AN IMPROVED APParatus FOR FORCING SCREW PROPELLERS OFF THEIR SHAFTS, AND FOR OTHER SIMILAR PURPOSES
Year: 1875

page_text: LETTERS PATENT to Thomas Fenwick Reed, of Jarrow, in the County
of Durham, Engineer, for the Invention of "AN IMPROVED APParatus
FOR FORCING SCREW PROPELLERS OFF THEIR SHAFTS, AND FOR OTHER SIMILAR
PURPOSES."
Sealed the 14th September 1875, and dated the 25th March 1875.

page_text: having a sliding piece in two of its opposite sides actuated by the oval
portion of a shaft working within the box, between the stern post of the
vessel and the screw propeller, then by giving a quarter turn to the
lever handle fitted to the upper part of the shaft or spindle extending
beyond the box the long diameter of the oval portion is brought towards
the two slides, driving them outward from the centre, thus forcing the
screw propeller from its bed and rendering it easy of removal.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Fenwick Reed in the Great Seal Patent
Office on the 25th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
FENWICK REED, of Jarrow, in the County of Durham, Engineer, send
grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of March, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did for Herself, Her heirs and successors, give
and grant unto me, the said Thomas Fenwick Reed, Her special licence
that I, the said Thomas Fenwick Reed, my executors, administrators,
and assigns, or such others as I, the said Thomas Fenwick Reed, 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 "AN IMPROVED
APPARATUS FOR FORCING SCREW PROPELLERS OFF THEIR SHAFTS, AND FOR OTHER
SIMILAR PURPOSES," upon the condition (amongst others) that I, the said
Thomas Fenwick Reed, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and cause
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.

page_text: NOW KNOW YE, that I, the said Thomas Fenwick Reed, 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 following statement in writing, reference being had to the
Drawing hereunto annexed, and to the letters and figures marked
thereon (that is to say):-
The object of this Invention is to provide for engineers a compact and
handy tool or apparatus to enable them readily to remove a screw
propeller from its shaft. Hitherto this has been performed by the
tedious method of driving wedges between the boss of the propeller and
the stern post of the vessel, or by the more dangerous means of gun-
powder, to both of which there are great inconveniences, loss of time,
and in some instances damage done.
To obviate the dangers and defects of the present system I have
Invented a new tool or apparatus, which I call a propeller jack, to meet
the requirements of the engineer.
On the accompanying Drawing I have shewn various views of my
Invention, and the manner of applying the same to various useful
purposes.
Figure 1 is a sectional clevation of the apparatus; Figure 2, an end
view; Figure 3, a sectional plan on the line A, B, in Figure 1; and
Figure 4, a plan.
In Figures 8 and 9 are shewn a modified form of the apparatus.
the
In all these Figures a is the body of the tool or box in which turns
the short shaft b. This shaft is of various shapes in cross section ;
first or upper part is heptagonal to receive the lever handle E, Figures 5
and 6, the second round, to work in a bearing in the upper face or
surface of the body of the tool; the third portion is of an elliptic form,
the transverse diameter of which does exceed the diameter of the
circular part above, while the conjugate or smaller diameter of the
ellipse is so arranged that the steel slides c, c, shall come flush with
the end of the box a when the propeller jack is prepared for use, conse-
quently when the shaft is made to turn in the direction of the arrows
shewn on Figure 4 the increasing diameter of the elliptical portion of
the shaft bears upon and thrusts out the two steel slides c, c, as shown
by dotted lines, Figures 1 and 3. The slides are prevented by a small

page_text: pin & running in a groove from falling outward and being lost in the
water, mud, or rubbish when the apparatus has performed its work, and
for further security and convenience of handling the ring x, to which a
a rope may be fastened, is screwed into the box. The shaft 6 is kept in
position by two set screws e, e, there being a groove f cut round the
lower end of the shaft, which is circular, to receive the ends of them,
and the whole of the bearing surfaces lubricated by means of the oil
cups 1, 1.
In Figure 10 (drawn to a reduced scale) I have shown the application
of the propeller jack in forcing a screw propeller B from off the shaft C.
The propeller jack A having been set right, that is to say, with the steel
slides flush with the ends of the box, it is placed between the storn
post D of the vessel and the propeller B. Should there be any space left
between the propeller jack and the propeller it is packed with strips of
metal, so that the tool may be firmly fixed and begin its work directly
force is applied. The lever handle E is then placed over the heptagonal
portion of the shaft, and an effort made to bring the long diameter of
the elliptical portion of the shaft in a line with the centro of the vessel.
Should there not be sufficient room however to bring the lever handle
round to the quarter turn, as is very frequently the case, the handle after
travelling as far as the nature of the place will admit is readjusted, the
upper part of the shaft being made heptagonal in cross section for
that purpose, and an effort made again and again until effected, when
the steel slides are necessarily forced outward, starting the propeller from
its bed. The propeller jack is then re-arranged, and a packing piece i
introduced, the lever handle is again turned, and the performance
repeated until the screw propeller is sufficiently displaced from its bed to
be easily removed.
Should manual labour be found inadequate to turn the lever handle I
fasten suitable tackle to the shackle at the end thereof, and by con-
necting the other end of the tackle to the rudder post a greater power
can be exerted. But where it is impossible from the nature of the
locality or from other reasons to employ tackle, I then substitute a
modification of my Invention, as shewn in Figures 8 and 9. Here it
will be seen that the body or box a has a long projecting arm g, having
a pivot 7 near the end, in which works the axle of the hand wheel h,
forming part of the screw k. On the lever handle E will also be seen a
similar pivot, but in this case the head is cut to receive the worm of

page_text: the screw k, consequently when the hand wheel is turned the lever
handle is brought nearer to the arm g, bringing with it the long diameter
of the elliptical portion of the shaft into a line with the line F, G,
this being the line of thrust.
My Invention is equally well adapted to many purposes where the
engineer for the want of room or space is unable to use the ordinary
appliances. As an instance of this I have shown in Figure 7 how my
propeller jack can be employed to force or remove a piston rod from the
piston. Here the piston O is suspended by bolts m, m, to the cross
piece N placed across the end of the cylinder, and forming an abutment
for the jack A, which is placed between it and the end of the piston
rod P. On referring to the Figure it can readily be understood how by
pulling over the lever handle E by manual labour or tackle, as shewn,
the piston rod is forced from the piston in a manner similar to that
described when speaking of removing a screw propeller.
Having now described and particularly ascertained the nature of the
said Invention, and in what manner the same is or may be used or
carried into effect, I claim as the Invention secured to me by Letters
Patent as aforesaid, the means of removing screw propellers from their
shafts, substantially as and for the purposes herein-before described.
In witness whereof, I, the said Thomas Fenwick Reed, have here-
unto set my hand and seal, this Twenty-fourth day of September,
in the year of our Lord One thousand eight hundred and seventy-
five.