Year: 1896

page_text: 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 more particularly to the class or type of impulse turbines
in which motion is imparted thereto by water, steam, vapour, air or gases (herein-
after called the motive fluid) as jets from fixed nozzles within the periphery of the
turbine into vanes or buckets therein, and in which class of turbines, as hitherto
ordinarily made, the said motive fluid (usually water) passes from the inner to the
outer edges of the vanes or buckets, and escapes therefrom off the periphery of the
wheel in what is known as radial outward flow. In this form of turbines
the aggregate curvature or deflection that said buckets impart to the motive fluid in
passing through them seldom exceeds 140° when the turbine is held stationary, while if
revolving at working speed its absolute or actual deflection is only about one half the
above, and therefore approximately only about 70° or 80°. In the opinion of experts
however the efficiency of turbines, in respect of the action of the motive fluid on the
vanes, "depends only on the angles of entrance and exit and not on the intermediate
form of the curve assuming the latter to be continuous, and the curvature not too
abrupt" (Bodmer on Hydraulic Motors, page 21);. and further that to obtain the
best possible results from the motive fluid used, a deflection of 180° ought to be
effected in its path through the buckets, even when the turbine is revolving at full
speed, and as in the turbines above referred to and as hitherto ordinarily made, this.
air ount of deflection is not accomplished. As their vanes are usually cast in as an
integral part of the turbine, they are consequently unduly thick for working
advantageously with the very fine jets which have to be used when employing steam.
or extra high pressures of water as motive fluid; and the said vanes have also a very
considerable fan action on the surrounding atmosphere, when the turbine is running
at high speeds, whereby a further loss of efficiency in the power obtained is involved..
The objects, (amongst others) of my hereinafter described improvements in impulse
turbines, are to obviate the above mentioned defects, and for this purpose in my
improved turbines I so construct the buckets that they work with water at extra high:
pressures (such as 1000 lbs. and upwards per square inch) steam, vapour, air or gases,.
in the form of jets from fixed nozzles within their circumferential line around the
periphery of the wheel, and cause a deflection thereof in passing through them of on
or about 180°, even when the turbine is revolving at full working speed. In my
construction of buckets the vanes or diaphragms forming the dividing walls between
the buckets are very thin, so that a maximum number of buckets may be employed
around the periphery of the wheel, consistent with the minimum pitch between the.
vanes being sufficient to avoid any undue friction in the passage of the motive fluid
through the buckets; and further the vanes have almost no fan action on the
surrounding atmosphere, while at the same time they are held so strongly on the wheel.
that they themselves and the turbine as a whole have ample strength to withstand the
enormous centrifugal force developed when the turbine is running at full speed, more
especially when steam is used as the motive fluid.
In constructing my improved turbines I preferably make the central part of the
wheel (hereinafter called the turbine wheel) either as a disc annulus mounted on the

page_text: arms or spokes of the wheel or between a pair of discs diverging towards the centre
and rivetted to a central hub keyed on the turbine shaft, or as a solid dise
similarly mounted on the said shaft or spindle, and with a flange or rim (herein-
after called the annular rim) attached on one or both sides of the periphery of the
said dise annulus or solid dise, so as to form a single or double flange thereon, or
applied thereto so as to project over the periphery of the turbine wheel on both
sides of same, in which fatter case it is attached to the periphery of the turbine
wheel as hereinafter described by means of its contained sheet metal vanes, and in
the said annular rim the buckets are formed by one or more circumferential and
suitably shaped concave grooves formed preferably by turning them in the central
part of the inner face of the annular rim (and hereinafter called the rim grooves)
with thin sheet metal diaphragms or vanes (hereinafter called the bucket vanes)
inserted into slits or cuts (hereinafter called the cross cuts) incised across the inner
face of the annular rim to the bottom of the said rim grooves, and into which
cross cuts the bucket vanes fit firmly; whereby the said rim grooves are divided
into a series of buckets; and I preferably set the bucket vanes at such an angle
with the inner face of the annular rim that when they come opposite to any of the
jets of motive fluid driving the turbine, they are approximately in parallel line
therewith, or only face the same to the extent of a few degrees, and the cross section
of the concave curve in the rim groove is such that the line of junction between it
