Improvements in Couplings for Shafts, Bars, and the like.
Year: 1897

page_text: Date of Application 29th May, 1897.-Accepted 24th, July, 1897.
COMPLETE SPECIFICATION.
Improvements in Couplings for Shafts, Bars, and the like.
I, EMANUEL MULLER, of 11, Karl Heinestrasse, Leipzig-Plagwitz, Saxony, in the
Empire of Germany, Engineer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention has for its object a shaft and bar coupling which is especially
distinguished from all the couplings hitherto known by its requiring considerably
less dimensions in length and diameter and by its being capable of being made
considerably cheaper.
This improved coupling is shown in three forms of construction in the accompanying
drawings, the first for thin and the second for strong shafts or bars, whilst the third
form of construction is a coupling which allows of a mutual longitudinal adjustment
of the coupled parts.
Figure 1 shows the first form of construction of a part of the coupling in plan
view before the ends which are to be coupled or connected are pressed together;
Figure 2 is a plan view of the ends when pushed together, with the lower half of
the coupling ring and the safety ring laid round in cross section;
Figure 3, a vertical section of the two ends of the shaft coupled with one another
and the whole coupling displaced 90° to that of Figure 2; and
Figure 4, an end view in the direction of the arrow I of Figure 3 after removing
the upper coupling ring;
Figure 5 is a similar top view to Figure 1 but of the second form of construction
of the coupling;
Figure 6, a similar plan view to Figure 2 of the second form of construction;
Figure 7, a partial vertical section of the two ends of a shaft coupled in the second
manner, taken at 90° to the view of Figure 6; and
Figure 8 an end view in the direction of the arrow II Figure 7, after the upper
half of the coupling ring and the safety ring have been removed;
Figure 9 is a vertical longitudinal section of the third form of construction of the
coupling;
Figure 10, an end view seen in the direction of the arrow I, Figure 9;
Figure 11 is an elevation ;
Figure 12, an elevation with the compression rings and safety rings partially
broken away; and
Figure 13 is a vertical longitudinal section of the upper part of the coupling on
an enlarged scale.
For the purpose of employing this improved coupling, the ends of the shafts a
and b which are to be connected are provided by forging, upsetting, sweating on of a
ring, or the like, with a small flange a b¹ tapering outwardly on its inner shoulder.
Both contact surfaces of the shaft a and b have a notch or groove a² b² running
transversely through the shaft to receive a prismatic insertion piece or key d which,
when the two ends of the shafts a and b are pushed together, engages half and half
in each of the grooves a² and 62 and thereby prevents the shafts rotating one against
the other.
When the two ends of the shafts have been thus pushed with their flanges

