Improvements in Air Propellers or Fans.
Year: 1894

page_text: Date of Application, 16th July, 1894
Complete Specification Left, 13th Apr., 1895-Accepted, 18th May, 1895
Improvements in Air Propellers or Fans.
We, JOHN DALBY SUTCLIFFE, Engineer, and WILLIAM CASMEY, Engineer,
both of Todd Street, Manchester, in the County of Lancaster, do hereby declare
the nature of this invention to be as follows:-
This invention, is designed to provide an air propeller or fan capable of delivering
an air current more evenly distributed over the whole area and greater in volume
and for less.power also overcoming greater resistance than many of those at present
constructed.
It consists essentially in constructing the blades of special shape curved both
transversely and longitudinally with a hood or flange at the periphery and mounting
such blades to incline towards the delivery side of fan and at a suitable angle or
pitch to deliver the air current in a line parallel to its axis of rotation and increase
the volume of air delivered towards the centre of the propeller.
In carrying out the invention we construct each blade curved transversely
from front to back, the back edge being slightly curved forward to check the
centrifugal tendency and project the current out in a direction parallel to the
axis and curved longitudinally from the base to the periphery preferably forming
the are of a circle the peripheral portion being formed with a curved hood or
flange which also checks the centrifugal tendency of the air current from the
periphery and directs it in a direction parallel with the axis.
The blades of the fan are set at an angle or inclined forwards towards the
delivery side and are attached by a central rib or the like to a single boss being
angularly disposed in relation thereto with any desired amount of pitch.
The boss is preferably constructed with a projecting disc inclined in the same
direction as the blades so that the rib to which the blades are attached may be
straight and bolted or riveted thereto. The disc of the boss may however be
at right angles to the shaft and the rib of the blade be bent or cranked to the
desired degree.
At the delivery side the flanges of the blades are attached to an annular frame
to hold them firmly in position.
By this construction of fan we consider that the following advantages are
gained
(a) A greater amount or volume of air is delivered for less power.
(6) More air is passed through near the centre or boss.
(c) The pressure is more evenly divided over the whole area.
(d) The current of air is driven parallel or approximately parallel with the
axis of rotation.
(e) A greater resistance can be overcome without increase of power.
Dated this 14th day of July 1894.
D
HOUSAN Q. Co

page_text: improvements in Air Propellers or Fans.
We, JOHN DALBY SUTCLIFFE, Engineer, and WILLIAM CASMEY, Engineer,
both of Todd Street Manchester, in the County of Lancaster do hereby declare
the nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :--
This invention is designed to provide an air propeller or fan capable of delivering
an air current of greater volume or force and more evenly distributed over the
whole area or disc of movement with less expenditure of power than any of those
at present constructed.
It consists essentially in constructing the blades of special shape curved both
transversely and longitudinally with a hood or flange at the periphery and
mounting such blades to incline towards the delivery side of fan at such an angle
or pitch and of such a curve as to deliver the air current in a plane parallel
to the axis of rotation and increase the volume of air delivered towards the centre
of the propeller.
The invention will be fully described with reference to the accompanying
drawings.
Fig. 1. Elevation from the back.
Fig. 2. Transverse sectional elevation on line -.
Fig. 3. Back elevation of the hub or boss.
Fig. 4. Sectional elevation of boss.
Fig. 5. Frout elevation of boss.
Fig. 6. Elevation of single blade from the back.
Fig. 7. Side elevation of forward edge of same partly in section on line x-y
Fig. 6.
Fig. 8. Sectional elevation on line - Fig. 6.
Fig. 9. Sectional elevation on line w―w Fig. 6.
Fig. 10. Sectional elevation on line v- Fig. 6.
Fig. 11. Side elevation of hinder edge of the blade looking in the reverse
direction.
Fig. 12. Section on line u-u Fig. 6.
Fig. 13. Section on line t-t Fig. 6.
Fig. 14. Elevation looking from the base towards the periphery.
The fan or air propeller will be constructed with any desired number of blades,
preferably about six, and each blade A will be of precisely similar construction
and shape attached at the base to the boss B and at the periphery to an annular
frame C on the delivery side to hold them firmly in position. We will therefore
describe one blade as the description of it will refer to all.
The blade A is formed of sheet metal curved transversely from the hinder to
the forward edge and longitudinally from the base to the periphery. The blank
from which the blade is shaped is formed with two sides or edges inclined to the
other the side or edge a being considerably longer than the side or edge a¹. In
consequence of the inclination of the two edges a and a¹ the top is much wider
than the base a¹. The side a¹ which forms the hinder edge of the blade is nearly
or approximately straight and the forward edge a is curved to a considerable
extent (see Fig. 7) the curvature gradually increasing from the edge a¹ (sce
Figs. 7 to 11) consequent upon the greater length of the edge a and the top being
brought down to the annular frame C thus forming a hood or flange cat the
periphery gradually increasing in depth from the hinder edge a¹ to the forward
edge a. The base of the blade A is also curved slightly and the curve of the
blade is gradually increased towards the periphery, Figs. 13 and 14.

page_text: The blades A of the fan are all set at an angle or inclined forwards towards the
delivery side and are attached by a central rib D or the like to a single boss R
being angularly disposed in relation thereto with any desired amount of pitch.
The boss B is preferably constructed with a projecting disc b inclined in the
same direction as the blades so that the rib D to which the blades are attache !
may be straight and bolted or, riveted thereto. The disc of the boss may however
be at right angles to the shaft and the rib of the blade be bent or cranked to th
desired degree.
The forward inclination of the back edge a¹ of the blades and the hool or flange
formed near the periphery checks the centrifugal tendency of the current of air
propelled through the fan and projects it out in a direction parallel to the axis of
rotation, and the curved shape of the blade offers less resistance to the passage of
the air than would any sharp or angular bend such as has hitherto been employed.
The angular arrangement or pitch of the blade with no large or obstructing boss
also allows of a current of air being propelled forward from every point of the
surface of the blade.
By this construction of fan we find that the following advantages are
gained:
(a) A greater amount or volume of air is delivered in proportion to the
power employed.
(b) More air is passed through near the centre or boss.
(c) The pressure is more evenly divided over the whole area.
(d) The current of air is driven parallel or approximately parallel with the
axis of rotation.
(e) The air is propelled forward with greater force and a greater resistance
can be overcome without a proportionate increase of power.
(f) The fan runs nearly noiselessly.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. An air propeller or fan constructed with blades curved both transversely and
longitudinally with a curved hood or flange formed at the periphery the blades
being inclined towards the delivery side of the fan to deliver the air current
parallel to the axis of rotation substantially as described and shown.
2. An air propeller or fan constructed substantially as herein described and
illustrated in the drawings.
Dated this 28th day of November 1894.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.