Spot welding cap changer with spring-driven rotary cap magazines
A mechanical cap changer that removes and installs spot-welding caps on pincer-type welding heads using a two-gripper extractor and two round, spring-driven cap magazines. The extractor uses opposing pivoting jaws that clamp caps for a combined rotational and axial pull-off; each magazine is a circular carrier that advances caps one-by-one against a stop by spring force. Intended users include fabricators and manufacturers that service pincer spot-welding heads on robots or stationary welders.
(57) What the patent covered
This write-up was generated by AI from the patent's text and may contain mistakes, so check it against the original patent before relying on it.
The main independent claim covered a cap magazine comprising a round cap carrier with multiple holes whose bottoms prevent caps passing through, spot-welding caps that protrude above the carrier surface, and a spring drive that advances the carrier (without directly contacting the caps) so each protruding cap portion bears against a stop at an access position for axial attachment to a pincer shaft and extraction, and that the spring advances the next cap when one is removed. It also covered a spot-welding cap changer combining that magazine with a gripper extractor.
Distinguishing feature: A spring-driven circular cap carrier that advances oriented caps one-by-one to a fixed stop so caps can be axially attached to a pincer shaft and extracted without relying on gravity.
Novelty 4/5. Spring-driven indexed magazines and multi-jaw grippers existed, but applying a round, bottomed hole carrier with a protruding-cap stop and a spring box for reliable indexing to short-shaft pincer heads addressed a specific installation problem.
Manufacturing
Machined or stamped steel carrier (circular plate with holes), heat-treated/hardened steel jaws and gripper parts, wound coil spring in a spring box, subassembly by bolting and simple hand fitting; possible plating or heat treatment for wear resistance.
Materials: Stamped or machined steel for carrier and stop, spring steel for the spring box, hardened steel for jaws/gripper teeth, wear-resistant alloy or copper for welding caps.
Manufacturability 4/5. Several stamped/machined metal parts plus a wound spring and pivot assemblies; requires moderate tooling (stamps, CNC, spring winding) and hand assembly of gripper and magazine parts.
Market demand
Comparable products are on sale; this exact design was not found. Multiple vendors offer automated cap changers and cap dressers for resistance spot welding; many listings are marketing pages or solution providers without public pricing; several units support magazine-based cap feeding and pull/rotate-off actions.
- Electrode Cap Changer · SVS Schweißtechnik GmbH (via SVS America distributor listing)
- Tip Former & Cap Changer · Mino Automation USA, Inc.
- Automatic Tip Changer (KIKK Cap Changer) · Kyokutoh (via G.E. Schmidt / Kyokutoh partnership page)
Demand check by web search, week of Oct 12, 2026. Listings change frequently.
Buyers: Maintenance or tooling engineers for spot-welding cells.
Before manufacturing
No related continuation or divisional patents in force were found. Design patents, trademarks and unrelated patents may still cover the product.
Patent has lapsed; practical issues include wear of jaws and caps, need for precise indexing and stops, and compatibility with varied pincer shaft geometries and short access distances.
About 1.5% of lapsed patents are later revived by their owners. This page is a research lead, not legal advice. Obtain a freedom-to-operate opinion before manufacturing.