"Projects" at georgesbasement.com

8. Refurbishing a factory second No.2 drill
This was an otherwise normal 2B drill with hardwood handles, but with a specially adapted Jacobs Model 4364 Rubber Flex chuck, 3/8 inch capacity.
Model 2B with Jacobs chuck
Model 2B with Jacobs chuck
The Jacobs chuck is marked with the U.S. Patent No. 2,346,706 and with a pending patent, which turns out to be No. 2,459,899.  Another pertinent patent is No. 2,683,041.
The rod through the handle, hefty at 7/16-18, had an unsightly nut and washer which I cut off flush with the end of the handle.  Whoever fitted the chuck also added a larger threaded sleeve over the original drill's 3/8-24 spindle threads. I made a new, larger bronze LRRCW to replace the lost roller and to allow the running clearance of the gears to be properly adjusted.  The patent drawing for the body of the chuck matches the outline of the actual chuck, but the rubber spider for the three jaws does not match - one has to infer the design from U.S. Patent No. 2,459,899.
Markings on crank
Repaired handle
US Pat's No. 2,346,706 & 2,459,899
Jacobs Patent No. 2,683,041 chuck design
Jacobs jaw designs, US Pat's No. 2,459,899 & 2,683,041
Markings: "[Star] No. 2B, Millers Falls Co., Millers Falls, Mass., U.S.A."
The frame had been tapped and a piece of threaded rod inserted through the handle.
Chuck is marked "Patent 2346706 & Pat. Pend." (U.S. Pat. No. 2,459,899) & "Model 4364."
Patent drawing from U.S. Pat. No. 2,683,041.
Jaws, 2,459,899 & 2,683,041 patents.
Referring to Randy Roeder's fine website, A Millers Falls Home Page, the No.2B drill with LRRCW was only made from 1912 to 1938.  The Jacobs chuck was made between about 1944 after the first patent issued and 1949 when the second patent issued.  Therefore, the marriage was conducted outside the Millers Falls organization, using a cast-off No.2B drill.  I cannot find any other Model 4364 chucks or even any reference to them on the Internet.  I have seen some 1/4 inch capacity Rubber Flex chucks on power drills, however.