IMPROVEMENTS IN DRILLING APPARATUS AND MECHANISM
Year: 1881

page_text: LETTERS PATENT to Charles Stuart, of Bletchley Iron Works, Fenny
Stratford, in the County of Bucks, Mechanical Engineer, for an Invention of
"IMPROVEMENTS IN DRILLING APPARATUS AND MECHANISM."
PROVISIONAL SPECIFICATION left by the said Charles Stuart at the Office
of the Commissioners of Patents on the 29th November 1881.
"
CHARLES STUART, of Bletchley Iron Works, Fenny Stratford, in the County of
Bucks, Mechanical Engineer. IMPROVEMENTS. IN DRILLING APPARATUS AND
MECHANISM."
This Invention consists in forming an outer shell or casing to enclose the
drilling mechanism, and in the manner of producing a continuous rotary moveinent
of the drill spindle, combined with a selfacting forward or feed motion of the
drill.
The casing has the advantage of combining the whole internal arrangements in
one, by which means the portability of the machine is greatly increased, and at the
same time the mechanism is entirely protected from injury arising from dust or
otherwise. The case contains also within itself and in the line of its own axis the
means of withstanding the great strain produced in giving the forward movement
to the drill, so that this portion of the machine may be separated from the arins
and clamps for use in a confined space.
The forward motion is produced by forming a feather on the feed spindle with
a partial thread cut on its surface, working within an internally screwed socket
with a slot cut in its inner surface in a direction parallel to its axis, and corre-
sponding in size with the above feather, so that with every revolution of the feed
spindle an arresting or reciprocating power is given to the socket and a forward
movement obtained.
For the continuous rotary motion three bevel wheels are arranged in the usual
manner in connection with the drill spindle. Motion is given to the handle and
spindle attached to the side bevel wheel, which moves the upper and lower wheels,
causing them to revolve in opposite directions. These two wheels have cast on
their respective faces radially cut ratchet teeth, which, whilst revolving, gear into
corresponding crown cut ratchet wheels, fitted with sliding feathers or their
equivalents upon the drill spindle, thus causing the drill to revolve continuously,
one set of ratchets travelling always in the opposite direction to the other.
ratchet wheels are held in their respective gearings by the action of a spiral spring
or springs, allowing the teeth to pass one another when travelling in opposite
directions; this arrangement gives additional strength and prevents loss of time
through backlash.
These
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Stuart in the Great Seal Patent Office on the 26th May
1882.
CHARLES STUART, of Bletchley Iron Works, Fenny Stratford, in the County of
Bucks, Mechanical Engineer. "IMPROVEMENTS IN DRILLING APPARATUS AND
MECHANISM."
My Invention consists in forming an outer shell or casing to enclose the drilling
mechanism, and in the manner of producing a continuous rotary movement of the
drill spindle, combined with a self acting forward or feed motion of the drill.
The casing has the following advantages, viz. :-It combines the whole internal
arrangement in one, thus greatly increasing the portability of the drilling machine,
and at the same time protecting the works entirely from injury from dust or
accident. It also contains within itself and in the line of its own axis the means
of withstanding the great strain produced in giving a forward or feed motion to
the drill, so that this portion of the machine may be separated from the arms and
clamp for use in a confined space.
To produce this motion a feather is constructed on the feed spindle, which has a
partly formed thread cut on its periphery and working within an internally screwed
nut, having a slot cut on its inner surface parallel to its axis and corresponding in
size with the before mentioned feather, by which means, with every revolution of
the feed spindle, an arresting or reciprocating power is given to the screwed nut,
and thus the forward movement is obtained.
In further explanation of the said Invention I annex a Drawing, in which
A and A' represent the handle to give motion to C or C¹.
C, C, C, are cog wheels geared into each other.
D, D¹, are crown cut ratchet wheels, one attached to and the other to the
drill spindle F, giving it a sliding rotary motion.
G is a female threaded spindle into which F is screwed, allowing it to have the
necessary length of feed motion.
H is the feed nut arranged to give the necessary resistance to G.
By the handle the resistance of spring L which regulates the feed may be
varied at pleasure.
G may be moved independently of the spindle F, and thus F brought back to
its normal position.
Having thus explained the nature of my Invention, I wish it to be understood
that I do not confine myself to the exact configuration herein described, but that I
claim the construction of an outer envelope or shell protecting the several parts
and motions of a double acting self feeding ratchet drill, substantially as herein
set forth.
In witness whereof, I, the said Charles Stuart, have hereunto set my hand
and seal, this Twenty-fifth day of May, One thousand eight hundred and
C. STUART. (L.S.)