IM- PROVEMENTS IN LIFTING AND FORCE PUMPS
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by William McLennan at the Office of
the Commissioners of Patents on the 24th July 1876.
WILLIAM MCLENNAN, of Liverpool, in the County of Lancaster, Engineer. “IM-
PROVEMENTS IN LIFTING AND FORCE PUMPS."
This Invention has reference to a simple construction of pump specially applicable
as a lifting pump suitable for ships, capable also of being adapted for forcing liquids,
or as a fire engine; and the nature and novelty of the Invention consists in making
the working barrel in the form of a hollow cylinder, with the lower part semi-
spherical where the piston reciprocates over the inlet branch, which projects down
therefrom as a pedestal or stem with a strong flange cast on it for securing it to
the deck or other suitable foundation as a basement plate, and to which, or a con-
tinuation of it, the lifting main or pipes are attached, preferably by flange joints.
Above this inlet branch within the chamber an A shaped seating is formed, with
the apex reaching to near the centre of the hollow sphere, over which seating radial
inlet valves are fitted, one opening into each opposite side, dividing the hollow
spheroidal chamber into two drawing and forcing or discharging chambers, with a
duplex hollow segmental piston rocking on the said apex towards and from each
face by an oscillating vertical lever inserted in a socket or other equivalent attached
to the middle of this piston, which has a rolling or antifriction packing ring, pre-
ferably of vulcanised india-rubber, working in a segmental spherical groove formed
in its outer periphery, with projecting edges to retain the rolling packing in posi-
tion, which acts against the inner hollow spherical surface of the pump box, so as
to work fluid tight as pistons on each side of the inlet valve, with a discharge
valve lid on the top of the port or opening passing through each segmental side or
piston, all so that when the lever is oscillated, say to the right side, it draws the
water or liquid into the chamber on the left side through its inlet valve, at the same
time discharging the water out of the chamber on the right side through the outlet
valve in its piston, and vice versa, when the lever is oscillated to the left side the liquid
is drawn into the right-hand chamber while being discharged from the left-hand
chamber, in both cases into the cylindrical space above the rocking piston as a dis-
charge well, which is formed with a spout for discharging the liquid at any desired
height from the ship's deck or pump floor or foundation. This rocking piston
might be formed with journal pieces at the ends or right across the centre to work
into covers or division plates when desired to discharge on both sides, and which
would retain the rocking piston in position, especially when used as a force pump.
Price 2d.1

page_text: This improved form or construction of pump may also be made a duplex forcing
pump by forming or fitting on each close drawing and discharge chamber a dis-
charge branch or chamber with a discharge valve and seat, and the discharge pres-
sure pipes jointed to a branch beyond this valve, so that when the pistons were
made without openings through them or having their valve lids fixed down by
pinching screws or other equivalent the water or liquid would be forced out of each
chamber with the in-stroke of the pistons through the said discharge valves, which
would sustain the pressure within the force pipes while the pistons are making
their outward or lifting stroke. Or otherwise, a close hollow semi-spherical or
other top may be jointed on above the duplex piston, to form two discharge cham-
bers there, instead of the open well, having discharge valves to each chamber lead-
ing to a discharge branch common to both, the piston in this case being worked by
having the ends of its oscillating axes working out through liquid-tight stuffing
boxes in the sides of the hollow spherical pump box by levers or other equivalent
outside, either by hand or by motive power, from a crank, eccentric, or cam fly
wheel shaft; thus in either of these said forcing arrangements or modifications of
this pump it acts as a double-acting force pump as well as a lifting pump, and by
fixing the valves in the positions or making them close or solid, and connecting the
opposite diagonal pump chambers by plain open straight branches on the opposite
ends of the pump box or barrel, this pump would be made to act as two lifting and
two forcing pumps cach stroke or oscillation of the piston, or as four double-acting
pumps. And although it has been described as a spherical chambered or barrelled
pump it will be understood that it may be made of a cylindrical or semi-cylindrical
form with flat or disc ends, preferably with one end' jointed, with end packing to
tighten up the radial edges or ends of the pistons against the inner face of these
ends, and only require a straight rolling packing piece of india-rubber at the
segmental ends of the piston, instead of the ring rolling packing required for the
segmental spheroidal piston, and in this case the rolling packing would be better
to be tapered to a smaller diameter in cross section, or towards the two parts of the
ring where it works near the fulcra of the piston, so that the packing ring would
roll smoothly without twisting on the inner periphery of the pump case and outer
periphery or recessed segmental surface of the piston."
This rolling packing is found to work very well on the plain smooth cast sur-
faces of the chamber and piston, but these may be bored and turned when desired
for the smoother working of the rolling packing. And when these new or improved
pumps are used as a fire engine the discharge branches may be fitted with screwed
or other coupling nose branches for the coupling on of the fire hose or closing caps
when these were not required.