Improvements in Steam Engines.
Year: 1893

page_text: Date of Application, 6th Feb., 1893
Complete Specification Left, 6th Nov., 1893-Accepted, 27th Jan., 1894
PROVIDIONAL
DIEVITICATION.
Improvements in Steam Engines.
I, NOËL CHANDLER, of Cannock Chase Engine Works, Hednesford, in the
County of Stafford, Engineer, do hereby declare the nature of this invention to be
as follows:-
:-
In the Specification of a former Patent granted to me the 18th April 1888
No. 5792 is described a type of compound single-acting closed-in engine having two
piston valves, one for the high pressure and one for the low pressure cylinder and a
sleeve valve adapted to admit of the passage of steam through itself, whilst its
periphery commands the exhaust passage from the low pressure cylinder. In an
engine of this type according to my present invention I combine with the two
pistons and their common rod a distance tube placed upon the rod between the
two pistons, the whole being secured together by a nut or nuts placed upon a screw
threaded portion of the piston rod above the high pressure piston so that no nuts
are required on the low pressure piston to secure it to the piston rod.
In engines of the type referred to according to my former Patent above mentioned,
there was provision only for admitting high pressure or live steam for the purpose
of cushioning, to one of the two cylinders, namely the top cylinder. Now according
to my present invention such an engine is so constructed that steam can be admitted
either to the upper cylinder, or to the lower cylinder, and on top of either, or both,
of the pistons, just before they reach the highest point or top centre, so that the
engine can be run at a high speed.
For the purpose of admitting steam to the lower cylinder the distance tube
hereinbefore referred to is made of an internal diameter sufficient to enclose an
aunular space around the piston rod, and holes are formed through the said tube
whereby low pressure steam can pass from the under side of the high pressure
piston by the annular space into the low pressure cylinder above its piston.
Above the high pressure cylinder there is a cushion or lead cylinder with steam
port and pipe leading either to the high pressure steam chest or it may be to the
boiler. Within the cushion or lead cylinder there is a valve fixed on the piston
rod with a distance tube interposed between such valve and the high pressure
piston. When the pistons have descended a short distance (depending
on the size
of the engine), steam is cut off so far as the high pressure cylinder is concerned by
the valve last referred to closing the port in the cushion or lead cylinder. Instead
of the distance tube between the valve and the high pressure piston, I may some-
times employ a tube with holes and passages as in my earlier Specification already
referred to. In order that the point of cut off may be varied in the lead cylinder
the lead valve may be so connected and arranged that it can be raised or lowered
when desired, or the port or hole in the same cylinder may be varied in height
which will have a similar effect.
I may sometimes employ the "lead" or cushioning arrangement hereinbefore
described, in engines having two or more cranks, in which case the cylinders will
be arranged, side by side, as in the Specification of Letters Patent granted to me
No. 14.419 of 1890.

page_text: I prefer to employ a closed crank-chamber provided with large removable doors
at the back and front as and for the purpose described in the Specification of
Letters Patent granted to me dated 18th April 1888 No. 5792.
Dated this 6th day of February 1893.
.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Engines. .
1, NOËL CHANDLER, of Cannock Chase Engine Works, Hednesford, in the
County of Stafford, 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 :-
In the Specification of a former Patent granted to me the 18th April 1888
No. 5792 there is described inter alia, a type of compound single-acting closed-in
engine having two piston valves, one for the high pressure and one for the low
pressure cylinder and a sleeve valve adapted to admit of the passage of steam
through itself, whilst its periphery commands the exhaust passage from the low
pressure cylinder.
Now according to my present invention in order that such an engine may be
safely run at a high speed and in a silent, or practically silent, manner, it is so
constructed that steam can be admitted either to the upper cylinder, or to the lower
cylinder, or to both cylinders, and on top of either, or both, of the pistons therein,
just before they reach the highest point or top centre, as I will now proceed to
explain by aid of the accompanying drawings in which,
Fig. 1 shows partly in vertical section and partly in elevation, sc much of a
compound single acting engine as is necessary to illustrate the application thereto
of my present improvements. 1 and 2 are the high and low pressure cylinders
arranged one above the other and fitted with pistons 3 and 4 respectively; and
5 and 6 are the high pressure and lower pressure steam valves for controlling the
passage of motive fluid to and from the said cylinders through the passages or
ports 7 and 8 respectively, as described in my said former Specification. The
pistons 3 and 4 are mounted upon a common rod 9, the piston 4 resting against a
shoulder 9 on the rod and the piston 3 freely fitting the said rod, and between the
pistons 4 and 3 and above the latter one, and surrounding the rod, are distance
tubes 10 and 10%, the arrangement being such that by screwing a nut 11 ou the rod
above the upper tube 10%, both pistons will be firmly secured on the rod by one
tightening operation, thereby dispensing with the separate nuts or fastening devices
heretofore usually employed for fixing the low pressure piston on the rod, and
facilitating the construction and repair of the engine. I do not however make any
claim to this mode of securing the pistons to the piston rod.
For the purpose of admitting steam to the upper end of the cylinder 2 and above
the piston 4 therein for the purpose of cushioning the piston when the same is
completing its upstroke, the distance tube 10 is made of such an internal diameter
as to enclose an annular space 12 around the piston rod at the part shown, and
holes 12° 12° are formed through the said tube whereby low pressure steam can pass
from the under side of the high pressure piston 3 by the space 12 into the low pressure
cylinder 2 above its piston 4, when this piston is nearing the end of its upstroke
and is in such a position that the set of holes 12" are within the high pressure
cylinder whilst the other set are within the low pressure cylinder. The perforated
tube 10 thus forms a valve which moves with the pistons. The passage. 12 and
holes 12ª 12b constitute what I call a "lead" passage.

