Improvements in and relating to Friction Coupling Devices.
Year: 1892

page_text: Date of Application. 26th Sept., 1892-Accepted, 1st July, 1893
COMPLETE SPECIFICATION.
Improvements in and relating to Friction Coupling Devices.
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191, Fleet Street, in the City
of London, Civil Engineer and Chartered Patent Agent, do hereby declare the
nature of this invention (a communication to me from Marie Gawron, of 31,
Turnerstrasse, Stettin, in the Province of Pomerania, Kingdom of Prussia and
German Empire, Manufacturer,) 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 devices for coupling a driving shaft to a driven shaft by
means of friction set up between discs forced into contact with one another; its
objects being to increase the rapidity and to ensure the certainty of the action of
such devices, and to avoid shocks to the machinery.
In the accompanying drawings,
Fig. 1 is a view, partly in vertical section and partly in side elevation, of a
friction device constructed in the way in which it is preferred to carry out the
invention.
Fig. 2 is an end view in the planes indicated by the line A B (Fig. 1); Fig. 3
shewing a modification.
Figs. 4 and 5 are detail views.
Fig. 6 is a detail view illustrating a modification; Fig. 7 being a corresponding
end view in a plane indicated by the line C D.
Figs. 8 and 9 represent other modifications.
Figs. 10 to 12 shew the device previously illustrated with the addition of brake-
mechanism.
Figs. 13, 14 and 15 represent further modifications.
a and b are the two shafts which are to be united by means of the coupling. The
friction-disc c forms part of or is firmly united to the collar d, which is keyed on
the driving shaft b. The coupling-box fis keyed on the driven shaft a, and carries
two friction-discs h and h¹. The faces of the disc c are furnished with wedge-shaped
projections which fit in corresponding recesses in the opposing faces of the discs h
and h. The box can be formed so as to serve as a pulley, toothed wheel, or fly-
wheel, instead of acting as a coupling-box only. The friction-discs h and h¹ are
capable of being shifted in the box f along the shaft by means of spindles g, which
are mounted in the box f and provided with right and left screw-threads, so that,
by turning these spindles, the two friction-discs h and can be moved towards or
apart from one another. These movements of the friction-discs h and h¹ serve to
grip or to set free, as the case may be, the friction-disc c. In order that the
pressure of the discs may be sufficiently elastic, one of the two friction-discs h
and h-in the present instance h¹-comprises two separate parts h' and i, which are
connected with one another by a screw m. India-rubber cushions n (Fig. 1) or
springs m¹ (Fig. 8) are inserted between the two parts, so as to cause the discs h
and h¹ to bear with the elastic pressure required on the disc c.
The frictional
resistance of the coupling may be increased by inserting several intermediate discs,
as shewn in Figs. 6 and 8. In Fig. 6, there are two discs c and c' on the shaft and
three discs h, h¹ and 2 in the coupling-box; these discs having four available
friction-surfaces. In Fig. 8, there are three discs c, cl and c² on the shaft and four
discs h, h', h' and in the coupling-box; these discs having six effective friction-
surfaces.
In Fig. 6, the disc 2 is connected with the box f by means of the spindles g and
is placed between adjustable rings s on the spindles. The discs c and care capable
of lateral displacement on the collar d, and are forced apart from one another, after
the coupling is thrown out of action, by springs, such as z, as far as the rings or

page_text: projections p on the collar d will allow. In this way, friction between the various
discs after the coupling has been unlocked is completely avoided. In Fig. 8, the
middle disc e is rigidly fixed to the collar d. The discs 2 and 3 are forced by
means of springs, such as ¹, up to the rings s on the spindles g; the discs c¹ and c
being forced by the springs up to the projections or rings p' on the collar d.
22
The meaus employed for locking and unlocking the friction-discs above described
are as follow:-Chain-wheels 1, 2 and 3 are keyed on the spindles 9 (Figs. 1 and 2).
