IMPROVEMENTS IN SCRAPERS FOR CLEANING THE OUTSIDES OF THE TUBES OF FUEL ECONOMISERS OR STEAM BOILERS
Year: 1880

page_text: LETTERS PATENT to George Preston, of Manchester, in the County of
Lancaster, Engineer, for an Invention of "IMPROVEMENTS IN SCRAPERS FOR
CLEANING THE OUTSIDES OF THE TUBES OF FUEL ECONOMISERS OR STEAM
BOILERS."
PROVISIONAL SPECIFICATION left by the said George Preston at the Office
of the Commissioners of Palents on the 22nd March 1880.
GEORGE PRESTON, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN SCRAPERS FOR CLEANING THE OUTSIDES OF THE TUBES OF
FUEL ECONOMISERS OR STEAM BOILERS."
My Invention consists in forming the scraping edges of the scrapers at an angle
so that when fitted together they form spirals round the tube to be cleaned. I use
four or other convenient number of scrapers overlapping each other at the ends so
as to clean the entire surface of the tube. Each scraper is made in duplicate,
having a cutting or scraping edge above and below, the duplicate parts being
connected together by a curved or spiral connecting piece, so that the upper and
lower scraping edges act on opposite sides of the tube. On the connecting piece
nearer the upper scraping edge I cast or form a projection which rests upon the
lifting bar, thus causing both the scraping edges to press against the tube.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Preston in the Great Seal Patent Office on the 21st
September 1880.
GEORGE PRESTON, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN SCRAPERS FOR CLEANING THE OUTSIDES OF THE TUBES OF
FUEL ECONOMISERS OR STEAM BOILERS."
My Invention consists in forming the scraping edges of the scrapers at an angle
-so that when fitted together they form spirals round the tube to be cleaned. I use
four or other convenient-number of scrapers overlapping each other at the ends s0
as to clean the entire surface of the tube. Each scraper is made in duplicate,
having a cutting or scraping edge above and below, the duplicato parts being
connected together by a curved or spiral connecting piece, so that the upper and
lower scraping odges act on opposite sides of the tube. On the connecting piece
nearer the the upper scraping edge I cast or form a projection which rests upon tho
lifting bar, thus causing both the scraping edges to press against the tube.
And in order that my Invention may be fully understood and readily carried
into effect I will describo the accompanying Sheet of Drawings, reference being
had to the figures and letters marked thereon.
Figs. 1 and 2 are elevations, and Fig. 3 is a plan of one of iny improved scrapers.
a. is the upper scraping edge, b is the lower scraping edge, and c is a spirally shaped
connecting picco on which is the projection g which rests on the lifting bar. The
edges a and b press against opposite sides of the tube, and as the projection g is
nearer the upper scraping edge the additional weight below the lifting bar causes
both edges to bear against the tube on which the scraper is placed. The scraping
edge being formed at an angle it removes the soot from the tube more readily than
if it wero horizontal.
There
Fig. 4 is an elevation, and Fig. 5 is a plan of a tube on which are three of my
improved scrapers. It will be seen that the scraping edges slightly overlap_cach
other and completely encircle the tubo & above and below the lifting bare c.
is one lifting bar to two rows of tubes, and the bar is raised and lowered in the
usual way. el is a guard extending the whole length of the lifting bar to secure
the scrapers on the lifting bar.
Having stated the nature of iny Invention, and described the manner of
performing the same, I wish it to be understood that I do not limit myself to the
exact shape shewn, nor to the number of scrapers used, and I declare that I claim
the scraper made so as to bear against opposite sides of the tube to be cleaned,
substantially as shewn and described.
In witness whereof, I, the said George Preston, have hereunto set my hand
and seal, this Eighteenth day of September, One thousand eight hundred
and eighty.
GEORGE PRESTON. (L.S.)