Puzzle locks can be grouped in different categories, whether they're Trick Locks, sequential movement (n-ary), or simply having a unique mechanism that requires several moves, but not particularly n-ary. The Sliding Lock by Jean Claude Constantin falls into the last category of unique designs, with a mixture of sliding piece and (partially) hidden mechanism.

Constantin has designed quite a few different puzzle locks over the past years. Some of his best puzzle lock designs are actually in the n-ary category, like the Maze Lock or the Lock 250, usually requiring hundreds of moves to be opened. The sliding Lock, fortunately for the less courageous puzzlers, only needs about a dozen moves, but it doesn't mean it it'll be easy. I can guarantee it'll be less frustrating, though.

The puzzle has a nice feel to it. It's not too big nor too small, measuring 12.5cm x 8.3cm (4.9" x 3.3"), and I like its overall shape, reminiscent of an electric guitar's body. It's made of laser-cut wood, thus feeling very light in your hands, and the mechanism is comprised of three metal pegs that have the ability of sliding across the maze-like path. There's a fourth sliding piece, without a metal peg, having instead a small ball-bearing in the middle. The idea is to create a path with these four pieces so that you can lift the shackle. There are markings on the wood indicating where at least two of the pieces should be in its starting position. When you get to open the lock, you must try to close it again and return the pieces to their original configuration.

The puzzle didn't take me long to solve. I reckon it took less than 10 minutes, and most of that time was trying to figure out how to create a space for the bottom right peg to be moved and release the shackle. Once I discovered the correct move it was even easier to put the pieces back.

Closing Comments:

In the end, I didn't find the Sliding Lock very challenging, but I really liked its mechanism and enjoyed the solving process. The design could easily be adapted to a more challenging puzzle. Here's hoping for a Sliding Lock 2.0. If you like puzzle locks this is definitely a must-have.

Availability: You can find Constantin's Sliding Lock at Sloyd for just €14.90.

Links:

Jean Claude Constantin - Official Website

Jean Claude Constantin at Puzzle Place