Patent Description:
Some conventional torch systems (e.g., plasma arc torch systems) include one or more electrical and gas delivery lead lines having torch lead connectors to transfer electrical current, seal liquid/gas connections, and/or provide a securing method between a torch and a power supply. Traditionally, a torch receptacle is located at a distal end of the lead opposite the power supply, the torch receptacle for connecting the torch to the lead and including a set of discrete connections for each of gas, coolant, etc., which are connected one at a time, each one being screwed and/or fastened together independently. Some conventional torch receptacles utilize distinct threaded connectors to achieve these connections. In some cases, some plasma torch power supplies have multiple distinct threaded connections to fluidly and electrically connect a torch to the power supply via a lead and torch receptacle. Having a set of discrete connections such as this makes installation and maintenance difficult and time consuming, requiring an experienced and knowledgeable technician to even disconnect or reconnect the torch lead to the system.

In a first aspect, the invention discloses a plasma torch head for a liquid-cooled plasma cutting system according to claim <NUM>.

In a second aspect, the invention discloses a method of aligning and coupling a plasma torch head for a liquid-cooled plasma cutting system to a torch receptacle of a plasma torch lead according to claim <NUM>.

Advantageous embodiments are disclosed in the dependent claims.

Embodiments described herein can have one or more of the following advantages.

Plasma arc cutting systems can include torches that must be periodically disconnected and/or replaced for maintenance and operation related purposes. Removing the torch head allows for consumable changes and torch care to be accomplished in a cleaner environment, which can result in better performance and reliability. Removal and installation of such torch heads can be a complicated process that requires the individual disconnection and reattachment of multiple hoses, leads, and passageways. Some conventional plasma torch platforms having removable torch heads attempt to address the complicated attachment processes to allow for quick consumable changes, resulting in less downtime. However, such conventional plasma torch platforms with removable torch heads can typically still require longer times to install or remove the torch head from the torch receptacle due to inconvenient or difficult component alignment techniques.

Whereas, the systems and methods described herein can provide one or more advantages over some of the conventional devices. For example, the systems and methods described herein can include systems and features for both coarse and fine radial alignment of components, as well as coarse and fine rotational alignment (e.g., circumferential, angular orientation, or clocking alignment) of components that can make the torch faster and easier to fully align with a torch lead/torch receptacle. The torch systems can also include connectors having multiple start threads to provide for faster and easier engagement. The improved quick disconnect systems described herein can involve several stages of alignment prior to engaging the mechanical coupling feature itself. In some embodiments, mechanical coupling is achieved with a multi-start thread, which can provide multiple thread connection points.

<CIT> and <CIT> disclose examples of plasma torch heads and their connections to torch receptacles.

In some aspects, plasma torch heads include multiple alignment features that can be configured to provide multi-stage alignment of the torch head to a complementary torch receptacle of a torch lead during assembly. Additionally, the alignment features can be implemented for coarse and fine alignment of the torch head in both radial directions and rotational directions. Using such multi-stage alignment can help to make the connection faster and easier to make.

Referring to <FIG> and <FIG>, a torch head <NUM> to connect a plasma torch to a plasma torch lead (via a torch receptacle) can include a base portion (e.g., a structural body) <NUM> configured to be coupled to the torch receptacle of the plasma torch lead. The base portion <NUM> includes or defines a set of ports to convey one or more fluids, gases, or electrical currents or signals from the power supply system to the torch. The set of ports can include one or more fluid passageways (e.g., defined by tubing members) or standoffs or posts to facilitate an electrical connection. For example, the set of ports can include one or more coolant ports, such as a coolant supply port <NUM> and a coolant return port <NUM>, one or more electrical connections, such as an ohmic contact connector <NUM> and a pilot arc contact connector <NUM>, and one or more gas ports, such as a plasma gas port <NUM>, and a shield gas port <NUM>. In some embodiments, as discussed below, one or more of the ports can be configured to provide a combination of services to the torch to support plasma arc generation, such as transferring a combination of coolant and electrical current. In some embodiments, the base portion <NUM> defines a front face <NUM> from which the set of ports extend.

