IMPROVEMENTS IN MEANS OR APPARATUS FOR REDUCING THE FRICTION NOW PRODUCED BY THE LONGITUDINAL OR ENDLONG PRESSURE OF SHIPS SCREW PROPELLER SHAFTS, OR OF ANY UPRIGHT OR INCLINED SHAFTS WHEN REVOLVING
Year: 1864

page_text: LETTERS PATENT to Martyn John Roberts, of Pendarren, near Crick-
howell, in the County of Brecknock, Esquire, for the Invention of
"IMPROVEMENTS IN MEANS OR APPARATUS FOR REDUCING THE FRICTION NOW
PRODUCED BY THE LONGITUDINAL OR ENDLONG PRESSURE OF SHIPS SCREW
PROPELLER SHAFTS, OR OF ANY UPRIGHT OR INCLINED SHAFTS WHEN
REVOLVING."
Sealed the 30th May 1865, and dated the 1st December 1864.
PROVISIONAL SPECIFICATION left by the said Martyn John Roberts at
the Office of the Commissioners of Patents, with his Petition, on the
1st December 1864.
I, MARTYN JOHN ROBERTS, of Pendarren, near Crickhowell, in the County
of Brecknock, Esquire, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN MEANS OR APPARATUS FOR REDUCING THE FRICTION NOW
PRODUCED BY THE LONGITUDINAL OR ENDLONG PRESSURE OF SHIPS SCREW PROPELLER
SHAFTS, OR OF ANY UPRIGHT OR INCLINED SHAFTS WHEN REVOLVING," to be as
follows:-
My improvements consist in placing that end of the screw propeller shaft or.
other shaft upon which friction is produced by the endlong or longitudinal
pressure of such shafts when revolving in a case or box containing water, oil,
or other liquid, and in such a position that the shaft end may be able to move
for a certain distance to or from the bottom of the case without touching that

page_text: bottom or passing out of the case. I make the mouth of this case or box
when the shaft end is within it as nearly water-tight as possible by means of
a stuffing box which embraces the shaft, and sometimes I use a double stuffing
box, that is to say, one stuffing box in front of the other, but with no aper-
ture between the two through which water can escape excepting through the
stuffing box itself. If needed, three or more such stuffing boxes may be used,
and to prevent the shaft from pressing injuriously upon the stuffing box I
support the shaft laterally or transversely by proper bearings. In order to
maintain the shaft in its proper position within the case containing water or
other liquid I connect the interior of the case with a pump, which is either
worked by the shaft itself or by some other mechanical power, and when the
liquid in the case is too small in quantity to support the shaft in its proper
position the shaft moves further into the case, and by this motion throws the
mechanism that actuates the pump into gear, and thus water or other liquid
is forced into the case, and the shaft returns to its proper place, and by this
return action throws the mechanism out of gear and the pump stops, or I
sometimes cause the pump to work continuously, and whenever the liquid
forced into the case exceeds the quantity necessary to maintain the shaft in its
proper position I cause the excess to escape either through a common safety
valve or through a valve which has its opening regulated by the position of
the shaft and this by the shaft itself, or I sometimes regulate the outflow of
the excess of liquid by making a groove or reduction of size in that part of
the shaft within the case and in such a position that when the shaft is pro-
truded too far out of the case the liquid is able to escape between this reduced
part of the shaft and the stuffing box, thus permitting the shaft to return to
its proper place, and I sometimes use a check or stop either at the end of the
shaft or at any part of its length in order to check any excessive motion of the
shaft endways; sometimes instead of supporting the shaft entirely by the
pressure of the liquid within the case I cause it to be supported partly by this
liquid and partly by a bearing either within or outside the case containing the
liquid, and I sometimes connect this case with a pipe or subsidiary reservoir
in which a piston or plunger slides for the purpose of throwing the pumping
apparatus into and out of gear by the pressure of the liquid within the pipe,
and also to afford egress to any excess of liquid that may be pumped into the
case containing the liquid, and if it be necessary to give elasticity to the pres-
sure within the case, I attach to it an air vessel or regulator somewhat in the
manner of that of fire engine pumps.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Martyn John Roberts in the Great Seal Patent Office on
the 1st June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTYN
JOHN ROBERTS, of Pendarren, near Crickhowell, in the County of Brecknock,
Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of December, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Martyn John Roberts, Her special licence that I, the said Martyn John
Roberts, my executors, administrators, and assigns, or such others as I, the
said Martyn John Roberts, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN MEANS OR APPARATUS FOR REDUCING THE FRICTION NOW PRODUCED BY THE
LONGITUDINAL OR ENDLONG PRESSURE OF SHIPS SCREW PROPELLER SHAFTS, OR OF
ANY UPRIGHT OR INCLINED SHAFTS WHEN REVOLVING," upon the condition
(amongst others) that I, the said Martyn John Roberts, iny executors or
administrators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and causo
the same to be filed in the Great Seal Patent Office within six calendar
months next, and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Martyn John Roberts, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fol-
lowing statement, reference being bad to the Drawings hereunto annexed,
that is to say-
My Invention consists in receiving the thrust or endlong pressure of pro-
peller and other shafts upon a fluid under continual pressure, whereby the
friction that would ensue between the end of such a shaft when revolving and
a solid support is in a great measure avoided. If an unelastic or nearly
unelastic medium such as water is used, I then prefer combining with the
apparatus whereby the fluid pressure is applied an air vessel whereby I obtain
an elasticity in the medium. Without such elasticity injurious jerks and

