IMPROVEMENTS IN THE MANUFACTURE OF CRANK SHAFTS FOR STEAM SHIPS
Year: 1883

page_text: LETTERS PATENT to James Russell of Cardiff in the County of Glamorgan
Marine Engineer for an Invention of IMPROVEMENTS IN THE MANUFACTURE
OF CRANK SHAFTS FOR STEAM SHIPS.
PROVISIONAL SPECIFICATION left by the said James Russell at the Office
of the Commissioners of Patents on the 9th August 1883.
JAMES RUSSELL of Cardiff in the County of Glamorgan, Marino Engineer,
"IMPROVEMENTS IN THE MAnufacture of CRANK SHAFTS FOR STEAM SHIPS"
This invention has reference to a construction of crank shaft designed to
obviate breakage or undue straining which sometimes occur in practice with
crank shafts as ordinarily made either from the bearings getting out of line, or
from the shaft itself getting out of truth from any cause such as heating.
According to this invention one end of the crank pin is made not in a piece
with the corresponding crank arm, but separate therefrom, and passes through a
brass bush, made in sections of a tapering form and which fits a hole or recess in
the crank arm end. The end of the crank pin that passes through the said bush
is parallel and is allowed a limited fore and aft play (say about 1/") to guard
against strain on the crank arm, such as might arise, for instance, owing to the
shaft working forward, or if there should be any slight cant or twist on the crank
pin when turning the centre the said play would allow for it. If the main bearings
should work out of true line, especially in an upward and downward direction,
the crank can be put on either the top or bottom centre and opposite sections of
the tapered bush be adjusted by moving the one in and the other out until each
bears on the pin.-Conveniently the bush is made in four tapered and flanged
sections adjustable by screwed pins working through tapped holes in the bush
flanges. The heads of the adjusting pins are counter-sunk into the face of the
crank arm and kept in place by a steel plate or flange which is let into the crank
face, and is fastened by four nail headed screw pins, and also by four studs with
square necks that fit into flanges to prevent the studs becoming unscrewed. The
adjusting pins have square ends and they also can be kept from turning by

page_text: locking any two together. And to guard against the crank having more than the
intended maximum fore and aft play I provide a steel cotter which passes
The
through the pin end, and through two opposite flanges of the bush.
free end of the crank pin is always supposed to be on the forward arm of the
crank in stern propelling vessels. The pin that passes through the bush instead 5
of being parallel may be curved slightly to better accommodate itself to any little
change in the relative positions of the parts in the event of there occurring a slight.
cant or twist.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Russell in the Patent Office on the 8th February 1884.
JAMES. RUSSELL of Cardiff in the County of Glamorgan, Marine Engineer,
IMPROVEMENTS IN THE MANUFACTURE OF CRANK SHAFTS FOR STEAM SHIPS
This invention has reference to a construction of crank shaft designed to obviate
breakage or undue straining which sometimes occur in practice with crank shafts
as ordinarily made either from the bearings getting out of line, or from the shaft
itself getting out of truth from any cause such as heating.
According to this invention one end of the crank pin is made not in a piece
with the corresponding crank arm, but separate therefrom, and passes through a
brass bush, made in sections of a tapering form and which fits a hole or recess in
the crank arm end. The end of the crank pin that passes through the said bush
is parallel or slightly barrelled and is allowed a limited fore and aft play (say
about ") to guard against strain on the crank arm, such as might arise, for
instance, owing to the shaft working forward, or if there should be any slight cant
or twist on the crank pin when turning the centre the said play would allow for
it. If the main bearings should work out of true line, especially in an upward
and downward direction, the crank can be put on either the top or bottom centre
and opposite sections of the tapered bush be adjusted by moving the one in and
the other out until each bears on the pin. Conveniently the bush is made in four
tapered and flanged sections adjustable by screwed pins working through tapped
holes in the bush flanges. The heads of the adjusting pins are counter-sunk into
the face of the crank arm and kept in place by a steel plate or flange which is let
into the crank-face, and is fastened by four nail headed screw pins, and also by
four studs with square necks that fit into the steel plate or flange to prevent the
studs becoming unscrewed. The adjusting pins have square ends and they also
can be kept from turning by locking any two together. And to guard against the
crank having more than the intended maximum fore and aft play I provide a steel
cotter which passes through the pin end, and through two opposite flanges of the
bush. The free end of the crank pin is always supposed to be on the forward arm
of the crank in stern propelling vessels. The pin that passes through the bush
instead of being parallel may be curved slightly to better accommodate itself to

