DOI Page / Citation link:
https://doi.org/10.11588/diglit.1401#0181
130
THE ILLUSTKATED EXHIBITOR.
€ty dtott Cxjiitiita 33nilitmg-No.iv.
BY CHARLES FOWLER,, JTJN.
Before proceeding to show how this great structure was actually reared, some of the mechanical contrivances
employed in producing its numerous parts remain to he noticed in continuation of our last article on this part of the
subject. .
In order to facilitate and forward the construction of the wrought iron trusses for the roof, machinery was employed
to punch and drill the numerous holes for rivets and holts in the wrought-iron bars of which the trusses were con-
structed ; this machinery, though not specially invented for the occasion, may be sufficiently novel to our readers to
interest them in a description, assisted by the views given. In order that the parts of all the trusses might exactly
correspond so as readily to fit together, a template or pattern was made for each part, with the holes for the rivets and
bolts cut out in the proper places; this being laid upon the iron bars previously cut to the requisite length, the places
for the rivet holes were marked with paint from those cut out of the template, and in this state the bars were taken to
the punching and drilling machines.
The punching machine consists of a very solid mass of cast iron, in the front face of which there are two
indentations, as shown in the engraving. In the lower of these the punching operation is performed, and in the upper
shears are fixed for cutting the ends of iron
bars ; at the back of this cast-iron stand, cogged
wheels, with a drum and fly wheel, are fixed,
by means of which the punch and shears are
set in motion. These work in a vertical
direction, being slowly moved up and down
with an irresistible force, the amount of which
the unpractised eye has no means of discover- O/. *,{
ing, as there is no blow or sudden operation, yi '
thus rendering the effect more striking. To
show that the force exerted is really very
great, it may be mentioned, that although the
punching of a hole scarcely occupies two or
three seconds, the iron bar becomes quite hot
from the effect of the pressure for even that
short time. In using this piece of machinery,
the iron bar is placed on a solid rest in such a
position that when the punch descends upon
it, the hole is cut out where the spot was
marked by the template. As soon as the
punch has passed through the bars, the ma-
chinery is so contrived that it begins to ascend,
during which time the workman re-arranges
the bar, and the operation is thus continually ths punching machine" and shears.
repeated. The action of the shears is precisely similar to that of the punch, and does not require, therefore, to be
specially described. The punching machine requires three men to work, or rather feed it, if the bars to be punched are
of any considerable length so as to require the ends to be supported; otherwise one alone is sufficient, and in the
course of a working day of ten hours about 3,000 holes can he punched out, though the number necessarily depends upon
the thickness of the bars.
The holes for flat-headed rivets were made by drilling, and the centre of each hole having been first marked on
the bar, it was taken to the drilling machine, a view of which is given. This consists of a solid cast iron stand, with
a small flat table at a convenient height on which to rest the bars ; over this is suspended the drilling point, working
in a collar vertically, and capable of being raised or lowered to suit the different thicknesses of iron that are brought
under its operation. The drill is worked by cogged wheels and a drum to connect them with the driving engine; a
much smaller amount of power is required in this case than to work the^punching machine, the process being gradual,
and therefore occupying much more time.
THE DRILLING MACHINE.
The drill is suspended from one end of a
lever, the other end having a counterpoise
weight so as to keep the drill up from the
table when not in use. This lever is con-
nected by a rod and crank with another near
the ground, one end of which is formed as a
tread to be worked by the foot of the ope-
rator. The workman, having arranged the
iron in the right position under the chill,
presses his foot upon the tread, thereby
raising the counterpoised end of the upper
lever and lowering the point of the drill,
which is of a spear-head form, down upon
the iron. The operation necessarily causes
a great heat from the friction between the
drill and the iron, and to prevent the point
from thus losing its hardness, it requires to
be frequently moistened during the opera-
tion ; to protect the point of the drill when
it has passed the bar, a piece of tough wood
is placed underneath the iron to be drilled.
It requires the same number of men to work
this machine as for the punching machine.
