Power transfer assembly for contact-start plasma arc torch

摘要

A power transfer assembly for a contact-start plasma arc torch conducts electrical current to an electrode through mating structures provided on two conductive elements. The mating structures are defined by sidewalls that are parallel to an assembly axis, and are configured to translatably engage each other, but are blocked from rotating with respect to each other. A compression and torsion spring serves to bias the conductive elements apart to bias the electrode to a forward position, and to apply a torsional load to the mating structures to maintain their sidewalls in contact. The mating structures can be provided by a shaped recess in one conductive element and a corresponding shaped protrusion extending from the other element. The spring can be secured to the conductive elements to maintain the components of the power transfer assembly together when the torch in which they are employed is disassembled.

主权项

1. A power transfer assembly for supplying electrical power to an electrode of a contact-start plasma arc torch, the power transfer assembly comprising:
a static element of conductive material having,
a static element spring-engaging bearing surface,a first mating structure defined by first mating structure sidewalls that are parallel to an assembly axis,a static element contact surface, anda static element spring end retainer; a movable element of conductive material having,
a movable element spring-engaging bearing surface,a second mating structure defined by second mating structure sidewalls that are parallel to the assembly axis,
said second mating structure being configured to translatably engage said first mating structure along the assembly axis when rotationally aligned therewith, but configured so as to be blocked from rotating with respect to said first mating structure when translatably engaged therewith,a movable element contact surface configured to be axially mateable against said static element contact surface,
said mating structures being configured to provide sufficient translational motion therebetween as to allow said movable element contact surface to be translated into contact with said static element contact surface, anda movable element spring end retainer; and a compression and torsion spring having,
a coil abutting against said spring-engaging bearing surfaces when said mating structures are translatably engaged with each other, and having a coil length LC such that said coil is compressed and applies a separation force to said spring-engaging bearing surfaces when said movable element contact surface is translated into contact with said static element contact surface,a spring first end configured to engage said static element spring end retainer so as to block rotation between said spring first end and said static element about the assembly axis, anda spring second end configured to engage said movable element spring end retainer so as to block rotation between said spring second end and said movable element about the assembly axis,
said compression and torsion spring being configured to engage said static element and said movable element in such a manner as to be torsioned when said mating structures are aligned with and translatably engaged with each other, thereby torsionally forcing said first mating structure sidewalls into contact with said second mating structure sidewalls along at least one line of contact.