IMPROVEMENTS IN COUPLINGS for DRIVING SHAFTS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE FOR OTHER PURPOSES
Year: 1876

page_text: LETTERS PATENT to Michael Heinrich Kernaul, of Berlin, Prussia, in the
Empire of Germany, for the Invention of "IMPROVEMENTS IN COUPLINGS for
DRIVING SHAFTS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE FOR OTHER
PURPOSES."
Scaled the 21st December 1876, and dated the 28th June 1876.
PROVISIONAL SPECIFICATION left by the said Michael Heinrich Kernaul
at the Office of the Commissioners of Patents on the 28th June 1876.
MICHAEL HEINRICH KERNAUL, of Berlin, Prussia, in the Empire of Germany.
"IMPROVEMENTS IN COUPLINGS FOR DRIVING SHAFTS, WHICH IMPROVEMENTS ARE
ALSO APPLICABLE FOR OTHER PURPOSES."
This Invention has for its object improvements in couplings for driving shafts,
which improvements are also applicable to other purposes.
To carry out my Invention I proceed in the following manner:-I couple two
shafts together in a suitable coupling box, by means of two arched wedges, in such
a manner that the wedges are placed in two hollows exactly suiting to their shape.
Such hollows are made in the periphery of the mouth of the coupling box in such
a manner that on turning the shafts from left to right the wedges are driven
forward in an eccentric direction, and the greater the resistance to be overcome by
the rotation the more firmly the wedges will be secured. The two bollows for the
wedges are so made that the deepest point of one hollow is in a line with the
highest point of the other hollow, so that the two wedges work in opposite direc-
tions. The hollows are a little broader than the wedges themselves, whereby even
when driving at the highest speed sufficient space remains to provide for the wear
of the wedges. The wedges are held in position by means of two screws, which it
is only necessary to slightly draw on by a screw-driver after first inserting the wedges
themselves into their respective hollows. By this means the wedges are so strongly
secured that the coupled parts are almost equivalent to a single piece, as too great
a degree of resistance against the rotatory motion would result in destroying the
coupling box, or even tearing off the shaft itself rather than releasing the coupling.
At the same time the screws prevent all risk of the wedges becoming disengaged
by any occasional inverse rotation of the shaft.
In order to facilitate the forming the hollows for the wedges before described I
make the coupling box itself somewhat wider in the middle, by doing which a
vacant space is produced.

page_text: My improved system of couplings is also adapted for use for the coupling of
pulleys, the only difference being that when applied to this purpose it is only
necessary to employ one wedge instead of two, as before described. The wedges are
made of steel and hardened, their interior surface being left rough in order that the
friction of the shaft against such inner surface may give it a tendency to move
forward and tighten up the wedge.
In order to separate the coupled parts of driving shafts it is only necessary to
simultaneously turn the two shafts in opposite directions after having first drawn
back the screws which hold the wedges in position, and to separate the coupled
parts of a pulley it is only necessary to draw back the screw which fastens the
wedge and then give it a slight blow in the direction in which the wedge points.
The advantages of my improved couplings, compared with those hitherto in use,
are as follows:-
1st. The dangerous nose wedges now frequently used are entirely dispensed with,
as the projecting nose (which is for the purpose of driving in the wedge) has the
disadvantage of being very liable to catch in and carry along with it loose leather
belts, and even the garments of the workmen, which thus frequently leads to
serious accidents, whereas by my improved system all such risk is completely
avoided, as the shafts, together with the parts fixed thereon, present only perfectly
smooth round surfaces.
2nd. It requires but little time to make the coupling, as the pieces are easily put
together and fastened, as before described, by means of the screws without requiring
the use of a hammer, whereas in employing nose wedges much time is required
for the exact centering of the shafts or the pieces fixed thereon, and frequently all
the parts are seriously damaged by the use of the hammer.
3rd. By my system the shafts remain perfectly round, as there are neither
wedge planes nor spring grooves, whilst by the other systems the parts are ren-
dered unfit by planes and grooves and scratches of the screws, these scratches also
rendering it difficult to put on the leather belts.
4th. By my improved system an accidental loosening of the coupling is rendered
impossible, although it frequently happens by the systems hitherto in use, as well
with shafts as with pulleys and fly and cog wheels.
5th. Hitherto great difficulty has been experienced in centering the various
parts on the shaft, more particularly those of larger diameter, but by my improved
system all the parts on the shafts are at once correctly placed in central position.
6th. Another great advantage attendant upon my improved system is the having
the coupled parts exactly centred, whereby a considerable amount of friction is
avoided, thereby effecting a considerable economy in the amount of fuel consumed.
My improved coupling is equally applicable to all the various parts of machinery
which have to be fixed on shafts, and its use is in every case attended with similar
advantages.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Michael Heinrich Kernaul in the Great Seal Patent Office on the 28th
December 1876.
$6
MICHAEL HEINRICH KERNAUL, of. Berlin, Prussia, in the Empire of Germany.
IMPROVEMENTS IN COUPLINGS FOR DRIVING SHAFTS, WHICH IMPROVEMENTS ARE
ALSO APPLICABLE FOR OTHER PURPOSES."
This Invention has for its object improvements in couplings for driving shafts,
which improvements are also applicable to other purposes, and in order that such
Invention may be more fully understood and readily carried into effect, I will now,
with the aid of the accompanying Drawings, upon which similar letters of reference
indicate corresponding parts, proceed more particularly to describe the nature and
operation of the same.

