Electric heating – Metal heating – By arc
Reexamination Certificate
2001-11-09
2004-03-30
Paschall, Mark (Department: 3742)
Electric heating
Metal heating
By arc
C219S121540, C219S121510, C219S121590, C219S137630
Reexamination Certificate
active
06713711
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to quick disconnects and more particularly to quick disconnects for use between a power supply and a torch lead in a plasma arc torch through which both fluid (e.g. gas, liquid) and electrical power are conducted.
BACKGROUND OF THE INVENTION
In manually operated plasma arc torches of the known art, a torch is commonly connected to a power supply through a torch lead, which is typically available in a variety of lengths according to requirements of a specific application. Additionally, the torch lead is often secured to the power supply using a quick disconnect such that the torch lead may be quickly and easily removed from the power supply in the event that the torch and/or torch lead is damaged or requires replacement. Further, the quick disconnect allows a torch and torch lead to be easily interchanged with a variety of power supplies if necessary.
Typically, the torch lead side of the quick disconnect comprises a housing, commonly in the form of a plug, with a variety of electrical and fluid, (e.g., gas, liquid), conductors disposed therein. Similarly, the power supply side of the quick disconnect also comprises a housing, commonly in the form of a socket, adapted to receive the plug, with a mating set of electrical and gas conductors disposed therein. Generally, the mating conductors comprise one or more main power pins and mating sockets that conduct both electric power and fluid for operation of the torch, wherein high current, high voltage, and/or high frequency electrical power is provided to initiate and operate a plasma arc. Further, a plurality of signal pins and mating signal sockets conduct electrical signals for operation of the torch such as a trigger switch or electrical grounding, among others. Moreover, some or all of the mating conductors, including the main power pins and sockets, may be replaceable such that an inoperative or broken conductor may be replaced in the field as necessary.
The majority of quick disconnects that connect a plasma arc torch lead to a power supply comprise a threaded connection between the torch lead side of the connection and the power supply side of the connection. Typically, a locking ring is disposed around one housing or the other, and after the individual conductors and the housings are engaged, internal threads of the locking ring engage external threads of one of the housings, typically the socket housing, to secure the connection therebetween. Unfortunately, the quick disconnects of the known art comprise a relatively fine pitch thread that requires several turns of the locking ring in order to fully engage the quick disconnect. Additionally, no indication of a fully mated condition of the quick disconnect is provided in connectors of the known art. Rather, a user tightens the locking ring until the locking ring cannot be turned any further. Moreover, it is often difficult to properly engage the threads to initiate a connection since the threads must generally be aligned, in addition to aligning the conductors within the housings, which often causes a significant amount of rotation of the locking ring to initiate threaded contact. Engagement is particularly difficult and time consuming when the threads of the locking ring and the housing comprise a finer pitch. To simplify threaded contact, known art connectors have employed coarser threads in order to facilitate ease of connection. However, a finer pitch generally results in a more robust and reliable connection and thus the coarser threads reduce the robustness and reliability of the connection. Accordingly, a trade-off exists between ease of connection and a robust and reliable connection in threaded connectors of the known art.
Therefore, quick disconnects for plasma arc torches of the known art are typically heavy and bulky in order to accommodate the multitude of electrical and gas conductors disposed therein. As a result, connecting and disconnecting a torch lead to and from a power supply is often cumbersome and difficult in the field. Further, proper alignment of the individual fluid and electrical conductors disposed within each side of the quick disconnect becomes more difficult with the heavy and bulky quick disconnects. Moreover, the use of a threaded connection between the housings, especially when the threads comprise a finer pitch, results in an even more difficult quick disconnect to engage and disengage.
Additionally, the conductors of known art quick disconnects are often prone to damage when the quick disconnect is disengaged since the conductors often extend or protrude beyond the ends of their respective housings. Further, when a conductor is damaged or broken in the field, an improper conductor may inadvertently be used to replace the damaged conductor such that unsuitable equipment, e.g. torches, are mistakenly connected to the power supply. As a result, the torch may function improperly or parts may wear prematurely. In addition, the torch can be damaged or operate improperly when disengaging quick disconnects of the known art as all of the connections are typically broken simultaneously, or in some instances, the gas continues to flow even when the quick disconnect is not fully engaged. Consequently, the plasma arc torch may become damaged or difficult to operate should an inadvertent disengagement of the quick disconnect occur during operation of the torch.
Accordingly, a need remains in the art for a quick disconnect for use between a power supply and a plasma arc torch that is relatively compact and easy to engage, and which further provides a positive indication of a fully mated condition. A further need exists for a quick disconnect that reduces the risk of damage to the conductors disposed therein and that reduces the risk of replacing a damaged conductor with an improper conductor, thereby improving the performance of a plasma arc torch. Moreover, a need exists for a quick disconnect that reduces the risk of arcing and that prevents damage to the plasma arc apparatus when a quick disconnect is not fully engaged.
SUMMARY OF THE INVENTION
In one preferred form, the present invention provides a quick disconnect for use between a power supply and a torch lead in a plasma arc apparatus such as a plasma arc cutting torch, hereinafter referred to as a plasma arc torch. Generally, the quick disconnect provides a connection for both fluid, (e.g., gas, liquid), flow and electrical power between the power supply and the torch, while providing a connection that may be quickly engaged and disengaged in the field. Further, as used herein, a plasma arc apparatus, whether manual or automated, shall be construed by those skilled in the art to be an apparatus that generates or uses plasma for cutting, welding, spraying, or marking operations, among others. Accordingly, the specific reference to plasma arc cutting torches or plasma arc torches herein should not be construed as limiting the scope of the present invention.
According to one form of the present invention, the quick disconnect comprises a plug housing secured to a torch lead that engages a socket housing secured to a power supply, wherein a locking ring disposed around the plug housing engages the socket housing to secure the plug housing to the socket housing. Alternately, the plug housing may be secured to the power supply, and the socket housing may be secured to the torch lead. Further, a plurality of both fluid and electric conductors are disposed within the plug and socket housings, which include but are not limited to, a negative lead gas carrying pin secured within the plug housing, or alternately the socket housing, that engages a main power socket secured within the socket housing, or alternately the plug housing. In addition, a plurality of signal pins are disposed within the plug housing, or alternately the socket housing, that engage a plurality of signal sockets disposed within the socket housing, or alternately the plug housing. Moreover, a pilot return pin is disposed within the plug housing, or alternately the socket
Adams Stewart Trent
Conway Christopher J.
Demers Douglass A.
Jones Joseph P.
MacKenzie Darrin H.
Harness & Dickey & Pierce P.L.C.
Paschall Mark
Thermal Dynamics Corporation
LandOfFree
Plasma arc torch quick disconnect does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Plasma arc torch quick disconnect, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Plasma arc torch quick disconnect will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3238778