510102 US Automatic Patriot Actuator Limit Nut

510102 US Automatic Patriot Actuator Limit Nut

The US Automatic 510102 is the Patriot actuator limit nut used in the travel-limit system of select Patriot swing gate linear actuator arms. The limit system is what allows the operator to stop the gate at the proper open and closed positions. If the limit nut is worn, damaged, stripped, or out of position, the actuator may stop in the wrong place, fail to reach full travel, overtravel, or show inconsistent limit behavior. Because the nut works together with the limit shaft, blue limit gear, limit switch assembly, and screw drive, it should be inspected as part of the full actuator limit mechanism rather than treated as an isolated hardware item. After replacement, the gate travel limits should be reset and tested through several cycles.

Compatible With

This compatibility list is based on known US Automatic Patriot service-part usage and should be verified against the original operator label, actuator parts diagram, and existing part number before ordering.

• US Automatic Patriot swing gate linear actuator arms
• Patriot heavy-duty swing gate openers using the original US Automatic actuator assembly
• Patriot single swing gate installations where the actuator parts diagram calls for this service part
• Patriot dual swing gate systems when each actuator uses the same matching service component
• Select older Patriot actuator assemblies when confirmed by the original part number and parts diagram

Also Known As / Related Part Numbers

• 510102
• US-510102
• USA 510102
• Patriot actuator limit nut
• Patriot cam nut
• Patriot limit cam nut
• limit nut for Patriot actuator
• 510105 related limit shaft
• 501105 related blue limit drive gear
• 510103 related limit switch assembly

Features & Specifications

Technician Note

If the limit nut has failed, inspect the entire limit system. A worn shaft, stripped gear, or misaligned limit switch assembly can cause the new nut to fail or produce inconsistent stopping points.

Before Ordering Checklist

• Confirm the actuator is a US Automatic Patriot swing actuator.
• Verify the old part is the limit nut, not the limit shaft or blue drive gear.
• Inspect the 510105 shaft and 501105 blue gear for wear.
• Inspect the 510103 limit switch assembly for damage or misalignment.
• Reset open and close limits after replacement and test several full cycles.

Professional Advisory

Internal actuator service can affect gate travel, limit adjustment, and safe stopping behavior. Disconnect power before service and have a qualified gate technician handle repairs if the actuator binds, the gate moves unexpectedly, or electrical damage is present.

Product Questions & Answers

What does the 510102 limit nut do?

It is part of the Patriot actuator limit system that helps control the open and closed stopping positions.

Is 510102 the complete limit switch assembly?

No. It is the limit nut only. The 510103 limit switch assembly and other related parts are separate.

Can this part fix a gate that will not stop correctly?

It may help if the original limit nut is worn or damaged, but the shaft, gear, switch assembly, and actuator travel should also be inspected.

Does the gate need to be re-adjusted after replacement?

Yes. The actuator travel limits should be reset and tested after limit-system service.

Is this used on Patriot RSL slide operators?

This content is written for the Patriot swing gate linear actuator limit assembly, not Patriot RSL slide operator limit parts.