IMPROVEMENTS IN SCREW PROPELLERS FOR PROPELLING SHIPS AND OTHER CRAFT
Year: 1876

page_text: LETTERS PATENT to Friedrich Henrich Bierent Babbe, of Antioch, in the
County of Contra Costa, and State of California, one of the United States of
America, for the Invention of "IMPROVEMENTS IN SCREW PROPELLERS FOR
PROPELLING SHIPS AND OTHER CRAFT."
COMPLETE SPECIFICATION filed by the said Friedrich Henrich Bierent Babbe
at the Office of the Commissioners of Patents on the 15th May 1876.
FRIEDRICH HENRICH BIERENT BABBE, of Antioch, in the County of Contra Costa,
and State of California, one of the United States of America. "IMPROVEMENTS IN
SCREW PROPELLERS FOR PROPELLING SHIPS AND OTHER CRAFT."
My said Invention relates to an improved construction of propelling blades, and
means for attaching the same to the shaft by which it is operated, whereby much
less "slip" and "cut up" of the water is had, and the screw be operated with much
less resistance than other devices for the same purpose.
This Invention consists mainly of a disk cut in halves, each half of which being
connected by a stout short arm to a hub or nave. The positions of the blades with
reference to the hub and each other are such that the point of cach blade is on the
center line, or nearly so, of the axis of revolution, and so that the strain will be
received on the hub or nave at its greatest diameter, the whole construction of the
screw being on curved lines with no flat or angular surfaces or abutments against
which the sea can strike to impede its progress or break the blades and bend the
shaft on which they operate, all of which will herein-after more fully appear.
Referring to the accompanying Drawing, Figure 1 represents a perspective view
of my improved propeller; Fig, 2, a central sectional elevation of the same;
Figure 3, a form of blade differing from that of Figures 1 and 2. In Fig.
inner edges of the blades are slightly curved or made concave but not to such a
degree as to lessen their width.
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A represents the shaft upon which the screw is forced by hydraulic pressure or
other well known means. Conical bosses or collars C, C1, are forced against each
end of the nave, so as to form tight smooth joints and present rounding surfaces
from end to end. The blades D, D, are connected to the nave by short stout arms,
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page_text: which are also constructed so that no resistance is had by a counter nave or current
striking a resisting surface, but will pass around the throat of the arms harınless.
The blades D, D, are so bent or inclined as to act on the central line or axis of
revolution of the hub, and consequently the strain is transmitted to the hub at a
point best to resist, i.c., its greatest diameter, while the diameter of the two arms
are equivalent to three of the longest diameters of the hub.
If found necessary the blades may be set slightly from the vertical line of the
axis of revolution.
It will be seen that by this construction of screw propellers no sharp angles or
abutments appear, against which the wave may strike or friction be had in its 1
progress through the water, and that instead of angles, as in the ordinary con-
struction, nothing but curves are presented for the water to act upon.
Having thus fully described the nature of my said Invention, together with the
manner in which the same is to be performed, I claim,―
First. The blades of a screw propeller constructed of half discs, connected to the 1
nave by short stout arms and bent, substantially as described and shown.
Second. The combination with the shaft A and blades D of the nave and the
bosses C, C, when the said nave and bosses are constructed, so as to present
rounding surfaces from end to end, substantially as described and shown.
In witness whereof, I, the said Friedrick Henrich Bierent Babbe, have hereunto
set my hand and seal, this Sixth day of April, 1876.
FRIEDRICH HENKICH BIEKENT BABBL. (L.S.)