Frank Zamboni Spent Years Building a Machine So His Ice Rink Didn't Need a Crew of Men With Scrapers

US2642679 was filed by Frank J. Zamboni on May 16, 1949, and granted in 1953. The Patent Office title is Ice Rink Resurfacing Machine. Zamboni is now a trademark so familiar that most people use it as the generic name for the machine, which the company has spent years politely correcting.

The rink

Frank Zamboni grew up on a farm in Idaho and moved to Southern California, where he and his brother ran an electrical business and then a plant that made block ice, used to keep produce cold in shipment. That second business gave him a detailed practical understanding of how water freezes.

As electric refrigeration made block ice less necessary, the brothers looked for another use for what they knew. In 1940 they opened Paramount Iceland, a large skating rink in Paramount, California.

Running a rink turned out to involve a constant, expensive chore.

The job being replaced

Skating destroys an ice surface quickly. Blades cut grooves, gouge chips, and leave a rough layer of snow. After a session the ice has to be restored, and before Zamboni's machine that was done by hand.

The usual process took a small crew. A tractor dragged a scraper over the ice to shave off the rough top layer. Workers shoveled up the shavings. Water was sprayed over the surface, squeegeed to clear away debris, and then everyone waited for the new layer to freeze. The whole procedure took more than an hour, and the rink was not earning money while it happened.

Zamboni wanted one machine, operated by one person, that did all of it at once.

Seven years of prototypes

He started working on it in the early 1940s, and it took years to get right. The first several versions did not work. He built the machine that finally succeeded, the Model A, largely from war-surplus parts, including components taken from a Jeep. It was finished in 1949, the same year he filed the patent.

The machine does the entire resurfacing sequence in a single pass as it drives across the rink.

A sharp horizontal blade at the rear shaves a thin layer off the top of the ice. A screw conveyor gathers the shavings and carries them up into a snow tank on the machine. Water is sprayed to wash out the grooves, and the dirty water is picked back up. Finally a cloth spreader lays down a thin, even film of clean water that freezes into a smooth new surface.

Why the water is warm

This is the part of the process that surprises people, and it is where Zamboni's background in making ice shows.

The water laid down at the end is warm, not cold. Cold water sitting on top of ice freezes as a separate layer that does not bond well to the surface below, and it traps small air bubbles that make the ice cloudy and weaker. Warm water melts the very top of the existing ice slightly, so the new layer fuses with the old one instead of sitting on it. Warm water also holds less dissolved air, so the fresh layer freezes clearer and harder.

It seems like the wrong choice for making ice. It is the reason the surface ends up smooth.

Sonja Henie

The machine could have stayed a clever local solution. What changed that was Sonja Henie, the Norwegian Olympic figure skating champion and film star, who practiced at Paramount Iceland. She saw the machine at work and ordered one for her touring ice show.

A show that traveled from city to city, skating on rinks of varying quality, had an obvious use for a machine that could produce a good surface quickly anywhere. Word spread through the skating world from there, and the company went into regular production.

Frank Zamboni died in 1988. The company is still run by his family, and the machines still follow the sequence in his patent: shave, collect, wash, and lay down warm water.

See the original

The full text and figures of US2642679 are on patents.us.