IMPROVEMENTS IN DIRECT ACTING ENGINES
Year: 1884

page_text: COMPLETE SPECIFICATION.
I HENRY EDWARD NEWTON of the Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of Middlesex, Civil Engineer, do hereby declare the
nature of the invention for IMPROVEMENTS IN DIRECT ACTING ENGINES, and in
what, manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
The present invention relates to that general class of engines which are known
as "direct acting," and particularly to those engines of this class which are
provided with one or more compensating or auxiliary cylinders and pistons, which
are supplied with a suitable motor fluid, and are arranged to act in opposition to
the main piston or pistons during the first part of the stroke of the latter, and in
conjunction therewith during the latter part of the stroke, one form of such an
engine being shown in the Specification of Letters Patent granted to Charles
Campbell Worthington and dated 29th January 1884 N° 2342.
It is the primary object of the present invention to provide this class of engines
with an air compressing apparatus, which will operate to maintain a quantity of
air under sufficient pressure to properly supply the said compensating cylinder or
cylinders. It is also the object of the invention to provide an air compressing
apparatus which will be especially suited for use in connection with direct acting
engines for this and other analogous purposes.
To these ends the invention consists broadly of the combination with the main
and compensating cylinders and pistons, of a tank for containing a quantity of
air to supply said compensating cylinder or cylinders, and an air compressing
apparatus operated by the engine to maintain the proper pressure in said tank.
The invention also einbraces the combination with a direct acting engine of this
class, of an air compressing apparatus driven by the engine, and arranged to make
two strokes to one of the engine, and also various other combinations, all of which
Povics fi/1

page_text: will be hereinafter fully explained, and particularly pointed out in connection with
the accompanying drawings, in which
Fig 1 is a side elevation of a direct acting duplex pumping engine of the
character shown in the specification of the said former Letters Patent, provided
with an air compressing apparatus embodying the present invention.
Fig 2 is a plan view of the same;
:
Fig: 3 is an end elevation, partly in section, of the same, looking from the right
of Figs 1 and 2; and
Fig 4 is an enlarged vertical section taken upon the line x x of Fig: 3.
Referring to said drawings, it is to be understood that the engine therein shown
which, as just stated, is of the same general construction as that shown in the
specification above referred to, consists of two steam cylinders 10, 11, provided with
the usual steam chests, and two water cylinders 12, 13, provided with the usual
suction and force chambers, the pistons of the cylinders 10, 11 being connected
directly to the pistons or plungers of 12 and 13, and provided with the usual
_connections 20, 21, 22, 23 and 24, 25, 26, 27, by which the induction and exhaust
valve of each side of the engine is operated by the other, all in the same manner
as in the well known Worthington Duplex Pumping Engine. Each of the
cylinders 10, 11, is also provided with suitable cut off valves and connections
28, 29, for operating the same, all as fully explained in the said former specification.
As herein shown, the cylinders 10, 11 are arranged to operate in connection with a
tank, not shown, the steam being received from the generator through the pipe 14,
and after acting in the cylinder 10, passing out through the pipe 15 to the tank,
from which it passes through the pipe 16 to the cylinder 11, where it acts at a
reduced pressure, after which it is exhausted through the pipe 17 into a condenser
(not shown), or into the open air, Each of the cylinders 10, 11 may however
receive steam direct from the boiler, and exhaust it directly into the condenser, or
into the open air, said cylinders in such case being of substantially the same size.
The piston rods 18, 19, instead of terminating inside the water cylinders, are
extended, and pass through stuffing boxes in the opposite ends of said cylinders,
where cach of said rods is connected to the piston rods of a pair of oscillating
cylinders 30, 31, which are arranged in any convenient position; and provided with
connections through which they are supplied with a suitable motor fluid. As
herein shown, these cylinders are mounted upon trunnions which are supported in
bearings in a suitable frame work 32 connected to the ends of the water cylinders,
and are supplied through pipes 33, 34, which communicate with ducts in said
trunnions, and with a tank 35, all as fully shown and described in the specification
before mentioned.-Instead of being supported, located, and supplied in the manner
herein shown, these compensating cylinders may be supported in any other convenient
manner, and may be located in any other convenient position, and arranged
to act directly upon the piston rods, or upon any other moving part of the engine,
and they may also be provided with any other suitable connections for receiving
the motor fluid, all as fully explained in the said former specification.-So, also,
instead of being constructed and arranged to operate in the manner herein shown,
these cylinders may be constructed and made to operate in any of the ways shown
in the said specification, or in any other suitable manner.
As explained in the said specification, the motor fluid, which is admitted to the
compensating cylinders 30, 31, may be steam, which can be supplied from the
boiler of the engine, and admitted to the cylinders either directly or through a tank
in which it is maintained at a uniform pressure. It is preferable however, in
many cases, to employ compressed air in the compensating cylinders in place of
steam, and, as before stated, it is the object of the present invention, among other
things, to provide the engine with a suitable apparatus for maintaining a sufficient
volume of air under proper pressure for this purpose.
This apparatus, as herein shown, consists of a single-acting air-compressing
pump 36, located at the side of the water cylinder 13, and constructed and operated

