IMPROVEMENTS IN THE MANUFACTURE OF SCREWS,, NUTS, AND OTHER SCREWED OR THREADED ARTICLES, AND IN
Year: 1881

page_text: LETTERS PATENT to James Mackintire, of Tudor Street, in the City of London;
Engineer, for an Invention of IMPROVEMENTS IN THE MANUFACTURE OF
SCREWS,, NUTS, AND OTHER SCREWED OR THREADED ARTICLES, AND IN THE
PROVISIONAL SPECIFICATION left by the said James Mackintire at the
Office of the Commissioners of Patents on the 31st March 1881.
JAMES MACKINTIRE, of Tudor Street, in the City of London, Engineer.
IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, NUTS, AND OTHER SCREWED
OR THREADED ARTICLES, AND IN THE APPARATUS TO BE USED IN SUCH MANU-
FACTURE."
The. object of this Invention is to effect an economy in the manufacture of
screwed and threaded articles by rendering it unnecessary to form such articles
first in the blank, then to bore or turn the blanks to shape, and afterwards to cut
the threads upon them by screw taps, dies, or other threading tools. .
In attaining this object I employ a novel mode of preparing moulds for casting
in a complete form the articles intended to be produced.
Supposing, for example, it is required to manufacture nuts for bolts or coupling
sockets; according to this Invention I form a number of solid metal patterns with
aiprintas.usual, and fit. these, print upwards, on a plate furnished with pins set at
equal distances apart to receive respectively a pattern. This pattern plate, which is.
also furnished with lines of projections to produce gates" in the sand mould, I
then surround by a hinged flask or mould box, and having oiled the patterns and
washed them over with a coating of a composition to be hereafter described, I fill
the flask with the preparation of the moulding 'sand or loam. I then submit the
sand mould to pressure in order to solidify it and make it hard enough to handle.
I-next turn over the mould, remove the pinned pattern plate, which leaves the
patterns. imbedded in the mould. These I remove in the well known manner from
the sand, and I then complete the 'sand mould by inserting screwed' cores in each
nut cavity.
•

page_text: These cores I form in a core press fitted with a die box of peculiar construction,
and containing a pair or it may be a number of pairs of threaded dies. Over each
die is mounted a vertical plunger for ramming the sand into the threaded die, and
forming therein a solid core.
The die box is made in two halves, which are connected together by a vertical
hinge at one end, and secured by a latch at the other. This die box is secured by
a horizontal hinge to the swinging bed plate of the press to enable the die box to
be drawn out from the press when it is required to open it to remove the moulded
cores therefrom.
The screwed core is made with a plain part to fit the hole in the sand mould
formed by the print on the metal pattern of the nut.
To ensure a good impression the threaded dies after being oiled are washed over
like the nut patterns with the composition to be presently described.
The core moulded in this press is formed with a central hole in its end (produced
by a coned projection on the swinging plate of the press) to facilitate its removal
from the die box.
The screwed cores produced in this press are carefully inserted in the sand mould
already described, and there represent the counterpart of the thread which the nuts,
when cast, are intended to receive.
A number of sand moulds produced in the manner described with backs having
a smooth finish are set on end in a hinged box prepared to receive them, and
brought together, so that the back of one sand mould stands in close contact with
the face of the adjacent mould.
Through all these moulds a runner hole is made to form a horizontal channel for
the casting metal, which is supplied to the moulds by a plunger working in a
cylinder connected with a supply reservoir.
When preparing moulds for screws or screwed glands which have a flat sided
head of greater diameter than the screw, I first mould the head in the way described
with respect to the nut, and I then mould the screwed portion from a metal
pattern separate from the head, and in the same manner as described with respect
to the nut.
This pattern I form with a central tapped hole to receive a screwed rod for
removing it from the sand. This rod or a series of them I mount in a frame which
is capable of being placed upon the flask containing the sand mould in such position
that its screwed rod or rods will correspond to the screws that are to be withdrawn
from the sand.
The screwed rods are fitted at their upper end with a screw thread corresponding
in pitch with the pattern screw, and this screwed thread works in a
a cross bar of the frame.
tapped hole in
On opposite sides in the central hole in the screw are holes to receive pins which
project from the lower end of a tube that is loose on the screwed rod. This tube is
free to slide vertically on the rod, but is caused to rotate with it by means of a
guide and locking pin. To remove the screw from the sand mould the screwed rod
is turned until it takes a hold of the screw; the sliding tube is then dropped onto
the screw that its pins may lock in the holes formed therein, and when this is
effected the further turning of the screwed rod will screw the pattern screw slowly
out of the sand.