and the transversely inserted bucket vanes, forms an axially directed semi-circular or
semi-elliptical curvature which constitutes the back of the buckets, and round which
the path of the motive fluid is directed in passing through the buckets. The
diameter of this curvature I preferably make equal to about four to six times the
cross-sectional thickness of the jet of motive fluid at the time of its entry thereto,
in practice, however, commencing with a minimum diameter of at least half an inch
for the smallest sizes of jets used therewith, and the distance apart between the
bucket vanes constitutes the pitch or length of the buckets as measured round the
rim. This length I preferably adjust so that the clear width of entrance for the jets
of motive fluid between the bucket vanes is equal to about one half the cross sectional
diameter of the jets of motive fluid at the time of their entry into the huckets, in
practice, however commencing with a minimam space of at least one-eighth of an
inch between the bucket vanes for the smallest sizes of jets used therewith. I usually
construct my herein described improved impulse turbines with two of the said, rim
grooves so located side by side in the annular rim that when each is turned out to
its proper concave curvature in the inner face thereof, their curves meet or cut into
one another at their inner edges, whereby a sharp wedge-like projection is formed
between them, and which edge is preferably a little helow the exposed edge of the
bucket vanes, when inserted as berein before described across the double groove thus
formed. The jets of motive fluid on being directed upon the said short projecting
edge between the grooves, are split thereby to right and left into the axially directed
curvatures forming the back of the buckets between the vanes in each of the rim
grooves, so that a double acting bucket is formed by this combination of double rim
groove with the bucket vanes, from which the return current of the motive fluid is
discharged inwardly in approximately equal parts from its opposite ends. On the
outer face of said annular rim either a metal ring is shrunk on over same or a coil
or wire is wound tightly round it, in order to bind in the annular rim so that its
divided parts between the inserted vanes on its inner face shall be sufficiently
compressed thereon to hold them rigidly in position, and to impart sufficient strength
to the annular rim and to its contained vanes to enable it as a whole to withstand the
centrifugal bursting force developed by the enormously high velocities at which the
same must necessarily revolve when working with steam or with high pressure
hydraulic jets of about 1000 lbs. and upwards as motive fluid. As the cross cuts for
the inserted vanes are only incised to the bottom of the rim groove, acress the inner
face of the annular rim, the outer face of the annular rim thus forms of itself a solid
ring around the buckets, and when, this is further strengthened by a shrunk on metal
ring, its outer side is turned as a plain flat surface, but when a coil of wire is

page_text: employed in lieu of a metal ring the said outer face is grooved in the centre so that
a flange is formed on each side to laterally hold in the coils of wire when wound
round it; and as the centrifugal force acting on the divided parts of the annular rim
and on the vanes between same tends to force them in an outward direction, the effect
of this is only to tighten both more firmly together when the wheel is revolving at its
highest speed. This form of turbine wheel, with its buckets on the inner face of the
rim is therefore specially suitable for steam driven turbines, in which the revolving
velocity, and centrifugal force thereby developed are so enormously high. A further
advantage of the inward acting buckets for the employment of steam as motive fluid,
is that the specific gravity of steam is less than that of the atmosphere, and
consequently the centrifugal force developed when the turbine is running at
extremely high speeds causes the steam after passing round the curvature of the
bucket to be displaced inwardly therefrom by the greater specific gravity of the
atmosphere so that it freely rebounds inwardly out of the buckets without any
tendency to residual lodgment or carrying round therewith, and to which it
consequently imparts its kinetic energy with almost full theoretical efficiency. When
exira high pressures of water such as 1000 lbs. and upwards per square inch are
employed, this form of turbine also gives great efficiency, owing to the fact that such
jets burst into fine spray, almost like steam, and freely rebound inwardly from the
buckets in a similar manner; and in order to prevent the return current from the
ends of the buckets next the turbine wheel, striking its disc or arms and being thrown
thereby back against the buckets, I apply an annular deflecting duct or guide within
the interior circumference of the jet nozzles with its edge projected sufficiently
beyond the interior ends of the buckets to intercept the return current of the motive
fluid therefrom and guide it towards the side of the casing, so that it is directed to the
exhaust pipe clear of the wheel buckets.
