Improvements in the Means or Apparatus for Governing Impulse Turbines.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Means or Apparatus for Governing Impulse
Turbines.
I, SAMUEL CLELAND DAVIDSON of Sirocco Engineering Works, Belfast, Ireland,
Merchant, do hereby declare the nature of this invention to be as follows:-
My improvements refer to the governing of impulse turbines in which more than
one jet nozzle is employed for directing the motive fluid into the buckets thereof.
The objects of my improvements are to maintain the initial pressure and force
of the motive fluid employed for driving the turbine, in full operation through such
of the jet nozzles as are in active work, and to regulate the volume of motive fluid
operating on the turbine, by cutting it off from or admitting it to the jet nozzles one
by one, so as to drive the turbine at approximately any required speed, under varying
loads.
My improvements consist in the employment in or upon the side casing of the
turbine wheel of an annular pipe or tube (hereinafter called the annular supply pipe)
for the main supply of the motive fluid to the jet nozzles which direct the motive
fluid into the buckets of the turbine, and which nozzles are connected thereto on
the side next the turbine, and suitably curved therefrom to give the motive fluid
its required direction, and I preferably construct the said annular supply pipe as
an outwardly open trough in the turbine casing, and enclose its open side by a
steam tight or water tight cover which may be fitted with plugs arranged opposite
each jet nozzle, so that if any obstruction should get into any of the nozzles, it is
only necessary to undo. the plug opposite said nozzle and after pushing a wire
through the nozzle, replace the plug without the cover, as a whole, having to be
removed for this purpose. The inlet ends of the nozzles from the said trough are
each formed in the centre of a slightly elevated surface in the bottom of said trough
all of which surfaces are turned or milled to an uniformly level facing, upon which
I apply a flat ring or annulus which acts as a valve (hereinafter called the valve
annulus) with a number of elevated surfaces each of suitable length and space from
each other, or with holes or slits in it so arranged in respect of the inlet orifice to
each nozzle that when said valve annulus is in a certain position all the jet nozzles
are in communication with the annular supply pipe and by the movement of the
valve annulus to or fro, as the case may be, one jet nozzle after another gets cut off
from or re-opened to the motive fluid supply. By this arrangement the motive fluid
operates on the turbines through each nozzle with the full force due to its initial
pressure up to the time of its being cut off therefrom by the valve annulus. I
preferably arrange the cutting off or reopening of the nozzles so that those opposite
to or half way round from the last nozzle acted on by the valve annulus, are
successively cut off or reopened as the case may be; and I operate this valve annulus
preferably by means of a rack and pinion movement acting on its side, and which
inay either be operated by hand or by a governor driven in any convenient way, either
directly by the turbine shaft or by the shaft driven therefrom.

page_text: It will be obvious that this method of governing the supply of motive fluid to the
various jets, ensures the initial pressure of the motive fluid remaining in full
operation through each jet nozzle until it is itself cut off therefrom by the valve
annulus, and consequently whether the turbine is running with full or partial supply
of motive fluid to suit varying loads the jets act with undiminished efficiency so long
as they are in actual operation..
Improvements in the Means or Apparatus for Governing Impulse
Turbines.
I, SAMUEL CLELAND DAVIDSON of Sirocco Engineering Works, Belfast, Ireland,
Merchant, 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 :-
My improvements refer to the governing of impulse turbines in which more than
one jet nozzle is employed for directing the motive fluid into the buckets thereof, and
more especially to the turbines described in the two other applications for Letters
Patent lodged by me of equal date herewith Nos. 15502 and 15503 of 1896.
The objects of my improvements are to maintain the initial pressure and force of
the motive fluid employed for driving the turbine, in full operation through such of
the jet nozzles as are in active work, and to regulate the volume of motive fluid
operating on the turbine, by cutting it off from or admitting it to the jet nozzles one
by one, so as to drive the turbine at approximately any required speed, under varying
loads.
