does anbody remember this "Heater" (found the patent)

some oil filled get pretty warm to fire danger smoldering levels
especially the smaller ones that are full 1500w

at one time or another i've had every type
we have an 400-800w quartz radiant reflective for these occasions when shore power is available, it does what i expect
but i really would like to find one of the Heatech type, older or newer, its the way it works that i like, the whole concept was innovative