IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, AND IN MACHINERY OR APPARATUS TO BE EMPLOYED IN THE SAID MANUFACTURE
Year: 1874

page_text: LETTERS PATENT to George Hookham, of Birmingham, in the County
of Warwick, Manufacturer, for the Invention of "IMPROVEMENTS IN
THE MANUFACTURE OF SCREWS, AND IN MACHINERY OR APPARATUS TO BE
EMPLOYED IN THE SAID MANUFACTURE."
Sealed the 16th June 1874, and dated the 6th March 1874.
PROVISIONAL SPECIFICATION left by the said George Hookham at
the Office of the Commissioners of Patents, with his Petition, on
the 6th March 1874.
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I, GEORGE HOOKHAM, of Birmingham, in the County of Warwick,
Manufacturer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, AND IN MACHINERY OR
APPARATUS TO BE EMPLOYED IN THE SAID MANUFACTURE," to be as follows:-
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The object of my Invention is to cover the heads of iron screws with
a covering of brass of such a thickness and so applied as to permit of
the said brass covering being finished by the process of turning in a
lathe, and of receiving a nick similar to that made in the head of a solid
brass screw.

page_text: win describe my invention as applied to screws naying heads simular
to those of ordinary wood screws.
In carrying my Invention into effect I take iron screws having heads
smaller than usual, the said heads having broad shallow nicks in them.
I make a series of cylindrical brass caps by cutting out discs from sheet
brass, and raising them by dies and pressure into a cup-like form, the
size of the said caps being such that they fit loosely on the heads of the
iron screws. The said brass caps are of such depth that when their sides
are compressed, as herein-after explained, so as to fit tightly on the
conical under side of the head of the screw they cover or nearly cover
the whole of the said under side of the head:
.F
st
In order to effect the said compression and consequent fixing of the
brass cap on the head of the iron screw. I employ machinery or apparatus
constructed as follows:-The said machinery or apparatus consists
essentially of a pair of tools working in a press. The lower tool consists
of a die on the bed of the press having a hole in its axis. The diameter
of the lower, part of the hole is of a size proper to receive the stem of
the screw,
and the diameter of the upper part of the said hole is slightly
larger than that of the brass cap to be fixed on the head of the screw.
The upper and lower parts of the said hole in the die pass into one
another by a conical shoulder having the figure which it is desired to
give to the under side of the brass covering of the head of the screw. A
light coiled spring is placed at the bottom of the hole in the lower die.
To the screw or ram of the press a cylindrical tool is fixed of slightly
less diameter than the upper part of the hole in the lower die.
J
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3.Q
In using the said machinery or apparatus an iron screw with a brass
cap dropped or placed on its head is put into the fixed lower die, the
point end of the screw resting on the coiled spring described, so as to
support the screw with its head a short distance above the conical
shoulder described in the lower die. The upper tool descending the
screw and cap are carried down, and the said cap is compressed with
great force between the upper tool and the conical shoulder in the lower
die. By this compression the metal forming the mouth of the brass cap
is gathered in and compressed upon and fixed to the head of the screw,
and its outer surface fashioned to the required figure by the conical.
shoulder of the fixed die. The brass on the top of the head of the screw
is also forced into the nick. The upper tool may have on its acting-face.

page_text: a projecting rib crossing its centre, and the screw is so placed in the
lower die that the said rib shall be exactly over the nick in the head of
the iron screw.
This cross rib forces the brass cap into the nick in the
head, and by the mark it leaves on the said brass cap indicates where
the nick has to be made the the said cap. The head of the screw which
has thus been covered with brass is finished by turning and nicking in
the ordinary manner. It is necessary that the nick in the brass head
should descend into the nick in the iron head, so that on driving home
or withdrawing the said screw the screwdriver shall have the same hold
on the head as upon the head of an iron screw.
Although I prefer to apply a covering of brass to the heads of iron
screws in the manner described, yet a brass covering may be applied to
the heads of iron screws by casting. The heads applied by the casting
process are afterwards treated by dies and pressure, as herein-before
described.
Instead of compressing, fixing, and shaping the brass covering on the
head of the screw by means of a press, a stamp may be used with like
effect.
0
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Hookham in the Great Seal Patent Office
on the 1st September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HOOKHAM, of Birmingham, in the County of Warwick, Manufacturer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixth day of March, in the year of our Lord
One thousand eight hundred and seventy-four, in the thirty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and