page_text: together and the key inserted, a hollow ring in two or more parts forming a coupling
ringe is pushed from both sides over the flanges and over the key lying between them,
and a compression or safety ring f, Figures 2 and 3, is then driven over the ring e
whereupon the ends of the shafts are firmly connected with one another and secured
against axial and radial adjustinent to one another. In order that the ring f may
firmly press together the halves of the ring e in a radial direction and be firmly fixed
thereon, the outer surfaces of the halves of the ring e as well as the inner surfaces of
the ring are made slightly conical so that the compression ring f works as a
wedge.
The second form of construction of the coupling is similar in size and as a whole
to that just described, with the exception that the ends which are to be coupled are
prevented from making a mutual displacement, not by means of a diagonal wedge,
but by means of several grooves or notches h and i, Figure 5, running through the
flanges longitudinally to the shafts in which wedges g are placed.
Figure 7 shows a further completion of the coupling having for its object the
securing of the compression ring f, and consists of two hollow rings & divided into
two parts which are screwed with their flat sides on the faces of the coupling ring e
and with their cylindrical edge on the periphery of the safety ring f either resting on
the same or engaging over the same.
These rings have for their object to secure the ring f in its position under all
circumstances, and in the case of any splitting or bursting of the latter ring, which
can hardly or only extremely rarely take place, the ring will prevent broken pieces
from flying about. Of course such a ring may be employed with the form of
construction first described.
The halves of the coupling ring e may be made of suitable material. The pressure
ring f is preferably formed of a tough wrought iron. The keys or wedges & and gare
preferably made of steel. Delta metal (aluminium, brass with 3% of aluminium) or
the like.
The third form of construction of the coupling shown in Figures 9-13 is
produced by allowing one of the flanges 61 to engage over the other a¹ and then
drawing the compression ring f immediately over the flange b' and the key g. In
this manner a waved or corrugated coupling is obtained in which the coupled ends,
under variations of temperature and the like, may unimpededly adjust themselves
one against the other.
As already mentioned, in this method of coupling only one of the ends of the
shaft a which are to be coupled is provided with an ordinary flange a¹. The other
end of the shaft b on the contrary has a flange b' turned out like a socket in which
the flange a exactly fits and may thus be adjusted in the longitudinal direction of
the shaft. The grooves h and i, on the ends to be coupled coming together, do
not lie side by side as previously but above one another as is best shown in Figure 13.
The keys g which in this case also again engage in common in both grooves h
and i are secured against any adjustment in the longitudinal direction of the
shaft by means of insertion pieces g¹ which engage partly in the keys and partly in
the end b of the shaft; a radial movement of the wedges is prevented by two
compression rings f driven on the outer domed or roof shaped hollow flange b¹. Any
slipping apart or slipping off of the rings f from the flange 61 is prevented by the
rings (the ring lying to the left may be in one piece) which rings are fixed on the
end faces of the flange b¹. In this manner the end a may be unimpededly axially
adjusted in the flange whilst it is compulsorily connected in both directions of
rotation with the end b.
It is of course self evident that the wheels, or cord or belt pulleys in all these couplings
must either be divided or mounted on stronger parts of the shaft, or fixed on the
shaft by means of wedge sockets or bushes, while the smaller diameter of the ends
of the shafts allows of the use of closed (two armed) hanging bearings which is
impossible where disc couplings are used.
The advantages of this improved coupling are as follows:-
1. As keying up or unkeying of such coupling sockets is no longer necessary, as is

page_text: the case in the ordinary couplings, the loosening or refastening of the coupling may
take place in a more convenient and rapid manner.
2. In consequence of the strong friction between the flanges a¹ b¹ and the coupling
ring e, the wedges d and g are relieved, so that the torsion of one part of the shaft
does not require merely to be conveyed to the other portion of the shaft through
the said wedges, and surface pressure on these wedges is considerably diminished.
3. The dimensions (as already mentioned at the commencement of this specifica-
tion) in this improved coupling are very much smaller in comparison to other
couplings, and consequently the weight of the coupling is extremely moderate.
The small length of the improved coupling allows in many cases belt pulleys to
be employed in places where it would be impossible to do so where other couplings
were used.
4. The price of the improved coupling is considerably lower than that of other
couplings, even when the dearest material, such for instance as Delta metal, is
employed for the coupling rings.
5. The coupling has only a smooth outer form with no projecting parts, and
meets therefore all requirements as regards safety of working.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A coupling for shafts, bars and the like, characterised by a coupling ring
formed of two or more parts with slightly tapering periphery and with inwardly
projecting edges tapered at the inner sides and adapted to engage over similarly
tapered or bevelled flanges formed on the ends of the shafts or rods, so that by
means of a compression ring driven over the coupling ring, the parts of the latter
are firmly pressed against the flanges of the shafts and the latter are thus held
together, whilst by the insertion of a diagonal wedge in the ends of the shafts,
or if preferred several wedges in the flanges of the shafts, a rotation of the shafts
independent of one another is avoided, substantially as hereinbefore set forth.
2. A form of construction of the herein described coupling in which hollow
rings (k) are screwed against the sides of the coupling ring parts (e) and embrace
the compression ring (f) on both its sides and periphery and thus secures the
same therefore in its position, and in case of any splitting of the compression
ring, prevents any broken pieces from flying about, substantially as described.
3. A form of construction of the herein described coupling characterised by the
flange (b) of the one shaft end (b) being turned in the form of a socket and engaged
over the flange (a¹) of the other shaft end (a), whilst wedges (g) in the ends of the
shaft (b) are secured against longitudinal displacement by means of insertion
pieces (g), and against radial adjustment by compression rings (f) directly forced on
to the flange (b), with the object of allowing the coupled ends (a and b) a certain
longitudinal adjustment against one another, substantially as described.
COLL 1
1007