IMPROVEMENTS IN THE CONSTRUCTION OF VENTILATORS AND FANS
Year: 1879

page_text: LETTERS PATENT to Jolin 'Albert Reinhold Hildebrandt, of Manchester, in the
County of Lancaster, Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF VENTILATORS AND FANS." A
communication from abroad by 'Friedrich Pelzer, of Dortmund, in Germany,
'Civil Engineer.
Sealed the 9th March 1880, and dated the 11th September 1879.
PROVISIONAL SPECIFICATION left by the said John Albert Reinhold
Hildebrandt, at the Office of the Commissioners of Patents on the 11th
September 1879..
JOHN ALBERT REINHOLD HILDEBRANDT, of Manchester, in the County of
Lancaster, Engineer and Patent Agent. "IMPROVEMENTS IN THE CONSTRUCTION OF
VENTILATORS AND FANS." A communication from abroad by Friedrich Pelzer, of
Dortmund, in Germany, Civil Engineer,
८ The object of the improvements is to lessen the difficulties in the construction of
ventilators and fans by obviating the screw surfaces of the vanes, and still obtaining
results which are as good if not better than those obtained by fans or ventilators
constructed with screw surface vanes.
The vanes or the body proper of the ventilator are put by preference on. the free
end of a shaft carried in proper bearings and driven in a convenient manner, the
body facing the air canal or shaft from which the ventilator is to draw. The
shape of the body of 'the ventilator is for a short length cylindrical, and it then
runs out to a point at a very obtuse angle, the point itself being usually formed by
a 'cast iron boss, the 'last named conical part usually projecting into the air canal
and the cylindrical part being outside. The vanes form part of planes, which, if
uniformly distributed over the circumference of the ventilator, will intersect the
centre line of the shaft at a point and at an angle while the intersection of these
planes form two pyramids which have a common 'axis and apex in the centre line
of the shaft.
⚫ "The vanes are formed by fixing angle iron arms on the edges of the base of the
aforesaid coneshaped boss and then riveting sheet or plate iron to these arms to
form the continuation of the sides of the pyramids and fixing the back edge of the
said sheets or plates directly on a coneshaped back plate of sufficient strength which
is nearly or quite parallel to the angle of the vanes, & which is open in the
centre.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Albert Reinhold Hildebrandt in the Great Seal Patent
Office on the 11th March 1880.
JOHN ALBERT REINHOLD HILDEBRANDT, of Manchester, in the County of
Lancaster, Engineer and Patent Agent. "IMPROVEMENTS IN THE CONSTRUCTION OF
VENTILATORS AND FANS." A communication from abroad by Friedrich Pelzer, of
Dortmund, in Germany, Civil Engineer.
The object of the improvements is to lessen the difficulties in the construction of
ventilators and fans by obviating the screw surfaces of the vanes, and still obtaining
results which are as good if not better than those obtained by fans and ventilators
constructed with screw surface vanes. The vanes of the body proper of the
ventilator are put by preference on the free end of a shaft carried in proper bearings
and driven in a convenient manner, the body facing the air canal or air shaft from
which the ventilator is to draw. The shape of the body of the ventilator is for a
short length cylindrical and it then runs out to a point at a very obtuse angle, the
point itself being usually formed by a cast iron boss, the last named conical part
usually projecting into the air canal and the cylindrical part being outside. The
vanes form part of planes, which, if uniformly distributed over the circumference
of the ventilator, will intersect the centre line of the shaft at a point and at an
angle, while the intersection of these planes form two pyramids which have a
common axis aud apex in the centre line of the shaft. The vanes are formed by
fixing angle iron arms on the edges of the base of the aforesaid coneshaped boss and
then riveting sheet or plate iron to these arms to form the continuation of the sides
of the pyramids and fixing the back edge of the said sheets or plates directly on a
cone shaped back-plate of sufficient strength which is nearly or quite parallel to the
angle of the vanes, and which is open in the centre.
In order to describe the Invention more fully I show an exhaust fan on the
accompanying Drawing which I will now proceed to explain.
DESCRIPTION OF THE DRAWING.
Fig. 1 is a view of the fan as seen from the airshaft or flue; Fig. 2, a side view ;
Fig. 3, a back view as seen from the bearing end; and Fig. 4, a foundation plan.
K is the exhaust or air shaft, or flue, constructed in brickwork or other suitable
material; C is the frame carrying the bearings, and in it the spindle or shaft A on
which is fixed the driving pulley B. The body of the fan generally is denoted by
F and the vanes are marked v, while the conical back-plate or disk to which the
back of the vanes are attached is denoted by a, b, b, c, and k is the solid finishing
cone to which the front edges of the vanes are fixed at m, n.
In Figs. 1 and 3 a modification is shown by which any currents that are thrown
ín a downward direction by the vanes may be prevented from having a counter
effect. It consists of the feather L constructed of brickwork and sheeting sur-
rounding the fan to the extent of about one third of the circumference at the end
of the airshaft by a spiral curve 8, which, with the curve r, forms the edge e.
The fan is equally adaptable for blowing purposes instead of an exhauster, by
constructing it with a double cone, that is to say, by placing two of the fans shewn
back to back, and enclosing in a suitable casing of the well known description.
Having now particularly described the Invention, and ascertained the manner in
which the same may be carried out in practice, I desire it to be understood that I
do not limit myself to the exact details, forms, proportions, and other particulars

page_text: shown or described for the purpose of explanation; but I claim as my Invention
any imitation thereof, and I claim substantially,-
The construction of ventilators or fans substantially as shewn and described in
which the vanes form planes, or nearly so, at an angle with the axis of the
machine.
In witness whereof, I, the said John Albert Reinhold Hildebrandt, have here-
unto set my hand and seal, this Tenth day of March, in the year of our
Lord 1880.
J. A. R. HILDEBRANDT. (LS.)