According to an alternative modification in the construction of the buckets in my
improved impulse turbine, instead of turning out the rim groove or grooves forming
the axially directed back curvature of the buckets as a continuous concave groove
around the inner face of the annular rim, whereby the circumferential line of the
same is at an acute angle to the face of the bucket vanes and an obtuse angle to the
back thereof, I form the axially directed back curvature of the buckets substantially
at right angles to the back of each bucket vane by substituting for the said continuous
rim groove a series of similarly sized, equi-distant (and preferably milled out) semi-
circular faced steps round the central part of the interior face of the rim each of
which steps is of a depth equal to about one half diameter of the jet of motive fluid
employed with the same, at the time of its entry into the buckets but in practice,
commencing with a minimum of at least one-eighth of an inch for the smallest jets used
therewith; in front of each step there is a flat plane the line of which is at such an
angle with the rim of the wheel that it is approximately parallel with that of the jets
of motive fluid when opposite the same, so that the said jets may impinge direct into
the concave curvature formed by the semi-circular face of each step, without any
material deflection thereof by said plane, on the face of which a thin sheet metal vane
is closely fitted, by inserting it into cuts incised across the face of the annular rim
from edge to edge, in corresponding line with said planes, and extende.l sufficiently
back past the face of each step for the inserted edge of the vanes to be quite covered
thereby. I preferably form the back concave curvature of each step in pairs, located
sufficiently closely together for their inner curves to meet in a sharp wedge-like
projection whereby double return buckets are formed between each pair of vanes
similar to those hereinbefore referred to. The outer ends of the vanes and the divided
parts of the rim between the vanes are also similarly compressed upon the vanes to
securely bind them together as a whole by a shrunk on metal ring or coil of wire.
According to another modification in my improved turbines, when the annular rim
is so applied to the periphery of the turbine wheel that its edges project on both sides
thereof, I construct the same with only one line of circumferentially turned or
alternatively stepped series of concave grooves in its inner face, which therefore
form single acting buckets, and the inflow of the motive fluid jets thereto

page_text: takes place on one side of the turbine wheel and the exhaust or return at
the opposite side and when the annular rim is constructed and applied in this
way it is attached to the periphery of the turbine wheel by extending the central part
of the bucket vanes inwardly into corresponding cuts in the periphery of the turbine
wheel, and turning down and securing the edges of the vanes thereon so as to prevent
. their lateral motion therein.
In any of the above described modifications in the construction of the buckets, it
will be evident that as there is no exterior exit from the buckets towards the periphery
of the wheel there can be no outward discharge of air therefrom, and consequently
they can have no fan action on the surrounding atmosphere, and as the vanes are
sloped backwards from the direction in which the wheel is running, they act with a
minimum of friction upon the atmosphere through which they pass, when the wheel is
revolving. It will also he obvious that as the path of the motive fluid through the
buckets is deflected round a semi-circular or semi-elliptical curvature it necessarily
returns therefrom in a line practically parallel with and in opposite direction to that
of the initial flow of the jet, and as it takes place in an inward direction tangential to
a circle to which the line of the vanes and of the jet (as these coincide) are also
tangential, the forward movement of the wheel between the time that the motive
fluid enters the bucket and its return flow therefrom, does not alter this tangential
direction of the vanes, consequently the return flow of the motive fluid still takes
place in the direction of the nozzle from which the jet issued, so that a deflection of
about 180° is continuously maintained, even when the turbine is running at full
speed; and as the impulse of the motive fluid is communicated to the buckets of my
herein described improved turbines from within the line.of their inner circumference,
and is also returned back again therefrom in an inward direction opposite to that of
its initial flow, they may consequently be appropriately termed intro-impulse
turbines.
When my improved intro impulse turbines are required to revolve alternatively in
reverse directions, as in the case of their employment for driving locomotives or
steamships, I preferably construct them with an annular rim on both sides of the
turbine wheel, and have the vanes therein set to operate in opposite direction; and I
so arrange the motive fluid jets on each side thereof that the admission of the motive
fluid to one side of the disc would shut it off from the other or cice versa,
consequently to reverse the motion of the turbine it is only necessary to admit the
motive fluid on one or other of its sides as required, and with the same arrangement
of annular rim on each side of the turbine wheel, if the vanes be set in corresponding
planes on both sides, a double power turbine may be formed on the one turbine
wheel.
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents...