All the wheels 1 are connected together by a chain. This ensures an uniform grip
by the friction-discs h and h¹. On the shaft 6 is mounted the disconnecting device o,
which is provided with a conical friction-surface. This annular disconnecting
wedge o is moved laterally by the ring q attached to the lever '; being thereby
caused to slide along the key r, which causes it to rotate with the shaft. The
device, which also possesses a conical friction-surface, is likewise connected with
the lever q', and can consequently receive a lateral motion, but does not rotate with
the shaft b. The chain-wheel runs loosely on the shaft 6; the chain-wheel t also
running loosely on the part l. Both wheels possess conical friction-surfaces corre-
sponding to those of the parts o and . The wheels 2 are connected by the chain 2'
with the chain-wheel k, and the chain-wheels 3 by the chain 3' with the chain-
wheel t. When the lever q' and the part o are moved toward the left, the rotating
part o engages by friction with the wheel and carries it round with it, thus setting
in motion the chain-wheel 2, which effects a gradual and certain throwing into
action of the coupling device. When it is desired to throw the coupling out of
action, a reverse motion is given to the lever g'. This causes the conical friction-
surfaces of the part 1 and wheel t to grip one another. The part 7 hinders the
rotation of the chain-wheel t; the chain-wheels 3 being consequently set in motion
by the chain 31 in the opposite direction, so that the coupling device is gradually
thrown out of action.
If it be desired that the engaging and the disengaging of the coupling device
should take place at certain definite periods, a certain predetermined amount of
friction is produced in either case in the following manner :-Between the disc 6
(Fig. 4) and a flange on the part o is placed a collar provided with conical
friction-surfaces and projections x. By screwing up or unscrewing the nut 5 and
thereby varying the tension on the spring against it, the desired maximum degree
of resistance can be produced. In a similar manner, the collar w provided with
projections w is attached to the part l. The chain-wheel k is provided with
projections and the chain-wheel with projections t¹. When the lever q¹ and
with it the whole of the disconnecting gear is pushed toward the left, the projec-
tions engage with the projections ; the chain-wheel k being thereby set in
motion with the desired degree of force. If the lever q' be moved to the right,
then the projections and t engage with one another, the rotation of the chain-
wheel being consequently hindered to the desired extent, the coupling eventually
becoming unlocked. By regulating the amount of friction, the time necessarily
occupied in locking or unlocking the coupling can be varied at will. The unlocking
of the coupling may be effected by a chain and hand-wheel. Only the chain-wheel k
of the chain-wheels and t is then necessary, the projections k¹ engaging with the
corresponding projections 2 on the chain-wheel 3, which is connected with the
lever through the loose collar By turning the handle J attached to
the lever g', and consequently the chain-wheel H, the coupling can be locked or
unlocked provided the projections and t2 have been brought into engagement by
the moving of the lever q¹.
If it be desired to obtain increased power, the chain-wheels
and 3 are not
placed, as shewn in Fig. 1, directly on the spindle g, but the motion is transmitted
through suitable gear. Axles u (Fig. 3) run loosely in the frame fand, beside the
chain-wheels and 2, each carries a pinion s¹, which gears with a toothed wheel
fixed on the spindle g. The chain passes round the chain-wheels t. Greater
power is thus obtained. In order to effect a longitudinal displacement of the two
coupled shafts a and b, it is only necessary, in the arrangement shewn in Fig. 6, to

page_text: make the disc h² movable between the rings s. In that illustrated in Fig. 8, the
friction-disc e would not be in one piece with the collar d, but would be capable of
sliding thereon. If a transverse motion of the moving axles be necessary, it is best
to unite the spindles g not directly, but by means of links K and pins S with the
frame (Figs. 6 and 7).
In Fig. 9, the friction discs c¹ and c² are moved toward one another by screwed
spindles g', while the friction discs and are separated from one another, so far
as the projecting rings s on the pins g2 will allow, by the springs 2¹. The pins g
are connected to the frame f.
