Year: 1887

page_text: Date of Application, 18th May, 1887.
Specification Accepted, 21st June, 1887.
I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. 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 the present invention is to design an improved air propeller which
may surpass others known and used up to the present time as regards simplicity of
construction and efficiency of action.
In the accompanying drawings Figure 1 represents the improved air propeller in
cross section on line L-M of Figure 5.
Figure 3 is the same with the wings D D¹ D' D³ and the drum F having made a
revolution of 45°.
Figures 2 and 4 represent similar views with the drum F being of different form
in section.
Figure 5 is a side elevation partly in section.
Figure 6 is a detail of the wings.
Figure 7 is a detail of the drum.
Figure 8 represents a front view of the bearing.
Figure 9 is a longitudinal section of the same."
Figure 10 is a front view of the split sleeve forming part of the bearing.
The outer casing A forms two chambers the upper one of which is larger than the
lower one and both of which are closed separately by well fitting covers B B and C C.
A disc E having two or three or as represented four wings D D1 D2 D³ is mounted
on a shaft well journalled in bearings in the covers B B and provided at one end with
a spur wheel which gears with another spur wheel z¹ on the end of shaft g carrying
the drumm F in the lower chamber in such a manner that drum and disc make an
equal number of revolutions or that the disc makes three while the drum makes
four.
2

page_text: The covers B have cylinders G G₁ attached to them which reach so far into the
casing as to leave just sufficient room for the disc E to revolve between them.
The longitudinal concavities ab of the cylinders G G¹ are exactly concentric with
the drum and are in such proportion to the channels c d e of the drum F that when
one of the channels stands opposite the concavities ab the latter entirely cover the
channel and even overlap it (Figure 1). -
To the disc E are fixed the wings D D1 D2 D3 which fit between the outer casing A
and the cylinders G G and revolve with the said disc E. During the driving of
the apparatus these wings will enter into and pass through the channels c d e of the
drum F and are constructed accordingly. The drum F is somewhat longer than
the wings D-D³ and is provided on both ends with a discf fitting closely against
the covers C.
To ensure a perfect engagement without touching of the wings D-D³ and the
channels c d e the disc E is constructed with tappets engaging with corresponding
recesses in the middle of the drum F Figure 7 which are of the same width as the
disc E thus forming a perpetual tight joint. To prevent too much pressure or
friction the recesses of the drum F may be provided with any suitable elastic
packing.
It will be seen from this description that contrary to the other known apparatus
in this construction the tight joint where friction takes place is restricted to the narrow
disc E.
The above mentioned bearings for the shaft of the disc E and the axle gg of the
drum F are adjustable and consist essentially of two conical sleeves h and i arranged
within each other and the inner one i of which is split so that when the outer one h
is driven in the inner one i is forced to adopt a smaller diameter. In this manner the
sleeve is forced to fit well around the shaft or axle again when it has become a little
loose through wear and tear. To prevent unequal strain the inner sleeve i is pro-
vided with wedge shaped ribs or feathers 11. The sleeves are placed in hubs or
bosses m of the covers B B and C C and are prevented from turning by the pin n
engaging with a groove o of the hub m. To prevent a longitudinal movement the
sleeve i bears against an annular projection p of the hub at its inner end and against
the cover
at its outer end. The cover q is fastened to the hub by two screws r
Figure 8 and prevents the entering of dust and the escape of the oil.
The bearing is adjusted by means of the male screw on the outer end of sleeve h
and the nuts provided with notches; the latter is held against the hub by the
cover q. Instead of the inner sleeve the outer sleeve may be made rigid and the inner
adjustable.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed I declare that what I claim is :—
1. In a rotary air propeller such as described above the cylinders G G¹ fixed to the
covers with the concavity a b of which the drum F remains continually in contact so
that the inlet and outlet passages are continually cut off from each other substantially
as and for the purpose specified.
2. In a rotary air propeller an adjustable bearing consisting of two sleeves such
as hi arranged one inside the other one of which is split in its longitudinal direction
so that the diameter thereof is altered if either of the sleeves is moved longitudinally
substantially as and for the purpose specified.
Dated this 18th day of May 1887