Year: 1898

page_text: I, FRED HATTERSLEY PICKARD, of Belle Vue Road, Leeds, in the County of
York, Engineer, do hereby declare the nature of this invention to be as follows;-
The object of this invention is to so construct air propellers that the blades
secure the maximum propulsion, and eddies and back currents commonly en-
countered in fans hitherto employed are reduced to a minimum, thus enabling
a large volume of air to be dealt with for the least expenditure of power.
According to my invention, I employ a boss which is mounted on a shaft carried
in journals in a suitable framework. The shaft also carries a pulley or other
suitable means for transmitting motion to the propeller, and the exterior of the
journals, the boss and the pulley, are given a form somewhat similar to that of
a cigar, the surface being smooth without unnecessary gaps or irregularities. The
blades are set back in the direction of the intake of the air, and the form of the
said blades is such that an increasing pitch is obtained, and the air is propelled
in a longitudinal direction parallel with the axis of the propeller. The blades
may be attached to the boss by means of suitable flanges set at the required angle,
and the said blades are so situated in relation to the frame that the boss may be
taken off the shaft and turned round, thus enabling the propeller to drive the
air in the reverse direction.
The inclination of the blades to the axis of the propeller enables the air to
traverse their surfaces for the shortest distance and to leave on the opposite side
without permitting the centrifugal force of the air to keep it in prolonged contact
with the surfaces of the said blades, thus reducing the skin friction to a minimum;
and the said inclination of the blades has also the effect of causing the centrifugal
force set up in the metal of which the blades are composed, to counteract the
backward force on the blades exerted by the air, thus making the fan run
smoothly and with the least vibration. The smooth and regular form of the boss
and adjacent parts gives small resistance to the air and prevents the formation
of eddies and counter currents, which have hitherto proved so detrimental to the
efficient working of air propellers.
1000

page_text: improvements in or connected with Air Propellers.
I, FRED HATTERSLEY PICKARD, of Belle Vue Road, Leeds, in the County of
York, Engineer, do hereby declare the nature of this invention and in what man-
ner the same is to be performed, to be particularly described and ascertained in
and by the following statement ;-
The object of this invention is to so construct air propellers that the blades
secure the maximum propulsion, and eddies and back currents commonly en-
countered in fans hitherto employed are reduced to a minimum, thus enabling
a large volume of air to be dealt with for the least expenditure of power.
In order that my invention may be clearly understood, I will proceed to
describe same with reference to the accompanying drawing, in which similar
letters refer to like parts in both figures.
Figure 1 is a front elevation, and Figure 2 is a transverse section of a pro-
peller constructed in accordance with my invention.
According to my invention, I employ a boss A which is mounted on a shaft B
carried in journals C in a framework D. One of the journals C is extended to C¹
so that its end is contained within the boss A, and the other journal C is extended
to a cup C2, thus the extremities of each journal are covered and the bearings are
made dust proof. The shaft B also carries a pulley E; and the exterior of the
journals C, the boss A, and the pulley E, are given a form somewhat similar to
that of a cigar, the surface being as smooth as possible without unnecessary gaps
or irregularities. G are the blades which are set back in the direction of the in-
take of the air, and the form of the said blades is such that the pitch gradually
increases longitudinally from the feed edge G¹ to the discharge edge G2. The
blades are attached to the boss A by means of suitable flanges H, set at the re-
quired angle, and the said blades G are so situated in relation to the frame that
the boss may be taken off the shaft and turned round, thus enabling the pro-
peller to drive the air in the reverse direction. K is a hoop of angle iron, which
holds the ends of the blades firmly in their proper position, and I prefer to form
the blades in such a manner that their profile on the discharga side forms an arc,
Thus assisting the blades in securing the maximum results.
The inclination of the blades G to the axis of the propeller, enables the air
to traverse their surfaces for the shortest distance and to leave on the opposite
side without permitting the centrifugal force set up in the air to keep it in pro-
longed contact with the surface of the said blades, thus reducing the skin friction
to a minimum; and the said inclination of the blades has also the effect of causing
the centrifugal force set up in the metal of which the blades are composed, to
counteract the backward force on the blades exerted by the air, thus making the
propeller run smoothly and with the least vibration. The smooth and regular
form of the boss and adjacent parts gives small resistance to the air and prevents
The formation of eddies and counter currents, which have hitherto proved so detri-
mental to the efficient working of air propellers.
Although I have described my propeller as being driven through the medium
of a belt pulley E, it must be clearly understood that I could equally well employ
an electro motor; or if desired, any other suitable means might be employed.
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 an air propeller, the blades G set back towards the intake of the air, sub-
stantially as and for the purposes set forth.

page_text: 2. In an air propeller, the blades G set back towards the intake of the air and
having their surfaces formed at an increasing pitch longitudinally, substantially
as and for the purposes set forth.
3. In an air propeller, the combination of the boss A, shaft B, journals (', and
pulley E, in such a manner that their surfaces are in a regular and smooth form,
substantially as described.
4. The combination of the boss A, shaft B, journals C, frame D, pulley E or
its equivalent, blades G, flanges H, and hoop K, substantially as and for the
purposes set forth.
Dated this 3rd day of December 1898.
BREER & SON,
London and Leeds, Agents for the Applicant.