Improvements relating to Direct-acting Engines.
Year: 1897

page_text: PROVISIONAL SPECIFICATION..
Improvements relating to Direct-acting Engines.
WE, EDMUND HOWL, of the Quarries, near Dudley, in the County of Stafford,
Engineer, and WALTER WATKINS ATTWOOD, of Fern Bank, Blakebrook, Kidderminster,
in the County of Worcester, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention consists of improvements relating to direct-acting engines of the
type in which the steam or motor cylinder is divided into two equal parts, by a
central annular projection and which receives a double headed trunk piston, forming
a high pressure area between the trunk and the cylinder on each. side of the annular
division ring and low pressure area on the outer ends of trunk piston.
The object of our invention is to provide simple and effective means to ensure the
proper working of the steam moved valve of such an engine under any required rate
of piston speed.
:
In the application of our invention to a compound direct acting steam pump having
a centrally divided single cylinder such as described, we employ a steam moved valve
of a hollow cylindrical type in a circular steam chest, which is preferably arranged.on
the under side of the cylinder. The required movement of the valve to effect the
opening and closing of the cylinder ports in the valve face is attained by steam taken
alternately from each of the high pressure areas on either side of the central division
plate or projection of the cylinder, suitable passages being arranged to convey the
steam from such areas to the admission ports at either end of the valve chest.
The steam for operating the circular valve is conveyed through the admission ports
formed in the chest and also through right angle passages in each end of the circular
valve itself, which works in conjunction with the admission ports in such a manner
that at the proper time the said steam obtains access to the right angle passages and
thus to the valve ends on which it exerts the pressure necessary to move the valve.
Packing rings are provided on the circular valve in such a position that they
alternately close the admission ports in the chests and effectually prevent the passage
of steam to the ends of the circular valve when not required.
The exhausting of the steam from the ends of the valve chest is effected through
right angle passages formed in the chest communicating with an annular passage
in the circular valve, which annular passage is in communication with the main
exhaust port and arranged in such a manner as to exhaust the steam from the ends
of the chest during half the stroke of the circular valve, the said exhaust being thence
completed through the right angle passages in the circular valve hereinbefore
described.
By thus arranging the valve with end packing rings and right angle passages, we
are enabled to ensure the proper working of the steam moved valve under any
required rate or speed of working.
Tinted this 04th day of December 1807
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for the Applicants.

page_text: Improvements relating to Direct-acting Engines.
We, EDMUND HOWL, of the Quarries, near Dudley, in the County of Stafford,
Engineer, and WALTER WATKINS ATTWOOD, of Fern Bank, Blakebrook, Kidderminster,
in the County of Worcester, 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 consists of improvements relating to direct-acting engines of the
type in which the steam or motor cylinder is divided into two equal parts by a central
annular projection and which receives a double headed trunk piston, forming a high
pressure area between the trunk and the cylinder on each side of the annular division
ring and low pressure areas on the outer ends of the trunk piston.
The object of our invention is to provide simple and effective means to ensure the
proper working of the steam moved or like valve of such an engine under any required
rate of piston speed.
In the application of our invention to a compound direct acting pump to be driven
by steam, or other working fluid, and having a centrally divided single cylinder such
as described, we employ a steam moved valve of a hollow cylindrical type in a circular
steam chest, which is preferably arranged on the under side of the cylinder. The
required movement of the valve to effect the opening and closing of the cylinder ports
in the valve face is attained by steam taken alternately from each of the high pressure
areas on either side of the central division plate or projection of the cylinder, suitable
passages being arranged to convey the steam from such areas to the admission ports
or passages at either end of the valve chest.
The steam for operating the circular valve is conveyed through the admission ports
or passages formed in the chest and also through right-angle passages in each end of
the circular valve itself, which work in conjunction with the admission ports in such
a manner that at the proper time the said steam obtains access to the right angle
passages and thus to the valve ends on which it exerts the pressure necessary to move
the valve.
Packing rings are provided on the circular valve in such a position that they
alternately close the admission ports in the chests and effectually prevent the passage
of steam to the ends of the circular valve when not required.
The exhausting of the steam from the ends of the valve chest is effected through
right angle passages formed in the chest communicating with annular passages or
grooves in the circular valve, the annular passages being in communication with the
inain exhaust ports and arranged in such a manner as to exhaust the steam from the
ends of the chest during half the stroke of the circular valve. the said exhaust being
thence completed through the right angle passages hereinbefore described in
connection with the movement of the valve.
By thus arranging the valve with end packing rings and right angle passages, we
are enabled to ensure its proper movement by the steam or other working fluid under
any required rate or speed of working.
In the accompanying sheet of explanatory drawings to be hereinafter referred to:--
Figure 1 is a longitudinal section of a direct acting steam pump cylinder with a
valve chest beneath the cylinder containing a circular valve operated in accordance
with our invention.
Figure 2 is an end section on the line a Figure 1, showing the starting lever in
full, and Figure 3 an end section on the line c & Figure 1.