Figs. 10 and 12 represent a friction-disc coupling of the kind above described,
but provided with an automatic brake. The discs h, hand h², as well as the
brake-discs H and H', are so connected to the box f fixed on the shaft a that they
can be displaced laterally. The friction-discs h, 'h' and 2 are united by screwed
spindles g. In the design given by way of example there are four spindles g, of
which two lying opposite one another pass through the brake-discs H and H', as
well as through the box f. The brake-discs H and H' are united by screwed
spindles, which pass loosely through the box f. Each spindle y has a right-hand
screw-thread for the disc ', and a left-hand screw-thread for the disc h, or
vice versa. Similarly, each spindle i has a right-hand thread for the brake-disc H
and a left-hand thread for the brake-disc H, or vice versa. When the spindles and ¹
are turned in the same direction, the discs and and the brake-discs H
and H are either caused to approach toward or recede from one another. The
spindles are connected by chain-wheels * and chains 2, and so also are the
spindles when there are more than two of them. Each thread on the spindles g
and is a double or triple thread of such a pitch that when released after being
screwed up the reaction of the discs unscrews it. The action of these screws
resembles that of the screws used in stamping and minting, wherein, as soon as
the force causing the rotation of the screws is taken off, the screws rotate
backwards into their normal position. The spindles and are only used for
unlocking the coupling and brake; the locking of the same being effected by any
suitable springs, such as zx, arranged round the spindles. The spindles g and 2
can, however, be used for locking the coupling and brake, and the springs * for
unlocking the same. On the sleeve d* fixed to the shaft bare the friction-discs c,
and on the bearings y of the brake-sleeve /, which fits loosely on the shaft b and
cannot be either rotated or otherwise displaced, is the brake-disc ex. This brake-
disc can be moved longitudinally on the shaft, but cannot be rotated independently
thereon. The two spindles g (Fig. 11), lying opposite one another, carry the
unlocking arms w, which are rigidly attached to the spindles and are furnished with
counterbalances n*. The two spindles i, lying opposite one another, are provided
with unlocking arms w¹ rigidly attached to them and with the counterbalances n¹.
The counterbalances may be replaced by springs. q² m² m* r¹ (Fig. 12) is a
disconnector, which can be moved along the feather of the sleeve by the
lever O (shewn by a dotted line). The lever O prevents the rotation of the sleeve 15.
When very great power has to be transmitted, the sleeve can be held by an arm G
indicated by dotted lines in Fig. 12. is a collar and q² a disc. In Fig. 12, the
coupling is shewn locked with the brake-mechanism out of action. If it be desired
to unlock the coupling, the parts q², m², m* and r¹ are pressed toward the left;
the unlocking arms being thereupon raised by the can m² on to the disc q², and
consequently brought into a position corresponding with that of the arms w' in
Fig. 11. This so rotates the spindles g that the discs h and are caused to recede
from each other, and cease to have contact; the discs c and c¹ being also separated
by the springs. The coupling is thereupon unlocked. When the disconnector is
shifted to the left, the arms w' are brought by the counterbalances n² into a
position corresponding with that of the arms w in Fig. 11; the brake-gear being
made to act by the springs z*. If it be desired to lock the coupling, the
parts q, m², m* and r¹ are pushed toward the right, the coupling being thereupon

page_text: thrown into action, while the brake-mechanism becomes inoperative, the arms w¹
being raised on to the cylinder q2 and the brake-discs H and H' parted.
The rotary motion of the spindles g and i can be effected through gearing, as
illustrated in Fig. 10. In that figure, the spindle g is provided with a toothed
wheel 1, which gears with the spur-wheel 2* on the arm w. If the coupling be
required to work without a brake, then the brake-discs H, H' and c*, with the
spindles, as well as the sleeve are dispensed with.
The right-hand and left-hand serew-threads of the spindles g may be replaced by
one screw-thread only, which may be either right-hand or left-hand. In this case,
each thread engages with only one of the two friction discs; the spindle having a
collar which bears against the other friction-disc.
Fig. 12 shews such an arrangement. The spindle g has a screw-thread for
engaging with the middle friction-disc H, while the two outer friction-discs h and h¹
press against collars g' and g*. n³ are india-rubber rings. Each spindle g has two
rigid arms w* and w², one serving for locking the coupling and the other for locking
the brake. The springs * effect the unlocking.