Improvements in 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 more particularly to the class or type of impulse turbines
in which motion is imparted thereto by water, steam, vapor, air or gases (herein-
after called the motive fluid) as jets from fixed nozzles within the periphery of the
turbine into vanes or buckets therein, and in which class of turbines as hitherto

page_text: ordinarily male, the said motive fluid (usually water) pas us from the inner to the
outer edges of the vanes or buckets, and escapes therefrom off the periphery of
the whe I in what is known as radial outward How. In this form of turbines the
aggregate curvature or deflection that said buckets impart to the motive fluid in
assing through them seldom exceeds 140°, when the turbine is hell stationary, while
if revolving at working speed its absolute or actual defle stion is only about one half
of the above, and therefore approximately only about 70° of 80°. In the opinion of
experts however, the efficiency of turbines in respect of the action of the motive
fluid on the vanes, "depends only on the angles of entrance and exit and not on
the intermediate form of the curve, assuming the latter to be continuous, and the
curvature not too abrupt" (Bodmer on Hydraulic Motors, page 21); and further
that to obtain the best possible results from the motive flail used, a deflection of
about 180° ought to be effected in its path through the buckets, even when the
turbine is revolving at full speed. In the turbin 's above referre.l to al as hitherto
ordinarily made, this amount of deflection is not accomplished and as their vanes are
usually cast in as an integral part of the turbine they are consequently unduly thick
for working advantageously with the very fine jeta which have to be used whin
employing steam or extra high pressures of water as motive fluid; and the said vanes
have also a very considerable fan action on the surrounding atmosphere, when the
turbine is running at high speeds, whereby a further loss of efficiency in the power
obtained is involved. The objects (amongst others) of my hereinafter described
improvements in impulse turbines, are to obviate the above, mentioned defects, and for
this purpose in my improved turbines I so construct the buckets that they work with
water at extra high pressures (such as 1000 lbs. and upwards per square inch) steam,
vapor, air or gases, in the form of jets from fixed nozzles within their circumferential
line around the periphery of the wheel, and cause a deflection thereof in passing
through them of on or about 180°, even when the turbine is revolving at full working
speed. In my construction of buckets the vanes or diaphragms forming the dividing
walls between the buckets are very thin, so that a maximum number of buckets may
be employed around the periphery of the wheel, consistent with the minimum pitch
between the vanes being sufficient to avoid any undue friction in the passage of the
motive fluid through the buckets; and further the vases have almost no fan action
on the surrounding atmosphere, while at the same time they are held so strongly on
the wheel that they themselves and the turbine as a whole have ample strength to
withstand the enormous centrifugal force developed when the turbine is running at
full speed, more especially when steam is used as the motive fluid.
In constructing my improved turbines I preferably make the central part of the
wheul (hereinafter called the turbine wheel) either as a disc annulus mounted on the
arins or spokes of the wheel or between a pair of dises diverging towards the centre
and rivetted to a central hub keyed on the turbine shaft or as a solid disc similarly
mounted on the said shaft or spindle, and with a flange or rim (hereinafter called
the annular rim) attached to one or both sides of the periphery of the said disc annulus
or solid disc, so as to form a single or double flange thereon, or applied thereto so as
to project over the periphery of the turbine wheel on both sides of same, in which latter
case it is attached to the periphery of the turbine wheel as hereinafter described by
means of its contained sheet metal vanes, and in the said annular rim the buckets are
formed by one or more circumferential and suitably shaped concave grooves formed
preferably by turning them in the central part of the inner face of the annular rim
(and hereinafter called the rim grooves) with thin sheet metal diaphragms or vanes
(hereinafter called the bucket vanes) inserted into slits or cuts (bereinafter called the
cross cuts) incised across the inner face of the annular rim to the bottom of the said
rim grooves, and into which cross cuts the bucket vanes fit firmly whereby the said
rim grooves are divided into a series of buckets; and I preferably set the bucket varies
at such an angle with the inner face of the annular rim that when they come opposite
to any of the jets of motive fluid driving the turbine, they are approximately in parallel
line therewith, or only face the same to the extent of a few degrees, and the cross
section of the concave curve in the riun groove is such that the line of junction between

page_text: it and the transversely inserted bucket vanes, forms an axially directed semi-circular
or semi elliptical curvature which constitutes the back of the buckets, and round
which the path of the motive fluid is directed in passing through the buckets. The
diameter of this curvature I preferably make equal to about four to six times the
cross sectional thickness of the jet of motive fluid at the time of its entry thereto,
in practice, however, commencing with a minimum diameter of at least half an
inch for the smallest sizes of jets used therewith and the distance apart between the
