The story
Asphalt paver
On November 15, 1930, in Aurora, Illinois, Harry Barber made a sketch of a new machine that became the asphalt paver. Harry asked patent attorney W.R. Chambers to examine this new machine. The patent was filed on August 20, 1932 with a publication date on December 22, 1936. This eventually became the beginning of the development of the modern asphalt paver. Today there is an entire industry that has been developed from this invention. The machine mixed and placed asphalt in a single operation. This was first exhibited at the 1931 Road Show in St. Louis. Barber realized that the mixing and placing operations needed to be separated, and the mixing section became the line of Barber Greene asphalt plants and the placing section became the Barber Greene paver line.
The early pavers used screw conveyors to distribute the mix in front of a screed that tamped the mix. This process meant that the asphalt was suitable for coarse-graded mixes. Dense-graded mixes that were common on city streets the machine experienced problems including surface imperfections. In 1933, Barber's son Ashley joined the company and in the same year the independent floating screed was developed. This screed, along with the tamper bar that permitted uniform material density of the finished surface were the two key features that made the machine successful. Early pavers had a hopper which material was dumped into and spread by an auger. The floating screed was supported by runners that traveled on the prepared base material.
On April 10, 1936, the U.S. Patent Office issued the initial patent number 2,138,828 "Machine for and process of laying roads", and on December 6, 1938, this patent was granted. By 1934, production had started on the model 79 paver which featured a feeder conveyor to move the material to the auger. In 1936, the 879 model was introduced. By 1940, this machine was upgraded to the 879-A Model. This machine was the standard asphalt paver around the world until the mid-1950s. These basic features that were introduced by Barber Greene have been incorporated into most asphalt pavers in use today (1987).
Company
Other Barber Greene firsts include:
First synchronized tampers (1945)
First paver on rubber crawlers (1958)
First hydraulic paver (1959)
First automatic screed control (1960)
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First hydrostatic paver (1970)
Barber-Greene products were licensed internationally under a number subsidiaries:
Barber-Greene Americas
Barber-Greene Canada
Barber-Greene Olding (England)
Barber-Greene Overseas
Barber-Greene also made a successful line of trenching machines, asphalt batch plants, asphalt drum mixing plants, and road recyclers called Dynaplanes.
From Wikipedia’s article on Barber-Greene, shared under CC BY-SA 4.0.4