The coolant supply port <NUM> is centrally located within the base portion <NUM> and configured to convey a liquid coolant from the liquid-cooled plasma cutting system (via the torch lead) to a plasma arc torch connected to the torch head. As discussed in detail below, the substantially central location of the coolant supply port <NUM> can be helpful to center the torch head <NUM> within the torch receptacle during installation and connection. The coolant supply port <NUM> can also be configured to convey (e.g., deliver, conduct) an operational current, such as a plasma cutting current, from the liquid-cooled plasma cutting system to the plasma arc torch. For example, in some cases, the side wall of the coolant supply port <NUM> can be conductive to conduct the electrical current.

The coolant return port <NUM> can define a passage to convey return liquid coolant from the plasma arc torch to the plasma torch lead. For example, the coolant return port <NUM> can define a substantially cylindrical side wall that encloses a fluid passage.

The torch head <NUM> includes at least one plasma processing gas supply port to convey processing gases from the liquid-cooled plasma cutting system to the plasma arc torch, such as a plasma gas port <NUM> and a shield gas port <NUM>. In some embodiments, the gas supply ports can include one or more bullet plugs for connecting different gases/gas supplies to the torch.

The coolant or gas connections can include one or more seals within the torch head or the receptacle. For example, in some embodiments, the coolant supply port <NUM>, the gas supply ports <NUM>, <NUM>, and the coolant return port <NUM> include o-ring sealing members. In some cases, threads of the connector <NUM> (discussed below) are configured to engage with the torch lead receptacle before the o-ring sealing members engage with their complementary ports. As discussed herein configurations and locations of the various ports can be designed to reduce interference, increase flow rates, help align components, increase creepage and clearance distances, thermally and/or electrically isolate channels, and achieve various other objectives. In some embodiments, once installed, o-ring sealing members can be substantially static connections, unlike some conventional systems.

Electrical contacts, such as the ohmic contact connector <NUM> and the pilot arc contact connector <NUM> are arranged and configured to convey current to and from the torch. In some embodiments, the ohmic contact connector <NUM> is integrated into the torch lead line and connects with the power supply through the torch head-to-torch receptacle connection.

The set of ports is shaped to align/guide alignment of the torch head and the plasma torch receptacle during connection. As discussed below, the torch head can be configured to have multi-stage alignment having a coarse (e.g., first) and fine (e.g., second) radial alignment (e.g., to align the central axes of the torch head and torch receptacle) and a coarse and fine rotational (e.g., circumferential, or clocking) alignment. According to the invention, a primary alignment is a coarse radial alignment, a secondary alignment is a coarse rotational alignment, and a tertiary alignment is a fine rotational alignment.

According to the invention, the central coolant supply port <NUM> extends a first length from the base portion to serve as a primary coarse radial alignment to center the torch head <NUM> with respect to the plasma torch receptacle <NUM>. For example, the central coolant supply port <NUM> can be inserted into a complementary port of the receptacle <NUM>. However, due to looser tolerances, there may still be some radial play such that the two components can be adjusted relative to one another.

The central coolant supply port <NUM> also includes an additional alignment feature , i.e. a flat surface <NUM> shaped to secondarily align (primarily in a rotational/circumferential manner) the torch head with the torch receptacle upon mating engagement. The secondary alignment is a coarse rotational alignment. The flat surface <NUM> is defined or disposed along an outer surface of a cylindrical portion of the coolant supply port <NUM>. The flat surface <NUM> can be arranged substantially parallel to a longitudinal axis of the coolant supply port <NUM>. Additionally, the flat surface <NUM> can be arranged to face (e.g., be normal to) about <NUM> degrees to about <NUM> degrees (e.g., about <NUM> degrees) away from a coolant return port <NUM> relative to a central axis of the base portion. While the flat surface <NUM> has been generally described as being arranged at about <NUM> degrees, any of various other configurations are possible. That is, the angular orientation can vary and be any of various other angles when matched by a complementary feature of the receptacle.

