Improvements in Friction Couplings and Clutches for Connecting Shafting or for Connecting Pulleys to Shafts.
Year: 1891

page_text: Date of Application, 2nd Dec., 1891
Complete Specification Left, 2nd Sept., 1892-Accepted, 2nd Dec., 1892
PROVISIONAL SPECIFICATION.
Improvements in Friction Couplings and Clutches for Connecting
Shafting or for Connecting Pulleys to Shafts.
GEORGE POWELL WALKER Engineer 62 Blackfriars Road London S.E. do
hereby declare the nature of this invention to be as follows:-
First. A muff or sleeve, preferably of cast iron, to receive one end of each of
two shafts to be connected. The muff is connected to the shafts by two straps of
wrought iron or other suitable material. The straps are placed round the shafts,
on which they are tightened by means of bolts or screws which draw the ends of
each strap together. Care is to be taken that the straps are not made of so great
a thickness as to destroy their spring and flexibility and convert them into com-
paratively rigid clamps. Each strap, thus fixed by friction on the shafts, is
connected to the muff by means of a pin or key on each strap, which fits into a
corresponding recess in the muff, thus connecting the two shafts.
Second. Two separate castings of suitable form are fixed, one on each of the
contiguous ends of the shafts to be connected, by keys or with straps as above
described. The one casting carries a ring which fits into the other. This ring is
divided at one place, and one end of the ring is connected to the casting first
mentioned, and the other end is connected by links or suitable mechanism to a
controlling lever by means of which it may be caused to expand in the ring into
which it fits, thus forming a frictional connection between the two castings.
My invention in this arrangement is particularly-Fixing one end of the ring
and expanding the other, in place of fixing the ring in the centre and expanding
the two free ends as is usually done.
These clutches are applicable for connecting pulleys to shafts.
-
GEO. P. WALKER.
COMPLETE SPECIFICATION.
Improvements in Friction Couplings and Clutches for Connecting
Shafting or for Connecting Pulleys to Shafts.
GEORGE POWELL WALKER, of 62 Blackfriars Road, in the County of Surrey,
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 :-
My invention relates to improvements in friction couplings and clutches for
connecting shafting or for connecting pulleys to shafts.
The main object of my said invention is to provide a shaft-coupling, whereby
shafts of the same, or of different diameters, can be efficiently connected without
affecting the alignment of the said shafts, and which will offer great resistance to
torsion and also to drooping of the shafting at the joints.
For this purpose, I so construct my improved shaft-coupling that the parts
thereof which grip the shafts, are separate from the part thereof whereby the
ends of the shafts are kept in true alignment, and through which motion is trans-
mitted from one shaft to the other, the several parts of the coupling being suitably
connected to permit such transmission of motion.
My improved coupling comprises a muff or sleeve, preferably of cast iron, and
formed to receive one end of each of two shafts to be connected.
This muff or sleeve is connected to the shafts by two straps, made of wrought
DQ11

