IMPROVEMENTS IN SHAFT COUPLINGS "
Year: 1883

page_text: LETTERS PATENT to Thomas Leonard Ellis and Charles Leonard, both of
Coatbridge in the County of Lanark North Britain for an Invention of
"IMPROVEMENTS IN SHAFT COUPLINGS
"
PROVISIONAL SPECIFICATION left by the said Thomas Leonard Ellis
and Charles Leonard at the Office of the Commissioners of Patents on the
17th October 1888.
THOMAS LEONARD ELLIS and CHARLES LEONARD both of Coatbridge in the
County of Lanark North Britain. "IMPROVEMENTS IN SHAFT COUPLINGS
"
This Invention which relates to improvements in shaft couplings of the type
known as frictional shaft couplings consists of a hollow circular box whose interior
is bored out to a double conical hollow, that is to say, the interior surface of the
said box consists of two truncated cones whose least diameter is at the central part
of the box and whose widest diameter is at each end thereof.-For a sufficient
distance at each end the outside of the said box has a screw thread cut upon it and
a pair of hollow or box nuts are provided, one of which is screwed upon each end
of the said box.-Two tapered semicircular wedges fit into each truncated space of
the box and the several parts being placed in position upon the two pieces of
shafting which are to be coupled together the respective nuts are tightened and in
the act of being tightened force each pair of semicircular wedges into the box and
thereby they become tightened between the inner sides of the box and the
outsides of the shafts.-The tightening being continued until all the parts of the
coupling are brought to bear against each other and upon the shafts with
the requisite degree of rigidity.
Under a modified arrangement the coupling also consists of a hollow cylindrical
box, at the interior of the opposite ends of which a screw thread is cut for the
purpose of receiving a correspondingly screwed bush of sufficient length.-The
remaining portion of the interior of the box is made of a curved or tapered contour
narrowing towards the centre and into each of these hollows at the respective
ends of the box there passes an elastic curved shape ring each of which rings
surrounds the portion of the shaft to be coupled together.-As the screw bushes at
either end of the box are tightened within the same by being screwed up they
force the two spring rings down into the hollow of the box until they become
tightened with the requisite degree of rigidity between the box and the shafts.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Leonard Ellis and Charles Leonard in the Patent Office
on the 16th April 1884.
THOMAS LEONARD ELLIS and CHARLES LEONARD both of Coatbridge in the
County of Lanark, North Britain "IMPROVEMENTS IN SHAFT COUPLINGS
"
Our said Invention which relates to improvements in shaft couplings of the type
known as frictional shaft couplings, consists of a hollow circular box whose interior
is bored out to a double conical hollow, that is to say, the interior surface of the
said box consists of two truncated cones whose least diameter is at the central part
of the box and whose widest diameter is at each end thereof.-For a sufficient
distance at each end the outside of the said box has a screw thread cut upon it,
and a pair of hollow or box nuts are provided, one of which is screwed upon each
end of the said box.-Two tapered semicircular wedges fit into each truncated
space of the box, and the several parts being placed in position upon the two
pieces of shafting which are to be coupled together, the respective nuts are
tightened, and in the act of being tightened force each pair of semi-circular wedges
into the box and thereby they become tightened between the inner sides-of the
box and the outsides of the shafts.-The tightening being continued until all the
parts of the coupling are brought to bear against each other and upon the shafts
with the requisite degree of rigidity.
Under a modified arrangement, the coupling also consists of a hollow circular
box, at the interior of the opposite ends of which, a screw thread is cut for the
purpose of receiving a correspondingly screwed bush of sufficient length.-The
remaining portion of the interior of the box is made of a curved or tapered contour
narrowing towards the centre, and into each of these hollows, at the respective
ends of the box, there passes an elastic curved shape ring, each of which rings
surrounds the portion of the shaft to be coupled together.-As the screw bushes,
at either end of the box, are tightened within the same by being screwed up, they
force the two spring rings down into the hollow of the box until they become
tightened with the requisite degree of rigidity between the box and the shafts.
And in order that our said Invention may be properly understood, we now
proceed more particularly to set forth the system, mode or manner in or under
which the same is or may be used or practically carried into effect, reference being
had to the accompanying Drawings and to the Letters and Figures marked
thereon that is to say :-
Figure 1, represents in longitudinal section one form of shaft coupling constructed
according to our present invention.
Figure 2, represents the same in end elevation.
Figures 3, and 4, represent respectively in longitudinal section and end elevation,
a modified form of coupling constructed according to our present invention.
The shaft coupling represented at Figures 1, and 2, consists of the hollow
circular box a, whose interior is bored out to a double conical hollow, that is to
say, the interior surface of the said box a, consists of the two hollow truncated
cones b, and c, whose least diameter is towards or at the central part of the box a,
and whose widest diameter is towards or at each end thereof.-For a sufficient
distance at each end, the outside of the box a, has the screw thread d, cut upon it,