-bucket vanes constitutes the pitch or length of the buckets as measured round the
rim. This length I preferably a ljust so that the clear width of entrance for the jets
of motive fluid between the bucket vanes is equal to about one half the cross
se. tional diameter of the jets of motive fluid at the time of their entry into the buckets,
in practice, however, commencing with a minimum space of at least one-eighth of an
inch between the bucket vanes for the smallest sizes of jets used therewith. I may
also alternatively construct my herein described improved impulse turbines with two
of the said rim grooves so located side by side in the annular rim that when each is
turned out to its proper concave curvature in the inner face thereof, their curves meet
or cut into one another at their inner edges, whereby a sharp wedge-like projection is
formed between them, and which edge is preferably a little below the exposed edge
of the bucket vanes, when inserted as hereinbefore described across the double groove
thins formel. The jets of motive fluid on being directed upon the said short pro-
jecting edge between the grooves, are split thereby to right and left into the axially
directed curvatures forining the back of the buckets between the vanes in each of the
rim grooves, so that a double acting bucket is formed by this combination of double
rim groove with the bucket vanes, from which the return current of the motive
Huid is discharged inwardly from the bucket in approximately equal parts from its
opposite ends. On the outer face of said annular rin either a metal ring is shrunk
-on over same or a coil of wire is wound tightly round it, in order to bind in the
annular rim so that its divided parts between the inserted vanes on its inner face
shall be sufficiently compressed thereon to hold them rigidly in position, and to
impart sufficient strength to the annular rim and to its contained vanes to enable it as
a whole to withstand the centrifugal barsting force developed by the enormously high
velo ities at which the same must necessarily revolve when working with steam or
with high pressure hydraulic jets of about 1000 lbs. and upwards as motive fluid. As
the cross cuts for the inserted vanes are only incised to the bottom of the rim grooves
across the inner face of the annular rim, the outer face of the annular rim thus forms
of itself a solid ring round the buckets, and when this is further strengthened by a
shrunk on metal ring, its outer side is turned as a plain flat surface, but when a coil
of wire is employed in lieu of a metal ring the said onter face is grooved in the centre
so that a flange is formed on each side to laterally hold in the coils of wire when
wound round it; and as the centrifugal force acting on the divided parts of the
annular rim and on the vanes between same tends to force them in an outward
direction, the effect of this is only to tighten both more firmly together when the
wheel is revolving at its highest speed. This form of turbine wheel, with its buckets
on the inner face of the rim, is therefore specially suitabie for steam driven turbines,
in which the revolving velocity, and centrifugal force thereby developed are so
enormously high. A further advantage of the inward acting buckets for the employ-
ment of steam as motive fluid, is that the specific gravity of steam is less than that
of the atmosphere, and consequently the centrifugal force developed when the turbine
is running at extremely high speeds causes the steam after passing round the curvature
of the bucket, to be displaced inwardly therefrom by the greater specific gravity of
the atmosphere, so that it freely rebounds inwardly out of the buckets without any
tendency to residual lodgment or carrying round therewith, and to which it conse-
quently imparts its kinetic energy with almost full theoretical efficiency. When extra
high pressures of water such as 1000 lbs. and upwards per square inch are employed,
this form of turbine also gives great efficiency owing to the fact that such jets
burst into fine spray almost like steam, and freely rebound inwardly from the buckets
in a similar manner; and in order to prevent the return current from the ends of the

page_text: buckets next the turbine wheel, striking its dises or arms and being thrown there y
back against the buckets, I apply an annular deflecting duct or guide within the-
interior circumference of the jet nozzles with its edge projected sufficiently beyond
the interior ends of the buckets to intercept the return current of the motive fluid
therefrom and guide it towards the side of the casing, so that it is directed to the
exhaust pipe clear of the wheel buckets.
According to another alternative modification in the construction of the buckets in
my improved impulse turbines, instead of turning out the rim groove or grooves.
forming the axially directed back curvature of the buckets as a continuous concave
groove around the inner face of the annular rim, whereby the circumferential line of
the same is at an acute angle to the face of the bucket vanes and an obtuse angle to
the back thereof, 1 form the axially directed back curvature of the buckets substantially
at right angles to the back of each bucket vane, by substituting for the said continuous
rim groove a series of similarly sized, equidistant (and preferably milled out) semi-
circular faced steps round the central part of the interior face of the rim, each of
which steps is of a depth equal to about one half diameter of the jet of motive fluid
employed with the same, at the time of its entry into the buckets, but in practice.
commencing with a minimum of at least one-eighth of an inch for the smallest jets.
used therewith; in front of each step there is a flat plane the line of which is at such.
