Looking for keyboard slides with positive lockouts
I've been searching for this hardware for some time now and have not scored. I have two computer tables with under-hanging keyboard trays. You pull out to use and push in to hide. However, these tables did not come with any lockout device so when you use the keyboard vigorously as in gaming, the tray it sits on slides or rolls away from your hands. I bought a set of supposedly locking tray slides from Amazon only to find they have just a friction hold point not an actual detent so, again, if you push just a bit while using, they slide or roll away from your hands. What I want is cup-like divot in the slides wherein the rollers on the keyboard tray actually drop into the divot thus creating a positive lockout. I used to have a computer desk with such a keyboard mechanism where you actually lifted the tray up a bit so the rollers would drop into said divot. Same for retracting. Lift up a bit and push the tray back in. Some cabinet drawer slides work this way but they are too short to accommodate sliding a keyboard and mouse under the main table top when not in use. Has anyone seen this type of keyboard slide for sale anywhere? Thx!