The spindles g can also be screwed through one of the side-walls of the box f,
as shewn in Fig. 1. In this case, each spindle g has only one screw-thread, which
is of considerable pitch. The spindles serve to lock the coupling, and the
springs and to unlock it. Each spindle g is furnished with a toothed wheel 2,
which gears with the pinion k running loosely on the shaft b. The locking tube o
can be moved on the shaft b by means of the lever g, but it can only be moved in
the direction of the axis of the shaft. This tube carries the wedge-shaped disc
provided with projections a¹. The disc is held fast between the flange of the
tube o and the disc 6 by means of the bolt and nut 5. The spring cushion 3
enables the desired degree of friction to be attained. The box f rotates in the
direction indicated by the arrows. If it be desired to lock the arrangement, the
locking tube o is pushed toward the left, so that the projections a engage with
the projections of the pinion k. The rotation of the pinion k is then checked;
the wheels 2 being turned with the result that the friction-discs are drawn toward
one another, and become locked, thus effecting the coupling, whereupon the
friction-discs and a slide round until eventually they turn at the same speed as
the shaft. If it be desired to unlock the arrangement, then the locking tube o is
moved to the right, whereupon the springs 3 and 2 separate the friction-discs and
bring back the spindles with the toothed wheels 2 and the wheel k into their
original positions. In order to make the pressure of the friction-discs elastic, the
india-rubber ring n is provided in the coupling-box.
In Figs. 13 and 14 is shewn a modified form of the coupling illustrated in Fig. 1.
The friction-disc c, provided on both sides with plain or conical friction surfaces,
is pivoted by the spindle y' to the box f. The disc can be moved to a slight extent
along the spindle. On each side of the disc c is arranged a friction-disc h or h¹
provided with corresponding friction-surfaces. The disc is fixed to the sleeve d
attached to the shaft, but the dise h¹ can be moved upon the said sleeve. On the
prolongation of the sleeve d, the pressure-collar e having two flanges is screwed.
Between the flanges are placed the discs and 2, which are tightened by means
of the adjusting screw p². The india-rubber ring o' causes the pressure to be an
elastic one.
The disc can only be moved longitudinally on the collar e, but the
disc k² can be moved both longitudinally and rotatively. The disc k² has on its
outer surface two teeth s* (Fig. 14) and two projections . By turning the collar e
either to the right or to the left, the friction-discs h, c and h¹ are either brought up
to one another, which results in locking the coupling, or are parted from one
another to unlock the same. The teeth s✶ of the disc 2 are caught by the
catches S¹ in the box f. A disconnector v² u² q³ p² m** runs loosely on the shaft b,
and can be moved longitudinally by the lever m**. q³ is a disc, 72 is a collar,
and u² are two cams, which pass into the disc q³. are projections which engage
with the projections of the disc ³, Outside the box f, the springs are

page_text: connected with the catches S, and keep these in engagement with the teeth se ΟΙ
the disc k².
The method of effecting the coupling is as follows:-If it be desired to lock the
same, the lever mxx is pushed to the right. The catches S', actuated by the
springs and moving in the direction of the arrow in Fig. 14, then engage with
the teeth of the disc 2, the collar e being thereupon moved by the frictional
resistance set up between the discs 2 and k². The friction discs are thus brought
tightly together; the coupling of the shaft b being thus effected. If it be desired
to unlock the coupling, then the lever m** is pushed to the left; thereupon the
arms 10* are lifted by the cams u² on to the disc q³, and the catches S₁ are moved
out of engagement with the teeth s*. On the lever mxx being moved further in
the same direction, the projections v² engage with the projections t* on the disc 2.
