NEW OR IMPROVED MEANS AND APPARATUS FOR PRODUCING RAPID MOVEMENT OF FLUID, APPLICABLE FOR THE MEASURE- MENT OF MOTIVE POWER AND OTHER PURPOSES
Year: 1877

page_text: LETTERS PATENT to William Froude, of Chelston Cross, Torquay, in the County
of Devon, for the Invention of "NEW OR IMPROVED MEANS AND APPARATUS
FOR PRODUCING RAPID MOVEMENT OF FLUID, APPLICABLE FOR THE MEASURE-
MENT OF MOTIVE POWER AND OTHER PURPOSES."
Sealed the 24th July 1877, and dated the 24th March 1877.
PROVISIONAL SPECIFICATION left by the said William Froude at the Office
of the Commissioners of Patents on the 24th March 1877.
WILLIAM FROUDE, of Chelston Cross, Torquay, in the County of Devon. "NEW
OR IMPROVED MEANS AND APPARATUS FOR PRODUCING RAPID MOVEMENT OF FLUID,
APPLICABLE FOR THE MEASUREMENT OF MOTIVE POWER AND OTHER PURPOSES."
My Invention relates to means and apparatus whereby a comparatively slow
motion of a revolving shaft is made to produce a very rapid movement of fluid.
By means of certain additions to the said apparatus, whereby the power required
to produce the fluid movement can be measured, the apparatus becomes available
as a dynamometer; also the apparatus may be used as a break, or the movement
of the fluid may be employed for other purposes to which fluid currents are
applicable.
I will describe the apparatus as used for imparting movement to water, it is to
be understood however that other fluids may be operated on by it. It consists of
two parts, a disc on a revolving shaft, which disc I will hereafter term "the wheel,"
and another stationary disc which I will term " the case." Both the wheel and the
case are situated on the same axial line, face to face, and close together, but without
rubbing on each other. In the face of each of them is formed a circular groove
concentric with the axis, the groove being curved in sectional form so as to present
in each case the outline of a half circle, or half ellipse, or a form approximating
thereto, and the groove in each case being at the same distance from the axis, when
the wheel and case are in position, facing and close to each other, the two grooves
together form a channel, circular, elliptical or nearly so, in section, and sweeping
round in a circular course concentric with the axis. In both grooves there are

page_text: fixed a number of diaphragms or thin plates dividing the channel into a number
of cells, and these diaphragms are preferably inclined to the plane of the wheel or
case. The cells being charged with water and kept so charged (which may be done
by immersing the whole in water), the wheel is made to revolve, and this has the
effect of causing the water to rotate in the cells of the wheel and case, forming
therein a succession of vortices. As the revolution of the wheel continues, even at
a moderate speed, the rotary or vortical motion of the water in the channel becomes
more and more accelerated until at a high speed the forces tending to accelerate
the rotation of the vortices become balanced by the friction which tends to retard
them.
As the forces acting within the channel of the wheel and case tend to thrust
them apart, I prefer to construct the apparatus in duplicate forni, making the wheel
with a groove in each of its sides and applying on each side of the wheel a grooved
case, the two cases being tied together so that the thrust on the one side balances that
on the other. When the wheel revolves, producing the vortical motion of the water
in the channel, the case tends to revolve in the same direction as the wheel. By
holding the case stationary by means of a weight, spring, or by a piston or ram
acted on by fluid pressure in opposition to the force which tends to make it revolve,
I am enabled to measure or estimate the amount of motive power which is applied
to drive the wheel. In one or more of the cells of the case groove I provide sliding
or other sluices whereby, when desired, the vortical motion of the water can be
obstructed or arrested, and by this means I can relieve the wheel of more or less
of the resistance to its revolution; also the case may be mounted so that it can be
made to revolve on the same axis as the wheel. When the case is permitted to
revolve in the same direction with the wheel the power required to drive the wheel
is reduced, but when the case is held stationary or made to revolve in the direction
opposite to that in which the wheel revolves, the power required to drive the wheel
is increased. The apparatus can thus be made to operate as a break by varying
the resistance to the revolution of the wheel. By providing suitable apertures in
the case which can be opened when the rapid rotation of the water has been set
up jets or currents at high velocity can be allowed to issue from the case by some
of these apertures, the water thus discharged being replaced by a fresh supply
entering by others of the apertures.
'
Although in what precedes I have described the external part or case as being
stationary whilst the internal part or wheel is made to revolve, it is to be under-
stood that like effects will be produced when the wheel is held at rest and the case
is made to revolve in the opposite direction.
By making the diaphragms, which divide the channels into cells, inclined to thé
plane of revolution, the force required to drive the apparatus in the one direction
is increased, and the force required to drive it in the opposite direction is diminished,
that is to say, it requires greater power to drive the wheel in the direction towards
the mouths of the cells in the case than in the direction away from the mouths, the
difference being dependent on the slant of the diaphragms.
Apparatus acting as above described may be constructed in modified form by
making the curved cells in the outer circumference of a wheel, and in the inner
circumference of an annular case surrounding and enclosing the wheel.
:
:
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Froude in the Great Seal Patent Office on the 21st Sep
tember 1877.
J
WILLIAM FROUDE, of Chelston Cross, Torquay, in the County of Devon., "NEW 50
OR IMPROVED MEANS AND APPARATUS FOR PRODUCING RAPID MOVEMENT OF FLUID,
APPLICABLE FOR T
THE MEASUREMENT OF MOTIVE POWER AND OTHER PURPOSES.”
....