page_text: Figure 4 is a longitudinal section to a larger scale showing the steam chest and
valve only.
Figure 5 is a central end section of the chest and valve with the starting lever in
full Figure 6 is an end section on the line e f Figure 4.
Figure 7 is a plan of the chest and valve with half in section.
Figure 8 is an elevation showing, in an inverted position the valve only.
The same reference letters in the different views indicate the same parts.
In the position of the circular valve A shown in the drawings the trunk piston has
just completed its stroke in the direction shown by the arrow at Figure 1. With the
ports as shown the live or high pressure steam enters the valve chest through the
admission inlet B and passes into the central space or chainber formed in the circular
valve A. Through such chamber the steam passes by way of the port C into the
annular space D forming the high pressure area for one end of the cylinder. At the
same time the exhaust from the high pressure area E at the opposite end of
the cylinder passes by way of the port F through the chamber of the valve A to the
low pressure area G, and thus the piston is propelled in the direction shown by the
The exhaust steam from the low pressure area H at the opposite end of
the cylinder passes to atmosphere or to a condenser by way of the ports J and J¹.
arrow.
The movement of the valve A necessary to obtain a reversal of the steam distri-
bution is effected as follows:-On the uncovering of the sinall passage K to the high
pressure area D as the trunk piston moves in the direction shown by the arrow at
Figure 1 the high pressure steam obtains access through the pipe L and the
passage L in the steam chest to the right angle passage a² in the valve A and
thence to the end a³ of the valve. The valve A is then, by the pressure of the steam
from the high pressure area D, forced towards the opposite end of the chest thereby
placing the port F in communication with the central chamber of the valve A to
pernit the high pressure steam to flow to the annular high pressure cylinder space E
The same movement of the valve A places its chamber a in communication with the
port C to permit of the passage of the steam from the high pressure area D to the
low pressure area H, whilst by the communication obtained between the ports M
and M the exhaust steam from the area G can pass to atmosphere or to a
condenser.
A communication pipe L2 between the steam chest and the cylinder is arranged at
the opposite end to the pipe I hereinbefore described, and with corresponding
passages to obtain a reversal in the movement of the valve.
The high pressure or live steam admitted to the ends of the valve chest through
the pipes I and L2 respectively, is exhausted, after performing the work of moving the
circular valve A, through the right angle passages N and N¹ respectively, when such
passages are placed in conjunction with the annular grooves 0 or 01 of the valve.
Thus in the drawings the right angle passage N is shown in communication with the
annular passage or groove 0' to exhaust the steam from the adjacent end of
the valve A.
The valve chest admission ports as L' and L3 arranged in conjunction with the
communication pipes L and L2 respectively, are alternately closed by the packing
rings P and P¹ respectively, to prevent leakage of steam from the cylinder to either
end of the circular valve. At Figure 4 the port I³ is shown closed by the packing
ring P¹.
The cushioning of the valve A at each end of its stroke is effected by means of
passages such as Q Figure 7, which permit live steam from the central chainber of the
valve to pass to the ends.
We make the cylinder from two similar castings as shown having the central
division ring secured by the bolts of their adjacent flanges between which such ring
is disposed.
We sometimes employ our improved means for ensuring the proper working of the
steam moved or like valve with a trunk piston coupled directly to a crank shaft instead
of a pump flange as in a directing acting pump,

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. A direct acting engine having a trunk piston forming high and low pressure
cylinder areas and provided with a single controlling valve of a hollow cylindrical
type operated by steam or other working fluid taken alternately from the high
pressure cylinder areas, substantially as described.
2. In a hollow cylindrical valve as A for a direct acting engine, the arrangement
and combination of end ports or passages as a² and packing rings as P and P¹ with
ports communicating between the internal end chambers of the valve and correspond-
ing ports in its circular valve chest, substantially as and for the purpose described
and as illustrated.
3. In direct acting engines the combination with a controlling valve having grooves
as O and O¹ of a steam chest having corresponding passages as N N', substantially as
and for the purpose described and as illustrated.
4. The arrangement and combination of parts forming the improved compound
direct acting engine, substantially as described and as illustrated.
Dated this 14th day of Santamban 1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents for Applicants.