page_text: iron or of other suitable material, which will afford the requisite flexibility, which
straps are inserted in the said muff or sleeve and, after the shafts have been
inserted in them, are tightened upon the said shafts by means of bolts or screws,
which draw the ends of each strap together: It is important that the straps
should not be made of so great a thickness as to destroy their spring and flexibility
and convert them into comparatively rigid clamps. Each strap, thus fixed by
friction on the shafts, is connected to the aforesaid muff or sleeve by means of a
pin or key on each strap, which fits into a corresponding hole or recess in the
muff thus connecting the two shafts so that motion may be communicated from
one to the other.
a
In securing a pulley to its shaft according to my said invention I employ
strap which is fixed upon the shaft and which is provided with a pin or projection
to enter a hole or recess in a sleeve or boss in the centre of a pulley.
In making a friction clutch according to my said invention for connecting two
shafts, I employ two separate castings of suitable form which are fixed one on each
of the contiguous ends of the shafts to be connected by keys or with straps as
above described. The one casting carries a ring which fits into a ring carried by
the other. This ring is fixed at one end to the casting first mentioned and is split
or divided close to the end at which it is fixed, suitable mechanism is provided and.
connected by links, or a suitable device, to a controlling lever, by means of which
the split ring may be caused to expand in the ring into which it fits, thus causing
a frictional connection between the two castings. When the said clutch is to be
used for the purpose of connecting a pulley to a shaft, I employ a suitable casting
which carries a ring split or divided at one point and adapted to fit into a ring
carried by the pulley, the split ring being fixed at one end to the said casting..
This casting is fixed on its shaft by keys or with straps as above described.
The important feature in this arrangement is fixing one end of the split ring and.
expanding the other, in place of fixing the split ring at a point diametrically
opposite the split and expanding both ends as is usually done.
With my improved arrangement, it is necessary that the direction of turning
should be from the fixed end of the split ring towards the free end thereof, the
friction itself, between the two rings, then causes the split ring to expand and this
action continues throughout the whole circumference of the split ring, in place of
only half the circumference thereof as is the case with the split rings fixed in the
usual manner.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a longitudinal central section of one form of my improved shaft-
coupling, one of the straps being shown in side elevation.
Figure 2 is a transverse section on the line a, e, Figure 1, the strap being shown
in elevation.
: Figure 3 is a side elevation, and
Figure 4 an end elevation of the said coupling.
Figure 5 is a side elevation, and
Figure 6 an end elevation, partly in transverse section, showing one of the
straps employed in the said coupling and the screw-bolt for securing it upon the
shaft.
Figure 7 is a longitudinal central section, of another form or modification of my
improved coupling, one of the straps being shown in side elevation.
Figure 8 is a transverse section on the line ', ', Figure 7, the strap being shown
in elevation.
Figure 9 is a side elevation, and
Figure 10 an end elevation of the coupling shown in Figures 7 8. and 9.
Figure 11 is a side elevation, and
Figure 12 an end elevation, partly in transverse section, showing one of the
straps used in such coupling and the means for securing the said strap to the

page_text: Figure 13 is a longitudinal central section, and
Figure 14 a transverse section on the line ²,, Figure 13, illustrating one form
of friction-clutch constructed according to my said invention for securing a pulley
to a shaft.
Figure 15 is a view of the interior of one half of the boss of the said pulley.
Figure 16 is a longitudinal central section, and
Figure 17 an end elevation illustrating a form of friction-clutch, constructed
according to my said invention for securing a pulley on a shaft.
Figures 18 to 25 are different views illustrating details of construction of the
said clutch.
Referring to Figures 1 to 12, a is the muff or sleeve, b, are the straps and
c, care screw-bolts for securing the said straps to the shafts.
In the form or modification of my invention illustrated in Figures 1 to 6, the
muff or sleeve a is provided with openings a¹ which are of such size and shape as
to permit the introduction of the straps through the same into the spaces provided
for them in the interior of the said muff or sleeve, before the said muff or sleeve is
placed upon either shaft; in this form or modification, the said openings also
serve to admit a suitable key or spanner for turning the screw-bolts c. The muff
or sleeve a is also provided with holes a², preferably cylindrical, into which enter
pins, keys or projections formed on the exterior of the straps b. By means of
the straps and their pius, keys or projections the shafts A, A1 are connected
with the muff or sleeve a so that motion will be communicated through the said
muff or sleeve a, from one shaft to the other.
In the form or modification of my invention shown in Figures 7 to 12, 1 dispense
with the pins or projections & on the straps b, and employ the screw-bolts c as the
means for connecting the said straps with the muff or sleeve u. Depressions or
recesses a³ are formed in the exterior of the muff or sleeve a to allow the square
heads c and nuts 2 of the bolts e to be conveniently manipulated and at the same
time kept within the circumference of the said muff or sleeve as any projections
would be a source of danger.
It will be seen that, in both of the above described forms of my improved
coupling, the muff or sleeve a has three surfaces u for supporting the shafts A, A',
the ends of which are thus brought into true alignment with each other.
The construction of the muff or sleeve in this manner, moreover, effectually
prevents drooping of the shafting at the joints. The whole of the outside of the
coupling being free from projections, may be turned and polished if desired.
A great advantage of my improved coupling is that, owing to the employment
of two separate flexible straps, each of which may be clamped on its particular
shaft quite independently of the other, the said coupling is capable of being
used to connect two shafts whether they are of the same or of slightly different
diameter, without affecting the alignment of the said shafts. Whereas when a
single rigid clamp is used to connect two shafts of slightly different diameter, it
obviously cannot be made to grip both perfectly; and even with a clamp made
with one half split or divided and the other half rigid, although the independent
gripping could be effected, the shafts if of different diameter would be thrown out
of line with each other by the tightening of the clamp upon the same.
Another advantage is the flexibility of my improved straps. owing to their
comparatively narrow width and small thickness, and to their being manufactured
of wrought iron or other malleable metal.
Figures 13, 14, and 15 illustrate the adaptation of my invention for fixing a
pulley on, or connecting it with a shaft, the boss a of the pulley B taking the place
of the muff or sleeve above described. The pulley shown in these figures is what
is known as a split pulley, being split diametrically through the rim and boss, so
that there is no necessity to provide an opening in the boss a through which to pass
the strap ; an opening as is, however, provided for the admission of a key or
spanner for adjusting the screw-bolt c. A hole a is, moreover, drilled or cast in
the boss a for the reception of the pin or projection formed on the strap b, for

