Consumable Cartridge For A Plasma Arc Cutting System

• US 20150319835A1
• Filed: 05/11/2015
• Published: 11/05/2015
• Est. Priority Date: 11/13/2013
• Status: Active Grant

• Current Assignee: Hypertherm Incorporated
• Original Assignee: Hypertherm Incorporated
• Inventors: Sanders, Nicholas A., Twarog, Peter J., Shipulski, E. Michael, Zhang, Yu
• Granted Patent: US 9,981,335 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23K 10/00 Welding or cutting by means of a plasma
• CPC Class Codes: B23K 10/006 Control circuits therefor circuits for plasma torches H05H1/36
• CPC Class Codes: H05H 1/34 Details, e.g. electrodes, nozzles
• CPC Class Codes: H05H 1/3457 Nozzle protection devices
• CPC Class Codes: H05H 1/3489 Means for contact starting
• CPC Class Codes: H05H 1/3494 Means for controlling discharge parameters

Abstract

The invention features a replaceable cartridge for a plasma arc torch. The cartridge includes a cartridge body having a first section and a second section. The first and second sections are joined at an interface to form a substantially hollow chamber. The interface provides a coupling force that secures the first and second sections together. The cartridge also includes an arc constricting member located in the second section; an electrode included within the substantially hollow chamber; and a contact start spring element affixed to the electrode. The spring element imparts a separating force that biases the electrode toward at least one of the first section or the second section of the body. The separating force has a magnitude that is less than a magnitude of the coupling force.

Claims

1. A replaceable cartridge for a plasma arc torch, the replaceable cartridge comprising:

a cartridge body having a first section and a second section, the first and second sections joined at an interface to form a substantially hollow chamber, the interface providing a coupling force that secures the first and second sections together;

an arc constricting member located in the second section;

an electrode included within the substantially hollow chamber; and

a contact start spring element affixed to the electrode, the spring element imparting a separating force that biases the electrode toward at least one of the first section or the second section of the body, the separating force having a magnitude that is less than a magnitude of the coupling force.

2. The replaceable cartridge of claim 1 wherein a gas input moves the electrode and overcomes the separating force.

3. The replaceable cartridge of claim 1 wherein at least a portion of the electrode and the contact start spring element are irremovably disposed within the substantially hollow chamber.

4. The consumable cartridge of claim 1 wherein a base of the arc constricting member is anodized.

5. The cartridge of claim 1 wherein the cartridge has a region with a thermal conductivity of between about 200-400 Watts per meter per degree Kelvin.

6. The consumable cartridge of claim 5 wherein the shield has a heat capacity to current ratio of 2-4 W/m-°

K-A.

7. The consumable cartridge of claim 1 further comprising a cap insert connected to the second section of the cartridge body, the cap insert substantially orienting the electrode and retaining the electrode within the cartridge body.

8. A sealed cartridge unit for a plasma arc torch, the cartridge unit comprising:

a substantially hollow frame including a first substantially hollow portion defining a first end and a second substantially hollow portion defining a second end;

an arc emitter located within the frame, the arc emitter translatable relative to the frame;

an arc constrictor attached to the second end of the frame; and

a resilient element in physical communication with the frame, the resilient element biasing the arc emitter toward one of the first end or the second end to facilitate ignition at or near the arc emitter.

9. The cartridge unit of claim 8 wherein a gas input moves the electrode and overcomes the separating force.

10. The cartridge unit of claim 8 wherein the frame includes an electrical insulator.

11. The cartridge unit of claim 8 wherein the frame includes at least one of a metal or a strongly thermally conductive material.

12. The cartridge unit of claim 8 wherein the frame is anodized.

13. The cartridge unit of claim 8 further including at least one set of flow holes, each flow hole in the set of flow holes radially offset from the other flow holes.

14. The cartridge unit of claim 13 wherein the flow holes have a total cross-sectional area of about one square inch.

15. The cartridge unit of claim 8 wherein the first end is configured to connect to a shield via a shield insulator, the shield, the arc constrictor and the frame being thermally coupled.

16. The cartridge unit of claim 8 wherein the cartridge unit has a region with a thermal conductivity of between about 200-400 Watts per meter per degree Kelvin.

17. The cartridge unit of claim 8 further comprising a cartridge cap disposed in the second end of the frame, the cartridge cap shaped to contact the arc emitter and to retain the arc emitter within the frame.

18. A replaceable, unitary consumable assembly for a plasma arc torch, the consumable assembly comprising:

a gas flow diverter;

an arc constrictor in physical communication with the gas flow diverter;

an emissive member disposed substantially within the gas flow diverter and the arc constrictor; and

a resilient arc initiator disposed between the emissive member and at least one of the gas flow diverter or the arc constrictor, at least a portion of each of the gas flow diverter, the arc constrictor, the emissive member and the arc initiator irremovably integrated within the consumable assembly.

19. The consumable assembly of claim 18 wherein the emissive member includes an electrode and the arc starter includes a spring.

20. The consumable assembly of claim 18 wherein the gas flow diverter is anodized.

21. The consumable assembly of claim 18 wherein the gas flow diverter includes a cap insert located substantially opposite the arc constrictor, the cap insert substantially orienting the emissive member and retaining the emissive member within the gas flow diverter.

22. The consumable assembly of claim 21 further comprising a seal disposed within the cap insert.

23. The consumable assembly of claim 18 further comprising a shield connected to the gas flow diverter.

24. The consumable assembly of claim 23 wherein the shield is connected to the gas flow diverter via a shield insulator.