Improvements applicable in connection with Sorew-propeller Shafts.
Year: 1893

page_text: Date of Application, 27th Jan., 1893
Complete Specification Left, 24th Oct., 1893-Accepted, 25th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements applicable in connection with Sorew-propeller Shafts.
I, HECTOR MACCOLL, of Saxonia, Strandtown, County Down, Ireland, Engineer,
do hereby declare the nature of this invention to be as follows, that is to say :—
My said invention has for its object to diminish the inconvenienco, labor, time
expense, and risk experienced with the existing arrangement of the stern tubes and
bearings of screw-propeller shafts.
In carrying out my invention I employ a comparatively short stern tube, the outer
end being fixed in the ordinary way, and the inner end being supported and held
by a suitable plate frame. I fit within the stern tube a long bearing provided with
the usual liguumvitæ strips; and I arrange for drawing this bearing inwards out of
the stern tube. The bearing, with the stuffing box at its inner end is made in
halves, to allow of separation from the shaft after having been drawn in, for
inspection or repair, or renewal of the lignumvita. A space is provided between
the inner end of the stern tube and a watertight bulkhead sufficient for the
inward withdrawal and separation of the bearing.
Instead of the stern tube being a separate piece fixed to the stern frame, it
may be an elongated tubular boss formed on the stern frame. Or a stern tube
of the ordinary length may be employed, such tube being made in separato
pieces, namely a stern part, an inner part, and an intermediate part, the last
being made in halves and capable of separation to allow of the withdrawal
inwards of the stern bearing. Or, again, ‘a stern tube of ordinary length may
be employed, being made with an opening and cover at its middle part to give
access to the storn bearing.
With the improved arrangements the stern bearing can be examined and put
in order without removing the propeller or the stern longth of shaft, the
weight of these having simply to be suspended temporarily by any convenient
means, when the bearing is to be moved inwards.
Dated this Twenty-sixth day of January 1893.
EDMUND HUNT,
Applicant's Agent.
COMPLETE SPECIFICATION.
Improvements applicable in connection with Sorew-propeller Shafts.
I, HECTOR MACCOLL, of Saxonia, Strandtown, County Down, Ireland, Engineer,
do hereby declare the naturo of this invention and in what manner the 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 to diminish the inconvenience, labor, time,
expense, and risk, experienced with the ordinary arrangement of the stern tubes and
bearings of scrow-propeller shafts. And my said invention comprises devices and
arrangements admitting of the stern bearing boing drawn inwards and of its being
separated from the shaft in two or more parts, 30 that the stern bearing can be
examined and put in order without removing the propeller or the stern length of
shaft, the weight of these having simply to be suspended or supported temporarily
by any convenient means when the bearing is to be moved inwards.
My invention may be carried out in different ways examples of which are
delineated on an accompanying sheet of explanatory drawings which are hereinafter
roferred to in particularly describing my improvements.

page_text: Figure, 1, of the drawings is a sectional side elevation of one modification,
Figures, 2, and, 8, being enlarged transverse and longitudinal sections corre-
sponding to Figure, 1.
Figures, 4, and, 5, are transverse and longitudinal sections of a second
modification.
Figuro, 6, is a sectional side elevation of a third modification, aud
Figures, 7, and, 8, are enlarged transverse and longitudinal sections corresponding
to Figure, 6; and
Figures, 9, and, 10, are a transverse and longitudinal sections of a fourth
modification.
In these drawings the same reference letters are used to mark the same or like
parts wherever they are repented.
In carrying out my invention as shown in Figures, 1, 2, and, 3, of the drawings,
I fix a stern tube, A, of sufficient length for the stern bearing, with its after end
fitted into the eye of the boss, B, formed on the inner stern post, and with its
forward or inner end fixed, by flanges formed on it, to a strong transverse plate
frame, C. Within the stern tube, A, I fit a bearing tube, D, lined in the usual
way with lignumvita or other bearings strips, E, and provided with the usual
stuffing box, F, at its inner end. This bearing tube, D, is fitted into the stern
tubo, A, so that it can be withdrawn inwards from that tube, and it is made in
halves, by longitudinal divisions so that when it has been drawn from the stern
tube, A, the halves can be detached and separated from the shaft, G. A water-
tight bulkhead, H, is fixed across the stern space, at such a distance forward of
the stern bearing as to allow of the bearing tube, D, being conveniently handled
and separated from the shaft. When the two halves of the bearing tube, D, are
in position within the stern tube, A, they are bound together by that tube, so as
to be equivalent to an undivided tube.
Instead of the halves of the bearing tube, D, being held together by the outer
stern tube, A, such outer tube may be dispensed with, the halves of the bearing
tube being bolted together by means of flanges, J, formed on them as shown in
Figures, 3, and, 4, of the drawings. Or instead of such outer tubo (A) being
entirely dispensed with, a short one may be used enclosing only part of the bearing
tube, D; or a short tube or elongated tubular boss, K, may be formed by forging,
welding, or casting, upon the inner stern post, as shown in Figures, 6, 7, and, 8.
In any of the modifications hereinbefore described I may make provision for
tightening up the bearing surfaces by modifying the parts as shown in Figures, 9,
and, 10. In the arrangement shown in these figuros, which is otherwise the same
as that shown in Figures, 4, and, 5, grooves are formed in the bearing tube, D, to
receivo the bearing strips, E, of liguumvita and those grooves aro made of a slightly
tapering depth, being deepest at their inner ends, the lignumvita being made of
corresponding longitudinally tapering thickness. A ring, L, of comparatively thin
metal is fixed against the outor end of the bearing tube, D, and when the bearing
requires tightening the ring, L, is removed from the outer end and the stuffing
box, E, is removed from the inner end. The lignumvita strips, E, are then drivon
towards the outer end until sufficiently tightened by the wedge action of the
tapering grooves; after which any ends projecting at the outer end are cut off and
the ring, I, refixed, whilst any spaces at the inner onds of the grooves are filled up
with pieces of lignumvita and tho stuffing box, F, replaced. As the wear of the
bottom bearing surfaces is greatest, the fignumvita strips for that part are made
thicker and the strips and grooves are made with a somewhat quicker taper. This
arrangement for tightening up the bearing surfaces is applicable in cases in which
the bearing tube cannot be conveniently drawn inwards.
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 :-
1. The combination with the stern lougth of a screw-propeller shaft, of a bearing

page_text: tube divided longitudinally into a plurality of parts, adapted to be moved inwards,
with means for securing the parts together, substantially as and for the purposes
herein before described.
2. The combination of a bearing tube or of bearing surfaces for the stern length
5 of a screw-propeller shaft, with an inwardly removable or fixed tube of about
the length of the bearing substantially as and for the purposes hereinbefore
described.
3. In stern bearings of the kinds hereinbefore described, for screw-propeller
shafts, applying bearing strips of tapering thickness in tapering grooves sub-
O stantially as and for the purposes hereinbefore described.
DL: T
EDMUND HUNT,
Applicant's Agent.