an angle with the rim of the wheel that it is approximately parallel with that of the
jets of motive fluid when opposite the same, so that the said jets may impinge direct
into the concave curvature formed by the semi-circular face of each step, without any
material deflection thereof by said plane, on the face of which a thin sheet metal vane-
is closely fitted by inserting it into cuts incised across the face of the annular rim.
from edge to edge, in corresponding line with said planes and extended sufficiently
back past the face of each step for the inserted edge of the vanes to be quite covere
thereby. I may also alternatívely form the back concave curvature of each stop in
pairs, located sufficiently closely together for their inner curves to meet in a sharp
wedge-like projection whereby double return buckets are formed between each pair of
vanes similar to those hereinbefore referred to. The outer ends of the vanes and the
divided parts of the rim hetween the vanes are also similarly compressed upon the
vanes to securely bind them together as a whole by a shrunk on inetal ring or coil.
of wire.
According to another modification in my improved turbines, when the annular rim
is so applied to the periphery of the turbine wheel that its edges project on both sides.
thereof, I construct the same with only one line of circumferentially turned or alter-
natively stepped series of concave grooves in its inner face, which therefore form.
single acting buckets, and the inflow of the motive fluid jets thereto takes place on one
side of the turbine wheel and the exhaust or return at the opposite side and when the
annular rim is constructed and applied in this way it is attached to the periphery of
the turbine wheel by extending the central part of the bucket vanes inwardly into
corresponding cuts in the periphery of the turbine wheel, and turning down and
securing the edges of the vanes thereon so as to prevent their lateral motion therein..
In any of the above described modifications in the construction of the buckets, it
will be evident that as there is no exterior exit from the buckets towards the periphery
of the wheel there can be no outward discharge of air therefrom, and consequently
they can have no fan action on the surrounding atmosphere, and as the vanes are-
sloped backwards from the direction in which the wheel is running, they act with a
minimum of friction upon the atmosphere through which they pass, when the wheel is
revolving. It will also be obvious that as the path of the motive fluid through the-
buckets is deflected round a semi-circular or semi-elliptical curvature it necessarily
returns therefrom in a line practically parallel with and in opposite direction to that.
of the initial flow of the jet, and as it takes place in an inward direction tangential to
a circle to which the line of the vanes and of the jet (as these coincide) are also-
tangential the forward movement of the wheel between the time that the motive fluid
enters the bucket and its return flow therefrom does not alter this tangential direction
of the vanes consequently the return flow of the motive fluid- still takes place in the

page_text: direction of the nozzle from which the jet issued, so that a deflection of about 180° is
continuously maintained, even when the turbine is running at full speed, and as the
impulse of the motive fluid is communicated to the buckets of my herein deserited
improved tarlines from within the line of their inner circumference, and is also
returned hack again therefrom in an inward direction opposite to that of its initial
flow, they may consequently he appropriately termed Intro Impulse Turbines.
When my improved intro-impulse turbines are required to revolve alternatively in
reverse directions as in the case of their employment for driving locomotives, or
steamships, I preferably construct them with an annular rim on both sides of the
turbine wheel, and have the vanes therein set to operate in opposite direction; an
I so arrange the motive fluid jets that they act in opposite directions on each side
thereof and that the admission of the motive fluid to the buckets on one side of the
disc would shut it off from those on the other, or rice. rersu, consequently to reverse
the motion of the turbine it is only necessary to admit the motive fluid to the buckets
on one or other of its sides at one time as required, and with a similar arrangement of
annular rim on each side of the turbine wheel, if the vanes be set in corresponding
planes on both sides and the jets of motive fluid arranged to act thereon in parallel
or corresponding direction, a double power turbine may be thus formed on the one
turbine wheel.
In the accompanying drawings:-
Figure 1 is a front elevation;
Figure 2 is a sile elevation; and
Figure 3 a plan of a turbine constructed in accordance with one modification of
my invention.
Figure 4 is a cross section taken through line a-b of Figure 1.
Figure 5 is a section through line c-d of Figure 4.
Figure 6 is a section through line e-f of Figure 4.
In the modification shown in Figures 1 to 6 the annular rim is fixed to one side of
the turbine wheel and is formed with two rim grooves.
Figure 7 is a cross section through the annular rim and buckets of a molitication
in which annular rims are fixed to both sides of the turbine wheel, and the vanes
therein are shown to be set to operate the wheel in opposite directions.
Figure 8 is a section through line g-k of Figure 7 showing a portion of the
turbine wheel rim and a few buckets.
Figure 9 is a similar section but through line j-k of Figure 7.