page_text: grant unto me, the said George Hookham, Her special license that I, the
said George Hookham, my executors, administrators, and assigns, or such
others as I, the said George Hookham, 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 King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, AND
IN MACHINERY OR APPARATUS TO BE EMPLOYED IN THE SAID MANUFACTURE;” upon
the condition (amongst others) that I, the said George Hookham, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Scal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Hookham, 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, that is to say :-
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The object of my Invention is to cover the heads of iron screws with
a covering of brass or other metal, or alloy of such a thickness and so
applied as to permit of the said brass covering being finished by the
process of turning in a lathe and of receiving a nick similar to that
made in the head of a solid brass screw.
I will describe my Invention as applied to screws having heads.
similar to those of ordinary wood screws.
In carrying my Invention into effect I take iron screws having leads
smaller than usual, the said heads have large nicks in them. I make a
series of cylindrical brass caps by cutting out discs from sheet metal and
raising them by dies and pressure into a cup-like form, the size of the
said caps being such that they fit loosely on the heads of the iron screws.
The said brass caps arc of such depth that when their sides are com-
pressed as herein-after explained so as to fit tightly on the conical under
side of the head of the screw they cover or nearly cover the whole of
the said under side of the head.

page_text: In order to effect the said compression and consequent uxing of the
brass cap on the head of the iron screw I employ machinery or apparatus
constructed as follows:-The said machinery or apparatus consists
essentially of a pair of tools working in a press. The lower tool consists
of a die on the bed of the press having a hole in its axis. The diameter
of the lower part of the hole is of a size proper. to receive the stem of
the screw, and the diameter of the upper part of the said hole is slightly
larger than that of the brass cap to be fixed on the head of the screw.
The upper and lower parts of the said hole in the die pass into one
another by a conical shoulder having the figure which it is desired to
give to the under side of the brass covering of the head of the screw.
A light coiled spring is placed at the bottom of the hole in the lower
die. To the screw or ram of the press a cylindrical tool is fixed of
slightly less diameter than the upper part of the hole in the lower dic.
In using the said machinery or apparatus an iron screw with a brass
cap dropped or placed on its head is put into the fixed lower die, the
point end of the screw resting on the coiled spring described so as to
support the screw with its head a short distance above the conical
shoulder described in the lower die. The upper tool descending, the
screw and cap are carried down, and the said cap is compressed with
great force between the upper tool and the conical shoulder in the lower
die. By this compression the metal forming the mouth of the brass
cap is gathered in and compressed upon and fixed to the head of the
screw and its outer surface fashioned to the required figure by the
conical shoulder of the fixed die. The brass on the top of the head of
the screw is also forced into the nick. The upper tool may have on its
acting face a projecting rib crossing its centre, and the screw is so placed'
in the lower die that the said rib shall be exactly over the nick in the
head of the iron screw. This cross rib forces the brass cap into the nick
in the head, and by the mark it leaves on the said brass cap indicates
where the nick has to be made in the said cap. Or a depression may be
made in the cap before it is placed upon the head of the screw, in which
case the cross rib on the punch is not required. The head of the screw
which has thus been covered with brass is finished by turning and nick-
ing in the ordinary manner. It is necessary that the nick in the brass
head should descend into the nick in the iron head, so that on driving
home or withdrawing the said screw the screwdriver shall have the same
hold on the head as upon the head of an iron screw.

