Mechanical Tube Scrubber.
Year: 1890

page_text: Date of Application, 31st Dec., 1890
Complete Specification Left, 26th Sept., 1891-Accepted, 31st Oct., 1891
PROVISIONAL SPECIFICATION.
Mechanical Tube Scrubber.
I, JOHN LAIDLAW, of 12 Bruce Road Pollokshields, North Britain, Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention has for its object the construction of apparatus to be actuated by
mechanical means wherewith to remove incrustation, soot, scale, or other deposit
from the interior of tubes such as are employed in the construction of steam boilers,
sugar liquor evaporators, condensers, and the like.
That portion of the apparatus which operates upon the material to be removed
from the interior of the tube is made up more or less in a manner similar to the
well known tube brushes and scrapers; but instead of being pushed by hand, and
being slightly larger than the internal diameter of the tube, it is slightly smaller,
and is caused to revolve by mechanical means; the axis of revolution coinciding
with the centre line or axis of the tube. In order to obtain the requisite pressure
of the brush or scraper it is divided into two or more sections longitudinally, which
are hinged near the axis on the longitudinal edges so that when the brush or scraper
is caused to revolve at a suitable speed the centrifugal action generated will cause
the section of the scrubber to press against the interior surface of the tube. The
construction is such as to allow of a certain size of scrubber serving to clean various
sizes of tubes larger than the smallest size for which a particular size of scrubber
is made; the expanding action due to its quick revolution causing the surface of
the brush to fill the tubes up to the limit of its expansion. This action likewise
allows of completely wearing out the whole of the wires or other substances of
which the scrubber is made. Instead of the sections being hinged they may be
constructed of flexible material or by a method of positive expansion which could
be adjusted before use or allowed to expand by centrifugal action. The head, or
brush, or scraper part of the scrubber is fixed on the end of a shaft slightly longer
than the length of tube to be cleaned, and this shaft is contained in a hollow tube
which serves as a support for the revolving shaft, and also provides the means for
the operator to handle the instrument and insert it into the tube which is to be
cleaned. A flexible shaft" of the well-known construction of suitable length and
driven by convenient power is attached to the shaft which is connected to the head
of the scrubber. When set in motion, the operator has only to push the scrubber
through the length of the tube, (the revolving of the scrubber materially assists
this operation, and as it may revolve about 500 revolutions per minute, the tube will
be found to be clean, however quickly the scrubber may be made to traverse the
length of the tube and be withdrawn.
Other well-known mechanical methods may be employed to communicate motion
to the end of the scrubber shaft, such as an arrangement of positive gearing mounted
on a suitable framework conveniently arranged to be moved into a position exactly
opposite the tube to be operated upon, and the mechanism might be so constructed.
as to perform the work automatically.
An electro-motor could also be attached directly to the end of scrubber shaft,.
and the electric current led thereto by wires which would be loose and flexible.
Dated this 30th day of December 1890.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.

page_text: Mechanical Tube Scrubber.
I, JOHN LAIDLAW, of 12 Bruce Road, Pollokshields, North Britain, Engineer,
do hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention has for its object the construction of apparatus to be actuated by
mechanical means wherewith to remove incrustation, soot, scale, or other deposit
from the interior of tubes such as are employed in the construction of steam boilers,
sugar liquor evaporators, condensors, and the like.
That portion of the apparatus which operates upon the material to be removed
from the interior of the tube is made up more or less in a manner similar to the well
known tube brushes and scrapers, but instead of being pushed by hand and being
slightly larger than the internal diameter of the tube, it is slightly smaller and is
caused to revolve by mechanical means, the axis of revolution coinciding with the
centre line or axis of the tube. In order to obtain the requisite pressure of the
brush or scraper it is divided into two or more sections longitudinally which are
hinged near the axis on the longitudinal edges so that when the brush or scraper
is caused to revolve at a suitable speed the centrifugal action generated will cause
the section of the scrubber to press against the interior surface of the tube. The
construction is such as to allow of a certain size of scrubber serving to clean various
sizes of tubes larger than the smallest size for which a particular size of scrubber
is made; the expanding action due to its quick revolution causing the surface of
the brush to fill the tubes up to the limit of its expansion. This action likewise
allows of completely wearing out the whole of the wires or other substance of which
the scrubber is made. Instead of the sections being hinged they may be constructed
of flexible material, or by a method of positive expansion which could be adjusted
before use or allowed to expand by centrifugal action. The head, or brush, or
scraper part of the scrubber is fixed on the end of a shaft slightly longer than the
length of the tube to be cleaned, and this shaft is contained in a hollow tube which
serves as a support for the revolving shaft and also provides the means for the
operator to handle the apparatus and insert it into the tube which is to be cleaned.
