improvements in Pumping Engines applicable to rotative or non-rotative engines
Year: 1887

page_text: 1, HENRY DAVEY, of 3 Prince's Street, Westminster, in the County of Middlesex,
Engineer 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:-
.
This invention relates to improvements in Pumping Engines applicable to rotative
or non-rotative engines.
Figure 1 shews my invention applied to a rotative engine, and Fig. 2 illustrates its
application to a non-rotative engine. In Fig. 1, A is the cylinder of a rotative
steam pumping engine secured to the engine frame B; and is the piston rod of
the said cylinder attached to the cross-head D. E is a rocking frame fulcrumed
at F, and of which the arm G is connected to the cross-head D by means of the
connecting rod I; whilst the arm H of the said rocking frame is connected by means
of the rod J to the crank K, upon the shaft of which is keyed the fly wheel L ;
M M are pump rods attached to lift pumps and connected at their upper extremities
to the links N N', fulcrumed at P P ; the said pump rods are also connected to
the rocking frame E by means of the connecting rods R R¹. When the piston of the
engine is at mid-stroke the arin G of the rocking frame E, occupying the position g,
will be at right angles to the centre line of the cylinder, and the variation from this
angle will be the same for the two extreme positions g¹ g²; but the angle which the
rod R makes with the said arm G becomes more and more acute as the said arm
travels from the position to g. By this means the leverages of the piston rod and
pump rod are varied relatively and mutually, and the lifting stroke is made with an
increasing effect on one side of the machine while the idle stroke is being made on
the other side.
As the resistance to the lifting pump is constant, and the force by which it is
operated varies by reason of the above-described varying leverage, a varying force
may be employed for operating the steam piston.
In Fig. 2, the fly wheel is replaced by a second cylinder A', the piston of which is
connected by means of the piston rod C, the cross-head D¹, and the connecting rod [¹

page_text: to the arm H of the rocking frame E, which rocking frame is of a slightly different
form to that shown in Fig. 1.
It is not essential that the pump connecting rods should be attached to the same
pins on the rocking frame as those to which the engine connecting rods are attached,
but they may be connected to the rocking frame at such points as r and p.
The valves of the engine, Fig. 1, may be worked by means of the Corliss valve
gear, or by any other convenient form of valve gear applicable to rotative engines.
The valves of the engine, Fig. 2, may be worked by means of the valve gear
described in my Patent Specification No. 81138, or by any other convenient form of
valve gear applicable to direct-acting engines.
Having now described my invention and the manner in which it may be carried
out, I claim,
1. Connecting the connecting rods of the engine and the connecting rods of the
pumps to a rocking frame substantially as described and illustrated.
2. The general construction and combination of parts substantially as described
and illustrated.
Dotad this 30th day of Santamber 1887