In this way, the movement of the disc k² is retarded; the collar e becoming
screwed up by the frictional resistance established between the discs i² and k²; and
the coupling is loosened. The springs 1× and 2× separate the friction-discs and ¹
from one another, so that contact between them and the friction disc is avoided
when the coupling is loose. The frictional resistance between the discs 2 and k²
acts during the loosening of the coupling as a brake upon the driving shaft. Such
friction can be increased by introducing several pairs of discs. The discs
may have conical friction-surfaces, if preferred.
and k²
In order to increase the frictional resistance for a given pressure of the collar,
several friction-discs may be introduced, as represented in Fig. 15. The coupling
and the uncoupling is in this case effected differently. The collar e, containing the
regulating screw p², the disc and the india-rubber ring o', is screwed into the
box f. The right-hand part of the collar e has two conical friction-rings set
opposite one another, which can be brought into contact with the corresponding
friction-rings 5' and 6' of the coupling and uncoupling device Q. The part of
the device with the friction-ring 51 and the ring 7 can be moved longitudinally
by the lever y along the feather 7 of the driving shaft a, but is compelled to rotate
with that shaft. The part 2, with the other friction-ring 6', is placed on the
part, is also connected with the lever y, and can be moved longitudinally on but
does not rotate with the said part *. If the device Q be pushed to the left, then
the driving friction-ring 5' comes into contact with the friction-surface 3* on the
collar e; the latter, being thus caused to rotate with the driving shaft a, screws
further into the box f, and the discs become firmly pressed together to effect the
coupling. If it be desired to uncouple, the device Q is pushed toward the right
until the rings 6' and 4' come into contact. The rotation of the ring 4' is then
checked by the stationary ring 6¹ and finally stopped, the collar e being con-
sequently unscrewed out of the coupling box to effect the uncoupling.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I claim :-
1. A coupling comprising friction-discs, such as h and h', or h, h¹ and h², which
are provided with conical or flat friction-surfaces, are so arranged in the coupling-
box as to be only capable of displacement in the direction of their axes, and can
be pressed toward or caused to recede from one another, by means of screws g or of
a screwed collar e, for the purpose of engaging or disengaging a friction-disc or
discs, such as c, arranged on the sleeve d so as to be capable of displacement only
in the direction of the axis of the shaft; the locking or unlocking of the coupling
being effected by the engagement or disengagement of the discs.
2. In a coupling of the kind illustrated in Fig. 8 of the accompanying drawings,
forcing the intermediate discs, such as c' and c², and 2 and 3, in the direction of the
axis of the shaft by means of springs, such as z, z¹ and 2, until they respectively
reach the stops p' and s, the coupling being thus completely disconnected.
3. A contrivance for coupling and uncoupling shafts, capable of being worked
while the machinery is being driven, and comprising a device o lq q', of which the
part o, movable along the feather r on the driving shaft b, provided with a conical

page_text: friction-surface, and connected with the lever g' through the ring 9, rotates with the
said shaft, while the part placed on the part e, and also possessing a conical
friction-surface, is connected with the lever in such a way that it is capable of
being moved longitudinally with the part o by that lever but can not rotate; a loose
chain-wheel k possessing a conical friction-surface adapted for the part o to engage
with, the chain-wheel being connected either directly or indirectly with the
spindles g by chain-wheels 2° and a chain 2¹; a chain-wheel t running loosely on
the neck of the part 1, having a conical friction-surface corresponding with that of
the part 1, and connected either directly or indirectly with the spindles g by chain-
wheels 3 and a chain 31; the chain-wheel & turning by friction with the part o of the
disconnector oq q' when the latter is moved toward the left, the screws g being
thereupon rotated by the chain-wheels 2 and chain 2¹ to effect the coupling, while
the chain-wheel t is brought to rest by the part 1 of the disconnector when the latter
is moved toward the right, the screws g being then turned by the chain-wheels 3 and
the chain 3 in the opposite direction to effect the uncoupling.
4. A contrivance for coupling and uncoupling shafts comprising the device
illustrated in Fig. 4 of the accompanying drawings, in which the parts o and 1 of
the disconnector are provided respectively with a friction-ring or w subjected to
an elastic pressure, the rings having projections a¹ and w¹ to engage with corre-
sponding projections and t¹ on the chain-wheels k and t, so that, when the
disconnector is moved to the left, the projections and ' engage with one another,
and, when moved to the right, the projections w' and t¹ engage with one another, by
which means a gradual frictional resistance regulated according to requirements is
brought to bear upon the chain-wheels k and t, in order that the coupling and
uncoupling can be effected either slowly or quickly.
