| Gauge Blocks |
Article Index for Gauge |
Website Links For Gauge |
Information AboutGauge Blocks |
| CATEGORIES ABOUT GAUGE BLOCKS | |
| dimensional instruments | |
| metalworking measuring instruments | |
|
They are available in various grades depending on their intended use. {Link without Title} .
More recent grade designations include (U.S. Federal Specification GGG-G-15C):
and ANSI/ASME B89.1.9M, which defines both absolute deviations from nominal dimensions and parallelism limits as criteria for grade determination. Generally, grades are equivalent to former U.S. Federal grades as follows:
The ANSI/ASME standard follows a similar philosophy as set forth in ISO 3650 . See the NIST reference below for more detailed information on tolerances for each grade and block size. HISTORY The gauge block set, also known as "Jo Blocks", was developed by the Swedish inventor Carl Edvard Johansson . Johansson was employed 1888 as an armourer inspector by the state arsenal Carl Gustaf Stad's Rifle Factory in the town of Eskilstuna, Sweden. He was concerned with the expensive tools for measuring parts for the Remington rifles, then in production. When Sweden adopted the Mauser carbine in 1894 Johansson was very excited over the chance to study Mauser's methods of measuring. However, a visit to the Mauser factory in Oberndorf turned out to be a disappointment. On the train home he started thinking about the problem and came up with the idea of a set of blocks that could be combined to make up any measure. Back home Johansson converted his wife's sewing machine (a Singer machine) to a grinding and lapping machine, as the grinding machines at the Rifle factory were not good enough and he preferred to carry out this precision work at home. His wife, Margareta helped him a lot with the grinding beside the household works. Once Johansson had demonstrated his set at Carl Gustaf his employer provided time and resources for him to develop the idea. Johansson was granted his first Swedish patent on the 2nd may 1901, SE patent No. 17017 called "Gauge Block Sets for Precision Measurement". Johansson formed the Swedish company CE Johansson AB the 16th of march 1917 also known as 'CEJ'. Johansson spend many years in America. During his life he crossed the Atlantic 22 times. The first CEJ gauge block set in America was sold to Henry Martin Leland at Cadillac Automobile Co. around 1908. The first manufacturing plant in America for his gauge block sets was established in Poughkeepsie, Dutchess County, NY state in 1919. Economy did not turn out so well for the company so in 1923 he writes a letter to Henry Ford at the Ford Motor Company, where he proposed a cooperation in order to save his company. Henry Ford became interested and the 18th of november, 1923 he began working for Henry Ford in Dearborn, Michigan. He stayed for 12 years at Ford. At the age of 72, in 1936, he felt it was time to retire and go back to Sweden. He was awarded the large gold medal of The Royal Swedish Academy of Engineering Science, posthumously in 1943, shorly after his death. SOURCE "C.E. Johansson-The Master of Measurement" by Torsten K.W. Althin at the request of AB C.E. Johansson, published by the company in 1948. GAUGE BLOCKS Shown at right is an image of a metric gauge block set, close examination of the set will show that the set consists of a range of varying size blocks, along with two wear blocks. In use the blocks are removed from the set, cleaned of their protective coating (petroleum jelly or oil) and ''wrung together'' to form a stack of the required dimension, with the minimum number of blocks. The wear pieces are included at each end of the stack whenever possible as they provide protection against damage to the lapped faces of the main pieces. After use the blocks are reoiled or greased to protect their faces from corrosion. Wringing is the process of sliding the two blocks together so that their faces lightly bond. When combined with a very light film of oil, this action excludes any air from the ''gap'' between the two blocks. The alignment of the ultra smooth surfaces in this manner permits ''Molecular attraction'' to occur between the blocks and forms a very strong bond between the blocks along with no discernible alteration to the stacks overall dimensions. Accessory set The pictured accessories provides a set of holders and tools to extend the usefulness of the gauge block set. They provide a means of securely clamping large ''stacks'' together along with reference points and scribers. GAUGE PINS Similar to gauge blocks, these are precision ground cylindrical bars for use in Go-NoGo Gauge s or similar applications. GAUGE ROLLERS AND BALLS These are supplied as sets of individual rollers or balls as used in Roller Or Ball Bearings REFERENCES |
|
|