IMPROVEMENTS IN OBTAINING RECIPROCATING MOTION IN STEAM ENGINES, AND FOR COMMUNICATING THE SAME TO ANY ORDINARY PUMPS FOR WHATEVER PURPOSE THEY MAY BE EMPLOYED
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by Alfred Paul at the Office of
the Commissioners of Patents, with his Petition, on the 20th January
1863.
I, ALFRED PAUL, of the Parish of Gwennap, in the County of Cornwall, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
OBTAINING RECIPROCATING MOTION IN STEAM ENGINES, AND FOR COMMUNICATING
THE SAME TO ANY ORDINARY PUMPS FOR WHATEVER PURPOSE THEY MAY BE EMPLOYED,"
to be as follows:-
This Invention relates to a compound slot link to be made of wrought iron,
brass, or any other suitable material; the longer of the two slots of which the
said compound slot link is composed is to be of sufficient length and breadth
to allow the end of a tappet arm [which is fixed on the piston rod of any
vertical, diagonal, or horizontal engine, at any suitable distance from the
piston of the said engine,] to travel within it throughout the whole length of
the stroke of the said engine, without coming in contact with either end of the
aforesaid slot. One side of the aforesaid or greater slot is to be circular, or a
part of a circle whose radius will vary according to the required travel of the
slide valve to which it is to be connected, for the purpose of regulating
the induction and eduction of steam to the cylinder of the engine, to which
both the slide valve and link are to be attached. The opposite side is an obtuse
angle, the apex of which points towards the centre of the inner part of the said
circular side of the slot. The angle contained by the two lines forming the
angular side will be greater or less according to the length of the radius of

page_text: the circular side. The three points of the angular side, that is to say, the apex
and two ends, are to be placed at equal distances from the inner part of the
circular side of the slot, which distance is regulated by the size of the end of
the said tappet arm, which will travel within the said slot reciprocally from
end to end. The second slot contained in the said compound slot link. is
placed or situated at or near right angles to a line drawn through the centre
of that portion of the first-named or larger slot which is situated nearest to
the steam cylinder, and at a suitable distance from the said end of the larger
slot. The length and breadth of the lesser slot will entirely depend upon the
required travel and size of the slide valve it may have to give motion to, which
motion will be communicated by means of a fork end or female cap attached
to the outer end of the slide valve spindle, into which fork end or female cap
that portion of the compound slot link containing the lesser slot will be fitted,
so as to slide freely when the link is moved. A pin passing through the fork
end and lesser slot gives motion to the slide valve when the link is moved, so
as to cause either the top or bottom side of the lesser slot to bear upon the
said pin. The compound slot link will be provided with a suitable pin at the
centre of the larger slot, upon which it will turn as a centre when moved by
the tappit arm. The centre of the said pin will necessarily be situated over or
directly opposite the centre of the piston rod of the engine. It will be neces-
sary in the case of very long-stroke engines to have suitable guides for the ends
of the herein-before described slot link to slide in. The action of the link is
as follows:-Given the engine to be motionless, and the position of the slide
valve to be such as to allow steam to enter one end of the cylinder as soon as
it is admitted into the slide jacket, and given the piston to be near the end of
the cylinder into which the steam is to be admitted, this being the case will
necessitate the compound slot link being in such a position as to allow the end
of the tappet arm on the piston rod (as soon as the engine gets in motion) to
travel through one half the larger slot before it will commence to bear upon
the link; as soon as it passes the centre of the slot, and the engine as a con-
sequence has gone half stroke, the tappet arm will begin to bear upon the
circular part of the slot, and will continue to do so until it reaches the end of
its prescribed stroke, and by so doing has caused the link to turn upon its
centre sufficient to reverse the slide valve, and by so doing has admitted the
steam into the opposite end of the cylinder. The larger slot is relatively the
same at both ends or opposite sides of its centre; it will be evident therefore
that the tappet arm will operate in the same way throughout both the outer
and inner stroke of the piston, effecting thereby a very simple and effective
direct reciprocating motion.

