IMPROVE- MENTS IN THE MANUFACTURE OF ORNAMENTAL AND OTHER TWISTED METAL WORK. AND IN THE MACHINERY, APPARATUS, OR MEANS EMPLOYED THEREIN
Year: 1870

page_text: LETTERS PATENT to Stephen Tuddenham, of Lower Marsh, Lambeth,
.
in the County of Surrey, Engineer, for the Invention of "IMPROVE-
MENTS IN THE MANUFACTURE OF ORNAMENTAL AND OTHER TWISTED METAL
WORK. AND IN THE MACHINERY, APPARATUS, OR MEANS EMPLOYED THEREIN.”
"
Sealed the 22nd December 1870, and dated the 16th July 1870.
PROVISIONAL SPECIFICATION left by the said Stephen Tuddenham at
the Office of the Commissioners of Patents, with his Petition, on the
16th July 1870.
I, STEPHEN TUDDENHAM, of Lower Marsh, Lambeth, in the County
of Surrey, Engineer, do hereby declare the nature of my Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF ORNAMENTAL AND OTHER TWISTED
METAL WORK, AND IN THE MACHINERY, APPARATUS, OR MEANS EMPLOYED
THEREIN," to be as follows:-
This Invention relates to certain improvements upon and additions
to the Invention for which I obtained Letters Patent, bearing date the

page_text: 14th of June 1867, No. 1739, whereby superior ornamental effects are
obtained and facility is afforded for manufacturing twisted screw spindles
for ordinary purposes, and for making grooved beater bars suitable for
thrashing, scutching, and other like machinery.
According to these improvements I propose when twisting several of
the prepared bars together to lay them parallel, or to group them in
such a position as will give the ornamental effect required, and to hold
such bars in their respective places by means of rings or ferrules, and
small wedge or filling pieces applied to the ends thereof in conjunction
with lead strips in the intermediate portion, such lead strips or filling
pieces and wedges being inserted between the fillets or projecting ribs
which have been previously formed on to the bars. The ends of the bars
when made of iron or steel are welded together along with the end
filling pieces, but when a metal is used which is not capable of welding
then the ends may be secured by screw clamps. Screw clamps are
however in all cases employed for keeping the several bars of the
group in their respective places during the operation of twisting, these
latter being placed at intervals along the group and tend to equalize the
twist and ensure uniformity therein. These bars so grouped and held
together by the screw clamps may be twisted together so as to form a
compound twisted bar, having either a solid or a hollow section. These
twisted bars as well as single twisted bars are sometimes ornamented by
having socket pieces or bosses placed thereon, such socket pieces or
bosses being formed with an opening therein of a shape corresponding
to the section of the group, or to that of the single bar, as the case may
be, and are secured in their places by the act of twisting the bars. In
order to prevent such socket pieces or bosses from being burst open or
split by the twisting of the bars, support or strengthen them during
the operation of twisting by means of screw clamps at each end, where
practicable suitable bearing or pressing plates being interposed between
the screws of the clamps and the sides of the socket pieces or bosses.
Further ornamental effects may be obtained by forming leaves or
branches or scroll work upon such bosses, and by twisting into the
group of bars branches or scroll work carrying leaves, fruit, or flowers.
In some cases I produce highly ornamental twisted metal work by
combining together bars of different sections and of different metals, the
same being held together during the operation of twisting by the screw
clamps herein-before referred to placed at such intervals along the bars