My improvements consist in the employment in or upon the side casing of the
turbine wheel, of an annular pipe or tube (hereinafter called the annular supply pipe)
for the main supply of the motive fluid to the jet nozzles which direct the motive
fluid into the buckets of the turbine and which nozzles are connected thereto on
the side next the turbine and suitably curved therefrom to give the motive fluid its
required direction, and I preferably construct the said annular supply pipe as an
outwardly open trough in the turbine casing, and enclose its open side by a steam
tight or water tight cover which may be fitted with plugs arranged opposite each jet
nozzle, so that if any obstruction should-get into any of the nozzles, it is only
necessary to undo the plug opposite the nozzle, and after pushing a wire through the
nozzle, replace the plug, without the cover, as a whole, having to be removed for
this purpose, The inlet ends of the nozzles from the said trough are each formed
in the centre of a slightly elevated surface in the bottom of said trough, all of
which surfaces are turned or milled to a uniformly level facing, upon which I apply
a flat ring or annulus which acts as a valve (hereinafter called the valve annulus) with
a number of elevated surfaces each of suitable length and space from each other, or
with holes or slits in it, so arranged in respect of the inlet orifice to each nozzle that
when said valve annulus is in a certain position all the jet nozzles are in
communication with the annular supply pipe, and by the movement of the valve
annulus to or fro, as the case may be, one jet nozzle after another gets cut off from
or reopened to the motive fluid supply. By this arrangement the motive fluid
operates on the turbine through each nozzle with the full force due to its initial
pressure up to the time of its being cut off therefrom by the valve annulus. I
preferably arrange the cutting off or reopening of the nozzles so that those opposite

page_text: to or half-way round from the last nozzle acted upon by the valve annulus, are
successively cut off or reopened as the case may be; and I operate this valve annulus
preferably by means of a rack and pinion movement acting on its side, and which
may either be operated by hand or by a governor driven in any convenient way,
either directly by the turbine shaft or by the shaft driven therefrom.
It will be obvious that this method of governing the supply of motive fluid to the
various jets ensures the initial pressure of the motive fluid remaining in full
operation through each jet nozzle until it is itself cut off therefrom by the valve
annulus, and consequently whether the turbine is running with full or partial supply
of motive fluid, to suit varying loads, the jets act with undiminished efficiency so
long as they are in actual operation.
The accompanying drawings illustrate my invention applied by way of example to
two impulse turbines forming respectively the subjects of two other applications for
letters Patent of even date herewith one of which turbines is in the Specification
termed the Intro-impulse Turbine and the other in the Specification the
Extra-impulse Turbine.
In the accompanying drawings:-
Figure 1 is a front elevation of my hereinbefore referred to Intro-impulse Turbines,
in which according to my present invention the flow of the motive fluid into the
nozzles is controlled and regulated by my herein described annular valve operating
inside an annular duct or pipe to which the jet nozzles are attached, and the
movement of which annular valve is actuated by a centrifugal governor mounted on
and driven by said Intro-itapulse Turbine.
Figure 2 is a side elevation of the turbine,
Figure 3 is a plan.
Figure 4 is a cross section through line a-b of Figure 1.
Figure 5 is a sectional elevation through line c-d of Figure 4.
Figure 6 is a sectional elevation through line e-f of Figure 4.
Figure 7 is a cross section of my hereinbefore referred to extra impulse turbine, in
which according to my present invention, the flow of the motive fluid into the
nozzles is controlled and regulated by my herein described annular valve operating
inside an annular duct or pipe to which the jet nozzles are attached, and the
movement of which annular valve is actuated by a centrifugal governor mounted on
and driven by said extra impulse turbine.
Figure 8 is a section through line -m of Figure 7.
Figures 9 and 10 are a sectional elevation and a cross section respectively of a
valve annulus in which the edges of elevated surfaces are employed to cut off or
admit the supply of motive fluid to the jet nozzles, Figure 9 being a section
taken through line ab of Figure 10 and Figure 10 a cross section taken through
line e-d of Figure 9.
Figures 11 and 12 are an elevation and cross section respectively of a valve annulus
in which the edges of holes or ports in the valve annulus are employed to cut off or
admit the supply of motive fluid to the jet nozzles, Fig. 12 being a cross section
taken through line e-f of Figure 11.
Referring first to Figures 1 to 8 A is the turbine wheel enclosed in the casing B
with a discharge outlet C; and DD are jet nozzles attached to the inner side of
one face of the casing B with their inlet ends and opening immediately over and
communicating with the orifices of ports E. F is the annular duct from which the
ports E lead; this duct F communicates with the motive fluid supply pipe G by the
branch duct F. I is the flat ring or valve annulus and H H are the elevated
surfaces and H H₁ the cutting off edges of the said flat ring or valve annulus. These
elevated surfaces rest upon the bottom surface of the duct F and are kept in position
by having springs J attached to the back surface of the valve annulus l'and bearing
against the inner side of the cover K. On part of the outer circumference of the
annulus valve or ring I, teeth I, are formed which gear with a pinion M mounted on
spindle N passing through the cover K and carried by the bracket bearing O. On
the outer end of the spindle N another toothed pinion P is fixed, gearing into a

page_text: rack Q, supported in guides attached to the standard of the centrifugal governor R,
the rack being operated by the raising or lowering of the sleeve S of the
governor R. T is the turbine shaft on which the turbine wheel A is fixed and
mounted, and on one end of which a small pinion U is attached, gearing into the
spur wheel V fixed and mounted on the second shaft W upon which shaft a driving
pulley X is fixed, and also the small pulley Y from which the governor pulley Z is
driven by means of a belt, or sprocket wheels and chain may be suitably used for this
purpose, such as are fitted to bicycles.
