Improvements in and relating to Screws and Bolts.
Year: 1896

page_text: Date of Application, 14th Mar., 1896-Accepted, 2nd May, 1896
COMPLETE SPECIFICATION.
Improvements in and relating to Screws and Bolts.
We, HENRY PATTERSON BOYD, and PETER BURT, trading as Henry P.
Boyd & Co. at Baltic Chambers, Quayside, Newcastle-on-Tyne, in the County
of Northumberland, Engineers do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Our invention relates to improvements in the forging or hammering of screws
and bolts for metal or wood work or both, and in the uses to which such screws or
bolts constructed according to our invention, may be applied, our said invention
having for its objects, cheapness of manufacture, and added strength by reason of
the molecules of the metal being more intimately connected with each other, than
obtains when such screws or bolts are cast as hitherto.
For the purposes of our invention, we employ in pairs, any number of steel tools
or dies, cast or otherwise, each pair being so formed as to impart a certain
formation to a heated blank, such for instance as forming a point upon the leading
end of same, while the next or subsequent dies may form a wood or metal thread
thereon, of any desired pitch or pitches. Or we may so construct the said dies or
tools that one pair of these may perform both operations simultaneously and
produce the finished screw or bolt.
We may employ any machine or apparatus for operating the said tools or dies,
but we prefer to use a steam hammer, having in the under face of the hammer
bead, suitable dovetail or other recesses for the reception of like shaped keys or
extensions upon the top surface of the upper dic, while extensions upon the under
surface of the lower die, engage with like shaped holes or recesses in the base of
the hammer.
In order that our invention and the manner in which we purpose operating the
same, and the uses to which screws or bolts so constructed may be employed, may
be fully understood, we have hereunto appended two sheets of drawings of
which:-
Fig. 1, Sheet 1 is a plan view of one of a pair of dies, say the lower one, as we
prefer to construct them for forming a point upon the heated blank as hereinafter
explained, Fig. 2 being a section of same upon the line A B.
Fig. 3 is an elevation of a pair of such dies, as these would appear when placed
face to face and viewed upwardly of Fig. 1.
Fig. 4 is a plan view of the lower one of a pair of such dies employed for
forming a right handed screw thread upon the re-heated blank after treatment by
Fig. 1.
Fig. 5 is a plan view of the lower one of a pair of dies, constructed to form a
point and right handed screw thread upon the blank in one operation.
Fig. 6 represents such a blank before treatment, while Fig. 7 represents the
same after treatment by a pair of dies such as Fig. 2, and Fig. 8 shews the same
blank after treatment by a pair of dies such as Fig. 4 or Fig. 5.
Figs. 9 and 10 are views of forged screws or bolts illustrating two out of an
endless variety of forms in which, according to our invention, these may be made by
the employment of dies of the necessary formation, a further variety of such screws
or bolts, and some of the uses for which these may be employed, being illustrated by
Figs. 11, 12, and 13, Sheet 2.
We carry our invention into effect by casting or otherwise producing of chilled
iron or steel, preferably the latter, a pair of dies A of any size desired, and which

