Year: 1886

page_text: Date of Application, 11th Oct., 1886.
Complete Left, 9th July, 1887.
Complete Accepted, 9th Aug., 1887.
I, JOSEPH SINCLAIR FAIRFAX, of 433 Strand, London, in the County of Middlesex,
Consulting Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to the construction of built up cranks, and by the same
means, to the connecting together of shafts.
In the construction of heavy cranks, especially those intended for marine engines,
it is found desirable for many reasons to build them up of several pieces, instead of
making them out of solid forged masses. The method usually employed is to key the
arms upon the main shafts or axles and to secure the pins within eyes in the same
manner. As a precaution against working loose, the arms are sometimes shrunk
upon the shafts and pins; and where the number of parts to be so treated are
numerous; as in the case of two and three throw cranks; considerable expense is
incurred in fitting the several parts together, keeping them true in line, and arranging
the cranks at the required angles with each other. A further difficulty is that this
system of construction does not lend itself readily to the carrying of spare parts to
repair damages at sea.
In my invention I bore out the boss of each crank to the size required and then
shift the arm slightly out of centre upon the face plate of the lathe or boring machine
and rebore it or recess it, a short portion of its depth, so as to be eccentric with its
first or true bore. The eye of the crank arm is similarly treated, and both the shaft
and pin ends are turned with a corresponding portion out of centre, (or eccentric with
the main axis), so as to fit into their respective places. By making the parts, and
amount of eccentricity, of standard dimensions throughout, the interchangeable system
may be followed; and spare parts can be carried in case of break down."
All the work being done in the lathe exactness in every dimension becomes easy;
and if it be required to shrink the arms upon their shafts, a slight taper in the reverse
direction is preferred to prevent the arms working loose end ways: the eccentric
portion being virtually a circular key with large bearing surface and well fitted,
ensuring the transmission of power.

page_text: As the eccentric portion may be turned upon the shaft at any angle required, the
crank arms may be readily placed at the desired angles so as to suit two, three, or
four throw cranks. Should it be required to couple together two or more complete
. cranks, or shafts, (either screw or other shafts), the junction is effected by turning an
eccentric pin on the end of each shaft, and boring out a solid coupling piece to fit the
shafts, but with a fin or web in the centre of its length at least equal in thickness to
the length of the projecting pins. This web is also bored out eccentrically to fit the
eccentric pins, and is thus capable of transmitting the power from one shaft to the
other.
The coupling piece may be dispensed with by turning the end of one shaft so as to
form an eccentric pin, as last described, and then bore out the end of the adjoining
shaft to fit the same. This is best done where the ends of the shafts are enlarged,
as in screw shafts; and although bolts or plates may be used to prevent end
movement, they are not absolutely required in any of the cases named. A loose
fit, and slightly rounded contact surfaces may be employed, when there is any
tendency to flexure in the axial line of the shafts.
Dated this 25th day of Santamban 1002

page_text: also to the Coupling together of Shafts.
I, JOSEPH SINCLAIR FAIRFAX, of 433 Strand, London, in the County of Middlesex,
Consulting Engineer, do hereby declare the nature 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 :-
This invention relates to the construction of built up cranks, and, by the same
means, to the connecting together of shafts.
In the construction of heavy cranks, especially those intended for marine engines,
it is found desirable for many reasons to build them up of several pieces, instead of
making them of solid forged or cast masses. The method usually employed is to key
the arms or webs upon the main shafts or axles, and to secure the pins within the
eyes of the webs in the same manner. As a precaution against working loose the
arms are sometimes shrunk upon the shafts and pins (frequently without keys);
and in the case of two and three throw crank shafts, considerable expense is incurred
in fitting the several parts together, keeping them true in line, and arranging the
cranks at the required angles with each other. A further difficulty is that the system
of construction does not lend itself readily to the carrying of spare parts to repair
damages at sea.
In my invention I bore out the boss of each crank arm or web to the size required
and then shift the arm slightly out of centre upon the face plate of the lathe or boring
machine and rebore it or recess it about one third of its depth, so as to be eccentric
with its first or true bore which the shaft is to fit. The eye of the crank arm or web
is similarly treated; the eccentric recesses being both on the same side or face of the
web. The pin and ends of the shafts are turned to fit the webs in a corresponding
manner, the eccentric collars on the same, or portions eccentric with the axial line of
the shafts and pin being made to fit accurately into the recesses above named. By
making the parts, and amount of eccentricity of standard dimensions in all cases, the
interchangeable system may be followed and the minimum number of spare parts
carried to repair damages in case of break down.
As the eccentric portion at the end of the shafts may be turned at any required
angle with the central line of the crank arms, two or more cranks may be coupled
together by a suitably made coupling piece or the several crank arms of two, three,
or four throw cranks may be readily placed at any angle required for the proper
application of the turning force. In coupling together two or more complete cranks,
or pieces of shafting, (either screw shafts or any other kind), the junction is effected
by turning an eccentric pin on the end of each shaft, and boring out a coupling piece
to fit the shafts in their ordinary parts. The coupling piece is formed with a fin or
web in the centre of the bore of a thickness at least equal to the combined lengths

