Resistance welding fastener electrode

• US 7,282,664 B2
• Filed: 05/31/2005
• Issued: 10/16/2007
• Est. Priority Date: 07/10/2001
• Status: Expired due to Term

• Current Assignee: Doben Limited
• Original Assignee: Doben Limited
• Inventors: Cabanaw, Daniel Martin
• Primary Examiner(s): Kerns; Kevin P.
• Application Number:
  US11/140,682
• Publication Number:
  US 20050224468A1
• Time in Patent Office: 868 Days
• Field of Search: 219/119, 219/117.1, 219/93, 219/109
• US Class Current: 219/119
• CPC Class Codes: B23K 11/253 the measured parameter being a displacement or a position
• CPC Class Codes: B23K 11/315 with one electrode moving on a linear path

Abstract

A welding assembly is provided for welding a fastener to an object such as a vehicle body panel. The assembly includes a weld gun having first and second electrodes movable relative to one another between an open position and a closed position. The first electrode includes a housing assembly. A pin is received in the housing assembly and is movable when in said closed position between a desired nut position, and upside down nut position, and a no nut position. An optical sensor has a terminal end space from the pin for direction light thereon. The terminal end of the sensor received reflected light from the pin. A sensor control system processes the reflected light into a signal corresponding to one of the desired nut, upside down nut, and no nut positions.

Claims

1. A welding assembly for welding a fastener to an object, the assembly comprising:

a weld gun having first and second electrodes movable relative to one another between an open position and a closed position;

a weld gun component movable in said closed position between at least one of a desired fastener position and an undesired fastener position;

an optical sensor directing light on said weld gun component with the said light reflecting from said weld gun component; and

a sensor control system processing said reflected light into a signal corresponding to at least one of said desired fastener position and said undesired fastener position.

2. The welding assembly according to claim 1, wherein said first electrode is a stationary lower electrode with an actuator moving said second electrode toward said first electrode to said closed position.

3. The welding assembly according to claim 1, wherein said weld gun component is a pin.

4. The welding assembly according to claim 1, wherein a terminal end of the optical sensor receives reflected light from said weld gun component.

5. The welding assembly according to claim 1, wherein said undesired fastener position comprises an upside down fastener position and a no fastener position.

6. A method of resistance welding a fastener comprising the steps of:

a) loading a fastener;

b) closing opposing weld gun electrodes about the fastener; and

c) measuring the displacement of the weld gun component associated with the movement of the electrodes.

7. The method according to claim 6, including directing light onto a weld gun component associated with movement of the electrodes and measuring reflected light from the weld gun component to determine displacement of the electrodes.

8. The method according to claim 6, wherein the weld gun component is the pin.

9. The method according to claim 6, preceding step a) including the step of inserting the pin into an aperture in the object.

10. The method according to claim 6, including the step of indicating one of a desired fastener position and an undesired fastener position.

11. The method according to claim 10, including the step of generating a weld gun fault for the undesired fastener position.