Year: 1885

page_text: I, ALFRED HEAD ALCHIN, of 89 Wood Lane, Shepherds Bush, London, in the
County of Middlesex, Engineer, do hereby declare the nature of this invention to
be as follows:-
°
The object of my invention is to effect an equable movement of a ship's rudder
in any weather, without allowing the "kick" which is so detrimental and
destructive to the chains, rods and other gear connected with the controlling of
the rudder in the usual way.
For this purpose I employ a cylinder or cylinders attached to the ship or vessel,
and each containing a piston the rod of which is connected to the tiller or quadrant,
as may be most convenient. The cylinder is closed at both ends, the piston rod
passing through a stuffing box or gland provided at one end, and the space in the
cylinder, on both sides of the piston, is filled with a suitable fluid, such as oil. As
the tiller is moved the piston is caused to travel in the cylinder, and provision is
made to enable the fluid in the latter to pass freely from one side of the piston to
the other.
For this purpose passages may be formed through the piston, or the opposite
ends of the cylinder may be connected by a pipe or passage; or if desired these
two methods of allowing the fluid to pass from one side of the piston to the other
may be combined. The pipe or passage connecting the opposite ends of the
cylinder may be provided with a cock so as to regulate the flow of the liquid
therethrough.
In order to take up the "kick" and so relieve the steering gear from sudden
strains, the passages through which the fluid passes are capable of being auto-
matically closed to a greater or less extent immediately upon any tendency of a
sudden movement of the piston in the cylinder. In the case of the passages
through the piston this can be effected either by making the piston itself capable
of sliding in both directions on its rod for a limited distance, against the action of
suitable springs, and providing fixed abutments on the rod, so that when the
piston comes in contact there with the passages will be entirely closed; or each
passage in the piston may be provided with a valve at each end, kept open by a
suitable spring, but capable of closing against the action of such spring should the
piston have a sudden tendency to move too quickly in the cylinder.

page_text: In the case of the passage or pipe connecting the two ends of the cylinder being
employed, the same result may be effected by fitting each end of such passage with
a valve kept open by a spring as above described in relation to the passages
through the piston.
The cylinder is attached to the vessel by a pivoted connection, or other suitable
means are adopted to enable the cylinder and piston rod to adapt themselves to the
movement of the tiller or quadrant.
I, ALFRED HEAD ALCHIN, of 89, Wood Lane, Shepherds Bush, London, in the
county of Middlesex, Engineer, do hereby declare the nature of my said Invention,
and in what manner the same is to be performed, to be particularly described in
and by the following statement :-
This Invention relates to an improved buffer or means of controlling the
movements of ships' rudders, and consists of an automatio self-contained buffer of
the novel construction hereinafter described, the especial object of the Invention
being to provide such an appliance of a simple and inexpensive construction.
On the accompanying drawings Figure 1, represents a longitudinal section of the
principal working parts of the buffer, illustrating the improved construction and
arrangement thereof:-Figure 2, represents a transverse section through a. b.
Figure 1. Figures 3, and 4. represent respectively a plan view and an elevation
illustrating a suitable method (not however in any way material to the present
improvements) of applying the improved buffer to the quadrant of a ships' rudder.
The improved rudder-buffer is constructed with a cylinder, 1, adapted with a
stuffing-box, 2, at each end, the stuffing-boxes permitting of and guiding the
reciprocating movements of a projecting piston-rod, 3; which extends through the
cylinder, and is made of the same diameter throughout all parts working within
the cylinder, so that the different positions it assumes do not cause any variation
in the internal capacity of the cylinder, and I thus dispense with the necessity of
means for compensating any such variation.
Within the cylinder, the piston rod is adapted with two nuts or abutments, 4,
which can be set at any required distance apart and caused to occupy such relative
positions by set pins, 5, or other convenient means.
The piston-rod at a part between the nuts, 4, is adapted with freely fitting
oppositely disposed piston-rings, 6, of a tubular formation, 7, at the parts which

