IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLERS
Year: 1876

page_text: LETTERS PATENT to Henry Samuel Eyre, of No. 9, Circus Road, Saint John's
Wood, in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF SCREW PROPELLERS."
Sealed the 12th May 1876, and dated the 14th March 1876.
PROVISIONAL SPECIFICATION left by the said Henry Samuel Eyre at the
Office of the Commissioners of Patents on the 14th March 1876.
HENRY SAMUEL EYRE, of No. 9, Circus Road, Saint John's Wood, in the County
of Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLERS."
This Invention relates to screw propellers in which the blades have combined
with them apparatus for altering their direction or pitch. For this purpose at the
root of each blado I form a tooth or teeth or a recess or recesses, at each side of
which I form a flat part or plane, and I arrange a rack or sliding plate in gear with
the root of each blade, so that by moving the said racks or sliding plates endwise
they shall turn the blade roots on their own axes, and when the blades have reached
their extreme position in either direction the flat or plane part of each blade root
will bear against a suitably formed part of its rack or sliding plate, whereby the
blade root will be as it were jammed up so as to lock the blade in the position to
which it has been moved. I connect the racks or sliding plates by a cross head or
plate, to which I give the necessary motion for simultaneously actuating the blades
by means of a shaft passing through a hollow part of the propeller shaft and
having a worm or screw formed around a part of its length, which worm or screw
takes into the cross head or plate; the screwed shaft is arranged to be rotated or
partially rotated, as required, for operating the cross head or plate and racks or
sliding plates, but to be incapable of end movement.
The above arrangement may be modified by attaching the inner shaft firmly to
the cross head or plate and arranging said shaft to be moved endwise by means of a
sleeve arranged upon the propeller shaft, and formed with worm-shaped slots or
grooves which receive the ends of a cotter fixed to the inner shaft, the said ends
passing through longitudinal slots in the propeller shaft.
My improved method of locking the blades inay be applied to propellers differing
in construction from those above described or referred to. The number of blades in
a single propeller will depend upon circunstances.
The blade roots may be arranged with their teeth or recesses and their actuating
racks or sliding plates at or nearly at the opposite sides of the roots to the flat
77

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Henry Samuel Eyre in the Great Seal Patent Office on the 9th August
1876.
HENRY SAMUEL EYRE, of No. 9, Circus Road, Saint John's Wood, in the County
of Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION OF SCREW PROPELLERS."
This Invention relates to screw propellers in which the blades have combined
with them apparatus for feathering or altering their direction or pitch. For this
purpose at the root of each blade I form a tooth or teeth or a recess or recesses, at
each side of which I form a flat part or plane, and I arrange a rack or sliding plate
in gear with the root of each blade, so that by moving the said racks or sliding
plates endwise they shall turn the blade roots on their own axes, and when
the blades have reached their extreme position in either direction the flat or plane
part of each blade root will bear against a suitably formed part of its rack or
sliding plate, whereby the blade root will be as it were jammed up so as to lock the
blade in the position to which it has been moved. I connect the racks or sliding
plates by a cross head or plate, to which I give the necessary motion for simultaneously
actuating the blades by means of a shaft passing through a hollow part of the
propeller shaft and having a worm or screw formed around a part of its length,
which worm or screw takes into the cross head or plate. The screwed shaft is
arranged to be rotated, as required, for operating the cross head or plate and racks
or sliding plates, but to be incapable of end movement.
My improved method of locking the blades may be applied to propellers differing
in construction from those above described or referred to. The number of blades in
a single propeller will depend upon circumstances.
The blade roots may be arranged with their teeth or recesses and their actuating
racks or sliding plates at or nearly at the opposite sides of the roots to the flat
parts, whereby the locking is effected, and separate locking plates or wedge pieces
operated from the same cross head or plate may be used for effecting the locking.
Fig. 1 is a longitudinal vertical section (taken in the line A, B, of Fig. 3) shewing
part of a screw propeller constructed according to my Invention; Fig. 2 is a sectional
plan of the same taken in the line C, D, of Fig. 3; Fig. 3 is a transverse vertical
section taken in the line E, F, of Fig. 1.
a, a, a, are the blades; b, b, b, their roots, each having formed therein a recess c,
at each side of which there is a flat part or plane d; e are racks or sliding plates,
one in gear with each blado root; fis a cross head or plate connected to each of
the racks or sliding pieces e by nuts, as shewn; g is the shaft for giving the necessary
motion to the racks and cross head for simultaneously altering the blades. This
shaft passes through the hollow part of the propeller shaft h, and has formed upon a
portion of its length a worm or screw i passing through a correspondingly screwed
hole in the cross head or plate f, so that when the shaft g is turned its screw will
cause the cross head and the racks to be moved backward or forward, according to
the direction in which the shaft is turned; ; is a disc or solid wheel formed on the
inner end of the shaft g; this disc or solid weeel, which prevents any end movement
of the said shaft has holes formed in its periphery to receive the end of a bar or
other instrument for turning the disc or wheel and with it the shaft g.
Having thus described the nature of my said Invention, and explained the
manner of carrying the same into practical effect, I desire to have it understood
that I do not intend to claim per se the use of racks in gear with the roots of
propeller blades for feathering or altering their direction or pitch, but what I
consider to be novel and original, and therefore claim as the Invention secured to
me by the heroin-before in part recited Letters Patent is, the method substantially

page_text: as herein described of locking the blades in the positions to which they have been
moved by causing a flat or plane part of each blade root to bear against a corres-
pondingly formed part of its rack on the termination of the movement of the latter,
as herein set forth.
In witness whereof, I, the said Henry Samuel Eyre, have hereunto set my
hand and seal, this Eighth day of August, in the year of our Lord One
thousand eight hundred and seventy-six.
H. S. EYRE. (LS)