DESCOL Manufacture of Cast Metal Pipes and in Apparatus therefor.
Year: 1886

page_text: Date of Application, 26th May, 1886.
Complete Left, 26th Feb., 1887.
Complete Accepted, 29th Mar., 1887.
DESCOL
Manufacture of Cast Metal Pipes and in Apparatus therefor.
I, GEORGE FREDERICK REDFERN, of the General Patent Office, No. 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent, do hereby declare the nature of
this invention to be as follows:-
This invention relates to mechanically compressing sand cores for the manufacture
of cast iron pipes of all kinds and to the moulds or blocks for the manufacture of
conduit or descending pipes cast or moulded in a vertical position.
The improved machine for manufacturing vertical sand cores for cast iron pipes
consists of a large square cast iron bed plate which serves as a foundation for the
machine and can be provided with wheels adapted to run upon rails. The apparatus
may be thus arranged to be either fixed or moveable. The said plate is centrally
provided with a perforated boss formed integrally therewith and into which enters the
pivot of a turntable placed immediately above it. In order to compress sand for pipes
of great length having for example a length of from three to four meters, the core
boxes or moulds are mounted to oscillate upon the turntable and their lower ends
project into a pit or trench. In order to assist the oscillating motion caused by
journals placed upon one half of the length of the box or mould, the turn-table is
provided with an opening allowing the box or mould to assume a horizontal position at
a level slightly above that of the said turntable, in which case the foundation plate
placed upon rails at the bottom of the trench carries a pivot sufficiently high for the
turntable to be always maintained at its proper distance from the level of the ground
in the works. The core boxes or moulds can oscillate in the direction of a radius or
normally to such radius. A turntable is provided of sufficient size to receive thereon
in a vertical position at least three core boxes or moulds as near as possible to its outer
periphery. This turntable moves upon fixed rollers secured to the bed plate and is

page_text: .
provided centrally with an opening equal in size to that of the bed plate which opening
is for the purpose of receiving the pivot hereinafter described.
When operating in respect of pipes of great length whether in trenches or pits, the
turntable does not move upon rollers and its pivot is not the same as above stated, but
its construction is such that its rotary motion takes place in a similar manner to that
of railway cranes, the axis of which is placed in the ground at a considerable depth.
A certain number of rotating plates or trays or small turntables are provided placed
so as to exert only a small amount of friction upon the large turn table.
Eacli plate
serves to carry a core box or mould fixed thereon, by means of hinges so as to enable
the two parts to be opened.
The axes of these plates traversing the turntable should project sufficiently far
below in order to allow of mounting thereon a bevil wheel which is set in motion by
two elliptical or eccentric wheels keyed in such a manner that they may at a certain
period of their motion reduce the speed of rotation of the core box or mould and at
another period that is to say at a diametrically opposite period increase the speed of the
box. These means are used for pieces of large diameter as the rammer can only have
a single smooth rod.
When the core-box or mould is fixed, that is to say, is not
subjected to a rotary motion, the rammers used are constructed according to the
diameter of the pipe patterns, sometimes they may be formed of a soldered ring
provided with only one smooth rod, or a soldered ring provided with two smooth rods.
During an operation the turning plates or trays are disengaged, keyed and fixed by
means of stop bolts. The core boxes or moulds have their lower ends hinged to trays.
These boxes or moulds can and should be easily changed according to the diameters of
the pipes requiring to be nianufactured. The hinges of the bottom of the boxes
should therefore be connected with those of the trays or plates.
