Improvements in Air Propellers or Ventilating Fans.
Year: 1889

page_text: Date of Application, 15th Oct., 1889
Complete Specification Left 20th Dec. 1889-Accented 25th Jan. 1890
PROVISIONAL SPECIFICATION,
Improvements in Air Propellers or Ventilating Fans.
I WILLIAM SAYER of 144 Uttoxeter New Road Derby in the County of Derby
Engineer do hereby declare the nature of this invention to be as follows
My invention relates to apparatus for propelling exhausting agitating or circulating
air vapour or gases and consists of an improved construction of the blades or wings
used in such apparatus.
Air propellers or ventilating fans usually act in one direction only and are influenced
to a great extent by centrifugal force.
Now by my invention I so construct the blades or wings of my propeller or
ventilator that the peripheral extremities of the same are of T section and by this
means the centrifugal force of the air is to a great extent counteracted and I am
enabled to reverse the direction of revolution and thus use the same apparatus for
either forcing exhausting or agitating a current of air vapour or gas in either
direction at will.
The blades are mounted in or in front of a suitable cylinder or frame actuated by
any well known mechanical means.
Dated this day of October 1889
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Air Propellers or Ventilating Fans.
I WILLIAM SAYER of 144 Uttoxeter New Road Derby in the County of Derby
Engineer do hereby declare the nature of my said 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 relates to apparatus for propelling exhausting agitating or circulating
air vapour or gasses and consists of an improved construction of the blades or wings
used in such apparatus.
Air propellers or ventilating fans usually act in one direction only and are
influenced to a great extent by centrifugal force.
Now by my Invention I so construct the blades or wings of my propeller or
ventilator that the peripheral extremities of the same are of T section and by this
means the centrifugal force of the air is to a great extent counteracted and I am
enabled to reverse the direction of revolution and thus use the same apparatus for
either forcing exhausting or agitating a current of air vapour or gas in either
direction at will.
The blades are mounted in or in front of a suitable cylinder or frame and actuated
by any well known mechanical means.
I do not limit myself to the number of blades or to the exact form of the T shaped
peripheral extremities thereof but any convenient number of blades may be used and
I may find it desirable to cut away a portion of each end of the T shaped peripheral
extremities of each blade and at opposite ends thereof so as to lighten the propeller as
will be seen on reference to figure 3.
Referring to the accompanying drawings and to the figures and letters of reference
marked thereon.
Figure 1 is a front elevation of a four bladed propeller constructed according to my
invention.

page_text: Figure 2 is a transverse sectional elevation of the same and
Figure 3 is a perspective view of a blade constructed according to a modification
of my invention and having portions of its peripheral extremity cut away or
omitted.
In these figures A indicates the framing B the blades mounted on a boss C carried
by a shaft D which may be driven by a belt on the pulley E or by any desirable
method.
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 air propellers or ventilating or like fans the use of blades or wings having their
outer or peripheral extremities wholly or partially of T section substantially as
herein described and illustrated by the accompanying drawings.
Dated this 20th day of December 1889
POPPLEWELL & Co.,
17 & 18, Southampton Buildings, London, W.C., Agents for the Applicant.