page_text: of the two eccentric pins already mentioned. The web is also bored out to fit the
diameter of each pin and with the same degree of eccentricity; and thus the
coupling piece is capable of transmitting power from one shaft to the other without
the aid of any bolts, nuts, or keys, ordinarily used.
The coupling piece itself may be of a sleeve form to embrace the ends of the
two shafts, as last described; or may take the form of a pin, the shaft ends being of
socket shape, with the same arrangement of eccentric portions provided as before.
But the coupling piece itself may be dispensed with by forming one end of a shaft
as a solid ended socket, and the end of the adjoining shaft with an eccentrically
turned pin or collar thereon, fitted into the correspondingly turned socket ended
shaft, and thus engaging the two shafts as before described.
These connections may have bolts or plates combined with them to prevent end
movement, though they are not absolutely required in any of the cases stated.
Where there is any tendency to flexure in the axial line of the shaft, the parts may
be less tightly fitted than usual, and have slightly rounded contact surfaces.
As all the work of fitting can be done in the lathe it becomes easy to obtain
absolute exactness in all the dimensions. Where it is desirable to shrink the arms
upon their shafts or pins, it can be as readily done as in the case of ordinary
built up cranks; and as an additional precaution against end play, a slight taper in
the reverse direction may be given to the parts before the arms are shrunk on. It
will be seem, however, that the journals upon the shafts and the connecting rod
end upon the pin will alone keep the parts in their relative positions without the aid of
bolts, nuts, plates or the like; and by removing the brasses and connecting rod, all
the parts may be disconnected, a defective piece removed, and the damage repaired
at sea with the greatest facility. This may be done even where the parts have been
shrunk together, as heat may be easily applied to the arms, and the several parts being
made interchangable there are no fitting of bolts, keys or other loose pieces. Each
of the eccentric parts becomes a key and the correspondingly bored part a keyway;
and being well fitted to each other, with large bearing surfaces, in solid material, the
arrangement ensures the due transmission of power.
In the drawings annexed Fig. 1 represents a crank shaft according to my invention,
one of the webs or arms being shown in section with the eccentric portion of the
shaft a and pin b denoted by the letter .. The crank arm or web c is also shown by
a face view of the same in Fig. 2, the portion bored out to receive the eccentric collars
being also denoted by r and it will be observed that they are both on the same face
or surface of the web c. The extreme ends of the two shafts a, a, are turned down to
form eccentric pins thereat, (which may be done upon the same centres on which the
eccentric collars are turned), the lower one being joined by a coupling piece d to a
shaft d also turned down at the end to correspond with the end of the shaft a to which
it is connected. The coupling piece d is shown in section upon the shaft ends in
its working position, and an end view is denoted by Fig. 3; and it will be noted that
the connection between the two shafts is made solely by this coupling d; the eccentric
portions throughout being indicated by .c.
In Fig. 4 is shown an end view of a shaft of a socket form, which is bored out to
receive the end of the shaft a (upon which it is shown) in a corresponding manner to
the coupling piece d, thus avoiding any loose piece. In Fig. 5 an internal coupling
piece is shown as connecting together the two hollow shafts h, h, which shafts are
bored at the ends in a similar manner to the solid ended shaft and the coupling
piece d. The solid piece g has two eccentric pins x, x turned thereon at the ends, and
à central collar of the same external diameter as the shafts h, h, but this collar may be
dispensed with.
The crank shaft is shown with journals at a, a, turned down below the general
diameter of the shaft pieces. Should such journals be used, the brasses or bearings
would have to be removed to allow an end movement of either shaft a; but this being
done either crank arm can then be readily removed from the shaft or crank pin end
on which it is fitted for the purpose of repairing or replacing any damaged portion;
and as there are no other fastenings to undo it will be seen that repairs or removals of

page_text: any of the parts can be done at sea with great facility. The crank pin and the journal
bearings keep the parts from end movement.
I am aware that parts of shafts have been provided with eccentric portions fitted
into recesses bored upon the sides of crank arms, and that eccentrically formed or
arranged pins have been used in building up crank shafts; but I am not aware of it
having been done with as few pieces, or in as simple, or, the same manner, as by this
invention; nor do I believe that screw shafts, or the like, have been coupled together
in the manner indicated before this invention.
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 of parts comprising a crank or crank shaft when constructed.
substantially as described.
2. A crank arm or web having two holes bored through the thickness of the same
for the reception of the shaft and pin respectively, with an eccentric recess bored out
at each hole, substantially as described.
3. A crank arm or web having two holes bored through the thickness of the same
and an eccentric recess at each hole situated on the same face of the web substantially
as described.
4. A crank having one or more arms or webs, the pin and shaft or shafts of which
are attached or secured in working by turned eccentric keys so arranged that the
crank may be taken in pieces by removing the bearings, substantially as and for the
purpose specified.
5. The method of coupling together shafts, substantially as and for the purpose
described.
6. A coupling piece for connecting shafts together fitted to the same and adapted
to transmit motion from one shaft to another, substantially as described.
7. An external or internal coupling or connecting piece having one or more
eccentric portions therein or thereon and adapted to fit upon or within correspondingly
turned or bored portions of a shaft or shafts, substantially as described.
8. The combination of a crank shaft having an eccentric portion turned upon the
end thereof with a crank arm having a hole bored through the same, and an eccentric
recess adapted to fit the shaft whereby bolts, nuts, or separate keys are dispensed with,
substantially as described.
9. The combination of one or more shafts with one or more crank arms, and a
crank pin, comprising a built up crank; the said parts being without other loose parts
and adapted to transmit motion by means of eccentrically formed circular keys and
keyways, whether they are shrunk together or not; substantially as required.
10. The various forins and arrangements shown upon the annexed drawings.