Improvements in Couplings for Shafts.
Year: 1891

page_text: Date of Application, 11th Mar., 1891
Complete Specification Lelt, 1st Dec., 1891-Accepted, 2nd Jan., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS & HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improvements in Couplings for Shafts.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, West-
minster, in the County of Middlesex, Electrical Engineers, do hereby declare the
nature of this invention to be as follows:-
This invention relates to a construction of couplings for shafts placel either in
line with or at an angle to each other, which couplings will also operate if the
shafts are out of line.
For this purpose, there is interposed between the two parts of the coupling
connected respectively to the contiguous ends of the two shafts, a third part
consisting of a bar or disc shaped body, which, in the case of parallel shafts, is
connected to the other two parts of the coupling by means of simple links acting
either by tension or thrust, the connections being effected by means of cylindrical
pins for parallel shafts, while for shafts placed at an angle, the said connections are
formed as universal joints.
According to one arrangement for this purpose, the parts of the coupling fixed
on the ends of the shaft consist of double ended cranks, between which is placed a
square frame to the four corners of which are fixed projecting pins, and each of
these pins is connected by a short link to a corresponding pin of one of the double
cranks, which are placed at right angles to each other, so that one pair of
opposite corners of the frame are connected by links to the two pins of the one
double crank, and the other pair of corners are connected to the pins of the other
crank.
Thus on rotary motion being imparted to the one shaft, it will drag round the
frame by means of its links, and this in its turn will push round the other shaft by
means of the other set of links, the first set of links being consequently put in
tension and the sides of the frame which transmit the strain to the other pair of
links being put in compression while the other set of links and sides of the frame
will respectively be put in compression and tension.
Should the first named shaft have its motion reversed, the strains on the parts of
the coupling would also be reversed.
If the two shafts are parallel but out of line with each other, so that the pins of
the two double cranks describe two excentric circles, the links connecting them
with the respective corners of the frame will during each revolution turn upon
their connecting pins so as to adjust themselves to the varying relative positions of
the e pins due to the excentricity of the shafts.
In the above described construction the said square frame can be replaced by a
ring shaped or cross shaped frame, the construction and action being otherwise the
same as above described.
According to another modification the intermediate part of the coupling is
formed as a simple bar, having two pins at each end, one of which is connected by
a link to the one crank pin of the one shaft, while the other is connected by a link
to the diametrically opposite crank pin of the other shaft, the two double cranks
being in this arrangement situated in the same plane, while the intermediate
With this arrangement the
connecting bar is placed at right angles thereto.
connecting links may either all be subject to a tension or to a compression strain,
according as the driving shaft revolves in the one direction or the other.
links are in tension the intermediate connecting bar is m compression, and rice versa.
With this arrangement the two shafts can also be placed out of line with each
If the