page_text: as to ensure uniformity of twist. One or other of the bars may have
leaves, branches, or scroll work formed thercon before it is twisted,
whereby a further ornamental effect will be obtained.
Although this Invention will be found more particularly applicable to
the production of twisted metal work of an ornamental character it is
also applicable to the manufacture of screw spindles and beater bars for
machinery of various kinds.
In producing a screw spindle according to this Invention I take a
prepared bar having two, three, or more longitudinal parallel ribs rolled
or otherwise formed thereon, which bar I either twist in a cold state or
I heat it and then twist it until an approximation to the desired pitch is
obtained, one end of such bar being secured in a revolving chuck whilst
the other end is secured in a die capable of sliding by friction along a
fixed metal frame or holder, in order to allow of the shortening of the
bar as the twisting proceeds. The twisted bar is then taken out of the
twisting machine and reheated, and is then placed in another machine
for the purpose of equalizing the pitch.
The twisting machine referred to in this Specification is in its general
construction similar to that described in the Specification of my said
Patent with improvements applied, which will be herein-after referred
to, but the machine for equalizing the pitch of the screw above
mentioned is a novel and additional appliance, and consists of a master
screw spindle of a pitch corresponding to the one intended to be
produced, which is coupled thereto by a clutch box or clip at one end.
The master screw is supported in and travels through suitable bearings
forming fixed nuts, and the screw to be operated upon passes through a
master or shaping nut or die forming the exact counterpart of the screw
thread to be produced; this master or shaping nut is made in halves
capable of being tightened to any extent on the screw spindle operated
upon by means of a pinching screw, and is carried on a fixed headstock.
On rotating the master screw the screw to be finished is also rotated
within the master or shaping nut, and is drawn or impelled forward as
it rotates by the action of the master screw. By thus traversing the
screw two or more times through the master or shaping nut, and
tightening the said nut at each traverse, the spirals on the bar will be
equalized, and will ultimately correspond exactly in pitch with the
master screw. By dividing or sawing these screw spindles longitudinally
they may be made to serve as grooved beaters for thrashing, scutching,

page_text: and other like machinery. In lieu of depending solely upon the friction
of the clamp holder in the twisting machine upon the bed for exerting
sufficient resistance to keep the bar distended and therefore straight
during the twisting operation, I propose to apply a positive and
adjustable drag or resistance thereto by employing an adjustable friction
break, whereby the amount of resistance can be adjusted to the greatest
nicety to suit the character of the bar or bars undergoing the twisting
operation. In some cases however I propose to permanently fix the
clamp holders so that the twisted bar shall be subjected to the maximum
tensile strain during the operation of twisting, whereby a greater
uniformity of twist in some cases is obtained by reason of the said
twist being equally distributed throughout the entire length of the bar
between the chuck and clamp holder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Stephen Tuddenham in the Great Seal Patent
Office on the 16th January 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, STEPHEN
TUDDENHAM, of Lower Marsh, Lambeth, in the County of Surrey,
Engineer, send greeting.
of our
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of July, in the year
Lord One thousand eight hundred and seventy, in the thirty-fourth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Stephen Tuddenham, Her special licence that I, the
said Stephen Tuddenham, my executors, administrators, and assigns, or
such others as I, the said Stephen Tuddenham, my executors, adminis-
trators, or 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 THE MANUFActure
OF ORNAMENTAL ADD OTHER TWISTED METAL WORK, AND IN THE MACHINERY,
APPARATUS, OR MEANS EMPLOYED THEREIN," upon the condition (amongst
others) that I, the said Stephen Tuddenham, my executors or adminis-
trators, by an instrument in writing under my hand and seal, should

page_text: 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 Stephen Tuddenham, do hereby
declare the nature of my 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 Drawings here-
unto annexed, and to the letters and figures marked thereon, that is to
say:
My said Invention relates to certain improvements upon, and additions
to the Invention for which I obtained Letters Patent, bearing date
the Fourteenth of June One thousand eight hundred and sixty-seven,
No. 1739, whereby superior ornamental effects at a much cheaper rate
than heretofore are obtained by twisting specially prepared bars, and
facility is afforded for manufacturing twisted screw spindles for ordinary
purposes and for making grooved beater bars suitable for thrashing,
scutching, and other like machinery.
In carrying out my present improvements I propose when twisting
together several of the prepared bars, having projecting ribs or fillets
thereon, to lay them parallel, or to group them in such a position as will
give the ornamental effect required, and then to hold or secure such bars
in their respective places in the group, whilst their ends are being united
together by welding, by driving on to the ends of the group rings or
ferrules one of which is shewn at A in Figure 1 (Sheet 1) of my Drawings.
This Figure represents a partial vertical section of a group of four pre-
pared bars, shewn in transverse section in Figure 2, one of the bars
detached being shewn in section at Figure 3. In conjunction with
these ferrules A. small wedges or filling pieces a, a, are also applied
to the ends of the bars in combination with lead strips or filling pieces,
which latter are applied to the intermediate portion of the length of the
group of bars, such lead strips or filling pieces and wedges a being
inserted between the fillets or projecting ribs b, b, (shewn clearly in the
cross section of one of the group of bars detached at Figure 3,) which
have been previously formed on the bars. I prefer to form these prepared
bars by rolling, although they may in some cases be formed by drawing.
c is a central bar or core of rectangular section, round which the
prepared bars are arranged. The ends of the bars, when such bars are

