I know in the HES studio spot and color 575 line, the NEC required them to design it so that you had to use a tool to remove the lamp since the instrument does not have a safetyswitch to shut off the lamp if the lamp housing were opened during operation. Just a little info.
Note also the "locking" pin connectors in the lower right hand corner. Could it be that the figure8 springs were not captive and easily lost played a role in the lack of success of this connector? I think I may have one of these connectors (minus spring) somewhere. The single-pole connectors are today more commonly known as Mole-Pins or studio-pins, and still available from Mole Richardson.
I know in the HES studio spot and color 575 line, the NEC required them to design it so that ...
That page is from the 1957 catalog, but according to the website, a 100 amp connector such as that was offered from the 1913 catalog till at least 1965. It seems that a 60 amp version was also offered.
Interesting and unique connectors were offered as well. Check out the block two-fers and three-fers, designed to go on the end of a length of cable.
Or, the in-line tap.
I wonder if such a thing would be kosher these days? After all, LEX does offer a modern version of the idea in Edison. LEX E-String
I would like to note that while I link to the older catalog, most of these items can be found in various forms through all of the catalogs listed.
I wish someone would update that site with 70's-80's kliegl catalogs. It would fill the gap.