IMPROVEMENTS IŃ MACHINERY OR TOOLS FOR DRILLING AND BORING
Year: 1857

page_text: on for Letters Latent was not given within' the time prescribed
- by the Act:)*
PROVISIONAL SPECIFICATION left by Andrew Peddie How at the Office
of the Commissioners of Patents, with his Petition, on the 26th
February 1857.
J, ANDREW PEDDIE How, of Mark Lane, in the City of London, Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IŃ
MACHINERY OR TOOLS FOR DRILLING AND BORING," to be as follows:
"My Invention consists in constructing drilling and boring machinery (com-
monly called "ratchet drills ") in such manner that the teeth in the ratchet
wheel may be acted on alternately by two' pauls, which' take into the same
side of the centre of the ratchet wheel; whereby a continuous rotary motion
is imparted to the ratchet wheel and drill stock, in which the drill is fixed by
a vibratory or oscillating motion given to the stock in which the pauls áre
jointed. This stock is formed or furnished' with handles to work it by; it is
jointed on a pin between the forked end of the main stock in which' the
ratchet wheel is inserted, this end being. prolonged for that purpose; the other
end of the main stock forms a handle for holding the machine while at work.
The pauls are jointed in the stock, one on each side of the forks, but their
free ends are brought to bear or take into the ratclict on the same side of the
centre; springs are provided for pressing them into the teeth. If necessary,
either of the vibrating stock handles may be removed while it is worked by
one person. The ratchet wheel is fixed or formed on a tube, which is slotted
Jongitudinally in a number of places; a cylinder (much shorter than the

page_text: tubo, and having recesses cut in it) is inserted in it, each recess corresponds to
one of the slots in the tube; short segments of screws are fixed in these
recesses, the teeth or screw threads of which project through the slots and
beyond the outer surface of the slotted tube. The whole of the screw
segments are so placed that the threads tako readily into an internal screw
which is formed in the interior of a casing which covers the slotted tube,
screw, and barrel. The end of the tube is solid, part of which projects
through the casing, and has a screw formed on it, on which a nut.is placed to
keep the casing in place. An ordinary conical centre point is formed on the
part which passes through the nut. The casing may be formed hexagonally,
so as to be easily laid hold of by a spanner or by the hand to turn it. The
boring bit or drill is inserted in a suitable socket formed 'in the end of
the cylinder, in which the screw segments are fixed. By the turning of the
casing in one direction the segments of the screws are made to traverse
longitudinally in the slots, and consequently draw the cylinder and drill within
the ratchet wheel and tube away from the work. On turning the casing in
the reverse direction the drilling bit is projected from the tube, and made to
bear against the work. It will thus be seen that holes may be drilled in
more difficult places than can be done by the common ratchet brace.'
In the improved brace the bits or drills are entirely drawn within the body
of the brace, thus making the whole the length of the bit or drill shorter
than the common. boring apparatus. I likewise use the hollow slotted tubo
(for drawing in the drill, in connection with the ordinary method of working
ratchet braces; or, in connection with the same, I make use of a paul formed
on the end of the handle nearest to the ratchet wheel, and which takes into
its teeth when being moved in one direction, but releases itself from the teeth
on being moved in a contrary direction. This is done by pivotting the handle
between the forked ends of the stock on a pin, another pin is inserted through
the fork and handle, which pin is fast in the forks; but the hole in the handle
is slotted, to allow as much play on the pin as is necessary to lay hold of tho
ratchet, wheel in its forward and release it in its backward stroke.
.