page_text: fit about the rod, and of a flanged formation at the parts, 8, which are adapted to
work against the interior surface of the cylinder, the flanged extensions, 8, being
also recessed, as at, 9, for the purpose of receiving a helical steel or other spring, 10,
the normal tendency of which is to keep the piston-rings apart and abutting against
the nuts, 4.
The opposing faces of the piston-rings are each formed with a series of through
apertures, 11, of a conical or other suitable shape, and which are so disposed as that
the apertures of the one piston-ring are opposite the intervening blanks, 12, of the
other piston-ring. Both of the piston-rings are adapted to receive independent
endwise movements along the piston-rod from or towards each other and within
the limits afforded by the nuts, 4, the through apertures, 11, of each piston-ring
being kept opposite the intervening blanks, 12, of the other piston-ring by a
key, 13, carried by the one piston-ring engaging in a groove, 14, formed in the
opposite piston-ring, or by other suitable means.
The cylinder, when containing such parts properly adjusted, is filled with oil or
other suitable fluid, and is closed, and the improved rudder-buffer is then in
operative condition, and is self-contained and independent of any external fittings
excepting such as may be necessary to connect its acting end with the quadrant,
circle or tiller of a ship's rudder. In the modification for effecting this which is
represented on the accompanying drawings, (but which, however, as hereinbefore
stated, is in no way material to the present improvements,) one end or part of the
cylinder is pivotted to a bifurcated arm, 15, in such a manner as to have facility of
turning movements about such pivots in a vertical plane, and such arm can freely
turn in a support, 16, bolted or otherwise attached to the deck or other convenient
part of the ship or vessel, in such a manner as to allow of the cylinder also having
facility of movement in a horizontal plane, the connection, 15, 16, practically
constituting a universal joint permitting of all required movements of the
cylinder, 1.
Beyond dispensing with the necessity of providing for compensation for
variation of the internal capacity of the cylinder, as aforesaid, the improved
construction also dispenses with the need of any internal valves, which are so
liable to get out of order in apparatus of such kind and to render such apparatus
useless.
Upon the tiller, quadrant or circle being actuated in the usual way to cause the
required movement of the rudder, the piston-rod is caused to travel in the cylinder,
carrying the piston-rings with it, the intervening spring keeping them more or less
apart as they travel through the contained oil in accordance with the speed of the
motion of the rod in the cylinder, and permitting of the oil passing through the
said apertures in accordance with such distance apart, the resistance to the end wise
movement of the rod increasing in proportion to the suddenness or quickness
thereof, so that immediately any sudden strain comes upon the rudder, whether
caused by a heavy sea or otherwise, the tendency is to cause the piston to more
rapidly move in the cylinder and to compress the oil, more quickly than it can
pass, through the piston-rings, and thus the compressing ring is caused to overcome
the distending resistance offered by the spring, 10, and to more nearly approach
the other piston-ring and to close or nearly close the said through apertures, 11,
which consequently prevents the rapid traverse of the piston-rod, and obviates the
"kick" which would otherwise be given to the steering gear, and which is so
destructive to the chains, rods and other gear connected with the controlling of
the rudder in the usual way, and relieves the same from sudden strain causing an
equable movement of the ship's rudder in any weather.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. An improved automatic self-contained buffer for controlling the movements
of ships' rudders; consisting of a cylinder containing oil or other suitable fluid and

page_text: provided with end stuffing boxes fitting a through piston-rod of equal diameter
throughout its working part, such rod being adapted with adjustable abutments
and with oppositely disposed piston-rings having independent guided movements
longitudinally of the rod within the limits afforded by such abutments, and such
rings being formed with through apertures and intervening blanks arranged
relatively to each other in the manner herein before described, and being normally
kept apart by a helical or other spring; when such parts are so arranged and
combined as to act for the purposes of the Invention substantially in the manner
herein before described.
2. The herein before described improved construction of piston applicable for the
purpose of the Invention, the same consisting of the rod, 3; adapted with adjustable
abutments, 4, in combination with the oppositely disposed piston-rings having
independent guided movements, longitudinally of the piston-rod within the limits
afforded by such abutments, and formed with through apertures and intervening
blanks arranged relatively to each other in the manner herein before described, and
with a helical or other spring for normally keeping such rings apart, substantially
in the manner herein before described.
DAY, DAVIES & HUNT,
Agents for the Applicant.