Year: 1885

page_text: I, JOHN GARDNER, of 6 High Terrace, Darlington, in the County of Durham,
Engineer, do hereby declare the nature of this invention, to be as follows:-
My invention has for its object the making of a new or improved coupling for
screw propeller shafts, which while being equally strong to the couplings heretofore
in use, would yield in the case of strain and vibration being brought on the
shafting by the bending of the vessel in stormy weather or otherwise, and thus
prevent breakage of the shaft.
The
And the nature and novelty of the invention as applied direct to the inner end
of the screw propeller shaft inside the stuffing box of the stern tube of the shaft to
connect it to the main shafting inside, consist all as follows:-in forming a spherical
solid ball on the inner end of the propeller shaft and fitting on this a hollow semi-
spherical outer coupling piece with a deep socket piece on the shaft beyond the ball
slightly wider at the outer part so as to allow the shaft to roll slightly within this
socket part, while the ball perfectly fitted the interior of the spherical part.
central part of this hollow spherical coupling piece would be formed with a large
strong flange, and jointed and bolted round the centre of the sphere to a similarly
flanged hollow spherical solid coupling piece forined on a part of the shaft inside
the ship, which would have an ordinary flange at its extreme inner end for.
coupling to the shaft next it by a corresponding flange with strong bolts in the.
same manner as the shafts are at present coupled. As so far described this hollow
spherical coupling piece would fit tightly on the spherical ball, allowing no end.
motion, but a slight degree of lateral motion in the case of the shafting getting out
of line by the vibration or bending of the ship, but would not turn the screw shaft.
To effect the turning of the screw shaft by the hollow spherical coupling pieces
I fit, two, three, four or more radial driving blocks or pieces with strong rectangular
stems fitted tightly in slots formed for them half through each flange and joint
part of the coupling pieces, preferably with one of the bolts of the flanges passed
through each stem to retain it firmly in position; and further in forming on the
inner end of each driving block a broad oval or elliptical driving head, sunk into a
corresponding oval recess formed in the ball, these ovals having their major axis
in the longitudinal direction of the shaft, and fitting each other laterally but
having sufficient play longitudinally as to allow of a slight universal motion while

page_text: being quite tight in the driving or turning direction. These driving blocks and
their heads would be formed of the best steel to stand wear, and the oval recesses
on the minor axis sides into which they work would be fitted with bearing steel
blocks, preferably dovetailed to securely retain them in position; and the bearing
surfaces of these driving heads and blocks would preferably be tempered to stand 5
the wear in transmitting the power of the whole shaft through them.
D
A. 11
T
100K
Improvements in Couplings for Screw Propeller Shafts.
I, JOHN GARDNER, of 6 High Terrace, Darlington, in the County of Durham,
Engineer, do hereby declare the nature of my 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 accompanying sheet 1
of Drawings, and to the reference letters and figures marked thereon; that is
to say :-
My said invention has for its object the making of a new or improved coupling
for screw propeller shafts, which, while being equally strong as compared with the
couplings heretofore in use, will yield in the case of strain and vibration being
brought on the shafting by the bending of the vessel in stormy weather or other-
wise, and thus prevent breakage of the shaft.
And in order that the nature and novelty of my said Invention, and the manner
of carrying the same into effect or practice may be properly understood, I have
hereunto appended a sheet of Explanatory Drawings in which the same reference
letters indicate corresponding parts in the several figures where shown. Figures 1
and 2 are respectively an elevation partly in section, and a transverse section, of
one of my improved ball and socket couplings A and B, B¹, as suitable for the
inner end A of the screw propeller shaft A¹. The socket is made in two parts B, B¹,
and bolted together by the strong flanges B1, B1, and has formed on its inner
end B an ordinary flange- coupling B³, for attaching to those A³ of the main
driving screw shafts A leading to the engine. Figures 3 and 4 are an elevation
and transverse section respectively, corresponding to Figures 1 and 2, of the central
ball A on inner end of screw shaft A¹; and Figures 5 and 6 show a side and end
view, and an edge view respectively of one of the drivers C, c, as detached from
Figures 1 and 2, where they are shown fitted and bolted between the flanges B¹¹, Bul
for connecting and coupling and driving the two parts of the coupling A and B, B¹,
While Figures 7 and 8 show a side elevation, and sectional end view respectively,

