IMPROVEMENTS IN THE CONSTRUCTION OF CORE BARS
Year: 1859

page_text: LETTERS PATENT to Henry Cochrane, of Middlesbro'-on-Tees, Engineer,
for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF CORE BARS."
Sealed the 22nd May 1860, and dated the 30th December 1859.
PROVISIONAL SPECIFICATION left by the said Henry Cochrane at tho
Office of the Commissioners of Patents, with his Petition, on the
30th December 1859.
I, HENRY COCHRANE, of Middlesbro'-on-Tees, Engineer, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF CORE
BARS," to be as follows:-
This Invention has for its object improvements in the construction of core
bars. For these purposes a square internal tube is used, rendered as light as
may be by having parts of the sides removed; at one end this tube has a screw
applied thereto, the outer end of which is formed into an axis, the other end of
this tube has applied to it an axis, on which two axes the coro bar can be
caused to revolve in suitable bearings when applying loam to the exterior. On
the screw there is a screw nut, which can be rotated on the screw by bars in
the manner of a capstan head or otherwise. On the outside of the square tube
there are four sections of a cylinder, which when expanded to the full extent
leave spaces between them which are covered by strips or fillets of sheet metal,
in order to prevent the loam passing into the interior. These sections of
cylinders are retained together by tie bolts or rods, which by their heads and
nuts at their ends prevent the sections of a cylinder being moved out too far.
There are recesses formed in the sections to receive the heads and nuts of the
tie rods.

page_text: At one end the sections are formed with a transverse groove on their interior
surfaces into which a circular disc is received, and through the centre of which
the neck or axis at one end of the square tube passes. The other end of each
section is formed with an internal projection or flange, which enters a groove
formed around the screw nut; hence when the screw nut is turned the square
tube will be moved from one end, and towards the other end, according as the nut
is turned in one direction or the other. The interior surface of each section is
formed with internal longitudinal ribs, and the exterior surface of each of the
sides of the square tube is formed with longitudinal ribs, and it is by means of
these ribs that the interior tube is prevented turning. Inclines are formed on the
interior of the sections and on the exterior of the square tube, by which, when
the latter is moved longitudinally within the sections of the cylinder, the sections
of the cylinder will be expanded or allowed to come together, according as the
screw nut is moved in one direction or the other. When the core bar is in an
expanded state, it is coated with loam, and is used as a core in the ordinary
When the casting has been made thereon, the screw nut is to be
turned in such manner as to allow the sections to come together.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Cochrane in the Great Seal Patent Office on the
29th June 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, Henry-
COCHRANE, of Middlesbro'-on-Tees, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of December, in the year of our Lord
One thousand eight hundred and fifty-nine, and in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Cochrane, Her special licence that I, the said Henry Cochrane;
my executors, administrators, and assigns, or such others as I, the said.
Henry Cochrane, 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 THE
CONSTRUCTION OF CORE BARS," upon the condition (amongst others) that I, the
said Henry Cochrane, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should partieularly

page_text: 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 Henry Cochrane, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say::
This Invention has for its object improvements in the construction of core
bars. For these purposes a square internal tube is used, rendered as light as
may be by having parts of the sides removed; at one end this tube has a screw
applied thereto, the outer end of which is formed into an axis; the other end of
this tube has applied to it an axis, on which two axes the core bar can be caused
to revolve in suitable bearings when applying loam to the exterior. On the
screw there is a screw nut, which can be rotated on the screw by bars in the
manner of a capstan head or otherwise. On the outside of the square tube
there are four sections of a cylinder, which when expanded to the full extent
leave spaces between them, which are covered by strips or fillets of sheet metal
in order to prevent the loam passing into the interior. These sections of
cylinders are retained together by tie bolts or rods, which by their heads and
nuts at their ends prevent the sections of a cylinder being moved out too far.
There are recesses formed in the sections to receive the heads and nuts of the
tie rods.
At one end the sections are formed with a transverse groove on their
interior surfaces into which a circular disc is received, and through the centre
of which the neck or axis at one end of the square tube passes. The other
end of each section is formed with an internal projection or flange, which
enters a groove formed around the screw nut; hence when the screw nut is turned
the square tube will be moved from one end and towards the other end; according
as the nut is turned in one direction or the other. The interior surface of each
section is formed with internal longitudinal ribs, and the exterior surface of
each of the sides of the square tube is formed with longitudinal ribs, and it is
by means of these ribs that the interior tube is prevented turning: Inclines
are formed on the interior of the sections, and on the exterior of the square
tube, by which, when the latter is moved longitudinally within the sections
of the cylinder, the sections of the cylinder will be expanded or allowed to
come together according as the screw nut is moved in one direction or the
other. When the core bar is in an expanded state it is coated with loam, and
is used as a core in the ordinary manner. When the casting has been made,