page_text: made of iron or steel, are welded together (after the ferrules A have
been driven thereon) along with the end filling pieces a, a, but when
a metal is used which is not capable of welding, such for example as
brass, copper, and gun metal, then the ends of such bars may be secured
by screw clamps, or by brazing in lieu of ferrules. Screw clamps are
however in all cases employed for keeping the intermediate portions of
the length of the several bars of the group in their respective places
during the operation of twisting, these latter being placed at intervals
(as shewn at B, B, in Figures 1 and 2,) along the group and tend to
equalize the twist and ensure uniformity therein; these bars so grouped
and held together by the screws c¹, c¹, of the screw clamps may be twisted
together so as to form a compound twisted bar, as shewn in Figure 4,
having either a solid or a hollow section according as the central
core c is employed or omitted. These groups of twisted bars as well as
single twisted bars are in all cases twisted whilst in a cold state, and
are sometimes ornamented by having socket pieces or bosses C of cast-
iron or other cast metal, or of what is known as malleable metal, placed
thereon, as shewn in Figures 5 and 6, such socket picces or bosses being
formed with an opening therein of a shape corresponding to the section
of the group, or to that of the single bar, as the case may be, and are
secured in their places by the act of twisting the bar or bars. Figure 7
is a section of two prepared wrought-iron rolled bars, placed back to
back, which when twisted together produce the design shewn in the
upper part of Figure 5. Figure 8 is a section shewing the form and
arrangement of three bars disposed round a triangular bar or core c,
which when twisted together produce the design shewn in the lower
part of Figure 5. Figure 9 is a section of the single bar, which when
twisted produces the design shewn in Figure 6. In order to prevent
the socket pieces or bosses when of a weak section from being burst
open or split by the twisting of the bars, I support or strengthen them
during the operation of twisting by means of screw clamps or rings D, D,
provided with screws d, d, shewn in section in Figure 10, at cach
end of the said socket or boss, where practicable suitable bearing or
pressing plates e, e, being interposed between the screws of the clamps
and the sides of the socket pieces or bosses C. Further ornamental
effects may be obtained by casting either in ordinary cast iron or in
malleable metal leaves or branches or scroll work E or other ornaments
upon such bosses, as shewn in Figure 11, or upon the bars after they have
been twisted, and by twisting into the group of bars other bars which

