Improvements in Revolving Vanes or Propeller Blades.
Year: 1895

page_text: Date of Application, 24th May, 1895
Complete Specification Left, 24th Feb., 1896-Accepted, 24th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in Revolving Vanes or Propeller Blades.
I JAMES MILLEN ADAM of Ibrox Iron Works, Glasgow, Member of the
Institute of Engineers and Shipbuilders in Scotland, do hereby declare the nature
of this invention to be as follows:-
This invention relates to revolving vanes or blades applicable for ships propellers,
aerial machines, air impellers, and for such like apparatus.
In investigating the nature of revolving vanes or blades transmitting motion to
fluids by reaction perpendicular to the plane of gyration I have discovered that
segments of the cone offer theoretically perfect forms for such vanes or blades.
If a hollow cone be passed over an axis or shaft and fixed by one of its sides
longitudinally to the said shaft, and the shaft be made to revolve carrying the cone
with it, that side of the cone which is concave to the direction of gyration presents
a surface upon which may be plotted the outline of a vane or blade constructed on
the principle of this invention. That part of every plane of gyration which passes
through such a cone would of course cut it elliptically, the centre of notion being
toward one end of the major axiч.
.
Considered as a screw it is obvious that that side of the cone which is attached
to the shaft has practically no "pitch" as it lies parallel to the axis perpendicular
to the plane of gyration; at the diametrically opposite side of the cone the pitch
is also nil. as every point on such side has a tangent which is common to an arc of
gyration. But between these two extremes a line can be found giving with
precision any required pitch for the cutting or entering edge, and lines drawn
behind the first, i.e., nearer the base of the cone, will give increasing pitches of
perfect symetry, therefore any percentage of slip required can be represented in
the breadth of the blade itself, the entering edge being normal to the speed, and a
segment of a cone so found will form a theoretically perfect vane, or propeller
blade.
Such a segment bears a remarkable resemblance to the form of a bird's wing
outspread and suggests.the suitability of vanes or blades of this form for aerial
machines and air impellers as well as for ships propellers and the like apparatus.
The reaction or stream lines are spiral in relation to the moving cone, and
parallel to the axis of shaft the action of the ellipse sweeping in on the circle
around the shaft tending to counteract centrifugal motion in the fluid.
In revolving vanes or blades constructed and set according to this invention the
whole area will be uniformly effective and the carrying around of the fluid will be
minimised. Also as the working face is a developable surface the vane or blade
can be easily and accurately projected for any required duty and in certain cases
formed out of a rolled plate, further the founders patterns can be struck from a
thin metal sheet to form the working face and the patterns themselves thus
produced cheaply and with an accuracy hitherto unattainable in general practice.
Dated this 24th day of May 1895.
F. W. GOLBY,
36 Chancery Lane, London, W.C., Patent Agent for the Applicant.