The action is as follows:-The motive fluid first enters the turbine by the pipe G
and passes through the branch ducts F to the annular duct Fand from there through
the openings or ports E to the nozzles D from which it issues in the form of jets
which play into the buckets of the turbine wheel A and causes it to revolve, the
motion being transmitted to the pulley Y through the shaft T, pinion U, spnr wheel V
and the second shaft W. A belt connecting the pulley Y with the pulley Z of the
governor R transmits the motion thereto, the governing balls flying further out or
falling inwards as the speed of the turbine is increased or diminished, which raises
or lowers the sleeve S and correspondingly operates the rack Q and pinion P,
transmitting the rotary to and fro movement as the case may be of the pinion I'
through spindle N and pinion M to the valve annulus I, which movement brings one
valve face after another over or off the inlet orifices to the nozzles, whereby the supply
of motive fluid is shut off or opened to the nozzles one by one, and its volume thereby
regulated so as to maintain in the turbine an approximately equal speed of rotation
under varying loads, provided the maximum load is not in excess of the power for
which the turbine is designed.
In Figures 9 and 10, I is the valve annulus; H H are the elevated surfaces of
varying lengths with cutting off edges H. The inlet orifices to the nozzles are shown
in dotted lines and indicated by numbers 1 to 20, the figures being in the order in
which the supply of motive fluid to said orifices would be cut off one after another
by the edges H¹ of the valve annulus I when rotated in the direction of the arrow.
In Figures 11 and 12, HH are the holes or ports of varying length with cutting off
edges H¹..
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. In impulse turbines in which the motive fluid driving the same is directed into
the buckets from a plurality of jet nozzles, the combination with sail nozzles of an
annular motive fluid supply pipe in parallel plane with that of the turbine wheel,
orifices at the side of said supply pipe with which the inlet ends of the respective
jet nozzles are connected, an apertureless annular slide valve inside of said supply
pipe movable on the inner face of said pipe next the turbine wheel and closing said
orifices one by one, and means-for imparting movement to said slide valve, substanially
as and for the purpose set forth.
2. In impulse turbines in which the motive fluid driving the same is directed
into the buckets from a plurality of jet nozzles, the combination with said nozzles of
an annular motive fluid supply pipe in same plane as that of the turbine wheel, orifices
at the side of said pipe next the wheel with which orifices the inlet ends of the
respective jet nozzles are connected, an annular slide valve movable on the face of
said pipe in same plane and parallel with the turbine wheel and having elevated
valve faced surfaces closing said orifices one by one, and means for imparting
movement to said slide valve, substantially as and for the purpose set forth.
3. In impulse turbines in which the motive fluid driving the same is directed into
the buckets from a plurality of jet nozzles the combination with said jet nozzles of an
annular motive fluid supply pipe, orifices at one side of said pipe with which the
inlet ends of the respective jet nozzles are connected, an annular slide valve movable
on the face of said pipe and closing said orifices one by one, a centrifugal governor
actuated by the turbine wheel and means connecting said governor with said valve,

page_text: whereby the movements of the governor are transmitted to said valve and
correspondingly move it on its axis, substantially as and for the purpose set forth.
4. In impulse turbines in which the motive fluid driving the same is directed into
the buckets from a plurality of jet nozzles, the combination with said jet nozzles of an
annular motive fluid supply pipe, orifices at one side of said pipe with which the
inlet ends of the respective jet nozzles are connected, and annular slide valve
movable on the face of said pipe and closing said orifices one by one, teeth on part of
the circumference of said valve, a pinion gearing with said teeth, and means for
imparting rotary motion to said pinion in either direction, substantially as and for the
purpose set forth.
5. In impulse turbines in which the motive fluid driving the same is directed into
the buckets from a plurality of jet nozzles, in combination with said jet nozzles of an
annular motive fluid supply pipe, orifices at one side of said pipe with which the
inlet ends of the respective jet nozzles are connected, an annular slide valve movable
on the face of said pipe and closing said orifices one by one, teeth on part of the
circumference of said valve, a pinion gearing with said teeth, a centrifugal governor
actuated by the turbine wheel, and means connecting said governor with said pinion,
whereby the movements of the governor are transmitted to said pinion and thence to
said valve, substantially as and for the purpose set forth.
6. The combinations of parts substantially as herein before described and represented
in the accompanying drawings constituting improved means or apparatus for
governing impulse turbines.
Dated this th
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.