Improvements in Shaft Couplings.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Shaft Couplings.
We, HENRY HERMAN WESTINGHOUSE, Mechanical Engineer, residing at
Franklin Street, in the Borough of Edgewood, County of Allegheny, State of
Pennsylvania, and United States of America, and WILLIAM ANDREW BOLE,
Mechanical Engineer, residing at No. 55 Howe Street, in the City of Pittsburgh,
County of Allegheny, State of Pennsylvania, and United States of America, 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:
Our improvements relate to shaft couplings of the flexible class or type, in which
provision is made for variation from axial alignment of the connected sections, and
an elastic application of driving power is effected. The object of our invention is
to provide a shaft coupling of such type having a greater capacity of flexibility
than heretofore, and in which the transmission of driving power will be divided
uniformly between the several elastic connecting members through which it is
imparted. To this end, our invention, generally stated, consists in the combination
of two coupling heads or frames, each adapted to be fixed upon an independent
shaft section, and a series of tangentially disposed springs, each coupled at one end
to one of the coupling heads, and at the opposite end to the other coupling head;
also in the combination with a shaft coupling as specified, of an insulating medium,
interposed between the main portion of one of the coupling heads and the members
connecting the same with the other coupling head. The improvements claimed are
hereinafter fully set forth.
In the accompanying drawings:
Figure 1 is an end view, in elevation, of a shaft coupling illustrating an
application of our invention;
Fig. 2, a view, partly in side elevation and partly in transverse section at the
line a, a, of Fig. 1;
Fig. 3, a transverse section at the line y, y, of Fig. 1, and;
Fig. 4, an end view, in elevation, illustrating a modification in the disposition of
the springs.
In the practice of our invention, referring to Figs. 1, 2, and 3, we provide two
coupling heads or frames, 1, 2, which are provided with central hubs, adapted,
respectively, to be secured upon the sections 3, 4, of shafting to be coupled
together. The main body of the head 1 is preferably, as shown, in the form of a
spoked wheel, to the spokes of which there is secured, concentrically, an annular
flanged supplemental section 1*, provided with a series of suitable coupling
connections, as, in the instances shown, pins or bolts 5, fitted, with their axes
substantially parallel to the axis of the head 1. The supplemental section 1° is
secured to the head 1, by bolts 6, direct contact of the connected members with
each other, and with the connecting bolts 6, being prevented by thimbles 7, of any
suitable insulating material, surrounding the bolts and provided with end flanges
which prevent contact of metal with metal, at the ends of the bolts.
The head 2, which is secured upon the shaft section 4, is in the form of a wheel
or disc, which is, similarly to the supplemental section 1° of the head 1, provided
with a series of coupling connections, said head 2 having, in the form herein shown.
peripheral lugs or bearings 8, in which are fitted a series of coupling pins or
bolts 9, corresponding in number with the pins 5 which are fitted in the supple-
mental section 1, of the head 1, and having, like the latter, their axes substantially
parallel with the axis of the head on which they are carried. The outer diameter
of the head 2, both over its lugs 8, and on its body, is sufficiently less than the inner

page_text: diameter of the body of the supplemental section 1" of the head 1, and the
diametrical distance between its lugs 5, to allow free lateral movement of the
heads 1 and 2, and the shaft sections to which they are secured, relatively one to
the other.
The heads 1 and 2 are so arranged that the coupling pins 5 of the former shall
alternate in position with the pins 9 of the latter, and the alternate pins are
connected one to another by. a series of helical springs 10, which are disposed
tangentially, that is to say, the axial line of each spring is substantially tangential
to a circle described about the centre of the coupling head to which one end of the
spring is coupled, and passing through the point of connection of the spring to said
head. The springs 10 are so coiled as to be capable of either extension or
compression, and one end of each spring is coupled to one of the bolts 5, and the
opposite end to one of the bolts 9. Each coupling pin of each head is therefore, as
shown in Fig. 1, connected, by oppositely extending springs, with the two adjacent
coupling pins of the other head. In the rotation of the coupled shaft sections in
either direction, either being the driving member, the driving power is imparted to
the other shaft section through the series of springs 10, and as two of these are
coupled to each of the pins 5 of the supplemental section 1" of the head 1, and two
to each of the pins 9 of the head 2, it will be seen that one half of the series of
springs will be under uniform tension and act to elastically transmit the driving
power to the driven section, while the other half of the series will be subject
uniformly to compression, and will so transmit the driving power, as well as, by
their clasticity, serve to cushion and reduce jars due to any inequalities or sudden
variations in power or resistance. By reason of the tangential disposition of the
several springs of the series, as hereinbefore specified, a greater range of variation
of alignment of the coupled shaft sections is admissible, without distortion or other
injury to the springs, than where, as in prior instances in the art, the shaft sections
are connected by springs whose common axial line is coincident with the normal
axial line of the shaft sections. It will further be seen that as each of the series
of coupling springs 10, is not opposed or restricted as to movement by any bearing
surface between its end connections, and there being free space provided between
each end connection and the opposite coupling head as before described, lateral
movement of the shaft sections, under variations of alignment, is fully provided for
and permitted.
