Furniture Locks
Furniture locks to keep sectional couches from sliding apart. A metal plate, to slip over pins on each section or clamp into place, would do it.
By W.H.Tapscott, Port Arthur, Texas.
January 1960
I wasn’t able to find anything representing this idea, however, on Amazon you can purchase a standard security steel cable for protecting furniture that you could be stolen by someone. (affiliate link)