The Wheelabrator: Minich's abrasive-throwing machine, patented from Mishawaka

1932–1939 · THE AIRLESS BLAST WHEEL, AND A PRIORITY QUESTION PRINTED WHOLE

The patent: The twentieth century's one indisputable Mishawaka patent of the first rank belongs to the foundry-equipment works on the city's east side, and its face is a Mishawaka document. Letters Patent No. 2,077,637, "Abrasive Throwing Machine," was filed 26 May 1934 and granted 20 April 1937 to "Verne E. Minich, Mishawaka, Ind., assignor to The American Foundry Equipment Company, Mishawaka, Ind." The specification describes the machine the industry came to call the Wheelabrator: a wheel or rotor carrying a plurality of throwing blades extending from its periphery inward short of the axis, fed abrasive at its center, and flinging the shot or grit off the blade tips at blasting velocity, with an adjustable control member to direct the stream — cleaning a casting in seconds, by centrifugal force alone, with no compressed air, where sandblasting took minutes. The patent family runs on in the files: the same grant reissued as Reissue No. 20,538 on 19 October 1937, and a divisional application maturing as No. 2,170,832 on 29 August 1939 — by then the inventor's residence on the patent faces had changed to Scarsdale, New York, the founder having left the city his machine named; the 1934 filing, the one that counts, is Mishawaka's. Minich was the company's founder — the man who had begun in 1908 leasing and selling a mechanical sand-cutting device to foundries — and the machine was his company's answer to the foundry's oldest bottleneck, made in the works the Businesses section carries: manufacturing consolidated at the eighty-three-acre Mishawaka site on 1 January 1926, the Wheelabrator introduced in 1933 on the company historian's account, and Mishawaka still the company's principal plant and world headquarters a generation later.

The priority question: How the machine is claimed matters, and the carriers divide in a way this section prints rather than resolves. The History Museum's account of the company calls the wheelabrator "the first successful airless blast cleaning method," developed during the Depression; the company's own historian, Tony Harris, writing in 1964, dates the introduction of "the first practical airless blast-cleaning machine" to 1933. Against those, the Auburn University case study of the company — a management study, careful on other points — places the development in Cleveland, Ohio, in 1932, and dates the company's move to Mishawaka to 1936. That chronology cannot stand with the patent's face, which has Minich residing in Mishawaka and assigning to the Mishawaka corporation in May 1934, nor with the company's own record of the 1926 consolidation and its January 1927 assembly-floor photograph; the Businesses section of this history has already weighed the study's move date and found for the company's. What survives the conflict is the documented core, and it is enough: the foundational patent of airless blast cleaning was filed from Mishawaka by the firm's founder in 1934, the machines were built here for half a century, and the process name the whole world uses for the method is the trade name this city's works coined for it. Whether the first experimental wheel turned in Cleveland in 1932 or in Mishawaka in 1933 is a question the settling sources — the company's engineering records of 1932–34 — have not answered in the record reached, and it is carried as an open question in this section's note rather than decided here.

Sources:

1. United States Patent Office, Letters Patent No. 2,077,637, "Abrasive Throwing Machine," filed 26 May 1934, patented 20 April 1937 — the patent document itself, via the Patent Office images: Verne E. Minich of Mishawaka, Indiana, assignor to The American Foundry Equipment Company, Mishawaka, Indiana; the bladed-wheel and control-member mechanism as the specification describes it.
2. Reissue No. 20,538 (19 October 1937) and U.S. Patent No. 2,170,832 (29 August 1939), the documents themselves, via the Patent Office images — the reissue and the divisional of the 1934 application, the inventor's residence by then Scarsdale, New York, the assignee still the Mishawaka company.
3. Tony Harris, "Wheelabrator History" (the company's history, 1 June 1964), as carried in the Businesses section — Minich's 1908 sand-cutting start; the 1926 Mishawaka consolidation; the first practical airless blast machine introduced in 1933.
4. The History Museum, South Bend, "Wheelabrator/Frye/American Foundry Equipment" — the wheelabrator as "the first successful airless blast cleaning method," developed during the Depression.
5. M. V. Uzumeri and J. T. Black, "Wheelabrator: A Case Study of Variation in Manufacturing Management" (Auburn University, January 1995) — the development placed in Cleveland in 1932 and the Mishawaka move dated 1936, printed as the conflict they are against the patent's face and the company's own record.