Electrode and electrode holder with threaded connection

An electrode and electrode holder for a plasma arc torch, the electrode being removably held by the electrode holder in a threaded connection and comprising:

• an electrode holder having a female threaded portion defining at least one thread form extending helically and at least partially around a thread axis, the female threaded portion defining;
• a major diameter comprising a larger diameter of the female threaded portion,
• a minor diameter comprising a smaller diameter of the female threaded portion,
• an electrode having a male threaded portion defining at least one thread form for threadedly engaging the female threaded portion of the electrode holder, the male threaded portion defining;
• a major diameter comprising a larger diameter of the male threaded portion,
• a minor diameter comprising a smaller diameter of the male threaded portion,
• a pair of flanks defining one or more crest profiles when viewed in cross section and extending between the major diameter and the minor diameter, wherein each of the flanks of a crest profile defines at least one line that intersects at a crest apex with a line defined by the other of the flanks of that crest profile, and further wherein at least one of the lines intersects at a root apex with a line defined by a flank on an opposite side of the root apex, and
• a nominal pitch diameter defined halfway between the diameter of the crest apex and the diameter of the root apex;
• wherein the nominal pitch diameter of the electrode is not greater than the minor diameter of the electrode holder.

An electrode holder for removably holding an electrode in a plasma arc torch, the electrode holder comprising:

• a male threaded portion for removably holding the electrode holder in the plasma arc torch and defining at least one thread form extending helically and at least partially around a thread axis, the threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a pair of flanks defining one or more crest profiles when viewed in cross section and extending between the major diameter and the minor diameter, wherein each of the flanks of a crest profile defines at least one line that intersects at a crest apex with a line defined by the other of the flanks of that crest profile, and further wherein at least one of those lines intersects at a root apex with a line defined by a flank on an opposite side of the root apex, and
• a nominal pitch diameter defined halfway between the diameter of the crest apex and the diameter of the root apex;
• wherein the nominal pitch diameter is not greater than the minor diameter.

An electrode and electrode holder for a plasma arc torch, the electrode being removably held by the electrode holder in a threaded connection and comprising:

• an electrode holder having a threaded portion defining at least one thread form extending helically and at least partially around a thread axis, the threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a mean diameter between the major diameter and the minor diameter,
• a crest portion extending in one direction from the mean diameter,
• a root area extending in an opposite direction from the mean diameter than the crest portion and defining a width along the mean diameter, and
• an electrode having a threaded portion defining at least one thread form for threadedly engaging the threaded portion of the electrode holder, the threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a mean diameter between the major diameter and the minor diameter,
• a crest portion extending in one direction from the mean diameter,
• a root area extending in an opposite direction from the mean diameter than the crest portion and defining a width along the mean diameter, and
• wherein the width of the root area of the electrode is at least about 35% wider than the root area of the electrode holder.

An electrode for emitting an arc of a plasma arc torch and for being removably held to the plasma arc torch, the electrode comprising:

• a threaded portion for removably holding the electrode in the plasma arc torch and defining at least one thread form extending helically and at least partially around a thread axis, said threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a mean diameter between the major diameter and the minor diameter,
• a crest portion extending in one direction from the mean diameter and defining a width along the mean diameter, and
• a root area extending in an opposite direction from the mean diameter than the crest portion and defining a width along the mean diameter, and
• wherein the width of the root area is at least about 15% greater than the width of the crest portion.

An electrode holder for holding an electrode of a plasma arc torch and for being removably held to the plasma arc torch, the electrode holder comprising:

• a threaded portion for removably holding the electrode holder in the plasma arc torch and defining at least one thread form extending helically and at least partially around a thread axis, said threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a mean diameter between the major diameter and the minor diameter,
• a crest portion extending in one direction from the mean diameter and defining a width along the mean diameter, and
• a root area extending in an opposite direction from the mean diameter than the crest portion and defining a width along the mean diameter, and
• wherein the width of the root area is at least about 15% greater than the width of the crest portion.