The central coolant supply port <NUM> can additionally include or define an outer surface at or near a proximal region 104A of the central coolant supply port that is configured to finely radially align the plasma torch head with the torch receptacle as the torch head advances into the torch receptacle. As discussed above, a tip or radial end of the central coolant supply port <NUM> can be used to coarsely align the torch head with the receptacle, for example, upon initial installation and as the torch head becomes fully installed in the torch receptacle, as detailed below, the proximal region of the central coolant supply port can finely align (e.g., centralize) the torch head within the torch receptacle.

Another port is the ohmic contact connector <NUM> and defines a tertiary fine rotational alignment feature. For example, the ohmic contact connector <NUM> can engage first but after the coarse engagements of other components, such as the coolant supply port <NUM>. That is, the engagement and alignment can occur in sequence to that the ohmic contact connector <NUM> engages before all of the other bullet connectors and is the first of all the fine connectors to engage. The ohmic contact connector <NUM> is used as the tertiary alignment because it is typically rugged, typically not subject to much relative movement during use, and can handle stresses. Additionally, another connector pin, or a simple alignment pin, could be used as a tertiary alignment feature.

The ohmic contact connector <NUM> can extend from the base portion <NUM> to a second length that is greater than the first length. In some cases, the length of the ohmic contact connector is greater than lengths of other ports extending from the base portion <NUM>. Having a greater length can help the ohmic contact connector <NUM>, which can be used for alignment, engage the torch receptacle before any other outer ports (e.g., after the central coolant supply port <NUM>). For example, the length of the ohmic contact connector <NUM> can be at least about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) (e.g. about <NUM> (<NUM> inches)) greater than lengths of the other ports.

In some embodiments, the torch head <NUM> connection points, such as the coolant ports <NUM>, <NUM>, electrical connections <NUM>, <NUM>, and gas ports <NUM>, <NUM> are arranged at various off-center (e.g., asymmetrical) locations about the torch head-to-torch receptacle interface. For example, the coolant return port <NUM> can be disposed at about -<NUM> degrees to about <NUM> degrees (e.g., <NUM> degrees). That is, with respect to example angular orientations, the coolant return port <NUM> can serve as a reference point from which the orientations of other ports can be measured or defined. The ohmic contact connector <NUM> can be disposed at about <NUM> degrees to about <NUM> degrees (e.g., <NUM> degrees). The shield gas port can be disposed at about <NUM> degrees to about <NUM> degrees (e.g., <NUM> degrees). The processing gas supply port <NUM> can be disposed at about <NUM> degrees to about <NUM> degrees (e.g., <NUM> degrees). The pilot arc connector <NUM> can be disposed at about <NUM> degrees to about <NUM> degrees (e.g., <NUM> degrees). Additionally, unless otherwise stated herein, given angular dimensions or definitions can include tolerances of up to about +/- <NUM> degrees. Further, angular dimensions can include an angular position at which a port is substantially centered, or an angular position at which any portion of the port is disposed.

By way of an example only, a torch head can be configured and arranged such that the coolant return port <NUM> is disposed at <NUM> degrees relative to a central axis of the base portion (e.g., the central axis can be defined or arranged along the coolant return port and the coolant supply port); the ohmic contact connector can be disposed at about <NUM> degrees relative to the central axis of the base portion; the shield gas port <NUM> can be disposed at about <NUM> degrees relative to the central axis of the base portion; the first processing gas supply port <NUM> can be disposed at about <NUM> degrees relative to the central axis of the base portion; and the pilot arc connector <NUM> is disposed at about <NUM> degrees.

In some embodiments, the pilot arc contact <NUM> and the first plasma gas port <NUM> are each located adjacent to the coolant return port <NUM>. In some embodiments, a second gas supply port (e.g., the shield gas supply port <NUM>) can be disposed between the first plasma gas port <NUM> and the coolant return port <NUM>. In some cases, the pilot arc contact <NUM> and the ohmic contact <NUM> are disposed on opposite sides of the coolant return port <NUM>. The ports can be arranged in this manner to achieve various design goals. In some cases, arranging ports in an alternating manner, such as fluid ports disposed next to (e.g., in between) electrical ports can be useful for thermal and/or electrical isolation.

