IMPROVED CORE BAR FOR USE IN CASTING METAL PIPES OR CYLINDERS
Year: 1884

page_text: QUAIR LEIE SPECIFICATION.
I, ALFRED GEORGE BROOKES of the firm of Wm Brookes & Son of 55 Chancery
Lane in the County of Middlesox Fellow of the Institute of Patent Agents do
hereby declare the nature of my Invention for IMPROVED CORE BAR FOR USE IN
CASTING METAL PIPES OR CYLINDERS and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
When casting pipes or cylinders it is desirable that the core bar should be
capable of a reduction in size, in preference to its being wrapped with hay or
straw bands or such destructible material before being coated with loam, so as to
allow of its easy withdrawal from the casting, various efforts have been made but
hitherto, as far as I have been able to ascertain, only with partial success, the
object of my Invention is by simplicity and fewness of parts, to ensure a thoroughly
rigid core bar under all the strains it may be subjected to, constructed so that it
will make a truly round core, and to collapse so as to admit of its being easily
withdrawn after the casting of the said pipe or cylinder.
In carrying out my improvements the external part of the core bar is formed of
either two or three segments, each extending the length of the core bar, these
segments may be hinged together with ordinary butt hinges, but are preferred with
projecting pieces, which keep the segments in correct relation to each other, and
do not cause any friction when the core bar is required to collapse.
Inside the core bar there is a longitudinal key bar, one edge of which rests on a
number of distance pieces, which are fastened on the centre segment, the other
edge of the key bar almost fills the space which is left between the two larger
segments, on the sides of the key bar are a number of V shaped. wedges or keys
which fit into corresponding V shaped brackets on the inside of the two larger
segments, so that when the key bar is drawn in one direction the segments are
expanded into a thoroughly rigid position, and when the key bar is drawn in the
opposite direction the segments are allowed to collapse, sand or loan is applied to
give the correct form of the core, a number of stay bolts are passed through, the
core bar to retain the core bar from being expanded beyond its correct diameter,
•

page_text: But in order that the nature of my said Invention and the means adapted for
carrying the same into practical effect may be the better understood I will by the
aid of the accompanying Drawings proceed to describe the same more in detail.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 2 shew longitudinal views of a core bar constructed according to 5
my Invention, the left hand half of each view showing the core bar when expanded,
the right hand half showing the position of the key bar when drawn so as to allow
the segments to collapse. Figure 8 shows a section of a core bar when expanded.
Figure 4 shows an end view of the same. Figure 5 shows a section of a core bar
when collapsed. Figure 6 shows an arrangement with two segments for small 1
sizes. Figure 7 shows an enlarged section of the improved hinge which I prefer
to use.
In each of the Figures the same letter is employed to indicate corresponding
parts. The shell of the core bar consists of the two segments a. a. the segment b,
and one edge c¹ of the key bar c. The edges a' and 6 are kept in their correct 1
relation to each other by a number of hinges or projections d and which fit into
_corresponding recesses in the edge of the opposite segments, that is there are a
-number-of-hinges or projecting-pieces.d.on the edges 6 fitting into recesses on the
edges a¹, and an equal number of projecting pieces d' on the edges a' fitting into
recesses on the edges b'. I prefer these projections in the place of butt hinges, 2
because there is less friction, and for economy, and because they allow the segments
to be taken off and put on so very readily. c is a central key-bar extending the
-length-of-the-core-bar, on-each-side-of-c-are a number of wedges.c² V-shaped-on-the
edge, and tapered longitudinally, these wedges c fit into V shaped recessed
brackets a³ on the inside of segments a. These brackets and wedges being formed 2
V shape, tends to keep the core bar perfectly rigid when it is being turned on its
journals, while the core is being formed, also when the pressure of molten iron is
around the core during the casting of a pipe or cylinder.
On the inside of the segment b are a number of distance pieces e which support
the key-bar c on the parts c³ when the bar is expanded, and on the parts c when 3
the core bar is collapsed. The stay bolts fare to keep the segments aa from being
expanded beyond their correct diametor. When the key bar c is being drawn with
the wedges c³ into the brackets a. g is a short plate fixed so that when the core
bar is expanded one end will rest on the end of the shell of core bar, and the other
end on the key bar c this plate is screwed down by the nut gl so as to keep the 3
key bar in its correct position when the core bar is expanded, when it is required
to draw the key bar c to allow the core bar to collapse, the nut g¹ is unscrewed and
the plate g is moved into the position shown by the dotted lines on Figure 4, and
the key bar c is drawn into the position shown in the right haud portion of Figures
1 and 2 and in Figure 5. The key bar sliding parallel with the centre line of the 4
core bar until the wedges c¹ are out of the brackets a³ and then it recedes from the
centre, so as to leave a space between the two segments a a, to admit of the core
bar collapsing, the parts of the key bar c will then rest on the distance pieces e.
The portions support the weight of the shell of the coro bar, while it is being
withdrawn from the pipe which has been cast around it. To expand the core bar
the key bar c is drawn from the position where rests on the distance pieces e,
until the wedges c³ are opposite the brackets a³, the portion of the key bar c
between the parts c³ and c being inclined so as to give greater facility for drawing
the key bar o into its correct position, the key bar c is then drawn forward into
the position shown in Figures 3 and 4, and the left hand portions of Figures 1
and 2, the V shaped wedges and brackets being tapered longitudinally, the segments
are expanded so as to make the core bar perfectly rigid, and to enable a truly round
core to be formed upon it with loam or other suitable material. Hand H³ aro
journals or spindles for the support of the core bar on suitable bearings to enable
the coro bar to be turned while the core is being formed.
c

page_text: Figuro 7 also shows an arrangement with a hook and eye of which thero aro
four, one on each end of the joints a³ and b¹, to keep the segments a and b in their
correct relation when the core bar is collapsed. The core bar is vented to allow for
the escape of gas in the usual manner by vent holes.
By thus forming the core bar with several segments in the manner described,
greatly increased facility is obtained for the removal of the core bar from the
interior of the pipe which has been cast on it, the powerful expanding action of the
V shaped wedges when placed in the position shown on the accompanying Drawings
tending to make the core bar thoroughly rigid.
In reference to my said Invention and the means adapted for carrying the same
into practical effect I would have it understood that I do not confine myself to the
precise arrangement of parts herein described and shewn by the Drawings as the
same may be varied without departing from the peculiar character of my
Invention but
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declaro that what
I claim is:
The combination or arrangement of the segments a. a. b and c, with the
V shaped wedges and brackets, and the projecting pieces or hinges & and d' and
parts connected thereto, substantially as described for use in casting metal pipes or
cylinders.