Looking for help identifying an unusual ratchet C-Clamp lock

Still working on the Stewart collection.  
eBay Items

We found this lock while listing his handcuffs and leg irons.  It weighs about 8 ounces and the inside circumference is about 7 1/2 inches (about wrist size).  25 locking stops control the pin closing in fine increments.  The markings are hard to make out "Universal Products", "San Francisco", "Pat"...

The question is "Does anyone know what this is?"

I think in days gone by that night clubs and better restaurants used these locks to secure their patrons overcoats and hats while dining and being entertained.

Correct. So, back when cars first came about, driving cars that didnt have a roof, tended to get cool, in the evenings. They had what they called "driving robes." But, when you got to where you were going, you didnt want to have to carry your driving robe, everywhere with you. If you left the robe in the car, it was likely to be stolen. The car makers started putting what looked like a towel bar on the back of the seat. You would hang your robe over the bar and secure it to the bar using a "robe lock." This was Defiance Universal Products own design for a robe lock. This picture shows how the bar would have looked, though this was an advertisement for the robe lock of another company.
-Richard Knip-

Thank you for the information.