The two sand moulds thus prepared, representing the one with the screw and
the other the head of the screw intended to be cast, are brought together so that
they will properly register, and being packed in a casting frame, after the manner
already explained, the metal is run into the moulds, and the casting is completed. -
In preparing the material for the moulds for casting metal nuts, screws, and
other threaded articles, the clay or fine loam is first dried and ground, and when
required for use it is moistened sufficiently to enable it to adhere together.
The pattern is then cleaned and oiled, and coated with a fine slip paste made
from loam and kaolin or china clay of equal parts, which must be ground very fine
and sifted through a fine sieve. This paste is formed by dissolving, say, one and a

page_text: half ounce of gelatine in one gallon of water, and adding thereto four ounces of
glycerine with half an ounce of carbolic acid to form the moistening medium. To
this solution is added as much of the finely prepared loam and kaolin as will produce
a thick paste or dough, which can be kept any length of time for use.
In preparing a mould for casting this prepared paste is diluted with water to the
consistency of a thick cream, and with this, after oiling, the pattern is coated by
the aid of a soft brush. The pattern is then placed in position, as already
described.
When the back of a single mould requires a smooth and fine surface, a little dry
kaolin or china clay should be shaken on the top of the filled mould box before
pressing the mould, and when a double mould is required registering pins must be
provided, so that the sectional patterns may join correctly. Metal "gate" patterns
are preferably used, running from the injection passage to the patterns to save hand
gating" after the mould leaves the press.
66
By these means a perfectly smooth and sound mould is obtained, which must be
placed to dry for a few hours, and then baked before being used.
The old clay moulds ground up can be again used with an equal amount of newly
prepared loam, and this mixture is better than all new clay.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Mackintire in the Great Seal Patent Office on,
30th September 1881.
the
JAMES MACKINTIRE, of Tudor Street, in the City of London, Engineer.
"IMPROVEMENTS IN THE MANUFACTURE OF SCREWS, NUTS, AND OTHER SCREWED
OR THREADED ARTICLES; AND IN THE APPARATUS TO BE USED IN SUCH MANU-
FACTURE,"
The object of this Invention is to effect an economy in the manufacture of screwed
and threaded articles by rendering it unnecessary to form such articles first in the
blank, then to bore or turn the blanks to shape, and afterwards to cut the threads
'upon them by screw taps, dies, or other threading tools.
In attaining this object I employ a novel mode of preparing moulds for casting
in a complete form the articles intended to be produced.
Supposing, for example, it is required to manufacture nuts for bolts or coupling
sockets; according to this Invention I form a number of solid metal patterns with
a print" as usual, and set these, print upwards, on a plate furnished with pins at
equal distances apart to receive respectively a pattern.
66
66
"
This pattern plate, which is also furnished with removable lines of projections to
produce gates' or ways for the molten metal in the sand moulds, I then
surround by a hinged flask or mould box, and having oiled the patterns and
washed them over with a liquid composition or slip, to be hereafter described, I fill
the flask with the preparation of the moulding sand or loam.
I then submit the sand mould to pressure in order to solidify it and make it
hard enough to handle. I next turn over the mould and remove the pinned pattern
plate, which leaves the patterns imbedded in the mould. These I remove in the
well known manner from the sand, and I then complete the sand mould by inserting
screwed cores in each nut cavity.
These cores I form in a core press fitted with a die box of peculiar construction,
and containing a pair or it may be a number of pairs of threaded dies. Over each
die is mounted a vertical plunger for ramming the sand into the threaded die, and
forming therein a socket threaded core.
The die box is made in two halves, which are connected together by a vertical
hinge at one end, and secured by a latch at the other. This die box is secured by
a horizontal hinge to the swinging bed plate of the press to enable the die box to
be drawn out from the press when it is required to open it to remove the moulded
cores therefrom.
The screwed core is made with a plain part to fit the hole in the sand mould
formed by the print on the metal pattern of the nut.
The screwed cores produced in this press are carefully inserted in the sand 'mould
already described, and there represent the counterpart of the thread which the nuts
when cast are intended to receive.