page_text: My Invention relates to means and apparatus whereby a comparatively slow
motion of a revolving shaft is made to produce a very rapid movement of
fluid.
By means of certain additions to the said apparatus, whereby the power required
to produce the fluid movement can be measured, the apparatus becomes available
as a dynamometer, also the apparatus may be employed as a break, or the movement
of the fluid may be employed for other purposes to which fluid currents are
applicable.
"
I will describe the apparatus as used for imparting movement to water; it is to be
understood however that other fluids may be operated on by it. It consists of two
parts, a disc on a revolving shaft, which disc I will hereafter term "the wheel," and
another stationary disc which I will term the case." Both the wheel and the case
are situated on the same axial line, face to face and close together, but without
rubbing on each other. In the face of each of them is formed a circular groove
concentric with the axis, the groove being curved in sectional form so as to present
in cach case the outline of a half circle or half ellipse, or a form approximating
thereto, and the groove in each case being at the same distance from the axis when
the wheel and case are in position, facing and close to each other, the two grooves
together form a channel circular, elliptical or nearly so, in section, and sweeping round
in a circular course concentric with the axis. In both grooves there are fixed a
number of diaphragins or thin plates dividing the channel into a number of cells,
and these diaphragms are preferably incliued to the plane of the wheel or case. The
cells being charged with water and kept so charged (which may be done by immersing
the whole in water), the wheel is made to revolve, and this has the effect of causing
the water to rotate in the cells of the wheel and case, forming therein a succession of
vortices. As the revolution of the wheel continues even at a moderate speed,
the rotary or vortical motion of the water in the cells becomes more and more
accelerated until at a high speed the forces tending to accelerate the rotation
of the vortices become balanced by the friction which tends to retard them.
As the forces acting within the channel of the wheel and case tend to thrust them
apart, I prefer to construct the apparatus in duplicate form, making the wheel with
a groove in each of its sides, and applying on each side of the wheel a grooved case,
the two cases being tied together so that the thrust on the one side balances that on
the other. When the wheel revolves, producing the vortical motion of the water in
the channel, the centrifugal force of the vortices tends on the one hand to resist the
motion of the wheel, and on the other to make the case revolve in the same direction
as the wheel. By holding the case stationary by means of a weight, spring, or by a
piston or ram acted on by fluid pressure in opposition to the force which tends to
make it revolve I am enabled to measure or estimate the amount of motive power
which is applied to drive the wheel. In one or more of the cells of the case groove
I provide sliding or other sluices whereby when desired the vortical motion of
the water can be obstructed or arrested, and by this means I can relieve the wheel
of more or less of the resistance to its revolution; also the case may be mounted
so that it can be made to revolve on the same axis as the wheel. When the case is
permitted to revolve in the same direction with the wheel, the power_required to
drive the wheel is reduced, but when the case is held stationary, or made to revolve
in the direction opposite to that in which the wheel revolves, the power required
to drive the wheel is increased. The apparatus can thus be made to operate as
a break by varying the resistance to the revolution of the wheel. By providing
suitable apertures in the case, which can be opened when the rapid rotation of the
water has been set up, jets or currents at high velocity can be allowed to issue from
the case by some of these apertures, the water thus discharged being replaced by a
fresh supply entering by others of the apertures.
Although in what precedes I have described the external part or case as being
stationary while the internal part or wheel is made to revolve, it is to be understood
that like effects will be produced when the wheel is held at rest, and the case is made
to revolve in the opposite direction.

