AN IMPROVED SCREW HELM FOR STEAMERS
Year: 1880

page_text: LETTERS PATENT to Comte Charles de Bruc, Duc de Busignano, of Boulevard
Saint Denis, 1, at Paris, for an Invention of "AN IMPROVED SCREW HELM
FOR STEAMERS."
PROVISIONAL SPECIFICATION left by the said Comte Charles de Bruc at
the Office of the Commissioners of Patents on the 8th July 1880.
Comte CHARLES DE BRUC, Duc de BUSIGNANO, of Boulevard Saint-Denis, 1, at
Paris. "AN IMPROVED SCREW HELM FOR STEAMERS."
My Invention relates to an improved screw helm for steamers, and is characterized
by the great facility, security, and rapidity with which it can be worked; it will
allow the ship to turn in a very small radius. By the use of this system or
arrangement of screw helm the rudder surfaco need not be taken into consideration
and only its solidity need be considered. The special arrangement of gearing,
hereinafter described, permits of the instantaneous action of the screw for turning
the vessel, no matter in what position the rudder may be.
My system or arrangement may be applied in two ways, either by using an
auxilary steering screw or by fitting the main propelling screw to serve as a steering
screw.
When an auxiliary scrow is used it is mounted on an independent shaft revolving
in the rudder, and the rotation of the main shaft is transmitted to the auxiliary
propeller, whatover be its position, by suitable bevil gearing. The first pinion of
this gearing is connected with the auxiliary propeller, and the second is mounted
on the end of the main shaft. The main shaft carries a hollow shaft upon which
the main screw propeller is keyed. A sleeve or clutch allows this propeller to be
thrown into gear at will.
The auxiliary screw can be brought into or thrown out of gear by means of an
intermediate pinion mounted loose upon the rudder post; this intermediate pinion
can be raised by means of suitable lifting gear, and it being thereby thrown out of
gear the auxiliary screw propeller disconnected.
For this purpose the rudder-post is hollow, and contains a rod, which has on its
lower end a clutch formed in two pieces bolted together; this clutch is attached to