page_text: as follows: The pump 36 is provided at its bottom with one or more induction
ports 9, which are controlled by an inwardly opening valve 8, and communicate
with a pipe 37 leading to the open air, and with a discharge port 7, which is
controlled by an outwardly opening valve 6, and communicates with a pipe 38
leading to the tank 35. The cylinder of the pump is open at its upper end, and is
provided with an ordinary trunk plunger 39, which is connected by a pitman 40
with a lever 41, pivotted at its upper end upon a stud extending from the side of
the water end of the engine, and having its other end connected by a rod 42 with
the head 24 upon the piston-rod 19.
The rod 42 is made of such length that when the piston of the cylinder 11 is at
the middle of its stroke, the lever 41 will be in a vertical position, as shown in
figurę 1, from which it results that the plunger 39 of the pump 30 is caused to
make two complete strokes to each stroke of said piston, thereby compressing and
forcing a charge of air into the tank at each stroke of the engine. By this
construction and arrangement, a very small single-acting pump is made to perform
the entire work, while by forcing small charges of air into the tank at short
intervals, a more uniform pressure is maintained therein than if larger charges
were forced in at longer intervals. By means of the toggle joint formed by the
pitman 40 and the lever 41, the plunger 39 is always caused to terminate its
compressing stroke at the same point, even if the strokes of the engine vary in
length. This is a feature of considerable importance, as by this means the amount
of waste or clearance space in the cylinder 36 is reduced to a minimum.
By.reference to figure 4, it will be observed that the pitman 40 is made in two
parts, which are provided with right and left hand screw threads, and are connected
by a correspondingly threaded sleeve or coupling 43, by which arrangement the
length of the pitman can be varied, so that the plunger 39, when at the limit of
its downward movement, will be at any desired distance from the lower end of the
pump cylinder. It will readily be seen, that by thus varying the position of the
plunger at the limit of its downward movement, the amount of air forced into
the tank at each stroke of the pump can be varied at pleasure, because before .any
air will pass out of the pump, the air confined therein must be reduced to a
pressure greater than that of the air in the tank, consequently, the nearer the
plunger 39 approaches to the bottom of the pump, the greater will be the pressure
in the pump, and the greater will be the amount of air forced out of the pump into
the tank, and vice versa.
The operation of the apparatus just "described is as follows:-When it is desired
to charge the tank 35 prior to the starting of the engine, the rod 42 will be dis-
connected from the head 24, or the lever 41, or the pitman 40 from the lever 41,
and the pump 36 will be operated by the hand or otherwise until the air in the
tank has been raised to the desired pressure, to indicate which, the tank may be
provided with a suitable pressure gauge, after which the parts will be reconnected
and the engine set in motion. The compressed air confined in the tank 35 will
then act upon the pistons of the compensating cylinders 30, 31 in the same manner
as described in the specification of the former letters patent herein before referred
to. At each stroke of the engine, the pump 36 will force a small quantity of air
into the tank 35, to take the place of any air which may leak past the pistons of
the compensating cylinders, and so maintain the desired pressure in the tank, the
length of the pitman 40 being from time to time adjusted, as may be necessary, so
as to cause the proper amount of air for this purpose to be forced into the tank.
If desired or found necessary, the tank may, be provided with a suitable relief
valve to prevent the pressure therein from rising above the proper point.
It will readily be understood that in being compressed, as just described, the air
will, owing to the decrease of its volume, become very much heated, and thus heat
the compressing pump. From this it results that the air, as it enters the pump,
becomes heated, and consequently expanded, by contact with its hot surfaces, 80
that as large a quantity is not drawn into the pump as would be the case if the air

