IMPROVEMENTS IN BIT STOCKS
Year: 1878

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents, 66,
Chancery Lane, in the County of Middlesex, Mechanical Draughtsman, for the
Invention of "IMPROVEMENTS IN BIT STOCKS." A communication from abroad
by Charles Mason Knowles, of New London, in the State of Connecticut,
United States of America.
Sealed the 20th May 1879, and dated the 27th November 1878.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton at
the Office of the Commissioners of Patents on the 27th November 1878.
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. "IMPROVEMENTS IN BIT STOCKS."
[A communication from abroad by Charles Mason Knowles, of New London, in the
State of Connecticut, United States of America.]
The object of this Invention is to secure a firm hold for the shank of the bit in
the stock or brace by means which shall so clamp said shank at two places or
distances apart, as that any movement of the bit in the socket of the stock, brace,
or tool holders will be positively and effectually prevented.
The Invention consists in a combination with a split spring socket having a
conical outer extremity of a primary tightening or clamping ferrule, the interior
surface of which is constructed to fit said conical extremity of the split spring
socket, and a secondary clamping ferrule formed with an oval hole, to allow of its
fitting easily over the expanded socket and shank portion of the stock or brace,
and having an external screw thread, which is made to fit an internal screw thread
in the aforesaid primary clamping ferrule.
The action of this arrangement is to press the divided parts of the socket toward
each other, and thereby to grip the bit firmly.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Vincent Newton in the Great Seal Patent Office on the 27th
May 1879.
'
"
ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman. IMPROVEMENTS IN BIT STOCKS."
A communication from abroad by Charles Mason Knowles, of New London, in the
State of Connecticut, United States of America.
The object of this Invention is to secure a firm hold for the shank of the bit in
the stock or brace by means which shall so clamp said shank at two places or
distances apart as that any movement of the bit in the socket of the stock, brace, or
tool holder will be positively and effectually prevented.
The Invention consists in a combination with a split spring socket having a
conical outer extremity of a primary tightening or clamping ferrule, the interior
surface of which is constructed to fit said conical extremity of the split spring
socket, and a secondary clamping ferrule formed with an oval hole, to allow of its
fitting easily over the expanded socket and shank portion of the stock or brace, and
having an external screw thread which is made to fit an internal screw thread in
the aforesaid primary clamping ferrule, such secondary clamping ferrule being
caused by turning the primary clamping ferrule to press upon the outside of the split
socket, and thereby to force the parts of the said socket against which it bears
toward each other.. Thus the said parts will be caused to bear firmly against
the shank of the bit, while at the same time the primary clamping ferrule will
be drawn over the conical extremity of the split socket, and will make that
part of said socket bear also against the shank of the bit.
Having thus specified the object and nature of the Invention, I will now proceed
to describe the details of the Invention with reference to the accompanying
Drawing.
Fig. 1 represents a partially sectional side view of a bit, stock, or brace, con-
structed in accordance with the Invention; Fig. 2 is a transverse section on the
line x, x; and Fig. 3, a longitudinal section on the line y, y.
A is the shield, button or head of a bit, stock, or brace fitted on or over the
spindle portion band bearing against an adjustable screw bearing B on said spindle
portion, or these several parts may be otherwise suitably contracted and fitted.
C is the cranked portion of the stock or brace.
D represents the split spring socket of the stock or brace for holding the bit E.
This socket is constructed with interior bearings e, e', for said bit. These bearings
are separated from each other by recesses of formed in the interior of the socket.
The outer extremity g of the split spring socket is of conical construction. The
split 8 of the socket extends a considerable distance into the cranked portion of the
brace, as shewn in Figures 1 and 3.
G is a primary clamping ferrule, having an interior conical bearing h constructed
to fit the conical extremity g of the spring socket, as shewn in Figures 1 and 3.
His a secondary screw clamping ferrule, which slips easily on the exterior of the
socket and shank portion of the stock or brace, the interior of the said ferrule being
wholly or partially of oval or oblong form, as shewn in Fig. 2, and the transverse
section of that portion of the shank or socket to which it fits being externally of
corresponding form, or both ferrule and shank or socket being of other suitable form,
whereby the said ferrule is prevented from turning on the said shank.
The spring socket D is tapering on its exterior, having its larger part at the base
of its conical extremity, and as there is preferably but one split in the said socket,
it follows that it can expand or contract only in a line at right angles or there-
abouts with the longitudinal axis of the said socket, and at right angles or there-
abouts with the said split s.
In its normal position the said socket has its greatest diameter in the said line of
expansion, and the ferrule H has its oval or oblong central opening made of such

page_text: size and is so placed in relation with the socket and shank of the brace that it
cannot turn on the socket or shank when it is engaged with the ferrule G. On the
exterior of the ferrule H is a screw thread k, which fits a female screw thread / in
the ferrule G.
From this description it will be seen that the turning of the ferrule G may be
made to cause the ferrule H to approach the conical extremity of the socket or
contrariwise, and that when it does so approach it will not only force the conical
interior bearing of the ferrule G upon the conical extremity of the socket, but will
be itself caused to press against the sides of the said socket over the bearings e,
and press the said bearings against the shank of the bit. The bit is thus engaged
by the bearings e, e¹, at two places, and is in consequence held with positive firm-
ness, and the relation of the parts is such that a very slight turning of the
ferrule G is sufficient to clamp or release a bit properly placed in the said socket.
It will also be seen that by turning the ferrule G before inserting the bit the
socket D will be adjusted to receive large or small bits through a wide range of
sizes.
The Invention is also applicable to bit stocks or tool holders which instead of
being cranked are straight throughout their length.
Having now set forth the nature of the Invention of "Improvements in Bit
Stocks," as communicated to me from abroad, and explained the manner of carrying
the same into effect, I wish it to be understood that under the above in part recited
Letters Patent I claim,-
The combination with the split spring socket having a conical extremity of a
primary clamping ferrule having a conical interior bearing, and a secondary clamping
ferrule having a male screw thread on its exterior, arranged to fit a female screw
thread on or in the interior of the primary clamping ferrule, substantially as and
for the purpose specified.
In witness whereof, I, the said Alfred Vincent Newton, have hereunto set
my hand and seal, the Twenty seventh day of May, in the year of our Lord
One thousand eight hundred and seventy nine.
A. V. NEWTON. (L.S.)