IMPROVEMENTS IN SHAFT-COUPLINGS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Louis Sterne at the Office of the
Commissioners of Patents on the 1st December 1883.
LOUIS STERNE, of Westminster, in the County of Middlesex Engineer,
"IMPROVEMENTS IN SHAFT-COUPLINGS
"
My Invention relates to flexible couplings for connecting lengths of machine
shafting, and is designed to obviate the inconvenience and difficulty caused by
connecting the ends of such shafting by the ordinary rigid couplings, when the
shafts are slightly out of axial alignment with each other.
According to my Invention I provide a coupling of this class which is simple in
construction but is at the same time effective and durable.
My said Invention consists in the novel construction and arrangement of parts
as hereinafter described.
In constructing my improved coupling I provide two discs of metal which are
adapted to be secured by keys, set screws, or other suitable means, to the adjacent
ends of the shafts to be coupled. Upon one face of each of these discs I arrange
a number of pins or studs which project forward, towards the face of the opposing
disc.
The number of pins on one disc, hereinafter termed the first disc; is equal to
the number of pins on the other disc, hereinafter termed the second disc I may use
any convenient number of these pins or studs according to the dimensions of the
coupling and other circumstances, but for ordinary purposes I prefer to place four
upon each disc.
The pins or studs on each disc are arranged equidistant from the centre of the
shaft to which they are connected and from each other, but the pins or studs upon
the first disc are at a greater distance from the centre of the latter than the pins
or studs upon the second disc.
An endless band, which is preferably such as is described in the specification of
former Letters Patent granted to me and dated 2nd June A.D. 1868 No. 1811,
but which may if desired be of india rubber, steel, leather, woven fabric, or any
other suitable material, is interlaced between the said pins or studs, that is to say,
it passes over a pin or stud on the first disc and under a pin or stud on the second
disc alternately, so that the pins on the latter are on the outer side of the band
and those on the former on the inner side thereof.

page_text: By this construction, if, say the second disc is on the shaft which is to transmit
motion to the other shaft, the said disc will be caused to rotate, and the first effect
of this movement will be to tighten the band which will then transmit motion to
the first disc and the shaft in connection therewith, the said band allowing, on
account of its flexibility, for any movement caused by the shafts being out of
alignment, and consequently permitting the said shaft to run freely without
wringing or grinding in the bearings.
The pins on the discs may be round, oval, or of other suitable shape in transverse
section, and if round, may be provided with rollers or loose sleeves to avoid any
rubbing action which might exist between the studs and the band.
"
In order to be able to disconnect one shaft from the other when required, I may
make the studs on one disc in the form of screw bolts the heads of which are on
the rear face of the disc, holes being tapped in the disc for the said bolts, so that
by unscrewing the said bolts the said studs may be moved in such a manner that
when the disc with which they are connected is rotated they will not come into
contact with the band. Or I may mount the studs of one disc on nuts to be
moved by screws arranged radially in the said disc in the same manner as the
dogs of a "universal chuck so that the said screws may be moved either
separately or simultaneously out of engagement with the band. The said screws
also serve the purpose of tightening the band in case it should become too loose.
If the screws are in the first disc the studs thereon will have to be moved inwardly
to clear the studs on the second disc; and if the screws are on the second disc the
studs will have to be moved outwards to clear the studs on the first disc; or I
may employ any other suitable arrangement for disconnecting the said discs
quickly and conveniently when desired.
In order to cover the interior of the coupling I arrange a flange to project from
one disc over the edge of the adjacent disc and form a cap.
To prevent the two parts of the coupling from becoming disconnected in case one
of the shafts to which it is connected has any excessive endwise movement I may
pass a bolt or bolts through the discs, the length of the said bolt or bolts being
sufficient to allow the discs to move freely but yet not to come apart; or I may
bolt, or otherwise secure, a flange onto the projecting edge of the cap on the one
disc, the said flange projecting behind the other disc.
According to a modification of this Invention I dispense with the pins on one
disc, and form, in place thereof, curved openings which are adapted to receive the
pins on the other disc. The curves of the said openings are not concentric with
the disc but are each arranged so that one end thereof is nearer the centre of the
disc that the other end. By reason of this arrangement it is not necessary that
the shafts should be in the same line (which would be the case with concentric
grooves) as, if the pins on, say the top of the disc, move in their openings towards
the centre of the disc, the pins on the bottom of the disc move away from the
said centre. In order to allow for any rocking motion between the two shafts
the edges of the said openings are curved transversely, or rounded.
Instead of interlacing one continuous band between all the pins or studs I may
pass a band around each pair of the said pins or studs.
It will be obvious that the pins or studs may be cast with the discs or may be
secured to the same as separate pieces.