A vertical shaft consisting of a hollow cast iron pipe is arranged so as to be fixed
in the bed plate and serving as a centre for the turntable; this shaft carries at its
upper end a pulley frame and a grooved pulley. This frame which produces a very
small amount of friction is capable of turning in all directions and the grooved pulley
which it guides has a chain one end of which is passed into the hollow pipe and
hooked to a cylindrical weight while the other end of the chain is hooked to the upper
part of the core box or mould, so that as the box is moved upon its hinges the hollow
counter-weight loaded with lead counterbalances the same and enables the attendant
to operate the core box or mould without effort and without producing shocks. In
the case of pipes of great length this arrangement is not required as it ceases to
answer the purpose; the box is then hinged by its journals and equilibrates itself. In
the first case the counter weight can be advantageously replaced by a single acting
piston serving as an equilibrating medium by means of water or compressed air and
the hollow tube of which serves as a cylinder. Two cast iron pillars of suitable
height are fixed upon the bed plate and serve as a fulcrum for the mechanism which
effects the compression of the sand in the core box or mould. These two pillars
situated at a suitable distance from one another are cylindrical and may be turned
upon a certain length of their upper part. The said pillars are connected by tie bars,
the ends of which are bored out to allow of them sliding with slight friction, that is
to say, to allow of altering their heights according to the length of the cores to be
compressed, such alteration being effected by a counterweight, set screw or rack. To
the upper end of the said pillars is fixed the driving mechanism. Two carriages slide
with a very small amount of friction in grooves formed in supports. These carriages
carry four bearings upon which rest the horizontal axes of the smoothed cylinders
provided with cams and which are vertically divided at an equal distance from the axes
of the two cam-carrying cylinders arranged in a horizontal position and connected by
a hinge at their upper part and fixed by a bolt at their lower part. This division or
cutting has for object to effect the separation of the horizontal cylinders which
facilitates the changing of the rammers at each change of pattern. A set screw fixed
to the tie bars causes the carriages to move forward or backward when a rammer with
single rod is being used immediately after a rammer provided with two rods. When
the latter rammers are being used the space between two horizontal cylinders should

page_text: have for its axis the perpendicular serving also as an axis for the core box or mould,
whereas when the former rammers are employed the distance between the axis of the
space between the cylinders and the axis of the core should be regulated according to
the diameter of the pipe to be manufactured. The rammers are of wood or metal
and have a smooth metal rod of sufficient length to be conducted and guided by the
smooth cam-carrying cylinders. There should be therefore as many patterns and
forms of rammers as there are patterns of pipes. Some of these rammers have the
shape of ladles being solid or hollow and having a single rod, others are formed at
their base of welded iron of annular, oval or square shape and may be provided with
one or two rods. A series of two or four cylinders is employed each having gearing
at one of their ends and superposed two by two; one cylinder of each horizontal row
of two is slightly cam-shaped, the other cylinder being perfectly cylindrical. Each
row of horizontal cylinders rotates in a reverse direction to that of the next horizontal
row, The distance separating the outer periphery of these cylinders should be such.
that the rods of the rainmers shall be sufficiently pressed between the cam of the first
cylinder and the outer surface of the second cylinder. This pressure should be
sufficient to produce an elevation of the rammer equal to the development of the are
of the cam.
When the rammer rod has reached the extremity of the arc or arched
portion of the cam-shaped cylinder, (where four cylinders are employed) it should be
operated in a reverse direction to the above by the first cam of the first cylinder
belonging to the second series of two horizontal cylinders, in such a manner as to
produce an increase of-speed by the fall of the rammer which causes a shock, and
before the rammer rod is again raised by the first cam-shaped cylinder of the second
cam of the second cylinder which has a very short arc, a compressing motion is
imparted at the very moment when the shock of the rammer is produced upon the
sand core, that is to say, the operations are effected in the same manner as when a
workman effects them by hand. In order to obtain such a result, the two cylinders
provided with cams should be, on account of their gearings engaging with one
another, keyed upon their shafts.
The result of these combined motions is that as fast as the sand is introduced in the
core box or mould, the rammer ascends automatically in proportion to the amount of
sand introduced during its ascending motion until finally the core box being filled, the
sand-filler or feeder by means of a special combination stops automatically and the
rammer descends and completes the compression of the head of the core as when
effected by hand. The operation of these cylinders is of the highest importance and
constitutes the chief feature of this invention, they can be made of wood, metal or any
suitable composition of sufficient resistance smooth or grooved partially or entirely
covered with leather, india-rubber, gutta-percha or the like.