page_text: may be of a different metal (see g, Figure 13), having or not branches
or scroll work cast thereon in imitation of leaves, fruit, or flowers, or
branches or scroll work may be inserted into the group of bars and then
twisted therein. In some cases I produce highly ornamental twisted
metal work by combining together bars of different sections and of
different metals, as shewn in Figures 12 and 13, where f, f, are two
wrought-iron bars combined together with a flat bar or rod or fillet bar
of brass g formed with round, square, or other shaped beads or fillets on
cach edge of the flat part of the fillet bar g, fitting in between the
wrought-iron bars f, the same being held together during the operation
of twisting by the screw clamps, (herein-before referred to, and illustrated
at Figure 1,) placed at such intervals along the bars as to insure
uniformity of twist.
Figures 14 and 15 represent an ornamental device produced by com-
bining together two or more bars twisted in opposite directions; and
Figures 16 and 17 represent corresponding sections of the bars so
twisted and combined.
Although this Invention will be found more particularly applicable
to the production of twisted metal work of an ornamental character,
it is also applicable to the manufacture of screw spindles for machinery
of various kinds, and beater bars for thrashing machines (see Figure 18).
In producing a screw spindle according to this Invention I take a
prepared rolled section wrought-iron bar, having two, three, or more
longitudinal parallel ribs rolled thereon, as shewn in section at Figure 19,
which bar I first twist in a cold state, after which I heat it and then.
twist it until the pitch is rather less than the final pitch required.
When producing the first or cold twist, I secure one end of the bar in
the revolving chuck of the twisting machine herein-after described,
whilst the other end of such bar is secured in a headstock, or holder,
capable of sliding with more or less resistance along the table or bed
of the machine to allow of the shortening of the bar as the twisting
proceeds. The cold twisted bar is then taken out of the twisting machine
and is heated, and is then replaced in the said machine with its outer
end secured in a sliding holder working in suitable guides fitted into
the headstock as herein-after described and illustrated on Sheet 2
of my Drawings. After this second twisting the bar is again heated
and placed in another machine, for the purpose of equalizing the pitch,

page_text: which is also herein-after fully described and illustrated on Sheets 3
and 4 of my Drawings.
Figure 1 (Sheet 2) of my Drawings represents a side elevation of my
improved twisting machine for producing ornamental or other twisted
work. In its general construction it is somewhat similar to the twisting
machine described in the Specification of my said former Patent herein-
before referred to. It is here shewn as a double machine, so as to be
capable of twisting two bars in opposite directions at the same time,
or of twisting a right hand and left hand thread on two portions of one
and the same bar. Moreover, with a view to regulating with greater
accuracy the amount of longitudinal tension on the bar whilst under-
going the operation of twisting, and thereby controlling more effectually
the degree of shortening of the said bar during such operation, I have
combined with the moveable holder or headstock an adjustable break.
Figure 2 is a plan of the machine corresponding to Figure 1; Figure 3 is
a transverse vertical section of the machine taken along the line 1, 2, in
Figure 1, and shewing a face view of one of the pair of rotatory chucks ;
Figure 4 is a front view of the sliding headstock, and Figure 5 is a
similar view of the fixed headstock and sliding holder which I employ
when producing the second or hot twist in a bar intended to form a
screw spindle.
In the several Figures herein-before last referred to A represents a
long lathe bed, and B is a stationary poppet head carrying the gearing
for actuating the two rotatory chucks C, C₁3B these two chucks are
each made fast on the respective ends of the tubular shaft D, working
in suitable bearings E, E, in the poppet head. A dovetailed groove is
made diametrically across the face of each chuck, in which groove are
fitted two adjustable dies or holders a, a, (Figure 3) capable of grasping
and firmly holding in a central position one end or other portion of the
bar to be twisted, the said holders a being tightened up and adjusted so
as to hold the bar in the axial centre of the chucks by the tightening or
adjusting screws b, b.
In my Drawings I have shewn the application of double driving gear
to the machine, but it is obvious that single gear may be employed pro-
vided the power be sufficient to perform the work in hand. This gearing
consists of a spur wheel F fast on the tubular shaft D, and a second spur
wheel F¹ and pinion G formed thereon running loose on such shaft.
H is a driving pinion sliding along a feather on the shaft I, and thrown