page_text: for clearness of description we will presume is to be employed for producing a
point upon the blank B Fig. 6. In each of these dies we form a recess C, tapered
at one end substantially as at Fig. 1, the diameter of the said recess at the face of
the die being slightly in excess of the cross sectional diameter of the blank B, and
in cross sectional formation slightly less than a true semicircle, that is to say, when
the dies are placed face to face and parted the distance of an eighth of an inch or
thereabouts, the two recesses in cross section would form a true circle as shewn by
Fig. 2, the object of this being, that the blow imparted by the meeting of the two
dies may be upon the upper and lower faces of the blank placed between them,
which permits the blank to be more easily rotated or otherwise manipulated
between each blow, without being jammed between the dies, as would be likely to
occur if the recesses C were each a true semicircle in cross section, and of a
diameter equal to that of the blank B..
As previously stated, we prefer to employ a steam hammer for operating these,
and for this purpose we provide upon the top of the upper die two or more dovetail
or other shaped key-projections a, and like shaped recesses in the under surface of
the head of the hammer into which these may slide, while the under face of the
lower die may have parallel or other shaped projections such as b, which may fit
into like shaped recesses in the base of the hammer, screws, pins, cotters or the like
being employed for retaining them in place, and in such position, that the upper die
may register truly with the lower die at each stroke of the hammer.
We purpose constructing our said screws or bolts of any and every kind of
metal or alloy of metals, suitable for the purpose, of which we first produce a blank
such as B, which we may effect by casting or by forging, or if desired by the use of
suitable dies, and this when heated would be held by the head by suitable tongs or
other tools, and the shank thereof be laid in the groove C in the lower die A and
by a forward pressure, and partial rotation of this between each stroke of the
hammer or meeting of the dies, a point e may be formed thereon as at Fig. 7,
the angle and length of which will depend upon the angle and length of the tapered
end of C. At the completion of the pointing operation a pair of dies D such as
Fig. 4 may be employed, placed upon and connected to the hammer in like manner,
each of which have a like but parallel recess C, in which are formed helical
recesses d, the pitch and cross sectional formation of the latter, being such as to
produce upon the blank, the screw thread desired, which for example we will
presume to be a wood thread of the pitch shewn. The pointed blank Fig. 7 being
again heated would be operated upon in like manner by the dies D, ultimately
producing a screw or bolt with a perfect thread e, substantially as at Fig. 8, which
may be of any desired length, irrespective of the width of the dies D, as by rotating
the blank the gradual formation of the thread thereon would lead or feed the
blank forward until a thread was formed upon the whole length, or any desired
portion thereof.
We may find it convenient to sometimes use dies in which two recesses C are
formed, parallel with each other one, say like that in Fig. 1, and the other say,
like that in Fig. 4 or substantially so, so that the heated blank when pointed by
the use of the first, may be transferred to the second for the forging of the thread,
this arrangement in some cases saving the re-heating of the blank.
Or we may use dies E constructed substantially as at Fig. 5, having a pointed or
taper ended recess C, and helical recesses d, or in other words, being a combination
of Figs. 1 and 4, the forward movement of the blank, as the thread is formed
thereon, providing the necessary forward pressure for tapering or pointing the end.
The heads of the said screws or bolts may be of any desired formation most
convenient, according to the uses for which they are intended, such for instance as
at Fig. 8, so as to be operated by a screw driver, or as at Fig. 9 shaped to receive
a spanner, or as at Fig. 10 adapted to receive a key or adjustable spanner.
We
may also find it convenient to form the head of the screw or bolt similar to a
truncated cone, the outer surface of which may be plain as at Fig. 10, or longer
and curved as at Fig. 11, or shorter and stouter as at Fig. 13.

page_text: From the foregoing it will be understood, that by the employment of dies, or a
series of dies of suitable formation as regards the portions C and d, we are enabled
to forge pointed scrows and bolts of any size, of any metal or alloy of metals, with
threads of any pitch or various pitches, and either suitable for wood work only as
at Fig. 8, or with right and left handed, square or other shaped threads as at
Fig. 9, suitable for wood or metal, or a screw or bolt of two diameters with a wood
and metal thread both of the same pitch as at Fig. 10, or a right handed wood
thread and a left handed metal thread as at Fig. 11 or any desired combination
of threads suitable for any and every purpose for which screws and bolts are or
may be required, amongst the many of which may be mentioned the fixation of the
metal facings of steam boat piers and waterside wharves, dock and lock gates and
other places, where metal and wood have to be screwed or bolted together, more
particularly the fixation of armour plates upon vessels of war.
In the case of armour plated war vessels, it has hitherto been customary to fix
such plates upon the teak body of the vessel by first boring a hole through the
wood portion and passing long bolts loosely and outwardly through these, each
having a threaded portion passing through holes in the armour plate, which then
receive suitable nuts outside the plate, or in some cases headed screw bolts are first
passed inwardly through holes in the armour plates and then through holes bored
in the wooden body of the vessel, these being ultimately tightened by nuts upon the
inside, but in no case, so far as we are aware, have bolts ever been used capable of
and being screwed into the wooden portion of the vessel, and it not infrequently
occurs when a ship is in action that not only do such plates become punctured,
perforated or partly carried away, but in many cases, the bolts that hold them get
broken or cut in two, and the outer portion carried away with them, with the
result, that should such bolt be below the water level, the wood through which
the remainder of the bolt loosely passes would form an easy passage or inlet for the
water, to the detriment of the safety of the vessel. In Figs. 11, 12 and 13 we
illustrate how our improved forged screws or bolts may be constructed and
employed for such and analogous purposes, and obviate such contingencies.
Fig. 11 is a section of the shell of an armour plated vessel, in which G is the
armour plate and H the wooden body of the vessel. This arrangement shows
the employment of one of our forged taper-ended bolts, having a long curved,
taper-head formed as at 9 for the reception of a key or adjustable spanner or
screw hammer, and provided with a wood thread and left handed metal thread e',
and a hole suitable for the reception off would be made in the armour plate G, and
the leading or pointed end of the bolt or screw B having been passed inwardly
through this would be screwed through the wood work H, the formation of the
bend serving to draw the plate G in close contact with H as B is screwed home,
the opposite or free end of this ultimately receiving an angle iron or other plate J,
and nut K.
Fig. 12 which is a similar section of a vessel illustrates the employment of a
screw bolt having a head f similar to Fig. 8, a wood thread e for about half its
length and a left handed metal thread at its initial end. According to this
arrangement the screw bolt B would be first screwed into and through the wood
portion H, and then through a hole in the plate G, in which provision is made
for the reception of a suitable spanner for screwing home a nut K upon the
thread e¹.
Fig. 13 which is a like section, illustrates the employment of a bolt similar to
Fig. 10. In this arrangement the inner surface of the plate G is bored and
threaded to receive the metal thread el of the bolt, while the wood portion H
receives the wood thread e, the bolt being screwed into both H and G from the
inner side of the vessel, and by this means the manner of fixing the plate is invisible
from outside the vessel.
In either of the foregoing methods of fixing armour plates upon war vessels, the
bolt or screw B, is screwed and cuts its way into and through the wooden
portion H of the vessel, and fits its self-made passage perfectly, water tight, so that