When the cylinder or cylinders is or are covered with substances of the kind above
mentioned and of sufficient thickness, an extra layer of suitable size of such material
will suffice to form the required cam. When this coating is worn out and ceases to
operate, a fresh coating can be substituted therefor, the apparatus being thus in
proper order and provided with a fresh cam. In some cases two horizontal cylinders
placed and arranged in the manner above described are sufficient for causing the
rammer to exert the required pressure upon the sand core; guides however are
indispensable in such cases, notwithstanding the grooves with which the said cylinders
may be provided. When four cylinders are employed the two cam-carrying cylinders
should be placed diagonally opposite one another so as to counteract the pushing
motion of the rammer rod, these cylinders being set in motion by the motor of the
apparatus by means of driving belts. A sand feeder or filler is fixed to the cross ties
of the two pillars and consists of a wooden or sheet iron body having its lower end
rectangular and arranged so that a cylinder can be adapted thereto round which move
metal or wooden buckets at a speed proportionate to that of the rammer and regularly
delivering the sand in the core box or mould. A receptacle for sand of wood, sheet
or cast iron is arranged in any suitable manner upon the bed plate, the bottom of
which is of a semi-cylindrical form. This receptacle contains a helix with several
hreads to which a very slow rotary motion is imparted but sufficient to bring into the

page_text: receiver of a bucket chain the necessary quantity of sand for filling each bucket on
its passage. The bucket chain carries the sand from the receptacle and into the
feeding hopper. An endless belt or its equivalent for the transmission of power
passes over two pulleys at any suitable point of its course and underneath a third
pulley which acts as a tension pulley. These three pullies may be grooved or flat
and are sufficiently covered by the band in order to prevent slipping; they transmit
motion to three shafts and by means of belts set the apparatus in operation. Instead
of three pullies only two can be employed but they should not be placed in the same
plane one having to be sufficiently far below the other to allow the belt or the like to
grip their peripheries in such a manner that no slipping takes place when the cylinders
and the rest of the mechanism are set in motion.
As regards the mode of adapting the machine it should form an integral part with
the principal crane, or with a special intermediate crane to which the principal crane
would impart motion.
Description of the operation:-The machine is constructed in such a manner that
there is not a moment lost from the beginning to the end of an operation and from the
manufacture of the core or pipe to the removal of the same and the preparation of
the next one; only one person is required to attend to the machine. It must be well
understood that this machine can only press straight cores or pipes, that is to say,
pipes without curves or joints. As above mentioned, from the way in which the core
boxes or moulds are placed upon the turn table having a circular continuous
intermittent motion, each core box or mould passes successively under the apparatus
having cam carrying and plain cylinders and provided with the rammer serving to
produce the compression of the sand core. For the compression of exterior cases or
moulds for pipes, the operation takes place in a reverse manner to the above, the
apparatus provided with cylinders being movable and running upon a circular
railway. In this case the apparatus is guided by the crane employed and passes
successively above each vertical mould in order to effect the compression of the
sand.
In order to properly manufacture a core and consequently a mould the sand should
be well rammed at the parts adjacent to the core shaft and especially in that part,
which has to be placed in the lower part of the mould so that thorough compactness
may be obtained in order to avoid any split and to prevent portions from becoming
detached from the core shaft. With regard to the mould it is sufficient that the
sand should be as evenly compressed as possible particularly along the sides of
the frame.
The sand should be introduced into the core box or mould or into the frame as
regularly as possible and proportionately to the speed of the rammer which is obtained
by means of the feeder and regulator.
Datel the 10th doir of October 1886

page_text: Manufacture of Cast Metal Pipes and in Apparatus therefor.
I GEORGE FREDERICK REDFERN, of the General Patent Office, No. 4 South Street,
Finsbury, in the county of Middlesex, Patent Agent do hereby declare the nature of
this invention (a communication from abroad by Jean Nicolas Marcel Millot, of Noix
aux Forges, in the republic of France, Mechanical Engineer) and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement:
―
This invention relates to mechanically compressing sand cores for the manufacture
of cast iron pipes of all kinds and to the moulds or blocks for the manufacture of con-
duit or descending pipes cast or moulded in a vertical position.
In order to enable the invention. to be fully understood I will describe how it can
with advantage be carried into practical effect by reference to the accompanying
drawing in which figure 1 is a longitudinal sectional elevation of an apparatus
for mechanically compressing sand cores and moulds used in the manufacture
of cast metal pipes according to this invention. Figure 2 is a front elevation of
the same; figure 3 is a sectional view and plan of an arrangement suitable for pipes
of from three to four meters in length figure 4 represents the arrangement for
transmitting motion figure 5 is a sectional plan of figure 2; figures 6 and 7, arc
detached views of parts of the apparatus shewn in figures 1 to 3 drawn to a larger
scale.