page_text: For the purpose of admitting high pressure or live steam to the high pressure
cylinder for cushioning the piston
cylinder a cushion or lead cylinder 13 having a steam port 14 which, by. means of
in that cylinder, there is arranged above the said
the branch 15 is placed in communication either with the high pressure steam
chest 16, or it may be with the boiler direct. Within this cylinder 13 is a valve 17
fixed by means of the nut 11 on the piston rod 9 which is made of suitable length for
this purpose, the distance tube 10ª being interposed between such valve and the high
pressure piston 3. As will be seen the arrangement is such that when the high.:
pressure piston 3 uears the upper end of its stroke, the valve 17 will uncover the.
steam port 14 and allow high pressure steam to pass downward through the annular
lead passage 18 so as to act upon and cushion the piston 3.
When the two pistons 3-4 have descended a certain distance, depending on the
size of the engine, the said valve 17 will close the said port 14 and cut off the supply
of such high pressure or cushioning steam to the high pressure cylinder through
the lead passage 18, and the lead passages 12 12 12, will have passed out of.
communication with the cylinder 1 and cut off the supply of cushioning steam to.
the low pressure cylinder, but the main valves 5 and 6 will admit steam to the two
cylinders through the passages 7 and 8 respectively after the supply of steam to
the lead passages has been cut off.
As will be obvious the construction of the lead passages may be variously modified
without departing from the essential features of my invention.
Fig. 2 is a similar view to Fig. 1; and
Fig. 3 is a cross section on the line X X of Fig. 2, illustrating a modified'
construction in which the tube 10 has formed in its exterior a number of vertical
grooves 12 that serve as lead passages, these grooves being of such a length and
formed at such a part of the tube 10, that steam can pass through them from the
lower end of the high pressure cylinder to the upper end of the low pressure
cylinder just before the low pressure piston completes its upward stroke. In other
respects the arrangement is similar to that shown in Fig. I and is similarly
figured.
Fig. 4 is a similar view to Fig. 1 illustrating another modified arrangement in
which the lead passages for both the low and the high pressure cylinders are in
the form of longitudinal vertical grooves 12 and 18* formed in the exteriors of the
distance tubes 10 and 10 respectively. 19 and 20 are metallic packing rings for
the tubes 10 and 10ª respectively.
Fig. 5 illustrates a further modified arrangement in which the lead passages 18*
for the high pressure cylinder are formed within the distance tube 10ª and terminate
in ports 18, 18 that are in communication with the lead cylinder 13 and the upper
end of the high pressure cylinder 1 respectively when the piston nears the end of
its upward stroke. The lead passages 12* for the low pressure cylinder in this
example are similar to those shown in Figs. 2 and 3.
In the further modified construction shown in Fig. 6, the high pressure piston 3.
is shown as a-trunk piston, and--the lead-passages 11, 11, 11b for placing the
cylinders 1 and 2 in communication with each other at the required times are formed
within the lower end or extension 3" of such piston, these lead passages, and also
those 18*, 18, 18 for admitting steam to the top of the high pressure cylinder
being constructed in a similar manner to those shown in Fig. 5 for admitting high
pressure steam to the high pressure cylinder.
My invention can be applied to single acting compound engines of various
kinds.
Thus I may sometimes employ lead or cushioning arrangements such as herein-
before described in engines having two or more cranks, in which case the high and
ow pressure cylinders will be arranged side by side as in the Specification of
British Letters Patent. granted to me No. 14,419 of 1890, the cushioning
rrangement being applied to the top of each cylinder.
In all cases I prefer to employ a closed crank chamber constructed with large
penings both back and front, each closed by a removable door or cover whereby

page_text: easy access can be obtained when desired to the stuffing boxes and other parts
within the crank chamber as described in the Specification of Letters Patent
granted to me, dated 18th April 1888 No. 5792.
By constructing single-acting compound engines, with lead passages as described
so that steam will be admitted to the upper ends of the high and low pressure
cylinders so as to cushion the pistons therein at the required times, independently
of the main valves 5 and 6, I am able to arrange these main valves with little or
no lead with the result that I can cause them to give an earlier and therefore more
economical cut off of the steam and at the same time enable the engine to run
As will be obvious
safely at a high speed, and in a silent or nearly silent manner.
the high pressure cylinder.only, or the low pressure cylinder only may be provided
with a lead passage or passages such as described, but I consider it more
advantageous to provide such passage or passages for each cylinder.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. A single-acting compound engine the piston rod of which is constructed with
one or more "lead" passages whereby steam can pass from the underside of the
high pressure cylinder to the upper side of the low pressure cylinder just before
the low pressure piston completes its upward stroke, substantially as herein
described for the purpose specified.
2. A single-acting compound engine in which the high pressure cylinder is
provided at its upper end with a cushion or lead cylinder formed with a lateral
steam inlet controlled by a slide valve carried by an upward extension of the
piston rod, this valve being so arranged and operated as to open the steam inlet
and permit high pressure steam to pass to the top of the high pressure piston and
cushion the same as it nears the upper end of its stroke, substantially as herein
described.
3. A single-acting compound engine constructed with lead passages for admitting
steam to the high pressure cylinder and also to the low pressure cylinder
independently of the main valves substantially as hereinbefore described for the
purposes specified.
4. My improvements in single acting compound engines substantially as herein-
or modified as
before described with reference respectively to and shown in Fig.
shown in Figs. 2 and 3; in Fig. 4; in Fig. 5; and in Fig. 6 of the drawings
annexed for the purposes specified.
.
2000
NOËL CHANDLER.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.