IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF SCREWS, BOLTS, AND NUTS
Year: 1859

page_text: LETTERS PATENT to Frederick Allen Leigh, of the City of Manchester,
in the County of Lancaster, Mechanical Engineer, for the Invention of
"IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF
SCREWS, BOLTS, AND NUTS."-A communication from abroad by Richard
PROVISIONAL SPECIFICATION left by the said Frederick Allen Leigh at
the Office of the Commissioners of Patents, with his Petition on
the 15th October 1859.
I, FREDERICK ALLEN LEIGH, of the City of Manchester, in the County of
Lancaster, Mechanical Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANU-
FACTURE OF SCREWS, BOLTS, AND NUTS," a communication from abroad by
Richard Hartmann, of Chemnitz, in the Kingdom of Saxony, to be as
follows:-
The screws from the forging machinery are centered and then turned in a
duplex sliding lathe, after which the hexagon heads are shaped in an improved
shaping machine. The bolt of the intended screw is placed in an elastic tube
or socket with a tapered head on the exterior, which taper fits a corresponding

page_text: part of another tube furnished with a dividing plate, and capable of turning
in a table working on a slide. The elastic socket is bored at its fore
part of the diameter of the screw, and holds the latter firm when the taper
part of the socket is drawn by a screw and nut into the taper part of the
tube which supports it, a pin or catch being employed to enable both tubes to
turn together. The elastic tube or socket is provided with a six-sided head
a little smaller than the required shape of the head of the screw, for the
purpose of regulating the position of the cutting tool, and also the position of
the screw head against the dividing plate. When the screw is fixed, one side
of the head is shaped by sliding the table, then the catch is turned so as to
move the dividing plate and the next division of the head is shaped, and so on,
until all are finished, when the elastic tube or socket is loosened from its holder,
and another bolt supplied for a fresh operation. When the heads are shaped
the bolts are screwed in a screw-cutting lathe especially adapted for the
purpose.
The aforesaid machine is also employed for shaping the sides of hexagon
nuts by screwing them on to a bolt placed in the elastic socket and afterwards
acting in the same manner as with the heads of the screws. Instead of
turning the faces of the nuts as at present they are shaped in a machine
having an ordinary lathe headstock in the arbor of which the nuts are placed,
the cutting tool being fixed to a holder which slides in a frame attached to the
sliding puppet of the loose headstock. The tool is ground on one side upwards
and the other side downwards, one side cutting the straight part of the nut
and the other the chamfer or fluting, set screws being employed for regu-
lating the required diameter of the face and also the height or depth of the
nut. By the application of a suitable chuck, this machine is adapted for
shaping the faces of screws or bolts, it being understood that the parts are of
various dimensions according to the work required; I also turn the sides of a
number of nuts at one operation by employing a duplex lathe having two
headstocks, two slide rests, and two face plates one adapted for small and the
other for large nuts. The face plates are furnished with two sets of blocks for
supporting the screws or bolts to which are attached the nuts to be turned,
one set being for dividing and the other for fixing and removing the bolts,
each of the latter having a head of the same form as the nuts are to be turned
or shaped. When one side is finished the bolts have to be turned a division,
screws and handles being employed to slacken and tighten the required parts.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Allen Leigh in the Great Seal Patent Office on
the 14th April 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
ALLEN LEIGH, of the City of Manchester, in the County of Lancaster,
Mechanical Engineor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of October, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Frederick Allen Leigh, Her special licence that I, the said
Frederick Allen Leigh, my executors, administrators, and assigns, or such
others, as I, the said Froderick Allen Leigh, 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, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANU-
FACTURE OF SCREWS, BOLTS, AND Nurs," a communication from abroad by
Richard Hartmann, of Chemnitz, in the Kingdom of Saxony, upon the condition
(amongst others) that I, the said Frederick Allen Leigh, 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
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 Frederick Allen Leigh, do hereby
declare the nature of the said Invention, and the manner in which the same
is to be performed, to be particularly described and ascertained in and by
the following statement thereof, reference being had to the accompanying
eleven Sheets of Drawings, and to the figures and letters marked thereon (that
is to say):
The intended screws or bolts forged on the forging machine are centered,
and then turned on a self-acting duplex sliding lathe, after which the hexagon
heads are shaped in the machines shewn at Figs. 1, 2, 3, and 4, which are
only annexed for the purpose of illustrating the course of work. Figs. 5 and 6
are detailed Drawings, in full size, of the apparatus for fixing and dividing.the
bolt heads, and Figs. 7, 8, 9, and 10 are views of detached parts, which are