Both these pieces of machinery were worked
on the spot.
THE ILLUSTKATED EXHIBITOR.
€ty dtott Cxjiitiita 33nilitmg-No.iv.
BY CHARLES FOWLER,, JTJN.
Before proceeding to show how this great structure was actually reared, some of the mechanical contrivances
employed in producing its numerous parts remain to he noticed in continuation of our last article on this part of the
subject. .
In order to facilitate and forward the construction of the wrought iron trusses for the roof, machinery was employed
to punch and drill the numerous holes for rivets and holts in the wrought-iron bars of which the trusses were con-
structed ; this machinery, though not specially invented for the occasion, may be sufficiently novel to our readers to
interest them in a description, assisted by the views given. In order that the parts of all the trusses might exactly
correspond so as readily to fit together, a template or pattern was made for each part, with the holes for the rivets and
bolts cut out in the proper places; this being laid upon the iron bars previously cut to the requisite length, the places
for the rivet holes were marked with paint from those cut out of the template, and in this state the bars were taken to
the punching and drilling machines.
The punching machine consists of a very solid mass of cast iron, in the front face of which there are two
indentations, as shown in the engraving. In the lower of these the punching operation is performed, and in the upper
shears are fixed for cutting the ends of iron
bars ; at the back of this cast-iron stand, cogged
wheels, with a drum and fly wheel, are fixed,
by means of which the punch and shears are
set in motion. These work in a vertical
direction, being slowly moved up and down
with an irresistible force, the amount of which
the unpractised eye has no means of discover- O/. *,{
ing, as there is no blow or sudden operation, yi '
thus rendering the effect more striking. To
show that the force exerted is really very
great, it may be mentioned, that although the
punching of a hole scarcely occupies two or
three seconds, the iron bar becomes quite hot
from the effect of the pressure for even that
short time. In using this piece of machinery,
the iron bar is placed on a solid rest in such a
position that when the punch descends upon
it, the hole is cut out where the spot was
marked by the template. As soon as the
punch has passed through the bars, the ma-
chinery is so contrived that it begins to ascend,
during which time the workman re-arranges
the bar, and the operation is thus continually ths punching machine" and shears.
repeated. The action of the shears is precisely similar to that of the punch, and does not require, therefore, to be
specially described. The punching machine requires three men to work, or rather feed it, if the bars to be punched are
of any considerable length so as to require the ends to be supported; otherwise one alone is sufficient, and in the
course of a working day of ten hours about 3,000 holes can he punched out, though the number necessarily depends upon
the thickness of the bars.
The holes for flat-headed rivets were made by drilling, and the centre of each hole having been first marked on
the bar, it was taken to the drilling machine, a view of which is given. This consists of a solid cast iron stand, with
a small flat table at a convenient height on which to rest the bars ; over this is suspended the drilling point, working
in a collar vertically, and capable of being raised or lowered to suit the different thicknesses of iron that are brought
under its operation. The drill is worked by cogged wheels and a drum to connect them with the driving engine; a
much smaller amount of power is required in this case than to work the^punching machine, the process being gradual,
and therefore occupying much more time.
THE DRILLING MACHINE.
The drill is suspended from one end of a
lever, the other end having a counterpoise
weight so as to keep the drill up from the
table when not in use. This lever is con-
nected by a rod and crank with another near
the ground, one end of which is formed as a
tread to be worked by the foot of the ope-
rator. The workman, having arranged the
iron in the right position under the chill,
presses his foot upon the tread, thereby
raising the counterpoised end of the upper
lever and lowering the point of the drill,
which is of a spear-head form, down upon
the iron. The operation necessarily causes
a great heat from the friction between the
drill and the iron, and to prevent the point
from thus losing its hardness, it requires to
be frequently moistened during the opera-
tion ; to protect the point of the drill when
it has passed the bar, a piece of tough wood
is placed underneath the iron to be drilled.
It requires the same number of men to work
this machine as for the punching machine.
Both these pieces of machinery were worked
on the spot.