Im- PROVEMENTS IN WOOD SCREWS AND IN THE MEANS EMPLOYED IN THEIR MANUFACTURE
Year: 1867

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "Im-
PROVEMENTS IN WOOD SCREWS AND IN THE MEANS EMPLOYED IN THEIR
MANUFACTURE." -A communication from abroad by John Waldron Hoard,
and Soloman Whipple Young, of Providence, in the State of Rhode
Island, United States of America.
Sealed the 10th December 1867, and dated the 17th June 1867.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents, with his Petition, on the 17th
June 1867.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN WOOD SCREWS AND IN THE MEANS EMPLOYED IN THEIR
MANUFACTURE," a communication to me from abroad by John Waldron Hoard
and Soloman Whipple Young, of Providence, in the State of Rhode Island,
United States of America, to be as follows:-
This Invention relates, firstly, to wood screws, and particularly to those
known as "gimlet pointed" screws, and consists in forming in the shank of

page_text: the screw one or more longitudinal grooves, flat sides, or indentations, which
extend upwards from the point of the screw and are transverse to the thread
of the same. By this means one or more cutting edges are produced in the
screw which by removing the wood materially assist the entrance of the screw
more particularly in very hard woods, and enable the screw to be driven or
inserted without the necessity for first boring a hole to receive it as the screw
is its own boring tool and makes its own hole as it is inserted..
The second part of this Invention has reference to the tools for cutting the
threads on the improved or other wood screws, and consists in the employment,
for that purpose of a cylindrical or other suitable curvilinear form of tool
whether a complete cylinder or only a segment of the same. This tool has a
series of parallel ribs or projections formed longitudinally upon its curved
surface, of a transverse section corresponding to the transverse outline of the
spaces between the threads to be cut on the screw. The cutting end of the
tool which may be made either tubular or solid is hollowed out or bevelled
inwards so as to leave sharp points at the extreme ends of the longitudinal
ribs, such points forming the chisels or cutting edges which remove the
superfluous metal from the screw blank in the operation of cutting the threads.
The peculiar cutting tool is mounted in an ordinary or suitable holder or
chuck, and as the screw blank revolves in contact with the cutting points the
latter remove the metal gradually from between several threads at the same
time by reason of the curvilinear form of the tool, and thus the work is
accomplished more rapidly and effectually than by the use of the ordinary
existing screw cutting tools. This tool may be sharpened when requisite by
simply deepening the bevelled hollow at the end of the tool.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on the
17th December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN HENRY
JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of June, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Henry Johnson, Her special license that I, the said John Henry

page_text: Johnson, my executors, administrators, and assigns, or such others as I, the
said John Henry Johnson, my executors, administrators, or assigns, should
at any time agree with, and no others from time to time and 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, the Channel Islands, and Isle of Man, an Invention for "Im-
PROVEMENTS IN WOOD SCREWS AND IN THE MEANS EMPLOYED IN THEIR MANUFACTURE,"
a communication to me from abroad by John Waldron Hoard and Solomon
Whipple Young, of Providence, in the State of Rhode Island, United States
of America, upon the condition (amongst others) that I, the said John
Henry Johnson, my executors or administrators, by an instrument in writing
under my hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, 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 John Henry Johnson, 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, reference being had to the accompanying Sheet
of Drawings and to the letters and figures marked thereon, that is to say:-
This Invention relates, firstly, to wood screws, and particularly to those
known as "gimlet pointed" screws, and consists in forming in the shank of
the screw one or more longitudinal grooves, flat sides, or indentations, which
extend upwards from the point of the screw and are transverse to the thread
of the same. By this means one or more cutting edges are produced in the
screw which by removing the wood materially assist the entrance of the screw,
more particularly in very hard woods and enable the screw to be driven or
inserted without the necessity for first boring a hole to receive it as the
screw is its own boring tool and makes its own hole as it is inserted.
The second part of this Invention has reference to the tools for cutting the
threads on the improved or other wood screws, and consists in the employment
for that purpose of a cylindrical or other suitable curvilinear form of tool
whether a complete cylinder or only a segment of the same. This tool has a
series of parallel ribs or projections formed longitudinally upon its curved
surface of a transverse section corresponding to the transverse outline of the
spaces between the threads to be cut on the screw. The cutting end of the
tool which may be made either tubular or solid, is hollowed out or bevelled
inwards so as to leave sharp points at the extreme ends of the longitudinal