Figure 10 is a cross section through the annular rim of a turbine wheel in which
single buckets are employed and the annular rim is fixed direct to the annulus.
Figure 11 is a cross section through the annular rim and buckets of a modification
in which single acting buckets are shown, the annular rim being held in position by
the vanes themselves which are fixed into firmly fitting slits or cuts on the periphery
of the turbine wheel in corresponding line with those in the annular rim.
Figure 12 is a section through line -m of Figure 11, showing a portion of the
turbine wheel rim and bucket.
Figure 13 is a cross section through the annular rim of a turbine wheel with single
buckets in which the annular rim is held by a shrunk on metal ring, E¹ with its outer
circumference formed as a channel for the reception of binding wire. This type of
wheel may, however, be made with a plain metal ring, and without binding wire.
Figure 14 is a cross section through the annular rim and buckets of another
modification, in which the faces of the curves at the hack of the buckets are at right
angles or nearly so to one face of the vanes.
Figure 15 is a section through line no of Figure 14 showing a portion of the
turbine wheel rim and buckets.
A is the turbine wheel complete which is made up of dished dises B, boss C, and
disc annulus D, to which is fixed the annular rim E, with circumferential grooves F
on its inner face, and divided into spaces or buckets G by the insertion of vanes H set
preferably in approximately parallel line with that of the jets of motive fluid acting on
the buckets. The outer circumference of the annular rim E is shown grooved or

page_text: constructed in the form of a channel to receive and keep in position a
wire I.
The wheel A is mounted on and fixed to the turbine shaft J, which may be carried
in any suitable bearings hat is herein shown as mounted in ball bearings K supported
on the outsides of the turbine casing I, which is preferably made in two parts for
convenience of manufacture, with an exhaust or discharge outlet M and mounted on
the bed plate N. In one side of the turbine casing L, a duct O is constructed and
connected with the motive fluid iniet P by branch ducts Q along which the motive
fluid is conducted to the bent and pointed nozzles R fixed to the outer side of the
duct O which faces the turbine through small openings or orifices S, the nozzles R
having a corresponding hole or passage right through them, with suitably proportioned
orifices at their points.
On one end of the turbine shaft J is fixed a pinion T which gears into a spur
wheel U mounted on a shaft V to which is fixed the driving pulley 'W and the
governor pulley X and which shaft V is carried in bearings Y supported by the
casing L.
Z is an ordinary-form of governor and throttle valve and is fixed over the inlet P
for the purpose of regulating the almission of motive fluid to the nozzles R and thus
controlling the speed of the turbine wheel A. Z is a drain or blow off pipe through
which when steam is the motive fluid used, the condensed steam may be drained off at
intervals by the employment of an ordinary blow-off cock, or any sediment which may
have been carried into the duct O with the motive fluid can be blown off, and thus
minimize the possibility of any sediment stopping up the orifice of the nozzles R.
Z Z are plugs screwed into the outside of the casing L, each one immediately
opposite to one of the openings or passages S, so that when unscrewed and removed
they permit of a wire being passed through the orifice of the nozzle 1 to clear away
any dirt that may have been lodged therein.
The action of the turbine may be described as follows:-The motive fluid first
passes through the governor or throttle valve Z into the inlet P along the branch
ducts Q into the duct O and passing through the sumall openings or passages S to the
nozzles R, from the pointed ends of which it issues as jets which are directed into one
end of the buckets G, and after traversing same round the semi-circular or semi-
elliptical curvature forming the back thereof is discharged at the opposite end of the
bucket in a line approximately parallel with and in opposite direct on to that of its
initial flow whereby the kinetic energy of the motive Buid is imparted to the turbine
wheel with a maximum of efficiency and the rotation of the turbine wheel A is thus
effected on its shaft J, on which the pinion T is mounted so as to engage the spur
wheel U mounted on the driving shaft V, whereby the velocity of revolution of the
turbine wheel is suitably reduced and the power equivalently increased in the driving
shaft V, on which the driving pulley W may be mounted.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. In impulse turbines in which the initial flow of the motive fluid driving the same
is directed into the buckets from one or more jet nozzles within their inner circum-
ference and in which both the flow and the return current are on the same side of the
disc or arms of the turbine wheel, the combination with the body of the turbine wheel
of an overhanging annular rim revolving therewith, a circumferential concave groove
of approximately semi-circular cross section in the inner face of said rim, thin sheet.
metal vanes dividing said groove into buckets said vanes being inserted across said
groove into slits cut transversely across the inner face of said rim to the full depth of
said groove and at such an angle to the inner face of said rim that when said vanes
come opposite the jets of motive fluid driving the turbine they are approximately in
parallel line therewith whereby the motive fluid in passing from the inlet to the outlet
end of a bucket is deflected axially round said curve and the return current is
discharged inwardly therefrom in a line approximately parallel with and in opposite
B

page_text: direction to that of its initial flow, and a band around said rim compressing and
holding together the said vanes and the divided portions of said rim, substantially as
and for the purpose set forth.
