IMPROVE. MENTS IN SHAFT COUPLINGS
Year: 1868

page_text: LETTERS PATENT to Martin Benson, of 14, Hinde Street, Manchester
Square, in the County of Middlesex, for the Invention of "IMPROVE.
MENTS IN SHAFT COUPLINGS."-A communication from abroad by John
Richards, of Cincinnati, Ohio, United States, North America.
Sealed the 27th April 1869, and dated the 29th October 1868.
PROVISIONAL SPECIFICATION left by the said Martin Benson at the
Office of the Commissioners of Patents, with his Petition, on the
29th October 1868.
I, MARTIN BENSON, of 14, Hinde Street, Manchester Square, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SHAFT COUPLINGS," a communication, to be as
follows:-
The nature of this Invention consists in constructing a shaft coupling
with an internal split sleeve or tube to fit the ends of the shafting with
external conical ends, the larger diameter being in the centre and the
smaller at the ends of said sleeve; each end of the sleeve is fitted
with a compressing or tightening shell, and furnished with means.

page_text: for screwing their inward ends together, which firmly presses the
internal split sleeve to the shafting owing to its conical-shaped ends.
The internal split sleeve is constructed sufficiently thin and light in
its cross section to be compressed concentrically to fit shafts of slightly
varying diameters, and in so constructing the outer or compressing
shells that the strain will fall equally on each end, so connecting them
that they will represent the continued strength of shafts through the
coupled point. Couplings of this class have heretofore been constructed
with the internal sleeve to constitute their strength, while the outer
shell or compressing mechanism have no connection and act inde-
pendently on each end of the sleeve; this involves making the central
sleeve surrounding the shaft so heavy and stiff that it can only be closed
as two semicircles, and consequently can only fit a shaft of fixed and
specific diameter, and when closed upon a smaller shaft has only a line
of contact in place of binding at all points of the circumference of the
shaft. In this coupling the sleeve is made thin with but little metal
in its cross section, therefore it can be compressed to fit shafts of
different diameters and adapt itself to irregularities incident to turning
and finishing, while the outer or compression shells are so connected
that they become the real connection between the shafts, and represent
their continual strength through the coupling joint; they are also
arranged in such a manner in connecting them that one will draw upon
the other, making the compression equal on each 'shaft.. By this
arrangement a coupling, as a whole, can be constructed with less
metal and of smaller diameter for the reason that the internal sleeve,
if constructed heavy enough to form the strength of the coupling,
would increase the diameter of the outer shells proportionately without
adding to its strength. By connecting and forming a whole of the outer
shells any cross strain upon the coupling falls upon the outer com-
pressing shell at its extreme diameter instead of the central sleeve,
making the coupling as strong as the common flange connection. The
compressing shells may be connected by means of screw bolts, nuts, and
flanges, or a threaded ring nut made to take hold of a flange on one of
the compressing shells and a screw provided on the other for receiving
the ring, and thereby draws the inward ends of the two compressing
shells together.

page_text: but for economy in construction and simplicity of application the
method of making the coupling herein-before described will be used.
When the shafts to be coupled together are intended to be the same
diameters some of these methods herein-after described may be used
to advantage when the two shafts to be coupled together are of different
diameters; for instance, to accomplish this the two compressing or outer
shells or cones can be made in one piece and conically bored out, so
that the smaller diameters of the cones will be in the centre from each
end of the compressing shell. Each end of the shafts to be coupled
are provided with split or divided cone pieces fitted thereon with their
smaller diameters or ends turned inward and made to fit in the conical
ends of the compressing shell before described; and by means of screw
bolts passing longitudinally through the outer compressing shell in holes
or slots made for the purpose the split sleeves or cones on the ends of
the shafts are forced into each end of the compressing shell and around
the shafts, thereby firmly clamping and coupling the ends of the two
shafts together. The conical split or divided sleeves on the ends of the
shafts for any one coupling made after this method may be of different
internal diameter for coupling shafts of different dimensions together
by the same compressing shell. Keys or keepers will be used in
connection with the split sleeves or cones and ends of shafts to prevent
the sleeves from slipping longitudinally or rotatively. It will be
necessary to use keys or keepers for this purpose in connection with all
the different modes of applying the compressing principle for coupling
purposes.
Another form of sleeve for applying the principles of compressing
for coupling is by making the larger diameter of the cone in the centre
of the compressing sleeve from its two ends; this will necessitate making
the coupling shell in two halves and bolting or screwing them together
after being placed on the shaft. For compressing shells of this kind
the ends of the shafts will be provided with split conical sleeves with
the larger diameters of the cones placed inward, while the outer ends
of these cones will project beyond the ends of the compressing shell
and be provided with screw threads for receiving nuts; the nuts aré
forced against the ends of the compressing shells, which draws the split
cones outward and firmly presses them in the compressing shell and
around the shaft, thereby coupling the two ends of the shafts together.