The improved machine for manufacturing vertical sand cores for cast iron pipes
consists of a large square cast iron bed plate A, which serves as a foundation for the
machine and can be provided with wheels adapted to run upon rails. The apparatus
may be thus arranged to be either fixed or imoveable. The said plate is centrally
provided with a perforated boss formed integrally therewith and into which enters the
pivot of a turntable placed immediately above it. In order to compress sand for pipes
of great length having for example a length of from three to four metres, the core
boxes or moulds are mounted to oscillate upon the turntable and their lower ends
project into a pit or trench. In order to assist the oscillating motion caused by journals
placed upon one half of the length of the box or mould, the turn-table is provided
with an opening allowing the box or mould to assume a horizontal position at a level
slightly above that of the said turntable in which case the foundation plate placed
upon rails at the bottom of the trench carriesa pivot sufficiently high for the turn-table
to be always maintained at its proper distance from the level of the ground in the

page_text: works. The core boxes or moulds can oscillate in the direction of a radius or normally
to such radius, as illustrated at B and B¹, in figure 3. A turn-table C is provided of
sufficient size to receive thereon in a vertical position at least three core boxes or
moulds as near as possible to its outer periphery. This turn-table moves upon fixed
rollers secured to the bed plate and is provided centrally with an opening equal in
size to that of the bed plate which opening is for the purpose of receiving the pivot
hereinafter described. When operating in respect of pipes of great length whether in
trenches or pits, the turn-table does not move upon rollers and its pivot is not the
same as above stated, but its construction is such that its rotary motion takes place in
a similar manner to that of railway cranes the axis of which is placed in the ground
at a considerable depth.
A certain number of rotating plates or trays D or small turn-tables are provided,
-placed so as to exert only a small amount of friction upon the large turn-table. Each
plate serves to carry a core box or mould fixed thereon by means of hinges so as to
enable the two parts to be opened. The axes of these plates traversing the turn-table
should project sufficiently far below in order to allow of mounting thereon a bevil
wheel which is set in motion by two elliptical or eccentric wheels keyed in such a
manner that they may at a certain period of their motion reduce the speed of rotation
of the core box or mould and at another period that is to say at a diametrically
opposite period increase the speed of the box. These means are used for pieces of
large diameter as the rammer can only have a single smooth rod.
When the core
box or mould is fixed, that is to say, is not subjected to a rotary motion, the rammers
used are constructed according to the diameter of the pipe patterns, sometimes they may
be formed of a soldered ring provided with only one smooth rod or a soldered ring
provided with two smooth rods. During an operation the turning plates or trays are
disengaged, keyed and fixed by means of stop bolts. The core boxes or moulds E,
have their lower ends hinged to the trays D. These boxes or moulds can and should
be easily changed according to the diameters of the pipes requiring to be manufactured.
The hinges of the bottom of the boxes should therefore be connected with those of
the trays or plates.
al
A vertical shaft F, consisting of a hollow cast iron pipe is arranged so as to be
fixed in the bed plate and serving as a centre for the turn-table; this shaft carries at
its upper end a pulley frame and a grooved pulley. This frame which produces
very small amount of friction is capable of turning in all directions and the grooved
pulley which it guides has a chain, one end of which is passed into the hollow pipe
and hooked to a cylindrical weight while the other end of the chain is hooked to the
upper part of the core box or mould, so that as the box is moved upon its hinges the
hollow counter weight loaded with lead counterbalances the same and enables the
attendant to operate the core box or mould without effort and without producing
shocks. In the case of pipes of great length this arrangement is not required as it
ceases to answer the purpose; the box is then hinged by its journals and equilibrates
itself. In the first case the counter weight can be advantageously replaced by a
single acting piston serving as an equilibrating medium by means of water or
compressed air and the hollow tube of which serves as a cylinder. Two cast iron
pillars G, of suitable height are fixed upon the bed plate and serve as a fulcrum for
the mechanism which effects the compression of the sand in the core box or mould.
