IMPROVEMENTS IN MACHINERY FOR DRILLING THE SHELLS OF BOILERS."
Year: 1881

page_text: LETTERS PATENT to William Allan, of Sunderland, in the County of Durham,
for an Invention of "IMPROVEMENTS IN MACHINERY FOR DRILLING THE
SHELLS OF BOILERS."
PROVISIONAL SPECIFICATION left by the said William Allan at the
Office of the Commissioners of Patents on the 18th July 1881.
WILLIAM ALLAN, of Sunderland, in the County of Durham.
IN MACHINERY FOR DRILLING THE SHELLS OF BOILERS."
"IMPROVEMENTS
This Invention has for its object improvements in machinery for drilling the
shells of boilers.
A Patent was granted to me in the year 1875, No. 297, for a machine intended
to serve this purpose, and my present Invention consists in improvements on that
machine.
As formerly, I cause the cylindrical boiler shell to be erected in a vertical position
in the centre of a circular or ring bed, upon which moveable standards are mounted.
Each standard has a saddle upon it carrying a drill, and the saddle with the drill
can be moved up or down upon the standard so as to follow if required along a
vertical row of holes. By the movement of the standards around the circular
bed the drill can also be made to follow horizontally along a row of holes, passing
circumferentially around the boiler shell. The parts on each standard are driven
by a vertical axis passing along it, and formerly I had a steam engine or motor
mounted upon each standard. In place thereof I now employ endless cords to
drive the parts, the motor being at any convenient distance. I now carry the
boiler shell upon a bed plate mounted on the top of a central post or pivot, and
also supported near its periphery on rollers carried by the standards. The central
post or pivot has a pulley upon it mounted to revolve beneath the bed plate, and
this pulley is grooved to receive a number of endless cords. One of these grooves
receives the driving cord, and from each of the other grooves an endless cord is
led off to one of the standards, where it drives a pulley, which operating through
bevilled gear gives motion to the vertical shaft running along the standard, from
which the movements for the tool are derived.
In connection with these endless cords I apply adjustable pulleys to regulate
the tension.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Allan in the Great Seal Patent Office on the 17th
January 1882.
WILLIAM ALLAN, of Sunderland, in the County of Durham. "IMPROVEMENTS IN
MACHINERY FOR DRILLING THE SHELLS OF BOILERS."
This Invention has for its object improvements in machinery for drilling the
shells of boilers.
A Patent was granted to me in the year 1875, No. 297, for a machine intended
to serve this purpose, and my present Invention consists in improvements on that
machine.
As formerly, I cause the cylindrical boiler shell to be erected in a vertical
position in the centre of a circular or ring bed, upon which moveable standards
are mounted. Each standard has a saddle upon it carrying a drill, and the saddle
with the drill can be moved up or down upon the standard so as to follow if
required along.a vertical row of holes. By the movement of the standards around
the circular bed the drill can also be made to follow horizontally along a row of
holes passing circumferentially around the boiler shell. The parts ou each standard
are driven by a vertical axis passing along it, and formerly I had a steam engine
or motor mounted upon each standard. In place thereof I now employ endless
cords to drive the parts, the motor being at any convenient distance. I now carry
the boiler shell upon a bed plate mounted on the top of a central post or pivot,
and also supported near its periphery on rollers carried by the standards. The
central post or pivot has a pulley upon it mounted to revolve beneath the bed
plate, and this pulley is grooved to receive a number of endless cords. One of
these grooves receives the driving cord, and from each of the other grooves an
endless cord is led off to one of the standards, where it drives a pulley, which
operating through bevilled gear gives motion to the vertical shaft running along
the standards from which the movements for the tool are derived.
In connection with these endless cords I apply adjustable pulleys to regulate
the tension.
In order that my said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan, and Figure 2 is a vertical section of a machine constructed
according to my Invention. The figures indicate only so much of the machine as
is necessary for the clear explanation of the novel features.
a, a, is the circular guide ring or bed of the machine upon which the standards
b, b, b, are erected, and as heretofore they can be moved around upon the ring a,
and set in any position upon it. The drill saddles which the standards carry, and
which are moveable up and down upon the standards are seen at c, c; neither
they nor the drill spindles present any novel feature; d, d, are the vertical axes
by which the drills are driven, and I now give motion to these in the following
manner is a compound pulley capable of revolving freely on the centre post or
pivot. It is rotated by the driving cord g passing around it. h, h, are other
endless cords passing around the pulley e; there is one of these endless cords h for
each standard b. The cord in each case passes around a pulley on a vertical
axis i, which has its bearing upon the base of the standard. At the upper end
of each axis i is a bevelled wheel gearing into and driving a similar wheel j¹ on

page_text: an axis j, and this axis is by the pinions and d geared with the vertical axis d,
which as already mentioned passes up the standard, and as in previous machines
drives the drill spindles. There are pulleys k, k, for adjusting the tension of the
cords h, h, against which they are pressed by springs. 7 is a turn table bed plate
on which the boiler shell m which is to be drilled stands; this bed plate is further
supported by the small rollers n, n, upon the bases of the standards.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that
I claim my improved machinery for drilling the shells of boilers, in which the
axes d of the standards b which are moveable around the circular bed a are
driven by cords h passing around a central pulley e, substantially as described.
In witness whereof, I, the said William Allan, have hereunto set my hand
and seal, this Fifteenth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
WILLIAM ALLAN. (L.S.)