The torch head <NUM> can also include a connector (e.g., fastener) <NUM> disposed about the base portion <NUM>. The connector <NUM> is configured to engage (e.g., couple, affix, attach, or otherwise connect) the base portion <NUM> to the torch receptacle of the torch lead and to operably connect the various ports, including each of the coolant supply <NUM>, the coolant return <NUM>, the gas supply ports <NUM>, <NUM>, and the electrical connections <NUM>, <NUM>, to respective complementary connections of the torch receptacle of the liquid-cooled plasma cutting system upon coupling to the liquid-cooled plasma cutting system. In some embodiments, the connector <NUM> can include a threaded member (e.g., a threaded nut) configured to be threaded onto a threaded portion of the receptacle. In some embodiments, the connector can include or define a multi-start thread along an interior surface. The multi-start thread can be configured to matingly engage a complementary multi-start thread on an exterior surface of the torch receptacle.

In some embodiments, the connector <NUM> is shaped to matingly engage the torch receptacle <NUM> prior to operable connection of each of the ohmic contact connector, the coolant supply port, and the at least one plasma processing gas supply port. That is, in some cases, while the alignment features can align each port with the complementary ports of the torch receptacle, they may not be fully operably engaged (e.g., sealed) until the connector engages the torch receptacle.

Referring to <FIG>, the systems described herein (e.g., the torch head <NUM> and the torch receptacle <NUM>) can be used to carry out various methods of multi-stage alignment and coupling of a plasma arc torch head (e.g., the torch head <NUM>) for a liquid-cooled plasma cutting system to a component of a torch lead (e.g., the torch receptacle <NUM>) of the liquid-cooled plasma cutting system. In some examples, as discussed below, the systems described herein can be used to carry out a multi-stage process having a coarse placement and fine adjustment of the radial position of the torch head and also a coarse placement and fine adjustment of the angular/rotational position of the torch head within the torch receptacle.

Methods include providing a plasma torch head (e.g., torch head <NUM>) having a base portion (e.g., the base portion <NUM>) defining a set of ports configured to receive fluids and/or electrical signals from a plasma torch lead via a plasma torch receptacle, the set of ports being shaped to align the torch head and the plasma torch receptacle during connection.

As depicted in <FIG>, the methods include inserting a central coolant supply port (e.g., the coolant supply port <NUM>) of the set of ports into a central coolant opening <NUM> of the torch receptacle to coarsely radially align the plasma torch head with the torch receptacle. For example, coarse radial alignment can include a loose fit between receptacle cathode OD and torch insulator ID.

Referring to <FIG>, the methods also include rotating the plasma torch head <NUM> relative to the torch receptacle <NUM> to align an alignment feature (i.e. the flat surface <NUM>) of the central coolant supply port <NUM> with a complementary feature <NUM> of the torch receptacle to coarsely rotationally (e.g., clockingly, circumferentially) align the plasma torch head <NUM> with the torch receptacle <NUM> (features <NUM> and <NUM> limiting or preventing axial advancement of torch head <NUM> relative to torch receptacle <NUM> until they are aligned).

For example, the torch head <NUM> can be rotated relative to the torch receptacle so that the cathode flat can be aligned with torch cathode flat. Additionally or alternatively, with the torch head coarsely rotationally aligned with the torch receptacle, the torch head can be finely radially aligned, for example, by fitting the proximal region 104A of the central coolant supply port <NUM> within a complementary portion 204A of the torch receptacle. To provide for a finer radial alignment, in some examples, a tolerance or fit between the proximal region 104A and the complementary portion 204A can be tighter than that of the coolant supply port <NUM> and the central coolant opening <NUM>. With the torch head finely rotationally aligned with the torch receptacle, the torch head can be further inserted into the torch receptacle.

