John T. Wilkin was a draftsman and designer for P. H. & F. M. Roots of Connersville, Indiana, makers of rotary-impeller blowers of novel design.

The Roots Blower. From patent 30,157, granted in 1860 to Philander H. Roots.

Wilkin, recognizing that the shape of the impellers in the Roots blower was compromised for ease of manufacturing, calculated the optimal impeller shape which is the shape traced by a point on the perimeter of one circle as it rolls around the circumference of another circle. Wilkin then designed a planer to manufacture such a shape. It is not known whether he tried to convince the Roots management to pursue his improved impeller design, but however those events unfolded, Wilkin left Roots at the beginning of 1893 and formed a new business to manufacture blowers, pumps and compressors based on his improved impeller. He contracted with machine-tool manufacturer Pedrick & Ayer of Philadelphia to build his impeller planer design and convinced W. W. Wainwright, foreman of Roots' machine shop, to join his new venture. In March the Connersville Blower Co. was formally organized, and in May the new business was announced to the trade press. Their first product was a positive-pressure blower that was made available in about August 1893.

The Wilkin blower. From patent 905,967, granted in 1908 to John T. Wilkin

The company's product lineup soon expanded to include gas exhausters, pumps, air motors, and compressors, and customers found them to be highly efficient and exceptionally powerful compared to similarly sized products from the Roots company. It appears that although Connersville Blower charged a premium for their products, sales grew quickly.

By 1931 P. H. & F. M. Roots had become the Roots Blower Co. In that year the Roots Blower Co. and Connersville Blower Co. were acquired by the International Derrick and Equipment Co., and merged them to create the Roots-Connersville Blower Co. In 1944 Roots became a product brand of Dresser Industries. In 2015 the Roots company was acquired by Colfax Corporation, and is now part of UK based engineering company Howden. [9] The Roots product line still includes a range of blowers.

Information Sources

• 1893-01-26 American Machinist.

  Mr. John T. Wilkin, who has been with the Root Co., of Connersville, Ind., for some years as draftsman and designer, and Mr. W. W. Wainwright, who has been for twenty-one years in the machine shop of the same establishment, latterly as foreman, have resigned their positions, and have organized a company, to be known as the Wilkin Mfg. Co., which will manufacture an improved force blower, the revolvers or impellers of which will be constructed on cycloidal curves. This blower and some special machine which will be used in its manufacture (some of which are being built at the establishment of Pedrick & Ayer, of Philadelphia), are the inventions of the gentlemen named, and it is expected that the new blower will be highly efficient.

• 1893-05-04 American Machinist, page 10.

  The Connersville Blower Co. of Connersville, Ind., has just been organized for the purpose of manufacturing rotary positive pressure blowers, gas exhausters, pumps, motors, etc., the internal working parts of which will consist of two impellers planed accurately on epicycloidal lines. This end will be reached by means of a planer invented by Mr. John T. Wilkin, the engineer of the company, and which will be described in one of the coming issues of the American Machinist. The company's capital will be $75,000, $65,000 of which has been subscribed. Shops are already under way, and the company intends to contract for a power plant, milling machines, lathes, planers, cylinder boring machines, shafting, belting, etc., in fact everything needed in a complete equipment.

• 1893-06-29 American Machinist, page 14, text ad

  This space has been engaged by The Connersville Blower Co., Connersville, Indiana, which will soon be on the market with a full line of Improved Rotary Positive Pressure Blowers, Gas Exhausters, Pumps, Motors, Etc., The internal operating parts of which will consist of two impellers planed accurately on epicycloidal lines. Address "Edgewood," Connersville, Ind.

• 1893-07-27 American Machinist page 6-7 has an illustrated article on the planing machine developed by John T. Wilkin for making epicycloidal impellers; see the "Publications" tab, above, for a copy of the article.
• 1894 Annual Reports of the Officers of State of the State of Indiana, Part 1, page 98 in a listing of "Articles of Association": "Connersville Blower Company—Articles of Incorporation / (filed) March 22, 1893".
• 1893-07-10 American Gas Light Journal, page 51, has a 1/3 page text ad from this firm for their Cycloidal Exhauster.
• October 1893 Technology Quarterly, page 205, in a report on exhibitors at the Columbian Exposition: "...A positive pressure blower, marked No. 4, made by the Connersville Company, Connersville, Indiana, which resembles the well-known Root blower, closes the list."
• 1893-11-02 The Iron Age, page 796, in "World's Fair Notes".

  The Connersville Blower Company of Connersville, Ind., exhibit in the Mines Building one of their cycloidal blowers, the invention of their engineer, John T. Wilkin. This blower is driven by a direct engine, and develops a positive pressure of very great force for the size of the machine shown. It is a rotary blower, of which the internal operating parts consist of two impellers shaped accurately on cycloidal lines. The box in which they are inclosed is internally in the form of an ellipse. The cycloidal impellers perfectly fit in the ends of the ellipse and in the corresponding parts of each other, so that there is no leakage of air but a positive pressure forward of the full supply entering the chamber. Gas exhausters, pumps, motors, &c., are to be built on this principle.

• 1894-01-01 American Gas Light Journal, page 14, lists the Connersville Blower Co. as a maker of exhausters.
• October 1896 Iron Molders' Journal mentions the Connersville Blower Co. in passing, while describing the lack of work in Connersville.
• August 1897 The Foundry, outside cover, is a full-page ad for the "Cycloidal Positive Pressure Blower" from Connersville Blower Co.
• Wikipedia page on Roots Blower Co.