page_text: the rod by means of a key or pin. A re-entering flange, turned on the inside of
the clutch, enters a collar cut on the bush of the intermediate pinion and serves to
raise the said pinion.
Two small mortices cut in the hollow post allow free play to the key or pin.
The upper end of the clutch rod is threaded and a nut provided with a handle
and held by two plates takes into the neck or collar of the said rod, and thus such
rod, together with the intermediato pinion, can be brought into or thrown out of
gear with the greatest facility.
The change of inclination of the rudder, even to the extent of 90°, can easily be
produced by means of a pinion fitted with a hand-wheel and a toothed wheel keyed
on to the hollow shaft carrying the rudder.
The working of the auxiliary screw will therefore be constantly effected by the
-bevilgearing and-under-the-same conditions. The intermediate_pinion_has a
diameter larger by about d than that of the other two pinions, so that these latter
may not come into contact and their teeth broken when the rudder is brought hard
to one side, that is to say, to 90°.
The second arrangement differs from the preceding one by the suppression of the
auxiliary screw and its replacement by the main propelling screw. Tho
arrangement for throwing the intermediate pinion out of gear becomes unnecessary
as well as the contrivance of a hollow main shaft and its clutch for throwing it into
gear.
The main propelling screw will in this case fulfil both the purposes of a
propelling screw and of a steering screw. It is a propelling screw when the two
driving shafts are quite or almost in a straight line, and a steering screw only when
-the-shafts-stand-at-an-angle-;-this will-permit-the-rapid turning of the ship_by_the_
simple action of the hand-wheel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Comte Charles de Bruc in the Great Seal Patent Office on the
4th January 1881.
Comte CHARLES DE BRUC, Duc de BUSIGNANO, of Boulevard Saint Denis, 1, at
Paris. "AN IMPROVED SCREW HELM FOR STEAMERS."
My Invention relates to an improved screw helm for steamers, and is characterized
by the great facility, security, and rapidity with which it can be worked; it will
also allow of the vessel being turned in a very small radius. By the use of this
system or arrangement of screw-holm the rudder surface need not be taken into
consideration, its solidity alone being considered. The special arrangement of
gearing, hereinafter described, permits of the scrow acting instantaneously to turn
the vessel, no matter what may be the position of the rudder..
My system or arrangement may be applied in two ways: first, by using an
auxiliary steering scrow; and secondly, by so contriving the main propelling screw
as to cause it to serve as a steering scrow.
In the annexed Drawings Fig. 1 is a longitudinal section of the stern post of a
steam ship with the mechanical arrangements necessary for carrying my first
arrangement into effect.
Fig. 2 is also a longitudinal section of the stern post of a ship, showing another
arrangement or modification of my Invention.
When an auxiliary screw h (Fig. 1) is to be used it is mounted on an independent
shaft a', which revolves in the rudder g. The rotation of the main shaft a is
transmitted to the screw in all its positions by the bevil gearing b, b', and 6", tho
first pinion of which is mounted fast on the shaft a¹ of the said auxiliary screw h,
and the second b on the end of the shaft a, which carries the hollow shaft a", ou
which the screw propeller H is keyed; m is a clutch which allows the scrow
propeller H to be brought into gear at will.
The auxiliary steering screw can also be brought into or thrown out of gear by
means of the third or intermediate pinion 6, which is mounted loose on the
rudder post c; this intermediate pinion 6" can be raised by means of suitable gear,
hereinafter described, and when raised the auxiliary screw propeller detached.
For this purpose the rudder poste is made hollow, as seen at c¹, Fig. 1, and
contains a shaft t, which carries at its lower end a connecting clutch n, formed in
two pieces bolted together; this clutch is secured to the shaft t by means of a key
pin or cotter d. A re-entering flange on the inside of the clutch enters a collar
cut on the bush of the pinion and serves to raise this pinion. Two small
mortices cut in the hollow rudder post c' allow free play to the key, pin, or cotter d.
The shaft t is screw-threaded at its upper end and is provided with a nut furnished
with a handle held between two plates p engaging in a collar on the nut; this
shaft and the pinion 6" are caused to rise and fall at will and the pinion brought
into or thrown out of gear with the greatest ease.
The change of inclination of the rudder and of its screw can be easily effected,
even to an angle of 90°, by means of the pinion, which is worked by the hand
wheel บ, and by the toothed wheel y' keyed on the hollow rudder post c¹.
The working of the auxiliary screw propeller will thus be effected in the samo
manner by the bovil gearing b, b, The intermediate pinion 6" is of larger
diameter by about than are the pinions and b¹ in order that these latter may
not be injured and their teeth broken on the rudder being brought hard to one
side, that is to say, to an angle of 90°.
The second arrangement, shown in Fig. 2, differs from the preceding by the
auxiliary screw propeller being dispensed with and the propeller H being employed
in its stead. Therefore the mechanism for throwing the intermediate pinion 6"
out of gear, the hollow rudder post and its clutch, are not here necessary.

page_text: In this arrangement the screw H answers the double purpose of screw and of
rudder, or, in other words, propelling screw and steering screw, it being a
propelling screw when the driving shafts are in a straight line or nearly so with
each other and a rudder or steering screw only when the shafts are at an angle to
each other, thus allowing of the vessel to be rapidly turned by the simple action of
the handwheel v.
This system of screw helm is applicable to steam vessels of all sizes and
tonnage.
Having now described the nature of my said Invention, and in what manner the
same may be performed, I declare that I claim,—
First. Mounting the auxiliary screw propeller in the rudder substantially as
specified, and operating the-said-propeller_by_means of the_special_arrangement_of
gearing herein described and shewn.
Second. The optional mounting of the screw propeller on the hollow rudder
post without the use of any special mechanism for throwing it out of gear, as
described and shown.
In witness whereof, I, the said Charles de Bruc, have hereunto set my hand
and seal, this Thirteenth day of December, in the year of our Lord One
thousand eight hundred and eighty.
Witness,
THE CHARLES DE DRUG, DOC DE DUMIRAG
ALBERT CAHEN,
Civil Engineer,
of Boulevard Saint Denis, 1, at Paris.