A number of said moulds produced in the manner described after being dried and
baked are set on end in a hinge casting box or flask prepared to receive them, and
brought together, so that the back of one sand mould stands in close contact
with the face of the adjacent mould, and forms the surface for one face of
the nut.
Through all these moulds a runner hole is made to form a horizontal channel for
the casting metal, which is supplied to the mould by a plunger working in a
cylinder constituting the supply reservoir.
The means employed for manufacturing this nut are clearly shewn in the
Drawings, and will be first described before referring to the manufacture of other
and more complete articles.

page_text: '
In Sheet I., Fig. 1 is a partial plan view of a plate enclosed in a moulding flask,
and fitted with a number of nut patterns ready for receiving the moulding sand;
Fig. 2 is a cross section taken in the line 1, 2, of Fig. 1, and shewing the
moulding sand filled into the flask, and covering the plate on which the patterns
are fitted.
A is the pattern plate, standing up from which are pins a arranged in parallel
rows, and intended each to receive a nut pattern. This nut pattern consists of a
hexagonal blank formed with a core print *, and pierced in its centre to receive
the retaining pin a, and threaded for a purpose hereafter mentioned.
A runner hole is formed in the sand mould by means of a plug (slightly
tapered), which is fitted like the nut patterns to the plate A; connected with this
plug are half round projections d on the plate A, which projections form channels
or ways for the flow of the molten metal to the cavities formed in the sand by the
nut patterns.
The plate thus fitted is brushed over with oil, and the patterns are then coated
with "
slip while this is still wet the moulding sand is filled into the flask or
hinged mould box, and submitted to the action of a hydraulic press, for the purpose
of consolidating it. When the flask and mould are removed from the press
extract the plug, turn over the mould, lift off the plate A, and remove the hinged
flask B.
I
The next thing is to remove the patterns; this I do by lifting them singly by
means of a wire, which is secured at its end to enter the tapped holes in the pattern
to be drawn.
The next thing is to insert in the moulds screw cores, which are to form the
threads in the cast nuts; one of these cores is shewn detached at Fig. 1, Sheet II.,
and in place in the sand moulds at e, Fig. 3, in Sheet I.
To facilitate the manufacture of these cores I make by pressure a solid rope,
composed of loam and clay, and cut from this rope suitable lengths to form the
cores, which lengths I submit to pressure in a suitably shaped die to bring it to
the form shewn at Fig. 1, Sheet II.
In preparing this rope I use the instrument shewn in longitudinal section at
Fig. 4, Sheet I, which-consists of a horizontal cylinder C temporarily strapped to a
table, and fitted at one end with a moulding die, which gauges the diameter of the
rope to be made. In the open end of the cylinder fits a piston D, which is
attached loosely to a traversing screw D¹ working in a screwed bearing piece E
attached to the table.
When the cylinder is charged with the moulding compound I insert the piston
in the cylinder, and by means of a hand wheel keyed to the traversing screw I
rotate that screw slowly, and thereby force forwards the piston, which causes the
moulding material to exude from the die in the form of a rope, and in a solid state.
From this rope I cut off a suitable length, and having dipped it in slip I submit it
to the action of the die press shewn in several views in Sheet II., Fig. 2 being a
side view of the press; Fig. 3. a plan view; and Fig. 4, a vertical cross section of
the same. In these Figures, F is a bridge frame bolted to the bed plate; and
pivotted to the bed plate, so as to swing under the bridge frame, is a plate G serving
to carry the die box. This box is composed of two parts H1, H1, which are hinged
together, so as to allow of the die being thrown open to receive the material to be
moulded, and to facilitate the removal of the moulded core. This die box is hinged
to its plate G, so as to allow of its being turned down on its side, and it is while
the die is in that position that it is opened out for the removal of the moulded
core.
'
Fig. 5 shews the die in this opened position, the two half dies being exposed to
view. The half dies, it will be seen, are each fitted with a removable screwed
piece h, and they are formed with a half round groove in line with the screwed
piece, which grooves when the die is closed constitute a cylindrical space. This
space opens out into a hollow cone which forms a guide for a descending plunger I,
.*
.
..

page_text: or may be used as a hopper when loose material is employed from which to form
the core.