5. A contrivance for coupling and uncoupling shafts comprising the device
illustrated in Fig. 5 of the accompanying drawings, in which the coupling and
uncoupling is directly effected by means of a chain r, a chain-wheel t³ and a chain-
wheel H mounted on the lever and having a handle J, the chain-wheel k with
the projections being used for acting on the discs, the said chain-wheel k
engaging with the projections on the chain-wheel 3 when the lever g' is moved
toward the left, whereupon, by turning the handle J in one direction or the other
the coupling can be thrown into or out of action.
6. In a coupling of the kind herein referred to, the employment of brake-
mechanism as described with reference to Figs. 10 to 12 of the accompanying
drawings, such mechanism comprising a stationary sleeve l, a brake-disc or -discs,
such as c, arranged to slide in the direction of the axis of the shaft, and brake-
discs, such as H. and H, connected with the box f and capable of displacement in
the direction of their axes, and which are thrown into action by springs z* and
thrown out of action by screw-spindles, the brake-mechanism acting when the
coupling is unlocked and being thrown out of gear when the coupling is effected.
7. In a coupling of the kind herein referred to, the employment of means for
locking and unlocking which can be operated while the machinery is running,
the same comprising a disconnector q² m² m* r¹ and a lever O, which, when moved
to the left, causes counterbalanced arms w to be raised by the cam m² on to the
disc q², the coupling being thus either directly or indirectly unlocked and the brake-
mechanism thrown into action by means of springs * and counterbalanced arms w¹,
the movement of the lever in the reverse direction locking the coupling and throwing
the brake-mechanism out of action.
8. In a contrivance of the kind herein referred to, the employment of a coupling
and uncoupling device worked while the machinery is running substantially as
described with reference to Fig. 13 of the accompanying drawings, and comprising
discs and k² pressed together elastically between the side-walls and n of the
collare by means of a screw p², the discs 2 being incapable of independent
rotation on the collar e, while the disc has teeth s* and projections t* adapted to
engage with the teeth ³, so that, on moving the disconnector vu² g³ ³ mxx to the
right, the catches S¹ pivoted in the coupling f are made to hold the teeth s* of the

page_text: disc by the action of the springs 25, the sleeve being thereby set rotating in
order to press together the friction-discs h', e and h, and thus effect the coupling,
while, by moving the disconnector to the left, the catches S' are raised and the
projections engage with the teeth 2, the discs e and being thus parted to effect
the uncoupling, whereupon the frictional resistance between the discs and k² acts
as a brake upon the disconnected shaft.
9. In a contrivance of the kind herein referred to, the employment of a locking
and unlocking device substantially as described with reference to Fig. 15 of the
accompanying drawings, the same comprising the parts * q* x² y, of which the
part is capable of displacement along the key 7 of the driving shaft a, is provided
with a conical friction-ring 5¹, is connected with the lever y by the ring q*, and
turns with the shaft a, while the part 2 placed on the part and possessing a
conical friction-ring 61 is so connected with the lever y that it can be moved thereby
simultaneously with the part in the direction of the axis of the shaft, so that,
when the lever y is pushed to the left, the rotating friction-ring 51 grips the friction-
surface 3* of the collar e, and the latter is caused to rotate with the driving shaft a,
the coupling in consequence becoming locked, while, when the disconnector is
moved to the right, the stationary friction-ring 61 grips the friction-surface 4' of the
collar e, whereby the latter is stopped and forthwith unscrewed, the coupling
becoming unlocked.
10. The improved friction coupling device constructed and operating substantially
as described with reference to the accompanying drawings.
11. The friction coupling device combined with brake mechanism constructed
and operating substantially as described with reference to the accompanying
drawings.
Dated the 12th day of August 1892.
G. G. M. HARDINGHAM.