IMPROVEMENTS IN APPARATUS FOR CUTTING INTERNAL SCREW THREADS
Year: 1873

page_text: LETTERS PATENT to William Lloyd Wiso, of Chandos Chambers,
Adelphi, in the County of Middlesex, Patent Agent, for the Inven-
tion of "IMPROVEMENTS IN APPARATUS FOR CUTTING INTERNAL SCREW
THREADS."-A communication from abroad by Mr. John MoFethries,
Director of the Kovroff Works of the Moscow and Nijni Novgorod
Railway, Russia.
Scaled the 25th April 1878, and dated the 27th February 1873.
PROVISIONAL SPECIFICATION left by the said William Lloyd Wiso
at the Office of the Commissioners of Patents, with his Petition, on
the 27th February 1873.
I, WILLIAM LLOYD WISE, of Chandos Chambers, Adolphi, in the
5 County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN APPARATUS FOR CUTTING INTERNAL
SCREW THREADS," to be as follows:—

page_text: The improved apparatus consists essentially of a main body, with
sliding dies or cutters and means for adjusting the same, so that a
variety of threads and sizes of threads may be cut by the one tool.
The main body is formed with a hole or passage through its centre to
receive an adjustable spindle having a conical lower end or wedge,
this spindle being screwed into the main body of the tool, and being
capable of being secured in position as required by suitable check nuts.
The lower part of the main body is suitably slotted or formed to receive
four or any other convenient number of dies or cutters radiating from
the centre of the tool. The cutting faces of these dies are concave, and 1
their inner or rear ends are formed with knife edges, the upper corners
of which are chamfered for the reception of the conical spindle end or
wedge, so that it may force all the dies or cutters outwards simul-
taneously as it is moved towards them, but when it is drawn back they
may be moved inward to any required extent.
The apparatus may be provided with an indox to facilitato the adjust-
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Lloyd Wise in the Great Seal Patent
Office on the 22nd August 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
LLOYD WISE, of Chandos Chambers, Adelphi, in the County of Middle-
sex, Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of February, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Lloyd Wise, Her special license
that I, the said William Lloyd Wisc, my executors, administrators,
and assigns, or such others as I, the said William Lloyd Wise, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,

page_text: the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN APPARATUS FOR CUTTING INTERNAL SCREW THREADS," a communication to
me from abroad by Mr. John McFethrics, Director of the Kovroff
Works of the Moscow and Nijni Novgorod Railway, Russia, upon the
condition (amongst others) that I, the said William Lloyd Wise, my
excoutors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describo and
ascertain the nature of the said Invention, and in what manner the
samo was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Lloyd Wise, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, and the Drawings therein referred to,
(that is to say) :-
This Invention relates to apparatus to be used in lieu of the ordinary
screw-cutting tap for cutting internal scrow threads.
The improved apparatus consists essentially of a main body, with
sliding dies or cutters and means for adjusting the same, so that a
variety of threads and sizes of threads may be cut by the one tool.
The main body is formed with a hole or passage through its centro to
receive an adjustable spindle having a conical lower end or wedge, this.
spindle being screwed into the main body of the tool, and being capable
of being secured in position as required by suitable chock nuts. Tho
lower part of the main body is suitably slotted or formed to receive four
or any other convenient number of dics or cutters radiating from tho
centre of the tool. The cutting faces of these dios are concave, and their
inner or rear ends are formed with knife edges, the upper corners of
which are chamfered for the reception of the conical spindle end or
wedge, so that it may force all the dies or cutters outwards simul-
taneously as it is moved towards them, but when it is drawn back thoy
may be moved inward to any required extent.
The apparatus may be provided with an index to facilitate the adjust-
ment of the dies or cutters.
Fig. 1 of the accompanying Drawings is a plan of part of an internal
screw-cutting apparatus according to this Invention,

page_text: Fig. 2 is a side clevation of the apparatus.
Fig. 3 is a view of the lower end.
Fig. 4 is a vertical sectional elevation; Fig. 5 is a horizontal section
taken in the line of A, B, of Fig. 4.
Fig. O is a vertical sectional clevation of the apparatus as made with
an index in lieu of the check nuts to facilitate the adjustment of the dies
or cutters.
a is the main body; b, the hole or passage through its centro; c, the
adjustable spindle formed with a conical lower end d, and screwed at e
into the body a; f, g, are the check nuts for securing the spindle in
position as required; h are the dies or cutters fitting into slots in the
lower end of the body a, and made with concave cutting faces forming
two cutting edges i, i, (Fig. 5) so that the dies will cut in either
direction according to the way the apparatus is turned. The inner ends
of these dies are formed with knife edges %, chamfered at / to receive the
conical end of the spindle.
In the Drawing the dies are shown to have been forced out by the
adjustable spindle to their largest working diameter. To draw thom
back it is only necessary to turn the spindle so as to screw or raise it
further out of the body, thereby causing its conical end to leave the dies,
which may then be gently tapped back as may be required, the con-
centricity of their cutting faces when working being maintained by tho
cone or wedge of the spindle, which forms a backing for them, except
when they are moved inwards, until their cutting faces are flush with
the turned part of the body, in which position their rear ends fill up
the
hole b, leaving only a small pointed indenturo at the top, formed by the
chamfered corners already mentioned.
The upper end of the body a is made square, or of other convenient
form, to receive a handle; key, or wrench, by which the tap can be
turned.
In Fig. 6 the check nuts described with reference to the preceding
arrangement are dispensed with, a part c' of the adjustable spindle being
suitably faced down and graduated, so that the position in relation to it

page_text: It will be obvious that a wedge may be substituted for the conical end
without departing from the distinctive character of the Invention.
Having described the nature of the said Invention for "Improvements
in Apparatus for Cutting Internal Scrow Threads," and having explained
the manner of carrying the same into practical effect, I hereby declare
what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent to be,-
First. The combination in an apparatus for cutting internal screw
threads of a main body with sliding dies or cutters and means for
adjusting the same, so that a variety of threads and sizes of threads may
be out by the one tool, as above described.
Secondly. The application of dies with the above-described concavo
cutting faces to the cutting of internal screw threads.
Thirdly. The adjustment of the dies by the use of check nuts in con-
junction with the adjustable spindle, substantially as described.
Lastly. The application of an index, as herein-before described, to
facilitate the adjustment of the dies or cutters for cutting internal screw
threads of different sizes.
In witness whereof, I, the said William Lloyd Wise, have hereunto
set my hand and seal, this Twenty-first day of August, in the