This plunger is connected by a link to a hand lever I¹ hinged to the frame F,
which frame may serve also as a guide for the plunger. Pressure is imparted to
the inserted clay when the die is closed and secured by a latch through the
plunger I by the hand of the attendant. The handle extending from the half H¹
of the die box serves to swing the same into and out of position for working, and
also to open out the die box.
A length sufficient to form a core cut from the rope moulded by the instrument
shewn at Fig. 4, Sheet I., is dipped into " slip," and then inserted in the closed
die box, the dies having first been brushed over with oil. The box is then pushed
back into position under the frame F, and pressure being applied to the plunger
the moulded core will be formed, one half of its length or thereabouts being
threaded, and the other half constituting a cylindrical stem which fits a corre-
sponding print hole in the sand mould and thereby holds the core in a central
position.
Standing up from the plate G concentric with the opening in the die box is a
coned pin g, which in the act of forming the core indents its screwed end, and thus
provides for the more secure holding of the core between the finger and thumb when
the attendant lifts the core out of the opened die box.
I have said that the core is shewn in place at Fig. 3. Sheet I., it is inserted in
the sand mould while that mould lies in a horizontal position, and when each
cavity of the mould is thus fitted with a core I place the moulds edgewise to dry.
After a few hours exposure to the air I submit the moulds to the heat of an
oven for the purpose of driving out all moisture therefrom. When dried I place
any suitable number of these moulds close together in a casting box, so that the
smooth back of the one mould may form a side face to the next adjoining mould,
as shewn also at Fig. 3.
By thus arranging the moulds I bring the runner holes of all the moulds into
line, and thus constitute a channel for the molten metal from which the nut
castings are to be formed.
This casting is shewn in longitudinal section at Fig. 1, Sheet III., where K is
a closed box of cast iron, formed with a hinged front back and cover and fixed
to a table.
"
+
The ends of this box are cast in one with the bottom of the box.
Fitted to one end of the box is a pressing plate K¹, which is intended to press
the sand moulds tightly together in the box, and it is for this purpose moved
forward under the pressure of a tightening screw K2 which works through a
threaded boss cast on the outer face of the adjacent end plate.
The opposite end plate is formed with a hole coincident with the runner holes
or channel in the moulds. Fitting into this hole in the end plate is a casting clay
heading K³, the inner face of which carries a cylindrical clay core projection to fit
the hole.
This clay heading or casting has a conical periphery to fit the chamfered end of
a horizontal cylinder L, which is itself fitted with a plunger L¹ for forcing the
molten metal forwards into the moulds.
The cylinder L is mounted on a slide L³, and is capable of receiving through a
traversing screw L below the table an endway motion for moving up the cylinder
into close contact with the conical face before mentioned to make a tight joint
therewith, and to draw it back from the casting box when the casting is effected.
This clay heading or casting K³, which closes the open end of the cylinder has a
central opening through it, which opening tapers outwards towards the cylinder.
Into this opening fits a hollow metal bush k, the bore of which tapers slightly
inwards or towards the moulds. This bush is intended to receive a plug of
baked clay, which closes the passage between the cylinder and the casting box.
Near the rear end of the cylinder and at its upper side is a funnel for receiving
the molten metal to be cast. The piston or plunger L' which serves to propel the

page_text: molten metal forwards stands at the back or closed end of the cylinder at the time
that the casting operation is to commence, and the cylinder. being forced up into
position is ready to be charged with the molten metal through the funnel.
When
thus charged the piston L' is pressed forwards by a screwed rod L*, which passes
through a threaded fixed bracket on the table.
On the advance of the piston the metal will drive forward the clay plug , and
thereby open up a passage for the molten metal to the several moulds in succession
and it will ultimately lodge in the last mould of the series. When the metal has
set the cylinder is to be drawn back by the traversing screw of the slide until it
is clear of the piston. This position being for convenience unattached to its rod
will when the pressure on it is slackened fall through an opening in the table, and
the casting box being now opened and the pressure of the plunger plate released
the moulds may be removed from the box.
To facilitate the cleaning of the cylinder, and lining it with plumbago after
every casting, I prefer to close its rear end with a fixed abutting screw piece
carried by the slide L2, and to hold it as in a cradle on that slide; this provides
for the ready removal and replacement of the cylinder.
Before proceeding to explain how other screwed or threaded articles are moulded
according to my Invention I will describe the method of preparing the material
for the moulds.
