AN IMPROVED METHOD AND APPARATUS FOR COUPLING SHAFTS AND SECURING WHEELS OR THE THEREON " LIKE
Year: 1883

page_text: LETTERS PATENT to John James Purnell of Commercial Road Lambeth in the
County of Surrey for an Invention of
" AN IMPROVED METHOD AND
APPARATUS FOR COUPLING SHAFTS AND SECURING WHEELS OR THE
THEREON
"
LIKE
PROVISIONAL SPECIFICATION left by the said John James Purnell at the
Office of the Commissioners of Patents on the 5th February 1883.
JOHN JAMES PURNELL of Commercial Road Lambeth in the County of Surrey,
"AN IMPROVED METHOD AND APPARATUS FOR COUPLING SHAFTS AND SECURING
WHEELS OR THE LIKE THEREON
"
My invention relates to means of coupling cylindrical shafts together and of
securing thereon wheels, pullies or other pieces of mechanism. I will describe first
the construction which I employ for coupling two shafts together. I provide a
sleeve to fit,or nearly fit the ends of the two shafts and I divide this sleeve by a
single longitudinal slit so that it can be sprung to a little smaller or larger diameter.
Each end of of the sleeve is tapered externally and beyond each of the tapered
parts, towards the middle of the sleeve are three lugs or segments of flange
projecting outwards which have their sides presented towards the middle of the
sleeve made with a helical slope. I provide two sockets each having a hole
tapered to correspond with the taper of the sleeve, and having in front of the hole,
three lugs or segments of flange, projecting inwards from the shell of the socket,
these lugs having their inner sides made with a helical slope corresponding to that
of the lugs on the sleeve. For coupling two shafts together, I pass on to each
shaft one of the sockets and bring the ends of the shafts together with the sleeve
on them extending partly along each. I then advance the sockets till their lugs pass
through the spaces between the lugs of the sleeve and, turning the sockets partly
round, their lugs engage behind the lugs of the sleeve with a screw like action
which causes the sockets to be drawn tightly on to the tapered ends of the sleeve,
compressing the sleeve so that it takes a firm grip of the shafts.
The sleeve instead of being made in one piece, slit along its length may be made

page_text: in three or more segments, and instead of three sets of lugs on the sleeve and
sockets, two such lugs or a number greater than three may be employed
I employ a similar construction for fixing on a cylindrical shaft, a wheel pulley
or other piece of mechanism, that is to say, I divide the boss that has to be fixed
on the shaft with a longitudinal slit and I make it with taper ends and inclined 5
lugs such as I have described for the coupling, securing it in like manner by
sockets taking on to the inclined lugs and embracing the tapered parts of the boss,
so as to compress it firmly on the shaft.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John James Purnell in the Great Seal Patent Office on the
25th July 1883.
JOHN JAMES PURNELL of Commercial Road Lambeth in the county of Surrey
"AN IMPROVED METHOD AND APPARATUS FOR COUPLING SHAFTS AND SECURING
WHEELS OR THE LIKE THEREON
"
My invention relates to means of coupling cylindrical shafts together, and of
sccuring thereon wheels, pullies or other pieces of mechanism. I will describe first
the construction which I employ for coupling two shafts together. I provide a
sleeve to fit or nearly fit the ends of the two shafts and I divide this sleeve by a
single longitudinal slit so that it can be sprung to a little smaller or larger diameter.
Each end of the sleeve is tapered externally, and beyond each of the tapered parts,
towards the middle of the sleeve are three lugs or segments of flange projecting
outwards, which have their sides presented towards the middle of the sleeve made
with a helical slope. I provide two sockets, each having a hole tapered to corre-
spond with the taper of the sleeve, and having in front of the hole three lugs or
segments of flange, projecting inwards from the shell of the socket, these lugs
having their inner sides made with a helical slope corresponding to that of the lugs
on the sleeve. For coupling two shafts together, I pass on to each shaft one of the
sockets and bring the ends of the shafts together with the sleeve on them extending
partly along each. I then advance the sockets till their lugs pass through the
spaces between the lugs of the sleeve, and, turning the sockets partly-round, their
lugs engage behind the lugs of the sleeve with a screw like action which causes the
sockets to be drawn tightly on to the tapered ends of the sleeve, compressing the
sleeve so that it takes a firm grip of the shafts.
A is
Fig. 1 is a longitudinal section of this coupling, Fig. 2 is an end view, Fig. 3 is a
side view with one socket on and the other off, and shewn in section at fig. 4.
the sleeve split along a, at each end tapered and provided with the helical lugs B,
of which there may be three, as shewn, or two, or more than three. CC are the
sockets having corresponding helical lugs D. Holes E are provided in the socket
and in the collar of the sleeve for insertion of a bar to act as a wrench or spanner.
The sleeve, instead of being made in one piece, slit along its length, may be made

page_text: in three segments, as shewn at fig. 5, or in another number of seginents. I employ
a similar construction for fixing on a cylindrical shaft a wheel, pulley or other piece
of mechanism, as shewn by fig. 6 which is a section of a pulley and fig. 7 which is
an elevation of the sleeve. The sleeve A split along a, has on it the helical lugs B
which, on introducing A into the hole of the boss C, and turning it partly round,
engage with corresponding helical lugs D formed within the boss, causing A to
advance and to wedge itself tight in the boss and on the shaft, so that the pulley is
firmly held on the shaft.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim :-
First Coupling together cylindrical shafts by means of a split or divided taper
ended sleeve with helical external lugs, in combination with a pair of sockets
having corresponding internal lugs, substantially as herein described with reference
to figs. 1, 2, 3, 4 and 5.
Second Securing on a shaft a pulley, wheel or other piece of mechanism, by
means of a split taper ended sleeve with helical external lugs engaging with
corresponding internal lugs, substantially as herein described with reference to
figs 6 and 7.
In Witness whereof I the said John James Purnell have hereunto set my hand
and seal this Twenty fourth day of July in the year of our Lord, one thousand
eight hundred and eighty-three
JJ PURNELL (L.S.)