Description
Ferodo vintage drilling and counterboring tool for brake-lining rivets GB431711/1935
The tool is composed of three separate parts, the body (the inner section); the collar (the outter section) and the bit. The tool has two operating positions: ‘lock’ and ‘release’. The bit is can be slid in and out when unlocked and is held fast when in the lock position. The original bit which is similarly branded and patent marked has depth graduations on it When you want to adjust the depth of the bit (or remove it), you turn the body 1/4 turn (90 deg) clockwise with respect to the collar, which is the release position.
Shank appears to be 5/16″ wide.
Patent information can be found here:
https://worldwide.espacenet.com/publicationDetails/biblio?FT=D&date=19350715&DB=EPODOC&locale=en_EP&CC=GB&NR=431711A&KC=A&ND=4