I use a mixture of fine loam and clay in the proportion, say, of from one to two
parts of clay to eight parts of loam. This mixture I dry and grind, and when
required for use I moisten it sufficiently to enable it to adhere together.
The pattern is then cleaned and oiled, and coated with a fine slip paste composed
of brick clay and kaolin or china clay of equal parts, which must be ground very
fine and sifted through a fine sieve. This paste is formed by dissolving, say, one
and a half ounces of gelatine in one gallon of water and adding thereto four
ounces of glycerine with half an ounce of carbolic acid to form the moistening
medium. To this solution is added as much of the finely prepared clay and
kaolin as will produce a thick paste or dough, which can be kept any length of
time for use.
In preparing a pattern for casting, this paste is diluted with water to the
consistency of a thick cream, and with this the pattern having been placed in
position on the pinned plate is coated by means of a soft brush. This preparation
when absorbed into the mould produces a fine surface, which ensures the pro-
duction of a casting of very superior quality. When the back of a single mould
requires a smooth and fine surface a little dry kaolin or china clay should be
shaken on the top of the filled mould box before pressing the mould, and when a
double mould is required, registering pins must be provided, so that the sectional
patterns may join correctly. Metal "gate" patterns are preferably used running
from the injection passage to the patterns as already explained to save hand
gating" after the mould leaves the press.
66
By these means a perfectly smooth and sound mould is obtained, which must.
be placed to dry for a few hours and then baked before being used.
The material forming the old clay moulds when ground up can be again used
with an equal amount of newly prepared loam, and this mixture is better than all
new clay.
Referring now to Figures 5 to 11 of Sheet I. I will proceed to explain the mode
of moulding a screw bolt suitable for the cast uut above described.
The pattern for the screw bolt is composed of two parts, viz., the head and the
threaded stem. Fig. 5 shews in plan view a pinned plate fitted with a number of
hexagon patterns for the head and surrounded by a hinged flask; Fig. 6 is a cross
section of the same taken in the line 3, 4, of Fig. 5; Fig. 7 shews in plan view a
pinned plate fitted with patterns of the screw stems and contained in a hinged
flask; and Fig. 8 is a cross section of the same taken at the line 5, 6, of Fig. 7.
The central holes drilled in the head and stem patterns are threaded for a

page_text: portion of their depth to receive the screwed end of a tool for lifting them out of
the pressed mould.
Fig. 9 shews the two parts of the screw, bolt mould placed together, the patterns
for the heads and stems having been carefully withdrawn from the mould.
One or other of the half moulds is formed with gates, as before explained, for
leading the molten metal from the runner hole to the cavities in the mould, and
the same precautions with respect to greasing the patterns and afterwards coating
them with a slip, as already explained, are used when moulding screw bolts, and
the various articles to which the Invention applies before filling the prepared
moulding material into the flask.
The patterns for the heads of the screw bolts may be readily drawn by the
moulder, but the patterns for the threaded stems must be screwed out of the mould,
and that with such care as to prevent the stripping or chipping of the thread of
the mould. For this purpose I employ the mechanical contrivance shewn in
sectional elevation and plan view at Figures 10 and 11, Sheet I., by means of
which all the screw patterns may be drawn out simultaneously. This apparatus
consists of a stiff rectangular frame M, in which is mounted vertically a number of
screwed spindles m corresponding in nuniber to the threaded patterns to be drawn,
say, for example, thirteen.
These spindles are formed at their upper end with a thread, corresponding in
pitch with the thread of the screws to be cast, and they work through tapped holes
in the upper plate of the frame.
The lower end of each screwed spindle m is threaded to enter the tapped hole in
the patterns, and the pitch of this thread corresponds with the pitch of the
thread on the upper part. of the spindle. Surrounding the lower portion of the
screwed spindle is a loose sleeve m', which carries at its lower end two pius
that enter pin holes made in the pattern at opposite sides of its central tapped
hole.
The sleeve of each screwed spindle is slotted longitudinally to receive a pin m²,
which is made fast to the screwed spindle. This piu serves also by means of a
rebate at the bottom of the slot of the sleeve to hold up the sleeve out of action
or clear of the pattern. When however the sleeve is dropped so that the pins at
its lower end enter the pin holes in the pattern, the pin m² will, as its spindle is
rotated, act as a driver and carry round the sleeve m', and thus ensure the rising
of the screwed pattern at the same rate of the mould; the spindle when turned
rises in its bearings.