page_text: Froude's Improvements in Apparatus for Producing Rapid Movement of Fluid, &c.
By making the diaphragms which divide the channel into cells inclined to the
plane of revolution, the force required to drive the apparatus in the one direction is
increased, and the force required to drive it in the opposite direction is diminished,
that is to say, it requires greater power to drive the wheel in the direction towards
the mouths of the cells in the case than in the direction away from the mouths, the
difference being dependent on the slant of the diaphragms.
Apparatus acting as above described may be constructed in modified form by
making the curved cells in the outer circumference of a wheel, and in the inner
circumference of an annular case surrounding and enclosing the wheel.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a vertical section, Fig. 2 a front view, partly in section, and
Fig. 3 a plan, partly in section, of apparatus according to my Invention, applicable
as a dynamometer to test the power transmitted by a revolving shaft, or as a break
to regulate its speed. Fig. 4 represents part of the development of a section taken
on a cylindrical surface, cutting the apparatus at the line Z, Z, of Fig. 1.
The apparatus shewn in these Figures is of double kind, so that all strain in
the direction of the axis is counterbalanced; it is also provided with adjustable
sluices, whereby the resisting force can be regulated as desired. The wheel made
with a large hollow boss b, so that shafts a of various sizes may be conveniently
keyed in it, revolves between the two sides c, c, of the case. The wheel has
on each side of it a circular cavity d, d, semi-elliptical in section, or nearly so,
the said cavity extending round the whole circumference. Each of the sides of
the case has a similar cavity , d. In those cavities are fixed a number of
diaphragms or radiating blades which are inclined to the plane of revolution, as
shewn in Fig. 4. I prefer to make the number of blades in the wheel differ slightly
from the number in the casing, thus, for example, the wheel may have 12 blades in
each cavity, whilst the case has 13, as by such variation I avoid the shocks which
might be produced if all the blades of the one part coincided with those in the other
part. I prefer also to make the inclination of the blades and the section of the
cavities in which they are fixed such that the compartment or cell formed between
each pair of blades is of semi-circular form, or nearly so, on the plane of the blade.
The diaphragms may be flat, as shewn in Fig. 4, but it is advantageous to curve
a little forwards those edges of the diaphragms which meet the liquid as it enters
the cells in its vortical movement. The construction so far as I have described
it is all that is necessary for the operation of the apparatus as a break, that is
to say, the cavities of the wheel and casing being charged with water, when
the shaft a is caused to revolve, the water in the cavities is put into a vortical
rotation which by centrifugal force generates a pressure in the cells between the
blades, tending to retard the wheel and to urge the casing round in the same
direction with the wheel. By applying weights, springs, hydraulic, or other pressure
at points, such as h, to resist the tendency of the case towards rotation, the force
impelling it may be measured, and the velocity of the wheel's rotation being known,
the power applied to move it can be ascertained. In order that the resistance offered
to the rotation of the wheel and the corresponding impulsive force on the case may
be adjusted as desired, I prefer to provide in the casing sliding blades or sluices e, e,
which by means of screws f can be slid more or less inwards across the faces of the
cells. These sluices, by arresting or interrupting more or less the vortical rotation of
the water in the cells of the wheel and case, cause a greater or less reduction of force
which resists the wheel and impels the case. The apparatus when provided with
such sluices may be conveniently applied as a break to control the rotation of a
revolving shaft.
Although I have shewn in the Drawings annexed to this Specification a construc-
tion whereby the cells are formed by partitioning grooves in the faces of the wheel
and case, it is to be understood that they might be otherwise constructed and
arranged. For example, the cells might, as I have mentioned above, be formed in the

page_text: outer periphery of a wheel and the inner periphery of an annular caso surrounding
it. Or instead of forming the cells by partitioning grooves, pipes bent to a U shape
might be employed, such pipes being fixed respectively on a wheel and on a stationary
frame or case in such positions that the mouths of those on the wheel present them-
selves towards the mouths of those on the frame or case.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, I claim,-
First. Producing rapid vortical movement of a fluid from comparatively slow
rotation of a wheel by the use of curved cells containing the fluid so arranged
respectively on the wheel and on its case that the fluid can flow continuously
from the cells of the one set into those of the other set, substantially as herein
described.
Second. The use, as a break or dynamometer, of a wheel and case provided with
corresponding curved cells which are charged with water or other liquid, substantially
as herein described.
Third. The use, in combination with the apparatus referred to in the preceding
claim, of adjustable sluices for regulating the vortical motion of the liquid in the cells,
substantially as and for the purposes heroin sot forth.
In witness whereof, I, the said William Froude, have hereunto set my hand
and seal, this Tenth day of September, in the year of our Lord One
thousand eight hundred and seventy-sevon.
WILLIAM FROUDE. (L.S.)