Improvements in Fans or Blowers for Producing Air Currents.
Year: 1889

page_text: Date of Application, 12th Apr., 1889
Complete 'Specification Left, 11th Jan., 1890-Accepted, 15th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in Fans or Blowers for Producing Air Currents.
I ALFRED DOUGILL of Great George's Street Leeds in the County of York Engineer
do hereby declare the nature of this invention to be as follows:-
.
My Invention refers more especially to improvements in the blades or vanes of
fans or blowers or in connection therewith; and has for its object to render such
blades or vanes more durable and to increase their efficiency as producers of air
currents.
My invention consists chiefly in forming the sheet iron or other material of which
the blades or vanes are constructed with corrugations, i.e. constructing the blades or
vanes of corrugated sheet iron or other suitable corrugated material. I may arrange
the corrugations to run radially over the vanes or blades, that is in a direction at right
angles to the axis of rotation; or they may be arranged to run longitudinally along
the blades or vanes in a direction parallel to such axis; or lastly which method I
generally prefer, the corrugations may be arranged to run diagonally across the blades
or vanes, that is in a screw or spiral direction around the axis of rotation.
I do not restrict my Invention to any one particular description of fan or blower,
as it is more or less applicable to almost all descriptions of rotary fans or blowers; or
ventilators.
Also I propose to apply my Invention to fans or blowers, in which-the blades are
capable of adjustment to varying angles, or where the blades are straight, concave,
or convex.
Dated th: 11th
Ր A
21 1000
J. CLARK JEFFERSON,
2, East Parade, Leeds, Agent for Applicant.
COMPLETE SPECIFICATION.
Improvements in Fans or Blowers for Producing Air Currents.
I ALFRED DOUGILL of Great George's Street Leeds in the County of York Engineer
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 Invention refers more especially to improvements in the blades or vanes of
fans or blowers, or in connection therewith; and has for its object to render such
blades or vanes more durable, and to increase their efficiency as producers of air
currents.
My Invention consists essentially in forming the sheet iron or other material of
which the blades or vanes are constructed, with corrugations; i.e. constructing the
blades or vanes of corrugated sheet iron or other suitable corrugated material. I may
arrange the corrugations to run radially over the vanes or blades, that is in a direction
at right angles to the axis of rotation or they may be arranged to run longitudinally
along the blades or vanes in a direction at right angles to the centre line of the blade
or vane, or lastly, which method I generally prefer, the corrugations may be arranged
to run diagonally across the blades or vanes, that is in a spiral direction around the
axis of rotation.
It will be evident that my invention is not materially altered if instead of forming
the ridges as part of a corrugated sheet, such ridges are formed by attaching to a
flat vane or blade projecting strips, running in any of the directions across the vane or
blade above mentioned. And I wish it to be understood, that 1 include uneven or
undulating surfaces so formed, under the designation "corrugations" above given.

page_text: I do not restrict my Invention to any one particular description of fan or blower,
as it is more or less applicable to almost all descriptions of rotary fans, blowers,
or ventilators. I also propose to apply my Invention to fans or blowers, in which the
blades are capable of adjustment to varying angles, or where the vanes or blades are
straight, concave, or convex.
My invention increases the efficiency of fans or blowers by increasing the friction
of the air against the vanes or blades, and thus lessens the slip in the case of screw
blades. When my invention is applied to centrifugal ventilators, I prefer to arrange
the corrugations in a radial direction on the blade or vane, since such centrifugal fans
or ventilators act by throwing off the air by centrifugal force. The corrugations
therefore in this direction tend to keep the air current in an outward radial direction,
and lessen the slip from axial or end currents.
And in order that my invention may be more clearly understood, I have annexed
hereto a perspective view of a screw fan, the blades or vanes of which are formed
of corrugated sheet metal, the corrugations running diagonally across the vanes.
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 :-
In rotary fans, ventilators, or blowers, the construction of the blades or vanes with
corrugations substantially as set forth.
Dated this 10th day of January 1890.
J. CLARK JEFFERSON,
2, East Parade, Leeds, Agent for Applicant.