These tools are now made with so many improved features that there is really no excuse for getting poor tools.
The illustrations show merely the heads and the lower operating parts of the tools. Fig. 271 shows a metal-clad ball-bearing head, so called, as its under side is completely encased in metal securely screwed to the wood and revolving against the ball thrust bearing.
D represents a concealed ratchet in which the cam ring governs the ratchet, and, being in line with the bit, makes it more convenient in handling than when it is at right angles. The ratchet parts are entirely enclosed, thus keeping out moisture and dirt, retaining lubrication and protecting the users' hands.
The ratchet mechanism is interchangeable, and may be taken apart by removing one screw. The two-piece clutch, which is drop forged, is backed by a very strong spring, insuring a secure lock. When locked, ten teeth are in engagement, while five are employed while working at a ratchet. It has universal jaws (G) for both wood and metal workers.
In Fig. 272, B represents a regular ball bearing head, with the wood screw on the large spindle and three small screws to prevent its working loose. This also has a ball thrust. E is the ratchet box, and this shows the gear teeth cut on the extra heavy spindle, and encased, so that the user's hands are protected from the teeth.
The interlocking jaws (H), which are best for taper shanks, hold up to No. 2 Clark's expansion, and are therefore particularly adapted for carpenter's use.
Fig. 271. Fig. 272. Fig. 273.
Types of Bit Braces.
In Fig. 273 the plain bearing head (C) has no ball thrust. The head is screwed on the spindle and held from turning off by two small screws. The open ratchet (F) shows the gear pinned to the spindle and exposed. This has alligator jaws (J), and will hold all ordinary size taper shank bits, also small and medium round shank bits or drills.