IMPROVEMENTS IN SHAFT COUPLINGS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, STEPHEN ALLEY, of the Sentinel Works, Polmadie, Glasgow, in the County
of Renfrew, North Britain, Engineer, do hereby declare the nature of my said
invention for "IMPROVEMENTS IN SHAFT COUPLINGS" and in what manner tho
same is to be performed, to be particularly described and ascertained in and by
the following statement that is to say :-
My said Invention has for its object the construction of a simple and improved
coupling to be applied to a line of shafting such as that of a screw propeller, for
connecting the lengths of which the line is made up, in such a manner that tho
shafting may accommodate itself to slight deviations from a rigidly straight line,
and thus avoid the excessive strains often acting on shafting having the ordinary
rigid couplings.
In carrying out my Invention the adjacent ends of two shaft lengths which are
to be coupled have enlargements forined on them somewhat like those of ordinary
rigid couplings, and one shaft end has formed at its centre a projection or head
having a spherically-shaped annular surface from the neck to the widest part.
A disk or plate which is in halves and is inserted between the two shaft ends is
nade with a central opening having a counterpart surface fitting and working on
the spherical surface of the head described as formed at the centre of one of the
shaft ends, and this disk is fixed to the other shaft end by bolts, the same bolts
being continued through holes in the enlargement on the shaft end having the
central head. The outer part of the head is formed with a slightly projecting
centre to bear against the centre of the other shaft end, and as much play is
allowed at the proper parts as is considered necessary to allow of the axes of the
shaft lengths becoming slightly inclined to each other without interfering with the
rotation.
The proportions of the parts may be varied to suit the requirements of different
cases, but on the accompanying sheet of explanatory drawings there is delineated
a coupling as made according to my Invention and suitable for the line of shafting
of a screw propeller.
Figure, 1, on the accompanying sheet of drawings is a transverse section,
figure, 2, is a side elevation figure, 3, is a longitudinal section and figure, 4, is
a transverse section but showing a view of the coupling opposite to that shown in
firure. 1.

page_text: The adjacent shaft ends 5, 6, have enlargements, 7, 8, formed on them, and one
shaft end, 5, has formed at its centre a projection or head, 9, the inner surface of
which is spherically shaped. On this splicrically shaped surface there is made to
fit and work a counterpart surface formed round a central opening in a disk or
plate, 10, which is made in halves and is interposed between the shaft ends.
Strong bolts, 11, are passed through the enlargements, 7, 8, and through the
disk, 10, and the bolt holes in the disk are made conical as are also the
corresponding parts of the bolts, so that when the bolts are screwed up by means
of their nuts, 12, they fix the disk, 10, rigidly to the enlargement, 8, of the shaft
end, 6. The bolts are made with parts, 13, extending through holes in the
enlargement, 7, of the other shaft end, 5, and whilst these bolts serve for
transmitting the rotative or torsional strain the combination of the spherical
head, 9, with the disk, 10, serves for tying the shaft lengths together longi-
tudinally. The parts are proportioned so as to leave slight space between
the disk, 10, and the shaft end, 5, and space for slight angular movement is
provided between the outer surface of the spherical head, 9, and the central
part, 14, of the shaft end, G, there is however a rounded projection at the centre
of the head, 9, which is in contact with the centre, 14, and which serves for
transmitting longitudinal thrust. The holes for the bolt ends, 13, in the
enlargement, 7, of the shaft end, 5, are slightly elongated in radial directions
to allow of the slight angular movements of the bolts when the shaft lengths
are slightly inclined to each other. The parts, 13, of the bolts, and the holes they
are in, in the enlargement, 7, may be made with flattened sides to give increased
bearing surfaces.
Having now particularly described the nature of my said Invention and in what
manner the same is to be performed I proceed to particularly ascertain the same
by declaring that what I claim is
The combination in a shaft coupling of enlargements on the shaft ends with
bolts fixed in one enlargement and capable of slight movements in holes in the
other enlargement also with a spherical head at the centre of one shaft end and
with a disk or plate engaging upon the said spherical head and fixed to the other
shaft end substantially as and for the purposes herein before described.
Dated this sixteenth day of January 1884.
EDMUND HUNT,
Applicant's Agent.