page_text: into gear with the wheel F or F", as the case may be, by means of a
clutch lever K. The shaft I works in bearings L, L, and carries a mitre
wheel M, which derives motion from the mitre wheel N fast on the
driving or first motion wheel O, which works in the bracket bearings
P, P, and is provided with the ordinary fast and loose driving pullies
Q, Q. The pinion G before referred to gears into the spur wheel R,
fast on the shaft S, which works in the bearings T, T; this shaft S carries a
pinion U, which gears into the spur wheel F fast on the tubular shaft D.
The Drawing, Figure 2, shows the gearing adjusted for double power,
the rotatory motion of the chucks being transmitted through the pinion H,
wheel F', pinion G, wheel R, pinion U, and wheel F. By simply moving
the pinion H so as to bring it into direct gear with' the wheel F then the
power will be reduced. In this latter case the pinion U may also be
thrown out of gear with the wheel F, so as to leave the gearing F, G, R,
and U at rest; or in lieu of this arrangement the pinions H and U may
be both fast on their shafts I and S, and the shaft S with its gearing R
and U made to slide to and fro by means of an eccentric motion or
sliding bearings worked by a single lever, whereby the wheel R and
pinion U can be thrown in or out of gear with the pinion G and wheel F
as required, the wheels F and F" being connected together when single
power is required by a locking bolt or pin passing through them. V is
the sliding headstock or holder, shewn also at Figure 4, which grasps
the outer end of the bar to be twisted, the square-sided end of such bar
being nipped in the rectangular opening c (Figure 4) formed between the
body of the headstock and the cap. d, which latter is tightened by means
of the bolts e, e; the opposite end of the said bar is also gripped beween
the adjustable dies or holders a, a, in the chuck C, and on imparting a
slow and powerful rotatory motion to such chuck the bar is gradually
twisted to any desired extent. In order to allow of the shortening of
the bar during the twisting process, and at the same time to exert just so
much resistance to longitudinal contraction as will ensure uniformity in
the spirals, the headstock V is allowed to slide along its bed but is con-
trolled in its movement by connecting it by a chain W to a windlass
barrel X, the shaft of which works in bearings fixed to the end of the
bed; this shaft carries a break wheel Y, round which a break strap ƒ is
passed, and tightened more or less by the adjustable weighted break.
lever Z. If two bars be required to be twisted at the same time in
opposite directions, or if a single bar is to be twisted in opposite directions

page_text: at each end, (by passing it through the tubular shaft D and holding it
by one or other of the chucks C, C¹,) a similar sliding headstock and
break will be fitted to the opposite end of the bed.
In my Drawings I have represented at the right-hand end of the
twisting machine the arrangement I propose to adopt when producing
the second or hot twist on a bar intended for a screw spindle. It consists
of a fixed headstock 9 provided with a grooved bridle piece h (see also
Figure 5) held in a central position by the screws h¹, h', within which
bridle piece slides freely a holding block or die i for the reception of the
end of the already partially twisted bar, the other end being secured in
the clutch C¹. As the twisting proceeds the shortening of the bar is
assisted by forcing up against it the end of the screw spindle k carried in
the headstock 1, by which arrangement I avoid all longitudinal tensile
strain on the heated bar during the operation of twisting.
Figure 1 (Sheet 3) represents a sectional elevation of one arrangement
of the machine I propose to employ for equalizing the pitch when making
a twisted screw spindle according to this Invention; Figure 2 represents
a front elevation and transverse section of the headstock carrying the
pitch equalizing die, and shewing a portion of the twisted screw spindle
therein; Figure 3 represents 2 enlarged sectional details of the driving
pulley.and its connection with the master screw. The bar having under-
gone the second or hot twisting process in the improved twisting machine
herein-before described, is placed in this machine, or in the modified
arrangement herein-after described with reference to Sheet 4, in order
to ensure a perfect uniformity of pitch. For this purpose I heat the
said twisted bar and place it in the equalizing machine, which consists
of a bed A somewhat similar to a lathe bed, having secured thereon
at suitable intervals according to the length of twisted bar to be operated
upon the four headstocks or brackets B, C, D, and E, the bracket D
being made double, and containing the driving pulley F in the middle.
G is the master screw spindle, having a square threaded screw cut
thereon of a pitch and direction corresponding to that to be produced on
the finished screw spindle H. This master screw works through nuts a, a,
fitted in the brackets D, and has a longitudinal slot or keyway 6 cut
along it, in which engages a key or internal feather b¹ secured to the
boss of the driving pulley F. The master screw is perfectly free to slide
longitudinally to and fro through the boss of the driving pulley, from
which it at the same time derives a rotatory motion in its internally

