purge tube ring removal tool carrying a purge tube ring onto a cart located beneath the pulling chamber.
Yet another aspect of a method according to the present invention may include the step of engaging a purge tube holding ring at two opposite locations on a bottom surface of the purge tube holding ring by using a purge tube holding ring removal tool, and supporting the purge tube holding ring with such a tool while removing it from the pulling chamber.
The present invention provides an easily operated connector for attaching a tension-carrying member such as a hoist cable to an object to be lifted. Such a connector includes a latch pin disposed slidably in a pair of inclined slots defined in side walls of a receptacle. The slots are inclined downward and rearward toward a rear wall of the receptacle so that the latch pin moves along the slots to grasp a tapered finger attached to the top of an object to be lifted when the receptacle is placed on the finger. Upward force applied to the receptacle results in the latch pin being urged into tighter engagement against the tapered finger, yet the connector is easily released by moving the receptacle downward relative to the tapered finger and moving the latch pin upward and away from the rear wall of the receptacle.
The present invention also provides a ring tool including a horizontal support ring carried by a structure including upwardly-extending legs located within the area circumscribed by the horizontal support ring, thus centralizing a tubular part such as a purge tube ring. The tool thus safely carries such a tubular part safely, centering it about the legs and within the horizontal support ring.
Preferably, parts of such a tool are covered by a heat-resistant cushioning material.
The invention also provides another tool for handling a tubular item within a limited space. Such a tool includes a pair of legs each having a respective foot attached to a lower end thereof, with upper ends of the legs being interconnected with each other by a resilient member. A flexible tension-bearing member is preferably attached to the tool at two spaced-apart locations near the upper ends of the legs, where it can be used to pull the feet closer together to permit the tool to be passed through a tubular or annular item. Thereafter, tension can be relaxed to allow the feet to move apart beneath the tubular or annular item to engage and support or lift it.
Another aspect of the present invention provides a specially adapted cart for use during assembly or disassembly of a pulling chamber of a semiconductor crystal-growing machine. The cart has a deck supported by wheels of which at least some are able to swivel to permit the cart to be moved easily into a desired location. The cart also includes at least one jack to engage a surface beneath the cart to hold the cart in a required location. The cart according to one embodiment of the present invention may also include a set of steps rising above the deck to support a person assembling or disassembling the pulling chamber. In a preferred embodiment of the invention such a cart may include one or more handrails located adjacent such a set of steps, for use by a person assembling or disassembling a pulling chamber.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
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Alston & Bird LLP
Cherry Johnny D.
SEH America Inc.
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