The springs 10 are positively connected at their ends, to the pins 5 and 9, by
blocks 11, fitting truly thereon, so as to provide ample bearing surface. The
blocks 11 are provided with end stems 12, connected to the springs in any suitable
and convenient manner so as to be substantially integral with the springs, as by
blocks grooved externally to fit within the coils of the springs. As shown in
Figs. 2 and 3, one of the blocks 11 on each coupling pin, is divided, so as to
provide two bearings, fitting the pin on opposite sides of the bearing of the other
block thereon.
The modification illustrated in Fig. 4, differs from that before described, in the
particular that all of the series of springs are subject either to tension or to
compression (according to the direction of rotation of the coupled shaft sections, or
to the section which is employed as the driving member) in lieu of one-half the
series of springs being subject, in operation, to tension, and the other half to
compression, as in the previous instance. Each of the springs 10, is, in Fig. 4, as in
the previous instance, coupled at one end to a pin 5 of the section 1", and, at the
other, to a pin 9 of the head 2, but the pins of the respective heads are not, as
before, necessarily alternated in position, nor is each pin of one head coupled by
oppositely extending springs to two pins of the other head. It therefore results
that all the springs will transmit the driving power from one to the other shaft
section either under tension or under compression, accordingly as may be
determined by the direction of rotation or the selection of the driving member.
While we have specified pins or bolts as the preferred means for connecting the
springs to the coupling heads, deeming these to be most convenient and desirable

page_text: for the purpose, we do not desire to limit ourselves to such specific form of attach-
ment, as any other suitable means for connecting the springs alternately to one and
the other head, would similarly perform the same function and, in the operation of
the coupling, act as a mechanical equivalent for that shown.
It will be seen that under our invention as above described, a material range of
flexibility is afforded in the coupling, so as to admit of variations of alignment of
either or both of the coupled sections, without interfering with their rotation or
imparting injurious strain to the connecting members. Thus, the shafts may rotate
with a substantially uniform division of the transmission of driving power among
the several springs, either when in the normal condition of being in common axial
line, or when either or both shafts should be at an angle to the normal axial line,
or when both shafts should be in such position that their axial lines would fail to
meet.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. The combination, in a shaft coupling, of two coupling heads, fixed upon
independent shaft sections and wholly disengaged one from the other so as to have
a free range of relative lateral movement, and a series of tangentially disposed
springs, each coupled at one end to one head and at its opposite end to the other,
and being located in an annular space between the coupling heads which is of
greater transverse dimensions than the diameter of the springs, so as to have the
capacity of lateral movement with either or both coupling heads, substantially as
set forth.
2. The combination, in a shaft coupling, of two coupling heads, fixed upon
independent shaft sections and wholly disengaged one from the other, so as to have
a free range of lateral movement, a series of coupling pins fitted in each head, and a
series of tangentially disposed springs, each coupled at one end to a coupling pin of
one bead and at its opposite end to a coupling pin of the other, and being located
in an annular space between the coupling heads which is of greater transverse
dimensions than the diameter of the springs, so as to have the capacity of lateral
novement with either or both coupling heads, substantially as set forth.
3. The combination, in a shaft coupling, of two coupling heads, each adapted to
be fixed upon a shaft section, and a series of springs connecting said heads, one to
the other, each point of spring attachment upon either head being coupled, in
opposite directions, respectively, to two points on the other, substantially as set forth.
4. The combination, in a shaft coupling, of two coupling heads, each adapted to
be fixed upon a shaft section, a series of coupling pins fitted in each head, the pins
of one head being alternated in position, relatively to those of the other, and a
series of springs connecting a coupling pin of one head with the two adjacent
coupling pins of the other head, substantially as set forth.
5. The combination, in a shaft coupling, of two coupling heads, each adapted to
be secured upon a shaft section, one of said heads being divided into two sections,
an insulating medium interposed between said sections at their point of connection,
a series of coupling pins fitted in one of said sections, a series of coupling pins fitted
in the other head, and a series of springs, each coupling at one end to a coupling pin
of one head and at its opposite end to a coupling pin of the other, substantially as
set forth.
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Witnesses:
J. SNOWDEN BELL.
F. E. GAITHER.
HENRY HERMAN WESTINGHOUSE.
WILLIAM ANDREW BOLE.