A thread configuration of a plasma arc torch electrode for being threadedly engaged in a corresponding thread configuration in a plasma arc torch comprising:

• a threaded portion for threadedly holding the electrode within the plasma arc torch and defining at least one thread form extending helically and at least partially around a thread axis, the threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a mean diameter between the major diameter and the minor diameter,
• a crest portion extending in one direction from the mean diameter and defining a width along the mean diameter,
• a root area extending in an opposite direction from the mean diameter than the crest portion and defining a width along the mean diameter, and
• wherein the width of the root portion of the electrode is at least about 35% greater than the width of the root area of the corresponding thread configuration in the plasma arc torch.

An electrode and electrode holder for a plasma arc torch, the electrode being removably held by the electrode holder in a threaded connection and comprising:

• an electrode holder having a female threaded portion defining at least one thread form extending helically and at least partially around a thread axis, the threaded portion defining in cross section;
• a plurality of alternating crests and roots, the axial distance between corresponding points on two adjacent crests or roots defining a pitch;
• wherein at least one of the crests between adjacent roots defines a crest flat, and wherein the crest flat has a width in the axial direction that is greater than 0.4224 times the pitch;
• and
• an electrode having a male threaded portion defining at least one thread form for threadedly engaging the female threaded portion of the electrode holder, the threaded portion defining in cross section;
• a plurality of alternating crests and roots,
• wherein at least one the crests between adjacent roots defines a crest flat, and wherein the crest flat has a width in the axial direction that is less than width of the crest flat of the electrode holder.

An electrode for emitting an arc of a plasma torch and for being removably held in the plasma arc torch, the electrode comprising:

• a male threaded portion for removably holding the electrode within the plasma arc torch and defining at least one thread form extending helically and at least partially around a thread axis, the threaded portion defining;
• a major diameter comprising a larger diameter of the threaded portion,
• a minor diameter comprising a smaller diameter of the threaded portion,
• a pair of flanks defining one or more crest profiles when viewed in cross section and extending between the major diameter and the minor diameter, wherein each of the flanks of a crest profile defines at least one line that intersects at a crest apex with the line defined by the other of the flanks of that thread crest profile, and further wherein at least one of those lines intersects at a root apex with a line defined by a flank on an opposite side of the root apex;
• and
• a nominal pitch diameter defined halfway between the diameter of the crest apex and the diameter of the root apex;
• wherein the nominal pitch diameter is not greater than about 105% of the minor diameter.

A plasma arc torch comprising:

• a torch body;
• a nozzle attached to the torch body and defining a nozzle chamber extending from a larger proximal opening to a smaller distal exit orifice, the plasma arc being emitted through the exit orifice when the torch is in operation;
• an electrode defining a distal portion from which the arc is emitted and a proximal portion defining a male threaded portion for attaching the electrode to the plasma arc torch;
• and
• an elongate electrode holder connected to the torch body at one end and defining a female threaded portion at the other end for holding the electrode, the female threaded portion of the electrode holder and the male threaded portion of the electrode being engaged together along at least a portion of their respective lengths, wherein the engaged portion is positioned at least partially within the nozzle chamber when the torch is assembled.

An electrode holder for removably holding a consumable electrode in a nozzle chamber of a plasma arc torch, the electrode holder comprising:

• an elongate body having;
• a proximal end for being connected to the torch, and,
• an opposite distal end defining a female threaded portion for threadingly engaging the electrode,
• wherein the female threaded portion of the electrode holder is positioned at least partially within the nozzle chamber when the torch is assembled.

A method of manufacturing the body of an electrode for a plasma arc torch, the method comprising the steps of:

• forming an electrode blank from a base material and defining at least one external cylindrical surface;
• removing material from the cylindrical surface so as to define at least one helical thread form in the electrode blank, the removing step comprising the steps of;
• removing material so as to form flanks defining the thread form, the flanks defining at least one line when viewed in cross section that intersects at a crest apex with a line defined by another of the flanks and also intersects at a root apex with a line defined by yet another of the flanks, and
• discontinuing the removal of material at a depth from the cylindrical surface that is above a depth halfway between the root apex and the crest apex.