page_text: By this process shafts also of different diameters may be coupled together
by the same compressing.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Martin Benson in the Great Seal Patent Office
on the 29th April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MARTIN
BENSON, of 14, Hinde Street, Manchester Square, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of October, in the year
of our Lord One thousand cight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Martin Benson, Her special licenco that
I, the said Martin Benson, my executors, administrators, and assigns, or
such others as I, the said Martin Benson, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands, and
Isle of Man, an Invention for "IMPROVEMENTS IN SHAFT COUPLINGS," a
communication to me from abroad by John Richards, of Cincinnati,
Ohio, United States, North America, upon the condition (amongst
others) that I, the said Martin. Benson, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Martin Bonson, do hereby declare
the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and
by the following statement:-
The nature of this Invention consists in constructing a shaft coupling

page_text: means for
with an internal split sleeve or tube to fit the ends of the shafting, the
said sleeve having external conical ends, the larger diameter being in
the centre and the smaller at the ends; each end of the sleeve is fit
with a compressing or tightening shell furnished with
screwing their internal ends together, which firmly presses the internal
split sleeve to the shafting owing to its conical-shaped ends. The
internal split sleeve is constructed sufficiently thin and light in its cross
section to be compressed concentrically to fit shafts of slightly varying
diameters, and in so constructing the outer or compressing shells that
the strain will fall equally on each end of the coupling, so connecting
them that they will represent the continued strength of the shafting
through the coupled point. Couplings of this class have heretofore
been constructed with the internal sleeve to constitute their strength,
while the outer shell or compressing mechanism have no connection
and act independently on each end of the sleeve; this involves making
the central sleeve surrounding the shaft so heavy and stiff that it.can
only be closed as two semicircles, and consequently can only fit a shaft
of fixed and specific diameter, and when closed upon a smaller shaft has
only a line of contact in place of binding at all points of the circum-
ference of the shaft. As before stated the sleeve of the coupling is made
thin, with but little metal in its cross section, therefore it can be com-
pressed to fit shafts of different diameters and adapt itself to irregularities
incident to turning and finishing, while the outer or compressing shells
are so connected that they become the real connection between the
shafts, and represent their continual strength through the coupled
point; they are also arranged in such a manner in connecting them that
one will draw upon the other, making the compression equal on each
shaft. By this arrangement a coupling, as a whole, can be constructed
with less metal and of smaller diameter, for the, reason that if the
internal sleeve is constructed heavy enough to form the strength of the
coupling it would increase the diameter of the outer shells proportionally
without adding to its strength. By connecting and forming a whole
of the outer shells any crosss trains upon the coupling falls upon the
outer compressing shells at its extreme diameter instead of the central
sleeve, making the coupling as strong as the common flange connection:
The compressing shells may be connected by means of screwed bolts,
nuts, and flanges, or a threaded ring nut made to take hold of a flange
on one of the compressing shells and a screw provided on the other for

page_text: receiving the ring nut, and thereby drawing the inward ends of the two
compressing shells together.
In the accompanying Drawings similiar letters of reference refer to
corresponding parts.
Figure 1 is a longitudinal section; Figure 2 is a transverse section;
and Figure 3 represents a side elevation of the coupling; Figure 4 and 5,
different views of the coupling showing the compressing shells drawn
together by bolts and nuts; Figure 6 is a longitudinal and Figure 7 a
transverse section of the split slecvc.
A, A, are the ends of the shaft joined together by the coupling;
B, B, is the split sleeve usually made of cast iron and bored out to fit
loose enough so that it may be placed on the shafting without driving
or forcing, as required in the ordinary flange coupling, when keyed on ;
the sleeve is provided with a slit S, S, from end to end to admit of its
being concentrically compressed firmly to the shafting, which is effected
in the following manner :-The external ends of the sleeve are made
tapering, as represented in Figure 1, and the compressing shells C, C;
are bored to a corresponding taper to fit the ends of the sleeve; allow-
ance is made in boring the shells, that when their inner ends are
drawn together they will not meet by about one-cight of an inch; this
is donc so that the greatest possible compressive strain may be brought
on the shafting through the medium of the split sleeve. The compressing
shells are drawn together by the ring nut D, which draws them up
truly on all sides and causes a uniform compressive force to be exerted
on each end of the shafting. The ring nut is screwed up by the spanner
wrench J, represented in Figure 2. F is a wrough iron or steel key
placed through a slot in the sleeve and fit in keyways in the end of the
shaft, as represented in Figure 1 and 2; this key is used for the double
purpose of preventing the coupling from turning in the process of
tightening it on the shafting, and for partly transmitting the strain
from one to another length of shafting through the medium of the
coupling; the key is fit loose so that it can be dropped into its place
without force, and is prevented from getting away by the shells C, C,
pressing against its outer edge, as represented in Figures 1 and 2.
The method of drawing the compressing shells on the split sleeves by
bolts and nuts, as represented in Figure 4 and 5, is defective com-
pared with the use of the ring nut for the same purpose; by using the

page_text: bolts it necessitates making the sleeve much larger to obtain the required
strength, and consequently proportionally increasing the compressing
shells without adding additional strength to the coupling, and by
increasing the thickness of the sleeve it cannot be compressed to fit
all points of the shaft; I therefore advise the use of the ring nut in
all cases.
Having described the nature of my Invention, and the manner of
carrying the same into effect, what I desire to secure by Letters Patent
is,-
Firstly. I claim the split sleeve B with tapered external ends as
represented, and for purposes here-before described.
Secondly. I claim the ring nut D for drawing the inner ends of the
compressing shells together on the split sleeve, constructed as represented
and for the purposes before described.
Thirdly. I claim the split sleeve B, compressing shells C, C, and
ring nut D, combined as represented, for short couplings, and operated
in the manner and for the purposes herein-before described.
In witness whereof, I, the said Martin Benson, have hereunto set
my hand and seal, this the Twenty-eight day of April, in the year
of our Lord One thousand eight hundred and sixty-nine.