The HEAD-LOCK is a quick-release tie-down for Mitchell base heads. It eliminates the separate knob with 3/8" stud for securing the head. Instead, the HEAD-LOCK mounts to, and stays on, the bottom of the head, using a 3/8"-16 bolt. When the head is placed on the dolly or tri-pod, the HEAD-LOCK passes through the center of the Mitchell mount. Turning the built-in knob from below locks the head in place. There's no more fishing around, trying to get the tie-down started, while the sun is dropping below the horizon.

The HEAD-LOCK is made of anodized aluminum, stainless steel and plated steel parts. The only non-plated steel parts, the thrust washer and it's races, are hardened steel and packed in grease. The HEAD-LOCK is built for long life & low maintenance.

Important: Do not try to tighten the HEAD-LOCK onto a Mitchell mount unless the HEAD-LOCK is bolted to the bottom of a camera head, or the mounting bolt is through the HEAD-LOCK with a nut tightened down on it. Doing so could pull the moving parts of the HEAD-LOCK out of the center hub.

Important: When mounting the HEAD-LOCK on the camera head, be sure the head of the mounting bolt goes into the rubber seal in the center of the tightening knob. When properly installed, the head of the bolt will be flush with the face of the knob.

Safety Catch: For extra security, one of the three jaws on your Head-Lock has a spring plunger screwed into it, so the HEAD-LOCK could never vibrate loose and the head fall of its mount. When you are loosening the knob and retracting the jaws, you will feel resistance when the spring plunger reaches the center hub. Continuing to turn the knob will overcome this resistance, and the jaws will retract into the hub. The amount of resistance can be adjusted by inserting a small screwdriver into the threaded hole and turning the spring plunger.

Lubrication: Under normal working conditions, lubrication of the HEAD-LOCK is something you should rarely have to deal with. There are two groups of moving parts:

1. The jaws and their associated parts are nickel plated and their surfaces work well against each other. To help them work smoothly, they have been sprayed with a dry film lubricant, one that contaminants will not stick to. If you want at some point in time to re-treat these surfaces, you can do that without disassembling the HEAD-LOCK. the three screws that hold the base plate to the center hub are in threading holes that go all the way through the hub to the parts that drive the jaws. Using a spray can that has a plastic tube attached to the nozzle, put the tube all the way into the hole and give it one quick shot of lubricant. Do this in each hole and then rotate the knob to spread the lubricant.
2. 
   Below the head of the mounting bolt, behind the rubber seal, is a thrusting bearing that is packed with light-weight grease. If this area gets contaminated, for example if the HEAD-LOCK is submerged in water, the area will need to be cleaned and the bearing re-greased. To access the bearing, remove the retaining ring and rubber seal.