page_text: screwed bearings or fixed nuts.a, a. In the bracket C is fitted another
nut c, the same in all respects as the nuts a, a, in the brackets D, and
through which the master screw G also works, the object of using two or
more bracket supports being to insure the steadiness of the master screw
when in operation. I is a coupling or clamp which serves to connect in a
secure manner the end of the master screw G with the end of the screw H
to be operated upon, the opposite end of the screw H, which is heated to
the requisite degree before being brought to the machine, being engaged
between the two halves of the master or shaping nut or die d (Figure 2),
contained in the bracket B. The two halves of this die have internal
scrow threads formed in them of the form and pitch to be produced on
the screw H, such threads having a rounded form, as shewn clearly in
Figure 2, in order to prevent the bar operated upon from being cut or
injured whilst undergoing the adjustment of the pitch. The upper half
of the die d is free to slide vertically in a slot or opening made for that
purpose in the bracket B, and both halves are provided with lateral
lips or flanges to keep them in position in the said bracket. K is a
pressure regulating screw worked by a hand wheel, which serves to force
down the top half of the die slightly at each passage of the screw H
through the dies. In order to prevent undue sagging of the heated
screw between the coupling I and the bracket B, a tumbler or weighted
lever support L is provided, which is forked at its upper end so as to
embrace and support the screw H, this tumbler being pivotted at e in
order to be capable of moving out of the way during the passage over
it of the coupling, and of righting itself after the coupling has passed.
The overhanging end of the master screw is supported and steadied by
entering the stationary bracket E, which is formed with a groove or
channel having an expanded mouth, so that the overhanging end of the
said screw spindle will always find its way therein. The driving pulley
is driven by a strap from a pulley M on the overhead shaft N which is
fitted with the well known arrangement of reversing pulleys driven
respectively by open and cross straps, in order that the screw H may be
alternately rotated and traversed in opposite directions until the dies
have imparted the desired uniformity of pitch to the spirals requisite for
a screw spindle.
Figure 1 (Sheet 4) represents a side elevation of another-modification
of pitch equalizing machine, wherein one of the pitch equalizing dics
is made to revolve in contact with the screw under treatment in lieu of
both halves of the said die being stationary, as in the machine illustrated

page_text: on Sheet 3 of my Drawings. The object of making one of the dics
rotate is to assist the screw spindle under operation in its longitudinal
travel and thereby obviate the longitudinal tensile strain to which it
would be subjected when gripped between a pair of stationary dies, as
previously described. Figure 2 is a plan of the machine corresponding
to Figure 1. Figure 3 is a transverse section taken along the line 1-2
in Figure 2, and shewing a front view of the main poppet head and
driving gear, and Figure 4 is a transverse section taken along the
line 3-4 in Figure 2, and shewing a front view and partial section
of the adjustable headstocks which carry the pitch equalizing dies..
A is the bed of the machine similar to a lathe bed; B is a fixed poppet
head carrying the actuating gear herein-after described for rotating the
master screw C; D is a bracket for supporting the overhanging end of
the master screw; E is the coupling which connects the master screw
with the twisted screw F to be operated upon;B G is a weighted tumbler
for supporting the screw F and allowing of the passage to and fro of the
coupling E; H is a bracket for supporting the overhanging end of the
screw F. The master screw C works in fixed nuts in the bearings I, I,
and carries a mitre wheel K, through which the master serew is free to
travel longitudinally, whilst it is at the same time rotated thereby, a
slot a being made along the screw in which a key or feather in the
boss of the bevel wheel engages; L is the driving or first motion shaft
working in bearings M, M, and provided with a spur pinion Q, and with
fast and loose driving pullies N, N¹, N", driven by open and crossed
The spur
straps as required, so as to obtain a reversing motion.
pinion on the shaft L gears into a spur wheel Q' fast on a short
shaft Q working in bearings M², M', and carrying a mitre wheel K',
which gears
into the mitre wheel K on the master screw, the speed of
the master screw being one-fourth that of the driving shaft L. The
shaft L carries a single thread worm O in gear with the worm wheel P,
containing 34 teeth fast on a short shaft R working in bearings S, S;
this shaft R is connected by a universal joint T with a back shaft U,
which is connected at its opposite end by another universal joint V to a
short shaft W working in the bearings X, X, in the adjustable head-
stock Y (Figure 4). Between the two sides of the headstock and
mounted fast upon the short shaft W is the rotatory die Z, which
consists of a disc, the periphery of which has a screw thread formed
thereon of the same pitch as that to be produced on the twisted bar or
screw F, but the said screw threads should be made of a tapered section,