page_text: should the plate & be punctured or fractured, and the portion of the bolt passing
therethrough be carried away, no water could possibly enter through the bolt
passage in the wood H, and by reason of the bolts being produced by forging, the
metal would be obviously tougher, and calculated to bear a very heavy bending
strain before breaking.
The views Figs. 1), 12 and 13, will also serve to make clear the manner in which we
employ our improved bolts or screws in all cases where metal and wood has to be
firmly connected together.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
First. The manufacture of pointed or other screws and bolts of any metal or
alloy of metals, by forging or hammering, and the use of suitable dies or tools in
the production of same, and the use and application of screws or bolts so made for
all purposes for which screws and bolts are used, especially in the fixation of
armour plates upon war vessels, and for other purposes analagous thereto,
substantially as, and for attaining the objects herein described, and shewn by the
appended drawings.
Second. In the forging of pointed acrews and bolts of any metal or alloy of
metals, the construction and employment of steel or other dies A, each having a
recess or groove C, pointed or graduated at one end, and of slightly larger
diameter, and greater radius in cross section than the heated blank B Fig. 6 to be
operated upon, and pointed thereby, with means, such as a and b, for fixing such
dies in connection with a steam or other hammer substantially as herein described
and shewn by Figs. 1, 2 and 3 of the accompanying drawings.
Third. In the forging of pointed and other screws and bolts, the construction and
use of steel or other dies such as A, each having a recess or groove C, of greater
radius in cross section than the heated pointed blank B Fig. 7, and in which is
provided helical recesses d for forming a right or left handed wood or metal thread.
or threads or right and left handed wood and metal threads upon the said blank,
such for instance as at Fig. 8, with means such as a and b for fixing such dies in
connection with a steam or other hammer, substantially as herein described aud
shewn by Fig. 4 of the accompanying drawings.
Fourth. In the forging of pointed screws and bolts, the construction and use of
steel or other dies such as A, each having a recess or groove C, pointed or
graduated at one end, and of slightly larger diameter and greater radius in cross
section than the heated blank B Fig. 6 to be operated upon thereby, with helical
recesses d formed in C, for pointing the end of the blank B and forming a right or
left handed wood or metal thread thereon in one operation, such for instance as
Fig. 8, with means such as a, b, for connecting the said dies to a steam or other
hammer, substantially as herein described, and shewn by Fig. 5 of the accompany-
ing drawings.
Fifth. In the forging of pointed or other screws or bolts of more than one
diameter in cross section, the employment of suitable dies as set forth in the
preceding claims, in any order of nse, for forming a right or left handed wood or
metal thread upon both diameters, or a right handed thread upon the one diameter,
and a left handed thread upon the other, or a wood thread upon the one diameter and
metal thread upon the other, examples of which are shewn in Figs. 9, 10, 11, 12
and 13, substantially as and for the purposes herein described and shewn.
Sixth. In the forging of screws and bolts as set forth in the preceding claims,
the employment of suitable dies or swaging tools in combination with a steam or
other power hammer substantially as berein described and shown.
Seventh. The employment of forged screws or bolts, as set forth in the preceding
claims, in the fixation of metal upon wood, such as in the construction of dock and
lock gates, floating and other piers or wharves, and in the fixation of armour
plates upon war vessels, in which the said bolts are screwed into the wood portion,

page_text: and bolted to, or screwed into the metal portion, substantially as and for the
purposes herein described, examples or specimens of which are shewn by Figs. 11,.
12, and 13 of the accompanying drawings.
Dated this 14th day of March 1806
GEO. THOS. HYDE,
1, Broad Street Buildings, Liverpool Street, London, E.C.,
Agent for Applicants.