DEPOSITION CONCERNING INVENTOR OF DENTIST DRILL c 1893

Description

Offered here is a depostion document, c. 1893, 6 pages, signed in ink by Martha L. Green, wife of George F. Green. George F. Green (1830-1892) American inventor who made significant contributions to society throughout his life. In 1868 American George F. Green introduced a
pneumatic (air-driven) drill powered by a pedal bellows.
. Fellow American James B. Morrison patented a pedal bur drill in 1871. A further improvement of the Nasmyth-Merry design, the bur drill featured a flexible arm with a handpiece to hold the drill, a foot treadle, and pulleys. Each of these developments increased the speed at which the drill operated. In 1874, six years after he made his original contribution to drills, Green added electricity to the dental drill. Green's drill was powered by electromagnetic motors and worked well, but it was also heavy and expensive. Plug-in electric drills became available in 1908. By that time, most dental offices had electricity. In May of 1886, Mr. Green submitted US patent number 342,693 outlining his "photographic Shutter". This was the first documented pneumatic shutter invented. It operated on a wing shutter design that would actuate upon forcing air through a hand operated air pressure bulb. The patent outlines the goal of perfectly controlling the opening and closing through a piston-cylinder. He submitted an improvement in 1887 with US patent 362,111. Mr. Green filed a patent for his electric railway in 1879 defining one side of the track to be a positive conductor of the source of energy and the other the negative, such that a motor carried on the car can be suppled with electricity. The patent was initially rejected by the patent office. However, Mr. Green took his case to the supreme court and the court overruled the Patent office. A second patent was filed in May of 1886 which described a method of motor control. It was not until after his death that the patent office issued his patents. Folds o/w very good condition. Rare! VG