John T. Parsons
Encyclopedia
John T. Parsons pioneered numerical control
for machine tools in the 1940s.
These developments were done in collaboration with his employee Frank L. Stulen
, who Parsons hired when he was head of the Rotary Wing Branch of the Propeller Lab at Wright-Patterson Air Force Base
, in April 1946. Together, they were the first to use computer
methods to solve machining problems, more in particular, the accurate interpolation of the curves describing helicopter
blades. In 1946, "computer" still meant a punched-card operated calculation machine. In 1948, Parsons' company, "Parsons Corporation" of Traverse City, Michigan
, was awarded a contract to make the innovative and challenging tapered wings for military aircraft; they won the contract because they developed the computer support to do the difficult three-dimensional interpolation for the complex shapes, as well as the 800 steps long production cycle for the wing manufacturing. IBM
was one of the subcontractors, as was MIT, which took care of the servomechanism
s. The latter lab boosted the developments of CNC machining in the following decades, by developing reliable servo control in 1952 and the APT
(Automatic Programmed Tool) programming language for CNC machines. It was only after the servos were also steered by computers that real "numerical control" was realised. The initial developments of Parsons and Stulen were only about the calculations, and not the control: the results of the calculations were given to human operators that turned the wheels on the machine tool to generate the desired tool paths.
Parsons, however, quickly saw the potential of connecting computers to the machine motors. On January 14th, 1958, he received a patent
for a Motor Controlled Apparatus for Positioning Machine Tool (patent number 2,820,187, filed on May 5th, 1952).
The initial developments of NC machines, however, had been so expensive, that Parsons was fired from his own company, because the funding of the MIT developments was too much for the company. Parsons was reinstated as president of the company, after royalties on the patent had generated significant amounts of money. (Bendix Corporation
was an initial license taker of the patent, in 1955, and eventually bought all the rights to it.)
In 1985, Parsons and Stulen received the National Medal of Technology
. In 1988 he received an honorary Doctor of Engineering degree from the University of Michigan
. In 1993, Parsons (but not Stulen) was inducted into the National Inventors Hall of Fame
for inventing numerical control.
On Wednesday April 19, 2007 John T. Parsons died at the Grand Traverse Pavilions. He was 93. He had a son, David Cameron Parsons.
Numerical control
Numerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...
for machine tools in the 1940s.
These developments were done in collaboration with his employee Frank L. Stulen
Frank L. Stulen
Frank L. Stulen invented numerical control of machine tools, together with his employer John T. Parsons, in the 1940s. Parsons received most of the credit, since he came up with most of the original ideas; However, Stulen was the one who turned these ideas into working machines.In 1985, Stulen and...
, who Parsons hired when he was head of the Rotary Wing Branch of the Propeller Lab at Wright-Patterson Air Force Base
Wright-Patterson Air Force Base
Wright-Patterson Air Force Base is a United States Air Force base in Greene and Montgomery counties in the state of Ohio. It includes both Wright and Patterson Fields, which were originally Wilbur Wright Field and Fairfield Aviation General Supply Depot. Patterson Field is located approximately...
, in April 1946. Together, they were the first to use computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
methods to solve machining problems, more in particular, the accurate interpolation of the curves describing helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...
blades. In 1946, "computer" still meant a punched-card operated calculation machine. In 1948, Parsons' company, "Parsons Corporation" of Traverse City, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
, was awarded a contract to make the innovative and challenging tapered wings for military aircraft; they won the contract because they developed the computer support to do the difficult three-dimensional interpolation for the complex shapes, as well as the 800 steps long production cycle for the wing manufacturing. IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
was one of the subcontractors, as was MIT, which took care of the servomechanism
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...
s. The latter lab boosted the developments of CNC machining in the following decades, by developing reliable servo control in 1952 and the APT
APT programming language
APT or Automatically Programmed Tool is a high-level computer programming language used to generate instructions for numerically controlled machine tools. Douglas T. Ross is considered by many to be the father of APT. APT is a language and system that makes numerically controlled manufacturing...
(Automatic Programmed Tool) programming language for CNC machines. It was only after the servos were also steered by computers that real "numerical control" was realised. The initial developments of Parsons and Stulen were only about the calculations, and not the control: the results of the calculations were given to human operators that turned the wheels on the machine tool to generate the desired tool paths.
Parsons, however, quickly saw the potential of connecting computers to the machine motors. On January 14th, 1958, he received a patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
for a Motor Controlled Apparatus for Positioning Machine Tool (patent number 2,820,187, filed on May 5th, 1952).
The initial developments of NC machines, however, had been so expensive, that Parsons was fired from his own company, because the funding of the MIT developments was too much for the company. Parsons was reinstated as president of the company, after royalties on the patent had generated significant amounts of money. (Bendix Corporation
Bendix Corporation
The Bendix Corporation was an American manufacturing and engineering company which during various times in its 60 year existence made brake systems, aeronautical hydraulics, avionics, aircraft and automobile fuel control systems, radios, televisions and computers, and which licensed its name for...
was an initial license taker of the patent, in 1955, and eventually bought all the rights to it.)
In 1985, Parsons and Stulen received the National Medal of Technology
National Medal of Technology
The National Medal of Technology and Innovation is an honor granted by the President of the United States to American inventors and innovators who have made significant contributions to the development of new and important technology...
. In 1988 he received an honorary Doctor of Engineering degree from the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
. In 1993, Parsons (but not Stulen) was inducted into the National Inventors Hall of Fame
National Inventors Hall of Fame
The National Inventors Hall of Fame is a not-for-profit organization dedicated to recognizing, honoring and encouraging invention and creativity through the administration of its programs. The Hall of Fame honors the men and women responsible for the great technological advances that make human,...
for inventing numerical control.
On Wednesday April 19, 2007 John T. Parsons died at the Grand Traverse Pavilions. He was 93. He had a son, David Cameron Parsons.