page_text: of a modification of the socket part B, B¹, in which the socket part B, is made in
two halves and bolted together by longitudinal flanges 61, suitable for coupling
the driving screw shafts A within the vessel, which have the ball A on one end,
and a flanged coupling A³ on the other, or on the end of the motive driving crank-
shaft.
Referring to Figures 1 to 6 of these Drawings:-As applied direct to the inner
end of the screw propeller shaft A¹ inside the stuffing box of the stern tube of the
shaft, to connect it to the main shafting A' inside, my improvements consist all
as follows:-In forming a spherical solid ball A on the inner end of the propeller
shaft A', and fitting over this the hollow coupling B, B¹, having the hollow
semispherical outer coupling piece B formed with a deep socket piece 6, on the neck
of the shaft A beyond the ball A, slightly wider at the outer part b¹, so as to
allow the shaft and ball A to roll slightly within this socket part 6', B, while the
ball A perfectly fits the interior of the hollow spherical coupling part B, B'. The
central part of the outer hollow spherical coupling piece B, would be formed with
a large strong flange B, and jointed and bolted round the centre of the sphere A,
to a similarly flanged hollow spherical solid coupling piece B², formed on a part of
the shaft B' inside the ship, which would have an ordinary flange B³, at its extreme
inner end, for coupling to the shaft, as A³, next it, by a corresponding flange A³,
with strong bolts, in the same manner as the shafts are at present coupled. As so
far described, this hollow spherical coupling piece B, B', would fit tightly on the
spherical ball A, allowing no end motion, but only a slight degree of lateral motion
in the case of the shafting getting out of line by the vibration or bending of the
ship, but would not turn the screw shaft A¹. To effect the turning of the screw
shaft A¹ by the hollow spherical coupling pieces B, B¹, I fit two, three, four or
more radial driving blocks or pieces CC, (shown detached in Figures 5 and 6) with
strong rectangular stems C fitted tightly in slots formed for them half through or
into each flange B¹¹, B¹¹¹, and joint part of the coupling pieces B, B¹, preferably
with one of the bolts 6, of the flanges B", B1, passed through each stem C, to
retain it firmly in position. Further, I form on the inner end of each driving
block C, a broad oval or elliptical driving head c, which is sunk into a corresponding
oval recess c¹³, formed in the ball A. These oval drivers c, and their recesses o¹
have their major axis in the longitudinal direction of the shaft, and fitting each
other laterally without "play" in the direction of their minor axis, but have
sufficient play longitudinally as to allow of a slight universal joint motion within
the coupling while yet being quite tight in the driving or turning direction. These
driving blocks C and their working heads c, would be formed of the best steel to
stand wear; and the oval recesses c¹ in the ball A, on the minor axis sides, into
which they work, would be fitted with bearing steel blocks c³, preferably dovetailed
to securely retain them in position; as shown particularly in Figures 2, 3 and 4;
and the bearing surfaces of these driving heads c, and blocks c*, would preferably
be tempered to stand the wear in transmitting the power of the whole shaft
through them.
Referring to Figures 7 and 8; these show a somewhat different modification of
the outer socket part of the coupling B, B', suitable for the screw driving shafts A³
inside the ship, where there is a flanged coupling A³ on the one end of the shaft
and the ball A on the other end; in which case the outer socket piece B is made
in two halves, bolted together by longitudinal flanges 611, for being able to fit and
bolt this on in two parts after the shafts are in place in their bearings, and bolt
the same by the end flange B¹¹ to the flange B₁ of the other part B¹ of the of the
hollow coupling. Instend of using oval drivers C, c, as described and shown in
Figures 1 to 8, round drivers may be used with equal effect. Figure 9 shows an
elevation of the internal ball end A of the coupling on the end of one of the driving
screw shafts A³, in which such round drivers c, with square ends C₁, are shown as
employed, in place of the oval drivers shown in Figures 1 to 8, with slightly
elliptical holes c², for these drivers c, in the ball A. Figure 10 shows a side and
and view of one of these round drivers C¹ c, detached; the square or rectangular

page_text: part C¹ would be checked and bolted between the flanges B B all otherwise as
described in reference to the oval drivers C c. And completely round bushes c
might be fitted into each recess of the ball A for the round drivers c to work in,
made with their internal working surface slightly oval in the longitudinal direction
as shown in Figure 9.
These improvements would give a perfectly steady action in the driving or
turning direction and absence of end motion although the shafts were slightly out
of line either horizontally or laterally, and prevent much friction and abnorinal
strains within the shafts, and would thus be particularly applicable for long light
ships, where the ships and shafts would unavoidably vibrate or bend in rough
.weather.
Having thus 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
First. The general construction, and arrangement or combination of the parts of
solid and hollow spherical couplings, with drivers secured in the outer hollow
coupling, for screw propeller shafts, substantially as herein described, in reference
to and shown in the accompanying Drawings.
Second. The making of couplings for screw propeller shafts with an outer
spherical case in two parts, bolted together by strong flanges in the centre, having
drivers secured in these and inserted into recesses in the inner solid sphere,
substantially as herein described in reference to and shown in the accompanying
Drawings.
Third. In solid and hollow spherical couplings for screw propeller shafts, the
adaptation and' use of drivers, allowing a slight motion in the longitudinal direction,
but no play in the driving or twisting direction substantially as herein described
in reference to and shown in the accompanying Drawings.