page_text: атрабуешения щ пevorving vales or Frорепег blades.
I, JAMES MILLEN ADAM, of Ibrox Iron Works, Glasgow, 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 vanes or blades applicable to air impellers and fans,
wind mills, anemometers, ship propellers, turbines, current or speed indicators, and
to similar apparatus designed for transmitting motion to or receiving rotary motion
from fluids by reaction.
In investigation the nature of revolving vanes or blades transmitting motion to
fluids by reaction perpendicular to the plane of gyration I discovered that segments
of the cone in certain positions seemed to offer theoretically perfect forms for such
vanes or blades, owing to the cyclic character of the figure giving low tangential
angles down to zero, whereby a fluid at rest may be entered or a current deflected
without shock.
If a hollow cone be passed over an axis or shaft and fixed by one of its sides
longitudinally to the said shaft, or to a boss thereon, and the shaft be made to
revolve carrying the cone with it, one side of the cone presents a surface upon
which may be plotted the outline of a vane or blade constructed on the principle of
this invention. The axis of a cone so fixed is inclined to the axis of gyration,
hereinafter called the shaft axis. This inclination of the cone produces the
reactive quality in the vane or blade; the greater the inclination, as the perigee
edge approaches the shaft axis, the more pronounced will be the reactive surface,
or in other words, the greater will be the potential pitch ratio. The required vane
will be contained in one side or half cone as divided by the plane of inclination.
The pitch lines of a rotating half cone correspond to the figure of cylinders
concentric to its shaft axis intersecting the cone surface, and are found to be
symmetrical curves of increasing pitch from zero at apogee toward a point near to
perigee where the curve gradually reverses to a decreasing pitch reverting to zero.
Every pitch line is necessarily identical in form differing only in scale of magnitude
and all contiguous lines produced by the same movement being identical in direction,
currents similarly produced will be homogeneous.
It is demonstrable that the theoretical pitch lines above described offer the path
of least resistance to a fluid acted upon by the half cone rotating with the apogee
as leading edge, the reaction being rather centripetal and counteractive of
centrifugal motion in the fluid.
The generating angle of the cone employed will modify the longitudinal
inclination of the vanes or blades to the shaft.
In proceeding to construct vanes or blades on the principle above indicated, a
cone of the generating angle and the inclination determined upon, is drawn down to
scale. In the accompanying drawings I have shown how a vane or blade constructed
according to my invention may be produced, and, by way of example, have
illustrated with a cone having a generating angle of 75° the apex of which is
upon the shaft axis and the perigee edge inclined 15° therefrom.
Figure 1 is a side elevation of the cone A.M P. A0 is the axis of the cone
and A N the shaft axis. Generating lines are shown spaced 15° and numbered
from perigee to apogee 0° to 180°. The cone is further divided by twelve circular
planes from apex to base marked C 1, C 2,-C 12, and by twelve equidistant
planes of gyration cutting ellipses through it marked E 1, E 2,-E 12.
Figure 2 is an end elevation of the same, showing on left hand side the above
mentioned generators 0° to 180° and the circular planes C 1 to C 12.
On the right
hand side in reverse are shown certain of the ellipses, viz.; E 3, E 4, E 5, and E 6.

page_text: Passing through these circular planes and ellipses are drawn eight circular arcs
concentric to the shaft axis representing pitch lines or cylindrical intersections or
stream lines, all as before described. These circular arcs are lettered b to j and
are plotted with similar reference letters across the surface of Figure 1.
Fig. 3 is a diagram of curves representing the above mentioned cylindrical
intersections unrolled or developed and showing the true pitch curves across the
conic surface upon the lines b toj respectively. Upon each of these curves two
points are marked off, L representing the leading edge and F representing the
following edge of a blade suitable for a ship propeller. A nominal mean pitch
may be struck by a chord drawn from L to F, as is shown by the chord z u drawn
through the points L and F of the curve g.
It is obvious that the pitch of any point may be easily found relative to the
horizontal W Y and to the radius, and a desired pitch fixed with precision and any
width of blade determined to suit the purpose required.
Reverting to Figs. 1 and 2. The side and end elevations of a propeller
blade R S T, corresponding to the pitch lines found on Fig. 3, are superimposed
upon the conic figures, showing also a suitable boss Q.
Fig. 4 shows the development of the conic surface and the superficies of the same
vane or blade R S T plotted thereon.
In proceeding to manufacture vanes so designed constructed of sheet or rolled
plates, the metal must be cut to the required form and may then be curved upon a
rigid cone in the true position determined.
Foundry work need not differ much from ordinary practice. To mould a ship's
propeller in loam the mould may be swept up by a rod guided over the corresponding
surface of a small template cone fixed in position at the apex, and shifted round for
each blade.
Where patterns must be used, these may be accurately formed by cutting a thin
metal plate or plates to the proper shape for one or both faces, curving the same
upon a rigid cone, and using it or them for facing, and filling up thereupon the
required thickness with any suitable material.
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. Vanes or propeller blades constructed on the projection of a cone inclined to
the axis of gyration substantially as described.
2. Vanes or propeller blades of the kind indicated in the preceding claim
produced by cutting sheet or rolled plates to the required outline and curving same
to fit the surface of a rigid cone in the true position determined substantially as
described.
3. Moulding patterns (for casting vanes or propeller blades of the kind indicated
in Claim 1 hereof or propellers having such blades) constructed by forming the
facing plates thereof of sheets cut from any sufficiently rigid material and curved
upon a conic surface and filled up to the thickness required for the casting with
any suitable material, substantially as described.
Dated this 24th day of February 1896.
F. W. GOLBY,
36 Chancery Lane, London, W.C., Patent Agent for the Applicant.