page_text: was cool. It is, therefore, desirable in order to preserve the efficiency of the pump,
to provide means by which it is prevented from becoming thus heated.
To effect this, the cylinder of the pump is provided with an annular space (see
figure 4), which is connected with the water end of the engine, or with some other
suitable source of supply, in such manner that a current of cool water is caused to
constantly circulate through said space, and thus cool the surfaces of the pump and
the air as they become heated by the compression.
Although the air compressing apparatus is herein shown as applied to a duplex-
pumping engine, it will of course be understood that it is equally applicable to
single engines which are used for other purposes than pumping, and also that it is
equally applicable to single engines which are provided with one or more of the
compensating cylinders.
In conclusion, it is to be remarked that the connections for operating the
compressing pump may be greatly varied from those shown, without departing
from or losing the advantages of the invention. In fact, the pump may be operated
from any moving part of the engine; and by any suitable form of connections which
may be found desirable.
The device shown for varying the length of stroke of the compressing pump.
illustrates the operation, but the same result can be accomplished by having the
point of connection of the pitman 40 and the lever 41 move in a slide controlled
by a suitable screw, or in various ways; without departing from the principle of the
invention.
It is also to be remarked that the size of the compressing pump, as shown in the
drawings, is greatly exaggerated, it being so shown for the purpose of more clearly
illustrating its various parts.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination, with a main cylinder and piston, of one or more compensating
cylinders and pistons which are arranged to act in opposition to said main piston
during the first part of its stroke, and in conjunction therewith during the last part
of its stroke, a tank communicating with said compensating cylinder or cylinders,
and an air compressing pump which is operated by the engine and communicates -
with said tank, substantially as described.
2. The combination, with a main cylinder and piston, of one or more com-
pensating cylinders and pistons, which are arranged to act in opposition to said
main piston during the first part of its stroke, and in conjunction therewith during
the last part of its stroke, a tank communicating with said compensating cylinder
or cylinders, and an air compressing pump which communicates with said tank,
and is operated from the engine, so as to make two strokes to each stroke of the
engine, substantially as described.
3. The combination, with the main cylinders and pistons forming the two sides
of a duplex-engine, and provided with means by which each side actuates the valves
of the other, of one or more compensating cylinders and pistons arranged to operate
in connection with each side of said engine, and acting in opposition to said main
pistons during the first part of the stroke, and in conjunction therewith during the
last part of the stroke, a tank communicating with said compensating cylinders, and
an air compressing pump which is operated by the engine and communicates with
said tank, substantially as described.
4. The combination, with the main cylinders and pistons forming the two sides
of a duplex engine, and provided with means by which each side actuates the
valves of the other, of one or more compensating cylinders and pistons arranged to
operate in connection with each side of said engine, and acting in opposition to
said main pistons during the first part of the stroke, and in conjunction therewith
during the last part of the stroke, a tank communicating with said compensating
cylinders, and an air compressing pump which communicates with said tank, and is

page_text: operated from the engine so as to make two strokes to each stroke of the engine
operating it, substantially as described.
5. The combination, with a main cylinder and piston and one or more com-
pensating cylinders and pistons arranged to operate in connection therewith, of
a tank communicating with said compensating cylinder or cylinders, an air
compressing pump which is operated by the engine and communicates with said
tank, and means by which the position of the piston or plunger of said pump can
be varied so as to regulate the amount of air forced into the tank at each stroke,
substantially as described.
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