These two pillars situated at a suitable distance from one another are cylindrical and
may be turned upon a certain length of their upper part. The said pillars are
connected by tie bars H, the ends of which are bored out to allow of them sliding
with slight friction, that is to say, to allow of altering their heights according to the
length of the cores to be compressed, such alteration being effected by a counter-
weight, set screw or rack. To the upper end of the said pillars is fixed the driving
mechanism. Two carriages J, slide with a very small amount of friction in grooves
formed in supports K. These carriages carry four bearings upon which rest the
horizontal axes of the plain and cam-shaped cylinders L N and L, N, and are cut 5
vertically at an equal distance from the axes of two cylinders arranged in a horizontal

page_text: position and connected by a hinge at their upper part and fixed by a bolt at their
lower part. This division or cutting has for object to effect the separation of the
horizontal cylinders which facilitates the changing of the rammers at each change of
pattern. A set screw fixed to the tie bars causes the carriages to move forward or
backward when a rammer with single rod is being used immediately after a rammer
provided with two rods. When the latter rammers are being used the space between
two horizontal cylinders should have for its axis the perpendicular serving also as an
axis for the core box or mould, whereas, when the former rammers are employed the
distance between the axis of the space between the cylinders and the axis of the core
should be regulated according to the diameter of the pipe to be manufactured.
The rammers M, are of wood or metal and have a smooth metal rod of sufficient
length to be conducted and guided by the smooth cam-carrying cylinders. There
should be therefore as many patterns and forms of rammers as there are patterns
of pipes. Some of these rammers have the shape of ladles being solid or hollow and
having a single rod, others are formed at their base of welded iron of annular, oval
or square shape and may be provided with one or two rods. A series of two or four
cylinders is employed such as L, L, N, N2, each having gearing at one of their ends
and superposed two by two; one cylinder of each horizontal row of two is slightly
cam-shaped as shewn at L' and N¹ the other cylinder being perfectly cylindrical as
shewn at L and N. Each row of horizontal cylinders rotates in a reverse direction to
that of the next horizontal row. The distance separating the outer periphery of these
cylinders should be such that the rods of the rammers shall be sufficiently pressed
between the cam of the first cylinder and the outer surface of the second cylinder.
This pressure should be sufficient to produce an elevation of the rammer equal to the
development of the arc of the cam. When the rammer rod has reached the extremity
of the arc or arched portion of the cam-shaped cylinder (where four cylinders are
employed) it should be operated in a reverse direction to the above by the first cam of
the first cylinder belonging to the second series of two horizontal cylinders in such a
imanner as to produce an increase of speed by the fall of the rammer which causes a
shock, and before the rammer rod is again raised by the first cam-shaped cylinder of
the second cam of the second cylinder which has a very short arc, a compressing
motion is imparted at the very moment when the shock of the rammer is produced
upon the sand core, that is to say, the operations are effected in the same manner as
when a workman effects them by hand. In order to obtain such a result, the two
cylinders provided with cams should be, on account of their gearings engaging with
one another, keyed upon their shafts.
The result of these combined motions is that as fast as the sand is introduced in the
core box or mould, the rammer ascends automatically in proportion to the amount of
sand introduced during its ascending motion until finally the core box being filled, the
sand filler or feeder by means of a special combination stops automatically and the
rammer descends and completes the compression of the head of the core as when
effected by hand. The operation of these cylinders is of the highest importance and
constitutes the chief feature of this invention; they can be made of wood, metal or
any suitable composition of sufficient resistence smooth or grooved partially or
entirely covered with leather, india-rubber, gutta-percha, or the like.
