Improvements in Boiler Flue or Tube Cleaners or Scrapers.
Year: 1898

page_text: Date of Application, 4th Oct., 1898-Accepted, 10th Dec.,
1898
COMPLETE SPECIFICATION.
Improvements in Boiler Flue or Tube Cleaners or Scrapers.
I, NINIAN BELL HAMILTON, of San Antonia, in the County of Bexar, and State
of Texas, United States of America, 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 relates to boiler-flue cleaners, and has for its object to provide a
simple, strong, light and efficient device adapted for double action, or to operate
both in pulling and pushing, the scraping-blades being adapted for expansion,
respectively, according to the direction of the application of power.
Further objects and advantages of this invention will appear in the following
description, and the novel features thereof will be particularly pointed out in the
appended claims.
In the drawing-
Figure 1 is a perspective view of a flue-cleaner constructed in accordance with
my invention, the parts being adapted for pushing the scraper, and showing in
dotted lines the arrangement of the operating or shifting rod when the scraper
is being drawn through a flue.
Figure 2 is a partial longitudinal section.
Figure 3 is a detail view of one of the adjustable spreaders.
Figure 4 is an end view.
Similar numerals of reference indicate corresponding parts in all the figures of
the drawing.
The scraping-blades 1 are arranged in duplicate, a pair of blades being
arranged at each end of the scraper, and being carried by the spring-arms 2
having a normal tendency toward each other, to fold the co-operating blades when
released. In the construction illustrated, the blades, which are of crescent-
shape, and have circular outer edges for contact with the inner surface of a flue,
are spirally disposed, or are arranged at an inclination whereby when folded their.
contiguous extremities overlap and insure a compact arrangement, as shown in
Figure 4. These blades are preferably attached to the extremities of the
supporting-arms 2, whereby when worn, they may be replaced. In addition to
having an inward tendency, the blade-supporting arms are deflected toward each
other to form cam-surfaces at their inner sides for co-operation with spreading
slides 3, which are mounted between the members of each pair of arms.
In the
construction illustrated, these spreaders are provided with side seats 4 to receive
the arms and prevent displacement, but it will be understood that the number of
arms is not necessarily limited to two, as shown in the drawing, and hence the
spreaders are susceptible of variations in construction to suit the number of arms
employed.
The scraper-shaft or rod 5 extends longitudinally between the supporting-arms
of the scraping-blades, and is mounted for reciprocatory movement in a tubular
guide to which the inner or contiguous ends of the supporting-arms are secured.
In the construction illustrated the aligned supporting-arms at the same side of
the scraper are formed of a continuous bar of metal, and at the point of junction

page_text: of the arms the bar is deflected to form a seat 7 of which the convex side is fitted
in a circumferential groove 8 in the exterior surface of said tubular guide, while
said seats in the bars are engaged by a holding-ring 9 to hold the bars in engage-
ment with said grooves in the guides. This forms a compact, and, at the same
time, strong arrangement of parts, and the displacement of the arms is impossible
without cutting the ring.
As above indicated, the scraper embodying my invention is provided at opposite
ends with transversely or laterally expansible scraping-blades, of which the
members are carried respectively by contracting arms; and that mounted to slide
between these arms are spreaders for separating the members of the blades.
These spreaders are carried by the reciprocatory-rod, which operates through the
central guide of the scraper, and the sliding movement of the operating-rod in
either direction is limited by one of the spreaders coming in contact with the
contiguous end of the guide. The guide is elongated in the first place, to stop
the reciprocatory-rod without allowing the excessive reciprocatory movement
thereof, and also to provide an extended bearing for the rod, to prevent the
bending or twisting but the rod is further guided, with relation to the arms of
the scraper, by the engagement of the spreaders with the opposite edges of the
arms, as herein before described.
Obviously there are differences in the diameters of the bores of different boiler
flues, and in order to adapt the scraper for the different diameters of bores, and
also to enable the blades to be spread to a greater or less extent as the operation
proceeds, I preferably construct the operating-rod with right and left threaded
portions 10 and 11 for respective engagement by the spreaders, and it is obvious
that by turning the rod in one direction the spreaders will be separated longi-
tudinally of the rod, while an opposite rotation will cause the movement of said
spreaders toward each other. Thus, by separating the spreaders longitudinally,
a greater throw of the operating-rod is allowed before this movement is checked
by the contact of a spreader with the end of the guide, and hence a greater
expansion of the scraping blades will be attained. On the other hand, when th
spreaders are adjusted toward each other, the movement of the operating-rod is
limited to a shorter stroke, and hence a less extensive expansion of the scraping-
blades will result.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A boiler-flue scraper provided at opposite ends with expansible scraper-
blades, yielding arms for supporting the members of said blades, a central longi-
tudinal guide by which said arms are supported, an operating-rod extending for
reciprocation through said guide, and spreaders adjustably fitted upon the
supporting-rod upon opposite sides of the plane of the guide, for controlling the
relative positions of the yielding arms and adapted for contact with opposite ends
of the guide to limit the reciprocatory movement of the rod, the adjustment of
the spreaders upon the operating-rod being adapted to vary the extent of move-
ment thereof, substantially as specified.
2. A boiler flue-scraper provided at opposite ends with expansible scraping-
blades, supporting-arms respectively carrying the members of said blades and
Provided with cam-faced inner sides, said supporting-arms having a normal
tendency toward each other. a central guide interposed between the arms, an
operating-rod mounted to slide in said guide and provided with opposite screw-
threaded portions, and spreaders respectively fitted upon said opposite screw-
threaded portions of the operating-rod and adapted to co-onerate with the cam-
faces of the supporting-arms, the throw of the operating-rod and the extent of
lateral motion of the members of the scraping-blades being controlled by the
relative positions of the spreaders upon said rod, substantially as specified.
3. A boiler-flue scraper having a tubular guide provided with a circumferential
f

page_text: groove, bars extending longitudinally in opposite directions from said guide and
provided at their centers with off-set portions engaging the circumferential
groove of the guide, a ring engaging and securing said off-set portions of the
bars in the groove of the guide, scraping-blade members carried respectively by
the extremities of said bars, an operating-rod mounted for reciprocatory move-
ment in the guide, and spreaders carried by said rod for expanding the scraping-
blade, substantially as specified.
Dated this 3rd day of October 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.