Improvements in Ventilating Fans.
Year: 1887

page_text: Date of Application, 27th May, 1887
Complete Left, 27th Feb., 1888
Complete Accepted, 29th Mar., 1888
Improvements in Ventilating Fans.
I, WILLIAM EDWIN HEYS of 70. Market Street, Manchester in the County of
Lancaster Fellow of the Institute of Patent Agents, do hereby declare the nature of
this invention to be as follows:-
This Invention relates to ventilating Fans, and its object is to increase the capacity
and efficiency of such fans by improvements in the form and construction of their
blades or vanes.
In carrying out this Invention, in a flat circular plate of suitable metal there are.
cut three or other suitable and convenient greater number of radial, or approximately
radial slits having a length less than four fifths of the radius of the disc. From the
outer end of each radius the plate is also cut in a curved line to the inner end of the
adjacent radius, thus removing from the plate as many pieces of metal as there were
radial slits and leaving the same number of flat blades or vanes. The central portion
of the disc may or may not be slightly dished but in either case that edge of each
blade which joins two radii is curved or bent parallel with the chord of the arc of
curvature of the edge or with a curved or straight line diverging from the curved
edge of the blade to an intermediate point on its radial boundary.
The set of blades or vanes thus forined and constructed is mounted upon a suitable
spindle and framing and may be rotated by the usual means.

page_text: improvements in уедитаыць гаць.
I WILLIAM EDWIN HEYS of 70 Market Street Manchester in the County of
Lancaster Patent Agent 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 :-
The object of this Invention is to increase the capacity and efficiency of ventilating
fans by improvements in the form and construction of their blades or vanes.
The appended sheet of drawings will enable this Invention to be more readily
understood and carried into effect.
Fig. 1 is a plan of a set of vanes in the first stage of construction.
Fig. 2 is a plan of the vanes after having been bent to the required shape, and
drilled for mounting upon the axis.
Fig. 3 is a section along the line A B. Fig. 2.
Fig. 4 is a front view of a completed fan fixed ready for working.
Fig. 5 is a vertical section of Fig. 4. and Fig. 6 is a perspective view.
In a disc of sheet metal of suitable dimensions there are cut three or other greater
convenient number of radial or approximately radial slits having a length less than
four fifths of the radius of the disc. From the inner end of each radial slit a cut is
made through the disc to a point on the circumference of the disc at or near to the
preceding or the following radial slit according to the direction of rotation desired
for the fan. This cut must be curved for the whole or for a part of its length as
indicated at E E Fig. 1. By this method a blank is produced resembling that
represented in Fig. 1. and having three or other greater convenient number
of vanes C.
It is evident that the blank may be stamped out of the solid sheet instead of being
shaped by a series of cuts. The blank is now drilled and perforated as represented
in Fig. 2, for the passage of the shaft and for the passage of the bolts which are to
secure it to the washer or box by means of which it is secured to the shaft in the
usual manner or the blank may be drilled and perforated at another stage. The blank
may if desired be slightly dished, but it is generally preferred to leave it flat. The
convex portion of each vane is now bent as represented in Figs. 2 and 3, the curvature 3
of each bend commencing on a straight line joining the inner end of the radial or
leading edge to a point at or near the outer end of the contiguous edge, on the
circumference of the disc. In Fig. 2 the dotted lines indicate the original form of
the blank. The degree of curvature given to the following edges of the vanes is
preferred to be about equal to that represented in Fig. 3, but it may be somewhat a
more or less.
In each of the Figures where the letters of reference occur, C indicates the vanes;
D the radial or leading edges of the vanes; and E the curved or following edges of
the vanes.

page_text: The set of vanes constructed from sheet metal as herein before described is mounted
upon a shaft or spindle and is thereby carried and rotated in a suitable framing as,
and by the means, ordinarily employed and well understood. It is however preferred
to carry the bearings for the spindle in bridge fixings as represented at F and F¹
Figs. 4 and 5 as by this arrangement the current of air is interfered with to a less
extent and the bearings are very accessible.
In Fig. 6, the vanes are represented as being constructed to rotate in the opposite
direction to that of those shewn in Figs. 1 2 3 and 4.
It is desired to be understood that the present invention does not relate to any
part of the framing or bearings of ventilating fans.
Having now particularly described and ascertained the nature of my said Invention
as communicated to me from abroad, I declare that what I claim is :-
(1) In a ventilating fan having three or a greater convenient number of vanes,
constructing the vanes with a straight leading edge and a curved and bent following
edge or portion; substantially as hereinbefore described and as illustrated by the
accompanying drawings.
(2) In a ventilating fan, a set of three or a greater convenient number of vanes,
each vane being shaped and constructed as hereinbefore described and as illustrated
by the accompanying drawings.
Dated this 25th day of February & D 180e