page_text: any little change in the relative positions of the parts in the event of there
occurring a slight cant or twist.
Referring to the accompanying three sheets of illustrative drawings,
Fig 1 is a side elevation of part of a crank shaft with my invention applied
to it.
Fig 2 is an elevation at right angles to Fig 1 shewing the forward crank
arm, and
Fig 3 is a similar view with the forward crank arms removed
In describing the drawings I will assume the crank shaft to be employed in a
stern propelling vessel. The shaft A with the aft web or crank arm B and crank
pin C can be forged in one piece, but I prefer to make them in the manner of an
ordinary built up crank as shewn. The shaft A* with the forward web or crank
arm B* can also be forged in one piece but by preference are built up in the
ordinary manner as shewn. The free end D of the crank pin C passes through a
brass bush made in separate sections E¹ E² E³ E* of a tapering form and which fit
a hole or recess in the forward crank arm B*. The end D of the crank pin C may
be parallel, but I prefer to curve it slightly as shewn the better to accommodate any
little change in the relative positions of the parts in the event of there occurring
a slight cant or twist, and there is allowed to D a limited fore and aft play (say
about / inch). The four tapered sections of the bush have each a flango E
adjustable by screwed_pins F working through tapped holes in the said flanges.
The heads of the pins F are countersunk into the face of the crank arm B* and
are kept in place by a steel plate or flange G which is let into the crank face and
is secured by nail headed screw pins H and also by studs J with square necks that
fit into square holes in the plate G to prevent the studs becoming unscrewed.
Hexagonal nuts are screwed on to these studs and prevented from turning by a
split pin passing through a hole in each stud and along a groove in the hexagonal
nut. The adjusting pins F have square ends F* and are kept from working loose
by locking any two together. In order to guard against the crank having more
than the intended maximum of fore and aft play, a steel cotter K is passed through
the end D of the pin C and through two opposite flanges of the compound bush.
Figs 4 and 5 are similar views to Figs 1 and 2 shewing a modification of
crank constructed according to this invention, and Figs. 6 are detail views of
the cotter K
The more effectually to guide the segments E E E E two or more screw pins e
are screwed into each section and are provided with heads flattened on opposite
sides and sliding in longitudinal grooves d formed in the end D of the crank pin.
The cotter K has one corner of each of the brass bush sections held in check
by being let into those corners as far as the keep plate G. By having the cotter K
in this position every part is locked within the limits of the fore and aft play.
d* dx d* dx represent the quadrants of two circles the one described from the
centre of the boss and the other described from the centre of the crank pin for
instance when the crank is on the top centre. If any undue wear has taken placo
the direction of the wear can be easily ascertained if on applying the compasses
the circumferences of two circles are not equidistant from each other.
The cottar is retained in place by studs g-screwed into the plate G, and also by
means of a small screw M passing half in the cotter and half in the end D as is
well understood. The tapped holes formed in the plate G are useful for starting
the plate from its bed by means of longer studs.
Figs 7 and 8 are similar views to Figs 1 and 2 shewing another modification.
The bush is here shewn constructed in six sections E¹, E², E³,˜Eª, E³, Eº. The plate G
is secured to the web B* by means of the studs J, the nail headed screws being
dispensed with. Four independent cotters K or six if necessary secured by
studs g-and small screws M are shown, this arrangement being more suitable for
large cranks. Cranks constructed in a similar manner may be employed for
paddle steamers.
Having described the nature of my said invention and the manner of performing

page_text: it I hereby declare that what I consider to be novel and original and thereforo
claim as the invention secured to me under the Letters Patent first hereinabove
in part recited is :-
1. The use between the crank pin or a projection thereof and the crank arm
of a compound bush the section of which are adjustable substantially as and for
the purpose described above.
2. Constructing crank shafts substantially as described with reference to and
illustrated in Figs 1 to 3 inclusive, in Figs 4 to 6 inclusive, and in Figs 7 and 8
of the drawings for the purposes set forth.
In Witness whereof I the said James Russell have hereunto set my hand and
seal this twenty seventh day of December in the year of our Lord one thousand
cight hundred and eighty three