In some cases, the rotating the plasma torch head <NUM> relative to the torch receptacle to align the flat surface <NUM> of the central coolant supply port <NUM> with the complementary feature <NUM> of the torch receptacle <NUM> is performed after the inserting of the central coolant supply port <NUM> of the set of ports into the central coolant opening of the torch receptacle <NUM> and before the rotating the plasma torch head <NUM> relative to the torch receptacle to align the ohmic contact connector <NUM> extending from the base portion with the opening within the torch receptacle.

Referring to <FIG>, after or during inserting the plasma torch head <NUM> into the torch receptacle <NUM>, the methods include rotating the plasma torch head <NUM> relative to the torch receptacle <NUM> to align an ohmic contact connector <NUM> with a complementary port <NUM> of the torch receptacle <NUM> to finely circumferentially align the torch head with the torch receptacle to align other ports of the set of ports with complementary ports of the torch receptacle. In some cases, this amount of rotation may be small (e.g., a small degree of rotation). For example, the fine alignment and rotation can include a rotation of less than about <NUM> degrees (e.g., less than about <NUM> degree). That is, while the flat <NUM> may have initially aligned the two components, with a certain amount of slack or tolerance, the ohmic contact connector <NUM> can seat within the port <NUM> of the torch receptacle to finely rotationally align the torch head within the torch receptacle. This fine rotation can be caused by the torch itself during installation. That is, the fine rotational alignment can, in some cases, not be noticeable to the end use. At this point in the alignment, the torch can take over and drive final alignment.

Additionally, the torch head <NUM> is further inserted into the torch receptacle <NUM> to bring a torch threaded connector disposed about the base portion of the torch head (e.g., the connector <NUM> of torch head <NUM>) into contact with the torch receptacle. With all of the ports substantially aligned, the torch head <NUM> is inserted into the torch receptacle so that they can be coupled together. That is, the methods additionally include engaging the torch threaded connector (e.g., connector <NUM>) to couple the torch head <NUM> to the torch receptacle <NUM> to establish connections between the set of ports of the torch head with complementary ports of the torch receptacle. In some examples, the engaging the torch connector <NUM> to couple the torch head to the torch receptacle can include rotating a multi-start thread connector about the base portion.

While certain alignment procedures and sequences have been described, the systems described herein can be used to align and couple the torch in other orders. For example, the coarse rotational alignment can occur before, during, or after the fine radial alignment and positioning of the torch head within the torch receptacle. That is, the torch head can be inserted into the torch receptacle and axially pushed inwardly while it is adjusted radially and angularly to make all of the required alignment adjustments. In practice, the positional adjustments for the various coarse and fine alignments may occur without the awareness of the user. That is, the user may just insert the torch head into the torch receptacle and gently shake or jiggle the respective components relative to one another and the multi-stage alignment features can align the ports as the torch head seats within the torch receptacle. But while the specific sequences may go unnoticed by the user, the considerable convenience and faster and easier connection processes can be observed and appreciated.

Claim 1:
A plasma torch head (<NUM>) for a liquid-cooled plasma cutting system, the plasma torch head comprising:
a base portion (<NUM>);
a set of ports disposed within the base portion and configured to receive fluids and/or electrical signals from a plasma torch lead via a plasma torch receptacle, the set of ports being shaped to align the plasma torch head and the plasma torch receptacle during connection, the set of ports including:
a central coolant supply port (<NUM>) defining a passage to convey a liquid coolant to the plasma torch head, the central coolant supply port extending a first length from the base portion to provide primary coarse radial alignment of the plasma torch head with the torch receptacle, the central coolant supply port further including a flat surface (<NUM>) shaped to provide a secondary coarse rotational alignment of the plasma torch head with the torch receptacle upon mating engagement,
at least one plasma processing gas supply port (<NUM>) to convey a plasma processing gas to the plasma torch head, and
an ohmic contact connector (<NUM>) defining a fine tertiary rotational alignment feature; and
a threaded connector (<NUM>) disposed about the base portion configured to matingly engage the torch receptacle to couple the plasma torch head to the torch receptacle.