page_text: that is to say, rather narrower at the periphery than at the base, for
the purpose herein-after explained. 6 is another adjustable headstock
carrying a half nut c forming the fixed part of the pitch regulating die,
the screw spindle to be operated upon being nipped between the rotatory
die Z and the fixed dic c, as shewn clearly in Figure 4. With a view to
opening and closing the dies so as to admit of the screw F being placed
in and removed therefrom the two headstocks Y and 6 are caused to
slide transversely to the main bed A along the cross bed or plate d, by
means of a right and left hand screw spindle e working in nuts f,f, on
the respective headstocks, and actuated by the hand wheel g. The bed
or plate d is also capable of being slid along the bed A, and is secured
firmly in any desired position on the main bed A by means of the
tightening nut h. The screw to be operated upon is to be properly
heated, and then coupled with the master screw and placed between the
rolling and fixed dies Z and c. These two dies are then caused to nip
slightly the screw spindle by turning the hand wheel g, and the machine
is started by rotating through the gearing already described, the master
screw and the rotatory die, the rotatory motion of which is so arranged
as that its surface speed will be equal to the surface speed of revolution
of the screw to be operated upon, thereby avoiding actual rubbing friction
between them and removing end strain from the screw, which as it
rotates is caused to travel to and fro longitudinally between the
equalizing dies. On commencing the operation the die threads will only
penetrate a short distance between the screw threads, and will gradually.
open or spread them out, the dies being brought closer and closer at cach
passage of the screw until the desired pitch is produced.
Having now described and particularly ascertained the nature of my
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. The system or mode of holding the several bars of a group in
their respective positions, whilst being twisted together in a cold state by
means of screw clamps or other equivalent means, substantially as and
for the purpose herein-before described.
Second. The welding or brazing together or the securing by means of
screw clamps of the ends of a group of bars preparatory to twisting the

page_text: same in conjunction with the use of filling pieces, substantially as and for
the purpose herein-before described.
Third. The fitting of socket pieces or bosses upon metal bars before
twisting them, and the securing of such socket pieces or bosses in their
places by the mere twisting of the bar or bars, as herein-before described.
Fourth. The system or mode of preventing the rupture or bursting
of the said socket pieces or bosses during the twisting of the bar or bars
upon which they are placed by the use of screw clamps and bearing or
pressing plates as herein-before described.
Fifth. The casting of leaves, branches, or scroll work upon fillet bars
intended to be twisted into a group or between two wrought-iron bars, or
the casting of the same upon socket pieces or bosses intended to be
placed on bars to be subsequently twisted, or the placing of such leaves,
branches, or scroll work into a group of bars, and twisting the whole
together for the production of greater ornamental effects, substantially as
herein-before described.
Sixth. The manufacture of screw spindles (suitable for grooved beater
bars and other purposes), by first twisting a properly prepared bar in a
cold state, then twisting it in a heated condition, and finally equalizing
the pitch, substantially in the manner herein-before described.
Seventh. The application and use to and in the equalizing of the pitel
of the threads of a screw spindle produced by twisting of adjustable dies,
either both stationary or one stationary and the other rotatory, in com-
bination with a master screw, substantially as herein-before described.
Eighth. The application of an adjustable break to the moveable head-
stock or holder of the twisting machine, substantially as and for the
purpose herein-before described.
´In witness whereof, I, the said Stephen Tuddenham, have to this
my Specification set my hand and seal, the Thirteenth day of
January One thousand eight hundred and seventy-one.
STEPHEN TUDDENHAM. (L.S.)