page_text: blows would be created in the shaft and between it and any solid bearings it
might come into contact with. Again, it is sometimes desirable that the shaft
should be as it were divided in its length so that the portion actually im-
pinging upon the fluid bearing should be independent of the main portion of
the shaft, to the end that should the main or principal portion of the shaft
sink in its bearings it should not cause that part of the shaft supported end-
long by the fluid medium to press severely on the sides of the box or cylinder
hereafter described which contains it.
My apparatus for effecting these ends consists of a cylindrical vessel open
at one end, into which the inner end of the shaft or the detached end which I
call the "plunger" is placed. I prefer to make this plunger hollow, for the
purpose not only of keeping it cool by the mass of fluid within it, but also that
when the shaft is not all in one piece the pressure of the water may be as
near the point of junction as is possible. This plunger fits the cylinder with
sufficient freedom to rotate, and sometimes has annular grooves round its sur-
face for the purpose of restraining or checking the flow or waste of the fluid
between the sides of the plunger and its containing cylinder. From this
cylinder a pipe leads to an air vessel, and from this to a pump of sufficient
size to force the water or other fluid into the cylinder at the desired pressure,
and also to keep up the supply and compensate for any waste of liquid between
the sides of the plunger and the cylinder. I also sometimes use a stuffing
box at the mouth of the cylinder still further to retard the waste of liquid.
The force pump being actuated by proper machinery is made to work con-
tinuously, and any excess of water the pump throws in beyond what runs
away
between the sides of the plunger and the cylinder or through the stuffing
box is permitted to escape through a proper valve weighted to the required
pressure, or the liquid may rise in a tube below a piston, and by this means
throw the force pump out of gear and stop it, but I prefer the constant action
of the pump,
and to permit the escape of a small portion of liquid between
the plunger and its cylinder whereby they are lubricated. I place a tap or
stop-cock between the air vessel and the cylinder for the purpose of shutting off
the pressure by closing the stop-cock when required, as, for instance, when
backing or going "astern."
The accompanying Drawing shews the manner in which I carry my Inven-
tion into effect. A is a screw propeller shaft; B the inboard end; C is a
plunger, which may be in a piece with or preferably in a separate piece from
the shaft; D is a cylinder or case in which the plunger is free to revolve
and play; I shew the plunger hollowed at back for the purpose herein-before
mentioned. a a are annular recesses in the outside of the plunger; E is a

page_text: pipe communicating with a force pump F, and also by the pipe b fitted with a
stop-cock c with an air vessel G.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim reducing the
friction produced by endlong pressure of screw propeller and upright or
inclined revolving shafts.
First, by the employment of fluid under continual pressure substantially
in manner herein-before described.
And, second, by the employment of liquid under continual pressure, to-
gether with an air vessel connected to the pipe, whereby such pressure is
conveyed, all substantially in manner and for the purpose herein-before
described.
In witness whereof, I, the said Martyn John Roberts, have hereunto set
my hand and seal, this Thirty-first day of May, One thousand eight
hundred and sixty-five.
MARTYN J. ROBERTS. (L.S.)