IMPROVEMENTS IN STRAINERS FOR PUMP SUCTION PIPES AND OTHER PIPES AND APERTURES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by James Quick Dunstan at the
Office of the Commissioners of Patents, with his Petition, on the
18th September 1875.
I, JAMES QUICK DUNSTAN, of Falmouth, in the County of Cornwall,
Engineer, do hereby declare the nature of the said Invention for
" IMPROVEMENTS IN STRAINERS FOR PUMP SUCTION PIPES AND OTHER PIPES
AND APERTURES," to be as follows:-
.
The ordinary strainer, rose, or drain in general use is liable to choking
or fouling, because any floating matter in its immediate vicinity is
drawn towards it, and gets attached to its side, thereby rendering the
pipe, pump, or other apparatus more or less useless, frequently causing
loss of life, time, and money, by failing at the very time when all
depends upon its certain action.
The main object of my Invention is to prevent the choking or fouling
of the strainer, and thereby-to render it certain in its action at all times.
For this purpose I make the strainer proper in the form of a perforated
or open worked box or chamber, by preference cylindrical, and I surround

page_text: it with a guard formed with ample interstices or spaces for the free
admission of the fluid therethrough, and by preference consisting of a
scries of helically formed or arranged wires. This guard is attached to
the strainer proper, or to some other convenient part above or adjoining
it. I leave a sufficient space between the strainer proper and the guard, 5
_and in this space I place a revolving fender formed with ample inter-
stices or spaces for the free admission of the fluid therethrough.
-
The revolving fender is by preference made of a series of helically
formed or arranged wires, which by preference wind in a direction
opposite to that of the helical wires in the stationary guard.
The revolving fender is caused to rotate by being connected to a screw
shaped fan or worm placed in the chamber or space above the rose or
strainer proper, which fan is caused to revolve by the action of the fluid
passing through.
1
I prefer to mount this fan on a boss or sleeve which can turn freely 1
on a round stem or bar passing through the chamber and the strainer or
rose proper. I prefer to make the latter with an unperforated or close
bottom, the fluid only entering all round.
When this Invention is applied to apertures in the skin, side, or wall
of ships and other vessels or structures I make the strainer. plate or 2
rose proper of a flat or concave shape, and I place a corresponding
stationary guard outside it, but so as not to protrude beyond the side or
wall. The revolving fender is also made of a corresponding shape, and
consists by preference of a boss having a series of straight or curved
vancs or arms; this revolving fender is likewise, as before described, 2
_connected to a screw-shaped fan or worm- placed in the chamber above
or beyond the strainer proper, the said fan being caused to revolve. by
the flow of the fluid through the said chamber. I make the area of
the apertures through the strainer rather larger than in the ordinary
strainer.
The action of the revolving fender as regards suction pipes and the
like is to force or screw the particles which are drawn towards it in a
downward direction-and away from the strainer, and the action of the
revolving fender for apertures in ships' sides and the like is to throw the
particles out centrifugally.

page_text: Either of the above named descriptions of strainers may be fixed in
any position or at any angle, and cither to a rigid or flexible pipe, so
long as there be no actual contact between the guard and fender and
the sides or bottom of the vessel, tank, or chamber fitted with this
strainer. For application to a flexible hose I stand the apparatus in a
light tripod or other stand.