IMPROVEMENTS IN STEERING GEAR
Year: 1884

page_text: I THOMAS ARCHER junior of Dunston Engine Works, Dunston in the Parish
of Gateshead, Engineer do hereby declare the nature of my invention for
IMPROVEMENTS IN STEERING GEAR, to be as follows:-
My Invention of improvements in steering gear consists of a simple arrangement
whereby steam may be caused automatically to assist in the movement of the
rudder of a ship. The arrangement is susceptible to various modifications, but its
essential principle consists in the use of a steering wheel which is not keyed to its
shaft and free to move a given distance backward and forward upon the same.
The boss of the steering wheel, or the prolongation of it, is fitted with a slot or
groove at an angle in relation to the shaft with a pin fixed to the shaft working in
the slot. The boss of the steering wheel is further provided with an arrangement
by which a lever or rod can be attached to it; the other end of which rod is in
connection with the valve or slide admitting steam into the cylinder or cylinders.
Instead of the slot or groove in the boss of the steering wheel, various other
arrangements can be made, all resting upon the same principle and having the same
effect, as for instance the steering shaft may be provided with a screw and the boss
of the steering wheel fitted with a corresponding nut working loosely upon it. In
order to ensure the steering wheel when left free always returning to its middle
position upon the shaft, in which position the admission of steam to the auxiliary
engine is shut off, I apply one or more springs or weights to any convenient part
of the mechanism and in such a way as to tend adequately to this effect. These
springs or counterweights have a second action namely if the movement of the
rudder be very easy they tend to restrict or altogether to prevent the admission of
steam to the auxiliary engine by locking the wheel to the extent of the influence
of their tension or weight.
The working of the gear is as follows: When the steering wheel is in its middle
position steam is shut off from the cylinders and the gear is at rest. By turning
the wheel in one direction the slot in the boss slides upon the pin in the shaft, the
steering wheel is carried a certain distance forward upon the shaft, the lever attached
to its boss moves also forward and the other end of it lifts the valve spindle and so
admits steam to the auxiliary engine or steam cylinder in one direction. By
turning the steering wheel in the other direction, the reverse result is obtained and
Duien B1

page_text: steam is admitted to the opposite side of the auxiliary engine or steam cylinder.
The spring or weight arrangement always tends to bring the steering wheel back
to its middle position when left free and steam is thereby automatically shut off.
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 :-
The use of a steering wheel free to revolve upon its shaft within such limits as
that before it reaches the full limit of its rotary movement on the shaft in either
direction, steam shall be admitted to operate the rudder in the direction of the
movement of the wheel, substantially as described.

page_text: THOMAS ARCHER, junior, of Dunston Engine Works, Dunston, in the parish
of Gateshead, Engineer, do hereby declare the nature of my invention for
IMPROVEMENTS IN STEERING GEAR, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention of improvements in Steering Gear consists of a simple arrangement
whereby steam may be caused automatically to assist in the movement of the
rudder of a ship. The arrangement is susceptible of various modifications, but its
essential principle consists in the use of a steering wheel which is not keyed to its
shaft and free to move a given distance backwards and forwards upon the same.
The boss of the steering wheel, or the prolongation of it, is fitted with a slot or
groove at an angle in relation to the shaft with a pin fixed to the shaft working in
the slot. The boss of the steering wheel is further provided with an arrangement
by which a lever or rod can be attached to it the other end of which rod is in
connection with the valve or slide admitting steam into the cylinder or cylinders.
Instead of the slot or groove in the boss of the steering wheel, various other
arrangements can be made, all resting upon the same principle, and having the
same effect as for instance the steering shaft may be provided with a screw and the
boss of the steering wheel fitted with a corresponding nut working loosely upon it.
In order to ensure the steering wheel, when left free, always returning to its middle
position upon the shaft, in which position the admission of steam to the auxilliary
engine is shut off. I apply one or more springs or weights to any convenient part
of the mechanism and in such a way as to tend adequately to this effect. These
springs or counterweights have a second action namely if the movement of the
rudder be very easy they tend to restrict, or altogether to prevent the admission of
steam to the auxilliary engine by locking the wheel to the extent of the influence
of their tension or weight. The working of the gear is as follows:-
When the steering wheel is in its middle position steam is shut off from the
cylinders and the gear is at rest. By turning the wheel in one direction, the slot.
in the boss slides upon the pin in the shaft the steering wheel is carried a certain
distance forward upon the shaft the lever attached to its boss moves also forward
and the other end of it lifts the valve spindle, and so admits steam to the auxilliary
engine, or steam cylinder in one direction. By turning the steering wheel in the
other direction the reverse result is obtained, and steam is admitted to the opposite.
side of the auxilliary engine or steam cylinder. The spring or weight arrangement
always tends to bring the steering wheel back to its middle position when left free,
and steam is thereby automatically shut off.
In the drawing similar letters are used to represent similar parts of the machine.
Figs 1 and 2 are vertical elevations of the machine and Fig. 3 a plan. a, is the
steering wheel which is mounted on a spindle b, so that it can revolve to a limited
extent without the revolution of the spindle or conversely so that the spindle may
revolve to a limited extent without the revolution of the wheel, there is however
contained in the boss of the wheel a spiral recess and on the spindle is a projection
fitting into it as is well understood, or the spindle may be formed into a coarse
pitched screw and the boss of the wheel into a nut, whereby when either the wheel
or spindle revolves without the other, the position of the wheel on the spindle is
not only changed in the direction of the axis of the spindle but also longitudinally
the amount of such longitudinal change depending upon the amount of axial
movement and the pitch of the spiral recess. c, is a lever at the top end of which
there is a pin fitting into a recess on the boss of the wheel so that any longitudinal

