Friday, August 07, 2015

The History of the Wireless Pet Fence



The irony of a Wireless Dog fence is that it involves an installing all kinds of wires. Some brands call it an underground fence, radio fence or an invisible fence. Major brand names include Dogwatch, Havahart, Perimeter, Invisible, and others.  But at it's core it's just a loop antenna receiving a signal at a very cluttered
27 MHz. The "fence" is just a low power amplitude modulated (AM) radio signal broadcast from a thin wire buried along your property line. A small radio receiver worn by your dog in or on it's collar. When they breach the "fence' they receive an electrical shock and or hear a beep. In the 1990s some vendors marketed the idea of attaching them to children.


The history of the wireless fence goes back easily a century. Back in the mid-1930s aircraft used beacon systems sometimes called a "wireless fence" to navigate to their destinations. The idea was similar. A signal can be sent and received to convey position or navigation data. But the term "wireless fence" appears in agricultural magazines and even science fiction back to at least 1916.

There wasn't much in the way of prepackaged wireless-fence products until the 1970s. The first commercial system was invented, patented in Allentown, PA by Richard Peck in 1973. Peck patented his "fence" in U.S. Patent Number 3753421 entitled "Method and Apparatus for Controlling an Animal." It is referenced by an amazing 65 other patents as prior art. Peck in turn, lists more than 30 others as references including animal training devices that delivered a shock and RF proximity warning systems. No single part of the system was new, but combining them all for that sole purpose was.
He first sold the product via his company Sta-Put Sales Co. In 1976 Peck sold the rights to his "fence" to the Invisible Fence Co. which still sells the product today. The first dealership opened in 1982. they sold 17,000 systems in the first 10 years. The idea was Peck's, but he went to the University of Pennsylvania's School of Veterinary Medicine to test it's safety. And he relied upon Battelle Laboratories to help develop the a reliable receiving circuit. His patent expired in 1990 and Peck expired in 1997.

Peck lived long enough to see sales really pick up in the 1990s. In the 90s most wireless fence product ads began with the word "new." even though the technology was already half a century old, and the product had been on the shelves for at least 30 years. Dogwatch patented a FM based system in 1990. More here.