page_text: also employed for the shaping of nuts. Figs. 11 and 12 are full size Drawings
of a similar apparatus adapted for larger bolt heads, Figs. 13, 14, 15, and 16
being also views of detached parts intended for larger bolt heads and nuts.
The apparatus for fixing and dividing the bolt heads consists of a cast-iron
bearing A, which is fixed on the table of the shaping machine in its required
position. In the bearing A the box B is fitted, so as to be capable of turning
with case and steadiness, and on it is fixed the dividing plate C, which is held,
as desired, by the catch D. On the box B is fitted the elastic tube or box E,
which is for the purpose of holding the body of the bolt, the box for the larger
bolts and nuts being shewn at Figs. 7 and 8, and the smaller ones at Figs. 9
and 10. The said boxes are bored at the forepart of the diameter of the body
of the bolt, but at the other part larger, in order to prevent the bolts from
touching the circumference, and to facilitate the elasticity of the boxes. Each
box E has four mortices, which are partially closed or drawn in when its
conical part at the top is forced into the conical part of the box B by the
nut F, thus pressing the bolt, and keeping it in fixed communication with the
box E. The pin G prevents the box E from turning in the box B, and
the hexagon head H, which is a little smaller than the required head of the
bolt, is for the purpose o regulating the position of the tool, and also the
position of the head of the bolt as regards the dividing plate. When the bolt
is properly fixed, one side is shaped by sliding the table of the machine in a
corresponding direction; then the catch D is lifted out without stopping the
machine, and the dividing plate C is turned by the nut F to the next division,
and the head is then in the right position for shaping the second side, the table
being moved as required, and so on, until all the sides are shaped, and then
the nut F is loosened, so that the bolt may be taken out of the box, and a
fresh operation commenced. When the heads are shaped, the bolts are
screwed in a screw-cutting lathe, especially adapted for the purpose. The
aforesaid shaping machines are employed for shaping nuts, as will be explained
hereafter. The threads or screws of the nuts are formed in the ordinary nut-
screwing machines, but the other operations are performed by new methods.
Instead of turning the faces of the nuts, they are shaped with a cutter in the
apparatus shewn in Figs. 17 and 18, drawn to about half size. There is an
ordinary lathe headstock, on the arbor of which the nuts are placed. The
arbor of the sliding puppet has a head A, in which slides the tool holder B,
which is adjusted by the screw C. In the tool-holder B is the tool D,
which is ground on one side upwards and on the other side downwards, so
that two sides can be cutting. One side is for forming the straight part of
the nut, and the other side the inclination, chamfer, or fluting. When the