page_text: movement of the wheel and boss shall through this pin cause a movement of the
lever c, the lever c turns on the centre d, and through an adjustable connecting link
works the bell-crank e, and the slide rod f. This rod is attached to a piston valve
or other convenient form of valve contained in the steam chest g, and the movement
of this valve gives steam either above or below a piston in the steam cylinder h.
The movement of the piston of the cylinder h, moves the rack i, and a corresponding
toothed wheel j, on the shaft b, so as to act in the same direction as the pull upon
the steering wheel. There is a clutch arrangement of an ordinary form shewn atk,
so as to release the wheel j, when steam steering is not required. l, is the chain
wheel and I have shewn the multiplication of power by means of my patented
steering arrangement N° 512, 2nd February 1882, but of course this may be replaced
by a worm wheel and worm or any convenient form of self holding apparatus.
On the spindle of the slide valve f, are two strong spiral springs one of which is
compressed and the other of which is elongated by any movement of the slide rod.
If these springs were absolutely rigid no longitudinal movement of the steering
wheel could take place excepting what might be due to looseness of fitting but by
their elasticity a certain amount of movement becomes possible and of course the
slide is moved as the springs yield. The strength of spring tends to keep the
steering wheel in a central position as regards its. longitudinal movement, and
the slide being set to cut off steam at both ends of the steam cylinder, when in
this position there must be longitudinal movement of the wheel on the spindle b,
before steam can be applied. Thus on pressure being applied to revolve the
steering wheel in either direction, there will be produced longitudinal movement
dependent upon the relation of the resistance given by the helm and its intermedial
gear and the resistance given by the spring against which the movement exerts
pressure and thus against adequate resistance steam is applied and against slight
resistance no steam is applied or very little. When however the steam operates
upon the spindle b, and (as it might do if the whole arrangement were fixed) the
revolution of the spindle b, tends to overrun the wheel, the action of the spiral
slot and pin in the boss of the wheel before described, causes the whole to move
longitudinally in the opposite direction to its first impulse and the steam is shut off
or even reversed. I have shewn the springs for convenience on the slide spindle
but they may be arranged so as to have the same effect upon the spindle b, or
elsewhere or they may be replaced by weights or other convenient arrangement of
resistance. I may also use a steam engine of ordinary form with the spring
arrangement and valve to give steam in a forward or backward direction as is well
understood, but I prefer for simplicity and efficiency the arrangement shewn in the
drawing, which arrangement I believe to be the best.
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
In combination with selfholding arrangement for the valve, the use of a steering
wheel free to revolve upon its shaft within such limits and under such control of
springs, weights or resisting arrangements substantially as described, as that
proportional or nearly so to the resistance to be overcome in the helm and its gear,
steam shall be supplied so as to operate the rudder in the direction indicated by
and approximately in proportion to the power applied to the wheel.