When the cylinder or cylinders is or are covered with substances of the kind above
mentioned and of sufficient thickness, an extra layer of suitable size of such material
will suffice to form the required cam. When this coating is worn out and ceases to
operate, a fresh coating can be substituted therefor, the apparatus being thus in
proper order and provided with a fresh cam. In some cases two horizontal cylinders
placed and arranged in the manner above described are sufficient for causing the
rammer to exert the required pressure upon the sand core; guides however are in-
dispensable in such cases, notwithstanding the grooves with which the said cylinders
may be provided. When four cylinders are employed the two cam-carrying cylinders
should be placed diagonally opposite one another so as to counteract the pushing
motion of the rammer rod, these cylinders being set in motion by the motor of the

page_text: 4
apparatus by means of driving belts. A sand feeder or filler 0, (figure 1) is fixed to
the cross ties of the two pillars and consists of a wooden or sheet iron body having its
lower end rectangular and arranged so that a cylinder can be adapted thereto round
which move metal or wooden buckets at a speed proportionate to that of the rammer
and regularly delivering the sand in the core box or mould. A receptacle P, for sand
of wood, sheet or cast iron is arranged in any suitable manner upon the bed plate, the
bottom of which is of a semi-cylindrical form. This receptacle contains a helix with
several threads to which a very slow rotary motion is imparted but sufficient to bring
into the receiver of a bucket chain the necessary quantity of sand for filling each
bucket on its passage. The bucket chain Q, carries the sand from the receptacle and
into the feeding hopper. An endless belt R (figure 5) or its equivalent for the
transmission of power passes over two pulleys at any suitable point of its course and
underneath a third pulley which acts as a tension pulley. These three pulleys may be
grooved or flat and are sufficiently covered by the band in order to prevent slipping:
they transmit motion to three shafts and by means of bells set the apparatus in
operation. Instead of three pulleys only two can be employed but they should not be
placed in the same plane one having to be sufficiently far below the other to allow the
belt or the like to grip their peripheries in such a manner that no slipping takes place
when the cylinders and the rest of the mechanism are set in motion.
As regards the mode of adapting the machine it should form an integral part with
the principal crane, or with a special intermediate crane to which the principal crane
would impart motion.
Description of the operation:-The machine is constructed in such a manner that
there is not a moment lost from the beginning to the end of an operation and from the
manufacture of the core or pipe to the removal of the same and the preparation of the
next one; only one person is required to attend to the machine. It must be well
understood that this machine can only press straight cores or pipes, that is to say,
pipes without curves or joints. As above mentioned, from the way in which the core
boxes or moulds are placed upon the turn-table having a circular continuous inter-
mittent motion, each core box or mould passes successively under the apparatus having
cam carrying and plain cylinders and provided with the rammer serving to produce
the compression of the sand core. For the compression of exterior cases or moulds
for pipes, the operation takes place in a reverse manner to the above, the apparatus
provided with cylinders being movable and running upon a circular railway. In this
case the apparatus is guided by the crane employed and passes successively above each
vertical mould in order to effect the compression of the sand.
In order to properly manufacture a core and consequently a mould the sand should
be well rammed at the parts adjacent to the core shaft and especially in that part which
has to be placed in the lower part of the mould so that thorough compactness may be
obtained in order to avoid any split and to prevent portions from becoming detached
from the core shaft. With regard to the mould it is sufficient that the sand should
be as evenly compressed as possible particularly along the sides of the frame.
The sand should be introduced into the core box or mould or into the frame as
regularly as possible and proportionately to the speed of the rammer which is obtained
by means of the feeder and regulator.
In order to effect an equal distribution of the sand a distributing cylinder A¹
(figures 6 and 7) is employed provided with vanes or ribs and placed at a suitable
height and working in a sheet iron tube of rectangular section above which and joined
thereto is a hopper O¹, of any suitable form serving as a receptacle for the sand and
provided with a hinged regulator B, operated by a set screw Q¹, which serves to
regulate the opening through which the sand descends. The distributing cylinder A',
causes the sand to fall regularly into a tube K', of similar shape which sand is received
in a circular hopper C, fixed, hingewise to the frame of the apparatus. In this
hopper C, a distributing or spreading cylinder D¹, is rotated by means of a worm and
worm wheel M, PI; the cylinder D', is provided with four openings E¹, and with four
vanes or blades L', which take the sand at the outlet of the tube K, and spread it

page_text: regularly and uniformly over the whole interior periphery of a sheet iron cone N¹,
moveable in the direction of its height and varying in diameter at its smaller end
according to the size of the core boxes.
By this means the risk of the sand being incompletely pressed in parts is avoided
and the uniformity of the tube of the pipe is insured.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :-
1. The general arrangement and construction of the herein described apparatus for
compressing sand cores and moulds used in the manufacture of cast metal pipes.
2. The application of plain and cam shaped or grooved rollers or cylinders in any
suitable manner for actuating a rammer having a smooth rod by pressure and by
friction the said cylinders being coated upon their periphery or in grooves with leather,
india rubber, gutta percha or any other suitable material producing little friction upon
the smooth rods of the rammer, which rods may be of any suitable section to effect the
compression of the sand used for manufacturing cores or exterior cases for pipes
moulded or cast vertically.
D