IMPROVEMENTS IN SCREW STOCKS AND DYAN"
Year: 1883

page_text: LETTERS PATENT to William John M'Cormack of Paignton in the county
of Devon for an Invention of "IMPROVEMENTS IN SCREW STOCKS AND
DYAN"
PROVISIONAL SPECIFICATION left by the said William John McCormack
at the Office of the Commissioners of Patents on the 29th May 1883.
WILLIAM JOHN MCCORMACK of Paignton, in the county of Devon
MENTS IN SCREW STOCKS AND DIES
"
"IMPROVE-
This invention relates to improvements in the construction of that class of
stocks and dies chiefly applicable for cutting screw threads on pipes for which
Letters Patent were granted to me N° 2158 dated the thirtieth day of May one
thousand eight hundred and seventy nine and the object of my present
improvements is to simplify the construction of such apparatus also to so construct
the apparatus as to render it more suitable for screw threading bolts of different
sizes for engineers' use.
In carrying out my present improvements the stock or die plate is formed with
a central hole into which open four horizontal holes or openings passing edgeways
through the stock from the ends and in a nearly radial direction with the centre of
the hole in the stock all as described in the specification of my said former Letters
Patent;
the dies or bits are now provided with two sets of threads or teeth at
both ends so that they may be reversed and placed in four different positions and
they are preferably formed of round steel; the said dies pass into the herein-before
described radial holes and when the dies are made of round metal the said holes
are provided with a key and the dies with a key-way, so that the dies are held
perfectly firm as in my former Letters Patent, the dies can however be made of
other section of steel, the radial holes in the stock corresponding in shape and in
this case no key or key-way will be required; the dies are according to my present
improvements provided near each end with a groove or grooves.
Each end of the stock or die plate is formed with a screw threaded projection

page_text: on which screws a collar or ferrule as before, but the said ferrule is now
formed with a flange or rim, which flange takes into the grooves of each pair
of dies.
By this arrangement if the ferrules be turned by means of a key or otherwise
the dies are moved towards or withdrawn from the centre of the stock or die plate
according to the direction in which the ferrules are turned.
The placing of the dies radially or nearly so in the manner described enables
them to be adjusted to any circle and their being reversible and being cut with
two sets of teeth or threads at both ends allows of their being placed in four
different positions so as to screw four or more sizes of bolts to " Whitworth
pitch
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William John McCormack in the Great Seal Patent Office on the.
26th November 1883.
WILLIAM JOHN MCCORMACK of Paignton in the county of Devon "IMPROVE-
MENTS IN SCREW STOCKS AND DIES
"
This invention relates to improvements in the construction of that class of
stocks and dies chiefly applicable for cutting screw threads on pipes for which
Letters Patent were granted to me N° 2158 dated the thirtieth day of May one
thousand eight hundred and seventy nine and the object of my present
improvements is to simplify the construction of such apparatus also to so construct
the apparatus as to render it more suitable for screw threading bolts of different
sizes for engineers' use.
In order to enable my invention to be fully understood I will proceed to
describe the same by reference to the accompanying drawing in which figure 1,
represents a plan partly in section of my improved stock and dies and figure 2, a
side view of the same. Similar letters of reference in both the figures represent
similar parts.
A, represents the stock or die plate which is formed with a central hole a, into
which open four horizontal holes or openings passing edgeways through the
stock A, from the ends and in a nearly radial direction with the centre of the hole
in the stock as shewn, all as described in the specification of my said former Letters
Patent; B, B, are the dies or bits which are now provided with two sets of threads
or teeth at both ends so that they may be reversed and placed in four different
positions and they are preferably formed of round steel; the said dies B, pass into
the hereinbefore described radial holes and when the dies B, are made of round
metal the said holes are provided with a key C, and the dies with a key-way C', so
that the dies B, are held perfectly firm as in my former Letters Patent, the dies
can however be made of other section of steel, the radial holes in the stock
corresponding in shape and in this case no key or key-way will be required;
the dies B, are according to my present improvements provided near each end with
a groove F.
Each end of the stock or die plate A, is formed with a screw threaded
projection D, on which screws a collar or ferrule E, as before, but the said ferrule
is now formed with a flange or rim E¹, which flange E', takes into the groove F, of
each pair of dies B.
By this arrangement if the ferrules E, be turned by means of a key or otherwise
the dies B, are moved towards or withdrawn from the centre of the stock or die
plate according to the direction in which the ferrules are turned; G, G, are the
handles of the apparatus.
The placing of the dies radially or nearly so in the manner described enables
them to be adjusted to any circle and their being reversible and being cut with
two sets of teeth or threads at both ends allows of their being placed in four or
more different positions so as to screw four or more sizes of bolts to "Whitworth"
pitch.
Having thus described my said invention and the manner of performing the
same what I claim is :-
Firstly. The improved screw stock or die plate constructed arranged and
operating substantially as hereinbefore described and represented in the accom-
panying drawing.

page_text: Secondly. The employment in combination with a screw stock or die plate as
herein beforo described of dies or bits having two sets of threads or teeth at both
ends as and for the purposes hereinbefore described and represented in the
accompanying drawing.
Thirdly. The method herein described of forcing the dies up to the work and of
withdrawing them as required by means of a screw ferrule having a flange working
in a groove in the dies or bits substantially in the manner herein before described
and represented in the accompanying drawing.
In witness whereof I the said William John McCormack have hereto set my
hand and seal this twenty first day of November in the year of our Lord one
thousand eight hundred and eighty three