IMPROVEMENTS IN CRANK AND OTHER SHAFTS'
Year: 1883

page_text: LETTERS PATENT to Alexander Jack of Liverpool in the County of Lancaster
Engineer and Hector Mac Coll of the same place Engineer for an Invention of
IMPROVEMENTS IN CRANK AND OTHER SHAFTS'
"
"
PROVISIONAL SPECIFICATION left by the said Alexander Jack and Hector
Mac Coll at the Office of the Commissioners of Patents on the 24th February
1883.
ALEXANDER JACK of Liverpool in the County of Lancaster, Engineer, and
HECTOR MAC COLL of the same place, Engineer, "IMPROVEMENTS IN CRANK AND>
OTHER SHAFTS
"
1
The invention relates more especially to the crank and main shafts of marine
engines and the objects are (a) so as to couple the ends of shafts that unequal
wear in the bearings shall not strain the shafts nor prevent them from being freely
rotated and (b) to exclude salt or sea water from acting on propeller and like shafts
where they are covered with brass or metal capable of producing galvanic action
in presence of salt or sea water.
For the above purposes we under the first part of our invention construct a
coupling of a disc of suitable metal having grooves or recesses at the opposite sides
thereof at right angles to each other and we form or surround such coupling with
a metal retaining ring. The ends of the shafts are formed with parallel sided
pieces or couplers which fit into and are free to slide in the cross grooves of the
couplings.
Under the second part of our invention we fit watertight rings or collars of iron
or other suitable metal on the shafts at the ends of the brass coatings in such
manner as to leave spaces which we fill watertight with zinc or other suitable
metal or substance. By preference the coatings and the collars or rings are so
beveled or shaped that there is a greater space next the shaft than towards the
exterior of coating collar or rings.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Jack and Hector Mac Coll in the Great Seal Patent Office
on the 24th August 1883.
ALEXANDER JACK of Liverpool in the County of Lancaster, Engineer, and
HECTOR MAC COLL of the same place, Engineer.
"IMPROVEMENTS IN CRANK AND
OTHER SHAFTS
"
The invention relates more especially to the crank and main shafts of marine
engines and the objects are (a) so to couple the ends of shafts that unequal wear in
the bearings shall not strain the shafts nor prevent them from being freely rotated
and (b) to exclude salt or sea water from acting on propeller and like shafts where
they are covered with brass or metal capable of producing galvanic action in
presence of salt or sea water.
For the above purposes we under the first part of our invention construct a
coupling of a disc of suitable metal having grooves slots or recesses at the opposite
sides thereof at right angles to each other and we form or surround such coupling
with a metal retaining ring. The ends of the shafts are formed with parallel sided
pieces or couplers which fit into and are free to slide in the cross grooves slots or
recesses of the couplings
Under the second part of our invention we fit watertight rings or collars of iron
or other suitable metal on the shafts at the ends of the brass coatings, in such
manner as to leave spaces which we fill watertight with zinc tin or other suitable
metal or substance. By preference the coatings and the collars or rings are so
bevelled or shaped that there is a greater space next the shaft than towards the
exterior of coatings collars or rings.
DESCRIPTION OF THE DRAWINGS
Fig 1 is a longitudinal, and fig 2 a transverse sectional view of a crank shaft
a a¹ a² portions of
constructed in accordance with the first part of our invention.
shaft constructed with parallel sided pieces or couplers b 61 62 having rounded ends.
The said pieces or couplers fit into and are free to slide in grooves slots or recesses
in the disc couplings cc. d, d' are rings formed in one piece with the couplings c c'
for the purpose of retaining the parts in correct position. The said rings may be
separate from the couplings and be secured thereto by set screws or equivalent
means. The grooves slots or recesses in the couplings are two in number one in
each side and at right angles or nearly so to one another. Adjustable wedge pieces
may be used to provide for wear in the slots. e bearings. If any unequal or
irregular wear in the bearings takes place so that the longitudinal axes of two
abutting portions of the shaft are not in the same straight line each portion of the
shaft is able to revolve freely in its bearings without being subjected to transverse
strains on account of the coupling sliding on the end pieces or couplers of the
shafts whilst rotating therewith and so adapting itself to any irregularities of
position of the said end pieces or couplers.
It will be obvious that although this part of our invention is specially applicable
to the crank and main shafts of engines it may also be applied with advantage
where shafts from unequal wear in the bearings or other causes are liable to be
deflected from a straight line.
Fig 3 is a longitudinal sectional view and figs 4 and 5 enlarged detail views of
a shaft provided with coatings and rings or collars under the second part of our
invention shaft. 9. g¹ brass coatings cast or shrunk thereon. h h¹ watertight

page_text: collars or rings of iron, other suitable metal such as steel may be used, i i spaces
between the coatings and collars or rings filled with zinc, tin, white metal, india
rubber, or other suitable substance capable of preventing sea or salt water from
reaching the shaft. The collar or ring his shown shrunk on; the collars or
rings h¹ are shown secured by set screws as would be the case when applied to
existing shafts. The space is wider next the shaft than towards the outside so
as to retain a metal filling more securely. The spaces i¹ are shown parallel sided
and are more suitable when india rubber or similar substance is used as filling.
Having now described and illustrated the nature of the said invention in such
manner that others will be enabled to carry our improvements into effect wo.
claim-
First. Crank and other shafts constructed substantially as herein specified for
the purposes setforth.
Second In crank and other shafts parallel sided pieces or couplers grooved
slotted or recessed couplings and retaining rings combined and operating substan-
tially in the manner and for the purposes setforth
Third. Propeller shafts constructed with coatings, and rings or collars disposed
substantially in the manner described for the purpose setforth.
In Witness Whereof We the said Alexander Jack and Hector Mac Coil have
hereunto set our hands and seals this twenty second day of August in the year of
Our Lord one thousand eight hundred and eighty three.
AT UVANDED TACK