page_text: the purpose of connecting the said strap with the sleeve or boss a, so that motion
will be communicated through the said sleeve or boss a and strap from the
pulley B to the shaft A. The strap is secured on the shaft A by means of a
screw-bolt c as herein before described.
In Figures 16 to 25, I have shown a form of my improved friction-clutch for
connecting a pulley with a shaft. The upper half of Figure 16 is a section on
the line X, X, Figure 19, and the lower half of Figure 16 is a section on the
line Y, Y, Figure 19. The said clutch consists of an outer cylindrical casing a,
secured to or cast in one piece with the pulley, and bored or turned internally to
receive an externally turned ring b, which ring is split at a point of its circumference
in the line X, X, and is fixed at a point in the line Y, Y, to a flanged collar d,
keyed or otherwise firmly secured to the shaft A, by means of a bolt e passing
through the flange and through the ring b, the said ring being thickened where
the bolt e passes through it as is shown at in Figures 16, 18 and 19; a nut e¹
serves to tighten and secure the bolt e in position. A lever e is pivoted upon a pin c¹
secured in lugs d' formed on the flanged collar d, this lever is shown separately in
Figures 22 and 23, and the flanged collar d is shown in Figures 24 and 25. The
outer or free end of the lever c, is provided with a screw c² fitting into a screw-
threaded hole in the said lever, and locked in any desired position therein by means
of a lock-nute; this screw is provided with a square head e to facilitate its
adjustment, which head bears on the conical part 1 of a collar of fitted to slide
longitudinally on the shaft A. A wedge-shaped piece g, which is shown detached
in Figures 20 and 21, is fitted between the ends 62 of the split ring b, and is
arranged to be forced into the space between the said ends by means of the said
lever c.
When it is desired to put the clutch "into gear," that is to say, to cause
the shaft to drive the pulley or vice versa, the collar f is moved along the shaft A
towards the flanged collar d by means of a lever or equivalent device, so that its
conical part moves the screw c², and consequently the lever c, outwards in a
radial direction from the axis of the said shaft. The wedge-shaped piece is by
this outward motion of the lever c, forced between the inclined ends 2 of the split
ring b, thus causing the said ring to expand and bear against the internal surface of
the cylindrical casing a, with sufficient friction to ensure the transmission of motion
from the pulley to the shaft or vice versa. To release or disengage the clutch it is
only necessary to withdraw the collar for move the same away from the collar d.
My improved friction-clutch is also capable of being used to connect two shafts.
For this purpose I employ a casting such as the collar d in Figure 16 which
carries a split ring such as 6 fixed to it in the manner above described, and I employ
another casting which carries a cylindrical casing such as a, the ring
expanded by the means described above or in any other suitable manner; these
castings are keyed or secured by straps one on each of the contiguous ends of the
shafts to be connected.
being
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
First. A shaft-coupling constructed with a muff or sleeve for supporting the
adjacent ends of the shafts and for communicating motion from one to the other of
the said shafts, and with straps for gripping the said shafts independently of each
other and suitably connected with the said muff or sleeve, for the purposes above
specified.
Second. The improved shaft-coupling comprising the muff or sleeve a and the
straps constructed and connected substantially as described with reference to
Figures 1 to 6 or with reference to Figures 7 to 12 of the drawings, for the
purposes above specified.
Third. The modification of my invention wherein I provide for the connection
of a pulley to a shaft by means of a sleeve or boss and strap, substantially as
described with reference to Figures 13, 14 and 15, of the drawings.

page_text: Fourth. The improved friction-clutch constructed with the split ring and the
means for expanding it, substantially as described with reference to Figures 16.
to 25 of the drawings and operating as, and for the purposes, above specified.
Dated this First day of September 1892.
D. Young & Co.,
GEO. P. WALKER.
11 & 12, Southampton Buildings, London, W.C., Agents for the Applicant.