page_text: thereon, the screw nut is to be turned in such manner as to allow the sections
to come together.
In the accompanying Drawing are Figures, which, with the aid of the
description herein-after contained, shew how my said Invention may be
performed. -
Figure 1 is a longitudinal section of a core bar constructed according to my
Invention; Figure 2 is a plan of the top end; Figure 3 is a transverse section
of the same at the line 1, 2, in Figure 1; Figure 4' is a section at the line
3, 4, in Figure 1; Figure 5 is a section at the line 5, 6, in Figure 1; Figure 6
is a plan of the bottom end of the core bar; Figures 2, 3, 4, 5, and 6 are
drawn to a larger scale than Figure 1. The same letters refer to similar parts
in each Figure.
The exterior of the core bar is divided into four segments A, A, A; A. The
edges of these segments are made to overlap each other, or have pieces of plate
iron a, a, attached to one edge of each segment, and covering the space between
it and the next segment. B is a tube which is made of a square sectional
form, its four sides corresponding with the four segments A. Long holes or
slots are made in the sides of this tube to lighten it; C is a pin or spindle fixed
into the lower end of the tube B; D is a screw fixed into the top of the
tube B. This screw and the spindle C serve to support the core bar when it
is being covered with loam; E is a disc or boss, the centre of which forms a
nut which is screwed on the screw D.
The top ends of the segments A are made with flanges b which enter a
groove in the nut E. They are thus kept in their proper positions longitudi-
nally, while at the same time they are free to expand and contract in diameter.
The lower ends of the segments A may be controlled in a similar manner or
they may be made with grooves c, c, embracing the edge of a disc F, through
which the spindle C slides freely, or they may be made without the disc as
herein-after described. The top ends of the segments may also be made with
two flanges forming a groove which embraces the edge of the disc E, instead
of entering a groove in the disc. Each segment A has two ribs d, d, on its
interior, which are guided laterally by two ribs e, e, on the corresponding side
of the tube B. The ribs d, d, have inclined projections at intervals which
are acted on by other inclines f, f, on the tube B, so that by moving the tube
endways in one direction those inclines force out the ribs d, d, and segments A,
and thus expand the core bar, and by moving the tube B in the opposite
direction these inclines allow the bar to collapse. These motions are commu-
nicated to the tube B, by turning the nut E, in either direction.
In order to
retain the segments A in their proper position and to prevent their expanding

page_text: to too large a diameter, I apply transverse bolts and nuts G, G, to connect
opposite segments. The segments A are cast or made with recesses deep enough
to receive the nuts and heads of the bolts and to allow for the required expand-
ing or collapsing motion. These recesses are covered with small iron plates g, g,
secured by four small screws or otherwise to prevent the entrance of sand or
loam. The flanges at one or both ends of the segments are made with vent
holes as shewn in Figure 2, and the segments are perforated with holes for
the escape of hot air, steam, or gas during the operation of casting.
The mode of using this core bar is as follows:-The nut E is turned by a
lever or spanner until the tube B is forced down and pushes out all the
segments A, A, to the full diameter, at which point their further expansion is
arrested by the bolts G, G. The core bar is then supported by the spindle
C and screw D, and covered with loam in the ordinary manner, and dried and
placed in the mould which may be that of a pipe or column or other hollow
article of cylindrical or nearly cylindrical form in the interior. The melted
cast iron or other metal is then run into the space between the coro, and the
mould; when the metal has solidified, the nut E is turned round so as to draw
back the tube B, and thus allow the segments A, A, to collapse. The core bar.
can then be drawn out and the loam is broken out and removed from the
casting as usual. The core bar is again expanded by turning the nut E, and
a fresh covering of loam is applied and so on.
Figure 7 is a longitudinal section of another core bar constructed according
to my Invention and differing very slightly from that shewn in the previous
Figures; Figure 8 is a plan of the top end; Figure 9 is a transverse section
at the line 1, 2, in Figure 7; Figures 10 and 11, are sections at the lines 3, 4
and 5, 6, respectively, in Figure 7%; Figure 12 is a plan of the bottom end;
Figures 8, 9, 10, 11, and 12 are drawn to a larger scale than Figure 7.
As cast-iron pipes are frequently cast in a perpendicular position, I have
described one end of the core bar as the top end, and the other as the bottom
end, but the positions of the ends may be reversed, or the bar may be used in
a horizontal or inclined position if desired. The segments A, A, are similar
to those in the core bar shewn in Figure 1, except that two opposite segments
are made to lap over the other two, and are cast of the required form instead
of having plates of wrought iron attached to them. The lower ends of the
segments are not controlled by a disc or groove as their longitudinal position
is controlled by their upper ends or flanges 6 entering the groove in the nut E,
and they are prevented from expanding beyond the proper point by the
transverse bolts G. The other parts are similar to those similarly marked
in Figures 1, 2, 3, 4, 5, and 6.
.

page_text: I have described my improved core bar as made with a square internal
tube, and with four sections or segments of a cylinder, because I deem that
to be the best and most economical mode of construction, but the shape of the
internal tube may be varied in any convenient manner, and the external
cylinder may, if preferred be divided into any other suitable number of
segments.
Having now-described the nature of the said Invention, and in what manner
the same is to be performed, I wish it to be understood that I do not claim
generally the constructing core bars with segments capable of being expanded
and collapsed, and that I do not claim any of the mechanical elements or
parts shewn in any of the above-mentioned Figures or above described, separate
or apart from the application and combination thereof, in the formation of
my improved core bars; and that what I do claim is constructing a core bar
having the segments of an external cylinder mounted upon or attached to an
internal tube with parallel inclines and guides for expanding the segments,
with radial regulating bolts or screws, having their heads or nuts, or both,
placed in recesses in the segments for limiting the expansion of the segments,
and each segment furnished with a groove or flange at one end, fitting upon
or into a projection or groove in the nut at one end of the internal tube for
the purpose of preventing longitudinal motion of the segments as herein-before
described.
In witness whereof, I, the said Henry Cochrane, have hereunto set my
and seal, this Eleventh day. of Junc, in the year of our Lord One
thousand eight hundred and sixty.
HENRY COCHRANE. (L.S.)