Goldman continued to make modifications to his original design, but advice from his trusted business partners Fred Taylor, a grocery store owner, and George O'Donnell, a grocery store refrigeration salesman, and the incorporation of Watson's swinging door yielded the familiar nesting cart that we see today (albeit the original telescope cart had two baskets rather than one). Goldman patented a similar version of the cart which he called the "Nest-Kart" in 1948, over one year after Watson filed for his patent. The Nest-Kart incorporated the same nesting mechanism present on the shopping carts designed by Watson, and an interference investigation was ordered by Telescope Carts, Inc. alleging infringement of the patent in 1948. After a protracted legal battle, Goldman ultimately recognized Watson's invention and paid one dollar in damages for counterfeit, in exchange for which Watson granted Goldman an exclusive operating license (apart from the three licenses that had already been granted). In 1909, Bessie DeCamp invented a seat belt for chairs, go-carts or carriages. This was well before shopping carts with child seating areas were invented. Goldman introduced a child seating area on shopping carts in 1947. For whatever reason, it wasn't until 1967 that seat belts for shopping carts were introduced by David Allen. It was high tech for the time, because it was a retractable seat belt. In 1946, Orla Watson devised a system for a telescoping (i.e., "nesting") shopping cart which did not require assembly or disassembly of its parts before and after use like Goldman's cart; Goldman's design up until this point required that the cart be unfolded much like a folding chair. This cart could be fitted into another cart for compact storage via a swinging one-way rear door. The swinging rear door formed the basis of the patent claim, and was a major innovation in the evolution of the modern shopping cart. Watson applied for a patent on his shopping cart invention in 1946, but Goldman contested it and filed an application for a similar patent with the swinging door feature on a shopping cart with only one basket in 1948 which Goldman named the "Nest-Kart". After considerable litigation and allegations of patent infringement, Goldman relinquished his rights to the patent in 1949 to Watson and his company, Telescope Carts, Inc. realizing that the swinging rear door feature was the key to Watson's patent. Watson was awarded patent #2,479,530 on August 16, 1949. In exchange, Goldman was granted an exclusive licensing right in addition to the three other licenses previously granted; Telescope Carts, Inc. continued to receive royalties for each cart produced by Goldman's company that incorporated the "nesting" design.