page_text: Although I prefer to apply a covering of brass to the heads of iron
screws in the manner described, yet a brass covering may be applied to
the heads of iron screws by casting. The head coverings applied by the
casting process are afterwards treated by dies and pressure as herein-
before described.
"PPY
screws in the manner described, yet a brass covering may be applied to
the heads of iron screws by casting. The head coverings applied by the
casting process are afterwards treated by dies and pressure as herein-
before described.
Instead of compressing, fixing, and shaping the brass.covering on the
head of the screw by means of a press a stamp may be used with like
effect.
The shanks of the screws may be protected from rust by galvanizing
or tinning, or other protecting process.
I will now describe, with reference to the accompanying Drawing,
the manner in which my Invention is to be performed.
"
I cut from sheet brass by means of a punch and lower die or tool a
blank or circular disc of the kind represented in Figure 1. By means
of a drawing-through process effected by drawing-through tools of the
ordinary kind the blank or disc, Figure 1, is shaped into a cap or shell
of the form represented in elevation and section in Figure 2. The sides
of the said shell or cap may be made slightly thinner than the closed
end of the cap. The cap, Figure 2, is next shaped by means of a pair of
press or stamp tools, herein-after described, so as to form nearly across
the inner side of the head or closed end of the cap a ridge or projection,
and on the outer side of the said head or end a V shaped notch or
depression for the purposes herein-after explained. The cap after it has
been subjected to the treatment last described, has the figure represented
in cross section and plan of upper side in Figure 3, the cross section
being taken at right angles to one another. In the said Figure 3 the
ridge or projection on the inner side of the head of the cap a is
marked b, and the notch or depression on the outer side of the said end
of the cap is marked c. The ridge or projection 6 fits in the nick in the
head of the screw and the notch or depression c serves as a guide for the
formation of the nick in the finished screw. By an examination of
Figure 3 it will be seen that the hollow or depression c does not extend
quite across the cap a, the metal at the edges of the said cap being left
nearly of the original shape.
The tools by which the fashioning of the ridge 6 and depression c is
effected are shown in section combined and in action in Figure 4, and
separately in Figure 5. In the said Figures 4 and 5, d is the lower tool

page_text: .
fixed on the bed of the press or stamp, and e is the punch or upper tool
fixed to the plunger or ram of the press or stamp. The acting end of
the punch e is cylindrical, the under side of the said acting end having
a cross groove e² in it. The hole in the lower tool d is cylindrical,
and the central peg f of the said lower tool has on its upper face an
angular projection g. The cap a, Figure 2, being placed with its closed
end downwards in the lower tool d and supported by the central peg f,
the punch or upper tool e is made to descend upon it. By the operation
of the said tools, as illustrated in Figure 4, the ridge 6 and notch or
hollow c are fashioned in the head of the cap. The brass cap, Figure 3, .
is now ready to be compressed, fixed, and shaped upon the head of the
screw which is to be covered. The said head of the screw has the form
represented in Figure 6, that is, it has a smaller head and the nick is
both deeper and broader than usual.
The tools by which the compressing, fixing, and shaping of the brass
cap, Figure 3, upon the head of the screw are effected, are represented
in Figures 7, 8, and 9. Figure 7 representing the said tools in vertical
section, and exhibiting the positions of the parts before the descent
of the punch or upper tool, Figure 8 representing the same after
the punch has descended and closed or compressed, fixed, and shaped
the brass cap upon the head of the screw, and Figure 9 representing
the lower tool separately. The punch or upper tool which is attached
to the plunger of the press or stamp is marked h, and the lower tool
which is fixed on the bed of the press or stamp is marked i. In the
lower tool is an axial hole, the upper and lower parts 7, k, of which
are of different diameters, the lower part k having a size proper to
receive the stem of the screw which loosely fits it, and the upper
part having a size proper to receive the shaped cap, Figure 3, and
the punch h. The upper and lower parts l, k, of the axial hole in the
lower tool i pass into one another by a conical shoulder m having the
same inclination as the sides of the head of the screw to be covered,
but of greater depth, as represented. The upper tool or punch / is
cylindrical, and fits accurately the upper cylindrical hole in the lower
tool. At the bottom of the cylindrical hole k is a spring seat or support
on which the point of the screw n is supported when placed in the lower
tool.
In using the tools, Figures 7, 8, and 9, the screw n, Figure 6, is
land and sunnanted in the lawan dia i as that its band is above the

