This maker was in business from 1832 until at least 1869. Samuel Blackwell Schenck (1806-1861) was one of the three members of the Woodworth planer patent syndicate. See the entry under William Woodworth for the whole sordid story.

Advertising coin from 1834. These coins turn up occasionally on eBay.

Samuel B. Schenck had a monopoly on New England, and he manufactured the machines for his territory. He also sold machines into the territory of Samuel Pitts, who did not manufacture machines.

After the Woodworth patent expired and the syndicate disbanded in 1856, Schenck continued to manufacture "for some time before business failure," according to the 1985 book, Planers, Matchers and Molders in America. Because Schenck, like the other monopoly manufacturer, John Gibson, did not improve his machine designs over the term of the monopoly, and because the monopolists were rather unpopular, sales likely plummeted after 1856. In 1869 and 1870, John B. Schenck received patents for a series of improvements to planers, matchers, and saws. This series of improvements ended with John B.'s death in 1870

This business operated as S. B. Schenck until his death in 1861, after which it operated as Schenck Machine Co. By 1869 it was operating as John B. Schenck & Sons. John Blackwell Schenck (Samuel B.'s younger brother) died the following year, at which time the "John B. Schenck & Sons" name disappeared. We have a single undated data point for a company named H. B. Schenck.

Information Sources

• From Chandler W. Jones' Planers, Matchers and Molders in America, which got much of its information on Schenck from Charles Tompkins' A History of the Planing Mill.
• Ads in 1866-1869 issues of Scientific American. An 1857 ad simply uses the name S. B. Schenck. An 1866 ad is for Schenck Machine Co.; Samuel B. was not listed among the company officers - John B. Schenck was the president, and T. J. B. Schenck was the treasurer. An 1867 ad lists John B. Schenck as the president of the company. An 1869 ad gives the company name as John B. Schenck & Son. An 1870 New York State directory lists the company as John B. Schenck & Sons. John B. died in August of that year.
• A genealogist correspondent, besides providing some of the other details given here, reports that John had three sons: Henry, William, and John, born 1843, 1845, and 1847, respectively.
• Here is the text of an 1857 ad from Scientific American:

  WOODWORTH PLANERS, STEAM ENGINES, &c.—Twenty-seven years’ experience enables me to furnish Woodworth Planers for surfacing one or both sides, planing and matching, rabbiting, beading,or for moldings or clapboards, in any variety of beautiful construction and great power. Ample evidence of the superiority of my machines will be furnished from parties that have other machines in the same mill. Every machine will be accompanied, if desired, with a written warrantee. As some parties have been supplied with machines of another make when they supposed they were getting mine, I would advise that purchasers should buy none unless my name is on in full. Matteawan steam engines, machinists’ tools, cotton and woolen, sash, blind and door machinery, leather banding, &c., furnished at the manufactory at Matteawan, N. Y., or at 62 Courtland street, N. Y. S. B. SCHENCK, Agent.

• Every Day But Sunday: The romantic age of New England industry, by Jennie Copeland, 1936, has the following.

  Samuel B. Schenck, who was making carpenters' planes in a small shop in South Foxboro, wished to have larger quarters and to be nearer the railroad. In Our Town [i.e., Mansfield, Mass.], a few rods from the railroad station and on the Rumford River, he found exactly the site and small shop he wanted. He didn't care about the small shop. It was there. He at once built a two-story shop. For ten years Loren Willis and his brother, Ichabod, had been making axles in the shop, but Schenck offered them a price that induced them to sell. For $4500, Mr. Schenck was able to buy the little shop, five and three quarter acrews of land, the privilege of the run-way, the privilege of flowage from October eleventh to April eleventh annually, and also an old sawmill.

  Immediately, Mr. Schenck began buying more real estate, and commenced building; first, he bought a house for himself and half an acre of land with a string attached attached (former owners reserved the right to dig for coal, or other minerals, but promised to make restitution, if they damaged any crops); next, he bought land all around him, put up buildings, constructed a mill dam and mill pond; soon, he had a two-story shop that was then considered large, several tenements for his help, and a store where his employees were expected to trade. Later, after the death of Solomon Pratt and the burning of the Pratt and Bates Cotton Factory in 1850, Mr. Schenck bought that property and thus controlled that water privilege beyond his own plant. This, however, he disposed of in four years to McMoran and Fulton for their knife works.

  It was, therefore, not long after his arrival in town that the new shop was built and in full operation, doing a twenty-thousand-dollar business and by far the largest concern here. He employed from thirty to fifty men. The company was called the Mansfield Machine Company. Samuel B. Schenck was the president and principal owner. The directors were listed as T. J. B. Schenck and John B. Schenck, one and the same person, we suspect, and in fact, a brother of Samuel, the president.

  Samuel Schenck took an interest in the town. At his own expense he built a road three quarters of a mile long, from the railroad station past his factory to the knife shop of Moran and Fulton. He gave thirteen lamps, including a chandelier, the whole costing one hundred dollars, to the Congregational Church, when the building was completely renovated in 1852. He gave his support to the Mansfield Academy, by sending his three children there.

  There is a story that Samuel Schenck had political aspirations. He wanted to represent Our Town in the legislature in 1854, so the tale runs, and John Rogers, the straw shop owner, also wanted to go. Mr. Rogers usually had things just about as he wanted them politically and he did this time. Schenck took his defeat so bitterly, so they say, that he moved his family and part of his business out of town.

  Whether or not the story is true nobody knows. Certain it is that at that time, less than ten years after coming here, he took up his residence at Fishkill, New York.

  The Mansfield Machine Company continued in business after Mr. Samuel Schenck's removal from town, but in a few years it fell on evil days. It had a hard time weathering the business crisis of 1854-57. Samuel Schenck took a personal mortgage of nine thousand dollars and there was already a small mortgage to Loren Willis that had never been paid. Six months after Mr. Schenck took the nine tousand-dollar mortgage, he gave an eleven thousand-dollar mortgage to an Attleboro man. Eventually, the mortgage was in the hands of the Wrentham bank. In 1864 the bank had to foreclose and at once disposed of the factory to the Murphy brothers, whose story was told in the last chapter.

  The Murphy brothers converted the factory to the manufacture of cutlery.