page_text: or
I further communicate the motion thus obtained to any ordinary pump or
pumps, such as are used for the purpose of draining deep mines and wells, by
means of a plunger or ram of any required dimensions attached to the piston
rod of the said steam engine, which plunger or ram works in a suitable
working barrel, and acts upon water' therein contained when the engine is
moved on the downward stroke, (which. water is part of a column that extends
through suitable pipes from where the engine may be fixed to the pump
pumps in the aforesaid mine or well at any required depth from the surface.)
At the bottom and connected to this column of pipes is another working barrel
to correspond with the one at that end of the said column which is nearest
the steam engine, into which working barrel is placed another plunger to cor-
respond with the one in the piston rod, at the lower end of which, by means of
a suitable cross head, are attached two other plungers, one of which is to act as
an ordinary force pump to force water from where the pump: may be fixed;
say, in illustration, at a vertical depth of 300 feet from the surface of the mine
or well. The other plunger attached to the said cross head is called an
opposing plunger, because it continually acts in opposition to the engine;'
this plunger is placed in a suitable working barrel attached to but not inter-
nally communicating with the force pump: The working barrel of the
opposing plunger is connected to the rising main or force pump eduction pipe
by means of a suitable pipe, through which the water in the 'rising main will
have free access into the said working barrel; the connecting pipe therefore
allows the water in the rising main to act with the full force of its weight
(about one hundred and thirty pounds per square inch of surface in the present
case) upon or against the bottom of the opposing plunger, with a tendency to'
force it and all thereto attached in an upward. direction. The opposing
plunger is to present sufficient transverse sectional capacity or area to the
weight of water in the rising main to raise (when the engine is on the
return or upward stroke, and therefore offering no resistance to it) the
opposing plunger and all thereto attached, that is to say, the force pump
plunger or plungers, cross head power, transmitting plunger already described,
as well as the column of water within the power transmitting column of pipes,
which is of necessity much smaller than that in the rising main. The water in
the rising main by this Invention is employed as a motive power to raise the
pump plunger, so as to create a suction, for the purpose of supplying the pump
with water from the tanks or wells, from whence the said pump may be em-
ployed to raise it, and that the said pump plunger may have sufficient moment,
and the opposing plunger will have as much additional sectional area over and
above that which is necessary to overcome its inertia (as may be required in

page_text: any particular case for the said purpose). The action of the said apparatus is
as follows: Given the engines and pump tube at the extremity of the upward
stroke when the steam is applied to the engine, its power is transmitted
through the smaller column of water upon the principle of bydraulics to the
pumps in the mine, with a tendency to force the plungers of such pumps
downwards, by which means the charge of water previously contained in the
pums is discharged into the rising main. When by this means the engine
effects this, the discharge clack of the pump closes, thereby cutting off the
connection between the rising main and pump plungers until the engine had
withdrawn its resistance by returning to the extremity of the up stroke and
the opposing plunger has again raised the pump plunger and a fresh charge of
water, when the engine may again repeat its operation.
There are four obvious advantages gained by the using this Invention; they
are as follows:-
First, the obtaining reciprocating motion in steam engines of whatever size,
when rotary motion is not necessary, without the aid of crank, fly wheel,. or
eccentrics, as are usually employed for this purpose.
Secondly, the capability of obtaining a much greater length of stroke that
can practically be obtained by means of beams and cranks.
Thirdly, the comparatively inexpensive and direct way in which the motion
thus obtained is transmitted to the pumps; there being no connecting rods or
balance weights employed obviates the possibility of derangement in such parts,
and effects a great saving in first cost.
Fourthly, the universal adaption of the herein-before described reciprocating
motion to all direct acting, such as fire or any other short-stroke quick
travelling engines (only in such cases be it observed the plunger or ram
attached to the piston rod will be the only plunger employed to work the
required pump, whether force, suction, single, double action pump.