Installation is the same as for other types of shanks available; the top is removed and the top of the customer's ring is soldered into place. The large variety of sizes available facilitates this procedure.

The button on the locking trigger fits securely into the hole on the grooved piece. This makes a positive lock that cannot accidentally come open; it can only be opened by physically lifting the trigger button out of the hole.

Lockshank®
Installation Instructions

1. Determine the correct size for customer's finger at the place the ring will be worn. This can easily be done using a set of plastic ring sizers which have been split open with a thin saw blade.
2. Size customer's ring to the proper closed size, not the knuckle size. This is an important step and will insure that the curve of the top will be correct.
3. Find out, if you can, which way the customer wears the ring. Put the opening end of the trigger toward the thumb. It makes it easier to operate if worn this way.
4. Remove top of customer's ring, making sure that there will be enough room for the hinge mechanism on the Lockshank®.
5. Place this piece on a mandrel and mark the end points on the mandrel at the size the ring needs to be. Slide the Lockshank® onto the mandrel and mark it where the marks you just made are centered on the top section.
6. Cut and remove the top of the Lockshank®. The customer's ring top and the Lockshank® should fit together at the proper size you want to achieve.
7. Solder the top to the Lockshank®, file to blend, and finish.

Bending the cut Lockshank to match the curve of a skewed ring enables the goldsmith to install this product on rings that would otherwise be impossible to fit with an expandable shank.

Helpful Hints

• These shanks come only in whole sizes. If you require other than a whole size, order the size below what you need When installing, split the difference between the Lockshank® size and the desired size, and add equal amounts to either the top portion or the Lockshank®. Do this before cutting either piece. The adjustment to the curve will be easy to accomplish.
• If the MM width doesn't match with what is available, any of the sizes can be reduced enough to fit the existing ring by carefully filing away the sides. This is best done after attaching the Lockshank®. The goldsmith will never have to remove more than a half millimeter per side.
• The hinges have been assembled without solder, so the goldsmith can solder reasonably close to the hinge. Proper care must be taken not to freeze the hinge during installation. Permanent magic marker ink applied to the hinge will keep the solder from flowing into the mechanism.
• Subsequent small sizing changes in a previously-installed Lockshank® can be done most easily at the side where the original join was made. If necessary, an installed Lockshank® can be sized smaller by removing equal-sized pieces from the grooved and the trigger pieces. The locking pin will have to be removed and replaced where it locks properly. Obtaining the proper size before starting will reduce the need for this procedure.
• These shanks come with a rectangular cross-section. Because the mechanism is in the center, they can be filed to fit a rounded or comfort-fit ring shape. Wider sizes can be tapered slightly.

The original ring was wider on one side than the other. The shank was cut off, and a Lockshank® wide enough for the thin side was installed. Two tapering strips of gold were attached, returning the wide side to its original shape. The cleanup leaves the ring looking almost the same as the original.

Technical Information

• The locking pin fits snugly into the hole in the grooved part. It doesn't accidentally release, because the spring tension of the trigger piece holds it in place. The trigger is almost half the circumference of the ring, so the spring tension uses the entire length of the trigger to lock. There is hardly any stress to the overall piece because it only has to travel the height of the locking pin.
  If the trigger piece gets out of round and doesn't lock any more, it is easily returned to its proper shape with careful bending. This can be done by the user. When the trigger piece is placed in position without the grooved piece in place, it is easy to see whether the trigger is out of round. If it looks like a part of the entire circle, with space for the grooved piece under it, then it will work properly.
  
• The pieces were created on a computer and cast from metal molds. The architecture on all sizes is uniform. The thickness of the ring is 1.8mm, and the thickness of the trigger piece is 1.2mm. The hinge pins are 1/2 the thickness, allowing for even wear on both the pin and the hinge. The trigger piece is 1/2 the width of all sizes up to 5.5mm, and for the rest of the sizes, it is 1/3 the width. The trigger pieces were designed to stick up very slightly above the plane of the grooved piece at the very end, allowing for easy opening. Because the hinge pins are welded rather than soldered, the benchworker doesn't run the risk of cutting through the solder when it is necessary to file the Lockshank to fit the existing ring.