The history of the cove-and-pin joint
Megan Fitzpatrick explores the history behind the Knapp dovetailing machine, one of the first machines to efficiently manufacture first class drawers
If you have an antique piece of furniture that features drawers with a curious-looking half-circle joint, you can be almost certain that it was made in a North American factory between 1871 and 1900. While it came to be known as the Knapp Joint, the joint is also variously described by its appearance: the pin and cove, scallop and dowel, scallop and peg, pin and scallop, and half-moon.
Why the (rather brief) departure from dovetails? By the second half of the 19th century, most furniture in America was made by machines in industrialized factories—with the exception of fine drawers. Though people were patenting machines that could produce dovetails (106 patents for the like applied for between 1833 and 1900!), no one had yet developed an appealing way to cut more than one uniform pin and tail at a time. (See the Burley & Putman Dovetailing machine, patent nos. 12,122 and 26,647)
High-quality drawers were still being produced by hand, and while a skilled craftsman could turn out perhaps 20 drawers a day, that wasn’t nearly fast enough to keep pace with the production of furniture for which said drawers were intended. Handwork was holding up the factory output.
Instead of focusing on a machine for cutting dovetails, Charles B. Knapp, of Waterloo, Wis., simply rethought the joint.
His 1867 patent (no. 63,532) describes his inventive approach as “of that class of joints known by the general name of a ‘tenon and mortise joint,’ the particular form of the tenon in this instance being in cross-section, round or circular, with the mortise or hole of a corresponding shape and size thereto, so that when placed one within the other they will form a close and tight joint.” It’s a series of…