Keyed to the upper end of each spindle is a chain wheel m³ for receiving a
driving chain m³, which passes around all the chain wheels and receives a
travelling motion from one of them, or from an additional chain wheel, as at
m³, Fig. 11. This chain wheel constitutes the driver, and is mounted on a screw
situate immediately above the runner hole, and is furnished with a handle for
turning it.
This apparatus is applied, as shewn at Fig. 10,to the half mould after the same has
been consolidated by pressing and drying, and when properly adjusted the screwed
spindles m, standing immediately over their respective patterns, will be caused by
the rotation of the chain wheels to descend and take hold of the screw patterns.
Before however the spindles make their descent their sleeves m³ must .be raised
to the dotted position of Fig. 10; when the screw spindles have taken a firm hold
of their patterns the sleeves are to be dropped to the drawn position of Fig. 10,
and the reverse turning of the screwed spindles will by reason of the engagement
of the sleeves with their respective patterns cause the patterns to rise simultaneously
out of the mould, as above explained.
When the two half moulds are placed together, as shewn at Fig. 9, the admis-
sion of molten metal thereto will produce headed bolts cast in one piece, as shewn
at Fig. 12.
From the foregoing it will be understood how a variety of screws and screwed
articles may be produced according to my Invention; Figs. 2, Sheet III., shew

page_text: the patterns for a square headed gimlet-pointed screw, the moulding of which will
be carried on in precisely the same manner as that explained with respect to the
screw bolt.
Figures 3 and 4 shew two forms of screw bolt suitable for use in connection
with railway fish plates. In both of these the neck of the screw is provided
with fins or feathers which prevent the turning of the bolt when it is fitted in
place.
The heads of these bolts will be moulded precisely like the head of the screw
bolt shewn at Fig. 12, Sheet I., but special patterns will be required for producing
the finned necks. The neck of the screw, Fig. 3, is square, and two of its flat sides
are provided with fins. The pattern for this finned neck is made separate from the
screwed stem. This pattern neck is shewn at Fig. 5 as drawn from the mould,
the screwed stem being still in the sand. The square neck is drilled through the
centre (see the plan view, Fig. 6) to receive a turned down portion of the screwed
stem, and tapped holes are made in the upper ends of the fins to receive rods for
drawing them out of the mould. The screwed stem will be removed from the
mould in the manner above described, and it is therefore furnished with a central
fapped hole and pin holes on opposite sides thereof for the application of the
withdrawing tool. In preparing the pattern for moulding the screw bolt, shewn
at Fig. 4, I form the neck in one piece with the screw stem, and form dovetail
grooves on opposite sides of the stem to receive detached fins, as shewn in the plan
view, Fig. 7. These fins are provided with tapped holes to receive a drawing rod
for removing them from the mould, Fig. 8, after the mould has been pressed and
hardened, as already explained.
When the fins are withdrawn the screw stem can then be raised out of the mould
by the screw withdrawing tool.
Figures 9 shew the pattern for moulding screwed glands for piston rods; this
pattern is in two parts, and each part is formed with a print, the print for the
head piece rising up in the centre of the cup, and the print for the screwed piece
constituting a short stem at the bottom of the screwed piece. This screwed piece it
will be seen is hollow, and formed with an internal thread and pin holes to provide
for its withdrawal from the sand mould; Fig. 10 shews in section the two half
moulds brought together and a cylindrical core inserted in place, its diameter
corresponding with the prints of the patterns. This core serves to form the
central hole in the casting, and it will be made in the same manner as the core
for the nut, the compressing dies being in this instance plain instead of threaded
dies.
Having now explained my Invention I wish it to be understood that under the
above in part recited Letters Patent I claim,-
First. Casting screws, screw bolts, nuts, and other threaded articles in moulds
prepared in the manner above explained, whereby such articles may be produced
equal to those formed by cutting tools and dies.
Secondly. The means above described for forming the cores for screw nuts,
screwed collars, glands, and such like articles.
Thirdly. The tool above described with reference to Figures 10 and 11. Sheet I.
of the Drawings, for withdrawing the screwed patterns from their mould.
In witness whereof, I, the said James Mackintire, have hereunto set my hand
and seal, the Twenty eighth day of September, in the year of our Lord
One thousand eight hundred and eighty one.
JAMES MACKINTIRE. (L.S.)