2. In impulse turbines in which the initial flow of the motive fluid driving the same
is directed into the buckets from one or more jet nozzles within their inner circum-
ference and in which the turbine wheel has an overhanging annular rim formed with a
circumferential concave groove of approximately semi-circular cross section in its
inner face as and for the purpose set forth, the combination with said rim and its
circumferential groove of a second similar groove in said rim parallel with the first
described groove and in sufficiently close proximity to it that their curves meet in a
sharp edge and f rm a wedge like projection between the two grooves, and thin sheet
metal vanes dividing both of said grooves into buckets said vanes being inserted across
said grooves into slits cut transversely across the inner face of said rim to the full
depth of said grooves and at an angle as described whereby when the jets of motive
fluid are directed upon the edge between the two grooves said edge divides it between
the two grooves and it is discharged from the opposite ends of the double buckets
thereby formed in a line approximately parallel with and in opposite direction to
that of its initial flow substantially as and for the purpose set forth.
3. In impulse turbines in which the initial flow of the motive fluid driving the same
is directed into the buckets from one or more jet nozzles within their inner circum-
ference and in which the turbine wheel has an overhanging annular rim formed with
circumferential concave grooves of approximately semi-circular cross section in its
inner face, said grooves being divided transversely into buckets in the manner and for
the purpose set forth, the combination with said turbine wheel and said rim and its
circumferential grooves divided into buckets of another annular rim overhanging the
other side of the turbine wheel and having similar grooves divided by vanes in the
same manner as the first named grooves into buckets but with the vanes set in
the opposite direction to those in the first named grooves whereby the turbines can be
driven in the one direction by means of the buckets in the first named grooves and in
the other direction by means of the buckets in the second named grooves substantially
as set forth.
4. In impulse turbines in which the initial flow of the motive fluid driving the same
is directed into the buckets from one or more jet nozzles within their inner circum-
ference the combination with the body of the turbine wheel of an overhanging annular
rim revolving therewith, a successive series of semi-cylindrical concave faced steps
around the inner face of said rim the concave face of each step forming a back
curvature thereof and each of which steps is at right angles to the line of the jets of
motive fluid when opposite same, thin sheet metal vanes dividing said concave faced
steps into buckets, said vanes being inserted into slits cut transversely across the inner
face of said rim to the full depth of said concave faced steps and at such an angle to
the inner face of said rim that when said vanes come opposite the jets of motive fluid
driving the turbine they are approximately in parallel line therewith, whereby the
motive fluid in passing from the inward to the outward end of a bucket is deflected
axially around the concave face of each step and the return current is discharged in a
line approximately parallel with and in opposite direction to that of its initial flow and
a band around said rim compressing and holding together the said vanes and the
divided portion of said rim, substantially as and for the purpose set forth.
5. In impulse turbines in which the initial flow of the motive fluid driving the same
is directed into the buckets from one or more jet nozzles within their inner circum-
ference, the combination with the body of the turbine wheel of an annular rim
overhanging both sides of same and revolving therewith, a circumferential central
concave groove of approximately semi-circular cross section in the inner face of said
rim, thin sheet metal vanas dividing said groove transversely into buckets said vanes
being inserted across said grooves into slits cut transversely across the inner face of
said rim and into similar slits cut in the periphery of the wheel and at such an angle
to the rim that when said vanes come opposite the jets of motive fluid driving the
turbine they are approximately in parallel line therewith, whereby the motive fluid

page_text: which enters the buckets at one side of the periphery of the wheel is discharged\
therefrom at the opposite side, substantially as and for the purpose set forth.
6. The several combinations of parts of impulse turbines substantially as hereinbefore
described and shown in the drawings.
Dated this 9th day of April 1897
J. C. MEWBURN & ELLIS,
55 and 56 Chancery Lane, London, Chartered Patent Agents.