Samsonite Focus Attache case/bag gravity latch/lock replacement part

thingiverse

The patented "right-side-up feature" of my vintage Samsonite Focus 4" attache case, a 27-year-old piece of luggage, finally gave in to gravity. The lock mechanism, known as the "gravity lock," broke, but fortunately, everything else was still functioning properly. After contacting the Singapore distributor, I discovered that they only had replacement parts for the entire lock mechanism, not just the broken component. I was left with no choice but to replace the entire locking system. When it was working correctly, my Samsonite Focus attache case could perform several impressive feats: 1. It would open when placed right-side up. 2. It would open vertically to access the portfolio compartment located at the back. 3. It prevented the lock from opening when the case was upside down. You can view the patent for this innovative design on patents.google.com, specifically US3828899. The plastic latch in question is item 28-32 of the patent, and unfortunately, mine has broken. To perform activity 2, the latch must be precisely balanced; item 29 must weigh exactly the same as items 28, 31, and 32 so that it releases the catch when the case is vertical. In my initial attempt to repair the latch, I focused on reinforcing the high-stress areas. While this allowed me to achieve activities 1 and 3, it failed to enable activity 2. The case remained locked, and I was left with a puzzle to solve. After an extensive trial-and-error process involving the gradual removal of areas from the latch, I finally achieved the required balance. I measured and redrew the latch to ensure its precision. Now that I understand why Samsonite didn't reinforce the high-stress area of the hook, it's clear that such a move would have thrown off the balance and rendered the case unable to open vertically. However, with modern 3D printing technology, we can now create replacement parts that will extend the lifespan of our vintage Samsonite Focus attache cases. It appears that newer versions of this design no longer support activity 2, making our vintage models even more desirable. To assist others in replicating my repair, I've included the 3mf files used to shape the latch with Microsoft 3D builder and the "shape tools" employed during the process. Before exporting these files as STLs for printing, please remove all "shape tools" and merge the parts together.