Schick Adjustable Injector Question

In my still-to-be-tried lineup I have two Schick Adjustables, which I picked up for not very much. Similar to this one. I see how the adjustment knob works, moving the position of the safety bar. What seems odd is that, although the default position of the safety bar changes, it doesn't lock into place. I can move it by pushing against it with my thumb. I tried running the razor over my face without a blade, and it doesn't seem like the safety bar would move during shaving, but I wonder if this is safe. Do I have two adjustables with the same defect, or is it supposed to be this way? I did put a blade in one, and it sits tightly in the razor, it's just the safety bar that can still move.

Mine all work that way - the safety bar moves with thumb pressure but wouldn't on the face due to the two side pieces (either side of the safety bar) that are fixed in place. Besides, the only direction of movement is to the lesser exposure so there's no danger.

Thanks garyg. Just wanted to be sure. I'll probably try one of these next in my rotation then, after I use up my current SE blade.