page_text: position of the tool D is regulated by the screw C, for obtaining the right
diameter of the straight face, the machine works and shapes the nut, by
causing the tool to advanco towards the nut. The set screw E, which joins
the face plate, is for obtaining the thickness of the nuts; the same machine
is also for shaping heads of bolts or screws to any desired pattern, and then
the face plate must be changed with a suitable check, the machine being made
of different dimensions according to the sizes of the bolts, screws, or nuts.
The following and last operation for making nuts is shaping the sides, which
for small nuts is performed in the shaping machine, Figs. 1 and 2, with the
apparatus shewn in Figs. 5, 6, 7, 8, 9, and 10, and for large nuts, in a lathe
constructed expressly for the purpose. When the nuts are shaped in the
shaping machine, bolts T, of the required size, are put in the box E, Fig. 8.
On the forepart of T the nuts are screwed; and the lever K is for the purpose
of bringing down and uniting the bolt and nut to the top H of the box E,
and to obtain the right position for shaping the hexagonal side of the nut;
the operations of shaping being similar to those for bolt or screw heads.
In order to turn or shape the sides of a larger number of nuts at one operation,
I employ a duplex lathe, shewn in Fig. 19, having two headstocks and two
slide rests, one being for large nuts, and the other for smaller ones. The
chief parts of this machine are the face plates, one of which is represented
in Figs. 20 and 21, of which detached parts are shewn in Figs. 22, 23, 24,
and 25. The six steel bolts A are for holding the nuts, and have near one
end a hexagon head a, of the form and size the nuts are required to be made.
On the part 6 (which is of the same diameter as the interiors of the screwed
The
or tapped nuts) the said nuts are placed concentric with the head a.
nut c, which is a little smaller than the head a, holds the nuts to be turned or
shaped firmly in their places, and the bolts A are supported by their end
bearings d and d¹. At d' there is a bush, when the dimensions of the bolts
allow it. These bearings d and d' are supported in the six blocks B and C,
of which the first is for dividing, and the second for taking in and out the
bolts. The centres of the said blocks B and C are of sixty degrees radii; in
order to obtain an equal length for all the bolts. In order to remove the
bolts A, and also to fix them in their proper places, the blocks C. are drawn
in and out by the screws H, until the bearings d and d' are in their right
position, after which the screws are reversed in their action until' the bolts are
in their right position; and when the said bolts are moved, in. order to expose
another face of the nuts, the block C must be slightly drawn back, and when
they are again returned to their places, the set nuts T are fastened, so that no
pressure will be on the screws H. The blocks B are fixed by the nuts D, and

page_text: have on the ends of the screws the nuts E. In moving backwards and
forwards, the nuts E take with them the frames F, and consequently the
pins G, which pins have flat heads sliding on the side faces of the blocks B,
and are prevented from turning. When the bolts A are in their places, the
pins G are advanced until they touch the inner faces of the heads a, and by
that means the said inner faces and also all the concentric fixed nuts are
parallel with the face plate, and consequently with the axes of the bolts A,
because all the bearings have an equal distance, therefore if the faces of the
nuts of the bolts A are turned, they are all equidistant from the axes or
centres of the nuts.
In Figs. 26, 27, 28, 29, 30, 31, and 32 I shew another arrangement for
turning the end faces and forming the edges of the heads of screws, bolts, and
nuts. The Figures are drawn to about half size, and the object of the
machine is to improve the turning of the surfaces of the said screw heads,
and to render the tools more lasting, better acting, and more easily repaired,
and also to increase the productive effect of the machine. These objects are
attained by means of an elastic holding apparatus, by using ordinary turning
tools, and by the arrangement and self-acting motions of the machine. In
the headstock there is a hollow mandril or spindle A, which receives rotary
motion by means of a cone pulley and toothed gearing. The front end of the
spindle is furnished with a split socket or elastic holder, it being bored out
for this purpose at A, and has at a¹ an internal thread or screw.
The spindle
is bored out to receive the elastic socket B, and thereby maintains it perfectly
central. The said socket is bored in front, of the diameter of the largest
screw intended for the machine, and at the back a little larger, in order to
allow the free action of the spring obtained by the splits in the socket. The
nut C, which at c is squared for the key, is bored out according to the cone B,
and is fitted into the front cylindrical part of A, thereby keeping it central.
If the screw be put in the socket B, and the nut C screwed up, then the
conical part at B will be pressed together, and the screw will be fast and
central by means of the splits in the socket B, which is centered in A, as well
as the nut C, which presses inwards to the conical part of B. The spindle A
is hollow for long screws, and has at a² six indentations or notches, into which
the latch D can be placed, so that when the nut C is turned, the spindle shall
not move. For smaller screws, either split cylindrical sockets are placed in
the front part B, or similar pieces or sockets at B are made internally of the
dimensions to suit the screws.
For turning the faces and edges of nuts I employ the screwed pin or
bolt E, Fig. 28, which is fitted into the elastic holder B, and has in front the

