OF DRAWINGS
Year: 1898

page_text: Date of Application (in United Kingdom), 18th Oct., 1898
Complete Specification Left, 18th Oct. 1898-Accepted. 29th Apr., 1899
I, SAMUEL CRAWSIIAW, of Reed Street, Oamaru, in the Province of Otago,
New Zealand, Engineer, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The object of my invention is to construct an apparatus for scraping and re-
moving barnacles, rust, or other accumulations or incrustations from the interior
of water or other metal pipes, the said apparatus to be adjustable to various
sizes of pipes and to be operated either by hand or by hydraulic pressure."
DESCRIPTION OF DRAWINGS.
Fig. 1 is a longitudinal section of pipe, showing my improved scraper in posi-
tion.
Fig. 2 is a transverse section of pipe at a, showing the inner side of the piston
used for propelling the scraper through the pipe.
Figs. 3 and 4 are transverse sections of pipe at b and c respectively, showing
the contact of each pair of scraping blades with the pipe.
Fig. 5 is a transverse section of pipe at d, showing the ribbed guide.
In constructing my improved scraping apparatus I employ a central spindle
with a square body A and a screwed end B. To the square part A of the
spindle are bolted longitudinally four steel springs C, each with a free end ter-
minating in a V-shaped steel scraping blade, which is bent to fit the inside
curve of the pipe D to be operated upon.
The said scraping blades are attached in pairs E E and F Fat opposite sides
of the spindle, one pair E E being attached by longer springs, so that each of
the four blades or scrapers overlaps the two adjoining ones (as shown in Figs. 3
and 4). By this means the entire inner surface of the pipe is scraped at each
stroke.
Each pair of scraping blades is regulated or adjusted to any required diameter
of pipe by means of a nut G, which works on the screwed part B of the spindle
and has a central washer H, which said washer H serves as a fulcrum for the
longitudinal springs C and holds the scraping blades in contact (either rigid or
springing as required) with the pipe.
To the outer end of the central spindle B is screwed a piston K. for propelling

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the scraper through the pipe, the said piston being operated by water or other
pressure. The said piston K has a series of springs or hinges L having hardened
steel tips (preferably rivetted), the said springs or hinges adjusting themselves
to the interior surface of the pipe (whether foul or clean) when the pressure is
applied, and also protecting the piston leather M, which is on the pressure side
of the piston, from erosion on the rough surface of the pipe. The said stee!
tips of the hinges or springs L act as additional scrapers, their power varying
with the pressure on the piston leather M.
As the hinges or springs L project beyond the piston leather M, apertures N
are left between the said hinges L. By this means a certain quantity of the
water or other motive fluid passes through and carries away the debris in front
of the scraper, thus keeping the pipe clear and facilitating the working of the
scraper.
At the inner or leading end of the scraper a ribbed guide P is provided to keep
the spindle A central within the pipe D, the said guide P being secured prefer-
ably by a screw and nut and having a number of ribs varying with the diameter
of the pipe D.
A screwed end R may also be provided for working the scraper by hand with
suitable mechanical appliances when required.
In operating the scraper a piece of pipe is cut out for inserting the apparatus
into the line of pipes, a special temporary connection being provided if hydraulic
power is to be employed for propelling the apparatus. The extreme end of the
line of pipes is also opened to obtain a free discharge for the water, debris, and
scraper.
If the scraper is to be operated by mechanical means, a rope or chain is floated
or threaded through the line of pipes for the purpose of pulling the scraper
through; or when used for short lengths of pipe wrought iron rods may be
screwed to the scraper.
In passing through the pipe the scraper presents a series of blades with four
cutting points which plough through the incrustation on the pipe, and which
cannot catch in an ordinary joint, and will slip around any small service pipe
connection projecting into the main pipe.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what
I claim is:-
:-
1. In a pipe scraper the employment of a central spindle having a series of
(preferably four) longitudinal steel springs fixed at one end to the said spindle,
each of the said springs terminating at its loose end in a V-shaped steel scraping,
blade, substantially as shown and described.
2. In a pipe scraper the combination with the aforesaid steel springs and
scraping blades of adjusting nuts and washers screwing on the central spindle,
substantially as, and for the purposes, shown and described.
3. In a pipe scraper the employment of a self-adjusting propelling piston, con-
structed and operated substantially as shown and described.
4. In a pipe scraper the combination of the spindle A B R, the springs C,
the V-shaped scraping blades E F, the adjusting nuts G with washers H, the
propelling piston K, the self adjusting springs or hinges L, the piston leather M
and apertures N, and the ribbed guide P, all arranged and operated substan-
tially as, and for the purposes, shown and described.
Dated this 17th day of October 1898.
JOHN E. WALSH,
Royal Exchange Chambers, Boar Lane, Leeds,
Patent Agent for the Applicant.