page_text: and the hollow or box nuts e, are provided, one of which nuts e, (as shewn on the
accompanying drawings) is screwed upon each screwed end d, of the box.a.-Two
tapered semicircular wedges f, fit into each truncated space b, and c, respectively of
the box a, and the several parts being placed in position upon the two ends of the
lengths of shafting g, and h, which are to be coupled together, the nuts e, are
tightened, and in the act of being so tightened, force each pair of semicircular
wedges f, into the box a, so that these wedges thereby become tightened between
the inner sides or surfaces of the box and the outer sides or surfaces of the shafts g,
and h, the tightening being continued until all the parts of the coupling are
brought to bear against each other and upon the shafts g, and h, with the requisite
degree of rigidity.-The hollow or box nuts e, are provided with the holes i, for
the insertion thereinto of the ends of levers or wrenches for facilitating the turning
of these nuts when being tightened up, or for loosening them when it is required to
disconnect the lengths of shafting. The coupling hereinbefore described may be
constructed in such a manner as to allow of it being used for coupling together the
ends of shafts of different diameters such as is represented at Figures 3, and 4, with
reference to the modified form of coupling now to be described
With reference to this modified arrangement, the coupling also consists of the
hollow circular box j, but in place of having the screw thread d, formed at the
exterior of the box, as in the coupling represented at Figures 1, and 2, the said
thread is formed at the interior thereof, for the purpose of receiving the corre-
sponding screwed bush k.-The remaining portion of the interior of the box j, is
made of a curved or tapered contour, narrowing towards the centre, and into each
of these hollows, at the respective ends of the box j, there passes the elastic curved
shape ring -These rings l, are cylindrical at the interior, so as to fit close upon
the shafts m, and n, which are to be coupled, when the said rings 1, are compressed
thereon. The outer sides or surfaces of the rings 1, are curved and shaped as
represented at Figure 3, so that narrow portions of their surfaces, having the
largest diameter, shall bear upon the inner curved surfaces of the coupling box j;
the rest of the outer surfaces of the said rings 1, being, by virtue of their shape not
in contact with the interior of the said box j.--The said rings 1, are rendered elastic
by being split on one side as shewn at o, and they are further of such length that
they are forced inwards when the bushes k, are screwed up, the inner ends of the
said bushes k, bearing upon and against the outer ends of the rings 7, which are
thereby forced into the hollows of the box j, until they become tightened with the
requisite degree of rigidity between the said box j, and the shaft m, and n. The
shafts m, and n, are represented at Figure 3, as of different diameters, but this form
of coupling may be constructed to couple shafts of corresponding diameters.
The improved couplings hereinbefore described and represented upon the
accompanying Drawings, besides being used for coupling rotating shafts, may
also be used for coupling non-rotating shafts whether solid or hollow, such as
tie bars or pipes or their analogues.
Having now described and particularly ascertaind the nature of our said
Invention and the system, mode or manner in or under which the same is or may
be used or practically carried in effect we would observe in conclusion that what
we consider to be novel and original and therefore claim as secured to us by the
herein before in part recited Letters Patent is :-
First The shaft couplings consisting of the hollow circular box a, having the
double conical hollow b, and c, formed therein, and screw threads d, box nuts e, and
semicircular wedges f, and their attachments all substantially as and for the
purposes herein before set forth with reference to Figures 1, and 2, of the
accompanying Drawings, or the mechanical equivalents of all or any of these
several parts.
Second-The shaft couplings consisting of the hollow circular box j, screw
threads d, screwed bushes k, and split rings l, and their attachments all

page_text: substantially as and for the purposes bereinbefore set forth with reference to
Figures 3, and 4, of the accompanying Drawings, or the mechanical equivalènts
of all or any of these several parts.
In Witness Whereof I, the said Charles Leonard on behalf of the said Thomas
Leonard Ellis and myself have hereunto set my hand and seal this Fifteenth
day of April in the year of our Lord One Thousand eight hundred and eighty-four.
CHARLES LEONARD
(1.9)