page_text: screw on which the nut is placed. The turning tools are shewn at F and F¹;
the first turns upon the plain even surface, and the second turns the chamfer,
round, or groove of any desired pattern. The tools are fastened to the tool
holder G, which moves upon the stud H upon the transverse slide I. The
lever K has a latch k, which is pressed by a spring into a notch, so that the
tool holder G may always be in its right position.
When the screw or bolt is to be put in or taken out of the socket, the
lever K is raised, so that the latch may come out of the notch; then the
tool holder G is turned by the lever K until the screw or bolt by passing
the two tools can be put in or taken out; then, the tool holder G is returned
to its original position. The screw L is for the purpose of sliding backwards
and forwards the transverse slide I, together with the tool holder G, according
to the required diameter of the face of the head to be turned. The slide M
is pressed forwards by the screw N towards the face of the head, and thereby
turns it. The adjustable screw O is for a stop to the slide M, so as to
regulate the exact depth or thickness of the nuts or bolt heads. The screw N
receives its self-acting motion from the ratchet or toothed wheel P, which is
moved by the ratchet or catch on the lever Q, which receives its oscillating
movement by connecting it by a rod to the lever R, upon the shaft or spindle
of which at the end of the headstock is the lever T, attached at the top to the
rod U, connected at the end to a crank V, the boss of which is screwed upon
the hollow mandril A. The lever T is formed with a fork or joint at the top,
into which is fitted the slotted end of the rod U, in the slot of which works
the guiding piece W, kept in its place by the joint and pin X. In the
piece W is attached one end of the pin y, its other end working through a
hole in the end of the rod U. Around the pin y is placed the spring Z
which presses the picce W to the upper end of the slot, and is strong enough
by the motion of the crank to move the levers and ratchet wheel, and thus to
set on the self-acting movement of the machine. But when the nut or bolt
head is turned to its proper depth, and the slide M comes in contact with the
head of tho regulating screw O, then the levers become stationary, and the
slot of the connecting rod U slides over the guiding piece W, the spiral
spring yielding to the pressure. Without this or similar arrangement, the
machine would either be stopped or some breakage might take place.
In Figs. 33, 34, 35, 36, 37, 38, 39, and 40, I shew another arrangement
of machinery for shaping tho sides of the nuts and bolt heads. The machine
acts vertically instead of horizontally, and is formed double. Each side has
two cutting tools or chisels for shaping two sides of each nut or head at one
operation at each sido of the machine. Upon the left side is shewn the

page_text: pin k, so that the tools in
The tools are fastened with
elastic holder suitable for ordinary bolts or nuts, and on the other side an
arrangement of slides adapted for shaping bolts and nuts of irregular forms,
such as couplings of cylinders, screws with long square heads, or similar
articles. In the machine is the spindle A, put in motion the cone pulley B,
which spindle has on both ends the crank C; the bosses carrying the crank
pins D have slots for regulating the length of stroke. Each crank pin is
formed with a screw and nuts, and is furnished with a friction roller or socket,
on which works one end of the connecting rod E, the other end being con-
nected to the pin F, fixed to the slide G, and gives it motion; the slide G
works vertically in guides, and has a slot in which the pin F is adjusted, so
that the traverse of the tools may be regulated as required. At the lower
part of the slide G are the transverse slides 9 upon which the frames or
blocks H work; they are shifted by the screw I, the handle for which is on
the right side. When the screw I is put in motion, the blocks H can
approach to or separate from each other with equal facility. The parts K
turn in the blocks II in order that the tools may be adjusted for the right cut,
and when this is done, the screw his fastened. At the lower part of K are
the tool holders L, fitted to and turning upon the
their backward movement shall not be injured.
the screw L and the wedge in the holders L. The elastic holder is fastened
to the upper slide M, and by the screw N it can be shifted transversely in the
lower slide O; this is required to adjust the elastic holder, so that the two
tools may work equidistant in the middle of the nuts or bolt heads. The
lower slide O is put in self-acting motion by the screw P. The self-acting
motion of the screw P is obtained by means of the ratchet wheel Q and lever
and ratchet R, which are connected by the rod S to the lever T. Upon the
shaft of the lever T is the lever U, connected by the rod V to the lever W,
the other end of which has a stud and friction roller which works in an
internal cam or eccentric b in the cone pulley B, and thereby receives an up-
and-down motion, which is transmitted to the ratchet R for giving motion to
the ratchet wheel Q and screw P. The connecting rod V is in two parts, the
lower part being furnished with a socket, the upper part works upon the
spindle v, upon which is fastened the ring v¹. Over the upper part is passed
the tube v3, which is screwed to the socket at the lower part, so that both
parts of the rod V may slide over or within each other when not prevented by
the spiral spring under and above the ring v¹. When the machine is in
operation, the rod V works as though it were of one piece, and communicates
the required motion to the working parts. If the slide O should arrive at the
cud, or the workman not be near when the slide runs out, or that purposely

