Capacitor discharge process for welding braided cable

• US 5,457,301 A
• Filed: 12/02/1994
• Issued: 10/10/1995
• Est. Priority Date: 12/02/1994
• Status: Expired due to Fees

• Current Assignee: Department of Health and Human Services (State of Victoria)
• Original Assignee: The United States of America as represented by the Secretary of the Interior
• Inventors: Wilson, Rick D.
• Primary Examiner(s): Shaw, Clifford C.
• Application Number:
  US08/352,752
• Time in Patent Office: 312 Days
• Field of Search: 219/137 PS, 219/113, 219/127, 219/130.1, 219/56.1, 219/56.21, 219/56.22, 219/93, 219/95, 219/96, 228/138
• US Class Current: 219/137.0PS
• CPC Class Codes: B23K 9/1081 Arc welding by means of accumulated energy

Abstract

A capacitor discharge process for welding a braided cable formed from a plurality of individual cable strands to a solid metallic electrically conductive member comprises the steps of: (a) preparing the electrically conductive member for welding by bevelling one of its end portions while leaving an ignition projection extending outwardly from the apex of the bevel; (b) clamping the electrically conductive member in a cathode fixture; (c) connecting the electrically conductive member clamped in the cathode fixture to a capacitor bank capable of being charged to a preselected voltage value; (d) preparing the braided cable for welding by wrapping one of its end portions with a metallic sheet to form a retaining ring operable to maintain the individual strands of the braided cable in fixed position within the retaining ring; (e) clamping the braided cable and the retaining ring as a unit in an anode fixture so that the wrapped end portion of the braided cable faces the ignition projection of the electrically conductive member; and (f) moving the cathode fixture towards the anode fixture until the ignition projection of the electrically conductive member contacts the end portion of the braided cable thereby allowing the capacitor bank to discharge through the electrically conductive member and through the braided cable and causing the electrically conductive member to be welded to the braided cable via capacitor discharge action.

Claims

1. A capacitor discharge process for welding a braided cable formed from a plurality of individual cable strands to a solid metallic cylindrical, electrically conductive member, comprising the steps of:

(a) preparing said cylindrical, electrically conductive member for welding by bevelling an end portion of said cylindrical, electrically conductive member and leaving an ignition projection extending outwardly from the apex of said bevel;

(b) clamping said cylindrical, electrically conductive member in a cathode fixture;

(c) connecting said cylindrical, electrically conductive member clamped in said cathode fixture to a capacitor bank capable of being charged to a preselected voltage value;

(d) preparing said braided cable for welding by wrapping an end portion of said braided cable with a metallic sheet to form a retaining ring operable to maintain the individual strands of said braided cable in fixed position within said retaining ring;

(e) clamping said braided cable and said retaining ring as a unit in an anode fixture so that said wrapped end portion of said braided cable faces said ignition projection of said cylindrical, electrically conductive member; and

(f) moving said cathode fixture towards said anode fixture until said ignition projection of said cylindrical, electrically conductive member contacts said end portion of said braided cable thereby allowing said capacitor bank to discharge through said cylindrical, electrically conductive member and through said braided cable and causing said electrically conductive member to be welded to said braided cable via capacitor discharge action.

2. The capacitor discharge process as recited in claim 1, wherein a perpendicular cut is made across said braided cable prior to preparing step (d) to ensure that the cut end of said braided cable is substantially perpendicular to a side wall of said anode fixture upon completion of said clamping step (e).

3. The capacitor discharge process as recited in claim 2, wherein:

said metallic sheet is wrapped around said end portion of said braided cable so that said cut end of said braided cable extends above said metallic sheet; and

said cut end of said braided cable extending above said metallic sheet is ground away until said cut end of said braided cable is smooth and perpendicular to said side wall of said anode fixture.

4. The capacitor discharge process as recited in claim 1, wherein said braided cable and said retaining ring are ultrasonically cleaned prior to being clamped in said anode fixture.

5. The capacitor discharge process as recited in claim 1, wherein said end portion of said cylindrical, electrically conductive member has a bevelled end portion.

6. The capacitor discharge process as recited in claim 5, wherein said bevelled end portion has a 4 degree bevel.

7. The capacitor discharge process as recited in claim 1, wherein said metallic sheet and said braided cable are made from the same type of material.

8. The capacitor discharge process as recited in claim 7, wherein said metallic sheet and said braided cable are each made of copper.

9. The capacitor discharge process as recited in claim 1, wherein said cylindrical, electrically conductive member and said braided cable are each made of copper.

10. The capacitor discharge process as recited in claim 1, wherein said cylindrical, electrically conductive member and said braided cable are each made of steel.

11. The capacitor discharge process as recited in claim 1, wherein said cylindrical, electrically conductive member and said braided cable are each made of aluminum.