Quimby S. Backus brace, patented November 5, 1872

Quimby Backus No.8 brace - Patented November 5, 1872.

Quimby S. Backus Patented November 5, 1872

This little brace bears the patent date, Nov. 5, 1872 (US Patent No. 132,791). However, even though the inventor's residence was Millers Falls, Massachusetts at the time the patent was granted, by the time this example was made, the Backus firm had taken up residence in Holyoke, Massachusetts, probably around 1878. That makes this brace about 130 years old !

The makers mark on the chuck is quite indistinct, so I boosted contrast and brightness, converted to greyscale, and then inverted to a negative image. It is now possible to see the Nov. 5, 1872 date as well as the Holyoke, Mass. company location.

US Patent No.132,791, edited for television

The wrist handle appears to follow the patent drawing, but all that may be intended is for the reader of the patent actually to make the invention, as the law requires.

The brace appears to be the No.8 size.

The chuck follows the patent drawing exactly.

The actual patent claim only applies to the jaws, although the handle is indeed mentioned in passing. The pad isn't mentioned in the claim ... And that's the part on this particular brace that's too tight to turn.

Note that the witnesses to the drawing (Henry A. Miller and C.L. Evert) aren't the same as the witnesses to Mr. Quimby's signature, A.N. Marr and Edm. F. Brown. I can't decipher the attorney's hand.

Quimby Backus No.29 brace - Patented November 16, 1880 and November 29, 1881

	Whatever patent dates might have been marked on the chuck shell of this brace have been obliterated by wrench marks, but the patented features are utterly distinctive of two Backus patents: U.S. Patent No. 234,517 (November 16, 1880) for the ratchet selector mechanism and U.S. Patent No.250,047 (November 29, 1881) for the chuck's jaws and their retention mechanism. There was an issue with this brace's ratchet selector, as the pin connecting to the selector sleeve was gone. I made the one you see here by trial & error, as the screw size is midway between a No.8 and a No.10 U.S. Standard fine-thread machine screw. The patent isn't much help, as there's no clue how the pin is retained. I found that the number of threads per inch is 32, as a No.8-32 screw would go in, albeit way too loosely to be of any other use. I simply turned the OD of my new pin a little bigger than a No.8 screw, started chasing threads, and kept on trial fitting the screw until it actually fit. I was lucky (or sufficiently sharp-eyed) to get the 1/4 inch CRS steel bar back into the collet in the right relationship to the chasing tool after every trial fit. My loupe helped a lot.
	Here's the missing Fig.2 from my capture of page 1 of the Quimby patent: Item J in the patent drawing is the selector pin, but it's shown with two problems: (1) there's nothing to keep it in place, and (2) the pin interferes with the sides of the semi-cylindrical cutout in the frame that allows the pin to swing through a 180 degree arc. I had to re-invent it ! The top end of my pin is a 1/8 inch length of No.9-32 threads; then there's 5/32 inch of 0.145 inch diameter to clear the sides of the cutout, and lastly an 11/32 inch length of 0.1035 inch diameter to fit the cross-drilled hole in the ratchet pawl. The pitch diameter of the No.9-32 screw is 0.154 inch, and its OD is 0.1735. The saw-cut slot in the outer end of the selector pin slightly damaged the last thread on the screw, so it tightens at just the right place in the selector sleeve. That was pure luck ... The pin does not have to be very strong, as the ratchet pawl turns freely when the selector sleeve is pulled out to disengage the pawl. My finished selector pin. Here is the other patented feature of this brace, the jaw retention mechanism of U.S. Patent No.234,517: The jaws are only meant to center the cylindrical part of the drill bit; the square shank of the bit fits into a square hole in the socket of the chuck and does the driving. Nevertheless, this pair of jaws survived all the wrench insults that the chuck shell received. I have seen a number of examples of this mechanism, but in the others the copper-plated flat springs have usually been rusted away.
	I've rearranged the elements of Mr. Quimby's U.S. Patent No.234,517 drawing, the better to fit the present format. The actual brace follows the drawing very closely, the principal difference being that the springs are retained with machine screws, not just the single rivet which would have been awkward to detach for replacement of a broken spring. The attorney's signature is more legible here: J.C. Tasker, but it's a different person than on the No.132,791 patent. Again, the witnesses to the patent text signature (Frank B. Spalter and G.S. Loud) differ from the witnesses to the patent drawing itself (F.H. Schott and W.E. Chaffee). The pads of both braces turn stiffly at first but then free up pleasantly once the brace is put into use and an oil film spreads over the inside of the hole. They are apparently of the same design - and quite difficult to disassemble, as I think the retention mechanism is permanently glued in place and inaccessible from the outside. One oils them only from the outside, simply by placing the lubricant along the very tight fit between the wood and the frame ... followed by lots of elbow grease to distribute the oil. In the 250,047 patent, the drawing witnesses are John H. Stout and C.J. Munn, but the text signatures are those of the same two men. There was apparently no attorney of record for this patent, in contrast to the earlier patent shown at left.
	Here are the rest of the two Quimby S. Backus patents, 234,517 on the left and 250,047 below. Note that the essence and enforceable legal portion of each patent is the Claims section at the very end of each patent's text. Randy Roeder (a librarian by profession) has published a fine biography of Quimby S. Backus, including his various businesses and his legal battles with the owners of other patents which he was found to have infringed. His losses in the legal arena simply spurred Quimby Backus to even greater inventiveness so as to maintain a stock of defensible patent designs in the braces that he made. The second brace on this page was backus's finest hour in Mr. Roeder's estimation.