page_text: ribs, such points forming the chisels or cutting edges which remove the.
superfluous metal from the screw blank in the operation of cutting the threads.
The peculiar cutting tool is mounted in an ordinary or suitable holder or
chuck, and as the screw. blank revolves in contact with the cutting points, the
latter remove the metal gradually from between several threads at the same
time by reason of the curvelinear form of the tool, and thus the work is
accomplished more rapidly and effectually than by the use of the ordinary
existing screw cutting tools. This tool may be sharpened when requisit: by
simply deepening the bevelled hollow at the end of the tool.
1:And in order that the said Invention may be fully understood I shall now
proceed. more particularly to describe the same, and for that purpose shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the Figures.
Figure 1 represents an elevation of a screw with grooves in its lower end
and Figure 2 is a transverse section of the same; Figure 3 is a similar section
of a modified form of the grooved end. The action of the ordinary. wood
screws when entering the wood is to jam the same away, or aside, its. small
end or point entering the wood first, being followed by the gradually swelling
shank which compresses the wood and forces it aside; this renders the
insertion of the screw into hard or close grained wood very difficult and
laborious, oftentimes causing the screw to be broken and subjecting the wood
to the liability of being split or cracked by the screw. To remedy these and
other defects I form the screw so that instead of compressing the wood it
shall cut its own way, dispensing with the use of gimlets or other tools to
bore the hole before the screw is inserted; extending upwards from the screw
point is a series of grooves f, Figures 1 and 2 the number of which may
vary, though I have found it best to adopt three as shown in the Drawing.
The course of the grooves, is transverse to that of the screw thread g and
consequently at the point where the latter is intersected by the grooves a
cutting edge c is formed, which materially aids the screw in its passage through
the wood. When the screw enters the wood the edges.c cut their way and
the screw gradually advances, not by compressing the wood but by cutting its
path, thus displacing the wood with: much greater ease than is the case with
the ordinary screw..
:
15
Figure 3 represents a modification by which the same effects to a certain
degree may be, produced as are accomplished by the grooves. The surface
of the screw instead of being grooved is ground flat, forming thereby cutting
edges c as before.
The second part of this. Invention relates to tools for threading screws, and

page_text: consists in the employment of a cutting tool of cylindrical or other suitable
curvilinear form which carries a series of longitudinal ribs terminating at one.
or both ends in cutting points or edges which constitute the means for forming
the thread in a screw blank. The tool is intended for use with ordinary or
suitable screw cutting machinery, and the advantages which result from its
employment are,-
First, the tool by reason of the arrangement of its cutters upon a circle or
are of a circle can cut the blank at two or more points at at once, and it thus
accomplishes in the same space of time more work than the ordinary cutting tool.
Second, the screw when completed presents a more perfect and neat
appearance than one cut by ordinary means by reason of the metal between
the threads being more gradually cut.
In the accompanying Drawings, Figures 4, 5, 6, 7, and 8 represent
different views of the screw cutting tool and the form of thread cut thereby.
Figure 5 is a longitudinal section of a cylindrical cutter, and Figure 6 is a
transverse section of the same. It will be understood, however, that the tool
may be simply a section or a segment of a cylinder, as shown in Figure 7, or
that it may have other suitable curvilinear form. Upon the surface of
the cylinder a, a series of longitudinal ribs 6 are formed, the distance between
as well as the shape of which may be varied to suit the form of and distance
between the threads desired; they may extend from one end of the cylinder
to the other, and in order to form cutting points or edges one of the ends of
the cylinder is recessed and the sides of the recess are bevelled as shown at s.
By this means the ends of the ribs b are cut away so as to form a series of
cutting points or edges d which project from the end of the cylinder as shown
in the Drawing. If the tool becomes dull it can readily be sharpened by
deepening the recess and bevelling its sides anew, so as to bring the cutters
again to a point or edge. The tool is mounted in an ordinary or other suitable
holder or chuck; the manner in which it operates being fully shown in
Figure 4. It will be seen on reference to Figure 4 that three or more cutters
are in contact with the blank at one time, so that as the latter is fed along, the
thread is cut with great rapidity.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that 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 is,-
First, constructing wood screws with cutting edges on their shanks transverse
to the thread thereof, as herein-before described and illustrated.

page_text: Second, the herein described improvements in screw cutting tools constructed
and operating substantially as described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Seventeenth day of December,
One thousand eight hundred and sixty-seven.
J. HENRY JOHNSON. (L.S.).