A "flexible shaft" of the well-known construction of suitable length and driven
by convenient power is attached to the shaft which is connected to the head of the
scrubber. When set in motion, the operator has only to push the scrubber through
the length of the tube (the revolving of the scrubber materially assists this
operation) and as it may revolve about 500 revolutions per minute, the tube will
be found to be clean however quickly the scrubber may be made to traverse the
length of the tube and be withdrawn.
Other well-known mechanical methods may be employed to communicate motion
to the end of the scrubber shaft, such as an arrangement of positive gearing mounted
on a suitable framework conveniently arranged to be moved into a position exactly
opposite the tube to be operated upon, and the mechanism might be so constructed
as to perform the work automatically.
An electro-motor could also be attached directly to the end of the scrubber
shaft, and the electric current led thereto by wires which would be loose and
flexible.
In order that my invention may be properly understood and readily carried
into effect I have hereunto appended two explanatory sheets of drawings in the
several figures of which corresponding parts are marked with the same letters of
reference.
Figure 1 is a longitudinal section.
Figure 2 is a section taken through the line a b, Figure 1.
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page_text: Figure 4 is also a section showing the end of the revolving shaft to which the
flexible tube is attached.
The brush or scraper is divided into three longitudinal sections A, A', and A²,
each of which is composed of two pieces B, and C, B containing the wires or other
substance of which the scrubber is made, and C being hinged at one of its longi-
tudinal ends to a triangular shaped axle or hub D, as seen more particularly at
Figures 1 and 2. These pieces B and C are held together by screws d or their
equivalent. Screwed into the head of the brush or scrubber is a shaft E a little
longer than the length of the tube to be cleaned, and this shaft is contained in a
hollow tube F provided with bearing blocks G, H, and I, having oil-holes e for
lubricating. This hollow tube F provides the means whereby the operator is
enabled to handle the brush and insert it into the tube to be cleaned. A flexible
shaft J of the well-known construction and driven by any convenient power is
attached to the end of the revolving shaft E which is connected to the head of the
scrubber. Where the flexible shaft J joins the revolving shaft E there is a guard K.
When the brush or scrubber is made to revolve, the centrifugal action generated
will cause the sections A, A', and A2 to expand so that the wires will press against
the interior surface of the tube to be cleaned. When the scrubber is set in motion
the operator only requires to push it through the length of the tube, which operation
is greatly assisted by the revolving of the scrubber, and when it is desired to with-
draw the brush for the purpose of cleaning another tube without stopping the
driving power, a sleeve L having a conical surface is slipped over the conical neck
of the brush.
Figure 5 is a longitudinal section of a modification.
Figures 6 and 7 illustrate the brush in the operation of cleaning the tubes of a
locomotive boiler tube.
Instead of the pieces C being hinged to the axle D as hereinbefore described
with reference to Figures 1 and 2, they may be constructed of flat flexible plates C¹
fixed by screws to one end to the axle D. The axle D is provided with indenta-
tions so as to enable the heads of the screws which connect the pieces B¹ and C¹
together to lie in them when the brush is not rotating. When the brush is in
operation and is becoming expanded, the resistance of the flexible plates C¹ is
overcome by the centrifugal action set up, and the brushes press against the inner
surface of the tube as more particularly seen in Figures 6 and 7. To check any
undue expansion and to prevent the surface of the pieces B₁ rubbing against the
interior of the tube when the wires are worn down a stop is provided as shown
in Figures 5 and 6.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
A revolving scrubber having hinged expanding or flexible brushes actuated by
mechanical electrical or other suitable means for removing incrustation soot, scale
or other deposit from the interior of tubes such as are employed in the construction
of steam boilers, sugar liquor evaporators, condensors, or the like, constructed
substantially as described and shown on the accompanying sheets of drawings.
Dated this 25th day of September 1891.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.