Links TO THE PAST: Restorers face challenge in quest for replacements of early detachable-link chain.
During the early days of the 20th century, the development of mechanized farming was exploding. Many functions were combined, and traditional "horsepower" was replaced by engines. Farmers also began to expect higher degrees of reliability from the newfangled machines. Day upon day of forced downtime was not an option. Answers were needed - and fast.
One critical solution was developed by William D. Ewart, who won a patent for a chain design offering both ease of use and fast repairs. Utilizing individual flat, malleable iron, detachable links, Ewart's chain provided flexible power transmission.
Some pieces of equipment required a simple conveyor system to enhance the process. Such systems employed a series of links called "hook chain." Wide individual wire links were hooked together to form a conveying system. Configured in a continuous belt, they could also be sprocket-driven.
Launch of Link Belt Co.
Detachable-link, malleable iron chain (also known as "flat chain") was created by William D. Ewart in 1874, and is covered by patent No. 188,113. Ewart, a farm implement dealer in Belle Plaine, Iowa, went on to launch Link Belt Co. in 1880. Eventually he relocated to Chicago, where he established Ewart Mfg. Co.
Ewart conceived the idea of a square detachable chain belt system for use in harvester equipment, an innovation for which he obtained a patent. This flat chain (also known early on as an Ewart chain) found many applications in the textile, sugar, grain and light coal industries, as well as in power transmission.
Attachment links intermingled with standard links made use of the chain possible in conveyors and elevators. Use of this chain waned as roller chains became commonly available in the 1920s and '30s. It is not clear when manufacture of malleable iron chain ceased, but inventories have long been depleted.
An 1880s-vintage advertisement touted the virtues of this revolutionary chain design: "The Ewart chain still has an enormous sale, on account of its great convenience and its comparatively low cost. It is a singularly ingenious form of chain, chosen not for its appearance but for its general utility. It is in fact the simplest of all chain types, and has the great merit of being very quickly detached or uncoupled. Thus it is easy to shorten or to lengthen such a chain at pleasure by removing or adding sufficient links to give the required length."
The advertisement also mentions enhanced capabilities: "The subject of attachments is a very important one in connection with conveyor chains. It is practicable to cast special or attachment links of almost any form on an Ewart chain; thus facilitating the fixing to the chain of elevator buckets, slats and other forms of carriers. In the course of time, a great variety of attachment links have been designed and standardized. These are now obtainable with the same facility as plain links from manufacturers' stocks."
Detachable-link chain was originally cast in malleable iron. Unfortunately for restorers, the malleable iron versions of this chain have not been manufactured for many years, perhaps not since the 1950s.
On some rare occasions, a slightly more modern version of punched steel detachable link chain might be substituted. But even those punched steel chains are extremely hard to come by. Today, most sizes are no longer available. While on occasion, a substitution might yield an acceptable mechanical solution, it does not contribute to an authentic restoration. Supplies of this steel chain are also very limited and most sizes of the steel chain are no longer manufactured.
Hook chain still in use
Hook chain provides an altogether different type of power transmission. It was used as cob rakes on several two-hole upright corn shellers such as the John Deere Model 2 and 2A, Hocking Valley, Marseilles and others.
In common practice, 100-odd links of hook chain were used to form a continuous loop belt conveyor. The long wire links essentially mimicked the use of attachment links (and cross-members) in flat chain.
Hook chain was marketed primarily by Noffsinger Mfg. Co., Greeley, Colorado, for many years and is still produced today for the potato harvesting industry in both heavy- and wide-gauge links. The use of this chain faded in corn sheller applications with the advent of the cylinder-style corn sheller. With that shift in sheller design, manufacture of narrow versions of this product was phased out.
The challenge of correct chain
Restoration work on older pieces of farm equipment is often fraught with pitfalls. Hardware, paint, and missing and broken parts can pose serious but manageable challenges. While some can be overcome through basic ingenuity, others bring the project to a full stop.
In my restoration projects, few things have troubled me as much as the availability of these two critical types of chain. Detachable-link malleable iron chain and the conveyor chain (sometimes called "hook chain") used on typical cob rakes in the larger freestanding two-hole shellers have posed the greatest obstacle.
I was extremely fortunate to access a relatively large inventory of malleable iron chain several years ago at an implement dealer auction in Iowa. Those stocks have been invaluable in a number of projects.
More recently, I have set up the means to accurately fabricate hook chain. Through the efforts of some very talented friends at a local machine shop, we have created a six-step process, complete with the appropriate jigs, to produce the chain with excellent repeatability.
Without these two sources, my efforts to support these restorations would have ended years ago. I am happy to continue to be a part of many careful and accurate restorations of rare John Deere two-hole shellers.
Ted "Dutch" deHaan is a retired steel automation engineer. He is a restorer of early machines and implements, and is the author of articles on restoration of antique corn shellers and cider presses. Email him at firstname.lastname@example.org.