page_text: conical shoulder m. The shaped cap a, Figure 3, is next placed mouth
downwards in the lower die, the ridge of the said cap being fitted
into the nick n² in the head of the screw, as represented in Figure 7.
The parts having the relative positions represented in the said Figure 7
the cylindrical punch is made to descend and enter the lower tool i.
By the operation of the said punch the screw n and cap a are carried
down, and the said cap is compressed with great force between the
punch and the conical shoulder m of the lower die or tool i, the
metal at the mouth of the cap being gathered in and compressed upon
and fixed to the conical under side of the head of the screw, while the
closed end of the cap is compressed upon the top of the head of the
and the ridge forced' into and made nearly to fill up the nick n²
in the said head, as illustrated in Figure 8. The head of the screw is
thus covered with a covering of brass, and the said covering is ready
to be finished by being turned and nicked. In effecting the nicking
of the covered brass head care must be taken that the nick cut in the
said brass covering is symmetrical with the nick in the head of the iron.
the notch or hollow c left in the brass covering serving as a guide
for accurately nicking the said brass covering.
screw,
screw,
Figure 10 represents partly in section a finished scrow, the head of
which has been covered with brass, and the head turned and nicked as
before described.
When the shanks of the screws are to be protected by galvanizing or
tinning or other protecting process the galvanizing or tinning process is
performed after the headed screw is pointed and wormed, and before its
head is nicked and turned, the zinc or tin being removed from the head
by the turning process. The screw may be pointed, wormed, and
galvanized before the brass cap is fixed on the head.
In order to facilitate the placing of the screw or screw blank, Figure 6,
and brass cap, Figure 3, in the lower die or tool i the ridge b in the said
cap may be made to fit tightly in the nick n² in the screw blank. The
cap is then driven on the head by a hammer; it is thereby held with
sufficient firmness in the proper position until fixed by the pressure of
the descending punch h.
As the cylindrical part of the cap on being fixed on the screw head is
shortened and thickened I make the cylindrical part longer and thinner
than the finished brass covering of the under side of the screw head.

page_text: Although I prefer to provide the cap, Figure 2, with a ridge b and
hollow c, as represented in Figure 3, before the said cap is placed upon
the head of the screw to be covered, yet a cap of the shape represented
in Figure 2 may be employed in place of the said cap, Figure 3. In this
case I provide the acting end or face of the punch with a cross.
projecting rib, and the nick n² in the screw, Figure 6, is so placed in
the die i that it is exactly under the rib described on the punch 7.
By the descent of the punch its cross rib forces the brass cap into the
nick of the screw head, and also leaves a line or mark on the cap where
the nick has subsequently to be made in the said cap.
:
Instead of employing a sheet metal cap as before described a brass
covering may be cast upon the head of the screw, and the covered head
be afterwards operated upon by means of the tools, Figures 7, 8, and 9,
for the purpose of compressing and moro firmly fixing the cast covering
upon the head and perfecting the general figure of the said covering.
The cast covering fixed upon the head of the screw is finished by
turning and nicking, as described with respect to a sheet brass cap or
covering.
Instead of a covering of brass a covering of copper or other ductile
metal or alloy may be employed.
The tools hercin-before described and illustrated in the accompanying
Drawing may be worked in presses or stamps of the ordinary kind, or
the said tools may be worked in special machines made for the purpose,
or such as are commonly used for shaping or fashioning metals.
The heads of all kinds of countersunk screws as well as screws having
hemispherical or other shaped heads may be covered with brass according
to my Invention.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood
that I do not limit myself to the precise details herein described and
illustrated, as the same may be varied without departing from the nature
of my Invention; but I claim as my Invention of improvements in the
manufacture of screws and in machinery or apparatus to be employed in
the said manufacture,―
First. Covering the heads of iron screws with a covering of brass or
other ductile metal or alloy, substantially in the manner herein-before

page_text: described and illustrated in the accompanying Drawing, that is to say,
preparing the head of the screw to be covered in the manner described,
placing upon the said head a sheet metal cap or covering or casting, a
metal cap or covering upon it, and compressing, fixing, and shaping the
said metal cap upon the said head, substantially as described and
illustrated, whereby the head of the screw is covered with a covering of
brass or other ductile metal or alloy of such a thickness and so applied
thereto as to permit of the said brass or other covering being finished by
the process of turning in a lathe, and of receiving a nick similar to that
made in the head of a solid metal screw.
Secondly. The tools or apparatus herein-before described and illustrated
in Figures 4, 5, 7, 8, and 9 of the accompanying Drawing to be used in
fashioning the brass or other metallic cap, and for compressing, fixing,
and shaping the brass or other cap or covering upon the head of the
screw.
In witness whereof, I, the said George Hookham, have hereunto
set my hand and seal, this Twenty-fifth day of August, in the
year of our Lord One thousand eight hundred and seventy-
four.
Witness,
GEORGE SHAW.
GEORGE HOOKHAM. (L.S.)