page_text: some check should be employed in order that there shall be no more cutting
than is required, then the ring v presses the spiral spring, and the two parts
of the rod V slide over and within each other, so that no action shall be given
to the working parts. The elastic holder for ordinary screw heads and nuts
is composed of the part A', which is fastened by screws in the slide M ; in it
turns the socket B', having a plate which has three divisions or notches for
six-sided heads or nuts, and two divisions or notches for square heads or nuts.
At the lower part, the socket V' is cylindrical, and the other part has a thread
or screw, all being cylindrical, so that the nut C¹ which is fitted into the
thread may bo perfectly central. The split socket D¹ is conical on the outside
and fitted into the conical part of C', and the lower part of D¹ is fitted into
the internal cylindrical part of B¹, so as to maintain the parts central. When
the nut C' is screwed on the split socket D¹, then the latter is pressed inwards
and the bolt fastened and centred, because the said split socket is centered
both at D' and B', and its conical part will likewise be centered by the nut C³,
which is pressed in the part B'. The cover E¹ holds the aforesaid parts
together, and by being closely fitted, as is also the small cover F¹, no dirt or
dust can enter. The ring G¹ is placed under the tightened bolt, so that the
tools may act freely upon the entire depth of the sides of the head or nut.
In order to fix screws or bolts which have a smaller diameter than the upper
part of the socket D', other split sockets may be placed in the socket D', or
sockets similar to D' on the outside, but having smaller internal diameters,
may be employed.
In order to shape nuts, bolts K are fixed in the socket D', and the nuts
screwed upon them, as shewn in the detached Figure 35.
When the cutters are in action, the latch Fe in the holder or socket K' is
pressed in one of the notches by the spring L', but when the two opposite
sides of the head or nut are shaped, the latch will be drawn back by the
lever M, and then the head or nut must be turned until the latch F³ falls
into the next notch.
The clastic holders tighten upon and hold firmly round bodies in a perfectly
concentric position, as will be evident from the foregoing description, inas-
much as the exterior conical part of the split socket is pressed against a
corresponding internal cone, and also because the lower cylindrical part of the
socket is concentric whether for the centering of the heads or nuts.
Having thus fully described the nature and particulars of the said Invention,
as communicated to me from abroad by Richart Hartmann, of Chemnitz, in
the Kingdom of Saxony, I desire it to be distinctly understood that I claim,
the combination and arrangement of the machinery or apparatus for the

page_text: manufacture of screws, bolts, and nuts, as herein described and illustrated in
the accompanying eleven Sheets of Drawings.
In witness whereof, I, the said Frederick Allen Leigh, have hereunto
set my hand and seal, this Thirteenth day of April, in the year of
our Lord One thousand eight hundred and sixty.
Signed, sealed, and delivered by the within-
named Frederic Allen Leigh, in the
presence of
E. J. HUGHES, Patent Agent,
Manchester.
F. A. LEIGH. (L.S.)