Improvements in Reversible Screw Propellers.
Year: 1892

page_text: Date of Application, 5th Feb., 1892-Accepted, 2nd Apr., 1892 -
COMPLETE SPECIFICATION.
Improvements in Reversible Screw Propellers.
I, MAX WEIHE retired Captain Lieutenant of the German Navy residing at
No. 10 Alsterdamm Hamburg in the Empire of Germany 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 screw propellers for ships or smaller vessels in which the
blades are movable so that the direction in which the vessel is moving may be
reversed without reversing the engines, and the object of the improvements is to
render the connection between the blades and the central boss of the propeller
stronger and to provide for the convenient removal or insertion of any of the
blades.
The accompanying drawing illustrates the improved propeller―
Fig. 1 being a vertical longitudinal section of a two bladed propeller-Fig. 2 a
horizontal section thereof-Fig. 3 a vertical cross section thereof.
Fig. 4 is a vertical cross section of a three bladed propeller.
Figs. 5 and 6 are detail views of the mechanism for moving the blades for reversing
the propeller.
Fig. 7 is a longitudinal vertical section of a modified construction of propeller.
Fig. 8 is a horizontal section and Fig. 9 is a vertical cross section thereof.
Fig. 10 is a horizontal section of a further modified construction of propeller.
A is the hollow boss of the propeller B is the propeller shaft. C the revolvable
blades. D is a rod moveable endwise within the shaft B and having in its forked
end g the teeth which gear with the teeth a', on the inner ends of the shanks of
the propeller blades respectively.
2
The shanks m of the propeller blades are not made cylindrical but in the form of
two cones placed base to base partly to obtain a water tight joint and partly to
enable them to be secured in the boss A by the screw threaded rings rr which are
made each in two halves. The racks are arranged one on each arm of the fork g
and in different planes, the rack on the one arm gearing with the teeth z¹ on the
shank of the one blade and the rack on the other arm gearing with the teeth ¹ on
the shank of the other blade, and the teeth are so engaged that when the fork g is
drawn back as in Fig. 2 the one blade occupies the position a while the other
occupies the position y. y. On thrusting forward the fork g (i.e. outward aft of the
ship) the blades are revolved in opposite directions and that previous at x, x passes
into the plane y. y while that previous at y y passes into the plane xx.
For propellers with more than two blades the construction of the fork 9 is altered
correspondingly as in Fig. 4.
In the construction shown in Figs. 5 and 6 the rod D is provided at its inner end
with a cross pin i passing through slots e e in a box forming part of the shaft B and
engaging in an annular recess in a ring w which may be moved by a lever h pivoted
at t so as to adjust the rod D without interfering with its rotation.
By turning the blades C more or less within their extreme positions the vessel
may be caused to travel faster or slower if the velocity of the engines is controlled
by suitable governors.
In the modification shown in Figs. 7 to 9 the teeth 2' are replaced by a single
gudgeon z on the trunnion m of each blade C, and in place of the fork g with its
teeth, a block or enlargement d on the rod D is employed and provided with a cross
slot d¹ to receive each gudgeon z. The gudgeons being excentrically placed on the
trunnions m, the end wise movement of the rod D causes the blades to revolve on lines
radial to the boss A through about 90°. For a three bladed propeller the block d
is made with three slots d¹.

page_text: Fig. 7 shows also a modification in the method of fastening the blades to the boss;
in place of a double conical trunnion m the latter is made conical at the end but
above the conical end it is recessed cylindrically to receive the collar r. The collar r
is also here shown as secured by screw bolts p instead of by being threaded to screw
into the boss A. The collar ris in two parts as aforesaid.
A further modification is shown in Fig. 10, the gudgeon in place of being
engaged in a slot in a block d, is connected to the rod D by a short connecting link,
there being a link for each blade.
I do not claim broadly a propeller with moveable, adjustable, or feathering
blades, but,
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.) A screw propeller having adjustable or feathering blades C, with teeth on
the trunnions thereof in combination with the endwise moveable rod D with
fork or equivalent y and teeth ¹ thereon substantially as and for the purpose set
forth.
2.) A screw propeller in which the trunnions of the blades are revolvably secured
in the boss by collars in two parts, the said trunnions being of double conical
form, or made with conical ends and cylindrically recessed above said ends sub-
stantially as described and illustrated.
3.) A screw propeller in which the trunnions of the blades are provided each with
an excentrically placed gudgeon z in combination with a rod D with block d having
slots d¹ for engagement of said gudgeons respectively, substantially as and for the
purpose set forth.
4.) A screw propeller in which the trunnions of the blades are provided each with
an excentrically placed gudgeon in combination with a rod D and a connecting
link for each gudgeon substantially as and for the purpose set forth.
Dated this 5th day of February 1892.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.