Improvements in Ventilating Fans.
Year: 1895

page_text: Improvements in Ventilating Fans.
I, JOHN JEFFREYS 11 Old Queen Street Westminster Heating and Ventilating
Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to a fan for forcing air through flues & trunks against
resistance.
The fan consists of any desired number of radiating blades according to size, set
parallel to the axis and mounted on a hub, the lower portion of the blades being
cut away to allow free admission of the air.
The edges of the fan blades on both sides are partly covered by cheeks or bands
having a circular opening on the inlet side to admit the air between the divisions
formed by the blades and the enclosing cheeks.
A suitable hemispherical casing encloses the outside of the fan in which curved
radial guide blades are fixed at an angle of 45° round the internal periphery,
against which the air, discharged by centrifugal force impinges, and is diverted by
the curve of the fixed blades outwards in a direction parallel with the axis.
A diaphragm or cap with rim fitting truly round the internal edges of the fixed
blades is inserted inside the hemispherical casing fitting against the internal face of
the fan, forming a bearing for the axle. The air is delivered between the outer
rim of this cap and that of the hemispherical casing.
To assist the inflow of the air to the fan a conical mouthpiece is provided on the
inlet side with fixed radial guide blades curved to deflect the inflowing air in
the direction of the motion of the fan blades.
Dated this 13th day of December 1895.
JOHN JEFFREYS.
I, JOHN JEFFREYS 11 Old Queen Street Westminster Heating and Ventilating
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 :-
This invention relates to a fan for forcing or exhausting air through flues and
trunks against resistance.
The fan consists of any desired number of radiating blades A according to size,
set parallel to the axis and mounted on a hub B, the lower portion of the blades
being cut away to allow free admission of the air.
A suitable cylindrical casing C encloses the outside of the fan, in which curved
fixed guide blades D are fixed at any suitable angle round the internal periphery,
against which the air, discharged by centrifugal force impinges, and is diverted by
the curve of the fixed blades, outwards in a direction parallel with the axis of the
fan.
A dished diaphragm or baffle plate E is fitted into the back of the fan covering
the centre of the outlet side, leaving a space the width of the fixed guide blades all

page_text: round between it and the cylindrical casing for passing the air discharged by
the fan.
The fixed guide blades pass through this opening and are continued beyond the
face of the diaphragm E to the outside edge of the cylindrical casing.
The cavity formed at the back of the diaphragm receives the electrical motor
for driving the fan when the motive power is electricity.
When the fan is driven by gearing a pulley is attached to whichever end of the
spindle that may be found most convenient.
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.) The application of fixed curved guide blades round the internal periphery of
the cylindrical casing of a fan for expelling or drawing air. }
(2.) The shape & formation of the blades of the fan and cylindrical casing.
Dated this 16th day of June 1896
JOHN JEFFREYS..