Who Patented Gas Absorbsion Refigeration?

We have friends from the states who own an island in Canada in Lake of the Woods. They have a 45 year old Servel gas absorption refrigerator which has been in their family that long. They use it in the cabin. They go up every summer for 3 months to live off the grid, then shut everything down and return to the states. In 45 years the fridge has never failed.

Dale