page_text: I proceed in the following manner :-I couple two shafts (A, B, Figure 1) together
in a suitable coupling box C by means of two arched wedges D and E in such a
manner that the wedges are placed in two hollows formed in the coupling box
exactly suiting to their shape. Such hollows are made in the periphery of the
mouth of the coupling box in such a manner that on turning the shafts from left
to right, as shown by the arrow a, b, Figure 2, the wedges are driven forward in
an occentric direction, and the greater the resistance to be overcome by the rotation
the more firmly the wedges will be secured. The two hollows for the wedges are
so made that the deepest point of one hollow is in a line with the highest point
of the other hollow, so that the two wedges work in opposite directions. The
hollows are a little broader than the wedges themselves, whereby even when
driving at the highest speed sufficient space remains to provide for the wear of
the wedges. The wedges are held in position by means of two screws shewn
at F, G, Figure 2, which it is only necessary to slightly draw on by a screw-driver
after first inserting the wedges themselves into their respective hollows. By this
means the wedges are so strongly secured that the coupled parts are almost
equivalent to a single piece, as too great a degree of resistance against the rotatory
motion would result in destroying the coupling box or even tearing off the shaft
itself rather than releasing the coupling. At the same time the two screws F
and G prevent all risk of the wedges becoming disengaged by any occasional
inverse rotation of the shaft.
In order to facilitate the forming the hollows for the wedges before described 1
make the coupling box itself somewhat wider in the middle, by doing which a
vacant space, shewn at H, Figure 1, is produced.
My improved system of couplings is also adapted for use for the coupling of
pulleys, as is illustrated and shewn at Figures 3 and 4 of the accompanying
Drawings, the only difference being that when applied to this purpose it is only
necessary to employ one wedge (instead of two, as before described), as shown in
Figure 4. The wedges are made of steel and hardened, their interior surface being
left rough in order that the friction of the shaft against such inner surface may
give it a tendency to move forward and tighten up the wedge.
In order to separate the coupled parts of driving shafts when my improved
coupling is employed, it is only necessary to simultaneously turn the two shafts
in opposite directions after having first drawn back the screws F and G which
hold the wedges in position, and to separate the coupled parts of a pulley when
my improved coupling is employed, it is only necessary to draw back the screw
which fastens the wedge and then give it a slight blow in the direction in which
the wedge points.
Figure 5 shews the wedge independently.
The advantages of my improved couplings, compared with those hitherto in use,
are as follows:-
1st. The dangerous nose wedges now frequently used are entirely dispensed
with, as the projecting nose (which is for the purpose of driving in the wedge)
has the disadvantage of being very liable to catch in and carry along with it
loose leather belts, and even the garments of the workmen, which thus frequently
leads to serious accidents, whereas by my improved system all such risk is completely
avoided, as the shafts, together with the parts fixed thereon, present only perfectly
smooth round surfaces.
2nd. It requires but little time to make the coupling, as the pieces are easily
put together and fastened, as before described, by means of the screws without
requiring the use of a hammer, whereas in employing nose wedges much time is
required for the exact centreing of the shafts or the pieces fixed thereon, and
frequently all the parts are seriously damaged by the use of the hammer.
3rd. By my improved system the shafts remain perfectly round, as there are
neither wedge planes nor spring grooves, whilst by the other systems the parts
are rendered unfit by planes and grooves and scratches of the screws, these
scratches also rendering it difficult to put on the leather belts.

page_text: 4th. By my improved system an accidental loosening of the coupling is rendered
impossible, although it frequently happens by the systems hitherto in use, as well
with shafts as with pulleys and fly and cog wheels.
5th. Hitherto great difficulty has been experienced in centreing the various
parts on the shaft, more particularly those of larger diameter, but by my improved
system all the parts on the shafts are at once correctly placed in central position.
6th. Another great advantage attendant upon my improved system is the having
the coupled parts exactly centred, whereby a considerable amount of friction is
avoided, thereby effecting a considerable economy in the amount of fuel consumed.
My improved coupling is equally applicable to all the various parts of machinery
which have to be fixed on shafts, and its use is in every case attended with similar
advantages.
Having thus particularly described and ascertained the nature of my said
Invention, and the manner of carrying the same into effect, I would have it under-
stood that I claim the improved method of coupling driving shafts or pulleys
and other machinery together, as herein-before described and illustrated by the
accompanying Drawings.
In witness whereof, I, the said Michael Heinrich Kernaul, have hereunto set
my hand and seal, this Twenty-eighth day of December, in the year of our
Lord One thousand eight hundred and seventy-six.
M. H. KERNAUL
(L.S.)