These are for niche needs. For most applications neither is necessary. If needed and space is constrained the single pin variant allows additional connectors to be packed together on a single PCB. The dual pin option doesn’t, it takes up space that could be used for additional connectors.
It looks exactly like what I imagined by screw-lock USB connector, but the single pin seems to be a really inspired design somebody had and made the entire committee angry for some reason.
The single pin only resists force. Two pins resist torques being applied to the usb connector. The single pin does resist torque but it uses the connector potentially damaging the PCB.
But why not make a dual screw design by adding one more screw to the bottom of the current single screw one? Would be more compact and allow them to be more cross compatible.
PCB are designed with things on top of them. Typically they are mounted with the bottom of the PCB at the bottom of a case. So following normal conventions there wouldn’t be a place for the bottom screw to go into something. Unless you used a bespoke case. It’s much easier to have the two screw design place the screws above the PCB.
It may seem like a minor change, but it costs substantial more in design time and effort. New folded steel cases and injection moulded cases would have to be developed. Designers would use a different port, or worse deploy their own two horizontal screw design. There would then be several two screw designs (metric/imperial/very close/very far etc).
Anyone with the niche need of the two screw vertical design would likely rotate the whole connector or use a flex cable to join the connector to the main board.
USB-C has official specifications for a screw lock connector
Nice
Why are technical drawings so much cooler?
Fun fact: if you design in fusion 360, you can make technical drawings quite easily with only a couple clicks.
Fun fact: FreeCAD is better
I wish
Because engieneering is so much cooler.
Why two different and incompatible options?
Or, more generally, why can’t I ever read some USB spec and get out with less questions than I had in the beginning?
Probably for the same reason why they decided to rename USB 3.0.
I guess they had a liquor cabinet in the room where they held their meeting
Because for some reason, the USBIF has been hit over and over again with the stupid stick ever since USB2 came out.
These are for niche needs. For most applications neither is necessary. If needed and space is constrained the single pin variant allows additional connectors to be packed together on a single PCB. The dual pin option doesn’t, it takes up space that could be used for additional connectors.
I se no advantage at all for the dual pin design.
It looks exactly like what I imagined by screw-lock USB connector, but the single pin seems to be a really inspired design somebody had and made the entire committee angry for some reason.
The single pin only resists force. Two pins resist torques being applied to the usb connector. The single pin does resist torque but it uses the connector potentially damaging the PCB.
Short version: looks good, functions bad
But why not make a dual screw design by adding one more screw to the bottom of the current single screw one? Would be more compact and allow them to be more cross compatible.
PCB are designed with things on top of them. Typically they are mounted with the bottom of the PCB at the bottom of a case. So following normal conventions there wouldn’t be a place for the bottom screw to go into something. Unless you used a bespoke case. It’s much easier to have the two screw design place the screws above the PCB.
It may seem like a minor change, but it costs substantial more in design time and effort. New folded steel cases and injection moulded cases would have to be developed. Designers would use a different port, or worse deploy their own two horizontal screw design. There would then be several two screw designs (metric/imperial/very close/very far etc).
Anyone with the niche need of the two screw vertical design would likely rotate the whole connector or use a flex cable to join the connector to the main board.
Because USB is pretty much neither universal or standardized, just the same shape and somewhat compatible
The single screw version looks wrong somehow.
I wish things actually used this, it looks really stable.
Well, you can buy them: https://www.coolgear.com/product/usb31-type-c-to-c-dual-screw-lock-cable
That’s cool, but I wouldn’t have anything to attach it to. It would be great if my laptop had those ports though.
You usually do not want connectors to be too stable.
The fact that it unplugs before any part breaking or pushing your devices away is almost always a feature, not a bug.