page_text: other, the angular position of the several connecting links being made to shift
continually during a revolution as described with the first arrangement.
Either of the above constructions can be employed with shafts placed at an angle
to each other, by employing universal joints for the connections of the links, as
already stated.
1 1001
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Couplings for Shafts.
We, SIEMENS BROTHERS & CO. LIMITED, of 12, Queen Anne's Gate, West-
minster, in the County of Middlesex, Electrical Engineers, 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 relates to a construction of couplings for shafts placed either in
line with or at an angle to each other, which couplings will also operate if the shafts
are out of line.
For this purpose, there is interposed between the two parts of the coupling
connected respectively to the contiguous ends of the two shafts, a third part con-
sisting of a bar or disc-shaped body, which, in the case of parallel shafts, is
connected to the other two parts of the coupling by means of simple links acting
either by tension or thrust, the connections being effected by means of cylindrical
pins for parallel shafts, while for shafts placed at an angle, the said connections are
formed as universal joints.
The accompanying drawing shews by way of example various constructions of
the said improved coupling.
Figs. 11, 22, and 3 3, shew three actual constinctions while the other figures
are diagrams shewing the action of those constructions.
In the construction shewn respectively in front and side view at Figs. 1 and 14,
a square frame el is placed between the two double ended cranks fixed on the
contiguous ends of two shafts a a¹ arranged in line with each other.
The pins of the cranks are connected by links d to pins b fixed to the corners of
the frame e', the opposite corners of the frame being thus connected to the opposite
ends of the same crank.
Thus if the one shaft be rotated to the right hand, Fig. 1B, the other shaft a
will be forced to follow it by reason of its connection thereto through e' f' and d d²,
the rods d d being in this case subject to tension, while the rods d' d' are subject to
compression. In like manner, the parts of the frame situated between its
connections with double crank and the connections, which are behind them in
the direction of motion, with cranks will be subject to tension, while the parts of
the frame in front of them will be subject to compression, this being indicated
respectively by single and by double lines at. Fig. 1. Fig. 1 shews how the parts
are acted upon on the shaft a being rotated to the left hand.
Fig. 1 shews the shifted positions of the connecting links d when the shafts a a¹
are shifted out of line with each other. Thus if for example, the shaft a is shifted
into the position a°, the links d d connected to its double crank will assume the
positions do do.
If on the other hand the shaft a be shifted into the position a*,
the same connecting links will assume the positions d* d*. If the shaft a¹ be
shifted into the position a°, or a*, the links d, connected to the double crank fi
will assume the positions do, or d. Thus when the pins of the double crank f
describe a circle round a* excentric to a, the links d connected thereto will vibrate
from the position shewn in full lines both inwards and outwards, the dotted
positions dod indicating the extreme positions of such oscillation. The same
holds good for the other positions of the shafts.
1

page_text: In the arrangement shewn at Fig. 2. to 2º, the square frame e' is replaced by a
cross. The connections of the links however assume precisely the same positions
relatively to each other and to the cranks and shafts as in the former case.
The construction shewn at Figs. 3 to 3º differs from the foregoing in that the
two double cranks ff, instead of being at an angle to each other, are opposite
each other, and have their pins connected by links d to pins 6 on the opposite ends
of a bar so that such two pins serve simultaneously as the connections for both
sets of links and consequently two of the pins b of the previous constructions are
dispensed with, permitting of the substitution of a simple bar for the square
frame e or cross e².
With such a construction either all the connecting links d can be subject to
tension, and the bar to compression as indicated at 3B, or all the links can be
subject to compression, and the bar to tension, according to the direction of
rotation.
If the shafts are shifted relatively to each other, such for instance as a to the
position a*, and a¹ to the position ax Fig. 3º, then the left hand connecting link d
connected to the upper end of e³ will vibrate outwards to the dotted position (*,
and the right hand lower one will vibrate inwards to the position d*. The double
crank will consequently be shifted nearly parallel to itself into the position f* f*.
The double crank will in a similar manner, assume the position *, ƒ*, in
moving respectively inwards and outwards with the links a¹ as these assume the
positions. When the shafts a a¹ are shifted to the positions a° a° on the
opposite side of the bar e³, the links d d will vibrate into positions d° d°1
the opposite to those which they previously occupied, while the double cranks will
assume the positions f°, f°1.
1
From this it will be seen that the shafts a a' can be shifted into any positions
relatively to each other without preventing the proper action of the connecting
links dd' in case they are made of flexible material.
In either of the above described constructions if the shafts, in addition to being
shifted out of line, are also required to assume an angular position relatively to
each other, this can be provided for by simply making the connections of the links
with the cranks and intermediate frame or bar, as spherical or universal joints
instead of as cylindrical pins.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. A coupling for the contignons ends of parallel shafts consisting of a double
crank fixed on the end of each shaft, between which, is a disc, ring, bar or other
shaped body having pins connected by links to the pins of the double cranks in such
manner that the rotation of the one shaft will effect the rotation of the other shaft
through the links and intermediate body, even when the shafts are not in line with
each other substantially as described.
2. In a coupling such as is referred to in the preceding claim, constructing the
connections of the links with the cranks and intermediate body as spherical or
universal joints, so as to permit of the shafts assuming an angular position
relatively to each other, substantially as described.
Dated this 27th day of November 1891.
ABEL & IMRAY,
Agents for the Applicants.